diff options
author | Ingo Molnar <mingo@elte.hu> | 2008-10-12 12:49:27 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-10-12 12:49:27 +0200 |
commit | 1389ac4b976abdc0555280dfc1aa2c3abcc19641 (patch) | |
tree | 1ec51aa0b1e33201f6f4f3bebc657f9ec65f8539 /fs/dlm/user.c | |
parent | 69e13ad56f9e2cd81c4f8bfd6267211c10c14c08 (diff) | |
parent | fd048088306656824958e7783ffcee27e241b361 (diff) |
Merge branch 'linus' into x86/signal
Conflicts:
arch/x86/kernel/signal_64.c
Diffstat (limited to 'fs/dlm/user.c')
-rw-r--r-- | fs/dlm/user.c | 124 |
1 files changed, 94 insertions, 30 deletions
diff --git a/fs/dlm/user.c b/fs/dlm/user.c index 34f14a14fb4..b3832c67194 100644 --- a/fs/dlm/user.c +++ b/fs/dlm/user.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved. + * Copyright (C) 2006-2008 Red Hat, Inc. All rights reserved. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions @@ -15,7 +15,6 @@ #include <linux/poll.h> #include <linux/signal.h> #include <linux/spinlock.h> -#include <linux/smp_lock.h> #include <linux/dlm.h> #include <linux/dlm_device.h> @@ -27,6 +26,8 @@ static const char name_prefix[] = "dlm"; static const struct file_operations device_fops; +static atomic_t dlm_monitor_opened; +static int dlm_monitor_unused = 1; #ifdef CONFIG_COMPAT @@ -340,10 +341,15 @@ static int device_user_deadlock(struct dlm_user_proc *proc, return error; } -static int create_misc_device(struct dlm_ls *ls, char *name) +static int dlm_device_register(struct dlm_ls *ls, char *name) { int error, len; + /* The device is already registered. This happens when the + lockspace is created multiple times from userspace. */ + if (ls->ls_device.name) + return 0; + error = -ENOMEM; len = strlen(name) + strlen(name_prefix) + 2; ls->ls_device.name = kzalloc(len, GFP_KERNEL); @@ -363,6 +369,22 @@ fail: return error; } +int dlm_device_deregister(struct dlm_ls *ls) +{ + int error; + + /* The device is not registered. This happens when the lockspace + was never used from userspace, or when device_create_lockspace() + calls dlm_release_lockspace() after the register fails. */ + if (!ls->ls_device.name) + return 0; + + error = misc_deregister(&ls->ls_device); + if (!error) + kfree(ls->ls_device.name); + return error; +} + static int device_user_purge(struct dlm_user_proc *proc, struct dlm_purge_params *params) { @@ -397,7 +419,7 @@ static int device_create_lockspace(struct dlm_lspace_params *params) if (!ls) return -ENOENT; - error = create_misc_device(ls, params->name); + error = dlm_device_register(ls, params->name); dlm_put_lockspace(ls); if (error) @@ -421,31 +443,22 @@ static int device_remove_lockspace(struct dlm_lspace_params *params) if (!ls) return -ENOENT; - /* Deregister the misc device first, so we don't have - * a device that's not attached to a lockspace. If - * dlm_release_lockspace fails then we can recreate it - */ - error = misc_deregister(&ls->ls_device); - if (error) { - dlm_put_lockspace(ls); - goto out; - } - kfree(ls->ls_device.name); - if (params->flags & DLM_USER_LSFLG_FORCEFREE) force = 2; lockspace = ls->ls_local_handle; + dlm_put_lockspace(ls); - /* dlm_release_lockspace waits for references to go to zero, - so all processes will need to close their device for the ls - before the release will procede */ + /* The final dlm_release_lockspace waits for references to go to + zero, so all processes will need to close their device for the + ls before the release will proceed. release also calls the + device_deregister above. Converting a positive return value + from release to zero means that userspace won't know when its + release was the final one, but it shouldn't need to know. */ - dlm_put_lockspace(ls); error = dlm_release_lockspace(lockspace, force); - if (error) - create_misc_device(ls, ls->ls_name); - out: + if (error > 0) + error = 0; return error; } @@ -623,17 +636,13 @@ static int device_open(struct inode *inode, struct file *file) struct dlm_user_proc *proc; struct dlm_ls *ls; - lock_kernel(); ls = dlm_find_lockspace_device(iminor(inode)); - if (!ls) { - unlock_kernel(); + if (!ls) return -ENOENT; - } proc = kzalloc(sizeof(struct dlm_user_proc), GFP_KERNEL); if (!proc) { dlm_put_lockspace(ls); - unlock_kernel(); return -ENOMEM; } @@ -645,7 +654,6 @@ static int device_open(struct inode *inode, struct file *file) spin_lock_init(&proc->locks_spin); init_waitqueue_head(&proc->wait); file->private_data = proc; - unlock_kernel(); return 0; } @@ -878,9 +886,28 @@ static unsigned int device_poll(struct file *file, poll_table *wait) return 0; } +int dlm_user_daemon_available(void) +{ + /* dlm_controld hasn't started (or, has started, but not + properly populated configfs) */ + + if (!dlm_our_nodeid()) + return 0; + + /* This is to deal with versions of dlm_controld that don't + know about the monitor device. We assume that if the + dlm_controld was started (above), but the monitor device + was never opened, that it's an old version. dlm_controld + should open the monitor device before populating configfs. */ + + if (dlm_monitor_unused) + return 1; + + return atomic_read(&dlm_monitor_opened) ? 1 : 0; +} + static int ctl_device_open(struct inode *inode, struct file *file) { - cycle_kernel_lock(); file->private_data = NULL; return 0; } @@ -890,6 +917,20 @@ static int ctl_device_close(struct inode *inode, struct file *file) return 0; } +static int monitor_device_open(struct inode *inode, struct file *file) +{ + atomic_inc(&dlm_monitor_opened); + dlm_monitor_unused = 0; + return 0; +} + +static int monitor_device_close(struct inode *inode, struct file *file) +{ + if (atomic_dec_and_test(&dlm_monitor_opened)) + dlm_stop_lockspaces(); + return 0; +} + static const struct file_operations device_fops = { .open = device_open, .release = device_close, @@ -913,19 +954,42 @@ static struct miscdevice ctl_device = { .minor = MISC_DYNAMIC_MINOR, }; +static const struct file_operations monitor_device_fops = { + .open = monitor_device_open, + .release = monitor_device_close, + .owner = THIS_MODULE, +}; + +static struct miscdevice monitor_device = { + .name = "dlm-monitor", + .fops = &monitor_device_fops, + .minor = MISC_DYNAMIC_MINOR, +}; + int __init dlm_user_init(void) { int error; + atomic_set(&dlm_monitor_opened, 0); + error = misc_register(&ctl_device); - if (error) + if (error) { log_print("misc_register failed for control device"); + goto out; + } + error = misc_register(&monitor_device); + if (error) { + log_print("misc_register failed for monitor device"); + misc_deregister(&ctl_device); + } + out: return error; } void dlm_user_exit(void) { misc_deregister(&ctl_device); + misc_deregister(&monitor_device); } |