From 89d17b9604ae502392e119dbdbf43f6067745715 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Tue, 20 Jun 2006 00:39:19 -0400 Subject: [AGPGART] Whitespace cleanups for ati-agp Signed-off-by: Dave Jones --- drivers/char/agp/ati-agp.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/char/agp/ati-agp.c b/drivers/char/agp/ati-agp.c index 06fd10ba0c5..6db9b7f436a 100644 --- a/drivers/char/agp/ati-agp.c +++ b/drivers/char/agp/ati-agp.c @@ -41,7 +41,6 @@ static struct gatt_mask ati_generic_masks[] = }; - typedef struct _ati_page_map { unsigned long *real; unsigned long __iomem *remapped; @@ -141,7 +140,8 @@ static int ati_create_gatt_pages(int nr_tables) ati_generic_private.num_tables = nr_tables; ati_generic_private.gatt_pages = tables; - if (retval != 0) ati_free_gatt_pages(); + if (retval != 0) + ati_free_gatt_pages(); return retval; } @@ -219,16 +219,16 @@ static int ati_configure(void) ati_generic_private.registers = (volatile u8 __iomem *) ioremap(temp, 4096); if (is_r200()) - pci_write_config_dword(agp_bridge->dev, ATI_RS100_IG_AGPMODE, 0x20000); + pci_write_config_dword(agp_bridge->dev, ATI_RS100_IG_AGPMODE, 0x20000); else pci_write_config_dword(agp_bridge->dev, ATI_RS300_IG_AGPMODE, 0x20000); /* address to map too */ - /* + /* pci_read_config_dword(agp_bridge.dev, AGP_APBASE, &temp); agp_bridge.gart_bus_addr = (temp & PCI_BASE_ADDRESS_MEM_MASK); printk(KERN_INFO PFX "IGP320 gart_bus_addr: %x\n", agp_bridge.gart_bus_addr); - */ + */ writel(0x60000, ati_generic_private.registers+ATI_GART_FEATURE_ID); readl(ati_generic_private.registers+ATI_GART_FEATURE_ID); /* PCI Posting.*/ @@ -321,9 +321,9 @@ static int ati_remove_memory(struct agp_memory * mem, off_t pg_start, unsigned long __iomem *cur_gatt; unsigned long addr; - if (type != 0 || mem->type != 0) { + if (type != 0 || mem->type != 0) return -EINVAL; - } + for (i = pg_start; i < (mem->page_count + pg_start); i++) { addr = (i * PAGE_SIZE) + agp_bridge->gart_bus_addr; cur_gatt = GET_GATT(addr); @@ -502,9 +502,8 @@ found: bridge->dev = pdev; bridge->capndx = cap_ptr; - - bridge->driver = &ati_generic_bridge; + bridge->driver = &ati_generic_bridge; printk(KERN_INFO PFX "Detected Ati %s chipset\n", devs[j].chipset_name); -- cgit v1.2.3 From a4aec2622340e356e7dcd0e8fd05378dacb71c89 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Tue, 20 Jun 2006 00:42:04 -0400 Subject: [AGPGART] Suspend/Resume improvements for ATI AGP Based on patches in the Ubuntu kernel. Signed-off-by: Ben Collins Signed-off-by: Dave Jones --- drivers/char/agp/ati-agp.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/char/agp/ati-agp.c b/drivers/char/agp/ati-agp.c index 6db9b7f436a..34bbd41f062 100644 --- a/drivers/char/agp/ati-agp.c +++ b/drivers/char/agp/ati-agp.c @@ -245,18 +245,20 @@ static int ati_configure(void) #ifdef CONFIG_PM -static int agp_ati_resume(struct pci_dev *dev) +static int agp_ati_suspend(struct pci_dev *dev, pm_message_t state) { - pci_restore_state(dev); + pci_save_state(dev); + pci_set_power_state (pdev, 3); - return ati_configure(); + return 0; } -static int agp_ati_suspend(struct pci_dev *dev, pm_message_t state) +static int agp_ati_resume(struct pci_dev *dev) { - pci_save_state(dev); + pci_set_power_state (pdev, 0); + pci_restore_state(dev); - return 0; + return ati_configure(); } #endif @@ -545,8 +547,8 @@ static struct pci_driver agp_ati_pci_driver = { .probe = agp_ati_probe, .remove = agp_ati_remove, #ifdef CONFIG_PM - .resume = agp_ati_resume, .suspend = agp_ati_suspend, + .resume = agp_ati_resume, #endif }; -- cgit v1.2.3 From c5f2f261e7a47e4c72723cdcbe99e1bd771a81ea Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Tue, 20 Jun 2006 00:44:38 -0400 Subject: [AGPGART] Suspend/Resume support for nVidia nForce AGP. Based on a patch from the Ubuntu kernel. Signed-off-by: Ben Collins Signed-off-by: Dave Jones --- drivers/char/agp/nvidia-agp.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/drivers/char/agp/nvidia-agp.c b/drivers/char/agp/nvidia-agp.c index 4c67135c12d..b3a53e7f360 100644 --- a/drivers/char/agp/nvidia-agp.c +++ b/drivers/char/agp/nvidia-agp.c @@ -376,6 +376,31 @@ static void __devexit agp_nvidia_remove(struct pci_dev *pdev) agp_put_bridge(bridge); } +#ifdef CONFIG_PM +static int agp_nvidia_suspend(struct pci_dev *pdev, pm_message_t state) +{ + pci_save_state (pdev); + pci_set_power_state (pdev, 3); + + return 0; +} + +static int agp_nvidia_resume(struct pci_dev *pdev) +{ + struct agp_bridge_data *bridge = pci_get_drvdata(pdev); + + /* set power state 0 and restore PCI space */ + pci_set_power_state (pdev, 0); + pci_restore_state(pdev); + + /* reconfigure AGP hardware again */ + nvidia_configure(); + + return 0; +} +#endif + + static struct pci_device_id agp_nvidia_pci_table[] = { { .class = (PCI_CLASS_BRIDGE_HOST << 8), @@ -403,6 +428,10 @@ static struct pci_driver agp_nvidia_pci_driver = { .id_table = agp_nvidia_pci_table, .probe = agp_nvidia_probe, .remove = agp_nvidia_remove, +#ifdef CONFIG_PM + .suspend = agp_nvidia_suspend, + .resume = agp_nvidia_resume, +#endif }; static int __init agp_nvidia_init(void) -- cgit v1.2.3 From b3818ed446fc41db41b5a38d934ac2b69fd2e0aa Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Wed, 21 Jun 2006 13:10:26 -0400 Subject: [AGPGART] Compile fix for ati-agp Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- drivers/char/agp/ati-agp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/char/agp/ati-agp.c b/drivers/char/agp/ati-agp.c index 34bbd41f062..d712078ed82 100644 --- a/drivers/char/agp/ati-agp.c +++ b/drivers/char/agp/ati-agp.c @@ -248,14 +248,14 @@ static int ati_configure(void) static int agp_ati_suspend(struct pci_dev *dev, pm_message_t state) { pci_save_state(dev); - pci_set_power_state (pdev, 3); + pci_set_power_state(dev, 3); return 0; } static int agp_ati_resume(struct pci_dev *dev) { - pci_set_power_state (pdev, 0); + pci_set_power_state(dev, 0); pci_restore_state(dev); return ati_configure(); -- cgit v1.2.3 From 4092e256ca35e62b431ebad4e0c42c6360acee08 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Wed, 21 Jun 2006 17:36:24 -0400 Subject: [AGPGART] Fix pci_register_driver checking in amd64-agp pci_register_driver() never returns a positive number. Signed-off-by: Dave Jones --- drivers/char/agp/amd64-agp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c index ac3c33a2e37..e449d949f7e 100644 --- a/drivers/char/agp/amd64-agp.c +++ b/drivers/char/agp/amd64-agp.c @@ -761,7 +761,7 @@ int __init agp_amd64_init(void) if (agp_off) return -EINVAL; - if (pci_register_driver(&agp_amd64_pci_driver) > 0) { + if (pci_register_driver(&agp_amd64_pci_driver) < 0) { struct pci_dev *dev; if (!agp_try_unsupported && !agp_try_unsupported_boot) { printk(KERN_INFO PFX "No supported AGP bridge found.\n"); -- cgit v1.2.3 From 4280370efe0e9c527ccd6188d6211a10bcb22b1e Mon Sep 17 00:00:00 2001 From: Adrian Bunk Date: Fri, 23 Jun 2006 12:55:46 +0200 Subject: [AGPGART] remove unused variable This patch removes an unused variable. Signed-off-by: Adrian Bunk Signed-off-by: Dave Jones --- drivers/char/agp/nvidia-agp.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/char/agp/nvidia-agp.c b/drivers/char/agp/nvidia-agp.c index b3a53e7f360..df7f37b2739 100644 --- a/drivers/char/agp/nvidia-agp.c +++ b/drivers/char/agp/nvidia-agp.c @@ -387,8 +387,6 @@ static int agp_nvidia_suspend(struct pci_dev *pdev, pm_message_t state) static int agp_nvidia_resume(struct pci_dev *pdev) { - struct agp_bridge_data *bridge = pci_get_drvdata(pdev); - /* set power state 0 and restore PCI space */ pci_set_power_state (pdev, 0); pci_restore_state(pdev); -- cgit v1.2.3 From 46f18e3a28295a9e11a6ffa4478241c19bc93735 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Mon, 26 Jun 2006 00:34:43 -0400 Subject: ACPI: HW P-state coordination support Treat HW coordination as independent CPUs. This enables per-cpu monintoring of P-states http://bugzilla.kernel.org/show_bug.cgi?id=5737 Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c | 8 +++++++- arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c | 8 +++++++- drivers/acpi/processor_perflib.c | 8 ++++---- include/linux/cpufreq.h | 6 ++++-- 4 files changed, 22 insertions(+), 8 deletions(-) diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c index 5fd65325b81..cf0ddc9ee0c 100644 --- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -418,8 +418,14 @@ acpi_cpufreq_cpu_init ( goto err_free; perf = data->acpi_data; - policy->cpus = perf->shared_cpu_map; policy->shared_type = perf->shared_type; + /* + * Will let policy->cpus know about dependency only when software + * coordination is required. + */ + if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL || + policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) + policy->cpus = perf->shared_cpu_map; if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) { acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS; diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c index f7e4356f682..8d765509ef5 100644 --- a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c +++ b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c @@ -399,8 +399,14 @@ static int centrino_cpu_init_acpi(struct cpufreq_policy *policy) dprintk(PFX "obtaining ACPI data failed\n"); return -EIO; } - policy->cpus = p->shared_cpu_map; policy->shared_type = p->shared_type; + /* + * Will let policy->cpus know about dependency only when software + * coordination is required. + */ + if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL || + policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) + policy->cpus = p->shared_cpu_map; /* verify the acpi_data */ if (p->state_count <= 1) { diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 41aaaba74b1..299fbbb07e0 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -698,12 +698,12 @@ int acpi_processor_preregister_performance( /* Validate the Domain info */ count_target = pdomain->num_processors; count = 1; - if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL || - pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) { + if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL; - } else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) { + else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) + pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW; + else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY; - } for_each_possible_cpu(j) { if (i == j) diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 466fbe9e489..35e137636b0 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -100,8 +100,10 @@ struct cpufreq_policy { #define CPUFREQ_INCOMPATIBLE (1) #define CPUFREQ_NOTIFY (2) -#define CPUFREQ_SHARED_TYPE_ALL (0) /* All dependent CPUs should set freq */ -#define CPUFREQ_SHARED_TYPE_ANY (1) /* Freq can be set from any dependent CPU */ +#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ +#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ +#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ +#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ /******************** cpufreq transition notifiers *******************/ -- cgit v1.2.3 From d8deac5094988c7ad1127ee61f52c59a952fcabb Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 20 Jun 2005 21:15:16 -0700 Subject: [PATCH] devfs: Remove devfs from the kernel tree This is the first patch in a series of patches that removes devfs support from the kernel. This patch removes the core devfs code, and its private header file. Signed-off-by: Greg Kroah-Hartman --- fs/Makefile | 1 - fs/compat_ioctl.c | 1 - fs/devfs/Makefile | 8 - fs/devfs/base.c | 2836 --------------------------------------- fs/devfs/util.c | 97 -- include/linux/compat_ioctl.h | 5 - include/linux/devfs_fs.h | 41 - include/linux/devfs_fs_kernel.h | 18 - 8 files changed, 3007 deletions(-) delete mode 100644 fs/devfs/Makefile delete mode 100644 fs/devfs/base.c delete mode 100644 fs/devfs/util.c delete mode 100644 include/linux/devfs_fs.h diff --git a/fs/Makefile b/fs/Makefile index d0ea6bfccf2..89135428a53 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -66,7 +66,6 @@ obj-$(CONFIG_MSDOS_FS) += msdos/ obj-$(CONFIG_VFAT_FS) += vfat/ obj-$(CONFIG_BFS_FS) += bfs/ obj-$(CONFIG_ISO9660_FS) += isofs/ -obj-$(CONFIG_DEVFS_FS) += devfs/ obj-$(CONFIG_HFSPLUS_FS) += hfsplus/ # Before hfs to find wrapped HFS+ obj-$(CONFIG_HFS_FS) += hfs/ obj-$(CONFIG_VXFS_FS) += freevxfs/ diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index d8ecfedef18..d8d50a70c58 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -44,7 +44,6 @@ #include #include #include -#include #include #include #include diff --git a/fs/devfs/Makefile b/fs/devfs/Makefile deleted file mode 100644 index 6dd8d1245e2..00000000000 --- a/fs/devfs/Makefile +++ /dev/null @@ -1,8 +0,0 @@ -# -# Makefile for the linux devfs-filesystem routines. -# - -obj-$(CONFIG_DEVFS_FS) += devfs.o - -devfs-objs := base.o util.o - diff --git a/fs/devfs/base.c b/fs/devfs/base.c deleted file mode 100644 index 51a97f13274..00000000000 --- a/fs/devfs/base.c +++ /dev/null @@ -1,2836 +0,0 @@ -/* devfs (Device FileSystem) driver. - - Copyright (C) 1998-2002 Richard Gooch - - This library is free software; you can redistribute it and/or - modify it under the terms of the GNU Library General Public - License as published by the Free Software Foundation; either - version 2 of the License, or (at your option) any later version. - - This library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Library General Public License for more details. - - You should have received a copy of the GNU Library General Public - License along with this library; if not, write to the Free - Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - - Richard Gooch may be reached by email at rgooch@atnf.csiro.au - The postal address is: - Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia. - - ChangeLog - - 19980110 Richard Gooch - Original version. - v0.1 - 19980111 Richard Gooch - Created per-fs inode table rather than using inode->u.generic_ip - v0.2 - 19980111 Richard Gooch - Created .epoch inode which has a ctime of 0. - Fixed loss of named pipes when dentries lost. - Fixed loss of inode data when devfs_register() follows mknod(). - v0.3 - 19980111 Richard Gooch - Fix for when compiling with CONFIG_KERNELD. - 19980112 Richard Gooch - Fix for readdir() which sometimes didn't show entries. - Added <> option to . - v0.4 - 19980113 Richard Gooch - Created function. - v0.5 - 19980115 Richard Gooch - Added subdirectory support. Major restructuring. - 19980116 Richard Gooch - Fixed to not search major=0,minor=0. - Added symlink support. - v0.6 - 19980120 Richard Gooch - Created function and support directory unregister - 19980120 Richard Gooch - Auto-ownership uses real uid/gid rather than effective uid/gid. - v0.7 - 19980121 Richard Gooch - Supported creation of sockets. - v0.8 - 19980122 Richard Gooch - Added DEVFS_FL_HIDE_UNREG flag. - Interface change to . - Created to support symlink(2). - v0.9 - 19980123 Richard Gooch - Added check to to check inode is in devfs. - Added optional traversal of symlinks. - v0.10 - 19980124 Richard Gooch - Created and . - v0.11 - 19980125 C. Scott Ananian - Created . - 19980125 Richard Gooch - Allow removal of symlinks. - v0.12 - 19980125 Richard Gooch - Created . - 19980126 Richard Gooch - Moved DEVFS_SUPER_MAGIC into header file. - Added DEVFS_FL_HIDE flag. - Created . - Created . - Fixed minor bug in . - 19980127 Richard Gooch - Changed interface to , , - , and . - Fixed inode times when symlink created with symlink(2). - v0.13 - 19980129 C. Scott Ananian - Exported , - and . - 19980129 Richard Gooch - Created to support unlink(2). - v0.14 - 19980129 Richard Gooch - Fixed kerneld support for entries in devfs subdirectories. - 19980130 Richard Gooch - Bugfixes in . - v0.15 - 19980207 Richard Gooch - Call kerneld when looking up unregistered entries. - v0.16 - 19980326 Richard Gooch - Modified interface to for symlink traversal. - v0.17 - 19980331 Richard Gooch - Fixed persistence bug with device numbers for manually created - device files. - Fixed problem with recreating symlinks with different content. - v0.18 - 19980401 Richard Gooch - Changed to CONFIG_KMOD. - Hide entries which are manually unlinked. - Always invalidate devfs dentry cache when registering entries. - Created to support rmdir(2). - Ensure directories created by are visible. - v0.19 - 19980402 Richard Gooch - Invalidate devfs dentry cache when making directories. - Invalidate devfs dentry cache when removing entries. - Fixed persistence bug with fifos. - v0.20 - 19980421 Richard Gooch - Print process command when debugging kerneld/kmod. - Added debugging for register/unregister/change operations. - 19980422 Richard Gooch - Added "devfs=" boot options. - v0.21 - 19980426 Richard Gooch - No longer lock/unlock superblock in . - Drop negative dentries when they are released. - Manage dcache more efficiently. - v0.22 - 19980427 Richard Gooch - Added DEVFS_FL_AUTO_DEVNUM flag. - v0.23 - 19980430 Richard Gooch - No longer set unnecessary methods. - v0.24 - 19980504 Richard Gooch - Added PID display to debugging message. - Added "after" debugging message to . - 19980519 Richard Gooch - Added "diread" and "diwrite" boot options. - 19980520 Richard Gooch - Fixed persistence problem with permissions. - v0.25 - 19980602 Richard Gooch - Support legacy device nodes. - Fixed bug where recreated inodes were hidden. - v0.26 - 19980602 Richard Gooch - Improved debugging in . - 19980607 Richard Gooch - No longer free old dentries in . - Free all dentries for a given entry when deleting inodes. - v0.27 - 19980627 Richard Gooch - Limit auto-device numbering to majors 128 to 239. - v0.28 - 19980629 Richard Gooch - Fixed inode times persistence problem. - v0.29 - 19980704 Richard Gooch - Fixed spelling in debug. - Fixed bug in parsing "dilookup". - v0.30 - 19980705 Richard Gooch - Fixed devfs inode leak when manually recreating inodes. - Fixed permission persistence problem when recreating inodes. - v0.31 - 19980727 Richard Gooch - Removed harmless "unused variable" compiler warning. - Fixed modes for manually recreated device nodes. - v0.32 - 19980728 Richard Gooch - Added NULL devfs inode warning in . - Force all inode nlink values to 1. - v0.33 - 19980730 Richard Gooch - Added "dimknod" boot option. - Set inode nlink to 0 when freeing dentries. - Fixed modes for manually recreated symlinks. - v0.34 - 19980802 Richard Gooch - Fixed bugs in recreated directories and symlinks. - v0.35 - 19980806 Richard Gooch - Fixed bugs in recreated device nodes. - 19980807 Richard Gooch - Fixed bug in currently unused . - Defined new type. - Improved debugging when getting entries. - Fixed bug where directories could be emptied. - v0.36 - 19980809 Richard Gooch - Replaced dummy .epoch inode with .devfsd character device. - 19980810 Richard Gooch - Implemented devfsd protocol revision 0. - v0.37 - 19980819 Richard Gooch - Added soothing message to warning in . - v0.38 - 19980829 Richard Gooch - Use GCC extensions for structure initialisations. - Implemented async open notification. - Incremented devfsd protocol revision to 1. - v0.39 - 19980908 Richard Gooch - Moved async open notification to end of . - v0.40 - 19980910 Richard Gooch - Prepended "/dev/" to module load request. - Renamed to . - v0.41 - 19980910 Richard Gooch - Fixed typo "AYSNC" -> "ASYNC". - v0.42 - 19980910 Richard Gooch - Added open flag for files. - v0.43 - 19980927 Richard Gooch - Set i_blocks=0 and i_blksize=1024 in . - v0.44 - 19981005 Richard Gooch - Added test for empty <> in . - Renamed to and published. - v0.45 - 19981006 Richard Gooch - Created . - v0.46 - 19981007 Richard Gooch - Limit auto-device numbering to majors 144 to 239. - v0.47 - 19981010 Richard Gooch - Updated for VFS change in 2.1.125. - v0.48 - 19981022 Richard Gooch - Created DEVFS_ FL_COMPAT flag. - v0.49 - 19981023 Richard Gooch - Created "nocompat" boot option. - v0.50 - 19981025 Richard Gooch - Replaced "mount" boot option with "nomount". - v0.51 - 19981110 Richard Gooch - Created "only" boot option. - v0.52 - 19981112 Richard Gooch - Added DEVFS_FL_REMOVABLE flag. - v0.53 - 19981114 Richard Gooch - Only call on first call to - . - v0.54 - 19981205 Richard Gooch - Updated for VFS change in 2.1.131. - v0.55 - 19981218 Richard Gooch - Created . - 19981220 Richard Gooch - Check for partitions on removable media in . - v0.56 - 19990118 Richard Gooch - Added support for registering regular files. - Created . - Update devfs inodes from entries if not changed through FS. - v0.57 - 19990124 Richard Gooch - Fixed to only initialise temporary inodes. - Trap for NULL fops in . - Return -ENODEV in for non-driver inodes. - v0.58 - 19990126 Richard Gooch - Switched from PATH_MAX to DEVFS_PATHLEN. - v0.59 - 19990127 Richard Gooch - Created "nottycompat" boot option. - v0.60 - 19990318 Richard Gooch - Fixed to not overrun event buffer. - v0.61 - 19990329 Richard Gooch - Created . - v0.62 - 19990330 Richard Gooch - Don't return unregistred entries in . - Panic in if entry unregistered. - 19990401 Richard Gooch - Don't panic in for duplicates. - v0.63 - 19990402 Richard Gooch - Don't unregister already unregistered entries in . - v0.64 - 19990510 Richard Gooch - Disable warning messages when unable to read partition table for - removable media. - v0.65 - 19990512 Richard Gooch - Updated for VFS change in 2.3.1-pre1. - Created "oops-on-panic" boot option. - Improved debugging in and . - v0.66 - 19990519 Richard Gooch - Added documentation for some functions. - 19990525 Richard Gooch - Removed "oops-on-panic" boot option: now always Oops. - v0.67 - 19990531 Richard Gooch - Improved debugging in . - v0.68 - 19990604 Richard Gooch - Added "diunlink" and "nokmod" boot options. - Removed superfluous warning message in . - v0.69 - 19990611 Richard Gooch - Took account of change to . - v0.70 - 19990614 Richard Gooch - Created separate event queue for each mounted devfs. - Removed . - Created new ioctl()s. - Incremented devfsd protocol revision to 3. - Fixed bug when re-creating directories: contents were lost. - Block access to inodes until devfsd updates permissions. - 19990615 Richard Gooch - Support 2.2.x kernels. - v0.71 - 19990623 Richard Gooch - Switched to sending process uid/gid to devfsd. - Renamed to . - Added DEVFSD_NOTIFY_LOOKUP event. - 19990624 Richard Gooch - Added DEVFSD_NOTIFY_CHANGE event. - Incremented devfsd protocol revision to 4. - v0.72 - 19990713 Richard Gooch - Return EISDIR rather than EINVAL for read(2) on directories. - v0.73 - 19990809 Richard Gooch - Changed to new __init scheme. - v0.74 - 19990901 Richard Gooch - Changed remaining function declarations to new __init scheme. - v0.75 - 19991013 Richard Gooch - Created , , - and . - Added <> parameter to , , - and . - Work sponsored by SGI. - v0.76 - 19991017 Richard Gooch - Allow multiple unregistrations. - Work sponsored by SGI. - v0.77 - 19991026 Richard Gooch - Added major and minor number to devfsd protocol. - Incremented devfsd protocol revision to 5. - Work sponsored by SGI. - v0.78 - 19991030 Richard Gooch - Support info pointer for all devfs entry types. - Added <> parameter to and - . - Work sponsored by SGI. - v0.79 - 19991031 Richard Gooch - Support "../" when searching devfs namespace. - Work sponsored by SGI. - v0.80 - 19991101 Richard Gooch - Created . - Work sponsored by SGI. - v0.81 - 19991103 Richard Gooch - Exported . - Work sponsored by SGI. - v0.82 - 19991104 Richard Gooch - Removed unused . - 19991105 Richard Gooch - Do not hide entries from devfsd or children. - Removed DEVFS_ FL_TTY_COMPAT flag. - Removed "nottycompat" boot option. - Removed . - Work sponsored by SGI. - v0.83 - 19991107 Richard Gooch - Added DEVFS_FL_WAIT flag. - Work sponsored by SGI. - v0.84 - 19991107 Richard Gooch - Support new "disc" naming scheme in . - Allow NULL fops in . - Work sponsored by SGI. - v0.85 - 19991110 Richard Gooch - Fall back to major table if NULL fops given to . - Work sponsored by SGI. - v0.86 - 19991204 Richard Gooch - Support fifos when unregistering. - Work sponsored by SGI. - v0.87 - 19991209 Richard Gooch - Removed obsolete DEVFS_ FL_COMPAT and DEVFS_ FL_TOLERANT flags. - Work sponsored by SGI. - v0.88 - 19991214 Richard Gooch - Removed kmod support. - Work sponsored by SGI. - v0.89 - 19991216 Richard Gooch - Improved debugging in . - Ensure dentries created by devfsd will be cleaned up. - Work sponsored by SGI. - v0.90 - 19991223 Richard Gooch - Created . - Work sponsored by SGI. - v0.91 - 20000203 Richard Gooch - Ported to kernel 2.3.42. - Removed . - Work sponsored by SGI. - v0.92 - 20000306 Richard Gooch - Added DEVFS_ FL_NO_PERSISTENCE flag. - Removed unnecessary call to in - . - Work sponsored by SGI. - v0.93 - 20000413 Richard Gooch - Set inode->i_size to correct size for symlinks. - 20000414 Richard Gooch - Only give lookup() method to directories to comply with new VFS - assumptions. - Work sponsored by SGI. - 20000415 Richard Gooch - Remove unnecessary tests in symlink methods. - Don't kill existing block ops in . - Work sponsored by SGI. - v0.94 - 20000424 Richard Gooch - Don't create missing directories in . - Work sponsored by SGI. - v0.95 - 20000430 Richard Gooch - Added CONFIG_DEVFS_MOUNT. - Work sponsored by SGI. - v0.96 - 20000608 Richard Gooch - Disabled multi-mount capability (use VFS bindings instead). - Work sponsored by SGI. - v0.97 - 20000610 Richard Gooch - Switched to FS_SINGLE to disable multi-mounts. - 20000612 Richard Gooch - Removed module support. - Removed multi-mount code. - Removed compatibility macros: VFS has changed too much. - Work sponsored by SGI. - v0.98 - 20000614 Richard Gooch - Merged devfs inode into devfs entry. - Work sponsored by SGI. - v0.99 - 20000619 Richard Gooch - Removed dead code in which used to call - . - Work sponsored by SGI. - v0.100 - 20000621 Richard Gooch - Changed interface to . - Work sponsored by SGI. - v0.101 - 20000622 Richard Gooch - Simplified interface to and . - Simplified interface to . - Work sponsored by SGI. - v0.102 - 20010519 Richard Gooch - Ensure terminates string for root entry. - Exported to modules. - 20010520 Richard Gooch - Make send events to devfsd. - Cleaned up option processing in . - 20010521 Richard Gooch - Fixed bugs in handling symlinks: could leak or cause Oops. - 20010522 Richard Gooch - Cleaned up directory handling by separating fops. - v0.103 - 20010601 Richard Gooch - Fixed handling of inverted options in . - v0.104 - 20010604 Richard Gooch - Adjusted to account for fix. - v0.105 - 20010617 Richard Gooch - Answered question posed by Al Viro and removed his comments. - Moved setting of registered flag after other fields are changed. - Fixed race between and . - Global VFS changes added bogus BKL to : removed. - Widened locking in and . - Replaced stack usage with kmalloc. - Simplified locking in and fixed memory leak. - v0.106 - 20010709 Richard Gooch - Removed broken devnum allocation and use . - Fixed old devnum leak by calling new . - v0.107 - 20010712 Richard Gooch - Fixed bug in which could hang boot process. - v0.108 - 20010730 Richard Gooch - Added DEVFSD_NOTIFY_DELETE event. - 20010801 Richard Gooch - Removed #include . - v0.109 - 20010807 Richard Gooch - Fixed inode table races by removing it and using - inode->u.generic_ip instead. - Moved into . - Moved into . - v0.110 - 20010808 Richard Gooch - Fixed race in for uni-processor. - v0.111 - 20010818 Richard Gooch - Removed remnant of multi-mount support in . - Removed unused DEVFS_FL_SHOW_UNREG flag. - v0.112 - 20010820 Richard Gooch - Removed nlink field from struct devfs_inode. - v0.113 - 20010823 Richard Gooch - Replaced BKL with global rwsem to protect symlink data (quick - and dirty hack). - v0.114 - 20010827 Richard Gooch - Replaced global rwsem for symlink with per-link refcount. - v0.115 - 20010919 Richard Gooch - Set inode->i_mapping->a_ops for block nodes in . - v0.116 - 20011008 Richard Gooch - Fixed overrun in by removing function (not needed). - 20011009 Richard Gooch - Fixed buffer underrun in . - 20011029 Richard Gooch - Fixed race in when setting event mask. - 20011114 Richard Gooch - First release of new locking code. - v1.0 - 20011117 Richard Gooch - Discard temporary buffer, now use "%s" for dentry names. - 20011118 Richard Gooch - Don't generate path in : use fake entry instead. - Use "existing" directory in <_devfs_make_parent_for_leaf>. - 20011122 Richard Gooch - Use slab cache rather than fixed buffer for devfsd events. - v1.1 - 20011125 Richard Gooch - Send DEVFSD_NOTIFY_REGISTERED events in . - 20011127 Richard Gooch - Fixed locking bug in due to typo. - Do not send CREATE, CHANGE, ASYNC_OPEN or DELETE events from - devfsd or children. - v1.2 - 20011202 Richard Gooch - Fixed bug in : was dereferencing freed pointer. - v1.3 - 20011203 Richard Gooch - Fixed bug in : was dereferencing freed pointer. - Added process group check for devfsd privileges. - v1.4 - 20011204 Richard Gooch - Use SLAB_ATOMIC in from . - v1.5 - 20011211 Richard Gooch - Return old entry in for 2.4.x kernels. - 20011212 Richard Gooch - Increment refcount on module in . - 20011215 Richard Gooch - Created and exported . - Increment refcount on module in . - Created . - v1.6 - 20011216 Richard Gooch - Added poisoning to . - Improved debugging messages. - v1.7 - 20011221 Richard Gooch - Corrected (made useful) debugging message in . - Moved in to - 20011224 Richard Gooch - Added magic number to guard against scribbling drivers. - 20011226 Richard Gooch - Only return old entry in if a directory. - Defined macros for error and debug messages. - v1.8 - 20020113 Richard Gooch - Fixed (rare, old) race in . - v1.9 - 20020120 Richard Gooch - Fixed deadlock bug in . - Tag VFS deletable in if handle ignored. - v1.10 - 20020129 Richard Gooch - Added KERN_* to remaining messages. - Cleaned up declaration of . - v1.11 - 20020219 Richard Gooch - Changed to allow later additions if not yet empty. - v1.12 - 20020406 Richard Gooch - Removed silently introduced calls to lock_kernel() and - unlock_kernel() due to recent VFS locking changes. BKL isn't - required in devfs. - v1.13 - 20020428 Richard Gooch - Removed 2.4.x compatibility code. - v1.14 - 20020510 Richard Gooch - Added BKL to because drivers still need it. - v1.15 - 20020512 Richard Gooch - Protected and - from changing directory contents. - v1.16 - 20020514 Richard Gooch - Minor cleanup of . - v1.17 - 20020721 Richard Gooch - Switched to ISO C structure field initialisers. - Switch to set_current_state() and move before add_wait_queue(). - 20020722 Richard Gooch - Fixed devfs entry leak in when *readdir fails. - v1.18 - 20020725 Richard Gooch - Created . - v1.19 - 20020728 Richard Gooch - Removed deprecated . - v1.20 - 20020820 Richard Gooch - Fixed module unload race in . - v1.21 - 20021013 Richard Gooch - Removed DEVFS_ FL_AUTO_OWNER. - Switched lingering structure field initialiser to ISO C. - Added locking when updating FCB flags. - v1.22 -*/ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include -#include -#include -#include - -#define DEVFS_VERSION "2004-01-31" - -#define DEVFS_NAME "devfs" - -#define FIRST_INODE 1 - -#define STRING_LENGTH 256 -#define FAKE_BLOCK_SIZE 1024 -#define POISON_PTR ( *(void **) poison_array ) -#define MAGIC_VALUE 0x327db823 - -#ifndef TRUE -# define TRUE 1 -# define FALSE 0 -#endif - -#define MODE_DIR (S_IFDIR | S_IWUSR | S_IRUGO | S_IXUGO) - -#define DEBUG_NONE 0x0000000 -#define DEBUG_MODULE_LOAD 0x0000001 -#define DEBUG_REGISTER 0x0000002 -#define DEBUG_UNREGISTER 0x0000004 -#define DEBUG_FREE 0x0000008 -#define DEBUG_SET_FLAGS 0x0000010 -#define DEBUG_S_READ 0x0000100 /* Break */ -#define DEBUG_I_LOOKUP 0x0001000 /* Break */ -#define DEBUG_I_CREATE 0x0002000 -#define DEBUG_I_GET 0x0004000 -#define DEBUG_I_CHANGE 0x0008000 -#define DEBUG_I_UNLINK 0x0010000 -#define DEBUG_I_RLINK 0x0020000 -#define DEBUG_I_FLINK 0x0040000 -#define DEBUG_I_MKNOD 0x0080000 -#define DEBUG_F_READDIR 0x0100000 /* Break */ -#define DEBUG_D_DELETE 0x1000000 /* Break */ -#define DEBUG_D_RELEASE 0x2000000 -#define DEBUG_D_IPUT 0x4000000 -#define DEBUG_ALL 0xfffffff -#define DEBUG_DISABLED DEBUG_NONE - -#define OPTION_NONE 0x00 -#define OPTION_MOUNT 0x01 - -#define PRINTK(format, args...) \ - {printk (KERN_ERR "%s" format, __FUNCTION__ , ## args);} - -#define OOPS(format, args...) \ - {printk (KERN_CRIT "%s" format, __FUNCTION__ , ## args); \ - printk ("Forcing Oops\n"); \ - BUG();} - -#ifdef CONFIG_DEVFS_DEBUG -# define VERIFY_ENTRY(de) \ - {if ((de) && (de)->magic_number != MAGIC_VALUE) \ - OOPS ("(%p): bad magic value: %x\n", (de), (de)->magic_number);} -# define WRITE_ENTRY_MAGIC(de,magic) (de)->magic_number = (magic) -# define DPRINTK(flag, format, args...) \ - {if (devfs_debug & flag) \ - printk (KERN_INFO "%s" format, __FUNCTION__ , ## args);} -#else -# define VERIFY_ENTRY(de) -# define WRITE_ENTRY_MAGIC(de,magic) -# define DPRINTK(flag, format, args...) -#endif - -typedef struct devfs_entry *devfs_handle_t; - -struct directory_type { - rwlock_t lock; /* Lock for searching(R)/updating(W) */ - struct devfs_entry *first; - struct devfs_entry *last; - unsigned char no_more_additions:1; -}; - -struct symlink_type { - unsigned int length; /* Not including the NULL-termimator */ - char *linkname; /* This is NULL-terminated */ -}; - -struct devfs_inode { /* This structure is for "persistent" inode storage */ - struct dentry *dentry; - struct timespec atime; - struct timespec mtime; - struct timespec ctime; - unsigned int ino; /* Inode number as seen in the VFS */ - uid_t uid; - gid_t gid; -}; - -struct devfs_entry { -#ifdef CONFIG_DEVFS_DEBUG - unsigned int magic_number; -#endif - void *info; - atomic_t refcount; /* When this drops to zero, it's unused */ - union { - struct directory_type dir; - dev_t dev; - struct symlink_type symlink; - const char *name; /* Only used for (mode == 0) */ - } u; - struct devfs_entry *prev; /* Previous entry in the parent directory */ - struct devfs_entry *next; /* Next entry in the parent directory */ - struct devfs_entry *parent; /* The parent directory */ - struct devfs_inode inode; - umode_t mode; - unsigned short namelen; /* I think 64k+ filenames are a way off... */ - unsigned char vfs:1; /* Whether the VFS may delete the entry */ - char name[1]; /* This is just a dummy: the allocated array - is bigger. This is NULL-terminated */ -}; - -/* The root of the device tree */ -static struct devfs_entry *root_entry; - -struct devfsd_buf_entry { - struct devfs_entry *de; /* The name is generated with this */ - unsigned short type; /* The type of event */ - umode_t mode; - uid_t uid; - gid_t gid; - struct devfsd_buf_entry *next; -}; - -struct fs_info { /* This structure is for the mounted devfs */ - struct super_block *sb; - spinlock_t devfsd_buffer_lock; /* Lock when inserting/deleting events */ - struct devfsd_buf_entry *devfsd_first_event; - struct devfsd_buf_entry *devfsd_last_event; - volatile int devfsd_sleeping; - volatile struct task_struct *devfsd_task; - volatile pid_t devfsd_pgrp; - volatile struct file *devfsd_file; - struct devfsd_notify_struct *devfsd_info; - volatile unsigned long devfsd_event_mask; - atomic_t devfsd_overrun_count; - wait_queue_head_t devfsd_wait_queue; /* Wake devfsd on input */ - wait_queue_head_t revalidate_wait_queue; /* Wake when devfsd sleeps */ -}; - -static struct fs_info fs_info = {.devfsd_buffer_lock = SPIN_LOCK_UNLOCKED }; -static kmem_cache_t *devfsd_buf_cache; -#ifdef CONFIG_DEVFS_DEBUG -static unsigned int devfs_debug_init __initdata = DEBUG_NONE; -static unsigned int devfs_debug = DEBUG_NONE; -static DEFINE_SPINLOCK(stat_lock); -static unsigned int stat_num_entries; -static unsigned int stat_num_bytes; -#endif -static unsigned char poison_array[8] = - { 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a, 0x5a }; - -#ifdef CONFIG_DEVFS_MOUNT -static unsigned int boot_options = OPTION_MOUNT; -#else -static unsigned int boot_options = OPTION_NONE; -#endif - -/* Forward function declarations */ -static devfs_handle_t _devfs_walk_path(struct devfs_entry *dir, - const char *name, int namelen, - int traverse_symlink); -static ssize_t devfsd_read(struct file *file, char __user *buf, size_t len, - loff_t * ppos); -static int devfsd_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg); -static int devfsd_close(struct inode *inode, struct file *file); -#ifdef CONFIG_DEVFS_DEBUG -static ssize_t stat_read(struct file *file, char __user *buf, size_t len, - loff_t * ppos); -static const struct file_operations stat_fops = { - .open = nonseekable_open, - .read = stat_read, -}; -#endif - -/* Devfs daemon file operations */ -static const struct file_operations devfsd_fops = { - .open = nonseekable_open, - .read = devfsd_read, - .ioctl = devfsd_ioctl, - .release = devfsd_close, -}; - -/* Support functions follow */ - -/** - * devfs_get - Get a reference to a devfs entry. - * @de: The devfs entry. - */ - -static struct devfs_entry *devfs_get(struct devfs_entry *de) -{ - VERIFY_ENTRY(de); - if (de) - atomic_inc(&de->refcount); - return de; -} /* End Function devfs_get */ - -/** - * devfs_put - Put (release) a reference to a devfs entry. - * @de: The handle to the devfs entry. - */ - -static void devfs_put(devfs_handle_t de) -{ - if (!de) - return; - VERIFY_ENTRY(de); - if (de->info == POISON_PTR) - OOPS("(%p): poisoned pointer\n", de); - if (!atomic_dec_and_test(&de->refcount)) - return; - if (de == root_entry) - OOPS("(%p): root entry being freed\n", de); - DPRINTK(DEBUG_FREE, "(%s): de: %p, parent: %p \"%s\"\n", - de->name, de, de->parent, - de->parent ? de->parent->name : "no parent"); - if (S_ISLNK(de->mode)) - kfree(de->u.symlink.linkname); - WRITE_ENTRY_MAGIC(de, 0); -#ifdef CONFIG_DEVFS_DEBUG - spin_lock(&stat_lock); - --stat_num_entries; - stat_num_bytes -= sizeof *de + de->namelen; - if (S_ISLNK(de->mode)) - stat_num_bytes -= de->u.symlink.length + 1; - spin_unlock(&stat_lock); -#endif - de->info = POISON_PTR; - kfree(de); -} /* End Function devfs_put */ - -/** - * _devfs_search_dir - Search for a devfs entry in a directory. - * @dir: The directory to search. - * @name: The name of the entry to search for. - * @namelen: The number of characters in @name. - * - * Search for a devfs entry in a directory and returns a pointer to the entry - * on success, else %NULL. The directory must be locked already. - * An implicit devfs_get() is performed on the returned entry. - */ - -static struct devfs_entry *_devfs_search_dir(struct devfs_entry *dir, - const char *name, - unsigned int namelen) -{ - struct devfs_entry *curr; - - if (!S_ISDIR(dir->mode)) { - PRINTK("(%s): not a directory\n", dir->name); - return NULL; - } - for (curr = dir->u.dir.first; curr != NULL; curr = curr->next) { - if (curr->namelen != namelen) - continue; - if (memcmp(curr->name, name, namelen) == 0) - break; - /* Not found: try the next one */ - } - return devfs_get(curr); -} /* End Function _devfs_search_dir */ - -/** - * _devfs_alloc_entry - Allocate a devfs entry. - * @name: the name of the entry - * @namelen: the number of characters in @name - * @mode: the mode for the entry - * - * Allocate a devfs entry and returns a pointer to the entry on success, else - * %NULL. - */ - -static struct devfs_entry *_devfs_alloc_entry(const char *name, - unsigned int namelen, - umode_t mode) -{ - struct devfs_entry *new; - static unsigned long inode_counter = FIRST_INODE; - static DEFINE_SPINLOCK(counter_lock); - - if (name && (namelen < 1)) - namelen = strlen(name); - if ((new = kmalloc(sizeof *new + namelen, GFP_KERNEL)) == NULL) - return NULL; - memset(new, 0, sizeof *new + namelen); /* Will set '\0' on name */ - new->mode = mode; - if (S_ISDIR(mode)) - rwlock_init(&new->u.dir.lock); - atomic_set(&new->refcount, 1); - spin_lock(&counter_lock); - new->inode.ino = inode_counter++; - spin_unlock(&counter_lock); - if (name) - memcpy(new->name, name, namelen); - new->namelen = namelen; - WRITE_ENTRY_MAGIC(new, MAGIC_VALUE); -#ifdef CONFIG_DEVFS_DEBUG - spin_lock(&stat_lock); - ++stat_num_entries; - stat_num_bytes += sizeof *new + namelen; - spin_unlock(&stat_lock); -#endif - return new; -} /* End Function _devfs_alloc_entry */ - -/** - * _devfs_append_entry - Append a devfs entry to a directory's child list. - * @dir: The directory to add to. - * @de: The devfs entry to append. - * @old_de: If an existing entry exists, it will be written here. This may - * be %NULL. An implicit devfs_get() is performed on this entry. - * - * Append a devfs entry to a directory's list of children, checking first to - * see if an entry of the same name exists. The directory will be locked. - * The value 0 is returned on success, else a negative error code. - * On failure, an implicit devfs_put() is performed on %de. - */ - -static int _devfs_append_entry(devfs_handle_t dir, devfs_handle_t de, - devfs_handle_t * old_de) -{ - int retval; - - if (old_de) - *old_de = NULL; - if (!S_ISDIR(dir->mode)) { - PRINTK("(%s): dir: \"%s\" is not a directory\n", de->name, - dir->name); - devfs_put(de); - return -ENOTDIR; - } - write_lock(&dir->u.dir.lock); - if (dir->u.dir.no_more_additions) - retval = -ENOENT; - else { - struct devfs_entry *old; - - old = _devfs_search_dir(dir, de->name, de->namelen); - if (old_de) - *old_de = old; - else - devfs_put(old); - if (old == NULL) { - de->parent = dir; - de->prev = dir->u.dir.last; - /* Append to the directory's list of children */ - if (dir->u.dir.first == NULL) - dir->u.dir.first = de; - else - dir->u.dir.last->next = de; - dir->u.dir.last = de; - retval = 0; - } else - retval = -EEXIST; - } - write_unlock(&dir->u.dir.lock); - if (retval) - devfs_put(de); - return retval; -} /* End Function _devfs_append_entry */ - -/** - * _devfs_get_root_entry - Get the root devfs entry. - * - * Returns the root devfs entry on success, else %NULL. - * - * TODO it must be called asynchronously due to the fact - * that devfs is initialized relatively late. Proper way - * is to remove module_init from init_devfs_fs and manually - * call it early enough during system init - */ - -static struct devfs_entry *_devfs_get_root_entry(void) -{ - struct devfs_entry *new; - static DEFINE_SPINLOCK(root_lock); - - if (root_entry) - return root_entry; - - new = _devfs_alloc_entry(NULL, 0, MODE_DIR); - if (new == NULL) - return NULL; - - spin_lock(&root_lock); - if (root_entry) { - spin_unlock(&root_lock); - devfs_put(new); - return root_entry; - } - root_entry = new; - spin_unlock(&root_lock); - - return root_entry; -} /* End Function _devfs_get_root_entry */ - -/** - * _devfs_descend - Descend down a tree using the next component name. - * @dir: The directory to search. - * @name: The component name to search for. - * @namelen: The length of %name. - * @next_pos: The position of the next '/' or '\0' is written here. - * - * Descend into a directory, searching for a component. This function forms - * the core of a tree-walking algorithm. The directory will be locked. - * The devfs entry corresponding to the component is returned. If there is - * no matching entry, %NULL is returned. - * An implicit devfs_get() is performed on the returned entry. - */ - -static struct devfs_entry *_devfs_descend(struct devfs_entry *dir, - const char *name, int namelen, - int *next_pos) -{ - const char *stop, *ptr; - struct devfs_entry *entry; - - if ((namelen >= 3) && (strncmp(name, "../", 3) == 0)) { /* Special-case going to parent directory */ - *next_pos = 3; - return devfs_get(dir->parent); - } - stop = name + namelen; - /* Search for a possible '/' */ - for (ptr = name; (ptr < stop) && (*ptr != '/'); ++ptr) ; - *next_pos = ptr - name; - read_lock(&dir->u.dir.lock); - entry = _devfs_search_dir(dir, name, *next_pos); - read_unlock(&dir->u.dir.lock); - return entry; -} /* End Function _devfs_descend */ - -static devfs_handle_t _devfs_make_parent_for_leaf(struct devfs_entry *dir, - const char *name, - int namelen, int *leaf_pos) -{ - int next_pos = 0; - - if (dir == NULL) - dir = _devfs_get_root_entry(); - if (dir == NULL) - return NULL; - devfs_get(dir); - /* Search for possible trailing component and ignore it */ - for (--namelen; (namelen > 0) && (name[namelen] != '/'); --namelen) ; - *leaf_pos = (name[namelen] == '/') ? (namelen + 1) : 0; - for (; namelen > 0; name += next_pos, namelen -= next_pos) { - struct devfs_entry *de, *old = NULL; - - if ((de = - _devfs_descend(dir, name, namelen, &next_pos)) == NULL) { - de = _devfs_alloc_entry(name, next_pos, MODE_DIR); - devfs_get(de); - if (!de || _devfs_append_entry(dir, de, &old)) { - devfs_put(de); - if (!old || !S_ISDIR(old->mode)) { - devfs_put(old); - devfs_put(dir); - return NULL; - } - de = old; /* Use the existing directory */ - } - } - if (de == dir->parent) { - devfs_put(dir); - devfs_put(de); - return NULL; - } - devfs_put(dir); - dir = de; - if (name[next_pos] == '/') - ++next_pos; - } - return dir; -} /* End Function _devfs_make_parent_for_leaf */ - -static devfs_handle_t _devfs_prepare_leaf(devfs_handle_t * dir, - const char *name, umode_t mode) -{ - int namelen, leaf_pos; - struct devfs_entry *de; - - namelen = strlen(name); - if ((*dir = _devfs_make_parent_for_leaf(*dir, name, namelen, - &leaf_pos)) == NULL) { - PRINTK("(%s): could not create parent path\n", name); - return NULL; - } - if ((de = _devfs_alloc_entry(name + leaf_pos, namelen - leaf_pos, mode)) - == NULL) { - PRINTK("(%s): could not allocate entry\n", name); - devfs_put(*dir); - return NULL; - } - return de; -} /* End Function _devfs_prepare_leaf */ - -static devfs_handle_t _devfs_walk_path(struct devfs_entry *dir, - const char *name, int namelen, - int traverse_symlink) -{ - int next_pos = 0; - - if (dir == NULL) - dir = _devfs_get_root_entry(); - if (dir == NULL) - return NULL; - devfs_get(dir); - for (; namelen > 0; name += next_pos, namelen -= next_pos) { - struct devfs_entry *de, *link; - - if (!S_ISDIR(dir->mode)) { - devfs_put(dir); - return NULL; - } - - if ((de = - _devfs_descend(dir, name, namelen, &next_pos)) == NULL) { - devfs_put(dir); - return NULL; - } - if (S_ISLNK(de->mode) && traverse_symlink) { /* Need to follow the link: this is a stack chomper */ - /* FIXME what if it puts outside of mounted tree? */ - link = _devfs_walk_path(dir, de->u.symlink.linkname, - de->u.symlink.length, TRUE); - devfs_put(de); - if (!link) { - devfs_put(dir); - return NULL; - } - de = link; - } - devfs_put(dir); - dir = de; - if (name[next_pos] == '/') - ++next_pos; - } - return dir; -} /* End Function _devfs_walk_path */ - -/** - * _devfs_find_entry - Find a devfs entry. - * @dir: The handle to the parent devfs directory entry. If this is %NULL the - * name is relative to the root of the devfs. - * @name: The name of the entry. This may be %NULL. - * @traverse_symlink: If %TRUE then symbolic links are traversed. - * - * Returns the devfs_entry pointer on success, else %NULL. An implicit - * devfs_get() is performed. - */ - -static struct devfs_entry *_devfs_find_entry(devfs_handle_t dir, - const char *name, - int traverse_symlink) -{ - unsigned int namelen = strlen(name); - - if (name[0] == '/') { - /* Skip leading pathname component */ - if (namelen < 2) { - PRINTK("(%s): too short\n", name); - return NULL; - } - for (++name, --namelen; (*name != '/') && (namelen > 0); - ++name, --namelen) ; - if (namelen < 2) { - PRINTK("(%s): too short\n", name); - return NULL; - } - ++name; - --namelen; - } - return _devfs_walk_path(dir, name, namelen, traverse_symlink); -} /* End Function _devfs_find_entry */ - -static struct devfs_entry *get_devfs_entry_from_vfs_inode(struct inode *inode) -{ - if (inode == NULL) - return NULL; - VERIFY_ENTRY((struct devfs_entry *)inode->u.generic_ip); - return inode->u.generic_ip; -} /* End Function get_devfs_entry_from_vfs_inode */ - -/** - * free_dentry - Free the dentry for a device entry and invalidate inode. - * @de: The entry. - * - * This must only be called after the entry has been unhooked from its - * parent directory. - */ - -static void free_dentry(struct devfs_entry *de) -{ - struct dentry *dentry = de->inode.dentry; - - if (!dentry) - return; - spin_lock(&dcache_lock); - dget_locked(dentry); - spin_unlock(&dcache_lock); - /* Forcefully remove the inode */ - if (dentry->d_inode != NULL) - dentry->d_inode->i_nlink = 0; - d_drop(dentry); - dput(dentry); -} /* End Function free_dentry */ - -/** - * is_devfsd_or_child - Test if the current process is devfsd or one of its children. - * @fs_info: The filesystem information. - * - * Returns %TRUE if devfsd or child, else %FALSE. - */ - -static int is_devfsd_or_child(struct fs_info *fs_info) -{ - struct task_struct *p = current; - - if (p == fs_info->devfsd_task) - return (TRUE); - if (process_group(p) == fs_info->devfsd_pgrp) - return (TRUE); - read_lock(&tasklist_lock); - for (; p != &init_task; p = p->real_parent) { - if (p == fs_info->devfsd_task) { - read_unlock(&tasklist_lock); - return (TRUE); - } - } - read_unlock(&tasklist_lock); - return (FALSE); -} /* End Function is_devfsd_or_child */ - -/** - * devfsd_queue_empty - Test if devfsd has work pending in its event queue. - * @fs_info: The filesystem information. - * - * Returns %TRUE if the queue is empty, else %FALSE. - */ - -static inline int devfsd_queue_empty(struct fs_info *fs_info) -{ - return (fs_info->devfsd_last_event) ? FALSE : TRUE; -} /* End Function devfsd_queue_empty */ - -/** - * wait_for_devfsd_finished - Wait for devfsd to finish processing its event queue. - * @fs_info: The filesystem information. - * - * Returns %TRUE if no more waiting will be required, else %FALSE. - */ - -static int wait_for_devfsd_finished(struct fs_info *fs_info) -{ - DECLARE_WAITQUEUE(wait, current); - - if (fs_info->devfsd_task == NULL) - return (TRUE); - if (devfsd_queue_empty(fs_info) && fs_info->devfsd_sleeping) - return TRUE; - if (is_devfsd_or_child(fs_info)) - return (FALSE); - set_current_state(TASK_UNINTERRUPTIBLE); - add_wait_queue(&fs_info->revalidate_wait_queue, &wait); - if (!devfsd_queue_empty(fs_info) || !fs_info->devfsd_sleeping) - if (fs_info->devfsd_task) - schedule(); - remove_wait_queue(&fs_info->revalidate_wait_queue, &wait); - __set_current_state(TASK_RUNNING); - return (TRUE); -} /* End Function wait_for_devfsd_finished */ - -/** - * devfsd_notify_de - Notify the devfsd daemon of a change. - * @de: The devfs entry that has changed. This and all parent entries will - * have their reference counts incremented if the event was queued. - * @type: The type of change. - * @mode: The mode of the entry. - * @uid: The user ID. - * @gid: The group ID. - * @fs_info: The filesystem info. - * - * Returns %TRUE if an event was queued and devfsd woken up, else %FALSE. - */ - -static int devfsd_notify_de(struct devfs_entry *de, - unsigned short type, umode_t mode, - uid_t uid, gid_t gid, struct fs_info *fs_info) -{ - struct devfsd_buf_entry *entry; - struct devfs_entry *curr; - - if (!(fs_info->devfsd_event_mask & (1 << type))) - return (FALSE); - if ((entry = kmem_cache_alloc(devfsd_buf_cache, SLAB_KERNEL)) == NULL) { - atomic_inc(&fs_info->devfsd_overrun_count); - return (FALSE); - } - for (curr = de; curr != NULL; curr = curr->parent) - devfs_get(curr); - entry->de = de; - entry->type = type; - entry->mode = mode; - entry->uid = uid; - entry->gid = gid; - entry->next = NULL; - spin_lock(&fs_info->devfsd_buffer_lock); - if (!fs_info->devfsd_first_event) - fs_info->devfsd_first_event = entry; - if (fs_info->devfsd_last_event) - fs_info->devfsd_last_event->next = entry; - fs_info->devfsd_last_event = entry; - spin_unlock(&fs_info->devfsd_buffer_lock); - wake_up_interruptible(&fs_info->devfsd_wait_queue); - return (TRUE); -} /* End Function devfsd_notify_de */ - -/** - * devfsd_notify - Notify the devfsd daemon of a change. - * @de: The devfs entry that has changed. - * @type: The type of change event. - * @wait: If TRUE, the function waits for the daemon to finish processing - * the event. - */ - -static void devfsd_notify(struct devfs_entry *de, unsigned short type) -{ - devfsd_notify_de(de, type, de->mode, current->euid, - current->egid, &fs_info); -} - -static int devfs_mk_dev(dev_t dev, umode_t mode, const char *fmt, va_list args) -{ - struct devfs_entry *dir = NULL, *de; - char buf[64]; - int error, n; - - n = vsnprintf(buf, sizeof(buf), fmt, args); - if (n >= sizeof(buf) || !buf[0]) { - printk(KERN_WARNING "%s: invalid format string %s\n", - __FUNCTION__, fmt); - return -EINVAL; - } - - de = _devfs_prepare_leaf(&dir, buf, mode); - if (!de) { - printk(KERN_WARNING "%s: could not prepare leaf for %s\n", - __FUNCTION__, buf); - return -ENOMEM; /* could be more accurate... */ - } - - de->u.dev = dev; - - error = _devfs_append_entry(dir, de, NULL); - if (error) { - printk(KERN_WARNING "%s: could not append to parent for %s\n", - __FUNCTION__, buf); - goto out; - } - - devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED); - out: - devfs_put(dir); - return error; -} - -int devfs_mk_bdev(dev_t dev, umode_t mode, const char *fmt, ...) -{ - va_list args; - - if (!S_ISBLK(mode)) { - printk(KERN_WARNING "%s: invalide mode (%u) for %s\n", - __FUNCTION__, mode, fmt); - return -EINVAL; - } - - va_start(args, fmt); - return devfs_mk_dev(dev, mode, fmt, args); -} - -EXPORT_SYMBOL(devfs_mk_bdev); - -int devfs_mk_cdev(dev_t dev, umode_t mode, const char *fmt, ...) -{ - va_list args; - - if (!S_ISCHR(mode)) { - printk(KERN_WARNING "%s: invalide mode (%u) for %s\n", - __FUNCTION__, mode, fmt); - return -EINVAL; - } - - va_start(args, fmt); - return devfs_mk_dev(dev, mode, fmt, args); -} - -EXPORT_SYMBOL(devfs_mk_cdev); - -/** - * _devfs_unhook - Unhook a device entry from its parents list - * @de: The entry to unhook. - * - * Returns %TRUE if the entry was unhooked, else %FALSE if it was - * previously unhooked. - * The caller must have a write lock on the parent directory. - */ - -static int _devfs_unhook(struct devfs_entry *de) -{ - struct devfs_entry *parent; - - if (!de || (de->prev == de)) - return FALSE; - parent = de->parent; - if (de->prev == NULL) - parent->u.dir.first = de->next; - else - de->prev->next = de->next; - if (de->next == NULL) - parent->u.dir.last = de->prev; - else - de->next->prev = de->prev; - de->prev = de; /* Indicate we're unhooked */ - de->next = NULL; /* Force early termination for */ - return TRUE; -} /* End Function _devfs_unhook */ - -/** - * _devfs_unregister - Unregister a device entry from its parent. - * @dir: The parent directory. - * @de: The entry to unregister. - * - * The caller must have a write lock on the parent directory, which is - * unlocked by this function. - */ - -static void _devfs_unregister(struct devfs_entry *dir, struct devfs_entry *de) -{ - int unhooked = _devfs_unhook(de); - - write_unlock(&dir->u.dir.lock); - if (!unhooked) - return; - devfs_get(dir); - devfsd_notify(de, DEVFSD_NOTIFY_UNREGISTERED); - free_dentry(de); - devfs_put(dir); - if (!S_ISDIR(de->mode)) - return; - while (TRUE) { /* Recursively unregister: this is a stack chomper */ - struct devfs_entry *child; - - write_lock(&de->u.dir.lock); - de->u.dir.no_more_additions = TRUE; - child = de->u.dir.first; - VERIFY_ENTRY(child); - _devfs_unregister(de, child); - if (!child) - break; - DPRINTK(DEBUG_UNREGISTER, "(%s): child: %p refcount: %d\n", - child->name, child, atomic_read(&child->refcount)); - devfs_put(child); - } -} /* End Function _devfs_unregister */ - -static int devfs_do_symlink(devfs_handle_t dir, const char *name, - const char *link, devfs_handle_t * handle) -{ - int err; - unsigned int linklength; - char *newlink; - struct devfs_entry *de; - - if (handle != NULL) - *handle = NULL; - if (name == NULL) { - PRINTK("(): NULL name pointer\n"); - return -EINVAL; - } - if (link == NULL) { - PRINTK("(%s): NULL link pointer\n", name); - return -EINVAL; - } - linklength = strlen(link); - if ((newlink = kmalloc(linklength + 1, GFP_KERNEL)) == NULL) - return -ENOMEM; - memcpy(newlink, link, linklength); - newlink[linklength] = '\0'; - if ((de = _devfs_prepare_leaf(&dir, name, S_IFLNK | S_IRUGO | S_IXUGO)) - == NULL) { - PRINTK("(%s): could not prepare leaf\n", name); - kfree(newlink); - return -ENOTDIR; - } - de->info = NULL; - de->u.symlink.linkname = newlink; - de->u.symlink.length = linklength; - if ((err = _devfs_append_entry(dir, de, NULL)) != 0) { - PRINTK("(%s): could not append to parent, err: %d\n", name, - err); - devfs_put(dir); - return err; - } - devfs_put(dir); -#ifdef CONFIG_DEVFS_DEBUG - spin_lock(&stat_lock); - stat_num_bytes += linklength + 1; - spin_unlock(&stat_lock); -#endif - if (handle != NULL) - *handle = de; - return 0; -} /* End Function devfs_do_symlink */ - -/** - * devfs_mk_symlink Create a symbolic link in the devfs namespace. - * @from: The name of the entry. - * @to: Name of the destination - * - * Returns 0 on success, else a negative error code is returned. - */ - -int devfs_mk_symlink(const char *from, const char *to) -{ - devfs_handle_t de; - int err; - - err = devfs_do_symlink(NULL, from, to, &de); - if (!err) { - de->vfs = TRUE; - devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED); - } - - return err; -} - -/** - * devfs_mk_dir - Create a directory in the devfs namespace. - * new name is relative to the root of the devfs. - * @fmt: The name of the entry. - * - * Use of this function is optional. The devfs_register() function - * will automatically create intermediate directories as needed. This function - * is provided for efficiency reasons, as it provides a handle to a directory. - * On failure %NULL is returned. - */ - -int devfs_mk_dir(const char *fmt, ...) -{ - struct devfs_entry *dir = NULL, *de = NULL, *old; - char buf[64]; - va_list args; - int error, n; - - va_start(args, fmt); - n = vsnprintf(buf, 64, fmt, args); - if (n >= 64 || !buf[0]) { - printk(KERN_WARNING "%s: invalid argument.", __FUNCTION__); - return -EINVAL; - } - - de = _devfs_prepare_leaf(&dir, buf, MODE_DIR); - if (!de) { - PRINTK("(%s): could not prepare leaf\n", buf); - return -EINVAL; - } - - error = _devfs_append_entry(dir, de, &old); - if (error == -EEXIST && S_ISDIR(old->mode)) { - /* - * devfs_mk_dir() of an already-existing directory will - * return success. - */ - error = 0; - goto out_put; - } else if (error) { - PRINTK("(%s): could not append to dir: %p \"%s\"\n", - buf, dir, dir->name); - devfs_put(old); - goto out_put; - } - - devfsd_notify(de, DEVFSD_NOTIFY_REGISTERED); - - out_put: - devfs_put(dir); - return error; -} - -void devfs_remove(const char *fmt, ...) -{ - char buf[64]; - va_list args; - int n; - - va_start(args, fmt); - n = vsnprintf(buf, sizeof(buf), fmt, args); - if (n < sizeof(buf) && buf[0]) { - devfs_handle_t de = _devfs_find_entry(NULL, buf, 0); - - if (!de) { - printk(KERN_ERR "%s: %s not found, cannot remove\n", - __FUNCTION__, buf); - dump_stack(); - return; - } - - write_lock(&de->parent->u.dir.lock); - _devfs_unregister(de->parent, de); - devfs_put(de); - devfs_put(de); - } -} - -/** - * devfs_generate_path - Generate a pathname for an entry, relative to the devfs root. - * @de: The devfs entry. - * @path: The buffer to write the pathname to. The pathname and '\0' - * terminator will be written at the end of the buffer. - * @buflen: The length of the buffer. - * - * Returns the offset in the buffer where the pathname starts on success, - * else a negative error code. - */ - -static int devfs_generate_path(devfs_handle_t de, char *path, int buflen) -{ - int pos; -#define NAMEOF(de) ( (de)->mode ? (de)->name : (de)->u.name ) - - if (de == NULL) - return -EINVAL; - VERIFY_ENTRY(de); - if (de->namelen >= buflen) - return -ENAMETOOLONG; /* Must be first */ - path[buflen - 1] = '\0'; - if (de->parent == NULL) - return buflen - 1; /* Don't prepend root */ - pos = buflen - de->namelen - 1; - memcpy(path + pos, NAMEOF(de), de->namelen); - for (de = de->parent; de->parent != NULL; de = de->parent) { - if (pos - de->namelen - 1 < 0) - return -ENAMETOOLONG; - path[--pos] = '/'; - pos -= de->namelen; - memcpy(path + pos, NAMEOF(de), de->namelen); - } - return pos; -} /* End Function devfs_generate_path */ - -/** - * devfs_setup - Process kernel boot options. - * @str: The boot options after the "devfs=". - */ - -static int __init devfs_setup(char *str) -{ - static struct { - char *name; - unsigned int mask; - unsigned int *opt; - } devfs_options_tab[] __initdata = { -#ifdef CONFIG_DEVFS_DEBUG - { - "dall", DEBUG_ALL, &devfs_debug_init}, { - "dmod", DEBUG_MODULE_LOAD, &devfs_debug_init}, { - "dreg", DEBUG_REGISTER, &devfs_debug_init}, { - "dunreg", DEBUG_UNREGISTER, &devfs_debug_init}, { - "dfree", DEBUG_FREE, &devfs_debug_init}, { - "diget", DEBUG_I_GET, &devfs_debug_init}, { - "dchange", DEBUG_SET_FLAGS, &devfs_debug_init}, { - "dsread", DEBUG_S_READ, &devfs_debug_init}, { - "dichange", DEBUG_I_CHANGE, &devfs_debug_init}, { - "dimknod", DEBUG_I_MKNOD, &devfs_debug_init}, { - "dilookup", DEBUG_I_LOOKUP, &devfs_debug_init}, { - "diunlink", DEBUG_I_UNLINK, &devfs_debug_init}, -#endif /* CONFIG_DEVFS_DEBUG */ - { - "mount", OPTION_MOUNT, &boot_options}, { - NULL, 0, NULL} - }; - - while ((*str != '\0') && !isspace(*str)) { - int i, found = 0, invert = 0; - - if (strncmp(str, "no", 2) == 0) { - invert = 1; - str += 2; - } - for (i = 0; devfs_options_tab[i].name != NULL; i++) { - int len = strlen(devfs_options_tab[i].name); - - if (strncmp(str, devfs_options_tab[i].name, len) == 0) { - if (invert) - *devfs_options_tab[i].opt &= - ~devfs_options_tab[i].mask; - else - *devfs_options_tab[i].opt |= - devfs_options_tab[i].mask; - str += len; - found = 1; - break; - } - } - if (!found) - return 0; /* No match */ - if (*str != ',') - return 0; /* No more options */ - ++str; - } - return 1; -} /* End Function devfs_setup */ - -__setup("devfs=", devfs_setup); - -EXPORT_SYMBOL(devfs_mk_dir); -EXPORT_SYMBOL(devfs_remove); - -/** - * try_modload - Notify devfsd of an inode lookup by a non-devfsd process. - * @parent: The parent devfs entry. - * @fs_info: The filesystem info. - * @name: The device name. - * @namelen: The number of characters in @name. - * @buf: A working area that will be used. This must not go out of scope - * until devfsd is idle again. - * - * Returns 0 on success (event was queued), else a negative error code. - */ - -static int try_modload(struct devfs_entry *parent, struct fs_info *fs_info, - const char *name, unsigned namelen, - struct devfs_entry *buf) -{ - if (!(fs_info->devfsd_event_mask & (1 << DEVFSD_NOTIFY_LOOKUP))) - return -ENOENT; - if (is_devfsd_or_child(fs_info)) - return -ENOENT; - memset(buf, 0, sizeof *buf); - atomic_set(&buf->refcount, 1); - buf->parent = parent; - buf->namelen = namelen; - buf->u.name = name; - WRITE_ENTRY_MAGIC(buf, MAGIC_VALUE); - if (!devfsd_notify_de(buf, DEVFSD_NOTIFY_LOOKUP, 0, - current->euid, current->egid, fs_info)) - return -ENOENT; - /* Possible success: event has been queued */ - return 0; -} /* End Function try_modload */ - -/* Superblock operations follow */ - -static struct inode_operations devfs_iops; -static struct inode_operations devfs_dir_iops; -static const struct file_operations devfs_fops; -static const struct file_operations devfs_dir_fops; -static struct inode_operations devfs_symlink_iops; - -static int devfs_notify_change(struct dentry *dentry, struct iattr *iattr) -{ - int retval; - struct devfs_entry *de; - struct inode *inode = dentry->d_inode; - struct fs_info *fs_info = inode->i_sb->s_fs_info; - - de = get_devfs_entry_from_vfs_inode(inode); - if (de == NULL) - return -ENODEV; - retval = inode_change_ok(inode, iattr); - if (retval != 0) - return retval; - retval = inode_setattr(inode, iattr); - if (retval != 0) - return retval; - DPRINTK(DEBUG_I_CHANGE, "(%d): VFS inode: %p devfs_entry: %p\n", - (int)inode->i_ino, inode, de); - DPRINTK(DEBUG_I_CHANGE, "(): mode: 0%o uid: %d gid: %d\n", - (int)inode->i_mode, (int)inode->i_uid, (int)inode->i_gid); - /* Inode is not on hash chains, thus must save permissions here rather - than in a write_inode() method */ - de->mode = inode->i_mode; - de->inode.uid = inode->i_uid; - de->inode.gid = inode->i_gid; - de->inode.atime = inode->i_atime; - de->inode.mtime = inode->i_mtime; - de->inode.ctime = inode->i_ctime; - if ((iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) && - !is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_CHANGE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - return 0; -} /* End Function devfs_notify_change */ - -static struct super_operations devfs_sops = { - .drop_inode = generic_delete_inode, - .statfs = simple_statfs, -}; - -/** - * _devfs_get_vfs_inode - Get a VFS inode. - * @sb: The super block. - * @de: The devfs inode. - * @dentry: The dentry to register with the devfs inode. - * - * Returns the inode on success, else %NULL. An implicit devfs_get() is - * performed if the inode is created. - */ - -static struct inode *_devfs_get_vfs_inode(struct super_block *sb, - struct devfs_entry *de, - struct dentry *dentry) -{ - struct inode *inode; - - if (de->prev == de) - return NULL; /* Quick check to see if unhooked */ - if ((inode = new_inode(sb)) == NULL) { - PRINTK("(%s): new_inode() failed, de: %p\n", de->name, de); - return NULL; - } - if (de->parent) { - read_lock(&de->parent->u.dir.lock); - if (de->prev != de) - de->inode.dentry = dentry; /* Not unhooked */ - read_unlock(&de->parent->u.dir.lock); - } else - de->inode.dentry = dentry; /* Root: no locking needed */ - if (de->inode.dentry != dentry) { /* Must have been unhooked */ - iput(inode); - return NULL; - } - /* FIXME where is devfs_put? */ - inode->u.generic_ip = devfs_get(de); - inode->i_ino = de->inode.ino; - DPRINTK(DEBUG_I_GET, "(%d): VFS inode: %p devfs_entry: %p\n", - (int)inode->i_ino, inode, de); - inode->i_blocks = 0; - inode->i_blksize = FAKE_BLOCK_SIZE; - inode->i_op = &devfs_iops; - inode->i_mode = de->mode; - if (S_ISDIR(de->mode)) { - inode->i_op = &devfs_dir_iops; - inode->i_fop = &devfs_dir_fops; - } else if (S_ISLNK(de->mode)) { - inode->i_op = &devfs_symlink_iops; - inode->i_size = de->u.symlink.length; - } else if (S_ISCHR(de->mode) || S_ISBLK(de->mode)) { - init_special_inode(inode, de->mode, de->u.dev); - } else if (S_ISFIFO(de->mode) || S_ISSOCK(de->mode)) { - init_special_inode(inode, de->mode, 0); - } else { - PRINTK("(%s): unknown mode %o de: %p\n", - de->name, de->mode, de); - iput(inode); - devfs_put(de); - return NULL; - } - - inode->i_uid = de->inode.uid; - inode->i_gid = de->inode.gid; - inode->i_atime = de->inode.atime; - inode->i_mtime = de->inode.mtime; - inode->i_ctime = de->inode.ctime; - DPRINTK(DEBUG_I_GET, "(): mode: 0%o uid: %d gid: %d\n", - (int)inode->i_mode, (int)inode->i_uid, (int)inode->i_gid); - return inode; -} /* End Function _devfs_get_vfs_inode */ - -/* File operations for device entries follow */ - -static int devfs_readdir(struct file *file, void *dirent, filldir_t filldir) -{ - int err, count; - int stored = 0; - struct fs_info *fs_info; - struct devfs_entry *parent, *de, *next = NULL; - struct inode *inode = file->f_dentry->d_inode; - - fs_info = inode->i_sb->s_fs_info; - parent = get_devfs_entry_from_vfs_inode(file->f_dentry->d_inode); - if ((long)file->f_pos < 0) - return -EINVAL; - DPRINTK(DEBUG_F_READDIR, "(%s): fs_info: %p pos: %ld\n", - parent->name, fs_info, (long)file->f_pos); - switch ((long)file->f_pos) { - case 0: - err = (*filldir) (dirent, "..", 2, file->f_pos, - parent_ino(file->f_dentry), DT_DIR); - if (err == -EINVAL) - break; - if (err < 0) - return err; - file->f_pos++; - ++stored; - /* Fall through */ - case 1: - err = - (*filldir) (dirent, ".", 1, file->f_pos, inode->i_ino, - DT_DIR); - if (err == -EINVAL) - break; - if (err < 0) - return err; - file->f_pos++; - ++stored; - /* Fall through */ - default: - /* Skip entries */ - count = file->f_pos - 2; - read_lock(&parent->u.dir.lock); - for (de = parent->u.dir.first; de && (count > 0); de = de->next) - --count; - devfs_get(de); - read_unlock(&parent->u.dir.lock); - /* Now add all remaining entries */ - while (de) { - err = (*filldir) (dirent, de->name, de->namelen, - file->f_pos, de->inode.ino, - de->mode >> 12); - if (err < 0) - devfs_put(de); - else { - file->f_pos++; - ++stored; - } - if (err == -EINVAL) - break; - if (err < 0) - return err; - read_lock(&parent->u.dir.lock); - next = devfs_get(de->next); - read_unlock(&parent->u.dir.lock); - devfs_put(de); - de = next; - } - break; - } - return stored; -} /* End Function devfs_readdir */ - -/* Open devfs specific special files */ -static int devfs_open(struct inode *inode, struct file *file) -{ - int err; - int minor = MINOR(inode->i_rdev); - struct file_operations *old_fops, *new_fops; - - switch (minor) { - case 0: /* /dev/.devfsd */ - new_fops = fops_get(&devfsd_fops); - break; -#ifdef CONFIG_DEVFS_DEBUG - case 1: /* /dev/.stat */ - new_fops = fops_get(&stat_fops); - break; -#endif - default: - return -ENODEV; - } - - if (new_fops == NULL) - return -ENODEV; - old_fops = file->f_op; - file->f_op = new_fops; - err = new_fops->open ? new_fops->open(inode, file) : 0; - if (err) { - file->f_op = old_fops; - fops_put(new_fops); - } else - fops_put(old_fops); - return err; -} /* End Function devfs_open */ - -static const struct file_operations devfs_fops = { - .open = devfs_open, -}; - -static const struct file_operations devfs_dir_fops = { - .read = generic_read_dir, - .readdir = devfs_readdir, -}; - -/* Dentry operations for device entries follow */ - -/** - * devfs_d_release - Callback for when a dentry is freed. - * @dentry: The dentry. - */ - -static void devfs_d_release(struct dentry *dentry) -{ - DPRINTK(DEBUG_D_RELEASE, "(%p): inode: %p\n", dentry, dentry->d_inode); -} /* End Function devfs_d_release */ - -/** - * devfs_d_iput - Callback for when a dentry loses its inode. - * @dentry: The dentry. - * @inode: The inode. - */ - -static void devfs_d_iput(struct dentry *dentry, struct inode *inode) -{ - struct devfs_entry *de; - - de = get_devfs_entry_from_vfs_inode(inode); - DPRINTK(DEBUG_D_IPUT, - "(%s): dentry: %p inode: %p de: %p de->dentry: %p\n", de->name, - dentry, inode, de, de->inode.dentry); - if (de->inode.dentry && (de->inode.dentry != dentry)) - OOPS("(%s): de: %p dentry: %p de->dentry: %p\n", - de->name, de, dentry, de->inode.dentry); - de->inode.dentry = NULL; - iput(inode); - devfs_put(de); -} /* End Function devfs_d_iput */ - -static int devfs_d_delete(struct dentry *dentry); - -static struct dentry_operations devfs_dops = { - .d_delete = devfs_d_delete, - .d_release = devfs_d_release, - .d_iput = devfs_d_iput, -}; - -static int devfs_d_revalidate_wait(struct dentry *dentry, struct nameidata *); - -static struct dentry_operations devfs_wait_dops = { - .d_delete = devfs_d_delete, - .d_release = devfs_d_release, - .d_iput = devfs_d_iput, - .d_revalidate = devfs_d_revalidate_wait, -}; - -/** - * devfs_d_delete - Callback for when all files for a dentry are closed. - * @dentry: The dentry. - */ - -static int devfs_d_delete(struct dentry *dentry) -{ - struct inode *inode = dentry->d_inode; - - if (dentry->d_op == &devfs_wait_dops) - dentry->d_op = &devfs_dops; - /* Unhash dentry if negative (has no inode) */ - if (inode == NULL) { - DPRINTK(DEBUG_D_DELETE, "(%p): dropping negative dentry\n", - dentry); - return 1; - } - return 0; -} /* End Function devfs_d_delete */ - -struct devfs_lookup_struct { - devfs_handle_t de; - wait_queue_head_t wait_queue; -}; - -/* XXX: this doesn't handle the case where we got a negative dentry - but a devfs entry has been registered in the meanwhile */ -static int devfs_d_revalidate_wait(struct dentry *dentry, struct nameidata *nd) -{ - struct inode *dir = dentry->d_parent->d_inode; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - devfs_handle_t parent = get_devfs_entry_from_vfs_inode(dir); - struct devfs_lookup_struct *lookup_info = dentry->d_fsdata; - DECLARE_WAITQUEUE(wait, current); - int need_lock; - - /* - * FIXME HACK - * - * make sure that - * d_instantiate always runs under lock - * we release i_mutex lock before going to sleep - * - * unfortunately sometimes d_revalidate is called with - * and sometimes without i_mutex lock held. The following checks - * attempt to deduce when we need to add (and drop resp.) lock - * here. This relies on current (2.6.2) calling coventions: - * - * lookup_hash is always run under i_mutex and is passing NULL - * as nd - * - * open(...,O_CREATE,...) calls _lookup_hash under i_mutex - * and sets flags to LOOKUP_OPEN|LOOKUP_CREATE - * - * all other invocations of ->d_revalidate seem to happen - * outside of i_mutex - */ - need_lock = nd && - (!(nd->flags & LOOKUP_CREATE) || (nd->flags & LOOKUP_PARENT)); - - if (need_lock) - mutex_lock(&dir->i_mutex); - - if (is_devfsd_or_child(fs_info)) { - devfs_handle_t de = lookup_info->de; - struct inode *inode; - - DPRINTK(DEBUG_I_LOOKUP, - "(%s): dentry: %p inode: %p de: %p by: \"%s\"\n", - dentry->d_name.name, dentry, dentry->d_inode, de, - current->comm); - if (dentry->d_inode) - goto out; - if (de == NULL) { - read_lock(&parent->u.dir.lock); - de = _devfs_search_dir(parent, dentry->d_name.name, - dentry->d_name.len); - read_unlock(&parent->u.dir.lock); - if (de == NULL) - goto out; - lookup_info->de = de; - } - /* Create an inode, now that the driver information is available */ - inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry); - if (!inode) - goto out; - DPRINTK(DEBUG_I_LOOKUP, - "(%s): new VFS inode(%u): %p de: %p by: \"%s\"\n", - de->name, de->inode.ino, inode, de, current->comm); - d_instantiate(dentry, inode); - goto out; - } - if (lookup_info == NULL) - goto out; /* Early termination */ - read_lock(&parent->u.dir.lock); - if (dentry->d_fsdata) { - set_current_state(TASK_UNINTERRUPTIBLE); - add_wait_queue(&lookup_info->wait_queue, &wait); - read_unlock(&parent->u.dir.lock); - /* at this point it is always (hopefully) locked */ - mutex_unlock(&dir->i_mutex); - schedule(); - mutex_lock(&dir->i_mutex); - /* - * This does not need nor should remove wait from wait_queue. - * Wait queue head is never reused - nothing is ever added to it - * after all waiters have been waked up and head itself disappears - * very soon after it. Moreover it is local variable on stack that - * is likely to have already disappeared so any reference to it - * at this point is buggy. - */ - - } else - read_unlock(&parent->u.dir.lock); - - out: - if (need_lock) - mutex_unlock(&dir->i_mutex); - return 1; -} /* End Function devfs_d_revalidate_wait */ - -/* Inode operations for device entries follow */ - -static struct dentry *devfs_lookup(struct inode *dir, struct dentry *dentry, - struct nameidata *nd) -{ - struct devfs_entry tmp; /* Must stay in scope until devfsd idle again */ - struct devfs_lookup_struct lookup_info; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct devfs_entry *parent, *de; - struct inode *inode; - struct dentry *retval = NULL; - - /* Set up the dentry operations before anything else, to ensure cleaning - up on any error */ - dentry->d_op = &devfs_dops; - /* First try to get the devfs entry for this directory */ - parent = get_devfs_entry_from_vfs_inode(dir); - DPRINTK(DEBUG_I_LOOKUP, "(%s): dentry: %p parent: %p by: \"%s\"\n", - dentry->d_name.name, dentry, parent, current->comm); - if (parent == NULL) - return ERR_PTR(-ENOENT); - read_lock(&parent->u.dir.lock); - de = _devfs_search_dir(parent, dentry->d_name.name, dentry->d_name.len); - read_unlock(&parent->u.dir.lock); - lookup_info.de = de; - init_waitqueue_head(&lookup_info.wait_queue); - dentry->d_fsdata = &lookup_info; - if (de == NULL) { /* Try with devfsd. For any kind of failure, leave a negative dentry - so someone else can deal with it (in the case where the sysadmin - does a mknod()). It's important to do this before hashing the - dentry, so that the devfsd queue is filled before revalidates - can start */ - if (try_modload(parent, fs_info, dentry->d_name.name, dentry->d_name.len, &tmp) < 0) { /* Lookup event was not queued to devfsd */ - d_add(dentry, NULL); - return NULL; - } - } - dentry->d_op = &devfs_wait_dops; - d_add(dentry, NULL); /* Open the floodgates */ - /* Unlock directory semaphore, which will release any waiters. They - will get the hashed dentry, and may be forced to wait for - revalidation */ - mutex_unlock(&dir->i_mutex); - wait_for_devfsd_finished(fs_info); /* If I'm not devfsd, must wait */ - mutex_lock(&dir->i_mutex); /* Grab it again because them's the rules */ - de = lookup_info.de; - /* If someone else has been so kind as to make the inode, we go home - early */ - if (dentry->d_inode) - goto out; - if (de == NULL) { - read_lock(&parent->u.dir.lock); - de = _devfs_search_dir(parent, dentry->d_name.name, - dentry->d_name.len); - read_unlock(&parent->u.dir.lock); - if (de == NULL) - goto out; - /* OK, there's an entry now, but no VFS inode yet */ - } - /* Create an inode, now that the driver information is available */ - inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry); - if (!inode) { - retval = ERR_PTR(-ENOMEM); - goto out; - } - DPRINTK(DEBUG_I_LOOKUP, - "(%s): new VFS inode(%u): %p de: %p by: \"%s\"\n", de->name, - de->inode.ino, inode, de, current->comm); - d_instantiate(dentry, inode); - out: - write_lock(&parent->u.dir.lock); - dentry->d_op = &devfs_dops; - dentry->d_fsdata = NULL; - wake_up(&lookup_info.wait_queue); - write_unlock(&parent->u.dir.lock); - devfs_put(de); - return retval; -} /* End Function devfs_lookup */ - -static int devfs_unlink(struct inode *dir, struct dentry *dentry) -{ - int unhooked; - struct devfs_entry *de; - struct inode *inode = dentry->d_inode; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - - de = get_devfs_entry_from_vfs_inode(inode); - DPRINTK(DEBUG_I_UNLINK, "(%s): de: %p\n", dentry->d_name.name, de); - if (de == NULL) - return -ENOENT; - if (!de->vfs) - return -EPERM; - write_lock(&de->parent->u.dir.lock); - unhooked = _devfs_unhook(de); - write_unlock(&de->parent->u.dir.lock); - if (!unhooked) - return -ENOENT; - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_DELETE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - free_dentry(de); - devfs_put(de); - return 0; -} /* End Function devfs_unlink */ - -static int devfs_symlink(struct inode *dir, struct dentry *dentry, - const char *symname) -{ - int err; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct devfs_entry *parent, *de; - struct inode *inode; - - /* First try to get the devfs entry for this directory */ - parent = get_devfs_entry_from_vfs_inode(dir); - if (parent == NULL) - return -ENOENT; - err = devfs_do_symlink(parent, dentry->d_name.name, symname, &de); - DPRINTK(DEBUG_DISABLED, "(%s): errcode from : %d\n", - dentry->d_name.name, err); - if (err < 0) - return err; - de->vfs = TRUE; - de->inode.uid = current->euid; - de->inode.gid = current->egid; - de->inode.atime = CURRENT_TIME; - de->inode.mtime = CURRENT_TIME; - de->inode.ctime = CURRENT_TIME; - if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL) - return -ENOMEM; - DPRINTK(DEBUG_DISABLED, "(%s): new VFS inode(%u): %p dentry: %p\n", - dentry->d_name.name, de->inode.ino, inode, dentry); - d_instantiate(dentry, inode); - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - return 0; -} /* End Function devfs_symlink */ - -static int devfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) -{ - int err; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct devfs_entry *parent, *de; - struct inode *inode; - - mode = (mode & ~S_IFMT) | S_IFDIR; /* VFS doesn't pass S_IFMT part */ - parent = get_devfs_entry_from_vfs_inode(dir); - if (parent == NULL) - return -ENOENT; - de = _devfs_alloc_entry(dentry->d_name.name, dentry->d_name.len, mode); - if (!de) - return -ENOMEM; - de->vfs = TRUE; - if ((err = _devfs_append_entry(parent, de, NULL)) != 0) - return err; - de->inode.uid = current->euid; - de->inode.gid = current->egid; - de->inode.atime = CURRENT_TIME; - de->inode.mtime = CURRENT_TIME; - de->inode.ctime = CURRENT_TIME; - if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL) - return -ENOMEM; - DPRINTK(DEBUG_DISABLED, "(%s): new VFS inode(%u): %p dentry: %p\n", - dentry->d_name.name, de->inode.ino, inode, dentry); - d_instantiate(dentry, inode); - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - return 0; -} /* End Function devfs_mkdir */ - -static int devfs_rmdir(struct inode *dir, struct dentry *dentry) -{ - int err = 0; - struct devfs_entry *de; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct inode *inode = dentry->d_inode; - - if (dir->i_sb->s_fs_info != inode->i_sb->s_fs_info) - return -EINVAL; - de = get_devfs_entry_from_vfs_inode(inode); - if (de == NULL) - return -ENOENT; - if (!S_ISDIR(de->mode)) - return -ENOTDIR; - if (!de->vfs) - return -EPERM; - /* First ensure the directory is empty and will stay that way */ - write_lock(&de->u.dir.lock); - if (de->u.dir.first) - err = -ENOTEMPTY; - else - de->u.dir.no_more_additions = TRUE; - write_unlock(&de->u.dir.lock); - if (err) - return err; - /* Now unhook the directory from its parent */ - write_lock(&de->parent->u.dir.lock); - if (!_devfs_unhook(de)) - err = -ENOENT; - write_unlock(&de->parent->u.dir.lock); - if (err) - return err; - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_DELETE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - free_dentry(de); - devfs_put(de); - return 0; -} /* End Function devfs_rmdir */ - -static int devfs_mknod(struct inode *dir, struct dentry *dentry, int mode, - dev_t rdev) -{ - int err; - struct fs_info *fs_info = dir->i_sb->s_fs_info; - struct devfs_entry *parent, *de; - struct inode *inode; - - DPRINTK(DEBUG_I_MKNOD, "(%s): mode: 0%o dev: %u:%u\n", - dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev)); - parent = get_devfs_entry_from_vfs_inode(dir); - if (parent == NULL) - return -ENOENT; - de = _devfs_alloc_entry(dentry->d_name.name, dentry->d_name.len, mode); - if (!de) - return -ENOMEM; - de->vfs = TRUE; - if (S_ISCHR(mode) || S_ISBLK(mode)) - de->u.dev = rdev; - if ((err = _devfs_append_entry(parent, de, NULL)) != 0) - return err; - de->inode.uid = current->euid; - de->inode.gid = current->egid; - de->inode.atime = CURRENT_TIME; - de->inode.mtime = CURRENT_TIME; - de->inode.ctime = CURRENT_TIME; - if ((inode = _devfs_get_vfs_inode(dir->i_sb, de, dentry)) == NULL) - return -ENOMEM; - DPRINTK(DEBUG_I_MKNOD, ": new VFS inode(%u): %p dentry: %p\n", - de->inode.ino, inode, dentry); - d_instantiate(dentry, inode); - if (!is_devfsd_or_child(fs_info)) - devfsd_notify_de(de, DEVFSD_NOTIFY_CREATE, inode->i_mode, - inode->i_uid, inode->i_gid, fs_info); - return 0; -} /* End Function devfs_mknod */ - -static void *devfs_follow_link(struct dentry *dentry, struct nameidata *nd) -{ - struct devfs_entry *p = get_devfs_entry_from_vfs_inode(dentry->d_inode); - nd_set_link(nd, p ? p->u.symlink.linkname : ERR_PTR(-ENODEV)); - return NULL; -} /* End Function devfs_follow_link */ - -static struct inode_operations devfs_iops = { - .setattr = devfs_notify_change, -}; - -static struct inode_operations devfs_dir_iops = { - .lookup = devfs_lookup, - .unlink = devfs_unlink, - .symlink = devfs_symlink, - .mkdir = devfs_mkdir, - .rmdir = devfs_rmdir, - .mknod = devfs_mknod, - .setattr = devfs_notify_change, -}; - -static struct inode_operations devfs_symlink_iops = { - .readlink = generic_readlink, - .follow_link = devfs_follow_link, - .setattr = devfs_notify_change, -}; - -static int devfs_fill_super(struct super_block *sb, void *data, int silent) -{ - struct inode *root_inode = NULL; - - if (_devfs_get_root_entry() == NULL) - goto out_no_root; - atomic_set(&fs_info.devfsd_overrun_count, 0); - init_waitqueue_head(&fs_info.devfsd_wait_queue); - init_waitqueue_head(&fs_info.revalidate_wait_queue); - fs_info.sb = sb; - sb->s_fs_info = &fs_info; - sb->s_blocksize = 1024; - sb->s_blocksize_bits = 10; - sb->s_magic = DEVFS_SUPER_MAGIC; - sb->s_op = &devfs_sops; - sb->s_time_gran = 1; - if ((root_inode = _devfs_get_vfs_inode(sb, root_entry, NULL)) == NULL) - goto out_no_root; - sb->s_root = d_alloc_root(root_inode); - if (!sb->s_root) - goto out_no_root; - DPRINTK(DEBUG_S_READ, "(): made devfs ptr: %p\n", sb->s_fs_info); - return 0; - - out_no_root: - PRINTK("(): get root inode failed\n"); - if (root_inode) - iput(root_inode); - return -EINVAL; -} /* End Function devfs_fill_super */ - -static int devfs_get_sb(struct file_system_type *fs_type, - int flags, const char *dev_name, - void *data, struct vfsmount *mnt) -{ - return get_sb_single(fs_type, flags, data, devfs_fill_super, mnt); -} - -static struct file_system_type devfs_fs_type = { - .name = DEVFS_NAME, - .get_sb = devfs_get_sb, - .kill_sb = kill_anon_super, -}; - -/* File operations for devfsd follow */ - -static ssize_t devfsd_read(struct file *file, char __user *buf, size_t len, - loff_t * ppos) -{ - int done = FALSE; - int ival; - loff_t pos, devname_offset, tlen, rpos; - devfs_handle_t de; - struct devfsd_buf_entry *entry; - struct fs_info *fs_info = file->f_dentry->d_inode->i_sb->s_fs_info; - struct devfsd_notify_struct *info = fs_info->devfsd_info; - DECLARE_WAITQUEUE(wait, current); - - /* Verify the task has grabbed the queue */ - if (fs_info->devfsd_task != current) - return -EPERM; - info->major = 0; - info->minor = 0; - /* Block for a new entry */ - set_current_state(TASK_INTERRUPTIBLE); - add_wait_queue(&fs_info->devfsd_wait_queue, &wait); - while (devfsd_queue_empty(fs_info)) { - fs_info->devfsd_sleeping = TRUE; - wake_up(&fs_info->revalidate_wait_queue); - schedule(); - fs_info->devfsd_sleeping = FALSE; - if (signal_pending(current)) { - remove_wait_queue(&fs_info->devfsd_wait_queue, &wait); - __set_current_state(TASK_RUNNING); - return -EINTR; - } - set_current_state(TASK_INTERRUPTIBLE); - } - remove_wait_queue(&fs_info->devfsd_wait_queue, &wait); - __set_current_state(TASK_RUNNING); - /* Now play with the data */ - ival = atomic_read(&fs_info->devfsd_overrun_count); - info->overrun_count = ival; - entry = fs_info->devfsd_first_event; - info->type = entry->type; - info->mode = entry->mode; - info->uid = entry->uid; - info->gid = entry->gid; - de = entry->de; - if (S_ISCHR(de->mode) || S_ISBLK(de->mode)) { - info->major = MAJOR(de->u.dev); - info->minor = MINOR(de->u.dev); - } - pos = devfs_generate_path(de, info->devname, DEVFS_PATHLEN); - if (pos < 0) - return pos; - info->namelen = DEVFS_PATHLEN - pos - 1; - if (info->mode == 0) - info->mode = de->mode; - devname_offset = info->devname - (char *)info; - rpos = *ppos; - if (rpos < devname_offset) { - /* Copy parts of the header */ - tlen = devname_offset - rpos; - if (tlen > len) - tlen = len; - if (copy_to_user(buf, (char *)info + rpos, tlen)) { - return -EFAULT; - } - rpos += tlen; - buf += tlen; - len -= tlen; - } - if ((rpos >= devname_offset) && (len > 0)) { - /* Copy the name */ - tlen = info->namelen + 1; - if (tlen > len) - tlen = len; - else - done = TRUE; - if (copy_to_user - (buf, info->devname + pos + rpos - devname_offset, tlen)) { - return -EFAULT; - } - rpos += tlen; - } - tlen = rpos - *ppos; - if (done) { - devfs_handle_t parent; - - spin_lock(&fs_info->devfsd_buffer_lock); - fs_info->devfsd_first_event = entry->next; - if (entry->next == NULL) - fs_info->devfsd_last_event = NULL; - spin_unlock(&fs_info->devfsd_buffer_lock); - for (; de != NULL; de = parent) { - parent = de->parent; - devfs_put(de); - } - kmem_cache_free(devfsd_buf_cache, entry); - if (ival > 0) - atomic_sub(ival, &fs_info->devfsd_overrun_count); - *ppos = 0; - } else - *ppos = rpos; - return tlen; -} /* End Function devfsd_read */ - -static int devfsd_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) -{ - int ival; - struct fs_info *fs_info = inode->i_sb->s_fs_info; - - switch (cmd) { - case DEVFSDIOC_GET_PROTO_REV: - ival = DEVFSD_PROTOCOL_REVISION_KERNEL; - if (copy_to_user((void __user *)arg, &ival, sizeof ival)) - return -EFAULT; - break; - case DEVFSDIOC_SET_EVENT_MASK: - /* Ensure only one reader has access to the queue. This scheme will - work even if the global kernel lock were to be removed, because it - doesn't matter who gets in first, as long as only one gets it */ - if (fs_info->devfsd_task == NULL) { - static DEFINE_SPINLOCK(lock); - - if (!spin_trylock(&lock)) - return -EBUSY; - if (fs_info->devfsd_task != NULL) { /* We lost the race... */ - spin_unlock(&lock); - return -EBUSY; - } - fs_info->devfsd_task = current; - spin_unlock(&lock); - fs_info->devfsd_pgrp = - (process_group(current) == - current->pid) ? process_group(current) : 0; - fs_info->devfsd_file = file; - fs_info->devfsd_info = - kmalloc(sizeof *fs_info->devfsd_info, GFP_KERNEL); - if (!fs_info->devfsd_info) { - devfsd_close(inode, file); - return -ENOMEM; - } - } else if (fs_info->devfsd_task != current) - return -EBUSY; - fs_info->devfsd_event_mask = arg; /* Let the masses come forth */ - break; - case DEVFSDIOC_RELEASE_EVENT_QUEUE: - if (fs_info->devfsd_file != file) - return -EPERM; - return devfsd_close(inode, file); - /*break; */ -#ifdef CONFIG_DEVFS_DEBUG - case DEVFSDIOC_SET_DEBUG_MASK: - if (copy_from_user(&ival, (void __user *)arg, sizeof ival)) - return -EFAULT; - devfs_debug = ival; - break; -#endif - default: - return -ENOIOCTLCMD; - } - return 0; -} /* End Function devfsd_ioctl */ - -static int devfsd_close(struct inode *inode, struct file *file) -{ - struct devfsd_buf_entry *entry, *next; - struct fs_info *fs_info = inode->i_sb->s_fs_info; - - if (fs_info->devfsd_file != file) - return 0; - fs_info->devfsd_event_mask = 0; - fs_info->devfsd_file = NULL; - spin_lock(&fs_info->devfsd_buffer_lock); - entry = fs_info->devfsd_first_event; - fs_info->devfsd_first_event = NULL; - fs_info->devfsd_last_event = NULL; - kfree(fs_info->devfsd_info); - fs_info->devfsd_info = NULL; - spin_unlock(&fs_info->devfsd_buffer_lock); - fs_info->devfsd_pgrp = 0; - fs_info->devfsd_task = NULL; - wake_up(&fs_info->revalidate_wait_queue); - for (; entry; entry = next) { - next = entry->next; - kmem_cache_free(devfsd_buf_cache, entry); - } - return 0; -} /* End Function devfsd_close */ - -#ifdef CONFIG_DEVFS_DEBUG -static ssize_t stat_read(struct file *file, char __user *buf, size_t len, - loff_t * ppos) -{ - ssize_t num; - char txt[80]; - - num = sprintf(txt, "Number of entries: %u number of bytes: %u\n", - stat_num_entries, stat_num_bytes) + 1; - if (*ppos >= num) - return 0; - if (*ppos + len > num) - len = num - *ppos; - if (copy_to_user(buf, txt + *ppos, len)) - return -EFAULT; - *ppos += len; - return len; -} /* End Function stat_read */ -#endif - -static int __init init_devfs_fs(void) -{ - int err; - int major; - struct devfs_entry *devfsd; -#ifdef CONFIG_DEVFS_DEBUG - struct devfs_entry *stat; -#endif - - if (_devfs_get_root_entry() == NULL) - return -ENOMEM; - - printk(KERN_INFO "%s: %s Richard Gooch (rgooch@atnf.csiro.au)\n", - DEVFS_NAME, DEVFS_VERSION); - devfsd_buf_cache = kmem_cache_create("devfsd_event", - sizeof(struct devfsd_buf_entry), - 0, 0, NULL, NULL); - if (!devfsd_buf_cache) - OOPS("(): unable to allocate event slab\n"); -#ifdef CONFIG_DEVFS_DEBUG - devfs_debug = devfs_debug_init; - printk(KERN_INFO "%s: devfs_debug: 0x%0x\n", DEVFS_NAME, devfs_debug); -#endif - printk(KERN_INFO "%s: boot_options: 0x%0x\n", DEVFS_NAME, boot_options); - - /* register special device for devfsd communication */ - major = register_chrdev(0, "devfs", &devfs_fops); - if (major < 0) - return major; - - /* And create the entry for ".devfsd" */ - devfsd = _devfs_alloc_entry(".devfsd", 0, S_IFCHR | S_IRUSR | S_IWUSR); - if (devfsd == NULL) - return -ENOMEM; - devfsd->u.dev = MKDEV(major, 0); - _devfs_append_entry(root_entry, devfsd, NULL); - -#ifdef CONFIG_DEVFS_DEBUG - stat = _devfs_alloc_entry(".stat", 0, S_IFCHR | S_IRUGO); - if (stat == NULL) - return -ENOMEM; - stat->u.dev = MKDEV(major, 1); - _devfs_append_entry(root_entry, stat, NULL); -#endif - - err = register_filesystem(&devfs_fs_type); - return err; -} /* End Function init_devfs_fs */ - -void __init mount_devfs_fs(void) -{ - int err; - - if (!(boot_options & OPTION_MOUNT)) - return; - err = do_mount("none", "/dev", "devfs", 0, NULL); - if (err == 0) - printk(KERN_INFO "Mounted devfs on /dev\n"); - else - PRINTK("(): unable to mount devfs, err: %d\n", err); -} /* End Function mount_devfs_fs */ - -module_init(init_devfs_fs) diff --git a/fs/devfs/util.c b/fs/devfs/util.c deleted file mode 100644 index db06d388c9a..00000000000 --- a/fs/devfs/util.c +++ /dev/null @@ -1,97 +0,0 @@ -/* devfs (Device FileSystem) utilities. - - Copyright (C) 1999-2002 Richard Gooch - - This library is free software; you can redistribute it and/or - modify it under the terms of the GNU Library General Public - License as published by the Free Software Foundation; either - version 2 of the License, or (at your option) any later version. - - This library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Library General Public License for more details. - - You should have received a copy of the GNU Library General Public - License along with this library; if not, write to the Free - Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - - Richard Gooch may be reached by email at rgooch@atnf.csiro.au - The postal address is: - Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia. - - ChangeLog - - 19991031 Richard Gooch - Created. - 19991103 Richard Gooch - Created <_devfs_convert_name> and supported SCSI and IDE CD-ROMs - 20000203 Richard Gooch - Changed operations pointer type to void *. - 20000621 Richard Gooch - Changed interface to . - 20000622 Richard Gooch - Took account of interface change to . - Took account of interface change to . - 20010519 Richard Gooch - Documentation cleanup. - 20010709 Richard Gooch - Created and . - 20010710 Richard Gooch - Created . - 20010730 Richard Gooch - Documentation typo fix. - 20010806 Richard Gooch - Made and private. - 20010813 Richard Gooch - Fixed bug in : limited to 128 numbers - 20010818 Richard Gooch - Updated major masks up to Linus' "no new majors" proclamation. - Block: were 126 now 122 free, char: were 26 now 19 free. - 20020324 Richard Gooch - Fixed bug in : was clearing beyond - bitfield. - 20020326 Richard Gooch - Fixed bitfield data type for . - Made major bitfield type and initialiser 64 bit safe. - 20020413 Richard Gooch - Fixed shift warning on 64 bit machines. - 20020428 Richard Gooch - Copied and used macro for error messages from fs/devfs/base.c - 20021013 Richard Gooch - Documentation fix. - 20030101 Adam J. Richter - Eliminate DEVFS_SPECIAL_{CHR,BLK}. Use mode_t instead. - 20030106 Christoph Hellwig - Rewrite devfs_{,de}alloc_devnum to look like C code. -*/ -#include -#include -#include -#include -#include -#include -#include - -int devfs_register_tape(const char *name) -{ - char tname[32], dest[64]; - static unsigned int tape_counter; - unsigned int n = tape_counter++; - - sprintf(dest, "../%s", name); - sprintf(tname, "tapes/tape%u", n); - devfs_mk_symlink(tname, dest); - - return n; -} - -EXPORT_SYMBOL(devfs_register_tape); - -void devfs_unregister_tape(int num) -{ - if (num >= 0) - devfs_remove("tapes/tape%u", num); -} - -EXPORT_SYMBOL(devfs_unregister_tape); diff --git a/include/linux/compat_ioctl.h b/include/linux/compat_ioctl.h index 917d62e4148..269d000bb2a 100644 --- a/include/linux/compat_ioctl.h +++ b/include/linux/compat_ioctl.h @@ -567,11 +567,6 @@ COMPATIBLE_IOCTL(AUTOFS_IOC_PROTOSUBVER) COMPATIBLE_IOCTL(AUTOFS_IOC_ASKREGHOST) COMPATIBLE_IOCTL(AUTOFS_IOC_TOGGLEREGHOST) COMPATIBLE_IOCTL(AUTOFS_IOC_ASKUMOUNT) -/* DEVFS */ -COMPATIBLE_IOCTL(DEVFSDIOC_GET_PROTO_REV) -COMPATIBLE_IOCTL(DEVFSDIOC_SET_EVENT_MASK) -COMPATIBLE_IOCTL(DEVFSDIOC_RELEASE_EVENT_QUEUE) -COMPATIBLE_IOCTL(DEVFSDIOC_SET_DEBUG_MASK) /* Raw devices */ COMPATIBLE_IOCTL(RAW_SETBIND) COMPATIBLE_IOCTL(RAW_GETBIND) diff --git a/include/linux/devfs_fs.h b/include/linux/devfs_fs.h deleted file mode 100644 index de236f43187..00000000000 --- a/include/linux/devfs_fs.h +++ /dev/null @@ -1,41 +0,0 @@ -#ifndef _LINUX_DEVFS_FS_H -#define _LINUX_DEVFS_FS_H - -#include - -#define DEVFSD_PROTOCOL_REVISION_KERNEL 5 - -#define DEVFSD_IOCTL_BASE 'd' - -/* These are the various ioctls */ -#define DEVFSDIOC_GET_PROTO_REV _IOR(DEVFSD_IOCTL_BASE, 0, int) -#define DEVFSDIOC_SET_EVENT_MASK _IOW(DEVFSD_IOCTL_BASE, 2, int) -#define DEVFSDIOC_RELEASE_EVENT_QUEUE _IOW(DEVFSD_IOCTL_BASE, 3, int) -#define DEVFSDIOC_SET_DEBUG_MASK _IOW(DEVFSD_IOCTL_BASE, 4, int) - -#define DEVFSD_NOTIFY_REGISTERED 0 -#define DEVFSD_NOTIFY_UNREGISTERED 1 -#define DEVFSD_NOTIFY_ASYNC_OPEN 2 -#define DEVFSD_NOTIFY_CLOSE 3 -#define DEVFSD_NOTIFY_LOOKUP 4 -#define DEVFSD_NOTIFY_CHANGE 5 -#define DEVFSD_NOTIFY_CREATE 6 -#define DEVFSD_NOTIFY_DELETE 7 - -#define DEVFS_PATHLEN 1024 /* Never change this otherwise the - binary interface will change */ - -struct devfsd_notify_struct { /* Use native C types to ensure same types in kernel and user space */ - unsigned int type; /* DEVFSD_NOTIFY_* value */ - unsigned int mode; /* Mode of the inode or device entry */ - unsigned int major; /* Major number of device entry */ - unsigned int minor; /* Minor number of device entry */ - unsigned int uid; /* Uid of process, inode or device entry */ - unsigned int gid; /* Gid of process, inode or device entry */ - unsigned int overrun_count; /* Number of lost events */ - unsigned int namelen; /* Number of characters not including '\0' */ - /* The device name MUST come last */ - char devname[DEVFS_PATHLEN]; /* This will be '\0' terminated */ -}; - -#endif /* _LINUX_DEVFS_FS_H */ diff --git a/include/linux/devfs_fs_kernel.h b/include/linux/devfs_fs_kernel.h index 0d74a6f22ab..ef34d7ffe49 100644 --- a/include/linux/devfs_fs_kernel.h +++ b/include/linux/devfs_fs_kernel.h @@ -4,25 +4,8 @@ #include #include #include - #include -#define DEVFS_SUPER_MAGIC 0x1373 - -#ifdef CONFIG_DEVFS_FS -extern int devfs_mk_bdev(dev_t dev, umode_t mode, const char *fmt, ...) - __attribute__ ((format(printf, 3, 4))); -extern int devfs_mk_cdev(dev_t dev, umode_t mode, const char *fmt, ...) - __attribute__ ((format(printf, 3, 4))); -extern int devfs_mk_symlink(const char *name, const char *link); -extern int devfs_mk_dir(const char *fmt, ...) - __attribute__ ((format(printf, 1, 2))); -extern void devfs_remove(const char *fmt, ...) - __attribute__ ((format(printf, 1, 2))); -extern int devfs_register_tape(const char *name); -extern void devfs_unregister_tape(int num); -extern void mount_devfs_fs(void); -#else /* CONFIG_DEVFS_FS */ static inline int devfs_mk_bdev(dev_t dev, umode_t mode, const char *fmt, ...) { return 0; @@ -53,5 +36,4 @@ static inline void mount_devfs_fs(void) { return; } -#endif /* CONFIG_DEVFS_FS */ #endif /* _LINUX_DEVFS_FS_KERNEL_H */ -- cgit v1.2.3 From 5c3927dc3468f47b803c9e1bb82cbed2bbd411ab Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 20 Jun 2005 21:15:16 -0700 Subject: [PATCH] devfs: Remove devfs documentation from the kernel tree Removes the Documentaiton/filesystems/devfs/ directory Signed-off-by: Greg Kroah-Hartman --- Documentation/filesystems/devfs/ChangeLog | 1977 -------------------------- Documentation/filesystems/devfs/README | 1959 ------------------------- Documentation/filesystems/devfs/ToDo | 40 - Documentation/filesystems/devfs/boot-options | 65 - 4 files changed, 4041 deletions(-) delete mode 100644 Documentation/filesystems/devfs/ChangeLog delete mode 100644 Documentation/filesystems/devfs/README delete mode 100644 Documentation/filesystems/devfs/ToDo delete mode 100644 Documentation/filesystems/devfs/boot-options diff --git a/Documentation/filesystems/devfs/ChangeLog b/Documentation/filesystems/devfs/ChangeLog deleted file mode 100644 index e5aba5246d7..00000000000 --- a/Documentation/filesystems/devfs/ChangeLog +++ /dev/null @@ -1,1977 +0,0 @@ -/* -*- auto-fill -*- */ -=============================================================================== -Changes for patch v1 - -- creation of devfs - -- modified miscellaneous character devices to support devfs -=============================================================================== -Changes for patch v2 - -- bug fix with manual inode creation -=============================================================================== -Changes for patch v3 - -- bugfixes - -- documentation improvements - -- created a couple of scripts (one to save&restore a devfs and the - other to set up compatibility symlinks) - -- devfs support for SCSI discs. New name format is: sd_hHcCiIlL -=============================================================================== -Changes for patch v4 - -- bugfix for the directory reading code - -- bugfix for compilation with kerneld - -- devfs support for generic hard discs - -- rationalisation of the various watchdog drivers -=============================================================================== -Changes for patch v5 - -- support for mounting directly from entries in the devfs (it doesn't - need to be mounted to do this), including the root filesystem. - Mounting of swap partitions also works. Hence, now if you set - CONFIG_DEVFS_ONLY to 'Y' then you won't be able to access your discs - via ordinary device nodes. Naturally, the default is 'N' so that you - can still use your old device nodes. If you want to mount from devfs - entries, make sure you use: append = "root=/dev/sd_..." in your - lilo.conf. It seems LILO looks for the device number (major&minor) - and writes that into the kernel image :-( - -- support for character memory devices (/dev/null, /dev/zero, /dev/full - and so on). Thanks to C. Scott Ananian -=============================================================================== -Changes for patch v6 - -- support for subdirectories - -- support for symbolic links (created by devfs_mk_symlink(), no - support yet for creation via symlink(2)) - -- SCSI disc naming now cast in stone, with the format: - /dev/sd/c0b1t2u3 controller=0, bus=1, ID=2, LUN=3, whole disc - /dev/sd/c0b1t2u3p4 controller=0, bus=1, ID=2, LUN=3, 4th partition - -- loop devices now appear in devfs - -- tty devices, console, serial ports, etc. now appear in devfs - Thanks to C. Scott Ananian - -- bugs with mounting devfs-only devices now fixed -=============================================================================== -Changes for patch v7 - -- SCSI CD-ROMS, tapes and generic devices now appear in devfs -=============================================================================== -Changes for patch v8 - -- bugfix with no-rewind SCSI tapes - -- RAMDISCs now appear in devfs - -- better cleaning up of devfs entries created by various modules - -- interface change to -=============================================================================== -Changes for patch v9 - -- the v8 patch was corrupted somehow, which would affect the patch for - linux/fs/filesystems.c - I've also fixed the v8 patch file on the WWW - -- MetaDevices (/dev/md*) should now appear in devfs -=============================================================================== -Changes for patch v10 - -- bugfix in meta device support for devfs - -- created this ChangeLog file - -- added devfs support to the floppy driver - -- added support for creating sockets in a devfs -=============================================================================== -Changes for patch v11 - -- added DEVFS_FL_HIDE_UNREG flag - -- incorporated better patch for ttyname() in libc 5.4.43 from H.J. Lu. - -- interface change to - -- support for creating symlinks with symlink(2) - -- parallel port printer (/dev/lp*) now appears in devfs -=============================================================================== -Changes for patch v12 - -- added inode check to function - -- improved devfs support when mounting from devfs - -- added call to <> operation when removing swap areas on - devfs devices - -- increased NR_SUPER to 128 to support large numbers of devfs mounts - (for chroot(2) gaols) - -- fixed bug in SCSI disc support: was generating incorrect minors if - SCSI ID's did not start at 0 and increase by 1 - -- support symlink traversal when mounting root -=============================================================================== -Changes for patch v13 - -- added devfs support to soundcard driver - Thanks to Eric Dumas and - C. Scott Ananian - -- added devfs support to the joystick driver - -- loop driver now has it's own subdirectory "/dev/loop/" - -- created and functions - -- fix problem with SCSI disc compatibility names (sd{a,b,c,d,e,f}) - which assumes ID's start at 0 and increase by 1. Also only create - devfs entries for SCSI disc partitions which actually exist - Show new names in partition check - Thanks to Jakub Jelinek -=============================================================================== -Changes for patch v14 - -- bug fix in floppy driver: would not compile without - CONFIG_DEVFS_FS='Y' - Thanks to Jurgen Botz - -- bug fix in loop driver - Thanks to C. Scott Ananian - -- do not create devfs entries for printers not configured - Thanks to C. Scott Ananian - -- do not create devfs entries for serial ports not present - Thanks to C. Scott Ananian - -- ensure is exported from tty_io.c - Thanks to C. Scott Ananian - -- allow unregistering of devfs symlink entries - -- fixed bug in SCSI disc naming introduced in last patch version -=============================================================================== -Changes for patch v15 - -- ported to kernel 2.1.81 -=============================================================================== -Changes for patch v16 - -- created function - -- moved DEVFS_SUPER_MAGIC into header file - -- added DEVFS_FL_HIDE flag - -- created - -- created - -- fixed bugs in searching by major&minor - -- changed interface to , and - - -- fixed inode times when symlink created with symlink(2) - -- change tty driver to do auto-creation of devfs entries - Thanks to C. Scott Ananian - -- fixed bug in genhd.c: whole disc (non-SCSI) was not registered to - devfs - -- updated libc 5.4.43 patch for ttyname() -=============================================================================== -Changes for patch v17 - -- added CONFIG_DEVFS_TTY_COMPAT - Thanks to C. Scott Ananian - -- bugfix in devfs support for drivers/char/lp.c - Thanks to C. Scott Ananian - -- clean up serial driver so that PCMCIA devices unregister correctly - Thanks to C. Scott Ananian - -- fixed bug in genhd.c: whole disc (non-SCSI) was not registered to - devfs [was missing in patch v16] - -- updated libc 5.4.43 patch for ttyname() [was missing in patch v16] - -- all SCSI devices now registered in /dev/sg - -- support removal of devfs entries via unlink(2) -=============================================================================== -Changes for patch v18 - -- added floppy/?u720 floppy entry - -- fixed kerneld support for entries in devfs subdirectories - -- incorporated latest patch for ttyname() in libc 5.4.43 from H.J. Lu. -=============================================================================== -Changes for patch v19 - -- bug fix when looking up unregistered entries: kerneld was not called - -- fixes for kernel 2.1.86 (now requires 2.1.86) -=============================================================================== -Changes for patch v20 - -- only create available floppy entries - Thanks to Andrzej Krzysztofowicz - -- new IDE naming scheme following SCSI format (i.e. /dev/id/c0b0t0u0p1 - instead of /dev/hda1) - Thanks to Andrzej Krzysztofowicz - -- new XT disc naming scheme following SCSI format (i.e. /dev/xd/c0t0p1 - instead of /dev/xda1) - Thanks to Andrzej Krzysztofowicz - -- new non-standard CD-ROM names (i.e. /dev/sbp/c#t#) - Thanks to Andrzej Krzysztofowicz - -- allow symlink traversal when mounting the root filesystem - -- Create entries for MD devices at MD init - Thanks to Christophe Leroy -=============================================================================== -Changes for patch v21 - -- ported to kernel 2.1.91 -=============================================================================== -Changes for patch v22 - -- SCSI host number patch ("scsihosts=" kernel option) - Thanks to Andrzej Krzysztofowicz -=============================================================================== -Changes for patch v23 - -- Fixed persistence bug with device numbers for manually created - device files - -- Fixed problem with recreating symlinks with different content - -- Added CONFIG_DEVFS_MOUNT (mount devfs on /dev at boot time) -=============================================================================== -Changes for patch v24 - -- Switched from CONFIG_KERNELD to CONFIG_KMOD: module autoloading - should now work again - -- Hide entries which are manually unlinked - -- Always invalidate devfs dentry cache when registering entries - -- Support removal of devfs directories via rmdir(2) - -- Ensure directories created by are visible - -- Default no access for "other" for floppy device -=============================================================================== -Changes for patch v25 - -- Updates to CREDITS file and minor IDE numbering change - Thanks to Andrzej Krzysztofowicz - -- Invalidate devfs dentry cache when making directories - -- Invalidate devfs dentry cache when removing entries - -- More informative message if root FS mount fails when devfs - configured - -- Fixed persistence bug with fifos -=============================================================================== -Changes for patch v26 - -- ported to kernel 2.1.97 - -- Changed serial directory from "/dev/serial" to "/dev/tts" and - "/dev/consoles" to "/dev/vc" to be more friendly to new procps -=============================================================================== -Changes for patch v27 - -- Added support for IDE4 and IDE5 - Thanks to Andrzej Krzysztofowicz - -- Documented "scsihosts=" boot parameter - -- Print process command when debugging kerneld/kmod - -- Added debugging for register/unregister/change operations - -- Added "devfs=" boot options - -- Hide unregistered entries by default -=============================================================================== -Changes for patch v28 - -- No longer lock/unlock superblock in (cope with - recent VFS interface change) - -- Do not automatically change ownership/protection of /dev/tty - -- Drop negative dentries when they are released - -- Manage dcache more efficiently -=============================================================================== -Changes for patch v29 - -- Added DEVFS_FL_AUTO_DEVNUM flag -=============================================================================== -Changes for patch v30 - -- No longer set unnecessary methods - -- Ported to kernel 2.1.99-pre3 -=============================================================================== -Changes for patch v31 - -- Added PID display to debugging message - -- Added "diread" and "diwrite" options - -- Ported to kernel 2.1.102 - -- Fixed persistence problem with permissions -=============================================================================== -Changes for patch v32 - -- Fixed devfs support in drivers/block/md.c -=============================================================================== -Changes for patch v33 - -- Support legacy device nodes - -- Fixed bug where recreated inodes were hidden - -- New IDE naming scheme: everything is under /dev/ide -=============================================================================== -Changes for patch v34 - -- Improved debugging in - -- Prevent duplicate calls to in SCSI layer - -- No longer free old dentries in - -- Free all dentries for a given entry when deleting inodes -=============================================================================== -Changes for patch v35 - -- Ported to kernel 2.1.105 (sound driver changes) -=============================================================================== -Changes for patch v36 - -- Fixed sound driver port -=============================================================================== -Changes for patch v37 - -- Minor documentation tweaks -=============================================================================== -Changes for patch v38 - -- More documentation tweaks - -- Fix for sound driver port - -- Removed ttyname-patch (grab libc 5.4.44 instead) - -- Ported to kernel 2.1.107-pre2 (loop driver fix) -=============================================================================== -Changes for patch v39 - -- Ported to kernel 2.1.107 (hd.c hunk broke due to spelling "fixes"). Sigh - -- Removed many #ifdef's, replaced with trickery in include/devfs_fs.h -=============================================================================== -Changes for patch v40 - -- Fix for sound driver port - -- Limit auto-device numbering to majors 128 to 239 -=============================================================================== -Changes for patch v41 - -- Fixed inode times persistence problem -=============================================================================== -Changes for patch v42 - -- Ported to kernel 2.1.108 (drivers/scsi/hosts.c hunk broke) -=============================================================================== -Changes for patch v43 - -- Fixed spelling in debug - -- Fixed bug in parsing "dilookup" - -- More #ifdef's removed - -- Supported Sparc keyboard (/dev/kbd) - -- Supported DSP56001 digital signal processor (/dev/dsp56k) - -- Supported Apple Desktop Bus (/dev/adb) - -- Supported Coda network file system (/dev/cfs*) -=============================================================================== -Changes for patch v44 - -- Fixed devfs inode leak when manually recreating inodes - -- Fixed permission persistence problem when recreating inodes -=============================================================================== -Changes for patch v45 - -- Ported to kernel 2.1.110 -=============================================================================== -Changes for patch v46 - -- Ported to kernel 2.1.112-pre1 - -- Removed harmless "unused variable" compiler warning - -- Fixed modes for manually recreated device nodes -=============================================================================== -Changes for patch v47 - -- Added NULL devfs inode warning in - -- Force all inode nlink values to 1 -=============================================================================== -Changes for patch v48 - -- Added "dimknod" option - -- Set inode nlink to 0 when freeing dentries - -- Added support for virtual console capture devices (/dev/vcs*) - Thanks to Dennis Hou - -- Fixed modes for manually recreated symlinks -=============================================================================== -Changes for patch v49 - -- Ported to kernel 2.1.113 -=============================================================================== -Changes for patch v50 - -- Fixed bugs in recreated directories and symlinks -=============================================================================== -Changes for patch v51 - -- Improved robustness of rc.devfs script - Thanks to Roderich Schupp - -- Fixed bugs in recreated device nodes - -- Fixed bug in currently unused - -- Defined new type - -- Improved debugging when getting entries - -- Fixed bug where directories could be emptied - -- Ported to kernel 2.1.115 -=============================================================================== -Changes for patch v52 - -- Replaced dummy .epoch inode with .devfsd character device - -- Modified rc.devfs to take account of above change - -- Removed spurious driver warning messages when CONFIG_DEVFS_FS=n - -- Implemented devfsd protocol revision 0 -=============================================================================== -Changes for patch v53 - -- Ported to kernel 2.1.116 (kmod change broke hunk) - -- Updated Documentation/Configure.help - -- Test and tty pattern patch for rc.devfs script - Thanks to Roderich Schupp - -- Added soothing message to warning in -=============================================================================== -Changes for patch v54 - -- Ported to kernel 2.1.117 - -- Fixed default permissions in sound driver - -- Added support for frame buffer devices (/dev/fb*) -=============================================================================== -Changes for patch v55 - -- Ported to kernel 2.1.119 - -- Use GCC extensions for structure initialisations - -- Implemented async open notification - -- Incremented devfsd protocol revision to 1 -=============================================================================== -Changes for patch v56 - -- Ported to kernel 2.1.120-pre3 - -- Moved async open notification to end of -=============================================================================== -Changes for patch v57 - -- Ported to kernel 2.1.121 - -- Prepended "/dev/" to module load request - -- Renamed to - -- Created sample modules.conf file -=============================================================================== -Changes for patch v58 - -- Fixed typo "AYSNC" -> "ASYNC" -=============================================================================== -Changes for patch v59 - -- Added open flag for files -=============================================================================== -Changes for patch v60 - -- Ported to kernel 2.1.123-pre2 -=============================================================================== -Changes for patch v61 - -- Set i_blocks=0 and i_blksize=1024 in -=============================================================================== -Changes for patch v62 - -- Ported to kernel 2.1.123 -=============================================================================== -Changes for patch v63 - -- Ported to kernel 2.1.124-pre2 -=============================================================================== -Changes for patch v64 - -- Fixed Unix98 pty support - -- Increased buffer size in to avoid crash and - burn -=============================================================================== -Changes for patch v65 - -- More Unix98 pty support fixes - -- Added test for empty <> in - -- Renamed to and published - -- Created /dev/root symlink - Thanks to Roderich Schupp - with further modifications by me -=============================================================================== -Changes for patch v66 - -- Yet more Unix98 pty support fixes (now tested) - -- Created - -- Support media change checks when CONFIG_DEVFS_ONLY=y - -- Abolished Unix98-style PTY names for old PTY devices -=============================================================================== -Changes for patch v67 - -- Added inline declaration for dummy - -- Removed spurious "unable to register... in devfs" messages when - CONFIG_DEVFS_FS=n - -- Fixed misc. devices when CONFIG_DEVFS_FS=n - -- Limit auto-device numbering to majors 144 to 239 -=============================================================================== -Changes for patch v68 - -- Hide unopened virtual consoles from directory listings - -- Added support for video capture devices - -- Ported to kernel 2.1.125 -=============================================================================== -Changes for patch v69 - -- Fix for CONFIG_VT=n -=============================================================================== -Changes for patch v70 - -- Added support for non-OSS/Free sound cards -=============================================================================== -Changes for patch v71 - -- Ported to kernel 2.1.126-pre2 -=============================================================================== -Changes for patch v72 - -- #ifdef's for CONFIG_DEVFS_DISABLE_OLD_NAMES removed -=============================================================================== -Changes for patch v73 - -- CONFIG_DEVFS_DISABLE_OLD_NAMES replaced with "nocompat" boot option - -- CONFIG_DEVFS_BOOT_OPTIONS removed: boot options always available -=============================================================================== -Changes for patch v74 - -- Removed CONFIG_DEVFS_MOUNT and "mount" boot option and replaced with - "nomount" boot option - -- Documentation updates - -- Updated sample modules.conf -=============================================================================== -Changes for patch v75 - -- Updated sample modules.conf - -- Remount devfs after initrd finishes - -- Ported to kernel 2.1.127 - -- Added support for ISDN - Thanks to Christophe Leroy -=============================================================================== -Changes for patch v76 - -- Updated an email address in ChangeLog - -- CONFIG_DEVFS_ONLY replaced with "only" boot option -=============================================================================== -Changes for patch v77 - -- Added DEVFS_FL_REMOVABLE flag - -- Check for disc change when listing directories with removable media - devices - -- Use DEVFS_FL_REMOVABLE in sd.c - -- Ported to kernel 2.1.128 -=============================================================================== -Changes for patch v78 - -- Only call on first call to - -- Ported to kernel 2.1.129-pre5 - -- ISDN support improvements - Thanks to Christophe Leroy -=============================================================================== -Changes for patch v79 - -- Ported to kernel 2.1.130 - -- Renamed miscdevice "apm" to "apm_bios" to be consistent with - devices.txt -=============================================================================== -Changes for patch v80 - -- Ported to kernel 2.1.131 - -- Updated for VFS change in 2.1.131 -=============================================================================== -Changes for patch v81 - -- Fixed permissions on /dev/ptmx -=============================================================================== -Changes for patch v82 - -- Ported to kernel 2.1.132-pre4 - -- Changed initial permissions on /dev/pts/* - -- Created - -- Added "symlinks" boot option - -- Changed devfs_register_blkdev() back to register_blkdev() for IDE - -- Check for partitions on removable media in -=============================================================================== -Changes for patch v83 - -- Fixed support for ramdisc when using string-based root FS name - -- Ported to kernel 2.2.0-pre1 -=============================================================================== -Changes for patch v84 - -- Ported to kernel 2.2.0-pre7 -=============================================================================== -Changes for patch v85 - -- Compile fixes for driver/sound/sound_common.c (non-module) and - drivers/isdn/isdn_common.c - Thanks to Christophe Leroy - -- Added support for registering regular files - -- Created - -- Added /dev/cpu/mtrr as an alternative interface to /proc/mtrr - -- Update devfs inodes from entries if not changed through FS -=============================================================================== -Changes for patch v86 - -- Ported to kernel 2.2.0-pre9 -=============================================================================== -Changes for patch v87 - -- Fixed bug when mounting non-devfs devices in a devfs -=============================================================================== -Changes for patch v88 - -- Fixed to only initialise temporary inodes - -- Trap for NULL fops in - -- Return -ENODEV in for non-driver inodes - -- Fixed bug when unswapping non-devfs devices in a devfs -=============================================================================== -Changes for patch v89 - -- Switched to C data types in include/linux/devfs_fs.h - -- Switched from PATH_MAX to DEVFS_PATHLEN - -- Updated Documentation/filesystems/devfs/modules.conf to take account - of reverse scanning (!) by modprobe - -- Ported to kernel 2.2.0 -=============================================================================== -Changes for patch v90 - -- CONFIG_DEVFS_DISABLE_OLD_TTY_NAMES replaced with "nottycompat" boot - option - -- CONFIG_DEVFS_TTY_COMPAT removed: existing "symlinks" boot option now - controls this. This means you must have libc 5.4.44 or later, or a - recent version of libc 6 if you use the "symlinks" option -=============================================================================== -Changes for patch v91 - -- Switch from to in - drivers/char/vc_screen.c to fix problems with Midnight Commander -=============================================================================== -Changes for patch v92 - -- Ported to kernel 2.2.2-pre5 -=============================================================================== -Changes for patch v93 - -- Modified in drivers/scsi/sd.c to cope with devices that - don't exist (which happens with new RAID autostart code printk()s) -=============================================================================== -Changes for patch v94 - -- Fixed bug in joystick driver: only first joystick was registered -=============================================================================== -Changes for patch v95 - -- Fixed another bug in joystick driver - -- Fixed to not overrun event buffer -=============================================================================== -Changes for patch v96 - -- Ported to kernel 2.2.5-2 - -- Created - -- Fixed bugs: compatibility entries were not unregistered for: - loop driver - floppy driver - RAMDISC driver - IDE tape driver - SCSI CD-ROM driver - SCSI HDD driver -=============================================================================== -Changes for patch v97 - -- Fixed bugs: compatibility entries were not unregistered for: - ALSA sound driver - partitions in generic disc driver - -- Don't return unregistred entries in - -- Panic in if entry unregistered - -- Don't panic in for duplicates -=============================================================================== -Changes for patch v98 - -- Don't unregister already unregistered entries in - -- Register entry in - -- Unregister entry in - -- Changed to in drivers/char/tty_io.c - -- Ported to kernel 2.2.7 -=============================================================================== -Changes for patch v99 - -- Ported to kernel 2.2.8 - -- Fixed bug in drivers/scsi/sd.c when >16 SCSI discs - -- Disable warning messages when unable to read partition table for - removable media -=============================================================================== -Changes for patch v100 - -- Ported to kernel 2.3.1-pre5 - -- Added "oops-on-panic" boot option - -- Improved debugging in and - -- Register entry in - -- Unregister entry in - -- Register entry in - -- Unregister entry in - -- Added support for ALSA drivers -=============================================================================== -Changes for patch v101 - -- Ported to kernel 2.3.2 -=============================================================================== -Changes for patch v102 - -- Update serial driver to register PCMCIA entries - Thanks to Roch-Alexandre Nomine-Beguin - -- Updated an email address in ChangeLog - -- Hide virtual console capture entries from directory listings when - corresponding console device is not open -=============================================================================== -Changes for patch v103 - -- Ported to kernel 2.3.3 -=============================================================================== -Changes for patch v104 - -- Added documentation for some functions - -- Added "doc" target to fs/devfs/Makefile - -- Added "v4l" directory for video4linux devices - -- Replaced call to in with call to - - -- Moved registration for sr and sg drivers from detect() to attach() - methods - -- Register entries in and unregister in - -- Work around IDE driver treating CD-ROM as gendisk - -- Use instead of in rc.devfs - -- Updated ToDo list - -- Removed "oops-on-panic" boot option: now always Oops -=============================================================================== -Changes for patch v105 - -- Unregister SCSI host from in - Thanks to Zoltán Böszörményi - -- Don't save /dev/log in rc.devfs - -- Ported to kernel 2.3.4-pre1 -=============================================================================== -Changes for patch v106 - -- Fixed silly typo in drivers/scsi/st.c - -- Improved debugging in -=============================================================================== -Changes for patch v107 - -- Added "diunlink" and "nokmod" boot options - -- Removed superfluous warning message in -=============================================================================== -Changes for patch v108 - -- Remove entries when unloading sound module -=============================================================================== -Changes for patch v109 - -- Ported to kernel 2.3.6-pre2 -=============================================================================== -Changes for patch v110 - -- Took account of change to -=============================================================================== -Changes for patch v111 - -- Created separate event queue for each mounted devfs - -- Removed - -- Created new ioctl()s for devfsd - -- Incremented devfsd protocol revision to 3 - -- Fixed bug when re-creating directories: contents were lost - -- Block access to inodes until devfsd updates permissions -=============================================================================== -Changes for patch v112 - -- Modified patch so it applies against 2.3.5 and 2.3.6 - -- Updated an email address in ChangeLog - -- Do not automatically change ownership/protection of /dev/tty - -- Updated sample modules.conf - -- Switched to sending process uid/gid to devfsd - -- Renamed to - -- Added DEVFSD_NOTIFY_LOOKUP event - -- Added DEVFSD_NOTIFY_CHANGE event - -- Added DEVFSD_NOTIFY_CREATE event - -- Incremented devfsd protocol revision to 4 - -- Moved kernel-specific stuff to include/linux/devfs_fs_kernel.h -=============================================================================== -Changes for patch v113 - -- Ported to kernel 2.3.9 - -- Restricted permissions on some block devices -=============================================================================== -Changes for patch v114 - -- Added support for /dev/netlink - Thanks to Dennis Hou - -- Return EISDIR rather than EINVAL for read(2) on directories - -- Ported to kernel 2.3.10 -=============================================================================== -Changes for patch v115 - -- Added support for all remaining character devices - Thanks to Dennis Hou - -- Cleaned up netlink support -=============================================================================== -Changes for patch v116 - -- Added support for /dev/parport%d - Thanks to Tim Waugh - -- Fixed parallel port ATAPI tape driver - -- Fixed Atari SLM laser printer driver -=============================================================================== -Changes for patch v117 - -- Added support for COSA card - Thanks to Dennis Hou - -- Fixed drivers/char/ppdev.c: missing #include - -- Fixed drivers/char/ftape/zftape/zftape-init.c - Thanks to Vladimir Popov -=============================================================================== -Changes for patch v118 - -- Ported to kernel 2.3.15-pre3 - -- Fixed bug in loop driver - -- Unregister /dev/lp%d entries in drivers/char/lp.c - Thanks to Maciej W. Rozycki -=============================================================================== -Changes for patch v119 - -- Ported to kernel 2.3.16 -=============================================================================== -Changes for patch v120 - -- Fixed bug in drivers/scsi/scsi.c - -- Added /dev/ppp - Thanks to Dennis Hou - -- Ported to kernel 2.3.17 -=============================================================================== -Changes for patch v121 - -- Fixed bug in drivers/block/loop.c - -- Ported to kernel 2.3.18 -=============================================================================== -Changes for patch v122 - -- Ported to kernel 2.3.19 -=============================================================================== -Changes for patch v123 - -- Ported to kernel 2.3.20 -=============================================================================== -Changes for patch v124 - -- Ported to kernel 2.3.21 -=============================================================================== -Changes for patch v125 - -- Created , , - and - Added <> parameter to , , - and - Work sponsored by SGI - -- Fixed apparent bug in COSA driver - -- Re-instated "scsihosts=" boot option -=============================================================================== -Changes for patch v126 - -- Always create /dev/pts if CONFIG_UNIX98_PTYS=y - -- Fixed call to in drivers/block/ide-disk.c - Thanks to Dennis Hou - -- Allow multiple unregistrations - -- Created /dev/scsi hierarchy - Work sponsored by SGI -=============================================================================== -Changes for patch v127 - -Work sponsored by SGI - -- No longer disable devpts if devfs enabled (caveat emptor) - -- Added flags array to struct gendisk and removed code from - drivers/scsi/sd.c - -- Created /dev/discs hierarchy -=============================================================================== -Changes for patch v128 - -Work sponsored by SGI - -- Created /dev/cdroms hierarchy -=============================================================================== -Changes for patch v129 - -Work sponsored by SGI - -- Removed compatibility entries for sound devices - -- Removed compatibility entries for printer devices - -- Removed compatibility entries for video4linux devices - -- Removed compatibility entries for parallel port devices - -- Removed compatibility entries for frame buffer devices -=============================================================================== -Changes for patch v130 - -Work sponsored by SGI - -- Added major and minor number to devfsd protocol - -- Incremented devfsd protocol revision to 5 - -- Removed compatibility entries for SoundBlaster CD-ROMs - -- Removed compatibility entries for netlink devices - -- Removed compatibility entries for SCSI generic devices - -- Removed compatibility entries for SCSI tape devices -=============================================================================== -Changes for patch v131 - -Work sponsored by SGI - -- Support info pointer for all devfs entry types - -- Added <> parameter to and - -- Removed /dev/st hierarchy - -- Removed /dev/sg hierarchy - -- Removed compatibility entries for loop devices - -- Removed compatibility entries for IDE tape devices - -- Removed compatibility entries for SCSI CD-ROMs - -- Removed /dev/sr hierarchy -=============================================================================== -Changes for patch v132 - -Work sponsored by SGI - -- Removed compatibility entries for floppy devices - -- Removed compatibility entries for RAMDISCs - -- Removed compatibility entries for meta-devices - -- Removed compatibility entries for SCSI discs - -- Created - -- Removed /dev/sd hierarchy - -- Support "../" when searching devfs namespace - -- Created /dev/ide/host* hierarchy - -- Supported IDE hard discs in /dev/ide/host* hierarchy - -- Removed compatibility entries for IDE discs - -- Removed /dev/ide/hd hierarchy - -- Supported IDE CD-ROMs in /dev/ide/host* hierarchy - -- Removed compatibility entries for IDE CD-ROMs - -- Removed /dev/ide/cd hierarchy -=============================================================================== -Changes for patch v133 - -Work sponsored by SGI - -- Created - -- Fixed bug in fs/partitions/check.c when rescanning -=============================================================================== -Changes for patch v134 - -Work sponsored by SGI - -- Removed /dev/sd, /dev/sr, /dev/st and /dev/sg directories - -- Removed /dev/ide/hd directory - -- Exported - -- Created and /dev/tapes hierarchy - -- Removed /dev/ide/mt hierarchy - -- Removed /dev/ide/fd hierarchy - -- Ported to kernel 2.3.25 -=============================================================================== -Changes for patch v135 - -Work sponsored by SGI - -- Removed compatibility entries for virtual console capture devices - -- Removed unused - -- Removed compatibility entries for serial devices - -- Removed compatibility entries for console devices - -- Do not hide entries from devfsd or children - -- Removed DEVFS_FL_TTY_COMPAT flag - -- Removed "nottycompat" boot option - -- Removed -=============================================================================== -Changes for patch v136 - -Work sponsored by SGI - -- Moved BSD pty devices to /dev/pty - -- Added DEVFS_FL_WAIT flag -=============================================================================== -Changes for patch v137 - -Work sponsored by SGI - -- Really fixed bug in fs/partitions/check.c when rescanning - -- Support new "disc" naming scheme in - -- Allow NULL fops in - -- Removed redundant name functions in SCSI disc and IDE drivers -=============================================================================== -Changes for patch v138 - -Work sponsored by SGI - -- Fixed old bugs in drivers/block/paride/pt.c, drivers/char/tpqic02.c, - drivers/net/wan/cosa.c and drivers/scsi/scsi.c - Thanks to Sergey Kubushin - -- Fall back to major table if NULL fops given to -=============================================================================== -Changes for patch v139 - -Work sponsored by SGI - -- Corrected and moved and declarations - from arch/alpha/kernel/osf_sys.c to include/linux/fs.h - -- Removed name function from struct gendisk - -- Updated devfs FAQ -=============================================================================== -Changes for patch v140 - -Work sponsored by SGI - -- Ported to kernel 2.3.27 -=============================================================================== -Changes for patch v141 - -Work sponsored by SGI - -- Bug fix in arch/m68k/atari/joystick.c - -- Moved ISDN and capi devices to /dev/isdn -=============================================================================== -Changes for patch v142 - -Work sponsored by SGI - -- Bug fix in drivers/block/ide-probe.c (patch confusion) -=============================================================================== -Changes for patch v143 - -Work sponsored by SGI - -- Bug fix in drivers/block/blkpg.c:partition_name() -=============================================================================== -Changes for patch v144 - -Work sponsored by SGI - -- Ported to kernel 2.3.29 - -- Removed calls to from cdu31a, cm206, mcd and mcdx - CD-ROM drivers: generic driver handles this now - -- Moved joystick devices to /dev/joysticks -=============================================================================== -Changes for patch v145 - -Work sponsored by SGI - -- Ported to kernel 2.3.30-pre3 - -- Register whole-disc entry even for invalid partition tables - -- Fixed bug in mounting root FS when initrd enabled - -- Fixed device entry leak with IDE CD-ROMs - -- Fixed compile problem with drivers/isdn/isdn_common.c - -- Moved COSA devices to /dev/cosa - -- Support fifos when unregistering - -- Created and used in many drivers - -- Moved Coda devices to /dev/coda - -- Moved parallel port IDE tapes to /dev/pt - -- Moved parallel port IDE generic devices to /dev/pg -=============================================================================== -Changes for patch v146 - -Work sponsored by SGI - -- Removed obsolete DEVFS_FL_COMPAT and DEVFS_FL_TOLERANT flags - -- Fixed compile problem with fs/coda/psdev.c - -- Reinstate change to in - drivers/block/ide-probe.c now that fs/isofs/inode.c is fixed - -- Switched to in drivers/block/floppy.c, - drivers/scsi/sr.c and drivers/block/md.c - -- Moved DAC960 devices to /dev/dac960 -=============================================================================== -Changes for patch v147 - -Work sponsored by SGI - -- Ported to kernel 2.3.32-pre4 -=============================================================================== -Changes for patch v148 - -Work sponsored by SGI - -- Removed kmod support: use devfsd instead - -- Moved miscellaneous character devices to /dev/misc -=============================================================================== -Changes for patch v149 - -Work sponsored by SGI - -- Ensure include/linux/joystick.h is OK for user-space - -- Improved debugging in - -- Ensure dentries created by devfsd will be cleaned up -=============================================================================== -Changes for patch v150 - -Work sponsored by SGI - -- Ported to kernel 2.3.34 -=============================================================================== -Changes for patch v151 - -Work sponsored by SGI - -- Ported to kernel 2.3.35-pre1 - -- Created -=============================================================================== -Changes for patch v152 - -Work sponsored by SGI - -- Updated sample modules.conf - -- Ported to kernel 2.3.36-pre1 -=============================================================================== -Changes for patch v153 - -Work sponsored by SGI - -- Ported to kernel 2.3.42 - -- Removed -=============================================================================== -Changes for patch v154 - -Work sponsored by SGI - -- Took account of device number changes for /dev/fb* -=============================================================================== -Changes for patch v155 - -Work sponsored by SGI - -- Ported to kernel 2.3.43-pre8 - -- Moved /dev/tty0 to /dev/vc/0 - -- Moved sequence number formatting from <_tty_make_name> to drivers -=============================================================================== -Changes for patch v156 - -Work sponsored by SGI - -- Fixed breakage in drivers/scsi/sd.c due to recent SCSI changes -=============================================================================== -Changes for patch v157 - -Work sponsored by SGI - -- Ported to kernel 2.3.45 -=============================================================================== -Changes for patch v158 - -Work sponsored by SGI - -- Ported to kernel 2.3.46-pre2 -=============================================================================== -Changes for patch v159 - -Work sponsored by SGI - -- Fixed drivers/block/md.c - Thanks to Mike Galbraith - -- Documentation fixes - -- Moved device registration from to - Thanks to Tim Waugh -=============================================================================== -Changes for patch v160 - -Work sponsored by SGI - -- Fixed drivers/char/joystick/joystick.c - Thanks to Vojtech Pavlik - -- Documentation updates - -- Fixed arch/i386/kernel/mtrr.c if procfs and devfs not enabled - -- Fixed drivers/char/stallion.c -=============================================================================== -Changes for patch v161 - -Work sponsored by SGI - -- Remove /dev/ide when ide-mod is unloaded - -- Fixed bug in drivers/block/ide-probe.c when secondary but no primary - -- Added DEVFS_FL_NO_PERSISTENCE flag - -- Used new DEVFS_FL_NO_PERSISTENCE flag for Unix98 pty slaves - -- Removed unnecessary call to in - - -- Only set auto-ownership for /dev/pty/s* -=============================================================================== -Changes for patch v162 - -Work sponsored by SGI - -- Set inode->i_size to correct size for symlinks - Thanks to Jeremy Fitzhardinge - -- Only give lookup() method to directories to comply with new VFS - assumptions - -- Remove unnecessary tests in symlink methods - -- Don't kill existing block ops in - -- Restore auto-ownership for /dev/pty/m* -=============================================================================== -Changes for patch v163 - -Work sponsored by SGI - -- Don't create missing directories in - -- Removed Documentation/filesystems/devfs/mk-devlinks - -- Updated Documentation/filesystems/devfs/README -=============================================================================== -Changes for patch v164 - -Work sponsored by SGI - -- Fixed CONFIG_DEVFS breakage in drivers/char/serial.c introduced in - linux-2.3.99-pre6-7 -=============================================================================== -Changes for patch v165 - -Work sponsored by SGI - -- Ported to kernel 2.3.99-pre6 -=============================================================================== -Changes for patch v166 - -Work sponsored by SGI - -- Added CONFIG_DEVFS_MOUNT -=============================================================================== -Changes for patch v167 - -Work sponsored by SGI - -- Updated Documentation/filesystems/devfs/README - -- Updated sample modules.conf -=============================================================================== -Changes for patch v168 - -Work sponsored by SGI - -- Disabled multi-mount capability (use VFS bindings instead) - -- Updated README from master HTML file -=============================================================================== -Changes for patch v169 - -Work sponsored by SGI - -- Removed multi-mount code - -- Removed compatibility macros: VFS has changed too much -=============================================================================== -Changes for patch v170 - -Work sponsored by SGI - -- Updated README from master HTML file - -- Merged devfs inode into devfs entry -=============================================================================== -Changes for patch v171 - -Work sponsored by SGI - -- Updated sample modules.conf - -- Removed dead code in which used to call - - -- Ported to kernel 2.4.0-test2-pre3 -=============================================================================== -Changes for patch v172 - -Work sponsored by SGI - -- Changed interface to - -- Changed interface to -=============================================================================== -Changes for patch v173 - -Work sponsored by SGI - -- Simplified interface to - -- Simplified interface to - -- Simplified interface to -=============================================================================== -Changes for patch v174 - -Work sponsored by SGI - -- Updated README from master HTML file -=============================================================================== -Changes for patch v175 - -Work sponsored by SGI - -- DocBook update for fs/devfs/base.c - Thanks to Tim Waugh - -- Removed stale fs/tunnel.c (was never used or completed) -=============================================================================== -Changes for patch v176 - -Work sponsored by SGI - -- Updated ToDo list - -- Removed sample modules.conf: now distributed with devfsd - -- Updated README from master HTML file - -- Ported to kernel 2.4.0-test3-pre4 (which had devfs-patch-v174) -=============================================================================== -Changes for patch v177 - -- Updated README from master HTML file - -- Documentation cleanups - -- Ensure terminates string for root entry - Thanks to Tim Jansen - -- Exported to modules - -- Make send events to devfsd - -- Cleaned up option processing in - -- Fixed bugs in handling symlinks: could leak or cause Oops - -- Cleaned up directory handling by separating fops - Thanks to Alexander Viro -=============================================================================== -Changes for patch v178 - -- Fixed handling of inverted options in -=============================================================================== -Changes for patch v179 - -- Adjusted to account for fix -=============================================================================== -Changes for patch v180 - -- Fixed !CONFIG_DEVFS_FS stub declaration of -=============================================================================== -Changes for patch v181 - -- Answered question posed by Al Viro and removed his comments from - -- Moved setting of registered flag after other fields are changed - -- Fixed race between and - -- Global VFS changes added bogus BKL to devfsd_close(): removed - -- Widened locking in and - -- Replaced stack usage with kmalloc - -- Simplified locking in and fixed memory leak -=============================================================================== -Changes for patch v182 - -- Created and - -- Removed broken devnum allocation and use - -- Fixed old devnum leak by calling new - -- Created - -- Fixed number leak for /dev/cdroms/cdrom%d - -- Fixed number leak for /dev/discs/disc%d -=============================================================================== -Changes for patch v183 - -- Fixed bug in which could hang boot process -=============================================================================== -Changes for patch v184 - -- Documentation typo fix for fs/devfs/util.c - -- Fixed drivers/char/stallion.c for devfs - -- Added DEVFSD_NOTIFY_DELETE event - -- Updated README from master HTML file - -- Removed #include from fs/devfs/base.c -=============================================================================== -Changes for patch v185 - -- Made and in fs/devfs/util.c - private - -- Fixed inode table races by removing it and using inode->u.generic_ip - instead - -- Moved into - -- Moved into -=============================================================================== -Changes for patch v186 - -- Fixed race in for uni-processor - -- Updated README from master HTML file -=============================================================================== -Changes for patch v187 - -- Fixed drivers/char/stallion.c for devfs - -- Fixed drivers/char/rocket.c for devfs - -- Fixed bug in : limited to 128 numbers -=============================================================================== -Changes for patch v188 - -- Updated major masks in fs/devfs/util.c up to Linus' "no new majors" - proclamation. Block: were 126 now 122 free, char: were 26 now 19 free - -- Updated README from master HTML file - -- Removed remnant of multi-mount support in - -- Removed unused DEVFS_FL_SHOW_UNREG flag -=============================================================================== -Changes for patch v189 - -- Removed nlink field from struct devfs_inode - -- Removed auto-ownership for /dev/pty/* (BSD ptys) and used - DEVFS_FL_CURRENT_OWNER|DEVFS_FL_NO_PERSISTENCE for /dev/pty/s* (just - like Unix98 pty slaves) and made /dev/pty/m* rw-rw-rw- access -=============================================================================== -Changes for patch v190 - -- Updated README from master HTML file - -- Replaced BKL with global rwsem to protect symlink data (quick and - dirty hack) -=============================================================================== -Changes for patch v191 - -- Replaced global rwsem for symlink with per-link refcount -=============================================================================== -Changes for patch v192 - -- Removed unnecessary #ifdef CONFIG_DEVFS_FS from arch/i386/kernel/mtrr.c - -- Ported to kernel 2.4.10-pre11 - -- Set inode->i_mapping->a_ops for block nodes in -=============================================================================== -Changes for patch v193 - -- Went back to global rwsem for symlinks (refcount scheme no good) -=============================================================================== -Changes for patch v194 - -- Fixed overrun in by removing function (not needed) - -- Updated README from master HTML file -=============================================================================== -Changes for patch v195 - -- Fixed buffer underrun in - -- Moved down_read() from to -=============================================================================== -Changes for patch v196 - -- Fixed race in when setting event mask - Thanks to Kari Hurtta - -- Avoid deadlock in by using temporary buffer -=============================================================================== -Changes for patch v197 - -- First release of new locking code for devfs core (v1.0) - -- Fixed bug in drivers/cdrom/cdrom.c -=============================================================================== -Changes for patch v198 - -- Discard temporary buffer, now use "%s" for dentry names - -- Don't generate path in : use fake entry instead - -- Use "existing" directory in <_devfs_make_parent_for_leaf> - -- Use slab cache rather than fixed buffer for devfsd events -=============================================================================== -Changes for patch v199 - -- Removed obsolete usage of DEVFS_FL_NO_PERSISTENCE - -- Send DEVFSD_NOTIFY_REGISTERED events in - -- Fixed locking bug in due to typo - -- Do not send CREATE, CHANGE, ASYNC_OPEN or DELETE events from devfsd - or children -=============================================================================== -Changes for patch v200 - -- Ported to kernel 2.5.1-pre2 -=============================================================================== -Changes for patch v201 - -- Fixed bug in : was dereferencing freed pointer -=============================================================================== -Changes for patch v202 - -- Fixed bug in : was dereferencing freed pointer - -- Added process group check for devfsd privileges -=============================================================================== -Changes for patch v203 - -- Use SLAB_ATOMIC in from -=============================================================================== -Changes for patch v204 - -- Removed long obsolete rc.devfs - -- Return old entry in for 2.4.x kernels - -- Updated README from master HTML file - -- Increment refcount on module in - -- Created and exported - -- Increment refcount on module in - -- Created and used where needed to fix races - -- Added clarifying comments in response to preliminary EMC code review - -- Added poisoning to - -- Improved debugging messages - -- Fixed unregister bugs in drivers/md/lvm-fs.c -=============================================================================== -Changes for patch v205 - -- Corrected (made useful) debugging message in - -- Moved in to - -- Fixed drivers/md/lvm-fs.c to create "lvm" entry - -- Added magic number to guard against scribbling drivers - -- Only return old entry in if a directory - -- Defined macros for error and debug messages - -- Updated README from master HTML file -=============================================================================== -Changes for patch v206 - -- Added support for multiple Compaq cpqarray controllers - -- Fixed (rare, old) race in -=============================================================================== -Changes for patch v207 - -- Fixed deadlock bug in - -- Tag VFS deletable in if handle ignored - -- Updated README from master HTML file -=============================================================================== -Changes for patch v208 - -- Added KERN_* to remaining messages - -- Cleaned up declaration of - -- Updated README from master HTML file -=============================================================================== -Changes for patch v209 - -- Updated README from master HTML file - -- Removed silently introduced calls to lock_kernel() and - unlock_kernel() due to recent VFS locking changes. BKL isn't - required in devfs - -- Changed to allow later additions if not yet empty - -- Added calls to in drivers/block/blkpc.c - and - -- Fixed bug in : was clearing beyond - bitfield - -- Fixed bitfield data type for - -- Made major bitfield type and initialiser 64 bit safe -=============================================================================== -Changes for patch v210 - -- Updated fs/devfs/util.c to fix shift warning on 64 bit machines - Thanks to Anton Blanchard - -- Updated README from master HTML file -=============================================================================== -Changes for patch v211 - -- Do not put miscellaneous character devices in /dev/misc if they - specify their own directory (i.e. contain a '/' character) - -- Copied macro for error messages from fs/devfs/base.c to - fs/devfs/util.c and made use of this macro - -- Removed 2.4.x compatibility code from fs/devfs/base.c -=============================================================================== -Changes for patch v212 - -- Added BKL to because drivers still need it -=============================================================================== -Changes for patch v213 - -- Protected and - from changing directory contents -=============================================================================== -Changes for patch v214 - -- Switched to ISO C structure field initialisers - -- Switch to set_current_state() and move before add_wait_queue() - -- Updated README from master HTML file - -- Fixed devfs entry leak in when *readdir fails -=============================================================================== -Changes for patch v215 - -- Created - -- Switched many functions from to - - -- Switched many functions from to -=============================================================================== -Changes for patch v216 - -- Switched arch/ia64/sn/io/hcl.c from to - - -- Removed deprecated -=============================================================================== -Changes for patch v217 - -- Exported and to modules - -- Updated README from master HTML file - -- Fixed module unload race in -=============================================================================== -Changes for patch v218 - -- Removed DEVFS_FL_AUTO_OWNER flag - -- Switched lingering structure field initialiser to ISO C - -- Added locking when setting/clearing flags - -- Documentation fix in fs/devfs/util.c diff --git a/Documentation/filesystems/devfs/README b/Documentation/filesystems/devfs/README deleted file mode 100644 index aabfba24bc2..00000000000 --- a/Documentation/filesystems/devfs/README +++ /dev/null @@ -1,1959 +0,0 @@ -Devfs (Device File System) FAQ - - -Linux Devfs (Device File System) FAQ -Richard Gooch -20-AUG-2002 - - -Document languages: - - - - - - - ------------------------------------------------------------------------------ - -NOTE: the master copy of this document is available online at: - -http://www.atnf.csiro.au/~rgooch/linux/docs/devfs.html -and looks much better than the text version distributed with the -kernel sources. A mirror site is available at: - -http://www.ras.ucalgary.ca/~rgooch/linux/docs/devfs.html - -There is also an optional daemon that may be used with devfs. You can -find out more about it at: - -http://www.atnf.csiro.au/~rgooch/linux/ - -A mailing list is available which you may subscribe to. Send -email -to majordomo@oss.sgi.com with the following line in the -body of the message: -subscribe devfs -To unsubscribe, send the message body: -unsubscribe devfs -instead. The list is archived at - -http://oss.sgi.com/projects/devfs/archive/. - ------------------------------------------------------------------------------ - -Contents - - -What is it? - -Why do it? - -Who else does it? - -How it works - -Operational issues (essential reading) - -Instructions for the impatient -Permissions persistence across reboots -Dealing with drivers without devfs support -All the way with Devfs -Other Issues -Kernel Naming Scheme -Devfsd Naming Scheme -Old Compatibility Names -SCSI Host Probing Issues - - - -Device drivers currently ported - -Allocation of Device Numbers - -Questions and Answers - -Making things work -Alternatives to devfs -What I don't like about devfs -How to report bugs -Strange kernel messages -Compilation problems with devfsd - - -Other resources - -Translations of this document - - ------------------------------------------------------------------------------ - - -What is it? - -Devfs is an alternative to "real" character and block special devices -on your root filesystem. Kernel device drivers can register devices by -name rather than major and minor numbers. These devices will appear in -devfs automatically, with whatever default ownership and -protection the driver specified. A daemon (devfsd) can be used to -override these defaults. Devfs has been in the kernel since 2.3.46. - -NOTE that devfs is entirely optional. If you prefer the old -disc-based device nodes, then simply leave CONFIG_DEVFS_FS=n (the -default). In this case, nothing will change. ALSO NOTE that if you do -enable devfs, the defaults are such that full compatibility is -maintained with the old devices names. - -There are two aspects to devfs: one is the underlying device -namespace, which is a namespace just like any mounted filesystem. The -other aspect is the filesystem code which provides a view of the -device namespace. The reason I make a distinction is because devfs -can be mounted many times, with each mount showing the same device -namespace. Changes made are global to all mounted devfs filesystems. -Also, because the devfs namespace exists without any devfs mounts, you -can easily mount the root filesystem by referring to an entry in the -devfs namespace. - - -The cost of devfs is a small increase in kernel code size and memory -usage. About 7 pages of code (some of that in __init sections) and 72 -bytes for each entry in the namespace. A modest system has only a -couple of hundred device entries, so this costs a few more -pages. Compare this with the suggestion to put /dev on a ramdisc. - -On a typical machine, the cost is under 0.2 percent. On a modest -system with 64 MBytes of RAM, the cost is under 0.1 percent. The -accusations of "bloatware" levelled at devfs are not justified. - ------------------------------------------------------------------------------ - - -Why do it? - -There are several problems that devfs addresses. Some of these -problems are more serious than others (depending on your point of -view), and some can be solved without devfs. However, the totality of -these problems really calls out for devfs. - -The choice is a patchwork of inefficient user space solutions, which -are complex and likely to be fragile, or to use a simple and efficient -devfs which is robust. - -There have been many counter-proposals to devfs, all seeking to -provide some of the benefits without actually implementing devfs. So -far there has been an absence of code and no proposed alternative has -been able to provide all the features that devfs does. Further, -alternative proposals require far more complexity in user-space (and -still deliver less functionality than devfs). Some people have the -mantra of reducing "kernel bloat", but don't consider the effects on -user-space. - -A good solution limits the total complexity of kernel-space and -user-space. - - -Major&minor allocation - -The existing scheme requires the allocation of major and minor device -numbers for each and every device. This means that a central -co-ordinating authority is required to issue these device numbers -(unless you're developing a "private" device driver), in order to -preserve uniqueness. Devfs shifts the burden to a namespace. This may -not seem like a huge benefit, but actually it is. Since driver authors -will naturally choose a device name which reflects the functionality -of the device, there is far less potential for namespace conflict. -Solving this requires a kernel change. - -/dev management - -Because you currently access devices through device nodes, these must -be created by the system administrator. For standard devices you can -usually find a MAKEDEV programme which creates all these (hundreds!) -of nodes. This means that changes in the kernel must be reflected by -changes in the MAKEDEV programme, or else the system administrator -creates device nodes by hand. - -The basic problem is that there are two separate databases of -major and minor numbers. One is in the kernel and one is in /dev (or -in a MAKEDEV programme, if you want to look at it that way). This is -duplication of information, which is not good practice. -Solving this requires a kernel change. - -/dev growth - -A typical /dev has over 1200 nodes! Most of these devices simply don't -exist because the hardware is not available. A huge /dev increases the -time to access devices (I'm just referring to the dentry lookup times -and the time taken to read inodes off disc: the next subsection shows -some more horrors). - -An example of how big /dev can grow is if we consider SCSI devices: - -host 6 bits (say up to 64 hosts on a really big machine) -channel 4 bits (say up to 16 SCSI buses per host) -id 4 bits -lun 3 bits -partition 6 bits -TOTAL 23 bits - - -This requires 8 Mega (1024*1024) inodes if we want to store all -possible device nodes. Even if we scrap everything but id,partition -and assume a single host adapter with a single SCSI bus and only one -logical unit per SCSI target (id), that's still 10 bits or 1024 -inodes. Each VFS inode takes around 256 bytes (kernel 2.1.78), so -that's 256 kBytes of inode storage on disc (assuming real inodes take -a similar amount of space as VFS inodes). This is actually not so bad, -because disc is cheap these days. Embedded systems would care about -256 kBytes of /dev inodes, but you could argue that embedded systems -would have hand-tuned /dev directories. I've had to do just that on my -embedded systems, but I would rather just leave it to devfs. - -Another issue is the time taken to lookup an inode when first -referenced. Not only does this take time in scanning through a list in -memory, but also the seek times to read the inodes off disc. -This could be solved in user-space using a clever programme which -scanned the kernel logs and deleted /dev entries which are not -available and created them when they were available. This programme -would need to be run every time a new module was loaded, which would -slow things down a lot. - -There is an existing programme called scsidev which will automatically -create device nodes for SCSI devices. It can do this by scanning files -in /proc/scsi. Unfortunately, to extend this idea to other device -nodes would require significant modifications to existing drivers (so -they too would provide information in /proc). This is a non-trivial -change (I should know: devfs has had to do something similar). Once -you go to this much effort, you may as well use devfs itself (which -also provides this information). Furthermore, such a system would -likely be implemented in an ad-hoc fashion, as different drivers will -provide their information in different ways. - -Devfs is much cleaner, because it (naturally) has a uniform mechanism -to provide this information: the device nodes themselves! - - -Node to driver file_operations translation - -There is an important difference between the way disc-based character -and block nodes and devfs entries make the connection between an entry -in /dev and the actual device driver. - -With the current 8 bit major and minor numbers the connection between -disc-based c&b nodes and per-major drivers is done through a -fixed-length table of 128 entries. The various filesystem types set -the inode operations for c&b nodes to {chr,blk}dev_inode_operations, -so when a device is opened a few quick levels of indirection bring us -to the driver file_operations. - -For miscellaneous character devices a second step is required: there -is a scan for the driver entry with the same minor number as the file -that was opened, and the appropriate minor open method is called. This -scanning is done *every time* you open a device node. Potentially, you -may be searching through dozens of misc. entries before you find your -open method. While not an enormous performance overhead, this does -seem pointless. - -Linux *must* move beyond the 8 bit major and minor barrier, -somehow. If we simply increase each to 16 bits, then the indexing -scheme used for major driver lookup becomes untenable, because the -major tables (one each for character and block devices) would need to -be 64 k entries long (512 kBytes on x86, 1 MByte for 64 bit -systems). So we would have to use a scheme like that used for -miscellaneous character devices, which means the search time goes up -linearly with the average number of major device drivers on your -system. Not all "devices" are hardware, some are higher-level drivers -like KGI, so you can get more "devices" without adding hardware -You can improve this by creating an ordered (balanced:-) -binary tree, in which case your search time becomes log(N). -Alternatively, you can use hashing to speed up the search. -But why do that search at all if you don't have to? Once again, it -seems pointless. - -Note that devfs doesn't use the major&minor system. For devfs -entries, the connection is done when you lookup the /dev entry. When -devfs_register() is called, an internal table is appended which has -the entry name and the file_operations. If the dentry cache doesn't -have the /dev entry already, this internal table is scanned to get the -file_operations, and an inode is created. If the dentry cache already -has the entry, there is *no lookup time* (other than the dentry scan -itself, but we can't avoid that anyway, and besides Linux dentries -cream other OS's which don't have them:-). Furthermore, the number of -node entries in a devfs is only the number of available device -entries, not the number of *conceivable* entries. Even if you remove -unnecessary entries in a disc-based /dev, the number of conceivable -entries remains the same: you just limit yourself in order to save -space. - -Devfs provides a fast connection between a VFS node and the device -driver, in a scalable way. - -/dev as a system administration tool - -Right now /dev contains a list of conceivable devices, most of which I -don't have. Devfs only shows those devices available on my -system. This means that listing /dev is a handy way of checking what -devices are available. - -Major&minor size - -Existing major and minor numbers are limited to 8 bits each. This is -now a limiting factor for some drivers, particularly the SCSI disc -driver, which consumes a single major number. Only 16 discs are -supported, and each disc may have only 15 partitions. Maybe this isn't -a problem for you, but some of us are building huge Linux systems with -disc arrays. With devfs an arbitrary pointer can be associated with -each device entry, which can be used to give an effective 32 bit -device identifier (i.e. that's like having a 32 bit minor -number). Since this is private to the kernel, there are no C library -compatibility issues which you would have with increasing major and -minor number sizes. See the section on "Allocation of Device Numbers" -for details on maintaining compatibility with userspace. - -Solving this requires a kernel change. - -Since writing this, the kernel has been modified so that the SCSI disc -driver has more major numbers allocated to it and now supports up to -128 discs. Since these major numbers are non-contiguous (a result of -unplanned expansion), the implementation is a little more cumbersome -than originally. - -Just like the changes to IPv4 to fix impending limitations in the -address space, people find ways around the limitations. In the long -run, however, solutions like IPv6 or devfs can't be put off forever. - -Read-only root filesystem - -Having your device nodes on the root filesystem means that you can't -operate properly with a read-only root filesystem. This is because you -want to change ownerships and protections of tty devices. Existing -practice prevents you using a CD-ROM as your root filesystem for a -*real* system. Sure, you can boot off a CD-ROM, but you can't change -tty ownerships, so it's only good for installing. - -Also, you can't use a shared NFS root filesystem for a cluster of -discless Linux machines (having tty ownerships changed on a common -/dev is not good). Nor can you embed your root filesystem in a -ROM-FS. - -You can get around this by creating a RAMDISC at boot time, making -an ext2 filesystem in it, mounting it somewhere and copying the -contents of /dev into it, then unmounting it and mounting it over -/dev. - -A devfs is a cleaner way of solving this. - -Non-Unix root filesystem - -Non-Unix filesystems (such as NTFS) can't be used for a root -filesystem because they variously don't support character and block -special files or symbolic links. You can't have a separate disc-based -or RAMDISC-based filesystem mounted on /dev because you need device -nodes before you can mount these. Devfs can be mounted without any -device nodes. Devlinks won't work because symlinks aren't supported. -An alternative solution is to use initrd to mount a RAMDISC initial -root filesystem (which is populated with a minimal set of device -nodes), and then construct a new /dev in another RAMDISC, and finally -switch to your non-Unix root filesystem. This requires clever boot -scripts and a fragile and conceptually complex boot procedure. - -Devfs solves this in a robust and conceptually simple way. - -PTY security - -Current pseudo-tty (pty) devices are owned by root and read-writable -by everyone. The user of a pty-pair cannot change -ownership/protections without being suid-root. - -This could be solved with a secure user-space daemon which runs as -root and does the actual creation of pty-pairs. Such a daemon would -require modification to *every* programme that wants to use this new -mechanism. It also slows down creation of pty-pairs. - -An alternative is to create a new open_pty() syscall which does much -the same thing as the user-space daemon. Once again, this requires -modifications to pty-handling programmes. - -The devfs solution allows a device driver to "tag" certain device -files so that when an unopened device is opened, the ownerships are -changed to the current euid and egid of the opening process, and the -protections are changed to the default registered by the driver. When -the device is closed ownership is set back to root and protections are -set back to read-write for everybody. No programme need be changed. -The devpts filesystem provides this auto-ownership feature for Unix98 -ptys. It doesn't support old-style pty devices, nor does it have all -the other features of devfs. - -Intelligent device management - -Devfs implements a simple yet powerful protocol for communication with -a device management daemon (devfsd) which runs in user space. It is -possible to send a message (either synchronously or asynchronously) to -devfsd on any event, such as registration/unregistration of device -entries, opening and closing devices, looking up inodes, scanning -directories and more. This has many possibilities. Some of these are -already implemented. See: - - -http://www.atnf.csiro.au/~rgooch/linux/ - -Device entry registration events can be used by devfsd to change -permissions of newly-created device nodes. This is one mechanism to -control device permissions. - -Device entry registration/unregistration events can be used to run -programmes or scripts. This can be used to provide automatic mounting -of filesystems when a new block device media is inserted into the -drive. - -Asynchronous device open and close events can be used to implement -clever permissions management. For example, the default permissions on -/dev/dsp do not allow everybody to read from the device. This is -sensible, as you don't want some remote user recording what you say at -your console. However, the console user is also prevented from -recording. This behaviour is not desirable. With asynchronous device -open and close events, you can have devfsd run a programme or script -when console devices are opened to change the ownerships for *other* -device nodes (such as /dev/dsp). On closure, you can run a different -script to restore permissions. An advantage of this scheme over -modifying the C library tty handling is that this works even if your -programme crashes (how many times have you seen the utmp database with -lingering entries for non-existent logins?). - -Synchronous device open events can be used to perform intelligent -device access protections. Before the device driver open() method is -called, the daemon must first validate the open attempt, by running an -external programme or script. This is far more flexible than access -control lists, as access can be determined on the basis of other -system conditions instead of just the UID and GID. - -Inode lookup events can be used to authenticate module autoload -requests. Instead of using kmod directly, the event is sent to -devfsd which can implement an arbitrary authentication before loading -the module itself. - -Inode lookup events can also be used to construct arbitrary -namespaces, without having to resort to populating devfs with symlinks -to devices that don't exist. - -Speculative Device Scanning - -Consider an application (like cdparanoia) that wants to find all -CD-ROM devices on the system (SCSI, IDE and other types), whether or -not their respective modules are loaded. The application must -speculatively open certain device nodes (such as /dev/sr0 for the SCSI -CD-ROMs) in order to make sure the module is loaded. This requires -that all Linux distributions follow the standard device naming scheme -(last time I looked RedHat did things differently). Devfs solves the -naming problem. - -The same application also wants to see which devices are actually -available on the system. With the existing system it needs to read the -/dev directory and speculatively open each /dev/sr* device to -determine if the device exists or not. With a large /dev this is an -inefficient operation, especially if there are many /dev/sr* nodes. A -solution like scsidev could reduce the number of /dev/sr* entries (but -of course that also requires all that inefficient directory scanning). - -With devfs, the application can open the /dev/sr directory -(which triggers the module autoloading if required), and proceed to -read /dev/sr. Since only the available devices will have -entries, there are no inefficencies in directory scanning or device -openings. - ------------------------------------------------------------------------------ - -Who else does it? - -FreeBSD has a devfs implementation. Solaris and AIX each have a -pseudo-devfs (something akin to scsidev but for all devices, with some -unspecified kernel support). BeOS, Plan9 and QNX also have it. SGI's -IRIX 6.4 and above also have a device filesystem. - -While we shouldn't just automatically do something because others do -it, we should not ignore the work of others either. FreeBSD has a lot -of competent people working on it, so their opinion should not be -blithely ignored. - ------------------------------------------------------------------------------ - - -How it works - -Registering device entries - -For every entry (device node) in a devfs-based /dev a driver must call -devfs_register(). This adds the name of the device entry, the -file_operations structure pointer and a few other things to an -internal table. Device entries may be added and removed at any -time. When a device entry is registered, it automagically appears in -any mounted devfs'. - -Inode lookup - -When a lookup operation on an entry is performed and if there is no -driver information for that entry devfs will attempt to call -devfsd. If still no driver information can be found then a negative -dentry is yielded and the next stage operation will be called by the -VFS (such as create() or mknod() inode methods). If driver information -can be found, an inode is created (if one does not exist already) and -all is well. - -Manually creating device nodes - -The mknod() method allows you to create an ordinary named pipe in the -devfs, or you can create a character or block special inode if one -does not already exist. You may wish to create a character or block -special inode so that you can set permissions and ownership. Later, if -a device driver registers an entry with the same name, the -permissions, ownership and times are retained. This is how you can set -the protections on a device even before the driver is loaded. Once you -create an inode it appears in the directory listing. - -Unregistering device entries - -A device driver calls devfs_unregister() to unregister an entry. - -Chroot() gaols - -2.2.x kernels - -The semantics of inode creation are different when devfs is mounted -with the "explicit" option. Now, when a device entry is registered, it -will not appear until you use mknod() to create the device. It doesn't -matter if you mknod() before or after the device is registered with -devfs_register(). The purpose of this behaviour is to support -chroot(2) gaols, where you want to mount a minimal devfs inside the -gaol. Only the devices you specifically want to be available (through -your mknod() setup) will be accessible. - -2.4.x kernels - -As of kernel 2.3.99, the VFS has had the ability to rebind parts of -the global filesystem namespace into another part of the namespace. -This now works even at the leaf-node level, which means that -individual files and device nodes may be bound into other parts of the -namespace. This is like making links, but better, because it works -across filesystems (unlike hard links) and works through chroot() -gaols (unlike symbolic links). - -Because of these improvements to the VFS, the multi-mount capability -in devfs is no longer needed. The administrator may create a minimal -device tree inside a chroot(2) gaol by using VFS bindings. As this -provides most of the features of the devfs multi-mount capability, I -removed the multi-mount support code (after issuing an RFC). This -yielded code size reductions and simplifications. - -If you want to construct a minimal chroot() gaol, the following -command should suffice: - -mount --bind /dev/null /gaol/dev/null - - -Repeat for other device nodes you want to expose. Simple! - ------------------------------------------------------------------------------ - - -Operational issues - - -Instructions for the impatient - -Nobody likes reading documentation. People just want to get in there -and play. So this section tells you quickly the steps you need to take -to run with devfs mounted over /dev. Skip these steps and you will end -up with a nearly unbootable system. Subsequent sections describe the -issues in more detail, and discuss non-essential configuration -options. - -Devfsd -OK, if you're reading this, I assume you want to play with -devfs. First you should ensure that /usr/src/linux contains a -recent kernel source tree. Then you need to compile devfsd, the device -management daemon, available at - -http://www.atnf.csiro.au/~rgooch/linux/. -Because the kernel has a naming scheme -which is quite different from the old naming scheme, you need to -install devfsd so that software and configuration files that use the -old naming scheme will not break. - -Compile and install devfsd. You will be provided with a default -configuration file /etc/devfsd.conf which will provide -compatibility symlinks for the old naming scheme. Don't change this -config file unless you know what you're doing. Even if you think you -do know what you're doing, don't change it until you've followed all -the steps below and booted a devfs-enabled system and verified that it -works. - -Now edit your main system boot script so that devfsd is started at the -very beginning (before any filesystem -checks). /etc/rc.d/rc.sysinit is often the main boot script -on systems with SysV-style boot scripts. On systems with BSD-style -boot scripts it is often /etc/rc. Also check -/sbin/rc. - -NOTE that the line you put into the boot -script should be exactly: - -/sbin/devfsd /dev - -DO NOT use some special daemon-launching -programme, otherwise the boot script may not wait for devfsd to finish -initialising. - -System Libraries -There may still be some problems because of broken software making -assumptions about device names. In particular, some software does not -handle devices which are symbolic links. If you are running a libc 5 -based system, install libc 5.4.44 (if you have libc 5.4.46, go back to -libc 5.4.44, which is actually correct). If you are running a glibc -based system, make sure you have glibc 2.1.3 or later. - -/etc/securetty -PAM (Pluggable Authentication Modules) is supposed to be a flexible -mechanism for providing better user authentication and access to -services. Unfortunately, it's also fragile, complex and undocumented -(check out RedHat 6.1, and probably other distributions as well). PAM -has problems with symbolic links. Append the following lines to your -/etc/securetty file: - -vc/1 -vc/2 -vc/3 -vc/4 -vc/5 -vc/6 -vc/7 -vc/8 - -This will not weaken security. If you have a version of util-linux -earlier than 2.10.h, please upgrade to 2.10.h or later. If you -absolutely cannot upgrade, then also append the following lines to -your /etc/securetty file: - -1 -2 -3 -4 -5 -6 -7 -8 - -This may potentially weaken security by allowing root logins over the -network (a password is still required, though). However, since there -are problems with dealing with symlinks, I'm suspicious of the level -of security offered in any case. - -XFree86 -While not essential, it's probably a good idea to upgrade to XFree86 -4.0, as patches went in to make it more devfs-friendly. If you don't, -you'll probably need to apply the following patch to -/etc/security/console.perms so that ordinary users can run -startx. Note that not all distributions have this file (e.g. Debian), -so if it's not present, don't worry about it. - ---- /etc/security/console.perms.orig Sat Apr 17 16:26:47 1999 -+++ /etc/security/console.perms Fri Feb 25 23:53:55 2000 -@@ -14,7 +14,7 @@ - # man 5 console.perms - - # file classes -- these are regular expressions --=tty[0-9][0-9]* :[0-9]\.[0-9] :[0-9] -+=tty[0-9][0-9]* vc/[0-9][0-9]* :[0-9]\.[0-9] :[0-9] - - # device classes -- these are shell-style globs - =/dev/fd[0-1]* - -If the patch does not apply, then change the line: - -=tty[0-9][0-9]* :[0-9]\.[0-9] :[0-9] - -with: - -=tty[0-9][0-9]* vc/[0-9][0-9]* :[0-9]\.[0-9] :[0-9] - - -Disable devpts -I've had a report of devpts mounted on /dev/pts not working -correctly. Since devfs will also manage /dev/pts, there is no -need to mount devpts as well. You should either edit your -/etc/fstab so devpts is not mounted, or disable devpts from -your kernel configuration. - -Unsupported drivers -Not all drivers have devfs support. If you depend on one of these -drivers, you will need to create a script or tarfile that you can use -at boot time to create device nodes as appropriate. There is a -section which describes this. Another -section lists the drivers which have -devfs support. - -/dev/mouse - -Many disributions configure /dev/mouse to be the mouse device -for XFree86 and GPM. I actually think this is a bad idea, because it -adds another level of indirection. When looking at a config file, if -you see /dev/mouse you're left wondering which mouse -is being referred to. Hence I recommend putting the actual mouse -device (for example /dev/psaux) into your -/etc/X11/XF86Config file (and similarly for the GPM -configuration file). - -Alternatively, use the same technique used for unsupported drivers -described above. - -The Kernel -Finally, you need to make sure devfs is compiled into your kernel. Set -CONFIG_EXPERIMENTAL=y, CONFIG_DEVFS_FS=y and CONFIG_DEVFS_MOUNT=y by -using favourite configuration tool (i.e. make config or -make xconfig) and then make clean and then recompile your kernel and -modules. At boot, devfs will be mounted onto /dev. - -If you encounter problems booting (for example if you forgot a -configuration step), you can pass devfs=nomount at the kernel -boot command line. This will prevent the kernel from mounting devfs at -boot time onto /dev. - -In general, a kernel built with CONFIG_DEVFS_FS=y but without mounting -devfs onto /dev is completely safe, and requires no -configuration changes. One exception to take note of is when -LABEL= directives are used in /etc/fstab. In this -case you will be unable to boot properly. This is because the -mount(8) programme uses /proc/partitions as part of -the volume label search process, and the device names it finds are not -available, because setting CONFIG_DEVFS_FS=y changes the names in -/proc/partitions, irrespective of whether devfs is mounted. - -Now you've finished all the steps required. You're now ready to boot -your shiny new kernel. Enjoy. - -Changing the configuration - -OK, you've now booted a devfs-enabled system, and everything works. -Now you may feel like changing the configuration (common targets are -/etc/fstab and /etc/devfsd.conf). Since you have a -system that works, if you make any changes and it doesn't work, you -now know that you only have to restore your configuration files to the -default and it will work again. - - -Permissions persistence across reboots - -If you don't use mknod(2) to create a device file, nor use chmod(2) or -chown(2) to change the ownerships/permissions, the inode ctime will -remain at 0 (the epoch, 12 am, 1-JAN-1970, GMT). Anything with a ctime -later than this has had it's ownership/permissions changed. Hence, a -simple script or programme may be used to tar up all changed inodes, -prior to shutdown. Although effective, many consider this approach a -kludge. - -A much better approach is to use devfsd to save and restore -permissions. It may be configured to record changes in permissions and -will save them in a database (in fact a directory tree), and restore -these upon boot. This is an efficient method and results in immediate -saving of current permissions (unlike the tar approach, which saves -permissions at some unspecified future time). - -The default configuration file supplied with devfsd has config entries -which you may uncomment to enable persistence management. - -If you decide to use the tar approach anyway, be aware that tar will -first unlink(2) an inode before creating a new device node. The -unlink(2) has the effect of breaking the connection between a devfs -entry and the device driver. If you use the "devfs=only" boot option, -you lose access to the device driver, requiring you to reload the -module. I consider this a bug in tar (there is no real need to -unlink(2) the inode first). - -Alternatively, you can use devfsd to provide more sophisticated -management of device permissions. You can use devfsd to store -permissions for whole groups of devices with a single configuration -entry, rather than the conventional single entry per device entry. - -Permissions database stored in mounted-over /dev - -If you wish to save and restore your device permissions into the -disc-based /dev while still mounting devfs onto /dev -you may do so. This requires a 2.4.x kernel (in fact, 2.3.99 or -later), which has the VFS binding facility. You need to do the -following to set this up: - - - -make sure the kernel does not mount devfs at boot time - - -make sure you have a correct /dev/console entry in your -root file-system (where your disc-based /dev lives) - -create the /dev-state directory - - -add the following lines near the very beginning of your boot -scripts: - -mount --bind /dev /dev-state -mount -t devfs none /dev -devfsd /dev - - - - -add the following lines to your /etc/devfsd.conf file: - -REGISTER ^pt[sy] IGNORE -CREATE ^pt[sy] IGNORE -CHANGE ^pt[sy] IGNORE -DELETE ^pt[sy] IGNORE -REGISTER .* COPY /dev-state/$devname $devpath -CREATE .* COPY $devpath /dev-state/$devname -CHANGE .* COPY $devpath /dev-state/$devname -DELETE .* CFUNCTION GLOBAL unlink /dev-state/$devname -RESTORE /dev-state - -Note that the sample devfsd.conf file contains these lines, -as well as other sample configurations you may find useful. See the -devfsd distribution - - -reboot. - - - - -Permissions database stored in normal directory - -If you are using an older kernel which doesn't support VFS binding, -then you won't be able to have the permissions database in a -mounted-over /dev. However, you can still use a regular -directory to store the database. The sample /etc/devfsd.conf -file above may still be used. You will need to create the -/dev-state directory prior to installing devfsd. If you have -old permissions in /dev, then just copy (or move) the device -nodes over to the new directory. - -Which method is better? - -The best method is to have the permissions database stored in the -mounted-over /dev. This is because you will not need to copy -device nodes over to /dev-state, and because it allows you to -switch between devfs and non-devfs kernels, without requiring you to -copy permissions between /dev-state (for devfs) and -/dev (for non-devfs). - - -Dealing with drivers without devfs support - -Currently, not all device drivers in the kernel have been modified to -use devfs. Device drivers which do not yet have devfs support will not -automagically appear in devfs. The simplest way to create device nodes -for these drivers is to unpack a tarfile containing the required -device nodes. You can do this in your boot scripts. All your drivers -will now work as before. - -Hopefully for most people devfs will have enough support so that they -can mount devfs directly over /dev without losing most functionality -(i.e. losing access to various devices). As of 22-JAN-1998 (devfs -patch version 10) I am now running this way. All the devices I have -are available in devfs, so I don't lose anything. - -WARNING: if your configuration requires the old-style device names -(i.e. /dev/hda1 or /dev/sda1), you must install devfsd and configure -it to maintain compatibility entries. It is almost certain that you -will require this. Note that the kernel creates a compatibility entry -for the root device, so you don't need initrd. - -Note that you no longer need to mount devpts if you use Unix98 PTYs, -as devfs can manage /dev/pts itself. This saves you some RAM, as you -don't need to compile and install devpts. Note that some versions of -glibc have a bug with Unix98 pty handling on devfs systems. Contact -the glibc maintainers for a fix. Glibc 2.1.3 has the fix. - -Note also that apart from editing /etc/fstab, other things will need -to be changed if you *don't* install devfsd. Some software (like the X -server) hard-wire device names in their source. It really is much -easier to install devfsd so that compatibility entries are created. -You can then slowly migrate your system to using the new device names -(for example, by starting with /etc/fstab), and then limiting the -compatibility entries that devfsd creates. - -IF YOU CONFIGURE TO MOUNT DEVFS AT BOOT, MAKE SURE YOU INSTALL DEVFSD -BEFORE YOU BOOT A DEVFS-ENABLED KERNEL! - -Now that devfs has gone into the 2.3.46 kernel, I'm getting a lot of -reports back. Many of these are because people are trying to run -without devfsd, and hence some things break. Please just run devfsd if -things break. I want to concentrate on real bugs rather than -misconfiguration problems at the moment. If people are willing to fix -bugs/false assumptions in other code (i.e. glibc, X server) and submit -that to the respective maintainers, that would be great. - - -All the way with Devfs - -The devfs kernel patch creates a rationalised device tree. As stated -above, if you want to keep using the old /dev naming scheme, -you just need to configure devfsd appopriately (see the man -page). People who prefer the old names can ignore this section. For -those of us who like the rationalised names and an uncluttered -/dev, read on. - -If you don't run devfsd, or don't enable compatibility entry -management, then you will have to configure your system to use the new -names. For example, you will then need to edit your -/etc/fstab to use the new disc naming scheme. If you want to -be able to boot non-devfs kernels, you will need compatibility -symlinks in the underlying disc-based /dev pointing back to -the old-style names for when you boot a kernel without devfs. - -You can selectively decide which devices you want compatibility -entries for. For example, you may only want compatibility entries for -BSD pseudo-terminal devices (otherwise you'll have to patch you C -library or use Unix98 ptys instead). It's just a matter of putting in -the correct regular expression into /dev/devfsd.conf. - -There are other choices of naming schemes that you may prefer. For -example, I don't use the kernel-supplied -names, because they are too verbose. A common misconception is -that the kernel-supplied names are meant to be used directly in -configuration files. This is not the case. They are designed to -reflect the layout of the devices attached and to provide easy -classification. - -If you like the kernel-supplied names, that's fine. If you don't then -you should be using devfsd to construct a namespace more to your -liking. Devfsd has built-in code to construct a -namespace that is both logical and easy to -manage. In essence, it creates a convenient abbreviation of the -kernel-supplied namespace. - -You are of course free to build your own namespace. Devfsd has all the -infrastructure required to make this easy for you. All you need do is -write a script. You can even write some C code and devfsd can load the -shared object as a callable extension. - - -Other Issues - -The init programme -Another thing to take note of is whether your init programme -creates a Unix socket /dev/telinit. Some versions of init -create /dev/telinit so that the telinit programme can -communicate with the init process. If you have such a system you need -to make sure that devfs is mounted over /dev *before* init -starts. In other words, you can't leave the mounting of devfs to -/etc/rc, since this is executed after init. Other -versions of init require a named pipe /dev/initctl -which must exist *before* init starts. Once again, you need to -mount devfs and then create the named pipe *before* init -starts. - -The default behaviour now is not to mount devfs onto /dev at -boot time for 2.3.x and later kernels. You can correct this with the -"devfs=mount" boot option. This solves any problems with init, -and also prevents the dreaded: - -Cannot open initial console - -message. For 2.2.x kernels where you need to apply the devfs patch, -the default is to mount. - -If you have automatic mounting of devfs onto /dev then you -may need to create /dev/initctl in your boot scripts. The -following lines should suffice: - -mknod /dev/initctl p -kill -SIGUSR1 1 # tell init that /dev/initctl now exists - -Alternatively, if you don't want the kernel to mount devfs onto -/dev then you could use the following procedure is a -guideline for how to get around /dev/initctl problems: - -# cd /sbin -# mv init init.real -# cat > init -#! /bin/sh -mount -n -t devfs none /dev -mknod /dev/initctl p -exec /sbin/init.real $* -[control-D] -# chmod a+x init - -Note that newer versions of init create /dev/initctl -automatically, so you don't have to worry about this. - -Module autoloading -You will need to configure devfsd to enable module -autoloading. The following lines should be placed in your -/etc/devfsd.conf file: - -LOOKUP .* MODLOAD - - -As of devfsd-v1.3.10, a generic /etc/modules.devfs -configuration file is installed, which is used by the MODLOAD -action. This should be sufficient for most configurations. If you -require further configuration, edit your /etc/modules.conf -file. The way module autoloading work with devfs is: - - -a process attempts to lookup a device node (e.g. /dev/fred) - - -if that device node does not exist, the full pathname is passed to -devfsd as a string - - -devfsd will pass the string to the modprobe programme (provided the -configuration line shown above is present), and specifies that -/etc/modules.devfs is the configuration file - - -/etc/modules.devfs includes /etc/modules.conf to -access local configurations - -modprobe will search it's configuration files, looking for an alias -that translates the pathname into a module name - - -the translated pathname is then used to load the module. - - -If you wanted a lookup of /dev/fred to load the -mymod module, you would require the following configuration -line in /etc/modules.conf: - -alias /dev/fred mymod - -The /etc/modules.devfs configuration file provides many such -aliases for standard device names. If you look closely at this file, -you will note that some modules require multiple alias configuration -lines. This is required to support module autoloading for old and new -device names. - -Mounting root off a devfs device -If you wish to mount root off a devfs device when you pass the -"devfs=only" boot option, then you need to pass in the -"root=" option to the kernel when booting. If you use -LILO, then you must have this in lilo.conf: - -append = "root=" - -Surprised? Yep, so was I. It turns out if you have (as most people -do): - -root = - - -then LILO will determine the device number of and will -write that device number into a special place in the kernel image -before starting the kernel, and the kernel will use that device number -to mount the root filesystem. So, using the "append" variety ensures -that LILO passes the root filesystem device as a string, which devfs -can then use. - -Note that this isn't an issue if you don't pass "devfs=only". - -TTY issues -The ttyname(3) function in some versions of the C library makes -false assumptions about device entries which are symbolic links. The -tty(1) programme is one that depends on this function. I've -written a patch to libc 5.4.43 which fixes this. This has been -included in libc 5.4.44 and a similar fix is in glibc 2.1.3. - - -Kernel Naming Scheme - -The kernel provides a default naming scheme. This scheme is designed -to make it easy to search for specific devices or device types, and to -view the available devices. Some device types (such as hard discs), -have a directory of entries, making it easy to see what devices of -that class are available. Often, the entries are symbolic links into a -directory tree that reflects the topology of available devices. The -topological tree is useful for finding how your devices are arranged. - -Below is a list of the naming schemes for the most common drivers. A -list of reserved device names is -available for reference. Please send email to -rgooch@atnf.csiro.au to obtain an allocation. Please be -patient (the maintainer is busy). An alternative name may be allocated -instead of the requested name, at the discretion of the maintainer. - -Disc Devices - -All discs, whether SCSI, IDE or whatever, are placed under the -/dev/discs hierarchy: - - /dev/discs/disc0 first disc - /dev/discs/disc1 second disc - - -Each of these entries is a symbolic link to the directory for that -device. The device directory contains: - - disc for the whole disc - part* for individual partitions - - -CD-ROM Devices - -All CD-ROMs, whether SCSI, IDE or whatever, are placed under the -/dev/cdroms hierarchy: - - /dev/cdroms/cdrom0 first CD-ROM - /dev/cdroms/cdrom1 second CD-ROM - - -Each of these entries is a symbolic link to the real device entry for -that device. - -Tape Devices - -All tapes, whether SCSI, IDE or whatever, are placed under the -/dev/tapes hierarchy: - - /dev/tapes/tape0 first tape - /dev/tapes/tape1 second tape - - -Each of these entries is a symbolic link to the directory for that -device. The device directory contains: - - mt for mode 0 - mtl for mode 1 - mtm for mode 2 - mta for mode 3 - mtn for mode 0, no rewind - mtln for mode 1, no rewind - mtmn for mode 2, no rewind - mtan for mode 3, no rewind - - -SCSI Devices - -To uniquely identify any SCSI device requires the following -information: - - controller (host adapter) - bus (SCSI channel) - target (SCSI ID) - unit (Logical Unit Number) - - -All SCSI devices are placed under /dev/scsi (assuming devfs -is mounted on /dev). Hence, a SCSI device with the following -parameters: c=1,b=2,t=3,u=4 would appear as: - - /dev/scsi/host1/bus2/target3/lun4 device directory - - -Inside this directory, a number of device entries may be created, -depending on which SCSI device-type drivers were installed. - -See the section on the disc naming scheme to see what entries the SCSI -disc driver creates. - -See the section on the tape naming scheme to see what entries the SCSI -tape driver creates. - -The SCSI CD-ROM driver creates: - - cd - - -The SCSI generic driver creates: - - generic - - -IDE Devices - -To uniquely identify any IDE device requires the following -information: - - controller - bus (aka. primary/secondary) - target (aka. master/slave) - unit - - -All IDE devices are placed under /dev/ide, and uses a similar -naming scheme to the SCSI subsystem. - -XT Hard Discs - -All XT discs are placed under /dev/xd. The first XT disc has -the directory /dev/xd/disc0. - -TTY devices - -The tty devices now appear as: - - New name Old-name Device Type - -------- -------- ----------- - /dev/tts/{0,1,...} /dev/ttyS{0,1,...} Serial ports - /dev/cua/{0,1,...} /dev/cua{0,1,...} Call out devices - /dev/vc/0 /dev/tty Current virtual console - /dev/vc/{1,2,...} /dev/tty{1...63} Virtual consoles - /dev/vcc/{0,1,...} /dev/vcs{1...63} Virtual consoles - /dev/pty/m{0,1,...} /dev/ptyp?? PTY masters - /dev/pty/s{0,1,...} /dev/ttyp?? PTY slaves - - -RAMDISCS - -The RAMDISCS are placed in their own directory, and are named thus: - - /dev/rd/{0,1,2,...} - - -Meta Devices - -The meta devices are placed in their own directory, and are named -thus: - - /dev/md/{0,1,2,...} - - -Floppy discs - -Floppy discs are placed in the /dev/floppy directory. - -Loop devices - -Loop devices are placed in the /dev/loop directory. - -Sound devices - -Sound devices are placed in the /dev/sound directory -(audio, sequencer, ...). - - -Devfsd Naming Scheme - -Devfsd provides a naming scheme which is a convenient abbreviation of -the kernel-supplied namespace. In some -cases, the kernel-supplied naming scheme is quite convenient, so -devfsd does not provide another naming scheme. The convenience names -that devfsd creates are in fact the same names as the original devfs -kernel patch created (before Linus mandated the Big Name -Change). These are referred to as "new compatibility entries". - -In order to configure devfsd to create these convenience names, the -following lines should be placed in your /etc/devfsd.conf: - -REGISTER .* MKNEWCOMPAT -UNREGISTER .* RMNEWCOMPAT - -This will cause devfsd to create (and destroy) symbolic links which -point to the kernel-supplied names. - -SCSI Hard Discs - -All SCSI discs are placed under /dev/sd (assuming devfs is -mounted on /dev). Hence, a SCSI disc with the following -parameters: c=1,b=2,t=3,u=4 would appear as: - - /dev/sd/c1b2t3u4 for the whole disc - /dev/sd/c1b2t3u4p5 for the 5th partition - /dev/sd/c1b2t3u4p5s6 for the 6th slice in the 5th partition - - -SCSI Tapes - -All SCSI tapes are placed under /dev/st. A similar naming -scheme is used as for SCSI discs. A SCSI tape with the -parameters:c=1,b=2,t=3,u=4 would appear as: - - /dev/st/c1b2t3u4m0 for mode 0 - /dev/st/c1b2t3u4m1 for mode 1 - /dev/st/c1b2t3u4m2 for mode 2 - /dev/st/c1b2t3u4m3 for mode 3 - /dev/st/c1b2t3u4m0n for mode 0, no rewind - /dev/st/c1b2t3u4m1n for mode 1, no rewind - /dev/st/c1b2t3u4m2n for mode 2, no rewind - /dev/st/c1b2t3u4m3n for mode 3, no rewind - - -SCSI CD-ROMs - -All SCSI CD-ROMs are placed under /dev/sr. A similar naming -scheme is used as for SCSI discs. A SCSI CD-ROM with the -parameters:c=1,b=2,t=3,u=4 would appear as: - - /dev/sr/c1b2t3u4 - - -SCSI Generic Devices - -The generic (aka. raw) interface for all SCSI devices are placed under -/dev/sg. A similar naming scheme is used as for SCSI discs. A -SCSI generic device with the parameters:c=1,b=2,t=3,u=4 would appear -as: - - /dev/sg/c1b2t3u4 - - -IDE Hard Discs - -All IDE discs are placed under /dev/ide/hd, using a similar -convention to SCSI discs. The following mappings exist between the new -and the old names: - - /dev/hda /dev/ide/hd/c0b0t0u0 - /dev/hdb /dev/ide/hd/c0b0t1u0 - /dev/hdc /dev/ide/hd/c0b1t0u0 - /dev/hdd /dev/ide/hd/c0b1t1u0 - - -IDE Tapes - -A similar naming scheme is used as for IDE discs. The entries will -appear in the /dev/ide/mt directory. - -IDE CD-ROM - -A similar naming scheme is used as for IDE discs. The entries will -appear in the /dev/ide/cd directory. - -IDE Floppies - -A similar naming scheme is used as for IDE discs. The entries will -appear in the /dev/ide/fd directory. - -XT Hard Discs - -All XT discs are placed under /dev/xd. The first XT disc -would appear as /dev/xd/c0t0. - - -Old Compatibility Names - -The old compatibility names are the legacy device names, such as -/dev/hda, /dev/sda, /dev/rtc and so on. -Devfsd can be configured to create compatibility symlinks so that you -may continue to use the old names in your configuration files and so -that old applications will continue to function correctly. - -In order to configure devfsd to create these legacy names, the -following lines should be placed in your /etc/devfsd.conf: - -REGISTER .* MKOLDCOMPAT -UNREGISTER .* RMOLDCOMPAT - -This will cause devfsd to create (and destroy) symbolic links which -point to the kernel-supplied names. - - ------------------------------------------------------------------------------ - - -Device drivers currently ported - -- All miscellaneous character devices support devfs (this is done - transparently through misc_register()) - -- SCSI discs and generic hard discs - -- Character memory devices (null, zero, full and so on) - Thanks to C. Scott Ananian - -- Loop devices (/dev/loop?) - -- TTY devices (console, serial ports, terminals and pseudo-terminals) - Thanks to C. Scott Ananian - -- SCSI tapes (/dev/scsi and /dev/tapes) - -- SCSI CD-ROMs (/dev/scsi and /dev/cdroms) - -- SCSI generic devices (/dev/scsi) - -- RAMDISCS (/dev/ram?) - -- Meta Devices (/dev/md*) - -- Floppy discs (/dev/floppy) - -- Parallel port printers (/dev/printers) - -- Sound devices (/dev/sound) - Thanks to Eric Dumas and - C. Scott Ananian - -- Joysticks (/dev/joysticks) - -- Sparc keyboard (/dev/kbd) - -- DSP56001 digital signal processor (/dev/dsp56k) - -- Apple Desktop Bus (/dev/adb) - -- Coda network file system (/dev/cfs*) - -- Virtual console capture devices (/dev/vcc) - Thanks to Dennis Hou - -- Frame buffer devices (/dev/fb) - -- Video capture devices (/dev/v4l) - - ------------------------------------------------------------------------------ - - -Allocation of Device Numbers - -Devfs allows you to write a driver which doesn't need to allocate a -device number (major&minor numbers) for the internal operation of the -kernel. However, there are a number of userspace programmes that use -the device number as a unique handle for a device. An example is the -find programme, which uses device numbers to determine whether -an inode is on a different filesystem than another inode. The device -number used is the one for the block device which a filesystem is -using. To preserve compatibility with userspace programmes, block -devices using devfs need to have unique device numbers allocated to -them. Furthermore, POSIX specifies device numbers, so some kind of -device number needs to be presented to userspace. - -The simplest option (especially when porting drivers to devfs) is to -keep using the old major and minor numbers. Devfs will take whatever -values are given for major&minor and pass them onto userspace. - -This device number is a 16 bit number, so this leaves plenty of space -for large numbers of discs and partitions. This scheme can also be -used for character devices, in particular the tty devices, which are -currently limited to 256 pseudo-ttys (this limits the total number of -simultaneous xterms and remote logins). Note that the device number -is limited to the range 36864-61439 (majors 144-239), in order to -avoid any possible conflicts with existing official allocations. - -Please note that using dynamically allocated block device numbers may -break the NFS daemons (both user and kernel mode), which expect dev_t -for a given device to be constant over the lifetime of remote mounts. - -A final note on this scheme: since it doesn't increase the size of -device numbers, there are no compatibility issues with userspace. - ------------------------------------------------------------------------------ - - -Questions and Answers - - -Making things work -Alternatives to devfs -What I don't like about devfs -How to report bugs -Strange kernel messages -Compilation problems with devfsd - - - -Making things work - -Here are some common questions and answers. - - - -Devfsd doesn't start - -Make sure you have compiled and installed devfsd -Make sure devfsd is being started from your boot -scripts -Make sure you have configured your kernel to enable devfs (see -below) -Make sure devfs is mounted (see below) - - -Devfsd is not managing all my permissions - -Make sure you are capturing the appropriate events. For example, -device entries created by the kernel generate REGISTER events, -but those created by devfsd generate CREATE events. - - -Devfsd is not capturing all REGISTER events - -See the previous entry: you may need to capture CREATE events. - - -X will not start - -Make sure you followed the steps -outlined above. - - -Why don't my network devices appear in devfs? - -This is not a bug. Network devices have their own, completely separate -namespace. They are accessed via socket(2) and -setsockopt(2) calls, and thus require no device nodes. I have -raised the possibilty of moving network devices into the device -namespace, but have had no response. - - -How can I test if I have devfs compiled into my kernel? - -All filesystems built-in or currently loaded are listed in -/proc/filesystems. If you see a devfs entry, then -you know that devfs was compiled into your kernel. If you have -correctly configured and rebuilt your kernel, then devfs will be -built-in. If you think you've configured it in, but -/proc/filesystems doesn't show it, you've made a mistake. -Common mistakes include: - -Using a 2.2.x kernel without applying the devfs patch (if you -don't know how to patch your kernel, use 2.4.x instead, don't bother -asking me how to patch) -Forgetting to set CONFIG_EXPERIMENTAL=y -Forgetting to set CONFIG_DEVFS_FS=y -Forgetting to set CONFIG_DEVFS_MOUNT=y (if you want devfs -to be automatically mounted at boot) -Editing your .config manually, instead of using make -config or make xconfig -Forgetting to run make dep; make clean after changing the -configuration and before compiling -Forgetting to compile your kernel and modules -Forgetting to install your kernel -Forgetting to install your modules - -Please check twice that you've done all these steps before sending in -a bug report. - - - -How can I test if devfs is mounted on /dev? - -The device filesystem will always create an entry called -".devfsd", which is used to communicate with the daemon. Even -if the daemon is not running, this entry will exist. Testing for the -existence of this entry is the approved method of determining if devfs -is mounted or not. Note that the type of entry (i.e. regular file, -character device, named pipe, etc.) may change without notice. Only -the existence of the entry should be relied upon. - - -When I start devfsd, I see the error: -Error opening file: ".devfsd" No such file or directory? - -This means that devfs is not mounted. Make sure you have devfs mounted. - - -How do I mount devfs? - -First make sure you have devfs compiled into your kernel (see -above). Then you will either need to: - -set CONFIG_DEVFS_MOUNT=y in your kernel config -pass devfs=mount to your boot loader -mount devfs manually in your boot scripts with: -mount -t none devfs /dev - - - -Mount by volume LABEL=