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| author | Naohiro Aota <naota@elisp.net> | 2012-05-29 22:02:24 +0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-05-31 05:04:53 +0400 |
| commit | a4f9a9a635e4d54ac93df4b861ed8792e17bd4a2 (patch) | |
| tree | 40a7145d4d24db3dd26848a8905f710306cbfaa1 | |
| parent | 799243a389bde0de10fa21ca1ca453d2fe538b85 (diff) | |
| download | linux-a4f9a9a635e4d54ac93df4b861ed8792e17bd4a2.tar.xz | |
fsnotify: handle subfiles' perm events
Recently I'm working on fanotify and found the following strange
behaviors.
I wrote a program to set fanotify_mark on "/tmp/block" and FAN_DENY
all events notified.
fanotify_mask = FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD:
$ cd /tmp/block; cat foo
cat: foo: Operation not permitted
Operation on the file is blocked as expected.
But,
fanotify_mask = FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD:
$ cd /tmp/block; cat foo
aaa
It's not blocked anymore. This is confusing behavior. Also reading
commit "fsnotify: call fsnotify_parent in perm events", it seems like
fsnotify should handle subfiles' perm events as well as the other notify
events.
With this patch, regardless of FAN_ALL_EVENTS set or not:
$ cd /tmp/block; cat foo
cat: foo: Operation not permitted
Operation on the file is now blocked properly.
FS_OPEN_PERM and FS_ACCESS_PERM are not listed on FS_EVENTS_POSS_ON_CHILD.
Due to fsnotify_inode_watches_children() check, if you only specify only
these events as fsnotify_mask, you don't get subfiles' perm events
notified.
This patch add the events to FS_EVENTS_POSS_ON_CHILD to get them notified
even if only these events are specified to fsnotify_mask.
Signed-off-by: Naohiro Aota <naota@elisp.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | include/linux/fsnotify_backend.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 91d0e0a34ef3..63d966d5c2ea 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -60,7 +60,7 @@ #define FS_EVENTS_POSS_ON_CHILD (FS_ACCESS | FS_MODIFY | FS_ATTRIB |\ FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN |\ FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE |\ - FS_DELETE) + FS_DELETE | FS_OPEN_PERM | FS_ACCESS_PERM) #define FS_MOVE (FS_MOVED_FROM | FS_MOVED_TO) |