Re: [PATCH 06/22] xfs: convert xfs_iwalk to use perag references

Brian Foster
2021-05-10T13:51:17Z

On Thu, May 06, 2021 at 05:20:38PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Rather than manually walking the ags and passing agnunbers around,
> pass the perag for the AG we are currently working on around in the
> iwalk structure.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---

LGTM:

Reviewed-by: Brian Foster <bfoster@redhat.com>

> fs/xfs/libxfs/xfs_ag.h | 8 +++-
> fs/xfs/xfs_iwalk.c | 86 ++++++++++++++++++++++++++----------------
> 2 files changed, 60 insertions(+), 34 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_ag.h b/fs/xfs/libxfs/xfs_ag.h
> index 33783120263c..3fa88222dacd 100644
> --- a/fs/xfs/libxfs/xfs_ag.h
> +++ b/fs/xfs/libxfs/xfs_ag.h
> @@ -117,13 +117,17 @@ void xfs_perag_put(struct xfs_perag *pag);
> /*
> * Perag iteration APIs
> */
> -#define for_each_perag(mp, next_agno, pag) \
> - for ((next_agno) = 0, (pag) = xfs_perag_get((mp), 0); \
> +#define for_each_perag_from(mp, next_agno, pag) \
> + for ((pag) = xfs_perag_get((mp), (next_agno)); \
> (pag) != NULL; \
> (next_agno) = (pag)->pag_agno + 1, \
> xfs_perag_put(pag), \
> (pag) = xfs_perag_get((mp), (next_agno)))
>
> +#define for_each_perag(mp, next_agno, pag) \
> + (next_agno) = 0; \
> + for_each_perag_from((mp), (next_agno), (pag))
> +
> #define for_each_perag_tag(mp, next_agno, pag, tag) \
> for ((next_agno) = 0, (pag) = xfs_perag_get_tag((mp), 0, (tag)); \
> (pag) != NULL; \
> diff --git a/fs/xfs/xfs_iwalk.c b/fs/xfs/xfs_iwalk.c
> index c4a340f1f1e1..c7e8f48a3ec4 100644
> --- a/fs/xfs/xfs_iwalk.c
> +++ b/fs/xfs/xfs_iwalk.c
> @@ -21,6 +21,7 @@
> #include "xfs_health.h"
> #include "xfs_trans.h"
> #include "xfs_pwork.h"
> +#include "xfs_ag.h"
>
> /*
> * Walking Inodes in the Filesystem
> @@ -51,6 +52,7 @@ struct xfs_iwalk_ag {
>
> struct xfs_mount *mp;
> struct xfs_trans *tp;
> + struct xfs_perag *pag;
>
> /* Where do we start the traversal? */
> xfs_ino_t startino;
> @@ -90,7 +92,7 @@ struct xfs_iwalk_ag {
> STATIC void
> xfs_iwalk_ichunk_ra(
> struct xfs_mount *mp,
> - xfs_agnumber_t agno,
> + struct xfs_perag *pag,
> struct xfs_inobt_rec_incore *irec)
> {
> struct xfs_ino_geometry *igeo = M_IGEO(mp);
> @@ -106,7 +108,7 @@ xfs_iwalk_ichunk_ra(
>
> imask = xfs_inobt_maskn(i, igeo->inodes_per_cluster);
> if (imask & ~irec->ir_free) {
> - xfs_btree_reada_bufs(mp, agno, agbno,
> + xfs_btree_reada_bufs(mp, pag->pag_agno, agbno,
> igeo->blocks_per_cluster,
> &xfs_inode_buf_ops);
> }
> @@ -174,26 +176,25 @@ xfs_iwalk_free(
> /* For each inuse inode in each cached inobt record, call our function. */
> STATIC int
> xfs_iwalk_ag_recs(
> - struct xfs_iwalk_ag *iwag)
> + struct xfs_iwalk_ag *iwag)
> {
> - struct xfs_mount *mp = iwag->mp;
> - struct xfs_trans *tp = iwag->tp;
> - xfs_ino_t ino;
> - unsigned int i, j;
> - xfs_agnumber_t agno;
> - int error;
> + struct xfs_mount *mp = iwag->mp;
> + struct xfs_trans *tp = iwag->tp;
> + struct xfs_perag *pag = iwag->pag;
> + xfs_ino_t ino;
> + unsigned int i, j;
> + int error;
>
> - agno = XFS_INO_TO_AGNO(mp, iwag->startino);
> for (i = 0; i < iwag->nr_recs; i++) {
> struct xfs_inobt_rec_incore *irec = &iwag->recs[i];
>
> - trace_xfs_iwalk_ag_rec(mp, agno, irec);
> + trace_xfs_iwalk_ag_rec(mp, pag->pag_agno, irec);
>
> if (xfs_pwork_want_abort(&iwag->pwork))
> return 0;
>
> if (iwag->inobt_walk_fn) {
> - error = iwag->inobt_walk_fn(mp, tp, agno, irec,
> + error = iwag->inobt_walk_fn(mp, tp, pag->pag_agno, irec,
> iwag->data);
> if (error)
> return error;
> @@ -211,7 +212,8 @@ xfs_iwalk_ag_recs(
> continue;
>
> /* Otherwise call our function. */
> - ino = XFS_AGINO_TO_INO(mp, agno, irec->ir_startino + j);
> + ino = XFS_AGINO_TO_INO(mp, pag->pag_agno,
> + irec->ir_startino + j);
> error = iwag->iwalk_fn(mp, tp, ino, iwag->data);
> if (error)
> return error;
> @@ -257,7 +259,6 @@ xfs_iwalk_del_inobt(
> STATIC int
> xfs_iwalk_ag_start(
> struct xfs_iwalk_ag *iwag,
> - xfs_agnumber_t agno,
> xfs_agino_t agino,
> struct xfs_btree_cur **curpp,
> struct xfs_buf **agi_bpp,
> @@ -265,12 +266,14 @@ xfs_iwalk_ag_start(
> {
> struct xfs_mount *mp = iwag->mp;
> struct xfs_trans *tp = iwag->tp;
> + struct xfs_perag *pag = iwag->pag;
> struct xfs_inobt_rec_incore *irec;
> int error;
>
> /* Set up a fresh cursor and empty the inobt cache. */
> iwag->nr_recs = 0;
> - error = xfs_inobt_cur(mp, tp, agno, XFS_BTNUM_INO, curpp, agi_bpp);
> + error = xfs_inobt_cur(mp, tp, pag->pag_agno, XFS_BTNUM_INO,
> + curpp, agi_bpp);
> if (error)
> return error;
>
> @@ -304,7 +307,7 @@ xfs_iwalk_ag_start(
> if (XFS_IS_CORRUPT(mp, *has_more != 1))
> return -EFSCORRUPTED;
>
> - iwag->lastino = XFS_AGINO_TO_INO(mp, agno,
> + iwag->lastino = XFS_AGINO_TO_INO(mp, pag->pag_agno,
> irec->ir_startino + XFS_INODES_PER_CHUNK - 1);
>
> /*
> @@ -345,7 +348,6 @@ xfs_iwalk_ag_start(
> STATIC int
> xfs_iwalk_run_callbacks(
> struct xfs_iwalk_ag *iwag,
> - xfs_agnumber_t agno,
> struct xfs_btree_cur **curpp,
> struct xfs_buf **agi_bpp,
> int *has_more)
> @@ -376,7 +378,8 @@ xfs_iwalk_run_callbacks(
> return 0;
>
> /* ...and recreate the cursor just past where we left off. */
> - error = xfs_inobt_cur(mp, tp, agno, XFS_BTNUM_INO, curpp, agi_bpp);
> + error = xfs_inobt_cur(mp, tp, iwag->pag->pag_agno, XFS_BTNUM_INO,
> + curpp, agi_bpp);
> if (error)
> return error;
>
> @@ -390,17 +393,17 @@ xfs_iwalk_ag(
> {
> struct xfs_mount *mp = iwag->mp;
> struct xfs_trans *tp = iwag->tp;
> + struct xfs_perag *pag = iwag->pag;
> struct xfs_buf *agi_bp = NULL;
> struct xfs_btree_cur *cur = NULL;
> - xfs_agnumber_t agno;
> xfs_agino_t agino;
> int has_more;
> int error = 0;
>
> /* Set up our cursor at the right place in the inode btree. */
> - agno = XFS_INO_TO_AGNO(mp, iwag->startino);
> + ASSERT(pag->pag_agno == XFS_INO_TO_AGNO(mp, iwag->startino));
> agino = XFS_INO_TO_AGINO(mp, iwag->startino);
> - error = xfs_iwalk_ag_start(iwag, agno, agino, &cur, &agi_bp, &has_more);
> + error = xfs_iwalk_ag_start(iwag, agino, &cur, &agi_bp, &has_more);
>
> while (!error && has_more) {
> struct xfs_inobt_rec_incore *irec;
> @@ -417,7 +420,7 @@ xfs_iwalk_ag(
> break;
>
> /* Make sure that we always move forward. */
> - rec_fsino = XFS_AGINO_TO_INO(mp, agno, irec->ir_startino);
> + rec_fsino = XFS_AGINO_TO_INO(mp, pag->pag_agno, irec->ir_startino);
> if (iwag->lastino != NULLFSINO &&
> XFS_IS_CORRUPT(mp, iwag->lastino >= rec_fsino)) {
> error = -EFSCORRUPTED;
> @@ -438,7 +441,7 @@ xfs_iwalk_ag(
> * walking the inodes.
> */
> if (iwag->iwalk_fn)
> - xfs_iwalk_ichunk_ra(mp, agno, irec);
> + xfs_iwalk_ichunk_ra(mp, pag, irec);
>
> /*
> * If there's space in the buffer for more records, increment
> @@ -458,15 +461,14 @@ xfs_iwalk_ag(
> * we would be if we had been able to increment like above.
> */
> ASSERT(has_more);
> - error = xfs_iwalk_run_callbacks(iwag, agno, &cur, &agi_bp,
> - &has_more);
> + error = xfs_iwalk_run_callbacks(iwag, &cur, &agi_bp, &has_more);
> }
>
> if (iwag->nr_recs == 0 || error)
> goto out;
>
> /* Walk the unprocessed records in the cache. */
> - error = xfs_iwalk_run_callbacks(iwag, agno, &cur, &agi_bp, &has_more);
> + error = xfs_iwalk_run_callbacks(iwag, &cur, &agi_bp, &has_more);
>
> out:
> xfs_iwalk_del_inobt(tp, &cur, &agi_bp, error);
> @@ -555,6 +557,7 @@ xfs_iwalk(
> .pwork = XFS_PWORK_SINGLE_THREADED,
> .lastino = NULLFSINO,
> };
> + struct xfs_perag *pag;
> xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, startino);
> int error;
>
> @@ -565,15 +568,19 @@ xfs_iwalk(
> if (error)
> return error;
>
> - for (; agno < mp->m_sb.sb_agcount; agno++) {
> + for_each_perag_from(mp, agno, pag) {
> + iwag.pag = pag;
> error = xfs_iwalk_ag(&iwag);
> if (error)
> break;
> iwag.startino = XFS_AGINO_TO_INO(mp, agno + 1, 0);
> if (flags & XFS_INOBT_WALK_SAME_AG)
> break;
> + iwag.pag = NULL;
> }
>
> + if (iwag.pag)
> + xfs_perag_put(pag);
> xfs_iwalk_free(&iwag);
> return error;
> }
> @@ -598,6 +605,7 @@ xfs_iwalk_ag_work(
> error = xfs_iwalk_ag(iwag);
> xfs_iwalk_free(iwag);
> out:
> + xfs_perag_put(iwag->pag);
> kmem_free(iwag);
> return error;
> }
> @@ -617,6 +625,7 @@ xfs_iwalk_threaded(
> void *data)
> {
> struct xfs_pwork_ctl pctl;
> + struct xfs_perag *pag;
> xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, startino);
> int error;
>
> @@ -627,7 +636,7 @@ xfs_iwalk_threaded(
> if (error)
> return error;
>
> - for (; agno < mp->m_sb.sb_agcount; agno++) {
> + for_each_perag_from(mp, agno, pag) {
> struct xfs_iwalk_ag *iwag;
>
> if (xfs_pwork_ctl_want_abort(&pctl))
> @@ -635,17 +644,25 @@ xfs_iwalk_threaded(
>
> iwag = kmem_zalloc(sizeof(struct xfs_iwalk_ag), 0);
> iwag->mp = mp;
> +
> + /*
> + * perag is being handed off to async work, so take another
> + * reference for the async work to release.
> + */
> + atomic_inc(&pag->pag_ref);
> + iwag->pag = pag;
> iwag->iwalk_fn = iwalk_fn;
> iwag->data = data;
> iwag->startino = startino;
> iwag->sz_recs = xfs_iwalk_prefetch(inode_records);
> iwag->lastino = NULLFSINO;
> xfs_pwork_queue(&pctl, &iwag->pwork);
> - startino = XFS_AGINO_TO_INO(mp, agno + 1, 0);
> + startino = XFS_AGINO_TO_INO(mp, pag->pag_agno + 1, 0);
> if (flags & XFS_INOBT_WALK_SAME_AG)
> break;
> }
> -
> + if (pag)
> + xfs_perag_put(pag);
> if (polled)
> xfs_pwork_poll(&pctl);
> return xfs_pwork_destroy(&pctl);
> @@ -715,6 +732,7 @@ xfs_inobt_walk(
> .pwork = XFS_PWORK_SINGLE_THREADED,
> .lastino = NULLFSINO,
> };
> + struct xfs_perag *pag;
> xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, startino);
> int error;
>
> @@ -725,15 +743,19 @@ xfs_inobt_walk(
> if (error)
> return error;
>
> - for (; agno < mp->m_sb.sb_agcount; agno++) {
> + for_each_perag_from(mp, agno, pag) {
> + iwag.pag = pag;
> error = xfs_iwalk_ag(&iwag);
> if (error)
> break;
> - iwag.startino = XFS_AGINO_TO_INO(mp, agno + 1, 0);
> + iwag.startino = XFS_AGINO_TO_INO(mp, pag->pag_agno + 1, 0);
> if (flags & XFS_INOBT_WALK_SAME_AG)
> break;
> + iwag.pag = NULL;
> }
>
> + if (iwag.pag)
> + xfs_perag_put(pag);
> xfs_iwalk_free(&iwag);
> return error;
> }
> --
> 2.31.1
>