From: Wengang Wang <wen.gang.wang@oracle.com>
Date: Tue, 29 Jan 2019 03:21:20 +0000 (-0800)
Subject: Revert "xfs: remove nonblocking mode from xfs_vm_writepage"
X-Git-Tag: v4.1.12-124.31.3~308
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=71886fff42bcb86132f0a9d267be555004523fc7;p=users%2Fjedix%2Flinux-maple.git

Revert "xfs: remove nonblocking mode from xfs_vm_writepage"

This reverts commit 6e2de7d4578d4f6ae76979286de5c5ee8e91754a.

These commits are very possibly to cause SIGBUS issue. (We can't verify
that in customer's environment). Revert them.

Orabug: 29279692

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Shan Hai <shan.hai@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
---

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 75edf5846f32..37e855c1342f 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -287,7 +287,8 @@ xfs_map_blocks(
 	struct inode		*inode,
 	loff_t			offset,
 	struct xfs_bmbt_irec	*imap,
-	int			type)
+	int			type,
+	int			nonblocking)
 {
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
@@ -303,7 +304,12 @@ xfs_map_blocks(
 	if (type == XFS_IO_UNWRITTEN)
 		bmapi_flags |= XFS_BMAPI_IGSTATE;
 
-	xfs_ilock(ip, XFS_ILOCK_SHARED);
+	if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
+		if (nonblocking)
+			return -EAGAIN;
+		xfs_ilock(ip, XFS_ILOCK_SHARED);
+	}
+
 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
 	       (ip->i_df.if_flags & XFS_IFEXTENTS));
 	ASSERT(offset <= mp->m_super->s_maxbytes);
@@ -955,6 +961,7 @@ xfs_vm_writepage(
 	ssize_t			len;
 	int			err, imap_valid = 0, uptodate = 1;
 	int			count = 0;
+	int			nonblocking = 0;
 
 	trace_xfs_writepage(inode, page, 0, 0);
 
@@ -1054,6 +1061,9 @@ xfs_vm_writepage(
 	offset = page_offset(page);
 	type = XFS_IO_OVERWRITE;
 
+	if (wbc->sync_mode == WB_SYNC_NONE)
+		nonblocking = 1;
+
 	do {
 		int new_ioend = 0;
 
@@ -1113,7 +1123,8 @@ xfs_vm_writepage(
 			 * time.
 			 */
 			new_ioend = 1;
-			err = xfs_map_blocks(inode, offset, &imap, type);
+			err = xfs_map_blocks(inode, offset, &imap, type,
+					     nonblocking);
 			if (err)
 				goto error;
 			imap_valid = xfs_imap_valid(inode, &imap, offset);
@@ -1183,6 +1194,9 @@ error:
 	if (iohead)
 		xfs_cancel_ioend(iohead);
 
+	if (err == -EAGAIN)
+		goto redirty;
+
 	xfs_aops_discard_page(page);
 	ClearPageUptodate(page);
 	unlock_page(page);