On Tue, Jun 11, 2019 at 11:48:36PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> In preparation for reusing the iwalk code for the inogrp walking code
> (aka INUMBERS), move the initial inobt lookup and retrieval code out of
> xfs_iwalk_grab_ichunk so that we call the masking code only when we need
> to trim out the inodes that came before the cursor in the inobt record
> (aka BULKSTAT).
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> fs/xfs/xfs_iwalk.c | 79 ++++++++++++++++++++++++++--------------------------
> 1 file changed, 39 insertions(+), 40 deletions(-)
>
>
> diff --git a/fs/xfs/xfs_iwalk.c b/fs/xfs/xfs_iwalk.c
> index a2102fa94ff5..8c4d7e59f86a 100644
> --- a/fs/xfs/xfs_iwalk.c
> +++ b/fs/xfs/xfs_iwalk.c
> @@ -98,43 +98,17 @@ xfs_iwalk_ichunk_ra(
> }
>
> /*
> - * Lookup the inode chunk that the given @agino lives in and then get the
> - * record if we found the chunk. Set the bits in @irec's free mask that
> - * correspond to the inodes before @agino so that we skip them. This is how we
> - * restart an inode walk that was interrupted in the middle of an inode record.
> + * Set the bits in @irec's free mask that correspond to the inodes before
> + * @agino so that we skip them. This is how we restart an inode walk that was
> + * interrupted in the middle of an inode record.
> */
> -STATIC int
> -xfs_iwalk_grab_ichunk(
> - struct xfs_btree_cur *cur, /* btree cursor */
> +STATIC void
> +xfs_iwalk_adjust_start(
> xfs_agino_t agino, /* starting inode of chunk */
> - int *icount,/* return # of inodes grabbed */
> struct xfs_inobt_rec_incore *irec) /* btree record */
> {
> int idx; /* index into inode chunk */
> - int stat;
> int i;
> - int error = 0;
> -
> - /* Lookup the inode chunk that this inode lives in */
> - error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE, &stat);
> - if (error)
> - return error;
> - if (!stat) {
> - *icount = 0;
> - return error;
> - }
> -
> - /* Get the record, should always work */
> - error = xfs_inobt_get_rec(cur, irec, &stat);
> - if (error)
> - return error;
> - XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, stat == 1);
> -
> - /* Check if the record contains the inode in request */
> - if (irec->ir_startino + XFS_INODES_PER_CHUNK <= agino) {
> - *icount = 0;
> - return 0;
> - }
>
> idx = agino - irec->ir_startino;
>
> @@ -149,8 +123,6 @@ xfs_iwalk_grab_ichunk(
> }
>
> irec->ir_free |= xfs_inobt_maskn(0, idx);
> - *icount = irec->ir_count - irec->ir_freecount;
> - return 0;
> }
>
> /* Allocate memory for a walk. */
> @@ -258,7 +230,7 @@ xfs_iwalk_ag_start(
> {
> struct xfs_mount *mp = iwag->mp;
> struct xfs_trans *tp = iwag->tp;
> - int icount;
> + struct xfs_inobt_rec_incore *irec;
> int error;
>
> /* Set up a fresh cursor and empty the inobt cache. */
> @@ -274,15 +246,40 @@ xfs_iwalk_ag_start(
> /*
> * Otherwise, we have to grab the inobt record where we left off, stuff
> * the record into our cache, and then see if there are more records.
> - * We require a lookup cache of at least two elements so that we don't
> - * have to deal with tearing down the cursor to walk the records.
> + * We require a lookup cache of at least two elements so that the
> + * caller doesn't have to deal with tearing down the cursor to walk the
> + * records.
> */
> - error = xfs_iwalk_grab_ichunk(*curpp, agino, &icount,
> - &iwag->recs[iwag->nr_recs]);
> + error = xfs_inobt_lookup(*curpp, agino, XFS_LOOKUP_LE, has_more);
> + if (error)
> + return error;
> +
> + /*
> + * If the LE lookup at @agino yields no records, jump ahead to the
> + * inobt cursor increment to see if there are more records to process.
> + */
> + if (!*has_more)
> + goto out_advance;
> +
> + /* Get the record, should always work */
> + irec = &iwag->recs[iwag->nr_recs];
> + error = xfs_inobt_get_rec(*curpp, irec, has_more);
> if (error)
> return error;
> - if (icount)
> - iwag->nr_recs++;
> + XFS_WANT_CORRUPTED_RETURN(mp, *has_more == 1);
> +
> + /*
> + * If the LE lookup yielded an inobt record before the cursor position,
> + * skip it and see if there's another one after it.
> + */
> + if (irec->ir_startino + XFS_INODES_PER_CHUNK <= agino)
> + goto out_advance;
> +
> + /*
> + * If agino fell in the middle of the inode record, make it look like
> + * the inodes up to agino are free so that we don't return them again.
> + */
> + xfs_iwalk_adjust_start(agino, irec);
>
> /*
> * set_prefetch is supposed to give us a large enough inobt record
> @@ -290,8 +287,10 @@ xfs_iwalk_ag_start(
> * body can cache a record without having to check for cache space
> * until after it reads an inobt record.
> */
> + iwag->nr_recs++;
> ASSERT(iwag->nr_recs < iwag->sz_recs);
>
> +out_advance:
> return xfs_btree_increment(*curpp, 0, has_more);
> }
>
>
