reiserfs: locking, handle nested locks properly

[deliverable/linux.git] / fs / reiserfs / lock.c

diff --git a/fs/reiserfs/lock.c b/fs/reiserfs/lock.c
index d735bc8470e344f8a27021bb46d0c324704ad7f5..045b83ef9fd9d42264fd55af61775abd62843807 100644 (file)
--- a/fs/reiserfs/lock.c
+++ b/fs/reiserfs/lock.c
@@ -48,30 +48,35 @@ void reiserfs_write_unlock(struct super_block *s)
        }
 }
 
-/*
- * If we already own the lock, just exit and don't increase the depth.
- * Useful when we don't want to lock more than once.
- *
- * We always return the lock_depth we had before calling
- * this function.
- */
-int reiserfs_write_lock_once(struct super_block *s)
+int __must_check reiserfs_write_unlock_nested(struct super_block *s)
 {
        struct reiserfs_sb_info *sb_i = REISERFS_SB(s);
+       int depth;
 
-       if (sb_i->lock_owner != current) {
-               mutex_lock(&sb_i->lock);
-               sb_i->lock_owner = current;
-               return sb_i->lock_depth++;
-       }
+       /* this can happen when the lock isn't always held */
+       if (sb_i->lock_owner != current)
+               return -1;
+
+       depth = sb_i->lock_depth;
+
+       sb_i->lock_depth = -1;
+       sb_i->lock_owner = NULL;
+       mutex_unlock(&sb_i->lock);
 
-       return sb_i->lock_depth;
+       return depth;
 }
 
-void reiserfs_write_unlock_once(struct super_block *s, int lock_depth)
+void reiserfs_write_lock_nested(struct super_block *s, int depth)
 {
-       if (lock_depth == -1)
-               reiserfs_write_unlock(s);
+       struct reiserfs_sb_info *sb_i = REISERFS_SB(s);
+
+       /* this can happen when the lock isn't always held */
+       if (depth == -1)
+               return;
+
+       mutex_lock(&sb_i->lock);
+       sb_i->lock_owner = current;
+       sb_i->lock_depth = depth;
 }
 
 /*
@@ -82,9 +87,7 @@ void reiserfs_check_lock_depth(struct super_block *sb, char *caller)
 {
        struct reiserfs_sb_info *sb_i = REISERFS_SB(sb);
 
-       if (sb_i->lock_depth < 0)
-               reiserfs_panic(sb, "%s called without kernel lock held %d",
-                              caller);
+       WARN_ON(sb_i->lock_depth < 0);
 }
 
 #ifdef CONFIG_REISERFS_CHECK