Re: [PATCH 08/24] xfs: fold xfs_istale_done into xfs_iflush_done

Darrick J. Wong
2020-05-22T22:10:55Z

On Fri, May 22, 2020 at 01:50:13PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Having different io completion callbacks for different inode states
> makes things complex. We can detect if the inode is stale via the
> XFS_ISTALE flag in IO completion, so we don't need a special
> callback just for this.
>
> This means inodes only have a single iodone callback, and inode IO
> completion is entirely buffer centric at this point. Hence we no
> longer need to use a log item callback at all as we can just call
> xfs_iflush_done() directly from the buffer completions and walk the
> buffer log item list to complete the all inodes under IO.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

Looking through the iflush machinery always makes my eyes hurt, this
cleans things up nicely.

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

--D

> ---
> fs/xfs/xfs_buf_item.c | 35 ++++++++++++++++++----
> fs/xfs/xfs_inode.c | 6 ++--
> fs/xfs/xfs_inode_item.c | 65 ++++++++++++++---------------------------
> fs/xfs/xfs_inode_item.h | 5 ++--
> 4 files changed, 56 insertions(+), 55 deletions(-)
>
> diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
> index b7ffb117e141e..e376f778bf57c 100644
> --- a/fs/xfs/xfs_buf_item.c
> +++ b/fs/xfs/xfs_buf_item.c
> @@ -13,6 +13,8 @@
> #include "xfs_mount.h"
> #include "xfs_trans.h"
> #include "xfs_buf_item.h"
> +#include "xfs_inode.h"
> +#include "xfs_inode_item.h"
> #include "xfs_trans_priv.h"
> #include "xfs_trace.h"
> #include "xfs_log.h"
> @@ -457,7 +459,8 @@ xfs_buf_item_unpin(
> * the AIL lock.
> */
> if (bip->bli_flags & XFS_BLI_STALE_INODE) {
> - xfs_buf_do_callbacks(bp);
> + lip->li_cb(bp, lip);
> + xfs_iflush_done(bp);
> bp->b_log_item = NULL;
> } else {
> xfs_trans_ail_delete(lip, SHUTDOWN_LOG_IO_ERROR);
> @@ -1141,8 +1144,8 @@ xfs_buf_iodone_callback_error(
> return false;
> }
>
> -static void
> -xfs_buf_run_callbacks(
> +static inline bool
> +xfs_buf_had_callback_errors(
> struct xfs_buf *bp)
> {
>
> @@ -1152,7 +1155,7 @@ xfs_buf_run_callbacks(
> * appropriate action.
> */
> if (bp->b_error && xfs_buf_iodone_callback_error(bp))
> - return;
> + return true;
>
> /*
> * Successful IO or permanent error. Either way, we can clear the
> @@ -1161,7 +1164,16 @@ xfs_buf_run_callbacks(
> bp->b_last_error = 0;
> bp->b_retries = 0;
> bp->b_first_retry_time = 0;
> + return false;
> +}
>
> +static void
> +xfs_buf_run_callbacks(
> + struct xfs_buf *bp)
> +{
> +
> + if (xfs_buf_had_callback_errors(bp))
> + return;
> xfs_buf_do_callbacks(bp);
> bp->b_log_item = NULL;
> }
> @@ -1173,7 +1185,20 @@ void
> xfs_buf_inode_iodone(
> struct xfs_buf *bp)
> {
> - xfs_buf_run_callbacks(bp);
> + struct xfs_buf_log_item *blip = bp->b_log_item;
> + struct xfs_log_item *lip;
> +
> + if (xfs_buf_had_callback_errors(bp))
> + return;
> +
> + /* If there is a buf_log_item attached, run its callback */
> + if (blip) {
> + lip = &blip->bli_item;
> + lip->li_cb(bp, lip);
> + bp->b_log_item = NULL;
> + }
> +
> + xfs_iflush_done(bp);
> xfs_buf_ioend_finish(bp);
> }
>
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 607c9d9bb2b40..c75d625de7945 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;
> - lip->li_cb = xfs_istale_done;
> xfs_trans_ail_copy_lsn(mp->m_ail,
> &iip->ili_flush_lsn,
> &iip->ili_item.li_lsn);
> @@ -2691,8 +2690,7 @@ xfs_ifree_cluster(
> xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
> &iip->ili_item.li_lsn);
>
> - xfs_buf_attach_iodone(bp, xfs_istale_done,
> - &iip->ili_item);
> + xfs_buf_attach_iodone(bp, NULL, &iip->ili_item);
>
> if (ip != free_ip)
> xfs_iunlock(ip, XFS_ILOCK_EXCL);
> @@ -3842,7 +3840,7 @@ xfs_iflush_int(
> * the flush lock.
> */
> bp->b_flags |= _XBF_INODES;
> - xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);
> + xfs_buf_attach_iodone(bp, NULL, &iip->ili_item);
>
> /* generate the checksum. */
> xfs_dinode_calc_crc(mp, dip);
> diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
> index 6ef9cbcfc94a7..7049f2ae8d186 100644
> --- a/fs/xfs/xfs_inode_item.c
> +++ b/fs/xfs/xfs_inode_item.c
> @@ -668,40 +668,34 @@ xfs_inode_item_destroy(
> */
> void
> xfs_iflush_done(
> - struct xfs_buf *bp,
> - struct xfs_log_item *lip)
> + struct xfs_buf *bp)
> {
> struct xfs_inode_log_item *iip;
> - struct xfs_log_item *blip, *n;
> - struct xfs_ail *ailp = lip->li_ailp;
> + struct xfs_log_item *lip, *n;
> + struct xfs_ail *ailp = bp->b_mount->m_ail;
> int need_ail = 0;
> LIST_HEAD(tmp);
>
> /*
> - * Scan the buffer IO completions for other inodes being completed and
> - * attach them to the current inode log item.
> + * Pull the attached inodes from the buffer one at a time and take the
> + * appropriate action on them.
> */
> -
> - list_add_tail(&lip->li_bio_list, &tmp);
> -
> - list_for_each_entry_safe(blip, n, &bp->b_li_list, li_bio_list) {
> - if (lip->li_cb != 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;
> + }
>
> - list_move_tail(&blip->li_bio_list, &tmp);
> + list_move_tail(&lip->li_bio_list, &tmp);
>
> /* Do an unlocked check for needing the AIL lock. */
> - iip = INODE_ITEM(blip);
> - if (blip->li_lsn == iip->ili_flush_lsn ||
> - test_bit(XFS_LI_FAILED, &blip->li_flags))
> + if (lip->li_lsn == iip->ili_flush_lsn ||
> + test_bit(XFS_LI_FAILED, &lip->li_flags))
> need_ail++;
> }
> -
> - /* make sure we capture the state of the initial inode. */
> - iip = INODE_ITEM(lip);
> - if (lip->li_lsn == iip->ili_flush_lsn ||
> - test_bit(XFS_LI_FAILED, &lip->li_flags))
> - need_ail++;
> + ASSERT(list_empty(&bp->b_li_list));
>
> /*
> * We only want to pull the item from the AIL if it is actually there
> @@ -713,19 +707,13 @@ 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 (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
> - * others will be at the same or higher lsn so
> - * we just ignore them.
> - */
> - xfs_lsn_t lsn = xfs_ail_delete_one(ailp, blip);
> + list_for_each_entry(lip, &tmp, li_bio_list) {
> + if (lip->li_lsn == INODE_ITEM(lip)->ili_flush_lsn) {
> + xfs_lsn_t lsn = xfs_ail_delete_one(ailp, lip);
> if (!tail_lsn && lsn)
> tail_lsn = lsn;
> } else {
> - xfs_clear_li_failed(blip);
> + xfs_clear_li_failed(lip);
> }
> }
> xfs_ail_update_finish(ailp, tail_lsn);
> @@ -736,9 +724,9 @@ xfs_iflush_done(
> * 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);
> + list_for_each_entry_safe(lip, n, &tmp, li_bio_list) {
> + list_del_init(&lip->li_bio_list);
> + iip = INODE_ITEM(lip);
>
> spin_lock(&iip->ili_lock);
> iip->ili_last_fields = 0;
> @@ -746,7 +734,6 @@ xfs_iflush_done(
>
> xfs_ifunlock(iip->ili_inode);
> }
> - list_del(&tmp);
> }
>
> /*
> @@ -779,14 +766,6 @@ xfs_iflush_abort(
> xfs_ifunlock(ip);
> }
>
> -void
> -xfs_istale_done(
> - struct xfs_buf *bp,
> - struct xfs_log_item *lip)
> -{
> - xfs_iflush_abort(INODE_ITEM(lip)->ili_inode);
> -}
> -
> /*
> * convert an xfs_inode_log_format struct from the old 32 bit version
> * (which can have different field alignments) to the native 64 bit version
> diff --git a/fs/xfs/xfs_inode_item.h b/fs/xfs/xfs_inode_item.h
> index 1234e8cd3726d..ef427cd03ffc3 100644
> --- a/fs/xfs/xfs_inode_item.h
> +++ b/fs/xfs/xfs_inode_item.h
> @@ -25,15 +25,14 @@ struct xfs_inode_log_item {
> unsigned int ili_fsync_fields; /* logged since last fsync */
> };
>
> -static inline int xfs_inode_clean(xfs_inode_t *ip)
> +static inline int xfs_inode_clean(struct xfs_inode *ip)
> {
> return !ip->i_itemp || !(ip->i_itemp->ili_fields & XFS_ILOG_ALL);
> }
>
> extern void xfs_inode_item_init(struct xfs_inode *, struct xfs_mount *);
> extern void xfs_inode_item_destroy(struct xfs_inode *);
> -extern void xfs_iflush_done(struct xfs_buf *, struct xfs_log_item *);
> -extern void xfs_istale_done(struct xfs_buf *, struct xfs_log_item *);
> +extern void xfs_iflush_done(struct xfs_buf *);
> extern void xfs_iflush_abort(struct xfs_inode *);
> extern int xfs_inode_item_format_convert(xfs_log_iovec_t *,
> struct xfs_inode_log_format *);
> --
> 2.26.2.761.g0e0b3e54be
>