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authorRobert Love <rml@novell.com>2005-07-12 17:06:03 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2005-07-12 20:38:38 -0700
commit0eeca28300df110bd6ed54b31193c83b87921443 (patch)
tree7db42d8a18d80eca538f5b7d25e0532b8fa38b85 /kernel
parentbd4c625c061c2a38568d0add3478f59172455159 (diff)
downloadlinux-0eeca28300df110bd6ed54b31193c83b87921443.tar.bz2
[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 <rml@novell.com> Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sys_ni.c3
-rw-r--r--kernel/sysctl.c43
-rw-r--r--kernel/user.c4
3 files changed, 49 insertions, 1 deletions
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;