From 2d095c97e7d08ff279e1978eb70b334075307edf Mon Sep 17 00:00:00 2001
From: Brian Foster <bfoster@redhat.com>
Date: Sun, 17 Sep 2017 14:06:20 -0700
Subject: [PATCH] xfs: ordered buffer log items are never formatted
References: bsc#1085535
Patch-mainline: v4.14-rc1
Git-commit: e9385cc6fb7edf23702de33a2dc82965d92d9392
Stable-commit: 2d095c97e7d08ff279e1978eb70b334075307edf

commit e9385cc6fb7edf23702de33a2dc82965d92d9392 upstream.

Ordered buffers pass through the logging infrastructure without ever
being written to the log. The way this works is that the ordered
buffer status is transferred to the log vector at commit time via
the ->iop_size() callback. In xlog_cil_insert_format_items(),
ordered log vectors bypass ->iop_format() processing altogether.

Therefore it is unnecessary for xfs_buf_item_format() to handle
ordered buffers. Remove the unnecessary logic and assert that an
ordered buffer never reaches this point.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
---
 fs/xfs/xfs_buf_item.c | 12 ++----------
 fs/xfs/xfs_trace.h    |  1 -
 2 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index ff076d11804a..ef2c1375f092 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -323,6 +323,8 @@ xfs_buf_item_format(
 	ASSERT((bip->bli_flags & XFS_BLI_STALE) ||
 	       (xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF
 	        && xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF));
+	ASSERT(!(bip->bli_flags & XFS_BLI_ORDERED) ||
+	       (bip->bli_flags & XFS_BLI_STALE));
 
 
 	/*
@@ -347,16 +349,6 @@ xfs_buf_item_format(
 		bip->bli_flags &= ~XFS_BLI_INODE_BUF;
 	}
 
-	if ((bip->bli_flags & (XFS_BLI_ORDERED|XFS_BLI_STALE)) ==
-							XFS_BLI_ORDERED) {
-		/*
-		 * The buffer has been logged just to order it.  It is not being
-		 * included in the transaction commit, so don't format it.
-		 */
-		trace_xfs_buf_item_format_ordered(bip);
-		return;
-	}
-
 	for (i = 0; i < bip->bli_format_count; i++) {
 		xfs_buf_item_format_segment(bip, lv, &vecp, offset,
 					    &bip->bli_formats[i]);
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index bcc3cdf8e1c5..bb0099708827 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -517,7 +517,6 @@ DEFINE_BUF_ITEM_EVENT(xfs_buf_item_size);
 DEFINE_BUF_ITEM_EVENT(xfs_buf_item_size_ordered);
 DEFINE_BUF_ITEM_EVENT(xfs_buf_item_size_stale);
 DEFINE_BUF_ITEM_EVENT(xfs_buf_item_format);
-DEFINE_BUF_ITEM_EVENT(xfs_buf_item_format_ordered);
 DEFINE_BUF_ITEM_EVENT(xfs_buf_item_format_stale);
 DEFINE_BUF_ITEM_EVENT(xfs_buf_item_ordered);
 DEFINE_BUF_ITEM_EVENT(xfs_buf_item_pin);
-- 
2.16.2