Re: [PATCH v2] FAT: use schedule_timeout_uninterruptible() instead of congestion_wait()

From: OGAWA Hirofumi
Date: Sat Dec 11 2021 - 03:27:58 EST


"NeilBrown" <neilb@xxxxxxx> writes:

> congestion_wait() in this context is just a sleep - block devices do not
> in general support congestion signalling any more.
>
> The goal here is to wait for any recently written data to get to
> storage. blkdev_issue_flush() is thought to be too expensive, so
> replace congestion_wait() with an explicit timeout.

If just replace, the following looks better

set_current_state(TASK_UNINTERRUPTIBLE);
io_schedule_timeout(HZ/10);

Otherwise,

Acked-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>

> Signed-off-by: NeilBrown <neilb@xxxxxxx>
> ---
> fs/fat/file.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/fat/file.c b/fs/fat/file.c
> index 13855ba49cd9..2321fb3eded5 100644
> --- a/fs/fat/file.c
> +++ b/fs/fat/file.c
> @@ -175,9 +175,9 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, 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);
> + schedule_timeout_uninterruptible(HZ/10);
> }
> return 0;
> }

--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>