1 files changed, 74 insertions, 16 deletions

diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 7c8d30c453c3..fd4f398bd6f1 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -842,15 +842,64 @@ xfs_inode_item_destroy(
  * flushed to disk.  It is responsible for removing the inode item
  * from the AIL if it has not been re-logged, and unlocking the inode's
  * flush lock.
+ *
+ * To reduce AIL lock traffic as much as possible, we scan the buffer log item
+ * list for other inodes that will run this function. We remove them from the
+ * buffer list so we can process all the inode IO completions in one AIL lock
+ * traversal.
  */
 void
 xfs_iflush_done(
         struct xfs_buf          *bp,
         struct xfs_log_item     *lip)
 {
-        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
-        xfs_inode_t             *ip = iip->ili_inode;
+        struct xfs_inode_log_item *iip;
+        struct xfs_log_item     *blip;
+        struct xfs_log_item     *next;
+        struct xfs_log_item     *prev;
         struct xfs_ail          *ailp = lip->li_ailp;
+        int                     need_ail = 0;
+
+        /*
+         * Scan the buffer IO completions for other inodes being completed and
+         * attach them to the current inode log item.
+         */
+        blip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
+        prev = NULL;
+        while (blip != NULL) {
+                if (lip->li_cb != xfs_iflush_done) {
+                        prev = blip;
+                        blip = blip->li_bio_list;
+                        continue;
+                }
+
+                /* remove from list */
+                next = blip->li_bio_list;
+                if (!prev) {
+                        XFS_BUF_SET_FSPRIVATE(bp, next);
+                } else {
+                        prev->li_bio_list = next;
+                }
+
+                /* add to current list */
+                blip->li_bio_list = lip->li_bio_list;
+                lip->li_bio_list = blip;
+
+                /*
+                 * while we have the item, do the unlocked check for needing
+                 * the AIL lock.
+                 */
+                iip = INODE_ITEM(blip);
+                if (iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn)
+                        need_ail++;
+
+                blip = next;
+        }
+
+        /* 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)
+                need_ail++;
 
         /*
          * We only want to pull the item from the AIL if it is
@@ -861,28 +910,37 @@ xfs_iflush_done(
          * the lock since it's cheaper, and then we recheck while
          * holding the lock before removing the inode from the AIL.
          */
-        if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) {
+        if (need_ail) {
+                struct xfs_log_item *log_items[need_ail];
+                int i = 0;
                 spin_lock(&ailp->xa_lock);
-                if (lip->li_lsn == iip->ili_flush_lsn) {
-                        /* xfs_trans_ail_delete() drops the AIL lock. */
-                        xfs_trans_ail_delete(ailp, lip);
-                } else {
-                        spin_unlock(&ailp->xa_lock);
+                for (blip = lip; blip; blip = blip->li_bio_list) {
+                        iip = INODE_ITEM(blip);
+                        if (iip->ili_logged &&
+                            blip->li_lsn == iip->ili_flush_lsn) {
+                                log_items[i++] = blip;
+                        }
+                        ASSERT(i <= need_ail);
                 }
+                /* xfs_trans_ail_delete_bulk() drops the AIL lock. */
+                xfs_trans_ail_delete_bulk(ailp, log_items, i);
         }
 
-        iip->ili_logged = 0;
 
         /*
-         * Clear the ili_last_fields bits now that we know that the
-         * data corresponding to them is safely on disk.
+         * 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.
          */
-        iip->ili_last_fields = 0;
+        for (blip = lip; blip; blip = next) {
+                next = blip->li_bio_list;
+                blip->li_bio_list = NULL;
 
-        /*
-         * Release the inode's flush lock since we're done with it.
-         */
-        xfs_ifunlock(ip);
+                iip = INODE_ITEM(blip);
+                iip->ili_logged = 0;
+                iip->ili_last_fields = 0;
+                xfs_ifunlock(iip->ili_inode);
+        }
 }
 
 /*