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 --- include/linux/fs.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/linux/fs.h') diff --git a/include/linux/fs.h b/include/linux/fs.h index 302ec20838c..c9bf3746a9f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -474,6 +474,11 @@ struct inode { struct dnotify_struct *i_dnotify; /* for directory notifications */ #endif +#ifdef CONFIG_INOTIFY + struct list_head inotify_watches; /* watches on this inode */ + struct semaphore inotify_sem; /* protects the watches list */ +#endif + unsigned long i_state; unsigned long dirtied_when; /* jiffies of first dirtying */ @@ -1393,7 +1398,6 @@ extern void emergency_remount(void); extern int do_remount_sb(struct super_block *sb, int flags, void *data, int force); extern sector_t bmap(struct inode *, sector_t); -extern int setattr_mask(unsigned int); extern int notify_change(struct dentry *, struct iattr *); extern int permission(struct inode *, int, struct nameidata *); extern int generic_permission(struct inode *, int, -- cgit v1.2.3