On 19.01.2018 16:08, Carlos Maiolino wrote:
> Now that buffer's b_fspriv has been split, just replace the current
> singly linked list of xfs_log_items, by the list_head infrastructure.
>
> Also, remove the xfs_log_item argument from xfs_buf_resubmit_failed_buffers(),
> there is no need for this argument, once the log items can be walked
> through the list_head in the buffer.
>
> Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
> ---
> fs/xfs/xfs_buf.c | 1 +
> fs/xfs/xfs_buf.h | 2 +-
> fs/xfs/xfs_buf_item.c | 60 +++++++++++++++++++++----------------------------
> fs/xfs/xfs_buf_item.h | 1 -
> fs/xfs/xfs_dquot_item.c | 2 +-
> fs/xfs/xfs_inode.c | 8 +++----
> fs/xfs/xfs_inode_item.c | 41 ++++++++++-----------------------
> fs/xfs/xfs_log.c | 1 +
> fs/xfs/xfs_trans.h | 2 +-
> 9 files changed, 46 insertions(+), 72 deletions(-)
>
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index 07dccb05e782..47e530662db9 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -236,6 +236,7 @@ _xfs_buf_alloc(
> init_completion(&bp->b_iowait);
> INIT_LIST_HEAD(&bp->b_lru);
> INIT_LIST_HEAD(&bp->b_list);
> + INIT_LIST_HEAD(&bp->b_li_list);
> sema_init(&bp->b_sema, 0); /* held, no waiters */
> spin_lock_init(&bp->b_lock);
> XB_SET_OWNER(bp);
> diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
> index 21a20d91e9e9..503221f778d3 100644
> --- a/fs/xfs/xfs_buf.h
> +++ b/fs/xfs/xfs_buf.h
> @@ -177,7 +177,7 @@ struct xfs_buf {
> xfs_buf_iodone_t b_iodone; /* I/O completion function */
> struct completion b_iowait; /* queue for I/O waiters */
> void *b_log_item;
> - struct xfs_log_item *b_li_list;
> + struct list_head b_li_list; /* Log items list head */
> struct xfs_trans *b_transp;
> struct page **b_pages; /* array of page pointers */
> struct page *b_page_array[XB_PAGES]; /* inline pages */
> diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
> index cbb88a671b3a..33f878b51925 100644
> --- a/fs/xfs/xfs_buf_item.c
> +++ b/fs/xfs/xfs_buf_item.c
> @@ -457,7 +457,7 @@ xfs_buf_item_unpin(
> if (bip->bli_flags & XFS_BLI_STALE_INODE) {
> xfs_buf_do_callbacks(bp);
> bp->b_log_item = NULL;
> - bp->b_li_list = NULL;
> + list_del_init(&bp->b_li_list);
> bp->b_iodone = NULL;
> } else {
> spin_lock(&ailp->xa_lock);
> @@ -955,13 +955,12 @@ xfs_buf_item_relse(
> struct xfs_buf *bp)
> {
> struct xfs_buf_log_item *bip = bp->b_log_item;
> - struct xfs_log_item *lip = bp->b_li_list;
>
> trace_xfs_buf_item_relse(bp, _RET_IP_);
> ASSERT(!(bip->bli_item.li_flags & XFS_LI_IN_AIL));
>
> bp->b_log_item = NULL;
> - if (lip == NULL)
> + if (list_empty(&bp->b_li_list))
> bp->b_iodone = NULL;
>
> xfs_buf_rele(bp);
> @@ -982,18 +981,10 @@ xfs_buf_attach_iodone(
> void (*cb)(struct xfs_buf *, xfs_log_item_t *),
> xfs_log_item_t *lip)
> {
> - xfs_log_item_t *head_lip;
> -
> ASSERT(xfs_buf_islocked(bp));
>
> lip->li_cb = cb;
> - head_lip = bp->b_li_list;
> - if (head_lip) {
> - lip->li_bio_list = head_lip->li_bio_list;
> - head_lip->li_bio_list = lip;
> - } else {
> - bp->b_li_list = lip;
> - }
> + list_add_tail(&lip->li_bio_list, &bp->b_li_list);
>
> ASSERT(bp->b_iodone == NULL ||
> bp->b_iodone == xfs_buf_iodone_callbacks);
> @@ -1003,12 +994,12 @@ xfs_buf_attach_iodone(
> /*
> * We can have many callbacks on a buffer. Running the callbacks individually
> * can cause a lot of contention on the AIL lock, so we allow for a single
> - * callback to be able to scan the remaining lip->li_bio_list for other items
> + * callback to be able to scan the remaining items in bp->b_li_list for other items
> * of the same type and callback to be processed in the first call.
> *
> * As a result, the loop walking the callback list below will also modify the
> * list. it removes the first item from the list and then runs the callback.
> - * The loop then restarts from the new head of the list. This allows the
> + * The loop then restarts from the new first item int the list. This allows the
> * callback to scan and modify the list attached to the buffer and we don't
> * have to care about maintaining a next item pointer.
> */
> @@ -1025,17 +1016,19 @@ xfs_buf_do_callbacks(
> lip->li_cb(bp, lip);
> }
>
> - while ((lip = bp->b_li_list) != NULL) {
> - bp->b_li_list = lip->li_bio_list;
> - ASSERT(lip->li_cb != NULL);
> + while(!list_empty(&bp->b_li_list))
> + {
nit: Since you are iterating the list why not the canonical
list_for_each_entry_safe it will also obviate the need for
list_first_entry.
> + lip = list_first_entry(&bp->b_li_list, struct xfs_log_item,
> + li_bio_list);
> +
> /*
> - * Clear the next pointer so we don't have any
> + * Remove the item from the list, so we don't have any
> * confusion if the item is added to another buf.
> * Don't touch the log item after calling its
> * callback, because it could have freed itself.
> */
> - lip->li_bio_list = NULL;
> - lip->li_cb(bp, lip);
> + list_del_init(&lip->li_bio_list);
> + lip->li_cb(bp,lip);
> }
> }
>
> @@ -1051,8 +1044,7 @@ STATIC void
> xfs_buf_do_callbacks_fail(
> struct xfs_buf *bp)
> {
> - struct xfs_log_item *lip = bp->b_li_list;
> - struct xfs_log_item *next;
> + struct xfs_log_item *lip;
> struct xfs_ail *ailp;
>
> /*
> @@ -1060,14 +1052,16 @@ xfs_buf_do_callbacks_fail(
> * and xfs_buf_iodone_callback_error, and they have no IO error
> * callbacks. Check only for items in b_li_list.
> */
> - if (lip == NULL)
> + if (list_empty(&bp->b_li_list)) {
> return;
> - else
> + } else {
> + lip = list_first_entry(&bp->b_li_list, struct xfs_log_item,
> + li_bio_list);
> ailp = lip->li_ailp;
> + }
>
> spin_lock(&ailp->xa_lock);
> - for (; lip; lip = next) {
> - next = lip->li_bio_list;
> + list_for_each_entry(lip, &bp->b_li_list, li_bio_list) {
> if (lip->li_ops->iop_error)
> lip->li_ops->iop_error(lip, bp);
> }
> @@ -1079,7 +1073,7 @@ xfs_buf_iodone_callback_error(
> struct xfs_buf *bp)
> {
> struct xfs_buf_log_item *bip = bp->b_log_item;
> - struct xfs_log_item *lip = bp->b_li_list;
> + struct xfs_log_item *lip;
> struct xfs_mount *mp;
> static ulong lasttime;
> static xfs_buftarg_t *lasttarg;
> @@ -1089,7 +1083,8 @@ xfs_buf_iodone_callback_error(
> * The failed buffer might not have a buf_log_item attached or the
> * log_item list might be empty. Get the mp from the available xfs_log_item
> */
> - if (bip == NULL)
> + if ((lip = list_first_entry_or_null(&bp->b_li_list, struct xfs_log_item,
> + li_bio_list)))
> mp = lip->li_mountp;
> else
> mp = bip->bli_item.li_mountp;
> @@ -1203,7 +1198,7 @@ xfs_buf_iodone_callbacks(
>
> xfs_buf_do_callbacks(bp);
> bp->b_log_item = NULL;
> - bp->b_li_list = NULL;
> + list_del_init(&bp->b_li_list);
> bp->b_iodone = NULL;
> xfs_buf_ioend(bp);
> }
> @@ -1248,10 +1243,9 @@ xfs_buf_iodone(
> bool
> xfs_buf_resubmit_failed_buffers(
> struct xfs_buf *bp,
> - struct xfs_log_item *lip,
> struct list_head *buffer_list)
> {
> - struct xfs_log_item *next;
> + struct xfs_log_item *lip;
>
> /*
> * Clear XFS_LI_FAILED flag from all items before resubmit
> @@ -1259,10 +1253,8 @@ xfs_buf_resubmit_failed_buffers(
> * XFS_LI_FAILED set/clear is protected by xa_lock, caller this
> * function already have it acquired
> */
> - for (; lip; lip = next) {
> - next = lip->li_bio_list;
> + list_for_each_entry(lip, &bp->b_li_list, li_bio_list)
> xfs_clear_li_failed(lip);
> - }
>
> /* Add this buffer back to the delayed write list */
> return xfs_buf_delwri_queue(bp, buffer_list);
> diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
> index 0febfbbf6ba9..643f53dcfe51 100644
> --- a/fs/xfs/xfs_buf_item.h
> +++ b/fs/xfs/xfs_buf_item.h
> @@ -71,7 +71,6 @@ void xfs_buf_attach_iodone(struct xfs_buf *,
> void xfs_buf_iodone_callbacks(struct xfs_buf *);
> void xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *);
> bool xfs_buf_resubmit_failed_buffers(struct xfs_buf *,
> - struct xfs_log_item *,
> struct list_head *);
>
> extern kmem_zone_t *xfs_buf_item_zone;
> diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c
> index 664dea105e76..4a4539a4fad5 100644
> --- a/fs/xfs/xfs_dquot_item.c
> +++ b/fs/xfs/xfs_dquot_item.c
> @@ -179,7 +179,7 @@ xfs_qm_dquot_logitem_push(
> if (!xfs_buf_trylock(bp))
> return XFS_ITEM_LOCKED;
>
> - if (!xfs_buf_resubmit_failed_buffers(bp, lip, buffer_list))
> + if (!xfs_buf_resubmit_failed_buffers(bp, buffer_list))
> rval = XFS_ITEM_FLUSHING;
>
> xfs_buf_unlock(bp);
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 0a4c2e48402f..8e26d3121be6 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -2214,7 +2214,7 @@ xfs_ifree_cluster(
> struct xfs_buf *bp;
> xfs_inode_t *ip;
> xfs_inode_log_item_t *iip;
> - xfs_log_item_t *lip;
> + struct xfs_log_item *lip;
> struct xfs_perag *pag;
> xfs_ino_t inum;
>
> @@ -2272,8 +2272,7 @@ xfs_ifree_cluster(
> * stale first, we will not attempt to lock them in the loop
> * below as the XFS_ISTALE flag will be set.
> */
> - lip = bp->b_li_list;
> - while (lip) {
> + list_for_each_entry(lip, &bp->b_li_list, li_bio_list) {
> if (lip->li_type == XFS_LI_INODE) {
> iip = (xfs_inode_log_item_t *)lip;
> ASSERT(iip->ili_logged == 1);
> @@ -2283,7 +2282,6 @@ xfs_ifree_cluster(
> &iip->ili_item.li_lsn);
> xfs_iflags_set(iip->ili_inode, XFS_ISTALE);
> }
> - lip = lip->li_bio_list;
> }
>
>
> @@ -3649,7 +3647,7 @@ xfs_iflush_int(
> /* generate the checksum. */
> xfs_dinode_calc_crc(mp, dip);
>
> - ASSERT(bp->b_li_list != NULL);
> + ASSERT(!list_empty(&bp->b_li_list));
> ASSERT(bp->b_iodone != NULL);
> return 0;
>
> diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
> index 993736032b4b..ddfc2c80af5e 100644
> --- a/fs/xfs/xfs_inode_item.c
> +++ b/fs/xfs/xfs_inode_item.c
> @@ -521,7 +521,7 @@ xfs_inode_item_push(
> if (!xfs_buf_trylock(bp))
> return XFS_ITEM_LOCKED;
>
> - if (!xfs_buf_resubmit_failed_buffers(bp, lip, buffer_list))
> + if (!xfs_buf_resubmit_failed_buffers(bp, buffer_list))
> rval = XFS_ITEM_FLUSHING;
>
> xfs_buf_unlock(bp);
> @@ -712,37 +712,23 @@ xfs_iflush_done(
> struct xfs_log_item *lip)
> {
> struct xfs_inode_log_item *iip;
> - struct xfs_log_item *blip;
> - struct xfs_log_item *next;
> - struct xfs_log_item *prev;
> + struct xfs_log_item *blip, *n;
> struct xfs_ail *ailp = lip->li_ailp;
> 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.
> */
> - blip = bp->b_li_list;
> - prev = NULL;
> - while (blip != NULL) {
> - if (blip->li_cb != xfs_iflush_done) {
> - prev = blip;
> - blip = blip->li_bio_list;
> - continue;
> - }
>
> - /* remove from list */
> - next = blip->li_bio_list;
> - if (!prev) {
> - bp->b_li_list = next;
> - } else {
> - prev->li_bio_list = next;
> - }
> + list_add_tail(&lip->li_bio_list, &tmp);
>
> - /* add to current list */
> - blip->li_bio_list = lip->li_bio_list;
> - lip->li_bio_list = blip;
> + list_for_each_entry_safe(blip, n, &bp->b_li_list, li_bio_list) {
> + if (lip->li_cb != 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.
> @@ -751,8 +737,6 @@ xfs_iflush_done(
> if ((iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) ||
> (blip->li_flags & XFS_LI_FAILED))
> need_ail++;
> -
> - blip = next;
> }
>
> /* make sure we capture the state of the initial inode. */
> @@ -775,7 +759,7 @@ xfs_iflush_done(
>
> /* this is an opencoded batch version of xfs_trans_ail_delete */
> spin_lock(&ailp->xa_lock);
> - for (blip = lip; blip; blip = blip->li_bio_list) {
> + list_for_each_entry(blip, &tmp, li_bio_list) {
> if (INODE_ITEM(blip)->ili_logged &&
> blip->li_lsn == INODE_ITEM(blip)->ili_flush_lsn)
> mlip_changed |= xfs_ail_delete_one(ailp, blip);
> @@ -801,15 +785,14 @@ xfs_iflush_done(
> * ili_last_fields bits now that we know that the data corresponding to
> * them is safely on disk.
> */
> - for (blip = lip; blip; blip = next) {
> - next = blip->li_bio_list;
> - blip->li_bio_list = NULL;
> -
> + 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);
> }
> + list_del(&tmp);
> }
>
> /*
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index 861c84e1f674..1b5082aeb538 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -1047,6 +1047,7 @@ xfs_log_item_init(
>
> INIT_LIST_HEAD(&item->li_ail);
> INIT_LIST_HEAD(&item->li_cil);
> + INIT_LIST_HEAD(&item->li_bio_list);
> }
>
> /*
> diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
> index 571fe499a48f..950cb9b4e36e 100644
> --- a/fs/xfs/xfs_trans.h
> +++ b/fs/xfs/xfs_trans.h
> @@ -50,7 +50,7 @@ typedef struct xfs_log_item {
> uint li_type; /* item type */
> uint li_flags; /* misc flags */
> struct xfs_buf *li_buf; /* real buffer pointer */
> - struct xfs_log_item *li_bio_list; /* buffer item list */
> + struct list_head li_bio_list; /* buffer item list */
> void (*li_cb)(struct xfs_buf *,
> struct xfs_log_item *);
> /* buffer item iodone */
>
--
To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
