Commit ece95912db94d98e202cbedb8f35206deb29d83d
Committed by
Linus Torvalds
Linus Torvalds
1 parent
6d98516181
Exists in
master
and in
20 other branches
inotify: send IN_ATTRIB events when link count changes
Currently, no notification event has been sent when inode's link count
changed. This is inconvenient for the application in some cases:
Suppose you have the following directory structure
foo/test
bar/
and you watch test. If someone does "mv foo/test bar/", you get event
IN_MOVE_SELF and you know something has happened with the file "test".
However if someone does "ln foo/test bar/test" and "rm foo/test" you get no
inotify event for the file "test" (only directories "foo" and "bar" receive
events).
Furthermore it could be argued that link count belongs to file's metadata and
thus IN_ATTRIB should be sent when it changes.
The following patch implements sending of IN_ATTRIB inotify events when link
count of the inode changes, i.e., when a hardlink to the inode is created or
when it is removed. This event is sent in addition to all the events sent so
far. In particular, when a last link to a file is removed, IN_ATTRIB event is
sent in addition to IN_DELETE_SELF event.
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Morten Welinder <mwelinder@gmail.com>
Cc: Robert Love <rlove@google.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 2 changed files with 24 additions and 1 deletions Side-by-side Diff
fs/namei.c
| ... | ... | @@ -2188,6 +2188,7 @@ |
| 2188 | 2188 | |
| 2189 | 2189 | /* We don't d_delete() NFS sillyrenamed files--they still exist. */ |
| 2190 | 2190 | if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) { |
| 2191 | + fsnotify_link_count(dentry->d_inode); | |
| 2191 | 2192 | d_delete(dentry); |
| 2192 | 2193 | } |
| 2193 | 2194 | |
| ... | ... | @@ -2360,7 +2361,7 @@ |
| 2360 | 2361 | error = dir->i_op->link(old_dentry, dir, new_dentry); |
| 2361 | 2362 | mutex_unlock(&old_dentry->d_inode->i_mutex); |
| 2362 | 2363 | if (!error) |
| 2363 | - fsnotify_create(dir, new_dentry); | |
| 2364 | + fsnotify_link(dir, old_dentry->d_inode, new_dentry); | |
| 2364 | 2365 | return error; |
| 2365 | 2366 | } |
| 2366 | 2367 |
include/linux/fsnotify.h
| ... | ... | @@ -92,6 +92,14 @@ |
| 92 | 92 | } |
| 93 | 93 | |
| 94 | 94 | /* |
| 95 | + * fsnotify_link_count - inode's link count changed | |
| 96 | + */ | |
| 97 | +static inline void fsnotify_link_count(struct inode *inode) | |
| 98 | +{ | |
| 99 | + inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL); | |
| 100 | +} | |
| 101 | + | |
| 102 | +/* | |
| 95 | 103 | * fsnotify_create - 'name' was linked in |
| 96 | 104 | */ |
| 97 | 105 | static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) |
| ... | ... | @@ -100,6 +108,20 @@ |
| 100 | 108 | inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name, |
| 101 | 109 | dentry->d_inode); |
| 102 | 110 | audit_inode_child(dentry->d_name.name, dentry, inode); |
| 111 | +} | |
| 112 | + | |
| 113 | +/* | |
| 114 | + * fsnotify_link - new hardlink in 'inode' directory | |
| 115 | + * Note: We have to pass also the linked inode ptr as some filesystems leave | |
| 116 | + * new_dentry->d_inode NULL and instantiate inode pointer later | |
| 117 | + */ | |
| 118 | +static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry) | |
| 119 | +{ | |
| 120 | + inode_dir_notify(dir, DN_CREATE); | |
| 121 | + inotify_inode_queue_event(dir, IN_CREATE, 0, new_dentry->d_name.name, | |
| 122 | + inode); | |
| 123 | + fsnotify_link_count(inode); | |
| 124 | + audit_inode_child(new_dentry->d_name.name, new_dentry, dir); | |
| 103 | 125 | } |
| 104 | 126 | |
| 105 | 127 | /* |