1 files changed, 10 insertions, 2 deletions

diff --git a/fs/ext3/xattr.c b/fs/ext3/xattr.c
index 32e6cc23bd9a..d565759d82ee 100644
--- a/fs/ext3/xattr.c
+++ b/fs/ext3/xattr.c
@@ -803,8 +803,16 @@ inserted:
                         /* We need to allocate a new block */
                         ext3_fsblk_t goal = ext3_group_first_block_no(sb,
                                                 EXT3_I(inode)->i_block_group);
-                        ext3_fsblk_t block = ext3_new_block(handle, inode,
-                                                        goal, &error);
+                        ext3_fsblk_t block;
+
+                        /*
+                         * Protect us agaist concurrent allocations to the
+                         * same inode from ext3_..._writepage(). Reservation
+                         * code does not expect racing allocations.
+                         */
+                        mutex_lock(&EXT3_I(inode)->truncate_mutex);
+                        block = ext3_new_block(handle, inode, goal, &error);
+                        mutex_unlock(&EXT3_I(inode)->truncate_mutex);
                         if (error)
                                 goto cleanup;
                         ea_idebug(inode, "creating block %d", block);