Re: [PATCH 01/24] xfs: remove logged flag from inode log item

Darrick J. Wong
2020-05-22T21:16:00Z

On Fri, May 22, 2020 at 01:50:06PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> This was used to track if the item had logged fields being flushed
> to disk. We log everything in the inode these days, so this logic is
> no longer needed. Remove it.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

AFAICT the only dinode field that isn't tracked through the inode item
is di_next_unlinked, which has always been applied separately (via the
inode cluster buffer).

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
> fs/xfs/xfs_inode.c | 13 ++++---------
> fs/xfs/xfs_inode_item.c | 35 ++++++++++-------------------------
> fs/xfs/xfs_inode_item.h | 1 -
> 3 files changed, 14 insertions(+), 35 deletions(-)
>
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 64f5f9a440aed..ca9f2688b745d 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -2658,7 +2658,6 @@ xfs_ifree_cluster(
> list_for_each_entry(lip, &bp->b_li_list, li_bio_list) {
> if (lip->li_type == XFS_LI_INODE) {
> iip = (struct xfs_inode_log_item *)lip;
> - ASSERT(iip->ili_logged == 1);
> lip->li_cb = xfs_istale_done;
> xfs_trans_ail_copy_lsn(mp->m_ail,
> &iip->ili_flush_lsn,
> @@ -2687,7 +2686,6 @@ xfs_ifree_cluster(
> iip->ili_last_fields = iip->ili_fields;
> iip->ili_fields = 0;
> iip->ili_fsync_fields = 0;
> - iip->ili_logged = 1;
> xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
> &iip->ili_item.li_lsn);
>
> @@ -3819,19 +3817,16 @@ xfs_iflush_int(
> *
> * We can play with the ili_fields bits here, because the inode lock
> * must be held exclusively in order to set bits there and the flush
> - * lock protects the ili_last_fields bits. Set ili_logged so the flush
> - * done routine can tell whether or not to look in the AIL. Also, store
> - * the current LSN of the inode so that we can tell whether the item has
> - * moved in the AIL from xfs_iflush_done(). In order to read the lsn we
> - * need the AIL lock, because it is a 64 bit value that cannot be read
> - * atomically.
> + * lock protects the ili_last_fields bits. Store the current LSN of the
> + * inode so that we can tell whether the item has moved in the AIL from
> + * xfs_iflush_done(). In order to read the lsn we need the AIL lock,
> + * because it is a 64 bit value that cannot be read atomically.
> */
> error = 0;
> flush_out:
> iip->ili_last_fields = iip->ili_fields;
> iip->ili_fields = 0;
> iip->ili_fsync_fields = 0;
> - iip->ili_logged = 1;
>
> xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
> &iip->ili_item.li_lsn);
> diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
> index ba47bf65b772b..b17384aa8df40 100644
> --- a/fs/xfs/xfs_inode_item.c
> +++ b/fs/xfs/xfs_inode_item.c
> @@ -528,8 +528,6 @@ xfs_inode_item_push(
> }
>
> ASSERT(iip->ili_fields != 0 || XFS_FORCED_SHUTDOWN(ip->i_mount));
> - ASSERT(iip->ili_logged == 0 || XFS_FORCED_SHUTDOWN(ip->i_mount));
> -
> spin_unlock(&lip->li_ailp->ail_lock);
>
> error = xfs_iflush(ip, &bp);
> @@ -690,30 +688,24 @@ xfs_iflush_done(
> continue;
>
> list_move_tail(&blip->li_bio_list, &tmp);
> - /*
> - * while we have the item, do the unlocked check for needing
> - * the AIL lock.
> - */
> +
> + /* Do an unlocked check for needing the AIL lock. */
> iip = INODE_ITEM(blip);
> - if ((iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) ||
> + if (blip->li_lsn == iip->ili_flush_lsn ||
> test_bit(XFS_LI_FAILED, &blip->li_flags))
> need_ail++;
> }
>
> /* make sure we capture the state of the initial inode. */
> iip = INODE_ITEM(lip);
> - if ((iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) ||
> + if (lip->li_lsn == iip->ili_flush_lsn ||
> test_bit(XFS_LI_FAILED, &lip->li_flags))
> need_ail++;
>
> /*
> - * We only want to pull the item from the AIL if it is
> - * actually there and its location in the log has not
> - * changed since we started the flush. Thus, we only bother
> - * if the ili_logged flag is set and the inode's lsn has not
> - * changed. First we check the lsn outside
> - * the lock since it's cheaper, and then we recheck while
> - * holding the lock before removing the inode from the AIL.
> + * We only want to pull the item from the AIL if it is actually there
> + * and its location in the log has not changed since we started the
> + * flush. Thus, we only bother if the inode's lsn has not changed.
> */
> if (need_ail) {
> xfs_lsn_t tail_lsn = 0;
> @@ -721,8 +713,7 @@ xfs_iflush_done(
> /* this is an opencoded batch version of xfs_trans_ail_delete */
> spin_lock(&ailp->ail_lock);
> list_for_each_entry(blip, &tmp, li_bio_list) {
> - if (INODE_ITEM(blip)->ili_logged &&
> - blip->li_lsn == INODE_ITEM(blip)->ili_flush_lsn) {
> + if (blip->li_lsn == INODE_ITEM(blip)->ili_flush_lsn) {
> /*
> * xfs_ail_update_finish() only cares about the
> * lsn of the first tail item removed, any
> @@ -740,14 +731,13 @@ xfs_iflush_done(
> }
>
> /*
> - * clean up and unlock the flush lock now we are done. We can clear the
> + * Clean up and unlock the flush lock now we are done. We can clear the
> * ili_last_fields bits now that we know that the data corresponding to
> * them is safely on disk.
> */
> list_for_each_entry_safe(blip, n, &tmp, li_bio_list) {
> list_del_init(&blip->li_bio_list);
> iip = INODE_ITEM(blip);
> - iip->ili_logged = 0;
> iip->ili_last_fields = 0;
> xfs_ifunlock(iip->ili_inode);
> }
> @@ -768,16 +758,11 @@ xfs_iflush_abort(
>
> if (iip) {
> xfs_trans_ail_delete(&iip->ili_item, 0);
> - iip->ili_logged = 0;
> - /*
> - * Clear the ili_last_fields bits now that we know that the
> - * data corresponding to them is safely on disk.
> - */
> - iip->ili_last_fields = 0;
> /*
> * Clear the inode logging fields so no more flushes are
> * attempted.
> */
> + iip->ili_last_fields = 0;
> iip->ili_fields = 0;
> iip->ili_fsync_fields = 0;
> }
> diff --git a/fs/xfs/xfs_inode_item.h b/fs/xfs/xfs_inode_item.h
> index 60b34bb66e8ed..4de5070e07655 100644
> --- a/fs/xfs/xfs_inode_item.h
> +++ b/fs/xfs/xfs_inode_item.h
> @@ -19,7 +19,6 @@ struct xfs_inode_log_item {
> xfs_lsn_t ili_flush_lsn; /* lsn at last flush */
> xfs_lsn_t ili_last_lsn; /* lsn at last transaction */
> unsigned short ili_lock_flags; /* lock flags */
> - unsigned short ili_logged; /* flushed logged data */
> unsigned int ili_last_fields; /* fields when flushed */
> unsigned int ili_fields; /* fields to be logged */
> unsigned int ili_fsync_fields; /* logged since last fsync */
> --
> 2.26.2.761.g0e0b3e54be
>