@@ -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);
Block allocation is called from two places: ext3_get_blocks_handle() and ext3_xattr_block_set(). These two callers are not necessarily synchronized because xattr code holds only xattr_sem and i_mutex, and ext3_get_blocks_handle() may hold only truncate_mutex when called from writepage() path. Block reservation code does not expect two concurrent allocations to happen to the same inode and thus assertions can be triggered or reservation structure corruption can occur. Fix the problem by taking truncate_mutex in xattr code to serialize allocations. CC: Sage Weil <sage@newdream.net> Reported-by: Fyodor Ustinov <ufm@ufm.su> Signed-off-by: Jan Kara <jack@suse.cz> --- fs/ext3/xattr.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) I plan to put this into my tree.