diff options
Diffstat (limited to 'fs/xfs/xfs_trans_ail.c')
-rw-r--r-- | fs/xfs/xfs_trans_ail.c | 109 |
1 files changed, 107 insertions, 2 deletions
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 645928c..fe991a7 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -29,6 +29,7 @@ #include "xfs_error.h" STATIC void xfs_ail_insert(struct xfs_ail *, xfs_log_item_t *); +STATIC void xfs_ail_splice(struct xfs_ail *, struct list_head *, xfs_lsn_t); STATIC void xfs_ail_delete(struct xfs_ail *, xfs_log_item_t *); STATIC xfs_log_item_t * xfs_ail_min(struct xfs_ail *); STATIC xfs_log_item_t * xfs_ail_next(struct xfs_ail *, xfs_log_item_t *); @@ -502,6 +503,79 @@ xfs_trans_ail_update( } /* xfs_trans_update_ail */ /* + * xfs_trans_ail_update - bulk AIL insertion operation. + * + * @xfs_trans_ail_update takes an array of log items that all need to be + * positioned at the same LSN in the AIL. If an item is not in the AIL, it will + * be added. Otherwise, it will be repositioned by removing it and re-adding + * it to the AIL. If we move the first item in the AIL, update the log tail to + * match the new minimum LSN in the AIL. + * + * This function takes the AIL lock once to execute the update operations on + * all the items in the array, and as such should not be called with the AIL + * lock held. As a result, once we have the AIL lock, we need to check each log + * item LSN to confirm it needs to be moved forward in the AIL. + * + * To optimise the insert operation, we delete all the items from the AIL in + * the first pass, moving them into a temporary list, then splice the temporary + * list into the correct position in the AIL. This avoids needing to do an + * insert operation on every item. + * + * This function must be called with the AIL lock held. The lock is dropped + * before returning. + */ +void +xfs_trans_ail_update_bulk( + struct xfs_ail *ailp, + struct xfs_log_item **log_items, + int nr_items, + xfs_lsn_t lsn) __releases(ailp->xa_lock) +{ + xfs_log_item_t *mlip; + xfs_lsn_t tail_lsn; + int mlip_changed = 0; + int i; + LIST_HEAD(tmp); + + mlip = xfs_ail_min(ailp); + + for (i = 0; i < nr_items; i++) { + struct xfs_log_item *lip = log_items[i]; + if (lip->li_flags & XFS_LI_IN_AIL) { + /* check if we really need to move the item */ + if (XFS_LSN_CMP(lsn, lip->li_lsn) <= 0) + continue; + + xfs_ail_delete(ailp, lip); + if (mlip == lip) + mlip_changed = 1; + } else { + lip->li_flags |= XFS_LI_IN_AIL; + } + lip->li_lsn = lsn; + list_add(&lip->li_ail, &tmp); + } + + xfs_ail_splice(ailp, &tmp, lsn); + + if (!mlip_changed) { + spin_unlock(&ailp->xa_lock); + return; + } + + /* + * It is not safe to access mlip after the AIL lock is dropped, so we + * must get a copy of li_lsn before we do so. This is especially + * important on 32-bit platforms where accessing and updating 64-bit + * values like li_lsn is not atomic. + */ + mlip = xfs_ail_min(ailp); + tail_lsn = mlip->li_lsn; + spin_unlock(&ailp->xa_lock); + xfs_log_move_tail(ailp->xa_mount, tail_lsn); +} + +/* * Delete the given item from the AIL. It must already be in * the AIL. * @@ -642,8 +716,8 @@ xfs_ail_insert( break; } - ASSERT((&next_lip->li_ail == &ailp->xa_ail) || - (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0)); + ASSERT(&next_lip->li_ail == &ailp->xa_ail || + XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0); list_add(&lip->li_ail, &next_lip->li_ail); @@ -652,6 +726,37 @@ xfs_ail_insert( } /* + * splice the log item list into the AIL at the given LSN. + */ +STATIC void +xfs_ail_splice( + struct xfs_ail *ailp, + struct list_head *list, + xfs_lsn_t lsn) +{ + xfs_log_item_t *next_lip; + + /* + * If the list is empty, just insert the item. + */ + if (list_empty(&ailp->xa_ail)) { + list_splice(list, &ailp->xa_ail); + return; + } + + list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) { + if (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0) + break; + } + + ASSERT((&next_lip->li_ail == &ailp->xa_ail) || + (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0)); + + list_splice_init(list, &next_lip->li_ail); + return; +} + +/* * Delete the given item from the AIL. Return a pointer to the item. */ STATIC void |