From: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>
Date: Tue, 15 Dec 2015 15:41:31 +0000 (+0400)
Subject: fcntl: allow to set O_DIRECT flag on pipe
X-Git-Tag: v4.14-rc1~4052^2~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0dbf5f20652108106cb822ad7662c786baaa03ff;p=platform%2Fkernel%2Flinux-rpi.git

fcntl: allow to set O_DIRECT flag on pipe

With packetized mode for pipes, it's not possible to set O_DIRECT on pipe file
via sys_fcntl, because of unsupported sanity checks.
Ability to set this flag will be used by CRIU to migrate packetized pipes.

v2:
Fixed typos and mode variable to check.

Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/fcntl.c b/fs/fcntl.c
index ee85cd4..350a2c8 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -51,7 +51,8 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 	       if (arg & O_NDELAY)
 		   arg |= O_NONBLOCK;
 
-	if (arg & O_DIRECT) {
+	/* Pipe packetized mode is controlled by O_DIRECT flag */
+	if (!S_ISFIFO(filp->f_inode->i_mode) && (arg & O_DIRECT)) {
 		if (!filp->f_mapping || !filp->f_mapping->a_ops ||
 			!filp->f_mapping->a_ops->direct_IO)
 				return -EINVAL;