| From | Andi Kleen <> | Subject | [PATCH] [53/223] reiserfs: fix inode mutex - reiserfs lock misordering | Date | Mon, 13 Dec 2010 00:45:50 +0100 (CET) |
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2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Frederic Weisbecker <fweisbec@gmail.com>
commit da905873effecd1c0166e578bc4b5006f041b18b upstream.
reiserfs_unpack() locks the inode mutex with reiserfs_mutex_lock_safe() to protect against reiserfs lock dependency. However this protection requires to have the reiserfs lock to be locked.
This is the case if reiserfs_unpack() is called by reiserfs_ioctl but not from reiserfs_quota_on() when it tries to unpack tails of quota files.
Fix the ordering of the two locks in reiserfs_unpack() to fix this issue.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reported-by: Markus Gapp <markus.gapp@gmx.net> Reported-by: Jan Kara <jack@suse.cz> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
--- fs/reiserfs/ioctl.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
Index: linux/fs/reiserfs/ioctl.c =================================================================== --- linux.orig/fs/reiserfs/ioctl.c +++ linux/fs/reiserfs/ioctl.c @@ -186,12 +186,11 @@ int reiserfs_unpack(struct inode *inode, return 0; } - /* we need to make sure nobody is changing the file size beneath - ** us - */ - reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb); depth = reiserfs_write_lock_once(inode->i_sb); + /* we need to make sure nobody is changing the file size beneath us */ + reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb); + write_from = inode->i_size & (blocksize - 1); /* if we are on a block boundary, we are already unpacked. */ if (write_from == 0) {
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