ext4: Wait for proper transaction commit on fsync
We cannot rely on buffer dirty bits during fsync because pdflush can come
before fsync is called and clear dirty bits without forcing a transaction
commit. What we do is that we track which transaction has last changed
the inode and which transaction last changed allocation and force it to
disk on fsync.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 5967f18..700206e 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3058,6 +3058,8 @@
if (flags == EXT4_GET_BLOCKS_DIO_CONVERT_EXT) {
ret = ext4_convert_unwritten_extents_dio(handle, inode,
path);
+ if (ret >= 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
goto out2;
}
/* buffered IO case */
@@ -3085,6 +3087,8 @@
ret = ext4_ext_convert_to_initialized(handle, inode,
path, iblock,
max_blocks);
+ if (ret >= 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
out:
if (ret <= 0) {
err = ret;
@@ -3323,10 +3327,16 @@
allocated = ext4_ext_get_actual_len(&newex);
set_buffer_new(bh_result);
- /* Cache only when it is _not_ an uninitialized extent */
- if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)
+ /*
+ * Cache the extent and update transaction to commit on fdatasync only
+ * when it is _not_ an uninitialized extent.
+ */
+ if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
EXT4_EXT_CACHE_EXTENT);
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ } else
+ ext4_update_inode_fsync_trans(handle, inode, 0);
out:
if (allocated > max_blocks)
allocated = max_blocks;