jffs2: hold erase_completion_lock on exit

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 <[email protected]> Cc: [email protected] Signed-off-by: Artem Bityutskiy <[email protected]>
chewitt · Nov 18, 2012 · 2cbba75 · 2cbba75
1 parent d68cbdd
commit 2cbba75
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/fs/jffs2/nodemgmt.c b/fs/jffs2/nodemgmt.c
@@ -417,14 +417,16 @@ static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 			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,