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author | Mauricio Faria de Oliveira <mfo@canonical.com> | 2021-02-22 18:41:23 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-19 10:44:55 +0300 |
commit | fd6625a1ec40f8c3bd56805cfab56ea461585293 (patch) | |
tree | f71014733be6f33ec1c8a5e76f8fe393493dd920 /drivers/block | |
parent | 88f0bc830c52f7c6015ea5b174997466ea208c3e (diff) | |
download | linux-fd6625a1ec40f8c3bd56805cfab56ea461585293.tar.xz |
loop: fix I/O error on fsync() in detached loop devices
commit 4ceddce55eb35d15b0f87f5dcf6f0058fd15d3a4 upstream.
There's an I/O error on fsync() in a detached loop device
if it has been previously attached.
The issue is write cache is enabled in the attach path in
loop_configure() but it isn't disabled in the detach path;
thus it remains enabled in the block device regardless of
whether it is attached or not.
Now fsync() can get an I/O request that will just be failed
later in loop_queue_rq() as device's state is not 'Lo_bound'.
So, disable write cache in the detach path.
Do so based on the queue flag, not the loop device flag for
read-only (used to enable) as the queue flag can be changed
via sysfs even on read-only loop devices (e.g., losetup -r.)
Test-case:
# DEV=/dev/loop7
# IMG=/tmp/image
# truncate --size 1M $IMG
# losetup $DEV $IMG
# losetup -d $DEV
Before:
# strace -e fsync parted -s $DEV print 2>&1 | grep fsync
fsync(3) = -1 EIO (Input/output error)
Warning: Error fsyncing/closing /dev/loop7: Input/output error
[ 982.529929] blk_update_request: I/O error, dev loop7, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0
After:
# strace -e fsync parted -s $DEV print 2>&1 | grep fsync
fsync(3) = 0
Co-developed-by: Eric Desrochers <eric.desrochers@canonical.com>
Signed-off-by: Eric Desrochers <eric.desrochers@canonical.com>
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Tested-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/loop.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 06d44ae9701f..f0fa0c8e7ec6 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1224,6 +1224,9 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) goto out_unlock; } + if (test_bit(QUEUE_FLAG_WC, &lo->lo_queue->queue_flags)) + blk_queue_write_cache(lo->lo_queue, false, false); + /* freeze request queue during the transition */ blk_mq_freeze_queue(lo->lo_queue); |