reiserfs: fix xattr root locking/refcount bug
The listxattr() and getxattr() operations are only protected by a read lock. As a result, if either of these operations run in parallel, a race condition exists where the xattr_root will end up being cached twice, which results in the leaking of a reference and a BUG() on umount. This patch refactors get_xa_root(), __get_xa_root(), and create_xa_root(), into one get_xa_root() function that takes the appropriate locking around the entire critical section. Reported, diagnosed and tested by Andrea Righi <a.righi@cineca.it> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Cc: Andrea Righi <a.righi@cineca.it> Cc: "Vladimir V. Saveliev" <vs@namesys.com> Cc: Edward Shishkin <edward@namesys.com> Cc: Alex Zarochentsev <zam@namesys.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing
Please register or sign in to comment