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| author | Akira Fujita <a-fujita@rs.jp.nec.com> | 2009-11-23 07:24:41 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-12-14 09:44:52 -0800 |
| commit | a752b960d4b57e0d307e1c40b1b47ab849832c0f (patch) | |
| tree | 676386472245fd3837723d81f8c3dd7e694b1ae7 /fs/ext4 | |
| parent | 52a4345d3d82b77bea320bf223716298468be3de (diff) | |
| download | lwn-a752b960d4b57e0d307e1c40b1b47ab849832c0f.tar.gz lwn-a752b960d4b57e0d307e1c40b1b47ab849832c0f.zip | |
ext4: fix possible recursive locking warning in EXT4_IOC_MOVE_EXT
(cherry picked from commit 49bd22bc4d603a2a4fc2a6a60e156cbea52eb494)
If CONFIG_PROVE_LOCKING is enabled, the double_down_write_data_sem()
will trigger a false-positive warning of a recursive lock. Since we
take i_data_sem for the two inodes ordered by their inode numbers,
this isn't a problem. Use of down_write_nested() will notify the lock
dependency checker machinery that there is no problem here.
This problem was reported by Brian Rogers:
http://marc.info/?l=linux-ext4&m=125115356928011&w=1
Reported-by: Brian Rogers <brian@xyzw.org>
Signed-off-by: Akira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/move_extent.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index a7410b34c5ed..2ca6aa3f34e6 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -189,7 +189,7 @@ double_down_write_data_sem(struct inode *orig_inode, struct inode *donor_inode) } down_write(&EXT4_I(first)->i_data_sem); - down_write(&EXT4_I(second)->i_data_sem); + down_write_nested(&EXT4_I(second)->i_data_sem, SINGLE_DEPTH_NESTING); } /** |