linux-block.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kristian Klausen <kristian@klausen.dk>
To: linux-block@vger.kernel.org
Cc: Kristian Klausen <kristian@klausen.dk>,
	stable@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
	Martijn Coenen <maco@android.com>,
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v2] loop: Fix missing discard support when using LOOP_CONFIGURE
Date: Fri, 18 Jun 2021 13:51:57 +0200	[thread overview]
Message-ID: <20210618115157.31452-1-kristian@klausen.dk> (raw)

Without calling loop_config_discard() the discard flag and parameters
aren't set/updated for the loop device and worst-case they could
indicate discard support when it isn't the case (ex: if the
LOOP_SET_STATUS ioctl was used with a different file prior to
LOOP_CONFIGURE).

Cc: <stable@vger.kernel.org> # 5.8.x-
Fixes: 3448914e8cc5 ("loop: Add LOOP_CONFIGURE ioctl")
Signed-off-by: Kristian Klausen <kristian@klausen.dk>
---
v1 of the patch was tested like so (without the patch):
losetup 2.37<= uses LOOP_CONFIGURE instead of LOOP_SET_STATUS64[1]

# fallocate -l100M disk.img
# rmmod loop
# losetup --version
losetup from util-linux 2.36.2
# losetup --find --show disk.img
/dev/loop0
# grep '' /sys/devices/virtual/block/loop0/queue/*discard*
/sys/devices/virtual/block/loop0/queue/discard_granularity:4096
/sys/devices/virtual/block/loop0/queue/discard_max_bytes:4294966784
/sys/devices/virtual/block/loop0/queue/discard_max_hw_bytes:4294966784
/sys/devices/virtual/block/loop0/queue/discard_zeroes_data:0
/sys/devices/virtual/block/loop0/queue/max_discard_segments:1
# losetup -d /dev/loop0
# [update util-linux]
# losetup --version
losetup from util-linux 2.37
# rmmod loop
# losetup --find --show disk.img
/dev/loop0
# grep '' /sys/devices/virtual/block/loop0/queue/*discard*
/sys/devices/virtual/block/loop0/queue/discard_granularity:0
/sys/devices/virtual/block/loop0/queue/discard_max_bytes:0
/sys/devices/virtual/block/loop0/queue/discard_max_hw_bytes:0
/sys/devices/virtual/block/loop0/queue/discard_zeroes_data:0
/sys/devices/virtual/block/loop0/queue/max_discard_segments:1


With the patch applied:

# losetup --version
losetup from util-linux 2.37
# rmmod loop
# losetup --find --show disk.img
/dev/loop0
# grep '' /sys/devices/virtual/block/loop0/queue/*discard*
/sys/devices/virtual/block/loop0/queue/discard_granularity:4096
/sys/devices/virtual/block/loop0/queue/discard_max_bytes:4294966784
/sys/devices/virtual/block/loop0/queue/discard_max_hw_bytes:4294966784
/sys/devices/virtual/block/loop0/queue/discard_zeroes_data:0
/sys/devices/virtual/block/loop0/queue/max_discard_segments:1

[1] https://github.com/karelzak/util-linux/pull/1152

v2:
Add commit message
Move loop_config_discard() before loop_update_rotational()

 drivers/block/loop.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 76e12f3482a9..8271df125153 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1154,6 +1154,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	blk_queue_physical_block_size(lo->lo_queue, bsize);
 	blk_queue_io_min(lo->lo_queue, bsize);
 
+	loop_config_discard(lo);
 	loop_update_rotational(lo);
 	loop_update_dio(lo);
 	loop_sysfs_init(lo);

base-commit: 70585216fe7730d9fb5453d3e2804e149d0fe201
-- 
2.32.0


             reply	other threads:[~2021-06-18 11:52 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-18 11:51 Kristian Klausen [this message]
2021-06-18 14:52 ` [PATCH v2] loop: Fix missing discard support when using LOOP_CONFIGURE Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210618115157.31452-1-kristian@klausen.dk \
    --to=kristian@klausen.dk \
    --cc=axboe@kernel.dk \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maco@android.com \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).