On Tue, Jun 02, 2020 at 07:42:46AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> Rather than attach inodes to the cluster buffer just when we are
> doing IO, attach the inodes to the cluster buffer when they are
> dirtied. The means the buffer always carries a list of dirty inodes
> that reference it, and we can use that list to make more fundamental
> changes to inode writeback that aren't otherwise possible.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Looks straightforward.
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/xfs/libxfs/xfs_trans_inode.c | 9 ++++++---
> fs/xfs/xfs_buf_item.c | 1 +
> fs/xfs/xfs_icache.c | 1 +
> fs/xfs/xfs_inode.c | 24 +++++-------------------
> fs/xfs/xfs_inode_item.c | 14 ++++++++------
> 5 files changed, 21 insertions(+), 28 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_trans_inode.c b/fs/xfs/libxfs/xfs_trans_inode.c
> index 1e7147b90725e..5e7634c13ce78 100644
> --- a/fs/xfs/libxfs/xfs_trans_inode.c
> +++ b/fs/xfs/libxfs/xfs_trans_inode.c
> @@ -164,13 +164,16 @@ xfs_trans_log_inode(
> /*
> * We need an explicit buffer reference for the log item but
> * don't want the buffer to remain attached to the transaction.
> - * Hold the buffer but release the transaction reference.
> + * Hold the buffer but release the transaction reference once
> + * we've attached the inode log item to the buffer log item
> + * list.
> */
> xfs_buf_hold(bp);
> - xfs_trans_brelse(tp, bp);
> -
> spin_lock(&iip->ili_lock);
> iip->ili_item.li_buf = bp;
> + bp->b_flags |= _XBF_INODES;
> + list_add_tail(&iip->ili_item.li_bio_list, &bp->b_li_list);
> + xfs_trans_brelse(tp, bp);
> }
>
> /*
> diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
> index 9739d64a46443..6e7a2d460a675 100644
> --- a/fs/xfs/xfs_buf_item.c
> +++ b/fs/xfs/xfs_buf_item.c
> @@ -465,6 +465,7 @@ xfs_buf_item_unpin(
> if (bip->bli_flags & XFS_BLI_STALE_INODE) {
> xfs_buf_item_done(bp);
> xfs_iflush_done(bp);
> + ASSERT(list_empty(&bp->b_li_list));
> } else {
> xfs_trans_ail_delete(lip, SHUTDOWN_LOG_IO_ERROR);
> xfs_buf_item_relse(bp);
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index 4fe6f250e8448..ed386bc930977 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -115,6 +115,7 @@ __xfs_inode_free(
> {
> /* asserts to verify all state is correct here */
> ASSERT(atomic_read(&ip->i_pincount) == 0);
> + ASSERT(!ip->i_itemp || list_empty(&ip->i_itemp->ili_item.li_bio_list));
> XFS_STATS_DEC(ip->i_mount, vn_active);
>
> call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index fb4c614c64fda..af65acd24ec4e 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -2584,27 +2584,24 @@ xfs_ifree_mark_inode_stale(
> ASSERT(iip->ili_last_fields);
> goto out_iunlock;
> }
> - ASSERT(!iip || list_empty(&iip->ili_item.li_bio_list));
>
> /*
> - * Clean inodes can be released immediately. Everything else has to go
> - * through xfs_iflush_abort() on journal commit as the flock
> - * synchronises removal of the inode from the cluster buffer against
> - * inode reclaim.
> + * Inodes not attached to the buffer can be released immediately.
> + * Everything else has to go through xfs_iflush_abort() on journal
> + * commit as the flock synchronises removal of the inode from the
> + * cluster buffer against inode reclaim.
> */
> - if (xfs_inode_clean(ip)) {
> + if (!iip || list_empty(&iip->ili_item.li_bio_list)) {
> xfs_ifunlock(ip);
> goto out_iunlock;
> }
>
> /* we have a dirty inode in memory that has not yet been flushed. */
> - ASSERT(iip->ili_fields);
> spin_lock(&iip->ili_lock);
> iip->ili_last_fields = iip->ili_fields;
> iip->ili_fields = 0;
> iip->ili_fsync_fields = 0;
> spin_unlock(&iip->ili_lock);
> - list_add_tail(&iip->ili_item.li_bio_list, &bp->b_li_list);
> ASSERT(iip->ili_last_fields);
>
> out_iunlock:
> @@ -3819,19 +3816,8 @@ xfs_iflush_int(
> xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
> &iip->ili_item.li_lsn);
>
> - /*
> - * Attach the inode item callback to the buffer whether the flush
> - * succeeded or not. If not, the caller will shut down and fail I/O
> - * completion on the buffer to remove the inode from the AIL and release
> - * the flush lock.
> - */
> - bp->b_flags |= _XBF_INODES;
> - list_add_tail(&iip->ili_item.li_bio_list, &bp->b_li_list);
> -
> /* generate the checksum. */
> xfs_dinode_calc_crc(mp, dip);
> -
> - ASSERT(!list_empty(&bp->b_li_list));
> return error;
> }
>
> diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
> index 0a7720b7a821a..66675b75de3ec 100644
> --- a/fs/xfs/xfs_inode_item.c
> +++ b/fs/xfs/xfs_inode_item.c
> @@ -665,10 +665,7 @@ xfs_inode_item_destroy(
> *
> * Note: Now that we attach the log item to the buffer when we first log the
> * inode in memory, we can have unflushed inodes on the buffer list here. These
> - * inodes will have a zero ili_last_fields, so skip over them here. We do
> - * this check -after- we've checked for stale inodes, because we're guaranteed
> - * to have XFS_ISTALE set in the case that dirty inodes are in the CIL and have
> - * not yet had their dirtying transactions committed to disk.
> + * inodes will have a zero ili_last_fields, so skip over them here.
> */
> void
> xfs_iflush_done(
> @@ -686,8 +683,8 @@ xfs_iflush_done(
> */
> list_for_each_entry_safe(lip, n, &bp->b_li_list, li_bio_list) {
> iip = INODE_ITEM(lip);
> +
> if (xfs_iflags_test(iip->ili_inode, XFS_ISTALE)) {
> - list_del_init(&lip->li_bio_list);
> xfs_iflush_abort(iip->ili_inode);
> continue;
> }
> @@ -740,12 +737,16 @@ xfs_iflush_done(
> /*
> * Remove the reference to the cluster buffer if the inode is
> * clean in memory. Drop the buffer reference once we've dropped
> - * the locks we hold.
> + * the locks we hold. If the inode is dirty in memory, we need
> + * to put the inode item back on the buffer list for another
> + * pass through the flush machinery.
> */
> ASSERT(iip->ili_item.li_buf == bp);
> if (!iip->ili_fields) {
> iip->ili_item.li_buf = NULL;
> drop_buffer = true;
> + } else {
> + list_add(&lip->li_bio_list, &bp->b_li_list);
> }
> iip->ili_last_fields = 0;
> iip->ili_flush_lsn = 0;
> @@ -789,6 +790,7 @@ xfs_iflush_abort(
> iip->ili_flush_lsn = 0;
> bp = iip->ili_item.li_buf;
> iip->ili_item.li_buf = NULL;
> + list_del_init(&iip->ili_item.li_bio_list);
> spin_unlock(&iip->ili_lock);
> }
> xfs_ifunlock(ip);
> --
> 2.26.2.761.g0e0b3e54be
>
