On Tue, Nov 26, 2019 at 08:15:17AM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Allow a fatal signal to interrupt us when we're scanning a directory to
> verify a parent pointer.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> fs/xfs/scrub/parent.c | 25 ++++++++++++++++++++-----
> 1 file changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/fs/xfs/scrub/parent.c b/fs/xfs/scrub/parent.c
> index 17100a83e23e..5705adc43a75 100644
> --- a/fs/xfs/scrub/parent.c
> +++ b/fs/xfs/scrub/parent.c
> @@ -32,8 +32,10 @@ xchk_setup_parent(
>
> struct xchk_parent_ctx {
> struct dir_context dc;
> + struct xfs_scrub *sc;
> xfs_ino_t ino;
> xfs_nlink_t nlink;
> + bool cancelled;
> };
>
> /* Look for a single entry in a directory pointing to an inode. */
> @@ -47,11 +49,21 @@ xchk_parent_actor(
> unsigned type)
> {
> struct xchk_parent_ctx *spc;
> + int error = 0;
>
> spc = container_of(dc, struct xchk_parent_ctx, dc);
> if (spc->ino == ino)
> spc->nlink++;
> - return 0;
> +
> + /*
> + * If we're facing a fatal signal, bail out. Store the cancellation
> + * status separately because the VFS readdir code squashes error codes
> + * into short directory reads.
> + */
> + if (xchk_should_terminate(spc->sc, &error))
> + spc->cancelled = true;
> +
> + return error;
> }
>
> /* Count the number of dentries in the parent dir that point to this inode. */
> @@ -62,10 +74,9 @@ xchk_parent_count_parent_dentries(
> xfs_nlink_t *nlink)
> {
> struct xchk_parent_ctx spc = {
> - .dc.actor = xchk_parent_actor,
> - .dc.pos = 0,
> - .ino = sc->ip->i_ino,
> - .nlink = 0,
> + .dc.actor = xchk_parent_actor,
> + .ino = sc->ip->i_ino,
> + .sc = sc,
> };
> size_t bufsize;
> loff_t oldpos;
> @@ -97,6 +108,10 @@ xchk_parent_count_parent_dentries(
> error = xfs_readdir(sc->tp, parent, &spc.dc, bufsize);
> if (error)
> goto out;
> + if (spc.cancelled) {
> + error = -EAGAIN;
> + goto out;
> + }
> if (oldpos == spc.dc.pos)
> break;
> oldpos = spc.dc.pos;
>
