[PATCH] Extended attribute sharing and debug macro typo fixes

Patch from Andreas Gruenbacher <agruen@suse.de>

Tony Dziedzic has found two bugs in the extended attributes code. Patches with
explanations are attached.

1: Extended attribute sharing on ext2/ext3 not working

   The mb_cache_entry_insert function constantly returns an -EBUSY error
   instead of 0, which causes the xattr cache that is needed by the xattr
   sharing mechanism on ext2/ext3 to not share anything.  This patch fixes
   the problem.  (It is possible that after applying this fix we will hit
   bugs in code that wasn't used before.)

2: Oops in one of the xattr debug statements: The old_bh variable is NULL
   if an inode that previously had no EA's assigned would share an EA block
   with another inode.  (This was hidden by the xattr sharing bug).

fs/ext2/xattr.c

@@ -731,7 +731,7 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
 			 * The old block will be released after updating
 			 * the inode.
 			 */
-			ea_bdebug(old_bh, "reusing block %ld",
+			ea_bdebug(new_bh, "reusing block %ld",
 				new_bh->b_blocknr);
 			
 			error = -EDQUOT;

fs/ext3/xattr.c

@@ -732,7 +732,7 @@ ext3_xattr_set_handle2(handle_t *handle, struct inode *inode,
 			 * The old block will be released after updating
 			 * the inode.
 			 */
-			ea_bdebug(old_bh, "reusing block %ld",
+			ea_bdebug(new_bh, "reusing block %ld",
 				new_bh->b_blocknr);
 			
 			error = -EDQUOT;

fs/mbcache.c

@@ -433,6 +433,7 @@ mb_cache_entry_insert(struct mb_cache_entry *ce, struct block_device *bdev,
 		list_add(&ce->e_indexes[n].o_list,
 			 &cache->c_indexes_hash[n][bucket]);
 	}
+	error = 0;
 out:
 	spin_unlock(&mb_cache_spinlock);
 	return error;