From: Akira Fujita Date: Mon, 23 Nov 2009 12:24:41 +0000 (-0500) Subject: ext4: fix possible recursive locking warning in EXT4_IOC_MOVE_EXT X-Git-Tag: v2.6.31.8~30 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1cb0b894567626e02ad2fb6d8e74356918624499;p=thirdparty%2Fkernel%2Fstable.git 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 Signed-off-by: Akira Fujita Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 3ec76110373d1..db8508fc9858f 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); } /**