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From:   "NeilBrown" <neilb@suse.de>
To:     Andrew Morton <akpm@linux-foundation.org>,
        "OGAWA Hirofumi" <hirofumi@mail.parknet.co.jp>
Cc:     linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        "Christoph Hellwig" <hch@infradead.org>
Subject: [PATCH v3] FAT: use io_schedule_timeout() instead of congestion_wait()
In-reply-to: <875yrtql2s.fsf@mail.parknet.co.jp>
References: <163712349419.13692.2859038330142282757@noble.neil.brown.name>,
 <87ee79yiik.fsf@mail.parknet.co.jp>,
 <163754226639.13692.10449616189734943162@noble.neil.brown.name>,
 <874k84hi5q.fsf@mail.parknet.co.jp>,
 <163911011670.9928.6438117555175130033@noble.neil.brown.name>,
 <163911016975.9928.6568675782275129@noble.neil.brown.name>,
 <87h7bfmtqc.fsf@mail.parknet.co.jp>,
 <163936252397.22433.9103044991910658320@noble.neil.brown.name>,
 <875yrtql2s.fsf@mail.parknet.co.jp>
Date:   Mon, 13 Dec 2021 14:17:25 +1100
Message-id: <163936544519.22433.13400436295732112065@noble.neil.brown.name>
Precedence: bulk


congestion_wait() in this context is just a sleep - block devices do not
support congestion signalling any more.

The goal for this wait, which was introduced in Commit ae78bf9c4f5f
("[PATCH] add -o flush for fat") is to wait for any recently written
data to get to storage.  We currently have no direct mechanism to do
this, so a simple wait that behaves identically to the current
congestion_wait() is the best we can do.

This is a step towards removing congestion_wait()

Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NeilBrown <neilb@suse.de>
---

Hi Andrew,
 I believe you are an appropriate conduit for fs/fat patches once that
 have been suitably acked.
Thanks
NeilBrown

 fs/fat/file.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/fat/file.c b/fs/fat/file.c
index 13855ba49cd9..a5a309fcc7fa 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -175,9 +175,10 @@ long fat_generic_ioctl(struct file *filp, unsigned int c=
md, unsigned long arg)
 static int fat_file_release(struct inode *inode, struct file *filp)
 {
 	if ((filp->f_mode & FMODE_WRITE) &&
-	     MSDOS_SB(inode->i_sb)->options.flush) {
+	    MSDOS_SB(inode->i_sb)->options.flush) {
 		fat_flush_inodes(inode->i_sb, inode, NULL);
-		congestion_wait(BLK_RW_ASYNC, HZ/10);
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		io_schedule_timeout(HZ/10);
 	}
 	return 0;
 }
--=20
2.34.1