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| author | Jan Kara <jack@suse.cz> | 2016-12-21 11:50:39 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2017-04-10 17:37:35 +0200 |
| commit | e7253760587e8523fe1e8ede092a620f1403f2e8 (patch) | |
| tree | 7bcf5c7a849efedfb497da81e044bbe958d88454 /fs | |
| parent | 08991e83b7286635167bab40927665a90fb00d81 (diff) | |
| download | linux-e7253760587e8523fe1e8ede092a620f1403f2e8.tar.gz linux-e7253760587e8523fe1e8ede092a620f1403f2e8.tar.bz2 linux-e7253760587e8523fe1e8ede092a620f1403f2e8.zip | |
inotify: Do not drop mark reference under idr_lock
Dropping mark reference can result in mark being freed. Although it
should not happen in inotify_remove_from_idr() since caller should hold
another reference, just don't risk lock up just after WARN_ON
unnecessarily. Also fold do_inotify_remove_from_idr() into the single
callsite as that function really is just two lines of real code.
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/notify/inotify/inotify_user.c | 24 |
1 files changed, 6 insertions, 18 deletions
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index b82a507a5367..f9113e57ef33 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -395,21 +395,6 @@ static struct inotify_inode_mark *inotify_idr_find(struct fsnotify_group *group, return i_mark; } -static void do_inotify_remove_from_idr(struct fsnotify_group *group, - struct inotify_inode_mark *i_mark) -{ - struct idr *idr = &group->inotify_data.idr; - spinlock_t *idr_lock = &group->inotify_data.idr_lock; - int wd = i_mark->wd; - - assert_spin_locked(idr_lock); - - idr_remove(idr, wd); - - /* removed from the idr, drop that ref */ - fsnotify_put_mark(&i_mark->fsn_mark); -} - /* * Remove the mark from the idr (if present) and drop the reference * on the mark because it was in the idr. @@ -417,6 +402,7 @@ static void do_inotify_remove_from_idr(struct fsnotify_group *group, static void inotify_remove_from_idr(struct fsnotify_group *group, struct inotify_inode_mark *i_mark) { + struct idr *idr = &group->inotify_data.idr; spinlock_t *idr_lock = &group->inotify_data.idr_lock; struct inotify_inode_mark *found_i_mark = NULL; int wd; @@ -468,13 +454,15 @@ static void inotify_remove_from_idr(struct fsnotify_group *group, BUG(); } - do_inotify_remove_from_idr(group, i_mark); + idr_remove(idr, wd); + /* Removed from the idr, drop that ref. */ + fsnotify_put_mark(&i_mark->fsn_mark); out: + i_mark->wd = -1; + spin_unlock(idr_lock); /* match the ref taken by inotify_idr_find_locked() */ if (found_i_mark) fsnotify_put_mark(&found_i_mark->fsn_mark); - i_mark->wd = -1; - spin_unlock(idr_lock); } /* |