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authorIngo Molnar <mingo@elte.hu>2008-10-28 16:26:12 +0100
committerIngo Molnar <mingo@elte.hu>2008-10-28 16:26:12 +0100
commit7a9787e1eba95a166265e6a260cf30af04ef0a99 (patch)
treee730a4565e0318140d2fbd2f0415d18a339d7336 /Documentation/filesystems
parent41b9eb264c8407655db57b60b4457fe1b2ec9977 (diff)
parent0173a3265b228da319ceb9c1ec6a5682fd1b2d92 (diff)
Merge commit 'v2.6.28-rc2' into x86/pci-ioapic-boot-irq-quirks
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/Locking22
-rw-r--r--Documentation/filesystems/autofs4-mount-control.txt393
-rw-r--r--Documentation/filesystems/bfs.txt10
-rw-r--r--Documentation/filesystems/configfs/Makefile3
-rw-r--r--Documentation/filesystems/configfs/configfs.txt27
-rw-r--r--Documentation/filesystems/configfs/configfs_example_explicit.c (renamed from Documentation/filesystems/configfs/configfs_example.c)32
-rw-r--r--Documentation/filesystems/configfs/configfs_example_macros.c448
-rw-r--r--Documentation/filesystems/ext3.txt8
-rw-r--r--Documentation/filesystems/ext4.txt57
-rw-r--r--Documentation/filesystems/fiemap.txt228
-rw-r--r--Documentation/filesystems/nfs-rdma.txt103
-rw-r--r--Documentation/filesystems/nfsroot.txt2
-rw-r--r--Documentation/filesystems/ntfs.txt4
-rw-r--r--Documentation/filesystems/ocfs2.txt6
-rw-r--r--Documentation/filesystems/omfs.txt106
-rw-r--r--Documentation/filesystems/proc.txt177
-rw-r--r--Documentation/filesystems/quota.txt22
-rw-r--r--Documentation/filesystems/ramfs-rootfs-initramfs.txt2
-rw-r--r--Documentation/filesystems/relay.txt10
-rw-r--r--Documentation/filesystems/sysfs.txt6
-rw-r--r--Documentation/filesystems/ubifs.txt11
-rw-r--r--Documentation/filesystems/vfat.txt8
-rw-r--r--Documentation/filesystems/vfs.txt6
23 files changed, 1516 insertions, 175 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 8b22d7d8b99..8362860e21a 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -144,8 +144,8 @@ prototypes:
void (*kill_sb) (struct super_block *);
locking rules:
may block BKL
-get_sb yes yes
-kill_sb yes yes
+get_sb yes no
+kill_sb yes no
->get_sb() returns error or 0 with locked superblock attached to the vfsmount
(exclusive on ->s_umount).
@@ -409,12 +409,12 @@ ioctl: yes (see below)
unlocked_ioctl: no (see below)
compat_ioctl: no
mmap: no
-open: maybe (see below)
+open: no
flush: no
release: no
fsync: no (see below)
aio_fsync: no
-fasync: yes (see below)
+fasync: no
lock: yes
readv: no
writev: no
@@ -431,13 +431,6 @@ For many filesystems, it is probably safe to acquire the inode
semaphore. Note some filesystems (i.e. remote ones) provide no
protection for i_size so you will need to use the BKL.
-->open() locking is in-transit: big lock partially moved into the methods.
-The only exception is ->open() in the instances of file_operations that never
-end up in ->i_fop/->proc_fops, i.e. ones that belong to character devices
-(chrdev_open() takes lock before replacing ->f_op and calling the secondary
-method. As soon as we fix the handling of module reference counters all
-instances of ->open() will be called without the BKL.
-
Note: ext2_release() was *the* source of contention on fs-intensive
loads and dropping BKL on ->release() helps to get rid of that (we still
grab BKL for cases when we close a file that had been opened r/w, but that
@@ -510,6 +503,7 @@ prototypes:
void (*close)(struct vm_area_struct*);
int (*fault)(struct vm_area_struct*, struct vm_fault *);
int (*page_mkwrite)(struct vm_area_struct *, struct page *);
+ int (*access)(struct vm_area_struct *, unsigned long, void*, int, int);
locking rules:
BKL mmap_sem PageLocked(page)
@@ -517,6 +511,7 @@ open: no yes
close: no yes
fault: no yes
page_mkwrite: no yes no
+access: no yes
->page_mkwrite() is called when a previously read-only page is
about to become writeable. The file system is responsible for
@@ -525,6 +520,11 @@ taking to lock out truncate, the page range should be verified to be
within i_size. The page mapping should also be checked that it is not
NULL.
+ ->access() is called when get_user_pages() fails in
+acces_process_vm(), typically used to debug a process through
+/proc/pid/mem or ptrace. This function is needed only for
+VM_IO | VM_PFNMAP VMAs.
+
================================================================================
Dubious stuff
diff --git a/Documentation/filesystems/autofs4-mount-control.txt b/Documentation/filesystems/autofs4-mount-control.txt
new file mode 100644
index 00000000000..c6341745df3
--- /dev/null
+++ b/Documentation/filesystems/autofs4-mount-control.txt
@@ -0,0 +1,393 @@
+
+Miscellaneous Device control operations for the autofs4 kernel module
+====================================================================
+
+The problem
+===========
+
+There is a problem with active restarts in autofs (that is to say
+restarting autofs when there are busy mounts).
+
+During normal operation autofs uses a file descriptor opened on the
+directory that is being managed in order to be able to issue control
+operations. Using a file descriptor gives ioctl operations access to
+autofs specific information stored in the super block. The operations
+are things such as setting an autofs mount catatonic, setting the
+expire timeout and requesting expire checks. As is explained below,
+certain types of autofs triggered mounts can end up covering an autofs
+mount itself which prevents us being able to use open(2) to obtain a
+file descriptor for these operations if we don't already have one open.
+
+Currently autofs uses "umount -l" (lazy umount) to clear active mounts
+at restart. While using lazy umount works for most cases, anything that
+needs to walk back up the mount tree to construct a path, such as
+getcwd(2) and the proc file system /proc/<pid>/cwd, no longer works
+because the point from which the path is constructed has been detached
+from the mount tree.
+
+The actual problem with autofs is that it can't reconnect to existing
+mounts. Immediately one thinks of just adding the ability to remount
+autofs file systems would solve it, but alas, that can't work. This is
+because autofs direct mounts and the implementation of "on demand mount
+and expire" of nested mount trees have the file system mounted directly
+on top of the mount trigger directory dentry.
+
+For example, there are two types of automount maps, direct (in the kernel
+module source you will see a third type called an offset, which is just
+a direct mount in disguise) and indirect.
+
+Here is a master map with direct and indirect map entries:
+
+/- /etc/auto.direct
+/test /etc/auto.indirect
+
+and the corresponding map files:
+
+/etc/auto.direct:
+
+/automount/dparse/g6 budgie:/autofs/export1
+/automount/dparse/g1 shark:/autofs/export1
+and so on.
+
+/etc/auto.indirect:
+
+g1 shark:/autofs/export1
+g6 budgie:/autofs/export1
+and so on.
+
+For the above indirect map an autofs file system is mounted on /test and
+mounts are triggered for each sub-directory key by the inode lookup
+operation. So we see a mount of shark:/autofs/export1 on /test/g1, for
+example.
+
+The way that direct mounts are handled is by making an autofs mount on
+each full path, such as /automount/dparse/g1, and using it as a mount
+trigger. So when we walk on the path we mount shark:/autofs/export1 "on
+top of this mount point". Since these are always directories we can
+use the follow_link inode operation to trigger the mount.
+
+But, each entry in direct and indirect maps can have offsets (making
+them multi-mount map entries).
+
+For example, an indirect mount map entry could also be:
+
+g1 \
+ / shark:/autofs/export5/testing/test \
+ /s1 shark:/autofs/export/testing/test/s1 \
+ /s2 shark:/autofs/export5/testing/test/s2 \
+ /s1/ss1 shark:/autofs/export1 \
+ /s2/ss2 shark:/autofs/export2
+
+and a similarly a direct mount map entry could also be:
+
+/automount/dparse/g1 \
+ / shark:/autofs/export5/testing/test \
+ /s1 shark:/autofs/export/testing/test/s1 \
+ /s2 shark:/autofs/export5/testing/test/s2 \
+ /s1/ss1 shark:/autofs/export2 \
+ /s2/ss2 shark:/autofs/export2
+
+One of the issues with version 4 of autofs was that, when mounting an
+entry with a large number of offsets, possibly with nesting, we needed
+to mount and umount all of the offsets as a single unit. Not really a
+problem, except for people with a large number of offsets in map entries.
+This mechanism is used for the well known "hosts" map and we have seen
+cases (in 2.4) where the available number of mounts are exhausted or
+where the number of privileged ports available is exhausted.
+
+In version 5 we mount only as we go down the tree of offsets and
+similarly for expiring them which resolves the above problem. There is
+somewhat more detail to the implementation but it isn't needed for the
+sake of the problem explanation. The one important detail is that these
+offsets are implemented using the same mechanism as the direct mounts
+above and so the mount points can be covered by a mount.
+
+The current autofs implementation uses an ioctl file descriptor opened
+on the mount point for control operations. The references held by the
+descriptor are accounted for in checks made to determine if a mount is
+in use and is also used to access autofs file system information held
+in the mount super block. So the use of a file handle needs to be
+retained.
+
+
+The Solution
+============
+
+To be able to restart autofs leaving existing direct, indirect and
+offset mounts in place we need to be able to obtain a file handle
+for these potentially covered autofs mount points. Rather than just
+implement an isolated operation it was decided to re-implement the
+existing ioctl interface and add new operations to provide this
+functionality.
+
+In addition, to be able to reconstruct a mount tree that has busy mounts,
+the uid and gid of the last user that triggered the mount needs to be
+available because these can be used as macro substitution variables in
+autofs maps. They are recorded at mount request time and an operation
+has been added to retrieve them.
+
+Since we're re-implementing the control interface, a couple of other
+problems with the existing interface have been addressed. First, when
+a mount or expire operation completes a status is returned to the
+kernel by either a "send ready" or a "send fail" operation. The
+"send fail" operation of the ioctl interface could only ever send
+ENOENT so the re-implementation allows user space to send an actual
+status. Another expensive operation in user space, for those using
+very large maps, is discovering if a mount is present. Usually this
+involves scanning /proc/mounts and since it needs to be done quite
+often it can introduce significant overhead when there are many entries
+in the mount table. An operation to lookup the mount status of a mount
+point dentry (covered or not) has also been added.
+
+Current kernel development policy recommends avoiding the use of the
+ioctl mechanism in favor of systems such as Netlink. An implementation
+using this system was attempted to evaluate its suitability and it was
+found to be inadequate, in this case. The Generic Netlink system was
+used for this as raw Netlink would lead to a significant increase in
+complexity. There's no question that the Generic Netlink system is an
+elegant solution for common case ioctl functions but it's not a complete
+replacement probably because it's primary purpose in life is to be a
+message bus implementation rather than specifically an ioctl replacement.
+While it would be possible to work around this there is one concern
+that lead to the decision to not use it. This is that the autofs
+expire in the daemon has become far to complex because umount
+candidates are enumerated, almost for no other reason than to "count"
+the number of times to call the expire ioctl. This involves scanning
+the mount table which has proved to be a big overhead for users with
+large maps. The best way to improve this is try and get back to the
+way the expire was done long ago. That is, when an expire request is
+issued for a mount (file handle) we should continually call back to
+the daemon until we can't umount any more mounts, then return the
+appropriate status to the daemon. At the moment we just expire one
+mount at a time. A Generic Netlink implementation would exclude this
+possibility for future development due to the requirements of the
+message bus architecture.
+
+
+autofs4 Miscellaneous Device mount control interface
+====================================================
+
+The control interface is opening a device node, typically /dev/autofs.
+
+All the ioctls use a common structure to pass the needed parameter
+information and return operation results:
+
+struct autofs_dev_ioctl {
+ __u32 ver_major;
+ __u32 ver_minor;
+ __u32 size; /* total size of data passed in
+ * including this struct */
+ __s32 ioctlfd; /* automount command fd */
+
+ __u32 arg1; /* Command parameters */
+ __u32 arg2;
+
+ char path[0];
+};
+
+The ioctlfd field is a mount point file descriptor of an autofs mount
+point. It is returned by the open call and is used by all calls except
+the check for whether a given path is a mount point, where it may
+optionally be used to check a specific mount corresponding to a given
+mount point file descriptor, and when requesting the uid and gid of the
+last successful mount on a directory within the autofs file system.
+
+The fields arg1 and arg2 are used to communicate parameters and results of
+calls made as described below.
+
+The path field is used to pass a path where it is needed and the size field
+is used account for the increased structure length when translating the
+structure sent from user space.
+
+This structure can be initialized before setting specific fields by using
+the void function call init_autofs_dev_ioctl(struct autofs_dev_ioctl *).
+
+All of the ioctls perform a copy of this structure from user space to
+kernel space and return -EINVAL if the size parameter is smaller than
+the structure size itself, -ENOMEM if the kernel memory allocation fails
+or -EFAULT if the copy itself fails. Other checks include a version check
+of the compiled in user space version against the module version and a
+mismatch results in a -EINVAL return. If the size field is greater than
+the structure size then a path is assumed to be present and is checked to
+ensure it begins with a "/" and is NULL terminated, otherwise -EINVAL is
+returned. Following these checks, for all ioctl commands except
+AUTOFS_DEV_IOCTL_VERSION_CMD, AUTOFS_DEV_IOCTL_OPENMOUNT_CMD and
+AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD the ioctlfd is validated and if it is
+not a valid descriptor or doesn't correspond to an autofs mount point
+an error of -EBADF, -ENOTTY or -EINVAL (not an autofs descriptor) is
+returned.
+
+
+The ioctls
+==========
+
+An example of an implementation which uses this interface can be seen
+in autofs version 5.0.4 and later in file lib/dev-ioctl-lib.c of the
+distribution tar available for download from kernel.org in directory
+/pub/linux/daemons/autofs/v5.
+
+The device node ioctl operations implemented by this interface are:
+
+
+AUTOFS_DEV_IOCTL_VERSION
+------------------------
+
+Get the major and minor version of the autofs4 device ioctl kernel module
+implementation. It requires an initialized struct autofs_dev_ioctl as an
+input parameter and sets the version information in the passed in structure.
+It returns 0 on success or the error -EINVAL if a version mismatch is
+detected.
+
+
+AUTOFS_DEV_IOCTL_PROTOVER_CMD and AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD
+------------------------------------------------------------------
+
+Get the major and minor version of the autofs4 protocol version understood
+by loaded module. This call requires an initialized struct autofs_dev_ioctl
+with the ioctlfd field set to a valid autofs mount point descriptor
+and sets the requested version number in structure field arg1. These
+commands return 0 on success or one of the negative error codes if
+validation fails.
+
+
+AUTOFS_DEV_IOCTL_OPENMOUNT and AUTOFS_DEV_IOCTL_CLOSEMOUNT
+----------------------------------------------------------
+
+Obtain and release a file descriptor for an autofs managed mount point
+path. The open call requires an initialized struct autofs_dev_ioctl with
+the the path field set and the size field adjusted appropriately as well
+as the arg1 field set to the device number of the autofs mount. The
+device number can be obtained from the mount options shown in
+/proc/mounts. The close call requires an initialized struct
+autofs_dev_ioct with the ioctlfd field set to the descriptor obtained
+from the open call. The release of the file descriptor can also be done
+with close(2) so any open descriptors will also be closed at process exit.
+The close call is included in the implemented operations largely for
+completeness and to provide for a consistent user space implementation.
+
+
+AUTOFS_DEV_IOCTL_READY_CMD and AUTOFS_DEV_IOCTL_FAIL_CMD
+--------------------------------------------------------
+
+Return mount and expire result status from user space to the kernel.
+Both of these calls require an initialized struct autofs_dev_ioctl
+with the ioctlfd field set to the descriptor obtained from the open
+call and the arg1 field set to the wait queue token number, received
+by user space in the foregoing mount or expire request. The arg2 field
+is set to the status to be returned. For the ready call this is always
+0 and for the fail call it is set to the errno of the operation.
+
+
+AUTOFS_DEV_IOCTL_SETPIPEFD_CMD
+------------------------------
+
+Set the pipe file descriptor used for kernel communication to the daemon.
+Normally this is set at mount time using an option but when reconnecting
+to a existing mount we need to use this to tell the autofs mount about
+the new kernel pipe descriptor. In order to protect mounts against
+incorrectly setting the pipe descriptor we also require that the autofs
+mount be catatonic (see next call).
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call and
+the arg1 field set to descriptor of the pipe. On success the call
+also sets the process group id used to identify the controlling process
+(eg. the owning automount(8) daemon) to the process group of the caller.
+
+
+AUTOFS_DEV_IOCTL_CATATONIC_CMD
+------------------------------
+
+Make the autofs mount point catatonic. The autofs mount will no longer
+issue mount requests, the kernel communication pipe descriptor is released
+and any remaining waits in the queue released.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call.
+
+
+AUTOFS_DEV_IOCTL_TIMEOUT_CMD
+----------------------------
+
+Set the expire timeout for mounts withing an autofs mount point.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call.
+
+
+AUTOFS_DEV_IOCTL_REQUESTER_CMD
+------------------------------
+
+Return the uid and gid of the last process to successfully trigger a the
+mount on the given path dentry.
+
+The call requires an initialized struct autofs_dev_ioctl with the path
+field set to the mount point in question and the size field adjusted
+appropriately as well as the arg1 field set to the device number of the
+containing autofs mount. Upon return the struct field arg1 contains the
+uid and arg2 the gid.
+
+When reconstructing an autofs mount tree with active mounts we need to
+re-connect to mounts that may have used the original process uid and
+gid (or string variations of them) for mount lookups within the map entry.
+This call provides the ability to obtain this uid and gid so they may be
+used by user space for the mount map lookups.
+
+
+AUTOFS_DEV_IOCTL_EXPIRE_CMD
+---------------------------
+
+Issue an expire request to the kernel for an autofs mount. Typically
+this ioctl is called until no further expire candidates are found.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call. In
+addition an immediate expire, independent of the mount timeout, can be
+requested by setting the arg1 field to 1. If no expire candidates can
+be found the ioctl returns -1 with errno set to EAGAIN.
+
+This call causes the kernel module to check the mount corresponding
+to the given ioctlfd for mounts that can be expired, issues an expire
+request back to the daemon and waits for completion.
+
+AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD
+------------------------------
+
+Checks if an autofs mount point is in use.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call and
+it returns the result in the arg1 field, 1 for busy and 0 otherwise.
+
+
+AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
+---------------------------------
+
+Check if the given path is a mountpoint.
+
+The call requires an initialized struct autofs_dev_ioctl. There are two
+possible variations. Both use the path field set to the path of the mount
+point to check and the size field adjusted appropriately. One uses the
+ioctlfd field to identify a specific mount point to check while the other
+variation uses the path and optionaly arg1 set to an autofs mount type.
+The call returns 1 if this is a mount point and sets arg1 to the device
+number of the mount and field arg2 to the relevant super block magic
+number (described below) or 0 if it isn't a mountpoint. In both cases
+the the device number (as returned by new_encode_dev()) is returned
+in field arg1.
+
+If supplied with a file descriptor we're looking for a specific mount,
+not necessarily at the top of the mounted stack. In this case the path
+the descriptor corresponds to is considered a mountpoint if it is itself
+a mountpoint or contains a mount, such as a multi-mount without a root
+mount. In this case we return 1 if the descriptor corresponds to a mount
+point and and also returns the super magic of the covering mount if there
+is one or 0 if it isn't a mountpoint.
+
+If a path is supplied (and the ioctlfd field is set to -1) then the path
+is looked up and is checked to see if it is the root of a mount. If a
+type is also given we are looking for a particular autofs mount and if
+a match isn't found a fail is returned. If the the located path is the
+root of a mount 1 is returned along with the super magic of the mount
+or 0 otherwise.
+
diff --git a/Documentation/filesystems/bfs.txt b/Documentation/filesystems/bfs.txt
index ea825e178e7..78043d5a8fc 100644
--- a/Documentation/filesystems/bfs.txt
+++ b/Documentation/filesystems/bfs.txt
@@ -26,11 +26,11 @@ You can simplify mounting by just typing:
this will allocate the first available loopback device (and load loop.o
kernel module if necessary) automatically. If the loopback driver is not
-loaded automatically, make sure that your kernel is compiled with kmod
-support (CONFIG_KMOD) enabled. Beware that umount will not
-deallocate /dev/loopN device if /etc/mtab file on your system is a
-symbolic link to /proc/mounts. You will need to do it manually using
-"-d" switch of losetup(8). Read losetup(8) manpage for more info.
+loaded automatically, make sure that you have compiled the module and
+that modprobe is functioning. Beware that umount will not deallocate
+/dev/loopN device if /etc/mtab file on your system is a symbolic link to
+/proc/mounts. You will need to do it manually using "-d" switch of
+losetup(8). Read losetup(8) manpage for more info.
To create the BFS image under UnixWare you need to find out first which
slice contains it. The command prtvtoc(1M) is your friend:
diff --git a/Documentation/filesystems/configfs/Makefile b/Documentation/filesystems/configfs/Makefile
new file mode 100644
index 00000000000..be7ec5e67db
--- /dev/null
+++ b/Documentation/filesystems/configfs/Makefile
@@ -0,0 +1,3 @@
+ifneq ($(CONFIG_CONFIGFS_FS),)
+obj-m += configfs_example_explicit.o configfs_example_macros.o
+endif
diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs/configfs.txt
index 15838d706ea..fabcb0e00f2 100644
--- a/Documentation/filesystems/configfs/configfs.txt
+++ b/Documentation/filesystems/configfs/configfs.txt
@@ -233,12 +233,10 @@ accomplished via the group operations specified on the group's
config_item_type.
struct configfs_group_operations {
- int (*make_item)(struct config_group *group,
- const char *name,
- struct config_item **new_item);
- int (*make_group)(struct config_group *group,
- const char *name,
- struct config_group **new_group);
+ struct config_item *(*make_item)(struct config_group *group,
+ const char *name);
+ struct config_group *(*make_group)(struct config_group *group,
+ const char *name);
int (*commit_item)(struct config_item *item);
void (*disconnect_notify)(struct config_group *group,
struct config_item *item);
@@ -313,9 +311,20 @@ the subsystem must be ready for it.
[An Example]
The best example of these basic concepts is the simple_children
-subsystem/group and the simple_child item in configfs_example.c It
-shows a trivial object displaying and storing an attribute, and a simple
-group creating and destroying these children.
+subsystem/group and the simple_child item in configfs_example_explicit.c
+and configfs_example_macros.c. It shows a trivial object displaying and
+storing an attribute, and a simple group creating and destroying these
+children.
+
+The only difference between configfs_example_explicit.c and
+configfs_example_macros.c is how the attributes of the childless item
+are defined. The childless item has extended attributes, each with
+their own show()/store() operation. This follows a convention commonly
+used in sysfs. configfs_example_explicit.c creates these attributes
+by explicitly defining the structures involved. Conversely
+configfs_example_macros.c uses some convenience macros from configfs.h
+to define the attributes. These macros are similar to their sysfs
+counterparts.
[Hierarchy Navigation and the Subsystem Mutex]
diff --git a/Documentation/filesystems/configfs/configfs_example.c b/Documentation/filesystems/configfs/configfs_example_explicit.c
index 0b422acd470..d428cc9f07f 100644
--- a/Documentation/filesystems/configfs/configfs_example.c
+++ b/Documentation/filesystems/configfs/configfs_example_explicit.c
@@ -1,8 +1,10 @@
/*
* vim: noexpandtab ts=8 sts=0 sw=8:
*
- * configfs_example.c - This file is a demonstration module containing
- * a number of configfs subsystems.
+ * configfs_example_explicit.c - This file is a demonstration module
+ * containing a number of configfs subsystems. It explicitly defines
+ * each structure without using the helper macros defined in
+ * configfs.h.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
@@ -273,22 +275,20 @@ static inline struct simple_children *to_simple_children(struct config_item *ite
return item ? container_of(to_config_group(item), struct simple_children, group) : NULL;
}
-static int simple_children_make_item(struct config_group *group, const char *name, struct config_item **new_item)
+static struct config_item *simple_children_make_item(struct config_group *group, const char *name)
{
struct simple_child *simple_child;
simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
if (!simple_child)
- return -ENOMEM;
-
+ return ERR_PTR(-ENOMEM);
config_item_init_type_name(&simple_child->item, name,
&simple_child_type);
simple_child->storeme = 0;
- *new_item = &simple_child->item;
- return 0;
+ return &simple_child->item;
}
static struct configfs_attribute simple_children_attr_description = {
@@ -303,8 +303,8 @@ static struct configfs_attribute *simple_children_attrs[] = {
};
static ssize_t simple_children_attr_show(struct config_item *item,
- struct configfs_attribute *attr,
- char *page)
+ struct configfs_attribute *attr,
+ char *page)
{
return sprintf(page,
"[02-simple-children]\n"
@@ -319,7 +319,7 @@ static void simple_children_release(struct config_item *item)
}
static struct configfs_item_operations simple_children_item_ops = {
- .release = simple_children_release,
+ .release = simple_children_release,
.show_attribute = simple_children_attr_show,
};
@@ -360,21 +360,19 @@ static struct configfs_subsystem simple_children_subsys = {
* children of its own.
*/
-static int group_children_make_group(struct config_group *group, const char *name, struct config_group **new_group)
+static struct config_group *group_children_make_group(struct config_group *group, const char *name)
{
struct simple_children *simple_children;
simple_children = kzalloc(sizeof(struct simple_children),
GFP_KERNEL);
if (!simple_children)
- return -ENOMEM;
-
+ return ERR_PTR(-ENOMEM);
config_group_init_type_name(&simple_children->group, name,
&simple_children_type);
- *new_group = &simple_children->group;
- return 0;
+ return &simple_children->group;
}
static struct configfs_attribute group_children_attr_description = {
@@ -389,8 +387,8 @@ static struct configfs_attribute *group_children_attrs[] = {
};
static ssize_t group_children_attr_show(struct config_item *item,
- struct configfs_attribute *attr,
- char *page)
+ struct configfs_attribute *attr,
+ char *page)
{
return sprintf(page,
"[03-group-children]\n"
diff --git a/Documentation/filesystems/configfs/configfs_example_macros.c b/Documentation/filesystems/configfs/configfs_example_macros.c
new file mode 100644
index 00000000000..d8e30a0378a
--- /dev/null
+++ b/Documentation/filesystems/configfs/configfs_example_macros.c
@@ -0,0 +1,448 @@
+/*
+ * vim: noexpandtab ts=8 sts=0 sw=8:
+ *
+ * configfs_example_macros.c - This file is a demonstration module
+ * containing a number of configfs subsystems. It uses the helper
+ * macros defined by configfs.h
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/configfs.h>
+
+
+
+/*
+ * 01-childless
+ *
+ * This first example is a childless subsystem. It cannot create
+ * any config_items. It just has attributes.
+ *
+ * Note that we are enclosing the configfs_subsystem inside a container.
+ * This is not necessary if a subsystem has no attributes directly
+ * on the subsystem. See the next example, 02-simple-children, for
+ * such a subsystem.
+ */
+
+struct childless {
+ struct configfs_subsystem subsys;
+ int showme;
+ int storeme;
+};
+
+static inline struct childless *to_childless(struct config_item *item)
+{
+ return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct childless, subsys) : NULL;
+}
+
+CONFIGFS_ATTR_STRUCT(childless);
+#define CHILDLESS_ATTR(_name, _mode, _show, _store) \
+struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR(_name, _mode, _show, _store)
+#define CHILDLESS_ATTR_RO(_name, _show) \
+struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR_RO(_name, _show);
+
+static ssize_t childless_showme_read(struct childless *childless,
+ char *page)
+{
+ ssize_t pos;
+
+ pos = sprintf(page, "%d\n", childless->showme);
+ childless->showme++;
+
+ return pos;
+}
+
+static ssize_t childless_storeme_read(struct childless *childless,
+ char *page)
+{
+ return sprintf(page, "%d\n", childless->storeme);
+}
+
+static ssize_t childless_storeme_write(struct childless *childless,
+ const char *page,
+ size_t count)
+{
+ unsigned long tmp;
+ char *p = (char *) page;
+
+ tmp = simple_strtoul(p, &p, 10);
+ if (!p || (*p && (*p != '\n')))
+ return -EINVAL;
+
+ if (tmp > INT_MAX)
+ return -ERANGE;
+
+ childless->storeme = tmp;
+
+ return count;
+}
+
+static ssize_t childless_description_read(struct childless *childless,
+ char *page)
+{
+ return sprintf(page,
+"[01-childless]\n"
+"\n"
+"The childless subsystem is the simplest possible subsystem in\n"
+"configfs. It does not support the creation of child config_items.\n"
+"It only has a few attributes. In fact, it isn't much different\n"
+"than a directory in /proc.\n");
+}
+
+CHILDLESS_ATTR_RO(showme, childless_showme_read);
+CHILDLESS_ATTR(storeme, S_IRUGO | S_IWUSR, childless_storeme_read,
+ childless_storeme_write);
+CHILDLESS_ATTR_RO(description, childless_description_read);
+
+static struct configfs_attribute *childless_attrs[] = {
+ &childless_attr_showme.attr,
+ &childless_attr_storeme.attr,
+ &childless_attr_description.attr,
+ NULL,
+};
+
+CONFIGFS_ATTR_OPS(childless);
+static struct configfs_item_operations childless_item_ops = {
+ .show_attribute = childless_attr_show,
+ .store_attribute = childless_attr_store,
+};
+
+static struct config_item_type childless_type = {
+ .ct_item_ops = &childless_item_ops,
+ .ct_attrs = childless_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct childless childless_subsys = {
+ .subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "01-childless",
+ .ci_type = &childless_type,
+ },
+ },
+ },
+};
+
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * 02-simple-children
+ *
+ * This example merely has a simple one-attribute child. Note that
+ * there is no extra attribute structure, as the child's attribute is
+ * known from the get-go. Also, there is no container for the
+ * subsystem, as it has no attributes of its own.
+ */
+
+struct simple_child {
+ struct config_item item;
+ int storeme;
+};
+
+static inline struct simple_child *to_simple_child(struct config_item *item)
+{
+ return item ? container_of(item, struct simple_child, item) : NULL;
+}
+
+static struct configfs_attribute simple_child_attr_storeme = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "storeme",
+ .ca_mode = S_IRUGO | S_IWUSR,
+};
+
+static struct configfs_attribute *simple_child_attrs[] = {
+ &simple_child_attr_storeme,
+ NULL,
+};
+
+static ssize_t simple_child_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ ssize_t count;
+ struct simple_child *simple_child = to_simple_child(item);
+
+ count = sprintf(page, "%d\n", simple_child->storeme);
+
+ return count;
+}
+
+static ssize_t simple_child_attr_store(struct config_item *item,
+ struct configfs_attribute *attr,
+ const char *page, size_t count)
+{
+ struct simple_child *simple_child = to_simple_child(item);
+ unsigned long tmp;
+ char *p = (char *) page;
+
+ tmp = simple_strtoul(p, &p, 10);
+ if (!p || (*p && (*p != '\n')))
+ return -EINVAL;
+
+ if (tmp > INT_MAX)
+ return -ERANGE;
+
+ simple_child->storeme = tmp;
+
+ return count;
+}
+
+static void simple_child_release(struct config_item *item)
+{
+ kfree(to_simple_child(item));
+}
+
+static struct configfs_item_operations simple_child_item_ops = {
+ .release = simple_child_release,
+ .show_attribute = simple_child_attr_show,
+ .store_attribute = simple_child_attr_store,
+};
+
+static struct config_item_type simple_child_type = {
+ .ct_item_ops = &simple_child_item_ops,
+ .ct_attrs = simple_child_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+
+struct simple_children {
+ struct config_group group;
+};
+
+static inline struct simple_children *to_simple_children(struct config_item *item)
+{
+ return item ? container_of(to_config_group(item), struct simple_children, group) : NULL;
+}
+
+static struct config_item *simple_children_make_item(struct config_group *group, const char *name)
+{
+ struct simple_child *simple_child;
+
+ simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
+ if (!simple_child)
+ return ERR_PTR(-ENOMEM);
+
+ config_item_init_type_name(&simple_child->item, name,
+ &simple_child_type);
+
+ simple_child->storeme = 0;
+
+ return &simple_child->item;
+}
+
+static struct configfs_attribute simple_children_attr_description = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "description",
+ .ca_mode = S_IRUGO,
+};
+
+static struct configfs_attribute *simple_children_attrs[] = {
+ &simple_children_attr_description,
+ NULL,
+};
+
+static ssize_t simple_children_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ return sprintf(page,
+"[02-simple-children]\n"
+"\n"
+"This subsystem allows the creation of child config_items. These\n"
+"items have only one attribute that is readable and writeable.\n");
+}
+
+static void simple_children_release(struct config_item *item)
+{
+ kfree(to_simple_children(item));
+}
+
+static struct configfs_item_operations simple_children_item_ops = {
+ .release = simple_children_release,
+ .show_attribute = simple_children_attr_show,
+};
+
+/*
+ * Note that, since no extra work is required on ->drop_item(),
+ * no ->drop_item() is provided.
+ */
+static struct configfs_group_operations simple_children_group_ops = {
+ .make_item = simple_children_make_item,
+};
+
+static struct config_item_type simple_children_type = {
+ .ct_item_ops = &simple_children_item_ops,
+ .ct_group_ops = &simple_children_group_ops,
+ .ct_attrs = simple_children_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem simple_children_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "02-simple-children",
+ .ci_type = &simple_children_type,
+ },
+ },
+};
+
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * 03-group-children
+ *
+ * This example reuses the simple_children group from above. However,
+ * the simple_children group is not the subsystem itself, it is a
+ * child of the subsystem. Creation of a group in the subsystem creates
+ * a new simple_children group. That group can then have simple_child
+ * children of its own.
+ */
+
+static struct config_group *group_children_make_group(struct config_group *group, const char *name)
+{
+ struct simple_children *simple_children;
+
+ simple_children = kzalloc(sizeof(struct simple_children),
+ GFP_KERNEL);
+ if (!simple_children)
+ return ERR_PTR(-ENOMEM);
+
+ config_group_init_type_name(&simple_children->group, name,
+ &simple_children_type);
+
+ return &simple_children->group;
+}
+
+static struct configfs_attribute group_children_attr_description = {
+ .ca_owner = THIS_MODULE,
+ .ca_name = "description",
+ .ca_mode = S_IRUGO,
+};
+
+static struct configfs_attribute *group_children_attrs[] = {
+ &group_children_attr_description,
+ NULL,
+};
+
+static ssize_t group_children_attr_show(struct config_item *item,
+ struct configfs_attribute *attr,
+ char *page)
+{
+ return sprintf(page,
+"[03-group-children]\n"
+"\n"
+"This subsystem allows the creation of child config_groups. These\n"
+"groups are like the subsystem simple-children.\n");
+}
+
+static struct configfs_item_operations group_children_item_ops = {
+ .show_attribute = group_children_attr_show,
+};
+
+/*
+ * Note that, since no extra work is required on ->drop_item(),
+ * no ->drop_item() is provided.
+ */
+static struct configfs_group_operations group_children_group_ops = {
+ .make_group = group_children_make_group,
+};
+
+static struct config_item_type group_children_type = {
+ .ct_item_ops = &group_children_item_ops,
+ .ct_group_ops = &group_children_group_ops,
+ .ct_attrs = group_children_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct configfs_subsystem group_children_subsys = {
+ .su_group = {
+ .cg_item = {
+ .ci_namebuf = "03-group-children",
+ .ci_type = &group_children_type,
+ },
+ },
+};
+
+/* ----------------------------------------------------------------- */
+
+/*
+ * We're now done with our subsystem definitions.
+ * For convenience in this module, here's a list of them all. It
+ * allows the init function to easily register them. Most modules
+ * will only have one subsystem, and will only call register_subsystem
+ * on it directly.
+ */
+static struct configfs_subsystem *example_subsys[] = {
+ &childless_subsys.subsys,
+ &simple_children_subsys,
+ &group_children_subsys,
+ NULL,
+};
+
+static int __init configfs_example_init(void)
+{
+ int ret;
+ int i;
+ struct configfs_subsystem *subsys;
+
+ for (i = 0; example_subsys[i]; i++) {
+ subsys = example_subsys[i];
+
+ config_group_init(&subsys->su_group);
+ mutex_init(&subsys->su_mutex);
+ ret = configfs_register_subsystem(subsys);
+ if (ret) {
+ printk(KERN_ERR "Error %d while registering subsystem %s\n",
+ ret,
+ subsys->su_group.cg_item.ci_namebuf);
+ goto out_unregister;
+ }
+ }
+
+ return 0;
+
+out_unregister:
+ for (; i >= 0; i--) {
+ configfs_unregister_subsystem(example_subsys[i]);
+ }
+
+ return ret;
+}
+
+static void __exit configfs_example_exit(void)
+{
+ int i;
+
+ for (i = 0; example_subsys[i]; i++) {
+ configfs_unregister_subsystem(example_subsys[i]);
+ }
+}
+
+module_init(configfs_example_init);
+module_exit(configfs_example_exit);
+MODULE_LICENSE("GPL");
diff --git a/Documentation/filesystems/ext3.txt b/Documentation/filesystems/ext3.txt
index b45f3c1b8b4..9dd2a3bb2ac 100644
--- a/Documentation/filesystems/ext3.txt
+++ b/Documentation/filesystems/ext3.txt
@@ -96,6 +96,11 @@ errors=remount-ro(*) Remount the filesystem read-only on an error.
errors=continue Keep going on a filesystem error.
errors=panic Panic and halt the machine if an error occurs.
+data_err=ignore(*) Just print an error message if an error occurs
+ in a file data buffer in ordered mode.
+data_err=abort Abort the journal if an error occurs in a file
+ data buffer in ordered mode.
+
grpid Give objects the same group ID as their creator.
bsdgroups
@@ -193,6 +198,5 @@ kernel source: <file:fs/ext3/>
programs: http://e2fsprogs.sourceforge.net/
http://ext2resize.sourceforge.net
-useful links: http://www.zip.com.au/~akpm/linux/ext3/ext3-usage.html
- http://www-106.ibm.com/developerworks/linux/library/l-fs7/
+useful links: http://www-106.ibm.com/developerworks/linux/library/l-fs7/
http://www-106.ibm.com/developerworks/linux/library/l-fs8/
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 80e193d82e2..174eaff7ded 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -2,19 +2,24 @@
Ext4 Filesystem
===============
-This is a development version of the ext4 filesystem, an advanced level
-of the ext3 filesystem which incorporates scalability and reliability
-enhancements for supporting large filesystems (64 bit) in keeping with
-increasing disk capacities and state-of-the-art feature requirements.
+Ext4 is an an advanced level of the ext3 filesystem which incorporates
+scalability and reliability enhancements for supporting large filesystems
+(64 bit) in keeping with increasing disk capacities and state-of-the-art
+feature requirements.
-Mailing list: linux-ext4@vger.kernel.org
+Mailing list: linux-ext4@vger.kernel.org
+Web site: http://ext4.wiki.kernel.org
1. Quick usage instructions:
===========================
+Note: More extensive information for getting started with ext4 can be
+ found at the ext4 wiki site at the URL:
+ http://ext4.wiki.kernel.org/index.php/Ext4_Howto
+
- Compile and install the latest version of e2fsprogs (as of this
- writing version 1.41) from:
+ writing version 1.41.3) from:
http://sourceforge.net/project/showfiles.php?group_id=2406
@@ -26,28 +31,32 @@ Mailing list: linux-ext4@vger.kernel.org
git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git
- - Create a new filesystem using the ext4dev filesystem type:
+ - Note that it is highly important to install the mke2fs.conf file
+ that comes with the e2fsprogs 1.41.x sources in /etc/mke2fs.conf. If
+ you have edited the /etc/mke2fs.conf file installed on your system,
+ you will need to merge your changes with the version from e2fsprogs
+ 1.41.x.
+
+ - Create a new filesystem using the ext4 filesystem type:
- # mke2fs -t ext4dev /dev/hda1
+ # mke2fs -t ext4 /dev/hda1
- Or configure an existing ext3 filesystem to support extents and set
- the test_fs flag to indicate that it's ok for an in-development
- filesystem to touch this filesystem:
+ Or to configure an existing ext3 filesystem to support extents:
- # tune2fs -O extents -E test_fs /dev/hda1
+ # tune2fs -O extents /dev/hda1
If the filesystem was created with 128 byte inodes, it can be
converted to use 256 byte for greater efficiency via:
# tune2fs -I 256 /dev/hda1
- (Note: we currently do not have tools to convert an ext4dev
+ (Note: we currently do not have tools to convert an ext4
filesystem back to ext3; so please do not do try this on production
filesystems.)
- Mounting:
- # mount -t ext4dev /dev/hda1 /wherever
+ # mount -t ext4 /dev/hda1 /wherever
- When comparing performance with other filesystems, remember that
ext3/4 by default offers higher data integrity guarantees than most.
@@ -98,8 +107,8 @@ exist yet so I'm not sure they're in the near-term roadmap.
The big performance win will come with mballoc, delalloc and flex_bg
grouping of bitmaps and inode tables. Some test results available here:
- - http://www.bullopensource.org/ext4/20080530/ffsb-write-2.6.26-rc2.html
- - http://www.bullopensource.org/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html
+ - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-write-2.6.27-rc1.html
+ - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-readwrite-2.6.27-rc1.html
3. Options
==========
@@ -171,6 +180,11 @@ barrier=<0|1(*)> This enables/disables the use of write barriers in
your disks are battery-backed in one way or another,
disabling barriers may safely improve performance.
+inode_readahead=n This tuning parameter controls the maximum
+ number of inode table blocks that ext4's inode
+ table readahead algorithm will pre-read into
+ the buffer cache. The default value is 32 blocks.
+
orlov (*) This enables the new Orlov block allocator. It is
enabled by default.
@@ -203,15 +217,17 @@ noreservation
bsddf (*) Make 'df' act like BSD.
minixdf Make 'df' act like Minix.
-check=none Don't do extra checking of bitmaps on mount.
-nocheck
-
debug Extra debugging information is sent to syslog.
errors=remount-ro(*) Remount the filesystem read-only on an error.
errors=continue Keep going on a filesystem error.
errors=panic Panic and halt the machine if an error occurs.
+data_err=ignore(*) Just print an error message if an error occurs
+ in a file data buffer in ordered mode.
+data_err=abort Abort the journal if an error occurs in a file
+ data buffer in ordered mode.
+
grpid Give objects the same group ID as their creator.
bsdgroups
@@ -237,8 +253,6 @@ nobh (a) cache disk block mapping information
"nobh" option tries to avoid associating buffer
heads (supported only for "writeback" mode).
-mballoc (*) Use the multiple block allocator for block allocation
-nomballoc disabled multiple block allocator for block allocation.
stripe=n Number of filesystem blocks that mballoc will try
to use for allocation size and alignment. For RAID5/6
systems this should be the number of data
@@ -246,6 +260,7 @@ stripe=n Number of filesystem blocks that mballoc will try
delalloc (*) Deferring block allocation until write-out time.
nodelalloc Disable delayed allocation. Blocks are allocation
when data is copied from user to page cache.
+
Data Mode
=========
There are 3 different data modes:
diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.txt
new file mode 100644
index 00000000000..1e3defcfe50
--- /dev/null
+++ b/Documentation/filesystems/fiemap.txt
@@ -0,0 +1,228 @@
+============
+Fiemap Ioctl
+============
+
+The fiemap ioctl is an efficient method for userspace to get file
+extent mappings. Instead of block-by-block mapping (such as bmap), fiemap
+returns a list of extents.
+
+
+Request Basics
+--------------
+
+A fiemap request is encoded within struct fiemap:
+
+struct fiemap {
+ __u64 fm_start; /* logical offset (inclusive) at
+ * which to start mapping (in) */
+ __u64 fm_length; /* logical length of mapping which
+ * userspace cares about (in) */
+ __u32 fm_flags; /* FIEMAP_FLAG_* flags for request (in/out) */
+ __u32 fm_mapped_extents; /* number of extents that were
+ * mapped (out) */
+ __u32 fm_extent_count; /* size of fm_extents array (in) */
+ __u32 fm_reserved;
+ struct fiemap_extent fm_extents[0]; /* array of mapped extents (out) */
+};
+
+
+fm_start, and fm_length specify the logical range within the file
+which the process would like mappings for. Extents returned mirror
+those on disk - that is, the logical offset of the 1st returned extent
+may start before fm_start, and the range covered by the last returned
+extent may end after fm_length. All offsets and lengths are in bytes.
+
+Certain flags to modify the way in which mappings are looked up can be
+set in fm_flags. If the kernel doesn't understand some particular
+flags, it will return EBADR and the contents of fm_flags will contain
+the set of flags which caused the error. If the kernel is compatible
+with all flags passed, the contents of fm_flags will be unmodified.
+It is up to userspace to determine whether rejection of a particular
+flag is fatal to it's operation. This scheme is intended to allow the
+fiemap interface to grow in the future but without losing
+compatibility with old software.
+
+fm_extent_count specifies the number of elements in the fm_extents[] array
+that can be used to return extents. If fm_extent_count is zero, then the
+fm_extents[] array is ignored (no extents will be returned), and the
+fm_mapped_extents count will hold the number of extents needed in
+fm_extents[] to hold the file's current mapping. Note that there is
+nothing to prevent the file from changing between calls to FIEMAP.
+
+The following flags can be set in fm_flags:
+
+* FIEMAP_FLAG_SYNC
+If this flag is set, the kernel will sync the file before mapping extents.
+
+* FIEMAP_FLAG_XATTR
+If this flag is set, the extents returned will describe the inodes
+extended attribute lookup tree, instead of it's data tree.
+
+
+Extent Mapping
+--------------
+
+Extent information is returned within the embedded fm_extents array
+which userspace must allocate along with the fiemap structure. The
+number of elements in the fiemap_extents[] array should be passed via
+fm_extent_count. The number of extents mapped by kernel will be
+returned via fm_mapped_extents. If the number of fiemap_extents
+allocated is less than would be required to map the requested range,
+the maximum number of extents that can be mapped in the fm_extent[]
+array will be returned and fm_mapped_extents will be equal to
+fm_extent_count. In that case, the last extent in the array will not
+complete the requested range and will not have the FIEMAP_EXTENT_LAST
+flag set (see the next section on extent flags).
+
+Each extent is described by a single fiemap_extent structure as
+returned in fm_extents.
+
+struct fiemap_extent {
+ __u64 fe_logical; /* logical offset in bytes for the start of
+ * the extent */
+ __u64 fe_physical; /* physical offset in bytes for the start
+ * of the extent */
+ __u64 fe_length; /* length in bytes for the extent */
+ __u64 fe_reserved64[2];
+ __u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
+ __u32 fe_reserved[3];
+};
+
+All offsets and lengths are in bytes and mirror those on disk. It is valid
+for an extents logical offset to start before the request or it's logical
+length to extend past the request. Unless FIEMAP_EXTENT_NOT_ALIGNED is
+returned, fe_logical, fe_physical, and fe_length will be aligned to the
+block size of the file system. With the exception of extents flagged as
+FIEMAP_EXTENT_MERGED, adjacent extents will not be merged.
+
+The fe_flags field contains flags which describe the extent returned.
+A special flag, FIEMAP_EXTENT_LAST is always set on the last extent in
+the file so that the process making fiemap calls can determine when no
+more extents are available, without having to call the ioctl again.
+
+Some flags are intentionally vague and will always be set in the
+presence of other more specific flags. This way a program looking for
+a general property does not have to know all existing and future flags
+which imply that property.
+
+For example, if FIEMAP_EXTENT_DATA_INLINE or FIEMAP_EXTENT_DATA_TAIL
+are set, FIEMAP_EXTENT_NOT_ALIGNED will also be set. A program looking
+for inline or tail-packed data can key on the specific flag. Software
+which simply cares not to try operating on non-aligned extents
+however, can just key on FIEMAP_EXTENT_NOT_ALIGNED, and not have to
+worry about all present and future flags which might imply unaligned
+data. Note that the opposite is not true - it would be valid for
+FIEMAP_EXTENT_NOT_ALIGNED to appear alone.
+
+* FIEMAP_EXTENT_LAST
+This is the last extent in the file. A mapping attempt past this
+extent will return nothing.
+
+* FIEMAP_EXTENT_UNKNOWN
+The location of this extent is currently unknown. This may indicate
+the data is stored on an inaccessible volume or that no storage has
+been allocated for the file yet.
+
+* FIEMAP_EXTENT_DELALLOC
+ - This will also set FIEMAP_EXTENT_UNKNOWN.
+Delayed allocation - while there is data for this extent, it's
+physical location has not been allocated yet.
+
+* FIEMAP_EXTENT_ENCODED
+This extent does not consist of plain filesystem blocks but is
+encoded (e.g. encrypted or compressed). Reading the data in this
+extent via I/O to the block device will have undefined results.
+
+Note that it is *always* undefined to try to update the data
+in-place by writing to the indicated location without the
+assistance of the filesystem, or to access the data using the
+information returned by the FIEMAP interface while the filesystem
+is mounted. In other words, user applications may only read the
+extent data via I/O to the block device while the filesystem is
+unmounted, and then only if the FIEMAP_EXTENT_ENCODED flag is
+clear; user applications must not try reading or writing to the
+filesystem via the block device under any other circumstances.
+
+* FIEMAP_EXTENT_DATA_ENCRYPTED
+ - This will also set FIEMAP_EXTENT_ENCODED
+The data in this extent has been encrypted by the file system.
+
+* FIEMAP_EXTENT_NOT_ALIGNED
+Extent offsets and length are not guaranteed to be block aligned.
+
+* FIEMAP_EXTENT_DATA_INLINE
+ This will also set FIEMAP_EXTENT_NOT_ALIGNED
+Data is located within a meta data block.
+
+* FIEMAP_EXTENT_DATA_TAIL
+ This will also set FIEMAP_EXTENT_NOT_ALIGNED
+Data is packed into a block with data from other files.
+
+* FIEMAP_EXTENT_UNWRITTEN
+Unwritten extent - the extent is allocated but it's data has not been
+initialized. This indicates the extent's data will be all zero if read
+through the filesystem but the contents are undefined if read directly from
+the device.
+
+* FIEMAP_EXTENT_MERGED
+This will be set when a file does not support extents, i.e., it uses a block
+based addressing scheme. Since returning an extent for each block back to
+userspace would be highly inefficient, the kernel will try to merge most
+adjacent blocks into 'extents'.
+
+
+VFS -> File System Implementation
+---------------------------------
+
+File systems wishing to support fiemap must implement a ->fiemap callback on
+their inode_operations structure. The fs ->fiemap call is responsible for
+defining it's set of supported fiemap flags, and calling a helper function on
+each discovered extent:
+
+struct inode_operations {
+ ...
+
+ int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
+ u64 len);
+
+->fiemap is passed struct fiemap_extent_info which describes the
+fiemap request:
+
+struct fiemap_extent_info {
+ unsigned int fi_flags; /* Flags as passed from user */
+ unsigned int fi_extents_mapped; /* Number of mapped extents */
+ unsigned int fi_extents_max; /* Size of fiemap_extent array */
+ struct fiemap_extent *fi_extents_start; /* Start of fiemap_extent array */
+};
+
+It is intended that the file system should not need to access any of this
+structure directly.
+
+
+Flag checking should be done at the beginning of the ->fiemap callback via the
+fiemap_check_flags() helper:
+
+int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
+
+The struct fieinfo should be passed in as recieved from ioctl_fiemap(). The
+set of fiemap flags which the fs understands should be passed via fs_flags. If
+fiemap_check_flags finds invalid user flags, it will place the bad values in
+fieinfo->fi_flags and return -EBADR. If the file system gets -EBADR, from
+fiemap_check_flags(), it should immediately exit, returning that error back to
+ioctl_fiemap().
+
+
+For each extent in the request range, the file system should call
+the helper function, fiemap_fill_next_extent():
+
+int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
+ u64 phys, u64 len, u32 flags, u32 dev);
+
+fiemap_fill_next_extent() will use the passed values to populate the
+next free extent in the fm_extents array. 'General' extent flags will
+automatically be set from specific flags on behalf of the calling file
+system so that the userspace API is not broken.
+
+fiemap_fill_next_extent() returns 0 on success, and 1 when the
+user-supplied fm_extents array is full. If an error is encountered
+while copying the extent to user memory, -EFAULT will be returned.
diff --git a/Documentation/filesystems/nfs-rdma.txt b/Documentation/filesystems/nfs-rdma.txt
index d0ec45ae4e7..44bd766f2e5 100644
--- a/Documentation/filesystems/nfs-rdma.txt
+++ b/Documentation/filesystems/nfs-rdma.txt
@@ -5,7 +5,7 @@
################################################################################
Author: NetApp and Open Grid Computing
- Date: April 15, 2008
+ Date: May 29, 2008
Table of Contents
~~~~~~~~~~~~~~~~~
@@ -60,16 +60,18 @@ Installation
The procedures described in this document have been tested with
distributions from Red Hat's Fedora Project (http://fedora.redhat.com/).
- - Install nfs-utils-1.1.1 or greater on the client
+ - Install nfs-utils-1.1.2 or greater on the client
- An NFS/RDMA mount point can only be obtained by using the mount.nfs
- command in nfs-utils-1.1.1 or greater. To see which version of mount.nfs
- you are using, type:
+ An NFS/RDMA mount point can be obtained by using the mount.nfs command in
+ nfs-utils-1.1.2 or greater (nfs-utils-1.1.1 was the first nfs-utils
+ version with support for NFS/RDMA mounts, but for various reasons we
+ recommend using nfs-utils-1.1.2 or greater). To see which version of
+ mount.nfs you are using, type:
- > /sbin/mount.nfs -V
+ $ /sbin/mount.nfs -V
- If the version is less than 1.1.1 or the command does not exist,
- then you will need to install the latest version of nfs-utils.
+ If the version is less than 1.1.2 or the command does not exist,
+ you should install the latest version of nfs-utils.
Download the latest package from:
@@ -77,22 +79,33 @@ Installation
Uncompress the package and follow the installation instructions.
- If you will not be using GSS and NFSv4, the installation process
- can be simplified by disabling these features when running configure:
+ If you will not need the idmapper and gssd executables (you do not need
+ these to create an NFS/RDMA enabled mount command), the installation
+ process can be simplified by disabling these features when running
+ configure:
- > ./configure --disable-gss --disable-nfsv4
+ $ ./configure --disable-gss --disable-nfsv4
- For more information on this see the package's README and INSTALL files.
+ To build nfs-utils you will need the tcp_wrappers package installed. For
+ more information on this see the package's README and INSTALL files.
After building the nfs-utils package, there will be a mount.nfs binary in
the utils/mount directory. This binary can be used to initiate NFS v2, v3,
- or v4 mounts. To initiate a v4 mount, the binary must be called mount.nfs4.
- The standard technique is to create a symlink called mount.nfs4 to mount.nfs.
+ or v4 mounts. To initiate a v4 mount, the binary must be called
+ mount.nfs4. The standard technique is to create a symlink called
+ mount.nfs4 to mount.nfs.
- NOTE: mount.nfs and therefore nfs-utils-1.1.1 or greater is only needed
+ This mount.nfs binary should be installed at /sbin/mount.nfs as follows:
+
+ $ sudo cp utils/mount/mount.nfs /sbin/mount.nfs
+
+ In this location, mount.nfs will be invoked automatically for NFS mounts
+ by the system mount commmand.
+
+ NOTE: mount.nfs and therefore nfs-utils-1.1.2 or greater is only needed
on the NFS client machine. You do not need this specific version of
nfs-utils on the server. Furthermore, only the mount.nfs command from
- nfs-utils-1.1.1 is needed on the client.
+ nfs-utils-1.1.2 is needed on the client.
- Install a Linux kernel with NFS/RDMA
@@ -156,8 +169,8 @@ Check RDMA and NFS Setup
this time. For example, if you are using a Mellanox Tavor/Sinai/Arbel
card:
- > modprobe ib_mthca
- > modprobe ib_ipoib
+ $ modprobe ib_mthca
+ $ modprobe ib_ipoib
If you are using InfiniBand, make sure there is a Subnet Manager (SM)
running on the network. If your IB switch has an embedded SM, you can
@@ -166,7 +179,7 @@ Check RDMA and NFS Setup
If an SM is running on your network, you should see the following:
- > cat /sys/class/infiniband/driverX/ports/1/state
+ $ cat /sys/class/infiniband/driverX/ports/1/state
4: ACTIVE
where driverX is mthca0, ipath5, ehca3, etc.
@@ -174,10 +187,10 @@ Check RDMA and NFS Setup
To further test the InfiniBand software stack, use IPoIB (this
assumes you have two IB hosts named host1 and host2):
- host1> ifconfig ib0 a.b.c.x
- host2> ifconfig ib0 a.b.c.y
- host1> ping a.b.c.y
- host2> ping a.b.c.x
+ host1$ ifconfig ib0 a.b.c.x
+ host2$ ifconfig ib0 a.b.c.y
+ host1$ ping a.b.c.y
+ host2$ ping a.b.c.x
For other device types, follow the appropriate procedures.
@@ -202,11 +215,11 @@ NFS/RDMA Setup
/vol0 192.168.0.47(fsid=0,rw,async,insecure,no_root_squash)
/vol0 192.168.0.0/255.255.255.0(fsid=0,rw,async,insecure,no_root_squash)
- The IP address(es) is(are) the client's IPoIB address for an InfiniBand HCA or the
- cleint's iWARP address(es) for an RNIC.
+ The IP address(es) is(are) the client's IPoIB address for an InfiniBand
+ HCA or the cleint's iWARP address(es) for an RNIC.
- NOTE: The "insecure" option must be used because the NFS/RDMA client does not
- use a reserved port.
+ NOTE: The "insecure" option must be used because the NFS/RDMA client does
+ not use a reserved port.
Each time a machine boots:
@@ -214,43 +227,45 @@ NFS/RDMA Setup
For InfiniBand using a Mellanox adapter:
- > modprobe ib_mthca
- > modprobe ib_ipoib
- > ifconfig ib0 a.b.c.d
+ $ modprobe ib_mthca
+ $ modprobe ib_ipoib
+ $ ifconfig ib0 a.b.c.d
NOTE: use unique addresses for the client and server
- Start the NFS server
- If the NFS/RDMA server was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in kernel config),
- load the RDMA transport module:
+ If the NFS/RDMA server was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in
+ kernel config), load the RDMA transport module:
- > modprobe svcrdma
+ $ modprobe svcrdma
- Regardless of how the server was built (module or built-in), start the server:
+ Regardless of how the server was built (module or built-in), start the
+ server:
- > /etc/init.d/nfs start
+ $ /etc/init.d/nfs start
or
- > service nfs start
+ $ service nfs start
Instruct the server to listen on the RDMA transport:
- > echo rdma 2050 > /proc/fs/nfsd/portlist
+ $ echo rdma 2050 > /proc/fs/nfsd/portlist
- On the client system
- If the NFS/RDMA client was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in kernel config),
- load the RDMA client module:
+ If the NFS/RDMA client was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in
+ kernel config), load the RDMA client module:
- > modprobe xprtrdma.ko
+ $ modprobe xprtrdma.ko
- Regardless of how the client was built (module or built-in), issue the mount.nfs command:
+ Regardless of how the client was built (module or built-in), use this
+ command to mount the NFS/RDMA server:
- > /path/to/your/mount.nfs <IPoIB-server-name-or-address>:/<export> /mnt -i -o rdma,port=2050
+ $ mount -o rdma,port=2050 <IPoIB-server-name-or-address>:/<export> /mnt
- To verify that the mount is using RDMA, run "cat /proc/mounts" and check the
- "proto" field for the given mount.
+ To verify that the mount is using RDMA, run "cat /proc/mounts" and check
+ the "proto" field for the given mount.
Congratulations! You're using NFS/RDMA!
diff --git a/Documentation/filesystems/nfsroot.txt b/Documentation/filesystems/nfsroot.txt
index 31b32917234..68baddf3c3e 100644
--- a/Documentation/filesystems/nfsroot.txt
+++ b/Documentation/filesystems/nfsroot.txt
@@ -169,7 +169,7 @@ They depend on various facilities being available:
3.1) Booting from a floppy using syslinux
When building kernels, an easy way to create a boot floppy that uses
- syslinux is to use the zdisk or bzdisk make targets which use
+ syslinux is to use the zdisk or bzdisk make targets which use zimage
and bzimage images respectively. Both targets accept the
FDARGS parameter which can be used to set the kernel command line.
diff --git a/Documentation/filesystems/ntfs.txt b/Documentation/filesystems/ntfs.txt
index e79ee2db183..ac2a261c5f7 100644
--- a/Documentation/filesystems/ntfs.txt
+++ b/Documentation/filesystems/ntfs.txt
@@ -40,7 +40,7 @@ Web site
========
There is plenty of additional information on the linux-ntfs web site
-at http://linux-ntfs.sourceforge.net/
+at http://www.linux-ntfs.org/
The web site has a lot of additional information, such as a comprehensive
FAQ, documentation on the NTFS on-disk format, information on the Linux-NTFS
@@ -272,7 +272,7 @@ And you would know that /dev/hda2 has a size of 37768814 - 4209030 + 1 =
For Win2k and later dynamic disks, you can for example use the ldminfo utility
which is part of the Linux LDM tools (the latest version at the time of
writing is linux-ldm-0.0.8.tar.bz2). You can download it from:
- http://linux-ntfs.sourceforge.net/downloads.html
+ http://www.linux-ntfs.org/
Simply extract the downloaded archive (tar xvjf linux-ldm-0.0.8.tar.bz2), go
into it (cd linux-ldm-0.0.8) and change to the test directory (cd test). You
will find the precompiled (i386) ldminfo utility there. NOTE: You will not be
diff --git a/Documentation/filesystems/ocfs2.txt b/Documentation/filesystems/ocfs2.txt
index c318a8bbb1e..4340cc82579 100644
--- a/Documentation/filesystems/ocfs2.txt
+++ b/Documentation/filesystems/ocfs2.txt
@@ -76,3 +76,9 @@ localalloc=8(*) Allows custom localalloc size in MB. If the value is too
large, the fs will silently revert it to the default.
Localalloc is not enabled for local mounts.
localflocks This disables cluster aware flock.
+inode64 Indicates that Ocfs2 is allowed to create inodes at
+ any location in the filesystem, including those which
+ will result in inode numbers occupying more than 32
+ bits of significance.
+user_xattr (*) Enables Extended User Attributes.
+nouser_xattr Disables Extended User Attributes.
diff --git a/Documentation/filesystems/omfs.txt b/Documentation/filesystems/omfs.txt
new file mode 100644
index 00000000000..1d0d41ff5c6
--- /dev/null
+++ b/Documentation/filesystems/omfs.txt
@@ -0,0 +1,106 @@
+Optimized MPEG Filesystem (OMFS)
+
+Overview
+========
+
+OMFS is a filesystem created by SonicBlue for use in the ReplayTV DVR
+and Rio Karma MP3 player. The filesystem is extent-based, utilizing
+block sizes from 2k to 8k, with hash-based directories. This
+filesystem driver may be used to read and write disks from these
+devices.
+
+Note, it is not recommended that this FS be used in place of a general
+filesystem for your own streaming media device. Native Linux filesystems
+will likely perform better.
+
+More information is available at:
+
+ http://linux-karma.sf.net/
+
+Various utilities, including mkomfs and omfsck, are included with
+omfsprogs, available at:
+
+ http://bobcopeland.com/karma/
+
+Instructions are included in its README.
+
+Options
+=======
+
+OMFS supports the following mount-time options:
+
+ uid=n - make all files owned by specified user
+ gid=n - make all files owned by specified group
+ umask=xxx - set permission umask to xxx
+ fmask=xxx - set umask to xxx for files
+ dmask=xxx - set umask to xxx for directories
+
+Disk format
+===========
+
+OMFS discriminates between "sysblocks" and normal data blocks. The sysblock
+group consists of super block information, file metadata, directory structures,
+and extents. Each sysblock has a header containing CRCs of the entire
+sysblock, and may be mirrored in successive blocks on the disk. A sysblock may
+have a smaller size than a data block, but since they are both addressed by the
+same 64-bit block number, any remaining space in the smaller sysblock is
+unused.
+
+Sysblock header information:
+
+struct omfs_header {
+ __be64 h_self; /* FS block where this is located */
+ __be32 h_body_size; /* size of useful data after header */
+ __be16 h_crc; /* crc-ccitt of body_size bytes */
+ char h_fill1[2];
+ u8 h_version; /* version, always 1 */
+ char h_type; /* OMFS_INODE_X */
+ u8 h_magic; /* OMFS_IMAGIC */
+ u8 h_check_xor; /* XOR of header bytes before this */
+ __be32 h_fill2;
+};
+
+Files and directories are both represented by omfs_inode:
+
+struct omfs_inode {
+ struct omfs_header i_head; /* header */
+ __be64 i_parent; /* parent containing this inode */
+ __be64 i_sibling; /* next inode in hash bucket */
+ __be64 i_ctime; /* ctime, in milliseconds */
+ char i_fill1[35];
+ char i_type; /* OMFS_[DIR,FILE] */
+ __be32 i_fill2;
+ char i_fill3[64];
+ char i_name[OMFS_NAMELEN]; /* filename */
+ __be64 i_size; /* size of file, in bytes */
+};
+
+Directories in OMFS are implemented as a large hash table. Filenames are
+hashed then prepended into the bucket list beginning at OMFS_DIR_START.
+Lookup requires hashing the filename, then seeking across i_sibling pointers
+until a match is found on i_name. Empty buckets are represented by block
+pointers with all-1s (~0).
+
+A file is an omfs_inode structure followed by an extent table beginning at
+OMFS_EXTENT_START:
+
+struct omfs_extent_entry {
+ __be64 e_cluster; /* start location of a set of blocks */
+ __be64 e_blocks; /* number of blocks after e_cluster */
+};
+
+struct omfs_extent {
+ __be64 e_next; /* next extent table location */
+ __be32 e_extent_count; /* total # extents in this table */
+ __be32 e_fill;
+ struct omfs_extent_entry e_entry; /* start of extent entries */
+};
+
+Each extent holds the block offset followed by number of blocks allocated to
+the extent. The final extent in each table is a terminator with e_cluster
+being ~0 and e_blocks being ones'-complement of the total number of blocks
+in the table.
+
+If this table overflows, a continuation inode is written and pointed to by
+e_next. These have a header but lack the rest of the inode structure.
+
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 7f268f327d7..bcceb99b81d 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -296,6 +296,7 @@ Table 1-4: Kernel info in /proc
uptime System uptime
version Kernel version
video bttv info of video resources (2.4)
+ vmallocinfo Show vmalloced areas
..............................................................................
You can, for example, check which interrupts are currently in use and what
@@ -557,6 +558,49 @@ VmallocTotal: total size of vmalloc memory area
VmallocUsed: amount of vmalloc area which is used
VmallocChunk: largest contigious block of vmalloc area which is free
+..............................................................................
+
+vmallocinfo:
+
+Provides information about vmalloced/vmaped areas. One line per area,
+containing the virtual address range of the area, size in bytes,
+caller information of the creator, and optional information depending
+on the kind of area :
+
+ pages=nr number of pages
+ phys=addr if a physical address was specified
+ ioremap I/O mapping (ioremap() and friends)
+ vmalloc vmalloc() area
+ vmap vmap()ed pages
+ user VM_USERMAP area
+ vpages buffer for pages pointers was vmalloced (huge area)
+ N<node>=nr (Only on NUMA kernels)
+ Number of pages allocated on memory node <node>
+
+> cat /proc/vmallocinfo
+0xffffc20000000000-0xffffc20000201000 2101248 alloc_large_system_hash+0x204 ...
+ /0x2c0 pages=512 vmalloc N0=128 N1=128 N2=128 N3=128
+0xffffc20000201000-0xffffc20000302000 1052672 alloc_large_system_hash+0x204 ...
+ /0x2c0 pages=256 vmalloc N0=64 N1=64 N2=64 N3=64
+0xffffc20000302000-0xffffc20000304000 8192 acpi_tb_verify_table+0x21/0x4f...
+ phys=7fee8000 ioremap
+0xffffc20000304000-0xffffc20000307000 12288 acpi_tb_verify_table+0x21/0x4f...
+ phys=7fee7000 ioremap
+0xffffc2000031d000-0xffffc2000031f000 8192 init_vdso_vars+0x112/0x210
+0xffffc2000031f000-0xffffc2000032b000 49152 cramfs_uncompress_init+0x2e ...
+ /0x80 pages=11 vmalloc N0=3 N1=3 N2=2 N3=3
+0xffffc2000033a000-0xffffc2000033d000 12288 sys_swapon+0x640/0xac0 ...
+ pages=2 vmalloc N1=2
+0xffffc20000347000-0xffffc2000034c000 20480 xt_alloc_table_info+0xfe ...
+ /0x130 [x_tables] pages=4 vmalloc N0=4
+0xffffffffa0000000-0xffffffffa000f000 61440 sys_init_module+0xc27/0x1d00 ...
+ pages=14 vmalloc N2=14
+0xffffffffa000f000-0xffffffffa0014000 20480 sys_init_module+0xc27/0x1d00 ...
+ pages=4 vmalloc N1=4
+0xffffffffa0014000-0xffffffffa0017000 12288 sys_init_module+0xc27/0x1d00 ...
+ pages=2 vmalloc N1=2
+0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 ...
+ pages=10 vmalloc N0=10
1.3 IDE devices in /proc/ide
----------------------------
@@ -879,45 +923,44 @@ CPUs.
The "procs_blocked" line gives the number of processes currently blocked,
waiting for I/O to complete.
+
1.9 Ext4 file system parameters
------------------------------
-Ext4 file system have one directory per partition under /proc/fs/ext4/
-# ls /proc/fs/ext4/hdc/
-group_prealloc max_to_scan mb_groups mb_history min_to_scan order2_req
-stats stream_req
-
-mb_groups:
-This file gives the details of mutiblock allocator buddy cache of free blocks
-
-mb_history:
-Multiblock allocation history.
-stats:
-This file indicate whether the multiblock allocator should start collecting
-statistics. The statistics are shown during unmount
+Information about mounted ext4 file systems can be found in
+/proc/fs/ext4. Each mounted filesystem will have a directory in
+/proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or
+/proc/fs/ext4/dm-0). The files in each per-device directory are shown
+in Table 1-10, below.
-group_prealloc:
-The multiblock allocator normalize the block allocation request to
-group_prealloc filesystem blocks if we don't have strip value set.
-The stripe value can be specified at mount time or during mke2fs.
-
-max_to_scan:
-How long multiblock allocator can look for a best extent (in found extents)
-
-min_to_scan:
-How long multiblock allocator must look for a best extent
-
-order2_req:
-Multiblock allocator use 2^N search using buddies only for requests greater
-than or equal to order2_req. The request size is specfied in file system
-blocks. A value of 2 indicate only if the requests are greater than or equal
-to 4 blocks.
+Table 1-10: Files in /proc/fs/ext4/<devname>
+..............................................................................
+ File Content
+ mb_groups details of multiblock allocator buddy cache of free blocks
+ mb_history multiblock allocation history
+ stats controls whether the multiblock allocator should start
+ collecting statistics, which are shown during the unmount
+ group_prealloc the multiblock allocator will round up allocation
+ requests to a multiple of this tuning parameter if the
+ stripe size is not set in the ext4 superblock
+ max_to_scan The maximum number of extents the multiblock allocator
+ will search to find the best extent
+ min_to_scan The minimum number of extents the multiblock allocator
+ will search to find the best extent
+ order2_req Tuning parameter which controls the minimum size for
+ requests (as a power of 2) where the buddy cache is
+ used
+ stream_req Files which have fewer blocks than this tunable
+ parameter will have their blocks allocated out of a
+ block group specific preallocation pool, so that small
+ files are packed closely together. Each large file
+ will have its blocks allocated out of its own unique
+ preallocation pool.
+inode_readahead Tuning parameter which controls the maximum number of
+ inode table blocks that ext4's inode table readahead
+ algorithm will pre-read into the buffer cache
+..............................................................................
-stream_req:
-Files smaller than stream_req are served by the stream allocator, whose
-purpose is to pack requests as close each to other as possible to
-produce smooth I/O traffic. Avalue of 16 indicate that file smaller than 16
-filesystem block size will use group based preallocation.
------------------------------------------------------------------------------
Summary
@@ -1278,6 +1321,18 @@ debugging information is displayed on console.
NMI switch that most IA32 servers have fires unknown NMI up, for example.
If a system hangs up, try pressing the NMI switch.
+panic_on_unrecovered_nmi
+------------------------
+
+The default Linux behaviour on an NMI of either memory or unknown is to continue
+operation. For many environments such as scientific computing it is preferable
+that the box is taken out and the error dealt with than an uncorrected
+parity/ECC error get propogated.
+
+A small number of systems do generate NMI's for bizarre random reasons such as
+power management so the default is off. That sysctl works like the existing
+panic controls already in that directory.
+
nmi_watchdog
------------
@@ -1288,12 +1343,24 @@ determine whether or not they are still functioning properly.
Because the NMI watchdog shares registers with oprofile, by disabling the NMI
watchdog, oprofile may have more registers to utilize.
-maps_protect
-------------
+msgmni
+------
+
+Maximum number of message queue ids on the system.
+This value scales to the amount of lowmem. It is automatically recomputed
+upon memory add/remove or ipc namespace creation/removal.
+When a value is written into this file, msgmni's value becomes fixed, i.e. it
+is not recomputed anymore when one of the above events occurs.
+Use auto_msgmni to change this behavior.
-Enables/Disables the protection of the per-process proc entries "maps" and
-"smaps". When enabled, the contents of these files are visible only to
-readers that are allowed to ptrace() the given process.
+auto_msgmni
+-----------
+
+Enables/Disables automatic recomputing of msgmni upon memory add/remove or
+upon ipc namespace creation/removal (see the msgmni description above).
+Echoing "1" into this file enables msgmni automatic recomputing.
+Echoing "0" turns it off.
+auto_msgmni default value is 1.
2.4 /proc/sys/vm - The virtual memory subsystem
@@ -1317,15 +1384,18 @@ causes the kernel to prefer to reclaim dentries and inodes.
dirty_background_ratio
----------------------
-Contains, as a percentage of total system memory, the number of pages at which
-the pdflush background writeback daemon will start writing out dirty data.
+Contains, as a percentage of the dirtyable system memory (free pages + mapped
+pages + file cache, not including locked pages and HugePages), the number of
+pages at which the pdflush background writeback daemon will start writing out
+dirty data.
dirty_ratio
-----------------
-Contains, as a percentage of total system memory, the number of pages at which
-a process which is generating disk writes will itself start writing out dirty
-data.
+Contains, as a percentage of the dirtyable system memory (free pages + mapped
+pages + file cache, not including locked pages and HugePages), the number of
+pages at which a process which is generating disk writes will itself start
+writing out dirty data.
dirty_writeback_centisecs
-------------------------
@@ -1430,7 +1500,7 @@ used because pages_free(1355) is smaller than watermark + protection[2]
normal page requirement. If requirement is DMA zone(index=0), protection[0]
(=0) is used.
-zone[i]'s protection[j] is calculated by following exprssion.
+zone[i]'s protection[j] is calculated by following expression.
(i < j):
zone[i]->protection[j]
@@ -2345,22 +2415,29 @@ will be dumped when the <pid> process is dumped. coredump_filter is a bitmask
of memory types. If a bit of the bitmask is set, memory segments of the
corresponding memory type are dumped, otherwise they are not dumped.
-The following 4 memory types are supported:
+The following 7 memory types are supported:
- (bit 0) anonymous private memory
- (bit 1) anonymous shared memory
- (bit 2) file-backed private memory
- (bit 3) file-backed shared memory
+ - (bit 4) ELF header pages in file-backed private memory areas (it is
+ effective only if the bit 2 is cleared)
+ - (bit 5) hugetlb private memory
+ - (bit 6) hugetlb shared memory
Note that MMIO pages such as frame buffer are never dumped and vDSO pages
are always dumped regardless of the bitmask status.
-Default value of coredump_filter is 0x3; this means all anonymous memory
-segments are dumped.
+ Note bit 0-4 doesn't effect any hugetlb memory. hugetlb memory are only
+ effected by bit 5-6.
+
+Default value of coredump_filter is 0x23; this means all anonymous memory
+segments and hugetlb private memory are dumped.
If you don't want to dump all shared memory segments attached to pid 1234,
-write 1 to the process's proc file.
+write 0x21 to the process's proc file.
- $ echo 0x1 > /proc/1234/coredump_filter
+ $ echo 0x21 > /proc/1234/coredump_filter
When a new process is created, the process inherits the bitmask status from its
parent. It is useful to set up coredump_filter before the program runs.
diff --git a/Documentation/filesystems/quota.txt b/Documentation/filesystems/quota.txt
index a590c4093ef..5e8de25bf0f 100644
--- a/Documentation/filesystems/quota.txt
+++ b/Documentation/filesystems/quota.txt
@@ -3,14 +3,14 @@ Quota subsystem
===============
Quota subsystem allows system administrator to set limits on used space and
-number of used inodes (inode is a filesystem structure which is associated
-with each file or directory) for users and/or groups. For both used space and
-number of used inodes there are actually two limits. The first one is called
-softlimit and the second one hardlimit. An user can never exceed a hardlimit
-for any resource. User is allowed to exceed softlimit but only for limited
-period of time. This period is called "grace period" or "grace time". When
-grace time is over, user is not able to allocate more space/inodes until he
-frees enough of them to get below softlimit.
+number of used inodes (inode is a filesystem structure which is associated with
+each file or directory) for users and/or groups. For both used space and number
+of used inodes there are actually two limits. The first one is called softlimit
+and the second one hardlimit. An user can never exceed a hardlimit for any
+resource (unless he has CAP_SYS_RESOURCE capability). User is allowed to exceed
+softlimit but only for limited period of time. This period is called "grace
+period" or "grace time". When grace time is over, user is not able to allocate
+more space/inodes until he frees enough of them to get below softlimit.
Quota limits (and amount of grace time) are set independently for each
filesystem.
@@ -53,6 +53,12 @@ in parentheses):
QUOTA_NL_BSOFTLONGWARN - space (block) softlimit is exceeded
longer than given grace period.
QUOTA_NL_BSOFTWARN - space (block) softlimit
+ - four warnings are also defined for the event when user stops
+ exceeding some limit:
+ QUOTA_NL_IHARDBELOW - inode hardlimit
+ QUOTA_NL_ISOFTBELOW - inode softlimit
+ QUOTA_NL_BHARDBELOW - space (block) hardlimit
+ QUOTA_NL_BSOFTBELOW - space (block) softlimit
QUOTA_NL_A_DEV_MAJOR (u32)
- major number of a device with the affected filesystem
QUOTA_NL_A_DEV_MINOR (u32)
diff --git a/Documentation/filesystems/ramfs-rootfs-initramfs.txt b/Documentation/filesystems/ramfs-rootfs-initramfs.txt
index 7be232b44ee..62fe9b1e089 100644
--- a/Documentation/filesystems/ramfs-rootfs-initramfs.txt
+++ b/Documentation/filesystems/ramfs-rootfs-initramfs.txt
@@ -263,7 +263,7 @@ User Mode Linux, like so:
sleep(999999999);
}
EOF
- gcc -static hello2.c -o init
+ gcc -static hello.c -o init
echo init | cpio -o -H newc | gzip > test.cpio.gz
# Testing external initramfs using the initrd loading mechanism.
qemu -kernel /boot/vmlinuz -initrd test.cpio.gz /dev/zero
diff --git a/Documentation/filesystems/relay.txt b/Documentation/filesystems/relay.txt
index 094f2d2f38b..510b722667a 100644
--- a/Documentation/filesystems/relay.txt
+++ b/Documentation/filesystems/relay.txt
@@ -294,6 +294,16 @@ user-defined data with a channel, and is immediately available
(including in create_buf_file()) via chan->private_data or
buf->chan->private_data.
+Buffer-only channels
+--------------------
+
+These channels have no files associated and can be created with
+relay_open(NULL, NULL, ...). Such channels are useful in scenarios such
+as when doing early tracing in the kernel, before the VFS is up. In these
+cases, one may open a buffer-only channel and then call
+relay_late_setup_files() when the kernel is ready to handle files,
+to expose the buffered data to the userspace.
+
Channel 'modes'
---------------
diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt
index 7f27b8f840d..9e9c348275a 100644
--- a/Documentation/filesystems/sysfs.txt
+++ b/Documentation/filesystems/sysfs.txt
@@ -248,6 +248,7 @@ The top level sysfs directory looks like:
block/
bus/
class/
+dev/
devices/
firmware/
net/
@@ -274,6 +275,11 @@ fs/ contains a directory for some filesystems. Currently each
filesystem wanting to export attributes must create its own hierarchy
below fs/ (see ./fuse.txt for an example).
+dev/ contains two directories char/ and block/. Inside these two
+directories there are symlinks named <major>:<minor>. These symlinks
+point to the sysfs directory for the given device. /sys/dev provides a
+quick way to lookup the sysfs interface for a device from the result of
+a stat(2) operation.
More information can driver-model specific features can be found in
Documentation/driver-model/.
diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt
index 540e9e7f59c..dd84ea3c10d 100644
--- a/Documentation/filesystems/ubifs.txt
+++ b/Documentation/filesystems/ubifs.txt
@@ -57,7 +57,7 @@ Similarly to JFFS2, UBIFS supports on-the-flight compression which makes
it possible to fit quite a lot of data to the flash.
Similarly to JFFS2, UBIFS is tolerant of unclean reboots and power-cuts.
-It does not need stuff like ckfs.ext2. UBIFS automatically replays its
+It does not need stuff like fsck.ext2. UBIFS automatically replays its
journal and recovers from crashes, ensuring that the on-flash data
structures are consistent.
@@ -86,6 +86,15 @@ norm_unmount (*) commit on unmount; the journal is committed
fast_unmount do not commit on unmount; this option makes
unmount faster, but the next mount slower
because of the need to replay the journal.
+bulk_read read more in one go to take advantage of flash
+ media that read faster sequentially
+no_bulk_read (*) do not bulk-read
+no_chk_data_crc skip checking of CRCs on data nodes in order to
+ improve read performance. Use this option only
+ if the flash media is highly reliable. The effect
+ of this option is that corruption of the contents
+ of a file can go unnoticed.
+chk_data_crc (*) do not skip checking CRCs on data nodes
Quick usage instructions
diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index 2d5e1e582e1..bbac4f1d905 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -96,6 +96,14 @@ shortname=lower|win95|winnt|mixed
emulate the Windows 95 rule for create.
Default setting is `lower'.
+tz=UTC -- Interpret timestamps as UTC rather than local time.
+ This option disables the conversion of timestamps
+ between local time (as used by Windows on FAT) and UTC
+ (which Linux uses internally). This is particuluarly
+ useful when mounting devices (like digital cameras)
+ that are set to UTC in order to avoid the pitfalls of
+ local time.
+
<bool>: 0,1,yes,no,true,false
TODO
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index b7522c6cbae..c4d348dabe9 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -143,7 +143,7 @@ struct file_system_type {
The get_sb() method has the following arguments:
- struct file_system_type *fs_type: decribes the filesystem, partly initialized
+ struct file_system_type *fs_type: describes the filesystem, partly initialized
by the specific filesystem code
int flags: mount flags
@@ -895,9 +895,9 @@ struct dentry_operations {
iput() yourself
d_dname: called when the pathname of a dentry should be generated.
- Usefull for some pseudo filesystems (sockfs, pipefs, ...) to delay
+ Useful for some pseudo filesystems (sockfs, pipefs, ...) to delay
pathname generation. (Instead of doing it when dentry is created,
- its done only when the path is needed.). Real filesystems probably
+ it's done only when the path is needed.). Real filesystems probably
dont want to use it, because their dentries are present in global
dcache hash, so their hash should be an invariant. As no lock is
held, d_dname() should not try to modify the dentry itself, unless