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authorAkira Fujita <a-fujita@rs.jp.nec.com>2009-11-23 07:24:41 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2009-12-14 08:07:26 -0800
commit1cb0b894567626e02ad2fb6d8e74356918624499 (patch)
tree875485bdaa04a096e5d0dd550e330d73d7a8f32f
parentc6b24d6fd81cf34718b0a075e9ce0584e7f6a784 (diff)
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>
-rw-r--r--fs/ext4/move_extent.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 3ec76110373d..db8508fc9858 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);
}
/**