On Wed, Oct 11, 2017 at 06:41:56PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Create a function that can check the shape of a btree -- each block
> passes basic inspection and all the pointers look ok. In the next patch
> we'll add the ability to check the actual keys and records stored within
> the btree. Add some helper functions so that we report detailed scrub
> errors in a uniform manner in dmesg. These are helper functions for
> subsequent patches.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Minor thing:
> /*
> + * Check a btree pointer. Returns true if it's ok to use this pointer.
> + * Callers do not need to set the corrupt flag.
> + */
> +static bool
> +xfs_scrub_btree_ptr_ok(
> + struct xfs_scrub_btree *bs,
> + int level,
> + union xfs_btree_ptr *ptr)
> +{
> + bool res;
> +
> + /* A btree rooted in an inode has no block pointer to the root. */
> + if ((bs->cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
> + level == bs->cur->bc_nlevels)
> + return true;
> +
> + /* Otherwise, check the pointers. */
> + if (bs->cur->bc_flags & XFS_BTREE_LONG_PTRS) {
> + res = xfs_btree_check_lptr(bs->cur, be64_to_cpu(ptr->l), level);
> + if (!res)
> + xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, level);
> + } else {
> + res = xfs_btree_check_sptr(bs->cur, be32_to_cpu(ptr->s), level);
> + if (!res)
> + xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, level);
> + }
We should already know what type of btree we are scrubbing, so I
think this can be simplified to a single
xfs_scrub_btree_set_corrupt() tracepoint.
> +STATIC int
> +xfs_scrub_btree_get_block(
> + struct xfs_scrub_btree *bs,
> + int level,
> + union xfs_btree_ptr *pp,
> + struct xfs_btree_block **pblock,
> + struct xfs_buf **pbp)
> +{
> + void *failed_at;
> + int error;
> +
> + error = xfs_btree_lookup_get_block(bs->cur, level, pp, pblock);
> + if (!xfs_scrub_btree_process_error(bs->sc, bs->cur, level, &error) ||
> + !pblock)
> + return error;
> +
> + xfs_btree_get_block(bs->cur, level, pbp);
> + if (bs->cur->bc_flags & XFS_BTREE_LONG_PTRS) {
> + failed_at = __xfs_btree_check_lblock(bs->cur, *pblock,
> + level, *pbp);
> + if (failed_at) {
> + xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, level);
> + return 0;
> + }
> + } else {
> + failed_at = __xfs_btree_check_sblock(bs->cur, *pblock,
> + level, *pbp);
> + if (failed_at) {
> + xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, level);
> + return 0;
> + }
> + }
And same here.
> diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
> index a7c3361..414bbb8 100644
> --- a/fs/xfs/scrub/common.h
> +++ b/fs/xfs/scrub/common.h
> @@ -21,6 +21,24 @@
> #define __XFS_SCRUB_COMMON_H__
>
> /*
> + * We /could/ terminate a scrub/repair operation early. If we're not
> + * in a good place to continue (fatal signal, etc.) then bail out.
> + * Note that we're careful not to make any judgements about *error.
> + */
> +static inline bool
> +xfs_scrub_should_terminate(
> + struct xfs_scrub_context *sc,
> + int *error)
> +{
> + if (fatal_signal_pending(current)) {
> + if (*error == 0)
> + *error = -EAGAIN;
> + return true;
> + }
> + return false;
> +}
Probably should move that to the original scrub infrastructure
patch.
Otherwise looks fine.
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
--
Dave Chinner
david@xxxxxxxxxxxxx
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