1 files changed, 154 insertions, 154 deletions

diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index ba47bf65b772..895f61b2b4f0 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -439,6 +439,7 @@ xfs_inode_item_pin(
 	struct xfs_inode	*ip = INODE_ITEM(lip)->ili_inode;
 
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+	ASSERT(lip->li_buf);
 
 	trace_xfs_inode_pin(ip, _RET_IP_);
 	atomic_inc(&ip->i_pincount);
@@ -450,6 +451,12 @@ xfs_inode_item_pin(
  * item which was previously pinned with a call to xfs_inode_item_pin().
  *
  * Also wake up anyone in xfs_iunpin_wait() if the count goes to 0.
+ *
+ * Note that unpin can race with inode cluster buffer freeing marking the buffer
+ * stale. In that case, flush completions are run from the buffer unpin call,
+ * which may happen before the inode is unpinned. If we lose the race, there
+ * will be no buffer attached to the log item, but the inode will be marked
+ * XFS_ISTALE.
  */
 STATIC void
 xfs_inode_item_unpin(
@@ -459,28 +466,12 @@ xfs_inode_item_unpin(
 	struct xfs_inode	*ip = INODE_ITEM(lip)->ili_inode;
 
 	trace_xfs_inode_unpin(ip, _RET_IP_);
+	ASSERT(lip->li_buf || xfs_iflags_test(ip, XFS_ISTALE));
 	ASSERT(atomic_read(&ip->i_pincount) > 0);
 	if (atomic_dec_and_test(&ip->i_pincount))
 		wake_up_bit(&ip->i_flags, __XFS_IPINNED_BIT);
 }
 
-/*
- * Callback used to mark a buffer with XFS_LI_FAILED when items in the buffer
- * have been failed during writeback
- *
- * This informs the AIL that the inode is already flush locked on the next push,
- * and acquires a hold on the buffer to ensure that it isn't reclaimed before
- * dirty data makes it to disk.
- */
-STATIC void
-xfs_inode_item_error(
-	struct xfs_log_item	*lip,
-	struct xfs_buf		*bp)
-{
-	ASSERT(xfs_isiflocked(INODE_ITEM(lip)->ili_inode));
-	xfs_set_li_failed(lip, bp);
-}
-
 STATIC uint
 xfs_inode_item_push(
 	struct xfs_log_item	*lip,
@@ -494,55 +485,44 @@ xfs_inode_item_push(
 	uint			rval = XFS_ITEM_SUCCESS;
 	int			error;
 
-	if (xfs_ipincount(ip) > 0)
+	ASSERT(iip->ili_item.li_buf);
+
+	if (xfs_ipincount(ip) > 0 || xfs_buf_ispinned(bp) ||
+	    (ip->i_flags & XFS_ISTALE))
 		return XFS_ITEM_PINNED;
 
-	if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED))
-		return XFS_ITEM_LOCKED;
+	/* If the inode is already flush locked, we're already flushing. */
+	if (xfs_isiflocked(ip))
+		return XFS_ITEM_FLUSHING;
 
-	/*
-	 * Re-check the pincount now that we stabilized the value by
-	 * taking the ilock.
-	 */
-	if (xfs_ipincount(ip) > 0) {
-		rval = XFS_ITEM_PINNED;
-		goto out_unlock;
-	}
+	if (!xfs_buf_trylock(bp))
+		return XFS_ITEM_LOCKED;
 
-	/*
-	 * Stale inode items should force out the iclog.
-	 */
-	if (ip->i_flags & XFS_ISTALE) {
-		rval = XFS_ITEM_PINNED;
-		goto out_unlock;
-	}
+	spin_unlock(&lip->li_ailp->ail_lock);
 
 	/*
-	 * Someone else is already flushing the inode.  Nothing we can do
-	 * here but wait for the flush to finish and remove the item from
-	 * the AIL.
+	 * We need to hold a reference for flushing the cluster buffer as it may
+	 * fail the buffer without IO submission. In which case, we better get a
+	 * reference for that completion because otherwise we don't get a
+	 * reference for IO until we queue the buffer for delwri submission.
 	 */
-	if (!xfs_iflock_nowait(ip)) {
-		rval = XFS_ITEM_FLUSHING;
-		goto out_unlock;
-	}
-
-	ASSERT(iip->ili_fields != 0 || XFS_FORCED_SHUTDOWN(ip->i_mount));
-	ASSERT(iip->ili_logged == 0 || XFS_FORCED_SHUTDOWN(ip->i_mount));
-
-	spin_unlock(&lip->li_ailp->ail_lock);
-
-	error = xfs_iflush(ip, &bp);
+	xfs_buf_hold(bp);
+	error = xfs_iflush_cluster(bp);
 	if (!error) {
 		if (!xfs_buf_delwri_queue(bp, buffer_list))
 			rval = XFS_ITEM_FLUSHING;
 		xfs_buf_relse(bp);
-	} else if (error == -EAGAIN)
+	} else {
+		/*
+		 * Release the buffer if we were unable to flush anything. On
+		 * any other error, the buffer has already been released.
+		 */
+		if (error == -EAGAIN)
+			xfs_buf_relse(bp);
 		rval = XFS_ITEM_LOCKED;
+	}
 
 	spin_lock(&lip->li_ailp->ail_lock);
-out_unlock:
-	xfs_iunlock(ip, XFS_ILOCK_SHARED);
 	return rval;
 }
 
@@ -621,7 +601,6 @@ static const struct xfs_item_ops xfs_inode_item_ops = {
 	.iop_committed	= xfs_inode_item_committed,
 	.iop_push	= xfs_inode_item_push,
 	.iop_committing	= xfs_inode_item_committing,
-	.iop_error	= xfs_inode_item_error
 };
 
 
@@ -636,9 +615,11 @@ xfs_inode_item_init(
 	struct xfs_inode_log_item *iip;
 
 	ASSERT(ip->i_itemp == NULL);
-	iip = ip->i_itemp = kmem_zone_zalloc(xfs_ili_zone, 0);
+	iip = ip->i_itemp = kmem_cache_zalloc(xfs_ili_zone,
+					      GFP_KERNEL | __GFP_NOFAIL);
 
 	iip->ili_inode = ip;
+	spin_lock_init(&iip->ili_lock);
 	xfs_log_item_init(mp, &iip->ili_item, XFS_LI_INODE,
 						&xfs_inode_item_ops);
 }
@@ -648,110 +629,129 @@ xfs_inode_item_init(
  */
 void
 xfs_inode_item_destroy(
-	xfs_inode_t	*ip)
+	struct xfs_inode	*ip)
 {
-	kmem_free(ip->i_itemp->ili_item.li_lv_shadow);
-	kmem_cache_free(xfs_ili_zone, ip->i_itemp);
+	struct xfs_inode_log_item *iip = ip->i_itemp;
+
+	ASSERT(iip->ili_item.li_buf == NULL);
+
+	ip->i_itemp = NULL;
+	kmem_free(iip->ili_item.li_lv_shadow);
+	kmem_cache_free(xfs_ili_zone, iip);
 }
 
 
 /*
- * This is the inode flushing I/O completion routine.  It is called
- * from interrupt level when the buffer containing the inode is
- * 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.
+ * We only want to pull the item from the AIL if it is actually there
+ * and its location in the log has not changed since we started the
+ * flush.  Thus, we only bother if the inode's lsn has not changed.
  */
-void
-xfs_iflush_done(
-	struct xfs_buf		*bp,
-	struct xfs_log_item	*lip)
+static void
+xfs_iflush_ail_updates(
+	struct xfs_ail		*ailp,
+	struct list_head	*list)
 {
-	struct xfs_inode_log_item *iip;
-	struct xfs_log_item	*blip, *n;
-	struct xfs_ail		*ailp = lip->li_ailp;
-	int			need_ail = 0;
-	LIST_HEAD(tmp);
+	struct xfs_log_item	*lip;
+	xfs_lsn_t		tail_lsn = 0;
 
-	/*
-	 * Scan the buffer IO completions for other inodes being completed and
-	 * attach them to the current inode log item.
-	 */
+	/* this is an opencoded batch version of xfs_trans_ail_delete */
+	spin_lock(&ailp->ail_lock);
+	list_for_each_entry(lip, list, li_bio_list) {
+		xfs_lsn_t	lsn;
 
-	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)
+		clear_bit(XFS_LI_FAILED, &lip->li_flags);
+		if (INODE_ITEM(lip)->ili_flush_lsn != lip->li_lsn)
 			continue;
 
-		list_move_tail(&blip->li_bio_list, &tmp);
+		lsn = xfs_ail_delete_one(ailp, lip);
+		if (!tail_lsn && lsn)
+			tail_lsn = lsn;
+	}
+	xfs_ail_update_finish(ailp, tail_lsn);
+}
+
+/*
+ * Walk the list of inodes that have completed their IOs. If they are clean
+ * remove them from the list and dissociate them from the buffer. Buffers that
+ * are still dirty remain linked to the buffer and on the list. Caller must
+ * handle them appropriately.
+ */
+static void
+xfs_iflush_finish(
+	struct xfs_buf		*bp,
+	struct list_head	*list)
+{
+	struct xfs_log_item	*lip, *n;
+
+	list_for_each_entry_safe(lip, n, list, li_bio_list) {
+		struct xfs_inode_log_item *iip = INODE_ITEM(lip);
+		bool	drop_buffer = false;
+
+		spin_lock(&iip->ili_lock);
+
 		/*
-		 * while we have the item, do the unlocked check for needing
-		 * the AIL lock.
+		 * Remove the reference to the cluster buffer if the inode is
+		 * clean in memory and drop the buffer reference once we've
+		 * dropped the locks we hold.
 		 */
-		iip = INODE_ITEM(blip);
-		if ((iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) ||
-		    test_bit(XFS_LI_FAILED, &blip->li_flags))
-			need_ail++;
+		ASSERT(iip->ili_item.li_buf == bp);
+		if (!iip->ili_fields) {
+			iip->ili_item.li_buf = NULL;
+			list_del_init(&lip->li_bio_list);
+			drop_buffer = true;
+		}
+		iip->ili_last_fields = 0;
+		iip->ili_flush_lsn = 0;
+		spin_unlock(&iip->ili_lock);
+		xfs_ifunlock(iip->ili_inode);
+		if (drop_buffer)
+			xfs_buf_rele(bp);
 	}
+}
 
-	/* 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) ||
-	    test_bit(XFS_LI_FAILED, &lip->li_flags))
-		need_ail++;
+/*
+ * Inode buffer IO completion routine.  It is responsible for removing inodes
+ * attached to the buffer from the AIL if they have not been re-logged, as well
+ * as completing the flush and unlocking the inode.
+ */
+void
+xfs_iflush_done(
+	struct xfs_buf		*bp)
+{
+	struct xfs_log_item	*lip, *n;
+	LIST_HEAD(flushed_inodes);
+	LIST_HEAD(ail_updates);
 
 	/*
-	 * We only want to pull the item from the AIL if it is
-	 * actually there and its location in the log has not
-	 * changed since we started the flush.  Thus, we only bother
-	 * if the ili_logged flag is set and the inode's lsn has not
-	 * changed.  First we check the lsn outside
-	 * the lock since it's cheaper, and then we recheck while
-	 * holding the lock before removing the inode from the AIL.
+	 * Pull the attached inodes from the buffer one at a time and take the
+	 * appropriate action on them.
 	 */
-	if (need_ail) {
-		xfs_lsn_t	tail_lsn = 0;
-
-		/* 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 (INODE_ITEM(blip)->ili_logged &&
-			    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);
-				if (!tail_lsn && lsn)
-					tail_lsn = lsn;
-			} else {
-				xfs_clear_li_failed(blip);
-			}
+	list_for_each_entry_safe(lip, n, &bp->b_li_list, li_bio_list) {
+		struct xfs_inode_log_item *iip = INODE_ITEM(lip);
+
+		if (xfs_iflags_test(iip->ili_inode, XFS_ISTALE)) {
+			xfs_iflush_abort(iip->ili_inode);
+			continue;
 		}
-		xfs_ail_update_finish(ailp, tail_lsn);
+		if (!iip->ili_last_fields)
+			continue;
+
+		/* Do an unlocked check for needing the AIL lock. */
+		if (iip->ili_flush_lsn == lip->li_lsn ||
+		    test_bit(XFS_LI_FAILED, &lip->li_flags))
+			list_move_tail(&lip->li_bio_list, &ail_updates);
+		else
+			list_move_tail(&lip->li_bio_list, &flushed_inodes);
 	}
 
-	/*
-	 * 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.
-	 */
-	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);
+	if (!list_empty(&ail_updates)) {
+		xfs_iflush_ail_updates(bp->b_mount->m_ail, &ail_updates);
+		list_splice_tail(&ail_updates, &flushed_inodes);
 	}
-	list_del(&tmp);
+
+	xfs_iflush_finish(bp, &flushed_inodes);
+	if (!list_empty(&flushed_inodes))
+		list_splice_tail(&flushed_inodes, &bp->b_li_list);
 }
 
 /*
@@ -762,37 +762,37 @@ xfs_iflush_done(
  */
 void
 xfs_iflush_abort(
-	struct xfs_inode		*ip)
+	struct xfs_inode	*ip)
 {
-	struct xfs_inode_log_item	*iip = ip->i_itemp;
+	struct xfs_inode_log_item *iip = ip->i_itemp;
+	struct xfs_buf		*bp = NULL;
 
 	if (iip) {
-		xfs_trans_ail_delete(&iip->ili_item, 0);
-		iip->ili_logged = 0;
 		/*
-		 * Clear the ili_last_fields bits now that we know that the
-		 * data corresponding to them is safely on disk.
+		 * Clear the failed bit before removing the item from the AIL so
+		 * xfs_trans_ail_delete() doesn't try to clear and release the
+		 * buffer attached to the log item before we are done with it.
 		 */
-		iip->ili_last_fields = 0;
+		clear_bit(XFS_LI_FAILED, &iip->ili_item.li_flags);
+		xfs_trans_ail_delete(&iip->ili_item, 0);
+
 		/*
 		 * Clear the inode logging fields so no more flushes are
 		 * attempted.
 		 */
+		spin_lock(&iip->ili_lock);
+		iip->ili_last_fields = 0;
 		iip->ili_fields = 0;
 		iip->ili_fsync_fields = 0;
+		iip->ili_flush_lsn = 0;
+		bp = iip->ili_item.li_buf;
+		iip->ili_item.li_buf = NULL;
+		list_del_init(&iip->ili_item.li_bio_list);
+		spin_unlock(&iip->ili_lock);
 	}
-	/*
-	 * Release the inode's flush lock since we're done with it.
-	 */
 	xfs_ifunlock(ip);
-}
-
-void
-xfs_istale_done(
-	struct xfs_buf		*bp,
-	struct xfs_log_item	*lip)
-{
-	xfs_iflush_abort(INODE_ITEM(lip)->ili_inode);
+	if (bp)
+		xfs_buf_rele(bp);
 }
 
 /*