xfs: update and factor xfs_trans_committed()

The function header to xfs-trans_committed has long had this
comment:

 * THIS SHOULD BE REWRITTEN TO USE xfs_trans_next_item()

To prepare for different methods of committing items, convert the
code to use xfs_trans_next_item() and factor the code into smaller,
more digestible chunks.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 95 insertions, 129 deletions

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 2bff22995127..084bd3a13184 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -49,7 +49,6 @@
 STATIC void     xfs_trans_apply_sb_deltas(xfs_trans_t *);
 STATIC void     xfs_trans_uncommit(xfs_trans_t *, uint);
 STATIC void     xfs_trans_committed(xfs_trans_t *, int);
-STATIC void     xfs_trans_chunk_committed(xfs_log_item_chunk_t *, xfs_lsn_t, int);
 STATIC void     xfs_trans_free(xfs_trans_t *);
 
 kmem_zone_t     *xfs_trans_zone;
@@ -1301,60 +1300,86 @@ xfs_trans_roll(
 }
 
 /*
- * THIS SHOULD BE REWRITTEN TO USE xfs_trans_next_item().
+ * The committed item processing consists of calling the committed routine of
+ * each logged item, updating the item's position in the AIL if necessary, and
+ * unpinning each item.  If the committed routine returns -1, then do nothing
+ * further with the item because it may have been freed.
  *
- * This is typically called by the LM when a transaction has been fully
- * committed to disk.  It needs to unpin the items which have
- * been logged by the transaction and update their positions
- * in the AIL if necessary.
- * This also gets called when the transactions didn't get written out
- * because of an I/O error. Abortflag & XFS_LI_ABORTED is set then.
+ * Since items are unlocked when they are copied to the incore log, it is
+ * possible for two transactions to be completing and manipulating the same
+ * item simultaneously.  The AIL lock will protect the lsn field of each item.
+ * The value of this field can never go backwards.
  *
- * Call xfs_trans_chunk_committed() to process the items in
- * each chunk.
+ * We unpin the items after repositioning them in the AIL, because otherwise
+ * they could be immediately flushed and we'd have to race with the flusher
+ * trying to pull the item from the AIL as we add it.
  */
-STATIC void
-xfs_trans_committed(
-        xfs_trans_t     *tp,
-        int             abortflag)
+static void
+xfs_trans_item_committed(
+        xfs_log_item_t  *lip,
+        xfs_lsn_t       commit_lsn,
+        int             aborted)
 {
-        xfs_log_item_chunk_t    *licp;
-        xfs_log_item_chunk_t    *next_licp;
-        xfs_log_busy_chunk_t    *lbcp;
-        xfs_log_busy_slot_t     *lbsp;
-        int                     i;
+        xfs_lsn_t       item_lsn;
+        struct xfs_ail  *ailp;
+
+        if (aborted)
+                lip->li_flags |= XFS_LI_ABORTED;
 
         /*
-         * Call the transaction's completion callback if there
-         * is one.
+         * Send in the ABORTED flag to the COMMITTED routine so that it knows
+         * whether the transaction was aborted or not.
          */
-        if (tp->t_callback != NULL) {
-                tp->t_callback(tp, tp->t_callarg);
-        }
+        item_lsn = IOP_COMMITTED(lip, commit_lsn);
 
         /*
-         * Special case the chunk embedded in the transaction.
+         * If the committed routine returns -1, item has been freed.
          */
-        licp = &(tp->t_items);
-        if (!(xfs_lic_are_all_free(licp))) {
-                xfs_trans_chunk_committed(licp, tp->t_lsn, abortflag);
-        }
+        if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0)
+                return;
 
         /*
-         * Process the items in each chunk in turn.
+         * If the returned lsn is greater than what it contained before, update
+         * the location of the item in the AIL.  If it is not, then do nothing.
+         * Items can never move backwards in the AIL.
+         *
+         * While the new lsn should usually be greater, it is possible that a
+         * later transaction completing simultaneously with an earlier one
+         * using the same item could complete first with a higher lsn.  This
+         * would cause the earlier transaction to fail the test below.
          */
-        licp = licp->lic_next;
-        while (licp != NULL) {
-                ASSERT(!xfs_lic_are_all_free(licp));
-                xfs_trans_chunk_committed(licp, tp->t_lsn, abortflag);
-                next_licp = licp->lic_next;
-                kmem_free(licp);
-                licp = next_licp;
+        ailp = lip->li_ailp;
+        spin_lock(&ailp->xa_lock);
+        if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0) {
+                /*
+                 * This will set the item's lsn to item_lsn and update the
+                 * position of the item in the AIL.
+                 *
+                 * xfs_trans_ail_update() drops the AIL lock.
+                 */
+                xfs_trans_ail_update(ailp, lip, item_lsn);
+        } else {
+                spin_unlock(&ailp->xa_lock);
         }
 
         /*
-         * Clear all the per-AG busy list items listed in this transaction
+         * Now that we've repositioned the item in the AIL, unpin it so it can
+         * be flushed. Pass information about buffer stale state down from the
+         * log item flags, if anyone else stales the buffer we do not want to
+         * pay any attention to it.
          */
+        IOP_UNPIN(lip);
+}
+
+/* Clear all the per-AG busy list items listed in this transaction */
+static void
+xfs_trans_clear_busy_extents(
+        struct xfs_trans        *tp)
+{
+        xfs_log_busy_chunk_t    *lbcp;
+        xfs_log_busy_slot_t     *lbsp;
+        int                     i;
+
         lbcp = &tp->t_busy;
         while (lbcp != NULL) {
                 for (i = 0, lbsp = lbcp->lbc_busy; i < lbcp->lbc_unused; i++, lbsp++) {
@@ -1366,107 +1391,48 @@ xfs_trans_committed(
                 lbcp = lbcp->lbc_next;
         }
         xfs_trans_free_busy(tp);
-
-        /*
-         * That's it for the transaction structure.  Free it.
-         */
-        xfs_trans_free(tp);
 }
 
 /*
- * This is called to perform the commit processing for each
- * item described by the given chunk.
- *
- * The commit processing consists of unlocking items which were
- * held locked with the SYNC_UNLOCK attribute, calling the committed
- * routine of each logged item, updating the item's position in the AIL
- * if necessary, and unpinning each item.  If the committed routine
- * returns -1, then do nothing further with the item because it
- * may have been freed.
- *
- * Since items are unlocked when they are copied to the incore
- * log, it is possible for two transactions to be completing
- * and manipulating the same item simultaneously.  The AIL lock
- * will protect the lsn field of each item.  The value of this
- * field can never go backwards.
+ * This is typically called by the LM when a transaction has been fully
+ * committed to disk.  It needs to unpin the items which have
+ * been logged by the transaction and update their positions
+ * in the AIL if necessary.
  *
- * We unpin the items after repositioning them in the AIL, because
- * otherwise they could be immediately flushed and we'd have to race
- * with the flusher trying to pull the item from the AIL as we add it.
+ * This also gets called when the transactions didn't get written out
+ * because of an I/O error. Abortflag & XFS_LI_ABORTED is set then.
  */
 STATIC void
-xfs_trans_chunk_committed(
-        xfs_log_item_chunk_t    *licp,
-        xfs_lsn_t               lsn,
-        int                     aborted)
+xfs_trans_committed(
+        xfs_trans_t     *tp,
+        int             abortflag)
 {
         xfs_log_item_desc_t     *lidp;
-        xfs_log_item_t          *lip;
-        xfs_lsn_t               item_lsn;
-        int                     i;
-
-        lidp = licp->lic_descs;
-        for (i = 0; i < licp->lic_unused; i++, lidp++) {
-                struct xfs_ail          *ailp;
-
-                if (xfs_lic_isfree(licp, i)) {
-                        continue;
-                }
-
-                lip = lidp->lid_item;
-                if (aborted)
-                        lip->li_flags |= XFS_LI_ABORTED;
-
-                /*
-                 * Send in the ABORTED flag to the COMMITTED routine
-                 * so that it knows whether the transaction was aborted
-                 * or not.
-                 */
-                item_lsn = IOP_COMMITTED(lip, lsn);
+        xfs_log_item_chunk_t    *licp;
+        xfs_log_item_chunk_t    *next_licp;
 
-                /*
-                 * If the committed routine returns -1, make
-                 * no more references to the item.
-                 */
-                if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0) {
-                        continue;
-                }
+        /*
+         * Call the transaction's completion callback if there
+         * is one.
+         */
+        if (tp->t_callback != NULL) {
+                tp->t_callback(tp, tp->t_callarg);
+        }
 
-                /*
-                 * If the returned lsn is greater than what it
-                 * contained before, update the location of the
-                 * item in the AIL.  If it is not, then do nothing.
-                 * Items can never move backwards in the AIL.
-                 *
-                 * While the new lsn should usually be greater, it
-                 * is possible that a later transaction completing
-                 * simultaneously with an earlier one using the
-                 * same item could complete first with a higher lsn.
-                 * This would cause the earlier transaction to fail
-                 * the test below.
-                 */
-                ailp = lip->li_ailp;
-                spin_lock(&ailp->xa_lock);
-                if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0) {
-                        /*
-                         * This will set the item's lsn to item_lsn
-                         * and update the position of the item in
-                         * the AIL.
-                         *
-                         * xfs_trans_ail_update() drops the AIL lock.
-                         */
-                        xfs_trans_ail_update(ailp, lip, item_lsn);
-                } else {
-                        spin_unlock(&ailp->xa_lock);
-                }
+        for (lidp = xfs_trans_first_item(tp);
+             lidp != NULL;
+             lidp = xfs_trans_next_item(tp, lidp)) {
+                xfs_trans_item_committed(lidp->lid_item, tp->t_lsn, abortflag);
+        }
 
-                /*
-                 * Now that we've repositioned the item in the AIL,
-                 * unpin it so it can be flushed. Pass information
-                 * about buffer stale state down from the log item
-                 * flags, if anyone else stales the buffer we do not
-                 * want to pay any attention to it.
-                 */
-                IOP_UNPIN(lip);
+        /* free the item chunks, ignoring the embedded chunk */
+        licp = tp->t_items.lic_next;
+        while (licp != NULL) {
+                next_licp = licp->lic_next;
+                kmem_free(licp);
+                licp = next_licp;
         }
+
+        xfs_trans_clear_busy_extents(tp);
+        xfs_trans_free(tp);
 }