Index: linux-stage/fs/ext3/xattr.c
===================================================================
--- linux-stage.orig/fs/ext3/xattr.c
+++ linux-stage/fs/ext3/xattr.c
@@ -93,7 +93,8 @@
 # define ea_bdebug(f...)
 #endif
 
-static void ext3_xattr_cache_insert(struct buffer_head *);
+static void ext3_xattr_cache_insert(struct super_block *,
+				    struct buffer_head *);
 static struct buffer_head *ext3_xattr_cache_find(struct inode *,
 						 struct ext3_xattr_header *,
 						 struct mb_cache_entry **);
@@ -238,7 +239,7 @@ bad_block:	ext3_error(inode->i_sb, __FUN
 		error = -EIO;
 		goto cleanup;
 	}
-	ext3_xattr_cache_insert(bh);
+	ext3_xattr_cache_insert(inode->i_sb, bh);
 	entry = BFIRST(bh);
 	error = ext3_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
 	if (error == -EIO)
@@ -380,7 +381,7 @@ ext3_xattr_block_list(struct inode *inod
 		error = -EIO;
 		goto cleanup;
 	}
-	ext3_xattr_cache_insert(bh);
+	ext3_xattr_cache_insert(inode->i_sb, bh);
 	error = ext3_xattr_list_entries(inode, BFIRST(bh), buffer, buffer_size);
 
 cleanup:
@@ -479,7 +480,9 @@ ext3_xattr_release_block(handle_t *handl
 {
 	struct mb_cache_entry *ce = NULL;
 
-	ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr);
+	if (!test_opt(inode->i_sb, NO_MBCACHE))
+		ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev,
+					bh->b_blocknr);
 	if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
 		ea_bdebug(bh, "refcount now=0; freeing");
 		if (ce)
@@ -699,8 +702,10 @@ ext3_xattr_block_set(handle_t *handle, s
 	if (i->value && i->value_len > sb->s_blocksize)
 		return -ENOSPC;
 	if (s->base) {
-		ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev,
-					bs->bh->b_blocknr);
+		if (!test_opt(inode->i_sb, NO_MBCACHE))
+			ce = mb_cache_entry_get(ext3_xattr_cache,
+						bs->bh->b_bdev,
+						bs->bh->b_blocknr);
 		if (header(s->base)->h_refcount == cpu_to_le32(1)) {
 			if (ce) {
 				mb_cache_entry_free(ce);
@@ -716,7 +721,7 @@ ext3_xattr_block_set(handle_t *handle, s
 				if (!IS_LAST_ENTRY(s->first))
 					ext3_xattr_rehash(header(s->base),
 							  s->here);
-				ext3_xattr_cache_insert(bs->bh);
+				ext3_xattr_cache_insert(sb, bs->bh);
 			}
 			unlock_buffer(bs->bh);
 			if (error == -EIO)
@@ -797,7 +802,8 @@ inserted:
 				if (error)
 					goto cleanup_dquot;
 			}
-			mb_cache_entry_release(ce);
+			if (ce)
+				mb_cache_entry_release(ce);
 			ce = NULL;
 		} else if (bs->bh && s->base == bs->bh->b_data) {
 			/* We were modifying this block in-place. */
@@ -832,7 +838,7 @@ getblk_failed:
 			memcpy(new_bh->b_data, s->base, new_bh->b_size);
 			set_buffer_uptodate(new_bh);
 			unlock_buffer(new_bh);
-			ext3_xattr_cache_insert(new_bh);
+			ext3_xattr_cache_insert(sb, new_bh);
 			error = ext3_journal_dirty_metadata(handle, new_bh);
 			if (error)
 				goto cleanup;
@@ -1387,12 +1393,15 @@ ext3_xattr_put_super(struct super_block 
  * Returns 0, or a negative error number on failure.
  */
 static void
-ext3_xattr_cache_insert(struct buffer_head *bh)
+ext3_xattr_cache_insert(struct super_block *sb, struct buffer_head *bh)
 {
 	__u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
 	struct mb_cache_entry *ce;
 	int error;
 
+	if (test_opt(sb, NO_MBCACHE))
+		return;
+
 	ce = mb_cache_entry_alloc(ext3_xattr_cache);
 	if (!ce) {
 		ea_bdebug(bh, "out of memory");
@@ -1466,6 +1475,8 @@ ext3_xattr_cache_find(struct inode *inod
 	__u32 hash = le32_to_cpu(header->h_hash);
 	struct mb_cache_entry *ce;
 
+	if (test_opt(inode->i_sb, NO_MBCACHE))
+		return NULL;
 	if (!header->h_hash)
 		return NULL;  /* never share */
 	ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
Index: linux-stage/fs/ext3/super.c
===================================================================
--- linux-stage.orig/fs/ext3/super.c
+++ linux-stage/fs/ext3/super.c
@@ -722,6 +722,7 @@ enum {
 	Opt_grpquota,
 	Opt_extents, Opt_noextents, Opt_bigendian_extents, Opt_extdebug,
 	Opt_mballoc, Opt_nomballoc, Opt_stripe, Opt_maxdirsize, Opt_force_over_8tb,
+	Opt_no_mbcache,
 };
 
 static match_table_t tokens = {
@@ -788,6 +789,7 @@ static match_table_t tokens = {
 	{Opt_force_over_8tb, "force_over_8tb"},
 	{Opt_resize, "resize"},
 	{Opt_maxdirsize, "maxdirsize=%u"},
+	{Opt_no_mbcache, "no_mbcache"},
 	{Opt_err, NULL}
 };
 
@@ -1175,6 +1177,9 @@ clear_qf_name:
 		case Opt_force_over_8tb:
 			force_over_8tb = 1;
 			break;
+		case Opt_no_mbcache:
+			set_opt(sbi->s_mount_opt, NO_MBCACHE);
+			break;
 		default:
 			printk (KERN_ERR
 				"EXT3-fs: Unrecognized mount option \"%s\" "
Index: linux-stage/include/linux/ext3_fs.h
===================================================================
--- linux-stage.orig/include/linux/ext3_fs.h
+++ linux-stage/include/linux/ext3_fs.h
@@ -483,6 +483,8 @@ do {									       \
 #define EXT3_MOUNT_JOURNAL_ASYNC_COMMIT 0x20000000 /* Journal Async Commit */
 #endif
 
+#define EXT3_MOUNT_NO_MBCACHE           0x40000000 /* Disable mbcache */
+
 /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
 #ifndef clear_opt
 #define clear_opt(o, opt)		o &= ~EXT3_MOUNT_##opt