Merge branch 'fix/kconfig' into for-linus

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);