diff -ru linux-stage.orig/fs/ext4/ext4.h linux-stage/fs/ext4/ext4.h
--- linux-stage.orig/fs/ext4/ext4.h	2012-12-31 15:58:19.000000000 -0500
+++ linux-stage/fs/ext4/ext4.h	2012-12-31 15:58:42.000000000 -0500
@@ -894,7 +894,8 @@
 /*
  * Mount flags
  */
-#define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
+#define EXT4_MOUNT_NO_MBCACHE		0x00001 /* Disable mbcache */
+#define EXT4_MOUNT_OLDALLOC		0x00002 /* Don't use the new Orlov allocator */
 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
diff -ru linux-stage.orig/fs/ext4/super.c linux-stage/fs/ext4/super.c
--- linux-stage.orig/fs/ext4/super.c	2012-12-31 15:58:19.000000000 -0500
+++ linux-stage/fs/ext4/super.c	2012-12-31 15:59:19.000000000 -0500
@@ -1306,6 +1306,7 @@
 	Opt_dioread_nolock, Opt_dioread_lock,
 	Opt_mballoc, Opt_bigendian_extents, Opt_force_over_128tb,
 	Opt_extents, Opt_noextents,
+	Opt_no_mbcache,
 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
 };

@@ -1383,6 +1384,7 @@
 	{Opt_bigendian_extents, "bigendian_extents"},
 	{Opt_force_over_128tb, "force_over_128tb"},
 	{Opt_mballoc, "mballoc"},
+	{Opt_no_mbcache, "no_mbcache"},
 	{Opt_extents, "extents"},
 	{Opt_noextents, "noextents"},
 	{Opt_discard, "discard"},
@@ -1919,6 +1921,9 @@
 			}
 			clear_opt(sb, EXTENTS);
 			break;
+		case Opt_no_mbcache:
+			set_opt(sb, NO_MBCACHE);
+			break;
 		default:
 			ext4_msg(sb, KERN_ERR,
 			       "Unrecognized mount option \"%s\" "
diff -ru linux-stage.orig/fs/ext4/xattr.c linux-stage/fs/ext4/xattr.c
--- linux-stage.orig/fs/ext4/xattr.c	2012-12-31 15:58:19.000000000 -0500
+++ linux-stage/fs/ext4/xattr.c	2012-12-31 16:46:21.000000000 -0500
@@ -86,7 +86,8 @@
 # define ea_bdebug(f...)
 #endif

-static void ext4_xattr_cache_insert(struct buffer_head *);
+static void ext4_xattr_cache_insert(struct super_block *,
+				    struct buffer_head *);
 static struct buffer_head *ext4_xattr_cache_find(struct inode *,
 						 struct ext4_xattr_header *,
 						 struct mb_cache_entry **);
@@ -332,7 +333,7 @@
 		error = -EIO;
 		goto cleanup;
 	}
-	ext4_xattr_cache_insert(bh);
+	ext4_xattr_cache_insert(inode->i_sb, bh);
 	entry = BFIRST(bh);
 	error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1,
 				      inode);
@@ -492,7 +493,7 @@
 		error = -EIO;
 		goto cleanup;
 	}
-	ext4_xattr_cache_insert(bh);
+	ext4_xattr_cache_insert(inode->i_sb, bh);
 	error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);

 cleanup:
@@ -589,7 +590,9 @@
 	struct mb_cache_entry *ce = NULL;
 	int error = 0;

-	ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr);
+	if (!test_opt(inode->i_sb, NO_MBCACHE))
+		ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev,
+					bh->b_blocknr);
 	error = ext4_journal_get_write_access(handle, bh);
 	if (error)
 		goto out;
@@ -989,8 +992,10 @@
 #define header(x) ((struct ext4_xattr_header *)(x))

 	if (s->base) {
-		ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev,
-					bs->bh->b_blocknr);
+		if (!test_opt(inode->i_sb, NO_MBCACHE))
+			ce = mb_cache_entry_get(ext4_xattr_cache,
+						bs->bh->b_bdev,
+						bs->bh->b_blocknr);
 		error = ext4_journal_get_write_access(handle, bs->bh);
 		if (error)
 			goto cleanup;
@@ -1007,7 +1012,7 @@
 				if (!IS_LAST_ENTRY(s->first))
 					ext4_xattr_rehash(header(s->base),
 							  s->here);
-				ext4_xattr_cache_insert(bs->bh);
+				ext4_xattr_cache_insert(sb, bs->bh);
 			}
 			unlock_buffer(bs->bh);
 			if (error == -EIO)
@@ -1090,7 +1095,8 @@
 				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. */
@@ -1141,7 +1147,7 @@
 			memcpy(new_bh->b_data, s->base, new_bh->b_size);
 			set_buffer_uptodate(new_bh);
 			unlock_buffer(new_bh);
-			ext4_xattr_cache_insert(new_bh);
+			ext4_xattr_cache_insert(sb, new_bh);
 			error = ext4_handle_dirty_metadata(handle,
 							   inode, new_bh);
 			if (error)
@@ -1761,12 +1767,15 @@
  * Returns 0, or a negative error number on failure.
  */
 static void
-ext4_xattr_cache_insert(struct buffer_head *bh)
+ext4_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(ext4_xattr_cache, GFP_NOFS);
 	if (!ce) {
 		ea_bdebug(bh, "out of memory");
@@ -1839,6 +1848,8 @@
 	__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);