[ 065/221] jffs2: hold erase_completion_lock on exit

Greg Kroah-Hartman
2013-01-15T22:29:14Z

From: Alexey Khoroshilov <khoroshilov@ispras.ru>

commit 2cbba75a56ea78e6876b4e2547a882f10b3fe72b upstream.

Users of jffs2_do_reserve_space() expect they still held
erase_completion_lock after call to it. But there is a path
where jffs2_do_reserve_space() leaves erase_completion_lock unlocked.
The patch fixes it.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/jffs2/nodemgmt.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/fs/jffs2/nodemgmt.c
+++ b/fs/jffs2/nodemgmt.c
@@ -417,14 +417,16 @@ static int jffs2_do_reserve_space(struct
spin_unlock(&c->erase_completion_lock);

ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
- if (ret)
- return ret;
+
/* Just lock it again and continue. Nothing much can change because
we hold c->alloc_sem anyway. In fact, it's not entirely clear why
we hold c->erase_completion_lock in the majority of this function...
but that's a question for another (more caffeine-rich) day. */
spin_lock(&c->erase_completion_lock);

+ if (ret)
+ return ret;
+
waste = jeb->free_size;
jffs2_link_node_ref(c, jeb,
(jeb->offset + c->sector_size - waste) | REF_OBSOLETE,