On Thu, Aug 24, 2023 at 03:43:52PM +0800, cheng.lin130@xxxxxxxxxx wrote:
> From: Cheng Lin <cheng.lin130@xxxxxxxxxx>
> An dir nlinks overflow which down form 0 to 0xffffffff, cause the
> directory to become unusable until the next xfs_repair run.
Hmmm. How does this ever happen?
IMO, if it does happen, we need to fix whatever bug that causes it
to happen, not issue a warning and do nothing about the fact we
just hit a corrupt inode state...
> Introduce protection for drop nlink to reduce the impact of this.
> And produce a warning for directory nlink error during remove.
>
> Signed-off-by: Cheng Lin <cheng.lin130@xxxxxxxxxx>
> ---
> fs/xfs/xfs_inode.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 9e62cc5..536dbe4 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -919,6 +919,15 @@ STATIC int xfs_iunlink_remove(struct xfs_trans *tp, struct xfs_perag *pag,
> xfs_trans_t *tp,
> xfs_inode_t *ip)
> {
> + xfs_mount_t *mp;
> +
> + if (VFS_I(ip)->i_nlink == 0) {
> + mp = ip->i_mount;
> + xfs_warn(mp, "%s: Deleting inode %llu with no links.",
> + __func__, ip->i_ino);
> + return 0;
> + }
This is obviously incorrect - whiteout inodes (RENAME_WHITEOUT) have an
i_nlink of zero when they are removed from the unlinked list. As do
O_TMPFILE inodes - when they are linked into the filesystem, we
explicitly check for i_nlink being zero before calling
xfs_iunlink_remove().
> +
> xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
>
> drop_nlink(VFS_I(ip));
Wait a second - this code doesn't match an upstream kernel. What
kernel did you make this patch against?
-Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
