ext4: fix cache flush in ext4_sync_file
We need to flush the write cache unconditionally in ->fsync, otherwise
writes into already allocated blocks can get lost. Writes into fully
allocated files are very common when using disk images for
virtualization, and without this fix can easily lose data after
an fdatasync, which is the typical implementation for a cache flush on
the virtual drive.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 83cf641..ab418c0 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -92,9 +92,9 @@
.nr_to_write = 0, /* sys_fsync did this */
};
ret = sync_inode(inode, &wbc);
- if (journal && (journal->j_flags & JBD2_BARRIER))
- blkdev_issue_flush(inode->i_sb->s_bdev, NULL);
}
out:
+ if (journal && (journal->j_flags & JBD2_BARRIER))
+ blkdev_issue_flush(inode->i_sb->s_bdev, NULL);
return ret;
}