From 3f9749f6e9edcf8ec569fb542efc3be35e06e84a Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Mon, 25 Apr 2016 04:45:02 +0100 Subject: [PATCH] Btrfs: fix empty symlink after creating symlink and fsync parent dir If we create a symlink, fsync its parent directory, crash/power fail and mount the filesystem, we end up with an empty symlink, which not only is useless it's also not allowed in linux (the man page symlink(2) is well explicit about that). So we just need to make sure to fully log an inode if it's a symlink, to ensure its inline extent gets logged, ensuring the same behaviour as ext3, ext4, xfs, reiserfs, f2fs, nilfs2, etc. Example reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ sync $ ln -s /mnt/foo /mnt/testdir/bar $ xfs_io -c fsync /mnt/testdir $ mount /dev/sdb /mnt $ readlink /mnt/testdir/bar A test case for fstests follows soon. Signed-off-by: Filipe Manana --- fs/btrfs/tree-log.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 4709932..a24a0ba 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -5158,7 +5158,7 @@ process_leaf: } ctx->log_new_dentries = false; - if (type == BTRFS_FT_DIR) + if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK) log_mode = LOG_INODE_ALL; btrfs_release_path(path); ret = btrfs_log_inode(trans, root, di_inode, -- 2.7.4