From 0eeca28300df110bd6ed54b31193c83b87921443 Mon Sep 17 00:00:00 2001 From: Robert Love Date: Tue, 12 Jul 2005 17:06:03 -0400 Subject: [PATCH] inotify inotify is intended to correct the deficiencies of dnotify, particularly its inability to scale and its terrible user interface: * dnotify requires the opening of one fd per each directory that you intend to watch. This quickly results in too many open files and pins removable media, preventing unmount. * dnotify is directory-based. You only learn about changes to directories. Sure, a change to a file in a directory affects the directory, but you are then forced to keep a cache of stat structures. * dnotify's interface to user-space is awful. Signals? inotify provides a more usable, simple, powerful solution to file change notification: * inotify's interface is a system call that returns a fd, not SIGIO. You get a single fd, which is select()-able. * inotify has an event that says "the filesystem that the item you were watching is on was unmounted." * inotify can watch directories or files. Inotify is currently used by Beagle (a desktop search infrastructure), Gamin (a FAM replacement), and other projects. See Documentation/filesystems/inotify.txt. Signed-off-by: Robert Love Cc: John McCutchan Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sys_ni.c | 3 +++ kernel/sysctl.c | 43 ++++++++++++++++++++++++++++++++++++++++++- kernel/user.c | 4 ++++ 3 files changed, 49 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 29196ce9b40f..42b40ae5eada 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -80,6 +80,9 @@ cond_syscall(sys_keyctl); cond_syscall(compat_sys_keyctl); cond_syscall(compat_sys_socketcall); cond_syscall(sys_set_zone_reclaim); +cond_syscall(sys_inotify_init); +cond_syscall(sys_inotify_add_watch); +cond_syscall(sys_inotify_rm_watch); /* arch-specific weak syscall entries */ cond_syscall(sys_pciconfig_read); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 270ee7fadbd8..b240e2cb86fc 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -67,6 +67,12 @@ extern int printk_ratelimit_jiffies; extern int printk_ratelimit_burst; extern int pid_max_min, pid_max_max; +#ifdef CONFIG_INOTIFY +extern int inotify_max_user_devices; +extern int inotify_max_user_watches; +extern int inotify_max_queued_events; +#endif + #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) int unknown_nmi_panic; extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *, @@ -218,6 +224,7 @@ static ctl_table root_table[] = { .mode = 0555, .child = dev_table, }, + { .ctl_name = 0 } }; @@ -959,6 +966,40 @@ static ctl_table fs_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, +#ifdef CONFIG_INOTIFY + { + .ctl_name = INOTIFY_MAX_USER_DEVICES, + .procname = "max_user_devices", + .data = &inotify_max_user_devices, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + }, + + { + .ctl_name = INOTIFY_MAX_USER_WATCHES, + .procname = "max_user_watches", + .data = &inotify_max_user_watches, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + }, + + { + .ctl_name = INOTIFY_MAX_QUEUED_EVENTS, + .procname = "max_queued_events", + .data = &inotify_max_queued_events, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero + }, +#endif { .ctl_name = 0 } }; @@ -968,7 +1009,7 @@ static ctl_table debug_table[] = { static ctl_table dev_table[] = { { .ctl_name = 0 } -}; +}; extern void init_irq_proc (void); diff --git a/kernel/user.c b/kernel/user.c index 734575d55769..89e562feb1b1 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -120,6 +120,10 @@ struct user_struct * alloc_uid(uid_t uid) atomic_set(&new->processes, 0); atomic_set(&new->files, 0); atomic_set(&new->sigpending, 0); +#ifdef CONFIG_INOTIFY + atomic_set(&new->inotify_watches, 0); + atomic_set(&new->inotify_devs, 0); +#endif new->mq_bytes = 0; new->locked_shm = 0; -- cgit v1.2.3