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
next 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
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