loop: cleanup and few improvements

PATCH Superseded Chaitanya Kulkarni 3 participants 7 messages Feb 15, 2022 Block layer

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Chaitanya Kulkarni

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2022-02-15 11:51 UTC #0 lore raw

v2 cover loop: cleanup and few improvements

Hi,

This has few improvment and cleanups such as using sysfs_emit() for the sysfs dev attributes and removing variables that are only used once and a cleanup with fixing declaration.

Below is the test log where 10 loop devices created, each device is linked to it's own file in ./loopX, formatted with xfs and mounted on /mnt/loopX. For each device it reads the offset, sizelimit, autoclear, partscan, and dio attr from sysfs using cat command, then it runs fio verify job on it.

In summary write-verify fio job seems to work fine :-
write-and-verify: (groupid=0, jobs=1): err= 0: pid=3495: Mon Feb 14 00:43:19 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=3960: Mon Feb 14 00:45:17 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=4321: Mon Feb 14 00:47:15 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=4369: Mon Feb 14 00:49:20 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=4443: Mon Feb 14 00:51:25 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=4536: Mon Feb 14 00:53:25 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=4770: Mon Feb 14 00:55:24 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=4933: Mon Feb 14 00:57:31 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=5008: Mon Feb 14 00:59:35 2022
write-and-verify: (groupid=0, jobs=1): err= 0: pid=5048: Mon Feb 14 01:01:58 2022

Below is detailed test log.

-ck

changes from V1:-

1. Squash all patches for sysfs_emit() into single patch. (Jens)

Chaitanya Kulkarni (4):
loop: use sysfs_emit() in the sysfs xxx show()
loop: remove extra variable in lo_fallocate()
loop: remove extra variable in lo_req_flush
loop: allow user to set the queue depth

 drivers/block/loop.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

oot@dev linux-block (for-next) # git am p/loop-sysfs-emit/*patch
Patch is empty.
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
root@dev linux-block (for-next) # git am --skip
Applying: loop: use sysfs_emit() in the sysfs xxx show()
Applying: loop: remove extra variable in lo_fallocate()
Applying: loop: remove extra variable in lo_req_flush
Applying: loop: allow user to set the queue depth
root@dev linux-block (for-next) # ./compile_nullb.sh 10
+ umount /mnt/nullb0
umount: /mnt/nullb0: no mount point specified.
+ rmdir 'config/nullb/nullb*'
rmdir: failed to remove 'config/nullb/nullb*': No such file or directory
+ dmesg -c
+ modprobe -r null_blk
+ lsmod
+ grep null_blk
++ nproc
+ make -j 48 M=drivers/block modules
CC [M] drivers/block/loop.o
CC [M] drivers/block/pktcdvd.o
MODPOST drivers/block/Module.symvers
LD [M] drivers/block/loop.ko
LD [M] drivers/block/pktcdvd.ko
+ HOST=drivers/block/null_blk/
++ uname -r
+ HOST_DEST=/lib/modules/5.17.0-rc3blk+/kernel/drivers/block/null_blk/
+ cp drivers/block/null_blk//null_blk.ko /lib/modules/5.17.0-rc3blk+/kernel/drivers/block/null_blk//
+ ls -lrth /lib/modules/5.17.0-rc3blk+/kernel/drivers/block/null_blk//null_blk.ko
-rw-r--r--. 1 root root 1.1M Feb 14 22:12 /lib/modules/5.17.0-rc3blk+/kernel/drivers/block/null_blk//null_blk.ko
+ sleep 1
+ dmesg -c
root@dev linux-block (for-next) # ./compile_loop.sh 10
+ FILE=./loop
+ LOOP_MNT=/mnt/loop
+ NN=10
+ unload_loop
++ shuf -i 1-10 -n 10
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop10
umount: /mnt/loop10: no mount point specified.
+ rm -fr ./loop10
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop4
umount: /mnt/loop4: no mount point specified.
+ rm -fr ./loop4
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop8
+ rm -fr ./loop8
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop2
+ rm -fr ./loop2
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop9
umount: /mnt/loop9: no mount point specified.
+ rm -fr ./loop9
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop1
+ rm -fr ./loop1
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop7
+ rm -fr ./loop7
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop3
+ rm -fr ./loop3
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop6
umount: /mnt/loop6: not mounted.
+ rm -fr ./loop6
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop5
umount: /mnt/loop5: no mount point specified.
+ rm -fr ./loop5
+ losetup -D
+ sleep 3
+ rmmod loop
+ modprobe -r loop
+ lsmod
+ grep loop
++ shuf -i 1-10 -n 10
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop3
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop1
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop8
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop10
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop5
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop9
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop6
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop4
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop2
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop7
+ rm -fr /mnt/loop1 /mnt/loop2 /mnt/loop3 /mnt/loop6 /mnt/loop7 /mnt/loop8
+ compile_loop
++ nproc
+ make -j 48 M=drivers/block modules
+ HOST=drivers/block/
++ uname -r
+ HOST_DEST=/lib/modules/5.17.0-rc3blk+/kernel/drivers/block
+ cp drivers/block//loop.ko /lib/modules/5.17.0-rc3blk+/kernel/drivers/block/
+ load_loop
+ insmod drivers/block/loop.ko max_loop=11 hw_queue_depth=32
++ shuf -i 1-10 -n 10
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop4
+ truncate -s 2048M ./loop4
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop4 ./loop4
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC
/dev/loop4 0 0 0 0 /mnt/data/linux-block/loop4 1 512
+ sleep 1
+ mkfs.xfs -f /dev/loop4

meta-data=/dev/loop4             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop4 /mnt/loop4
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop4/loop/offset : '
cat /sys/block/loop4/loop/offset : + cat /sys/block/loop4/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop4/loop/sizelimit : '
cat /sys/block/loop4/loop/sizelimit : + cat /sys/block/loop4/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop4/loop/autoclear : '
cat /sys/block/loop4/loop/autoclear : + cat /sys/block/loop4/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop4/loop/partscan : '
cat /sys/block/loop4/loop/partscan : + cat /sys/block/loop4/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop4/loop/dio : '
cat /sys/block/loop4/loop/dio : + cat /sys/block/loop4/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop5
+ truncate -s 2048M ./loop5
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop5 ./loop5
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop4         0      0         0  0 /mnt/data/linux-block/loop4   1     512
/dev/loop5         0      0         0  0 /mnt/data/linux-block/loop5   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop5
meta-data=/dev/loop5             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop5 /mnt/loop5
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop5/loop/offset : '
cat /sys/block/loop5/loop/offset : + cat /sys/block/loop5/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop5/loop/sizelimit : '
cat /sys/block/loop5/loop/sizelimit : + cat /sys/block/loop5/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop5/loop/autoclear : '
cat /sys/block/loop5/loop/autoclear : + cat /sys/block/loop5/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop5/loop/partscan : '
cat /sys/block/loop5/loop/partscan : + cat /sys/block/loop5/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop5/loop/dio : '
cat /sys/block/loop5/loop/dio : + cat /sys/block/loop5/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop7
+ truncate -s 2048M ./loop7
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop7 ./loop7
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop4         0      0         0  0 /mnt/data/linux-block/loop4   1     512
/dev/loop7         0      0         0  0 /mnt/data/linux-block/loop7   1     512
/dev/loop5         0      0         0  0 /mnt/data/linux-block/loop5   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop7
meta-data=/dev/loop7             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop7 /mnt/loop7
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop7/loop/offset : '
cat /sys/block/loop7/loop/offset : + cat /sys/block/loop7/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop7/loop/sizelimit : '
cat /sys/block/loop7/loop/sizelimit : + cat /sys/block/loop7/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop7/loop/autoclear : '
cat /sys/block/loop7/loop/autoclear : + cat /sys/block/loop7/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop7/loop/partscan : '
cat /sys/block/loop7/loop/partscan : + cat /sys/block/loop7/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop7/loop/dio : '
cat /sys/block/loop7/loop/dio : + cat /sys/block/loop7/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop2
+ truncate -s 2048M ./loop2
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop2 ./loop2
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop4         0      0         0  0 /mnt/data/linux-block/loop4   1     512
/dev/loop2         0      0         0  0 /mnt/data/linux-block/loop2   1     512
/dev/loop7         0      0         0  0 /mnt/data/linux-block/loop7   1     512
/dev/loop5         0      0         0  0 /mnt/data/linux-block/loop5   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop2
meta-data=/dev/loop2             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop2 /mnt/loop2
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop2/loop/offset : '
cat /sys/block/loop2/loop/offset : + cat /sys/block/loop2/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop2/loop/sizelimit : '
cat /sys/block/loop2/loop/sizelimit : + cat /sys/block/loop2/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop2/loop/autoclear : '
cat /sys/block/loop2/loop/autoclear : + cat /sys/block/loop2/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop2/loop/partscan : '
cat /sys/block/loop2/loop/partscan : + cat /sys/block/loop2/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop2/loop/dio : '
cat /sys/block/loop2/loop/dio : + cat /sys/block/loop2/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop9
+ truncate -s 2048M ./loop9
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop9 ./loop9
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop4         0      0         0  0 /mnt/data/linux-block/loop4   1     512
/dev/loop2         0      0         0  0 /mnt/data/linux-block/loop2   1     512
/dev/loop9         0      0         0  0 /mnt/data/linux-block/loop9   1     512
/dev/loop7         0      0         0  0 /mnt/data/linux-block/loop7   1     512
/dev/loop5         0      0         0  0 /mnt/data/linux-block/loop5   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop9
meta-data=/dev/loop9             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop9 /mnt/loop9
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop9/loop/offset : '
cat /sys/block/loop9/loop/offset : + cat /sys/block/loop9/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop9/loop/sizelimit : '
cat /sys/block/loop9/loop/sizelimit : + cat /sys/block/loop9/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop9/loop/autoclear : '
cat /sys/block/loop9/loop/autoclear : + cat /sys/block/loop9/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop9/loop/partscan : '
cat /sys/block/loop9/loop/partscan : + cat /sys/block/loop9/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop9/loop/dio : '
cat /sys/block/loop9/loop/dio : + cat /sys/block/loop9/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop1
+ truncate -s 2048M ./loop1
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop1 ./loop1
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop1         0      0         0  0 /mnt/data/linux-block/loop1   1     512
/dev/loop4         0      0         0  0 /mnt/data/linux-block/loop4   1     512
/dev/loop2         0      0         0  0 /mnt/data/linux-block/loop2   1     512
/dev/loop9         0      0         0  0 /mnt/data/linux-block/loop9   1     512
/dev/loop7         0      0         0  0 /mnt/data/linux-block/loop7   1     512
/dev/loop5         0      0         0  0 /mnt/data/linux-block/loop5   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop1
meta-data=/dev/loop1             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop1 /mnt/loop1
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop1/loop/offset : '
cat /sys/block/loop1/loop/offset : + cat /sys/block/loop1/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop1/loop/sizelimit : '
cat /sys/block/loop1/loop/sizelimit : + cat /sys/block/loop1/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop1/loop/autoclear : '
cat /sys/block/loop1/loop/autoclear : + cat /sys/block/loop1/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop1/loop/partscan : '
cat /sys/block/loop1/loop/partscan : + cat /sys/block/loop1/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop1/loop/dio : '
cat /sys/block/loop1/loop/dio : + cat /sys/block/loop1/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop8
+ truncate -s 2048M ./loop8
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop8 ./loop8
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop1         0      0         0  0 /mnt/data/linux-block/loop1   1     512
/dev/loop8         0      0         0  0 /mnt/data/linux-block/loop8   1     512
/dev/loop4         0      0         0  0 /mnt/data/linux-block/loop4   1     512
/dev/loop2         0      0         0  0 /mnt/data/linux-block/loop2   1     512
/dev/loop9         0      0         0  0 /mnt/data/linux-block/loop9   1     512
/dev/loop7         0      0         0  0 /mnt/data/linux-block/loop7   1     512
/dev/loop5         0      0         0  0 /mnt/data/linux-block/loop5   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop8
meta-data=/dev/loop8             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop8 /mnt/loop8
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop8/loop/offset : '
cat /sys/block/loop8/loop/offset : + cat /sys/block/loop8/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop8/loop/sizelimit : '
cat /sys/block/loop8/loop/sizelimit : + cat /sys/block/loop8/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop8/loop/autoclear : '
cat /sys/block/loop8/loop/autoclear : + cat /sys/block/loop8/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop8/loop/partscan : '
cat /sys/block/loop8/loop/partscan : + cat /sys/block/loop8/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop8/loop/dio : '
cat /sys/block/loop8/loop/dio : + cat /sys/block/loop8/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop3
+ truncate -s 2048M ./loop3
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop3 ./loop3
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop1         0      0         0  0 /mnt/data/linux-block/loop1   1     512
/dev/loop8         0      0         0  0 /mnt/data/linux-block/loop8   1     512
/dev/loop4         0      0         0  0 /mnt/data/linux-block/loop4   1     512
/dev/loop2         0      0         0  0 /mnt/data/linux-block/loop2   1     512
/dev/loop9         0      0         0  0 /mnt/data/linux-block/loop9   1     512
/dev/loop7         0      0         0  0 /mnt/data/linux-block/loop7   1     512
/dev/loop5         0      0         0  0 /mnt/data/linux-block/loop5   1     512
/dev/loop3         0      0         0  0 /mnt/data/linux-block/loop3   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop3
meta-data=/dev/loop3             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop3 /mnt/loop3
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop3/loop/offset : '
cat /sys/block/loop3/loop/offset : + cat /sys/block/loop3/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop3/loop/sizelimit : '
cat /sys/block/loop3/loop/sizelimit : + cat /sys/block/loop3/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop3/loop/autoclear : '
cat /sys/block/loop3/loop/autoclear : + cat /sys/block/loop3/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop3/loop/partscan : '
cat /sys/block/loop3/loop/partscan : + cat /sys/block/loop3/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop3/loop/dio : '
cat /sys/block/loop3/loop/dio : + cat /sys/block/loop3/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop6
+ truncate -s 2048M ./loop6
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop6 ./loop6
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop1         0      0         0  0 /mnt/data/linux-block/loop1   1     512
/dev/loop8         0      0         0  0 /mnt/data/linux-block/loop8   1     512
/dev/loop6         0      0         0  0 /mnt/data/linux-block/loop6   1     512
/dev/loop4         0      0         0  0 /mnt/data/linux-block/loop4   1     512
/dev/loop2         0      0         0  0 /mnt/data/linux-block/loop2   1     512
/dev/loop9         0      0         0  0 /mnt/data/linux-block/loop9   1     512
/dev/loop7         0      0         0  0 /mnt/data/linux-block/loop7   1     512
/dev/loop5         0      0         0  0 /mnt/data/linux-block/loop5   1     512
/dev/loop3         0      0         0  0 /mnt/data/linux-block/loop3   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop6
meta-data=/dev/loop6             isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop6 /mnt/loop6
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop6/loop/offset : '
cat /sys/block/loop6/loop/offset : + cat /sys/block/loop6/loop/offset 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop6/loop/sizelimit : '
cat /sys/block/loop6/loop/sizelimit : + cat /sys/block/loop6/loop/sizelimit 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop6/loop/autoclear : '
cat /sys/block/loop6/loop/autoclear : + cat /sys/block/loop6/loop/autoclear 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop6/loop/partscan : '
cat /sys/block/loop6/loop/partscan : + cat /sys/block/loop6/loop/partscan 0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop6/loop/dio : '
cat /sys/block/loop6/loop/dio : + cat /sys/block/loop6/loop/dio 1
+ for i in shuf -i 1-$NN -n $NN
+ mkdir -p /mnt/loop10
+ truncate -s 2048M ./loop10
+ /mnt/data/util-linux/losetup --direct-io=on /dev/loop10 ./loop10
+ /mnt/data/util-linux/losetup
NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC

/dev/loop1          0      0         0  0 /mnt/data/linux-block/loop1    1     512
/dev/loop8          0      0         0  0 /mnt/data/linux-block/loop8    1     512
/dev/loop6          0      0         0  0 /mnt/data/linux-block/loop6    1     512
/dev/loop4          0      0         0  0 /mnt/data/linux-block/loop4    1     512
/dev/loop2          0      0         0  0 /mnt/data/linux-block/loop2    1     512
/dev/loop9          0      0         0  0 /mnt/data/linux-block/loop9    1     512
/dev/loop7          0      0         0  0 /mnt/data/linux-block/loop7    1     512
/dev/loop5          0      0         0  0 /mnt/data/linux-block/loop5    1     512
/dev/loop3          0      0         0  0 /mnt/data/linux-block/loop3    1     512
/dev/loop10         0      0         0  0 /mnt/data/linux-block/loop10   1     512
+ sleep 1
+ mkfs.xfs -f /dev/loop10
meta-data=/dev/loop10            isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0
data     =                       bsize=4096   blocks=524288, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Discarding blocks...Done.
+ mount /dev/loop10 /mnt/loop10
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop10/loop/offset : '
cat /sys/block/loop10/loop/offset : + cat /sys/block/loop10/loop/offset
0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop10/loop/sizelimit : '
cat /sys/block/loop10/loop/sizelimit : + cat /sys/block/loop10/loop/sizelimit
0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop10/loop/autoclear : '
cat /sys/block/loop10/loop/autoclear : + cat /sys/block/loop10/loop/autoclear
0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop10/loop/partscan : '
cat /sys/block/loop10/loop/partscan : + cat /sys/block/loop10/loop/partscan
0
+ for attr in offset sizelimit autoclear partscan dio
+ echo -n 'cat /sys/block/loop10/loop/dio : '
cat /sys/block/loop10/loop/dio : + cat /sys/block/loop10/loop/dio
1
+ mount
+ grep loop
/dev/loop4 on /mnt/loop4 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop5 on /mnt/loop5 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop7 on /mnt/loop7 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop2 on /mnt/loop2 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop9 on /mnt/loop9 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop1 on /mnt/loop1 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop8 on /mnt/loop8 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop3 on /mnt/loop3 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop6 on /mnt/loop6 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/loop10 on /mnt/loop10 type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota)
+ dmesg -c

[ 1241.220179] XFS (loop8): Unmounting Filesystem
[ 1241.381829] XFS (loop2): Unmounting Filesystem
[ 1241.498565] XFS (loop1): Unmounting Filesystem
[ 1241.613692] XFS (loop7): Unmounting Filesystem
[ 1241.730380] XFS (loop3): Unmounting Filesystem
[ 1248.256956] loop: module loaded
[ 1248.331571] loop4: detected capacity change from 0 to 4194304
[ 1249.434320] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1249.439367] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1249.531030] XFS (loop4): Mounting V5 Filesystem
[ 1249.548436] XFS (loop4): Ending clean mount
[ 1249.554274] xfs filesystem being mounted at /mnt/loop4 supports timestamps until 2038 (0x7fffffff)
[ 1249.652646] loop5: detected capacity change from 0 to 4194304
[ 1250.750374] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1250.754859] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1250.845019] XFS (loop5): Mounting V5 Filesystem
[ 1250.860792] XFS (loop5): Ending clean mount
[ 1250.868231] xfs filesystem being mounted at /mnt/loop5 supports timestamps until 2038 (0x7fffffff)
[ 1250.965924] loop7: detected capacity change from 0 to 4194304
[ 1252.063735] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1252.068024] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1252.161562] XFS (loop7): Mounting V5 Filesystem
[ 1252.178133] XFS (loop7): Ending clean mount
[ 1252.182782] xfs filesystem being mounted at /mnt/loop7 supports timestamps until 2038 (0x7fffffff)
[ 1252.279860] loop2: detected capacity change from 0 to 4194304
[ 1253.379330] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1253.383928] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1253.471016] XFS (loop2): Mounting V5 Filesystem
[ 1253.486297] XFS (loop2): Ending clean mount
[ 1253.491426] xfs filesystem being mounted at /mnt/loop2 supports timestamps until 2038 (0x7fffffff)
[ 1253.589263] loop9: detected capacity change from 0 to 4194304
[ 1254.683298] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1254.687374] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1254.776304] XFS (loop9): Mounting V5 Filesystem
[ 1254.793984] XFS (loop9): Ending clean mount
[ 1254.800826] xfs filesystem being mounted at /mnt/loop9 supports timestamps until 2038 (0x7fffffff)
[ 1254.900277] loop1: detected capacity change from 0 to 4194304
[ 1255.997305] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1256.001931] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1256.089698] XFS (loop1): Mounting V5 Filesystem
[ 1256.110355] XFS (loop1): Ending clean mount
[ 1256.115614] xfs filesystem being mounted at /mnt/loop1 supports timestamps until 2038 (0x7fffffff)
[ 1256.215617] loop8: detected capacity change from 0 to 4194304
[ 1257.315422] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1257.319657] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1257.407754] XFS (loop8): Mounting V5 Filesystem
[ 1257.422580] XFS (loop8): Ending clean mount
[ 1257.429114] xfs filesystem being mounted at /mnt/loop8 supports timestamps until 2038 (0x7fffffff)
[ 1257.529780] loop3: detected capacity change from 0 to 4194304
[ 1258.634266] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1258.638672] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1258.728060] XFS (loop3): Mounting V5 Filesystem
[ 1258.744939] XFS (loop3): Ending clean mount
[ 1258.749639] xfs filesystem being mounted at /mnt/loop3 supports timestamps until 2038 (0x7fffffff)
[ 1258.849570] loop6: detected capacity change from 0 to 4194304
[ 1259.956273] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1259.960716] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1260.050870] XFS (loop6): Mounting V5 Filesystem
[ 1260.067469] XFS (loop6): Ending clean mount
[ 1260.072475] xfs filesystem being mounted at /mnt/loop6 supports timestamps until 2038 (0x7fffffff)
[ 1260.170808] loop10: detected capacity change from 0 to 4194304
[ 1261.274342] __blkdev_issue_discard 82 sector 0 nr_sects 4194304
[ 1261.278068] __blkdev_issue_write_zeroes 242 sector 2097200 nr_sects 20480
[ 1261.369702] XFS (loop10): Mounting V5 Filesystem
[ 1261.385775] XFS (loop10): Ending clean mount
[ 1261.390010] xfs filesystem being mounted at /mnt/loop10 supports timestamps until 2038 (0x7fffffff)
+ df -h /mnt/loop1 /mnt/loop10 /mnt/loop2 /mnt/loop3 /mnt/loop4 /mnt/loop5 /mnt/loop6 /mnt/loop7 /mnt/loop8 /mnt/loop9
Filesystem      Size  Used Avail Use% Mounted on
/dev/loop1      2.0G   47M  2.0G   3% /mnt/loop1
/dev/loop10     2.0G   47M  2.0G   3% /mnt/loop10
/dev/loop2      2.0G   47M  2.0G   3% /mnt/loop2
/dev/loop3      2.0G   47M  2.0G   3% /mnt/loop3
/dev/loop4      2.0G   47M  2.0G   3% /mnt/loop4
/dev/loop5      2.0G   47M  2.0G   3% /mnt/loop5
/dev/loop6      2.0G   47M  2.0G   3% /mnt/loop6
/dev/loop7      2.0G   47M  2.0G   3% /mnt/loop7
/dev/loop8      2.0G   47M  2.0G   3% /mnt/loop8
/dev/loop9      2.0G   47M  2.0G   3% /mnt/loop9

++ shuf -i 1-10 -n 10
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop1/testfile
+ fio fio/verify.fio --filename=/mnt/loop1/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][81.2%][r=19.8MiB/s][r=5058 IOPS][eta 00m:27s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=7408: Mon Feb 14 22:15:22 2022
read: IOPS=4719, BW=18.4MiB/s (19.3MB/s)(647MiB/35076msec)

    slat (usec): min=7, max=4436, avg=11.94, stdev=28.78
    clat (usec): min=515, max=198069, avg=3376.08, stdev=2058.70
     lat (usec): min=568, max=198084, avg=3388.12, stdev=2059.98
    clat percentiles (usec):
     |  1.00th=[ 2409],  5.00th=[ 2474], 10.00th=[ 2507], 20.00th=[ 2638],
     | 30.00th=[ 2737], 40.00th=[ 2933], 50.00th=[ 3326], 60.00th=[ 3654],
     | 70.00th=[ 3818], 80.00th=[ 3916], 90.00th=[ 4178], 95.00th=[ 4359],
     | 99.00th=[ 6325], 99.50th=[ 6915], 99.90th=[ 8455], 99.95th=[ 9110],
     | 99.99th=[12780]
  write: IOPS=3176, BW=12.4MiB/s (13.0MB/s)(1024MiB/82525msec); 0 zone resets
    slat (usec): min=9, max=84187, avg=29.25, stdev=349.74
    clat (usec): min=436, max=268013, avg=5006.25, stdev=4520.52
     lat (usec): min=616, max=268042, avg=5035.65, stdev=4544.01
    clat percentiles (msec):
     |  1.00th=[    3],  5.00th=[    3], 10.00th=[    4], 20.00th=[    4],
     | 30.00th=[    4], 40.00th=[    4], 50.00th=[    4], 60.00th=[    5],
     | 70.00th=[    6], 80.00th=[    6], 90.00th=[    7], 95.00th=[   11],
     | 99.00th=[   25], 99.50th=[   31], 99.90th=[   48], 99.95th=[   67],
     | 99.99th=[  124]
   bw (  KiB/s): min= 3008, max=19248, per=100.00%, avg=12709.96, stdev=3287.35, samples=165
   iops        : min=  752, max= 4812, avg=3177.50, stdev=821.86, samples=165
  lat (usec)   : 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.02%, 4=65.48%, 10=31.26%, 20=2.36%, 50=0.82%
  lat (msec)   : 100=0.04%, 250=0.01%, 500=0.01%
  cpu          : usr=2.05%, sys=9.14%, ctx=422964, majf=0, minf=3899
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165557,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.4MiB/s (19.3MB/s), 18.4MiB/s-18.4MiB/s (19.3MB/s-19.3MB/s), io=647MiB (678MB), run=35076-35076msec
WRITE: bw=12.4MiB/s (13.0MB/s), 12.4MiB/s-12.4MiB/s (13.0MB/s-13.0MB/s), io=1024MiB (1074MB), run=82525-82525msec

Disk stats (read/write):
loop1: ios=164509/275092, merge=0/1727, ticks=554589/1384386, in_queue=1947254, util=99.77%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop2/testfile
+ fio fio/verify.fio --filename=/mnt/loop2/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][81.4%][r=16.4MiB/s][r=4187 IOPS][eta 00m:27s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=7700: Mon Feb 14 22:17:21 2022
read: IOPS=4600, BW=18.0MiB/s (18.8MB/s)(647MiB/35979msec)

    slat (usec): min=7, max=3925, avg=12.38, stdev=22.80
    clat (usec): min=245, max=125327, avg=3463.42, stdev=1588.96
     lat (usec): min=287, max=125347, avg=3475.91, stdev=1590.52
    clat percentiles (usec):
     |  1.00th=[ 2442],  5.00th=[ 2507], 10.00th=[ 2540], 20.00th=[ 2704],
     | 30.00th=[ 2835], 40.00th=[ 3130], 50.00th=[ 3523], 60.00th=[ 3752],
     | 70.00th=[ 3851], 80.00th=[ 3949], 90.00th=[ 4228], 95.00th=[ 4424],
     | 99.00th=[ 6587], 99.50th=[ 7111], 99.90th=[ 8848], 99.95th=[10290],
     | 99.99th=[74974]
  write: IOPS=3168, BW=12.4MiB/s (13.0MB/s)(1024MiB/82741msec); 0 zone resets
    slat (usec): min=9, max=30339, avg=26.76, stdev=128.31
    clat (usec): min=325, max=131766, avg=5021.92, stdev=3882.26
     lat (usec): min=564, max=132078, avg=5048.82, stdev=3887.07
    clat percentiles (usec):
     |  1.00th=[ 2868],  5.00th=[ 2999], 10.00th=[ 3097], 20.00th=[ 3195],
     | 30.00th=[ 3326], 40.00th=[ 3523], 50.00th=[ 3818], 60.00th=[ 4686],
     | 70.00th=[ 5211], 80.00th=[ 5669], 90.00th=[ 6652], 95.00th=[10290],
     | 99.00th=[23987], 99.50th=[29754], 99.90th=[43254], 99.95th=[49546],
     | 99.99th=[82314]
   bw (  KiB/s): min= 4512, max=18968, per=99.68%, avg=12633.56, stdev=2872.42, samples=166
   iops        : min= 1128, max= 4742, avg=3158.38, stdev=718.11, samples=166
  lat (usec)   : 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.02%, 4=63.56%, 10=33.19%, 20=2.33%, 50=0.85%
  lat (msec)   : 100=0.03%, 250=0.01%
  cpu          : usr=2.05%, sys=9.25%, ctx=423277, majf=0, minf=3898
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165523,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.0MiB/s (18.8MB/s), 18.0MiB/s-18.0MiB/s (18.8MB/s-18.8MB/s), io=647MiB (678MB), run=35979-35979msec
WRITE: bw=12.4MiB/s (13.0MB/s), 12.4MiB/s-12.4MiB/s (13.0MB/s-13.0MB/s), io=1024MiB (1074MB), run=82741-82741msec

Disk stats (read/write):
loop2: ios=165009/275205, merge=0/792, ticks=570345/1373899, in_queue=1951630, util=99.83%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop4/testfile
+ fio fio/verify.fio --filename=/mnt/loop4/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][81.1%][r=20.9MiB/s][r=5356 IOPS][eta 00m:27s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=7852: Mon Feb 14 22:19:18 2022
read: IOPS=4806, BW=18.8MiB/s (19.7MB/s)(647MiB/34475msec)

    slat (usec): min=7, max=452, avg=12.38, stdev= 5.62
    clat (usec): min=297, max=178459, avg=3314.45, stdev=1832.28
     lat (usec): min=349, max=178470, avg=3326.93, stdev=1833.07
    clat percentiles (usec):
     |  1.00th=[ 2409],  5.00th=[ 2474], 10.00th=[ 2507], 20.00th=[ 2573],
     | 30.00th=[ 2704], 40.00th=[ 2868], 50.00th=[ 3261], 60.00th=[ 3589],
     | 70.00th=[ 3785], 80.00th=[ 3884], 90.00th=[ 4113], 95.00th=[ 4293],
     | 99.00th=[ 6063], 99.50th=[ 6849], 99.90th=[ 8291], 99.95th=[ 8979],
     | 99.99th=[17171]
  write: IOPS=3184, BW=12.4MiB/s (13.0MB/s)(1024MiB/82307msec); 0 zone resets
    slat (usec): min=9, max=42384, avg=27.19, stdev=150.70
    clat (usec): min=409, max=118493, avg=4995.02, stdev=4056.09
     lat (usec): min=467, max=118526, avg=5022.36, stdev=4061.17
    clat percentiles (usec):
     |  1.00th=[ 2835],  5.00th=[ 2966], 10.00th=[ 3064], 20.00th=[ 3163],
     | 30.00th=[ 3261], 40.00th=[ 3425], 50.00th=[ 3818], 60.00th=[ 4621],
     | 70.00th=[ 5211], 80.00th=[ 5669], 90.00th=[ 6587], 95.00th=[10159],
     | 99.00th=[25035], 99.50th=[30540], 99.90th=[46400], 99.95th=[64750],
     | 99.99th=[86508]
   bw (  KiB/s): min= 4560, max=19392, per=99.77%, avg=12710.01, stdev=2951.46, samples=165
   iops        : min= 1140, max= 4848, avg=3177.50, stdev=737.86, samples=165
  lat (usec)   : 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.03%, 4=65.52%, 10=31.26%, 20=2.29%, 50=0.84%
  lat (msec)   : 100=0.05%, 250=0.01%
  cpu          : usr=2.23%, sys=9.52%, ctx=422696, majf=0, minf=3901
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165701,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.8MiB/s (19.7MB/s), 18.8MiB/s-18.8MiB/s (19.7MB/s-19.7MB/s), io=647MiB (679MB), run=34475-34475msec
WRITE: bw=12.4MiB/s (13.0MB/s), 12.4MiB/s-12.4MiB/s (13.0MB/s-13.0MB/s), io=1024MiB (1074MB), run=82307-82307msec

Disk stats (read/write):
loop4: ios=164887/274862, merge=0/1165, ticks=545520/1364713, in_queue=1918059, util=99.80%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop3/testfile
+ fio fio/verify.fio --filename=/mnt/loop3/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][81.1%][r=18.4MiB/s][r=4713 IOPS][eta 00m:27s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=7941: Mon Feb 14 22:21:15 2022
read: IOPS=4730, BW=18.5MiB/s (19.4MB/s)(648MiB/35062msec)

    slat (usec): min=7, max=5336, avg=11.28, stdev=25.22
    clat (usec): min=202, max=107070, avg=3369.29, stdev=1411.41
     lat (usec): min=231, max=107086, avg=3380.66, stdev=1413.05
    clat percentiles (usec):
     |  1.00th=[ 2376],  5.00th=[ 2442], 10.00th=[ 2507], 20.00th=[ 2638],
     | 30.00th=[ 2769], 40.00th=[ 2966], 50.00th=[ 3326], 60.00th=[ 3654],
     | 70.00th=[ 3785], 80.00th=[ 3884], 90.00th=[ 4146], 95.00th=[ 4293],
     | 99.00th=[ 6325], 99.50th=[ 6980], 99.90th=[10028], 99.95th=[11994],
     | 99.99th=[64226]
  write: IOPS=3218, BW=12.6MiB/s (13.2MB/s)(1024MiB/81458msec); 0 zone resets
    slat (usec): min=9, max=54830, avg=25.50, stdev=174.11
    clat (usec): min=355, max=81015, avg=4944.97, stdev=3889.15
     lat (usec): min=430, max=81049, avg=4970.61, stdev=3895.80
    clat percentiles (usec):
     |  1.00th=[ 2868],  5.00th=[ 2999], 10.00th=[ 3097], 20.00th=[ 3195],
     | 30.00th=[ 3261], 40.00th=[ 3425], 50.00th=[ 3687], 60.00th=[ 4490],
     | 70.00th=[ 5080], 80.00th=[ 5604], 90.00th=[ 6521], 95.00th=[10159],
     | 99.00th=[25035], 99.50th=[30802], 99.90th=[43779], 99.95th=[52691],
     | 99.99th=[68682]
   bw (  KiB/s): min= 4072, max=19128, per=100.00%, avg=12873.14, stdev=2986.77, samples=163
   iops        : min= 1018, max= 4782, avg=3218.17, stdev=746.68, samples=163
  lat (usec)   : 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.02%, 4=66.71%, 10=30.09%, 20=2.29%, 50=0.83%
  lat (msec)   : 100=0.04%, 250=0.01%
  cpu          : usr=2.02%, sys=8.88%, ctx=424486, majf=0, minf=3905
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165854,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.5MiB/s (19.4MB/s), 18.5MiB/s-18.5MiB/s (19.4MB/s-19.4MB/s), io=648MiB (679MB), run=35062-35062msec
WRITE: bw=12.6MiB/s (13.2MB/s), 12.6MiB/s-12.6MiB/s (13.2MB/s-13.2MB/s), io=1024MiB (1074MB), run=81458-81458msec

Disk stats (read/write):
loop3: ios=164700/274567, merge=0/1211, ticks=554381/1352572, in_queue=1914775, util=99.84%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop8/testfile
+ fio fio/verify.fio --filename=/mnt/loop8/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][81.5%][r=18.6MiB/s][r=4771 IOPS][eta 00m:28s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=8004: Mon Feb 14 22:23:19 2022
read: IOPS=4749, BW=18.6MiB/s (19.5MB/s)(647MiB/34896msec)

    slat (usec): min=7, max=5788, avg=11.65, stdev=32.39
    clat (usec): min=264, max=168300, avg=3355.35, stdev=1792.07
     lat (usec): min=295, max=168311, avg=3367.10, stdev=1793.67
    clat percentiles (usec):
     |  1.00th=[ 2409],  5.00th=[ 2474], 10.00th=[ 2507], 20.00th=[ 2606],
     | 30.00th=[ 2737], 40.00th=[ 2933], 50.00th=[ 3326], 60.00th=[ 3654],
     | 70.00th=[ 3785], 80.00th=[ 3884], 90.00th=[ 4146], 95.00th=[ 4293],
     | 99.00th=[ 6325], 99.50th=[ 6849], 99.90th=[ 9503], 99.95th=[10945],
     | 99.99th=[14484]
  write: IOPS=2963, BW=11.6MiB/s (12.1MB/s)(1024MiB/88464msec); 0 zone resets
    slat (usec): min=9, max=32981, avg=29.19, stdev=157.06
    clat (usec): min=441, max=108702, avg=5368.69, stdev=3858.95
     lat (usec): min=640, max=108726, avg=5398.04, stdev=3865.29
    clat percentiles (usec):
     |  1.00th=[ 2966],  5.00th=[ 3130], 10.00th=[ 3228], 20.00th=[ 3359],
     | 30.00th=[ 3621], 40.00th=[ 3916], 50.00th=[ 4359], 60.00th=[ 4948],
     | 70.00th=[ 5538], 80.00th=[ 6259], 90.00th=[ 7767], 95.00th=[10290],
     | 99.00th=[24511], 99.50th=[29492], 99.90th=[42730], 99.95th=[52167],
     | 99.99th=[87557]
   bw (  KiB/s): min= 4488, max=19328, per=99.96%, avg=11848.32, stdev=2947.65, samples=177
   iops        : min= 1122, max= 4832, avg=2962.08, stdev=736.91, samples=177
  lat (usec)   : 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.02%, 4=59.16%, 10=37.59%, 20=2.33%, 50=0.84%
  lat (msec)   : 100=0.03%, 250=0.01%
  cpu          : usr=2.17%, sys=9.15%, ctx=423338, majf=0, minf=3902
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165736,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.6MiB/s (19.5MB/s), 18.6MiB/s-18.6MiB/s (19.5MB/s-19.5MB/s), io=647MiB (679MB), run=34896-34896msec
WRITE: bw=11.6MiB/s (12.1MB/s), 11.6MiB/s-11.6MiB/s (12.1MB/s-12.1MB/s), io=1024MiB (1074MB), run=88464-88464msec

Disk stats (read/write):
loop8: ios=164585/275039, merge=0/998, ticks=551377/1460715, in_queue=2019766, util=99.85%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop7/testfile
+ fio fio/verify.fio --filename=/mnt/loop7/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][81.7%][r=19.4MiB/s][r=4957 IOPS][eta 00m:26s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=8069: Mon Feb 14 22:25:15 2022
read: IOPS=4741, BW=18.5MiB/s (19.4MB/s)(646MiB/34895msec)

    slat (usec): min=7, max=5653, avg=11.49, stdev=25.14
    clat (usec): min=262, max=112471, avg=3361.01, stdev=1505.71
     lat (usec): min=314, max=112488, avg=3372.59, stdev=1507.24
    clat percentiles (usec):
     |  1.00th=[ 2442],  5.00th=[ 2507], 10.00th=[ 2540], 20.00th=[ 2638],
     | 30.00th=[ 2769], 40.00th=[ 2966], 50.00th=[ 3326], 60.00th=[ 3621],
     | 70.00th=[ 3785], 80.00th=[ 3884], 90.00th=[ 4146], 95.00th=[ 4293],
     | 99.00th=[ 6259], 99.50th=[ 6783], 99.90th=[ 9110], 99.95th=[11469],
     | 99.99th=[73925]
  write: IOPS=3234, BW=12.6MiB/s (13.2MB/s)(1024MiB/81041msec); 0 zone resets
    slat (usec): min=9, max=92800, avg=26.58, stdev=238.92
    clat (usec): min=465, max=174470, avg=4918.39, stdev=4191.56
     lat (usec): min=490, max=174492, avg=4945.12, stdev=4199.86
    clat percentiles (msec):
     |  1.00th=[    3],  5.00th=[    3], 10.00th=[    4], 20.00th=[    4],
     | 30.00th=[    4], 40.00th=[    4], 50.00th=[    4], 60.00th=[    5],
     | 70.00th=[    6], 80.00th=[    6], 90.00th=[    7], 95.00th=[   11],
     | 99.00th=[   24], 99.50th=[   30], 99.90th=[   43], 99.95th=[   66],
     | 99.99th=[  131]
   bw (  KiB/s): min= 2208, max=19560, per=100.00%, avg=12947.73, stdev=3018.88, samples=162
   iops        : min=  552, max= 4890, avg=3236.91, stdev=754.70, samples=162
  lat (usec)   : 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.04%, 4=66.35%, 10=30.40%, 20=2.36%, 50=0.78%
  lat (msec)   : 100=0.03%, 250=0.02%
  cpu          : usr=1.98%, sys=9.14%, ctx=423059, majf=0, minf=3895
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165460,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.5MiB/s (19.4MB/s), 18.5MiB/s-18.5MiB/s (19.4MB/s-19.4MB/s), io=646MiB (678MB), run=34895-34895msec
WRITE: bw=12.6MiB/s (13.2MB/s), 12.6MiB/s-12.6MiB/s (13.2MB/s-13.2MB/s), io=1024MiB (1074MB), run=81041-81041msec

Disk stats (read/write):
loop7: ios=164861/274762, merge=0/1097, ticks=553467/1339136, in_queue=1900082, util=99.85%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop6/testfile
+ fio fio/verify.fio --filename=/mnt/loop6/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][81.6%][r=20.4MiB/s][r=5224 IOPS][eta 00m:26s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=8138: Mon Feb 14 22:27:10 2022
read: IOPS=4756, BW=18.6MiB/s (19.5MB/s)(647MiB/34821msec)

    slat (usec): min=7, max=4753, avg=11.17, stdev=30.09
    clat (usec): min=660, max=176614, avg=3350.69, stdev=1853.67
     lat (usec): min=710, max=176622, avg=3361.95, stdev=1855.21
    clat percentiles (usec):
     |  1.00th=[ 2376],  5.00th=[ 2474], 10.00th=[ 2507], 20.00th=[ 2638],
     | 30.00th=[ 2737], 40.00th=[ 2966], 50.00th=[ 3326], 60.00th=[ 3621],
     | 70.00th=[ 3785], 80.00th=[ 3884], 90.00th=[ 4113], 95.00th=[ 4228],
     | 99.00th=[ 6063], 99.50th=[ 6718], 99.90th=[10421], 99.95th=[12780],
     | 99.99th=[16581]
  write: IOPS=3273, BW=12.8MiB/s (13.4MB/s)(1024MiB/80088msec); 0 zone resets
    slat (usec): min=9, max=93505, avg=26.54, stdev=253.80
    clat (usec): min=465, max=144963, avg=4860.35, stdev=3706.66
     lat (usec): min=577, max=145285, avg=4887.03, stdev=3723.14
    clat percentiles (usec):
     |  1.00th=[ 2769],  5.00th=[ 2900], 10.00th=[ 2999], 20.00th=[ 3097],
     | 30.00th=[ 3228], 40.00th=[ 3392], 50.00th=[ 3851], 60.00th=[ 4621],
     | 70.00th=[ 5080], 80.00th=[ 5473], 90.00th=[ 6259], 95.00th=[10159],
     | 99.00th=[22152], 99.50th=[28443], 99.90th=[38536], 99.95th=[49546],
     | 99.99th=[70779]
   bw (  KiB/s): min= 3432, max=19704, per=100.00%, avg=13107.20, stdev=3183.74, samples=160
   iops        : min=  858, max= 4926, avg=3276.80, stdev=795.93, samples=160
  lat (usec)   : 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.05%, 4=65.21%, 10=31.53%, 20=2.40%, 50=0.77%
  lat (msec)   : 100=0.03%, 250=0.01%
  cpu          : usr=2.04%, sys=8.84%, ctx=422363, majf=0, minf=3900
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165635,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.6MiB/s (19.5MB/s), 18.6MiB/s-18.6MiB/s (19.5MB/s-19.5MB/s), io=647MiB (678MB), run=34821-34821msec
WRITE: bw=12.8MiB/s (13.4MB/s), 12.8MiB/s-12.8MiB/s (13.4MB/s-13.4MB/s), io=1024MiB (1074MB), run=80088-80088msec

Disk stats (read/write):
loop6: ios=165432/274759, merge=0/1560, ticks=553349/1326413, in_queue=1887360, util=99.85%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop10/testfile
+ fio fio/verify.fio --filename=/mnt/loop10/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=0): [f(1)][100.0%][r=15.2MiB/s][r=3898 IOPS][eta 00m:00s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=8226: Mon Feb 14 22:29:08 2022
read: IOPS=4648, BW=18.2MiB/s (19.0MB/s)(647MiB/35634msec)

    slat (usec): min=7, max=3527, avg=12.14, stdev=26.31
    clat (usec): min=197, max=42316, avg=3428.06, stdev=870.56
     lat (usec): min=227, max=42335, avg=3440.30, stdev=873.41
    clat percentiles (usec):
     |  1.00th=[ 2442],  5.00th=[ 2507], 10.00th=[ 2540], 20.00th=[ 2671],
     | 30.00th=[ 2802], 40.00th=[ 3064], 50.00th=[ 3425], 60.00th=[ 3720],
     | 70.00th=[ 3851], 80.00th=[ 3949], 90.00th=[ 4228], 95.00th=[ 4424],
     | 99.00th=[ 6456], 99.50th=[ 7046], 99.90th=[ 8586], 99.95th=[ 9896],
     | 99.99th=[17433]
  write: IOPS=3230, BW=12.6MiB/s (13.2MB/s)(1024MiB/81141msec); 0 zone resets
    slat (usec): min=9, max=162004, avg=28.38, stdev=482.65
    clat (usec): min=435, max=278095, avg=4922.76, stdev=5104.52
     lat (usec): min=520, max=278126, avg=4951.28, stdev=5152.39
    clat percentiles (msec):
     |  1.00th=[    3],  5.00th=[    3], 10.00th=[    3], 20.00th=[    4],
     | 30.00th=[    4], 40.00th=[    4], 50.00th=[    4], 60.00th=[    5],
     | 70.00th=[    6], 80.00th=[    6], 90.00th=[    7], 95.00th=[   10],
     | 99.00th=[   25], 99.50th=[   32], 99.90th=[   61], 99.95th=[   80],
     | 99.99th=[  194]
   bw (  KiB/s): min= 1880, max=20304, per=99.61%, avg=12873.77, stdev=3180.18, samples=163
   iops        : min=  470, max= 5076, avg=3218.34, stdev=795.03, samples=163
  lat (usec)   : 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.05%, 4=64.31%, 10=32.82%, 20=1.96%, 50=0.76%
  lat (msec)   : 100=0.07%, 250=0.02%, 500=0.01%
  cpu          : usr=2.02%, sys=8.97%, ctx=423387, majf=0, minf=3902
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165635,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.2MiB/s (19.0MB/s), 18.2MiB/s-18.2MiB/s (19.0MB/s-19.0MB/s), io=647MiB (678MB), run=35634-35634msec
WRITE: bw=12.6MiB/s (13.2MB/s), 12.6MiB/s-12.6MiB/s (13.2MB/s-13.2MB/s), io=1024MiB (1074MB), run=81141-81141msec

Disk stats (read/write):
loop10: ios=164704/274985, merge=0/1497, ticks=563065/1356524, in_queue=1927980, util=99.83%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop5/testfile
+ fio fio/verify.fio --filename=/mnt/loop5/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][82.0%][r=16.7MiB/s][r=4281 IOPS][eta 00m:27s]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=8337: Mon Feb 14 22:31:11 2022
read: IOPS=4546, BW=17.8MiB/s (18.6MB/s)(647MiB/36422msec)

    slat (usec): min=7, max=1962, avg=12.78, stdev=11.72
    clat (usec): min=315, max=191618, avg=3504.53, stdev=2050.26
     lat (usec): min=346, max=191634, avg=3517.41, stdev=2051.11
    clat percentiles (usec):
     |  1.00th=[ 2442],  5.00th=[ 2540], 10.00th=[ 2573], 20.00th=[ 2737],
     | 30.00th=[ 2900], 40.00th=[ 3195], 50.00th=[ 3556], 60.00th=[ 3752],
     | 70.00th=[ 3884], 80.00th=[ 3982], 90.00th=[ 4293], 95.00th=[ 4424],
     | 99.00th=[ 6587], 99.50th=[ 7111], 99.90th=[10290], 99.95th=[13304],
     | 99.99th=[35390]
  write: IOPS=3034, BW=11.9MiB/s (12.4MB/s)(1024MiB/86397msec); 0 zone resets
    slat (usec): min=9, max=80013, avg=27.65, stdev=208.54
    clat (usec): min=332, max=98007, avg=5244.13, stdev=4379.37
     lat (usec): min=528, max=98034, avg=5271.94, stdev=4386.11
    clat percentiles (usec):
     |  1.00th=[ 2966],  5.00th=[ 3097], 10.00th=[ 3195], 20.00th=[ 3294],
     | 30.00th=[ 3392], 40.00th=[ 3589], 50.00th=[ 3884], 60.00th=[ 4555],
     | 70.00th=[ 5342], 80.00th=[ 5932], 90.00th=[ 7701], 95.00th=[10945],
     | 99.00th=[26346], 99.50th=[32637], 99.90th=[53216], 99.95th=[63701],
     | 99.99th=[86508]
   bw (  KiB/s): min= 4280, max=18960, per=99.92%, avg=12127.60, stdev=3143.79, samples=173
   iops        : min= 1070, max= 4740, avg=3031.83, stdev=785.95, samples=173
  lat (usec)   : 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.03%, 4=63.30%, 10=33.04%, 20=2.67%, 50=0.88%
  lat (msec)   : 100=0.08%, 250=0.01%
  cpu          : usr=2.01%, sys=9.26%, ctx=422718, majf=0, minf=3898
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165588,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=17.8MiB/s (18.6MB/s), 17.8MiB/s-17.8MiB/s (18.6MB/s-18.6MB/s), io=647MiB (678MB), run=36422-36422msec
WRITE: bw=11.9MiB/s (12.4MB/s), 11.9MiB/s-11.9MiB/s (12.4MB/s-12.4MB/s), io=1024MiB (1074MB), run=86397-86397msec

Disk stats (read/write):
loop5: ios=165482/274893, merge=0/888, ticks=579133/1437227, in_queue=2024581, util=99.75%
+ for i in shuf -i 1-$NN -n $NN
+ fallocate -o 0 -l 524288000 /mnt/loop9/testfile
+ fio fio/verify.fio --filename=/mnt/loop9/testfile
write-and-verify: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=16 fio-3.27
Starting 1 process
write-and-verify: Laying out IO file (1 file / 1024MiB)
Jobs: 1 (f=1): [V(1)][81.1%][r=18.9MiB/s][r=4830 IOPS][eta 00m:27s]]
write-and-verify: (groupid=0, jobs=1): err= 0: pid=8513: Mon Feb 14 22:33:08 2022
read: IOPS=4665, BW=18.2MiB/s (19.1MB/s)(647MiB/35492msec)

    slat (usec): min=7, max=3920, avg=12.76, stdev=20.93
    clat (usec): min=205, max=58280, avg=3414.45, stdev=977.48
     lat (usec): min=235, max=58298, avg=3427.32, stdev=980.02
    clat percentiles (usec):
     |  1.00th=[ 2442],  5.00th=[ 2507], 10.00th=[ 2540], 20.00th=[ 2671],
     | 30.00th=[ 2802], 40.00th=[ 2999], 50.00th=[ 3392], 60.00th=[ 3720],
     | 70.00th=[ 3851], 80.00th=[ 3949], 90.00th=[ 4228], 95.00th=[ 4424],
     | 99.00th=[ 6194], 99.50th=[ 6915], 99.90th=[ 8586], 99.95th=[10290],
     | 99.99th=[32637]
  write: IOPS=3236, BW=12.6MiB/s (13.3MB/s)(1024MiB/80995msec); 0 zone resets
    slat (usec): min=9, max=28361, avg=25.61, stdev=119.40
    clat (usec): min=299, max=268878, avg=4916.61, stdev=4152.62
     lat (usec): min=654, max=268907, avg=4942.36, stdev=4157.14
    clat percentiles (msec):
     |  1.00th=[    3],  5.00th=[    3], 10.00th=[    4], 20.00th=[    4],
     | 30.00th=[    4], 40.00th=[    4], 50.00th=[    4], 60.00th=[    5],
     | 70.00th=[    6], 80.00th=[    6], 90.00th=[    7], 95.00th=[   11],
     | 99.00th=[   24], 99.50th=[   29], 99.90th=[   39], 99.95th=[   47],
     | 99.99th=[  157]
   bw (  KiB/s): min= 2904, max=19120, per=100.00%, avg=12947.98, stdev=3093.01, samples=162
   iops        : min=  726, max= 4780, avg=3236.96, stdev=773.22, samples=162
  lat (usec)   : 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.01%
  lat (msec)   : 2=0.02%, 4=64.96%, 10=31.86%, 20=2.34%, 50=0.80%
  lat (msec)   : 100=0.01%, 250=0.01%, 500=0.01%
  cpu          : usr=2.01%, sys=9.38%, ctx=423986, majf=0, minf=3899
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=165598,262144,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=16

Run status group 0 (all jobs):
READ: bw=18.2MiB/s (19.1MB/s), 18.2MiB/s-18.2MiB/s (19.1MB/s-19.1MB/s), io=647MiB (678MB), run=35492-35492msec
WRITE: bw=12.6MiB/s (13.3MB/s), 12.6MiB/s-12.6MiB/s (13.3MB/s-13.3MB/s), io=1024MiB (1074MB), run=80995-80995msec

Disk stats (read/write):
loop9: ios=164728/275088, merge=0/522, ticks=561877/1343351, in_queue=1912902, util=99.83%
+ df -h /mnt/loop1 /mnt/loop10 /mnt/loop2 /mnt/loop3 /mnt/loop4 /mnt/loop5 /mnt/loop6 /mnt/loop7 /mnt/loop8 /mnt/loop9

Filesystem      Size  Used Avail Use% Mounted on
/dev/loop1      2.0G  1.1G  965M  53% /mnt/loop1
/dev/loop10     2.0G  1.1G  966M  53% /mnt/loop10
/dev/loop2      2.0G  1.1G  966M  53% /mnt/loop2
/dev/loop3      2.0G  1.1G  965M  53% /mnt/loop3
/dev/loop4      2.0G  1.1G  965M  53% /mnt/loop4
/dev/loop5      2.0G  1.1G  965M  53% /mnt/loop5
/dev/loop6      2.0G  1.1G  965M  53% /mnt/loop6
/dev/loop7      2.0G  1.1G  965M  53% /mnt/loop7
/dev/loop8      2.0G  1.1G  965M  53% /mnt/loop8
/dev/loop9      2.0G  1.1G  965M  53% /mnt/loop9

+ unload_loop
++ shuf -i 1-10 -n 10
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop2
+ rm -fr ./loop2
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop6
+ rm -fr ./loop6
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop3
+ rm -fr ./loop3
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop5
+ rm -fr ./loop5
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop4
+ rm -fr ./loop4
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop7
+ rm -fr ./loop7
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop1
+ rm -fr ./loop1
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop9
+ rm -fr ./loop9
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop10
+ rm -fr ./loop10
+ for i in shuf -i 1-$NN -n $NN
+ umount /mnt/loop8
+ rm -fr ./loop8
+ losetup -D
+ sleep 3
+ rmmod loop
+ modprobe -r loop
+ lsmod
+ grep loop
++ shuf -i 1-10 -n 10
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop5
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop7
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop10
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop1
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop6
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop8
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop2
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop3
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop9
+ for i in shuf -i 1-$NN -n $NN
+ rm -fr ./loop4
+ rm -fr /mnt/loop1 /mnt/loop10 /mnt/loop2 /mnt/loop3 /mnt/loop4 /mnt/loop5 /mnt/loop6 /mnt/loop7 /mnt/loop8 /mnt/loop9
+ dmesg -c

[ 2444.772430] XFS (loop2): Unmounting Filesystem
[ 2444.920447] XFS (loop6): Unmounting Filesystem
[ 2445.057306] XFS (loop3): Unmounting Filesystem
[ 2445.197380] XFS (loop5): Unmounting Filesystem
[ 2445.357324] XFS (loop4): Unmounting Filesystem
[ 2445.483461] XFS (loop7): Unmounting Filesystem
[ 2445.623297] XFS (loop1): Unmounting Filesystem
[ 2445.765312] XFS (loop9): Unmounting Filesystem
[ 2446.024364] XFS (loop10): Unmounting Filesystem
[ 2446.194357] XFS (loop8): Unmounting Filesystem

Signature · 1 line

2.29.0

Chaitanya Kulkarni

author

2022-02-15 11:51 UTC #1 lore raw

PATCH v2 1/4 loop: use sysfs_emit() in the sysfs xxx show()

sprintf does not know the PAGE_SIZE maximum of the temporary buffer used for outputting sysfs content and it's possible to overrun the PAGE_SIZE buffer length.

Use a generic sysfs_emit function that knows the size of the temporary buffer and ensures that no overrun is done for offset attribute in loop_attr_[offset|sizelimit|autoclear|partscan|dio]_show() callbacks.

Signed-off-by Chaitanya Kulkarni <[email protected]>

Reviewed-by Himanshu Madhani <[email protected]>

---
 drivers/block/loop.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

drivers/block/loop.c +5 -5

index bdea448d2419..a55e5eda1d17 100644
@@ -680,33 +680,33 @@ static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf)
 
 static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf)
 {
-	return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_offset);
+	return sysfs_emit(buf, "%llu\n", (unsigned long long)lo->lo_offset);
 }
 
 static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf)
 {
-	return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit);
+	return sysfs_emit(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit);
 }
 
 static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf)
 {
 	int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR);
 
-	return sprintf(buf, "%s\n", autoclear ? "1" : "0");
+	return sysfs_emit(buf, "%s\n", autoclear ? "1" : "0");
 }
 
 static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf)
 {
 	int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN);
 
-	return sprintf(buf, "%s\n", partscan ? "1" : "0");
+	return sysfs_emit(buf, "%s\n", partscan ? "1" : "0");
 }
 
 static ssize_t loop_attr_dio_show(struct loop_device *lo, char *buf)
 {
 	int dio = (lo->lo_flags & LO_FLAGS_DIRECT_IO);
 
-	return sprintf(buf, "%s\n", dio ? "1" : "0");
+	return sysfs_emit(buf, "%s\n", dio ? "1" : "0");
 }
 
 LOOP_ATTR_RO(backing_file);

Signature · 1 line

2.29.0

Chaitanya Kulkarni

author

2022-02-15 11:51 UTC #2 lore raw

PATCH v2 2/4 loop: remove extra variable in lo_fallocate()

In reply to Chaitanya Kulkarni

The local variable q is used to pass it to the blk_queue_discard(). We can get away with using lo->lo_queue instead of storing in a local variable which is not used anywhere else.

No functional change in this patch.

Signed-off-by Chaitanya Kulkarni <[email protected]>

Reviewed-by Himanshu Madhani <[email protected]>

---
 drivers/block/loop.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

drivers/block/loop.c +1 -2

index a55e5eda1d17..77c61eaaa6e4 100644
@@ -308,12 +308,11 @@ static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
 	 * a.k.a. discard/zerorange.
 	 */
 	struct file *file = lo->lo_backing_file;
-	struct request_queue *q = lo->lo_queue;
 	int ret;
 
 	mode |= FALLOC_FL_KEEP_SIZE;
 
-	if (!blk_queue_discard(q)) {
+	if (!blk_queue_discard(lo->lo_queue)) {
 		ret = -EOPNOTSUPP;
 		goto out;
 	}

Signature · 1 line

2.29.0

Chaitanya Kulkarni

author

2022-02-15 11:52 UTC #3 lore raw

PATCH v2 3/4 loop: remove extra variable in lo_req_flush

In reply to Chaitanya Kulkarni

The local variable file is used to pass it to the vfs_fsync(). We can get away with using lo->lo_backing_file instead of storing in a local variable which is not used anywhere else.

No functional change in this patch.

Signed-off-by Chaitanya Kulkarni <[email protected]>

Reviewed-by Himanshu Madhani <[email protected]>

---
 drivers/block/loop.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

drivers/block/loop.c +1 -2

index 77c61eaaa6e4..18b30a56bfc4 100644
@@ -326,8 +326,7 @@ static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
 
 static int lo_req_flush(struct loop_device *lo, struct request *rq)
 {
-	struct file *file = lo->lo_backing_file;
-	int ret = vfs_fsync(file, 0);
+	int ret = vfs_fsync(lo->lo_backing_file, 0);
 	if (unlikely(ret && ret != -EINVAL))
 		ret = -EIO;

Signature · 1 line

2.29.0

Chaitanya Kulkarni

author

2022-02-15 11:52 UTC #4 lore raw

PATCH v2 4/4 loop: allow user to set the queue depth

In reply to Chaitanya Kulkarni

Instead of hardcoding queue depth allow user to set the hw queue depth using module parameter. Set default value to 128 to retain the existing behavior.

Signed-off-by Chaitanya Kulkarni <[email protected]>

Reviewed-by Himanshu Madhani <[email protected]>

---
 drivers/block/loop.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

drivers/block/loop.c +4 -1

index 18b30a56bfc4..fd2184d63c11 100644
@@ -1785,6 +1785,9 @@ module_param(max_loop, int, 0444);
 MODULE_PARM_DESC(max_loop, "Maximum number of loop devices");
 module_param(max_part, int, 0444);
 MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device");
+static int hw_queue_depth = 128;
+module_param_named(hw_queue_depth, hw_queue_depth, int, 0444);
+MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 128");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR);

@@ -1979,7 +1982,7 @@ static int loop_add(int i)
 
 	lo->tag_set.ops = &loop_mq_ops;
 	lo->tag_set.nr_hw_queues = 1;
-	lo->tag_set.queue_depth = 128;
+	lo->tag_set.queue_depth = hw_queue_depth;
 	lo->tag_set.numa_node = NUMA_NO_NODE;
 	lo->tag_set.cmd_size = sizeof(struct loop_cmd);
 	lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING |

Signature · 1 line

2.29.0

Jens Axboe

maintainer

2022-02-15 14:54 UTC #5 lore raw

Re: [PATCH V2 4/4] loop: allow user to set the queue depth

Quoted 3 lines · Chaitanya Kulkarni

Instead of hardcoding queue depth allow user to set the hw queue depth using module parameter. Set default value to 128 to retain the existing behavior.

Do we want to ensure that the depth falls within a reasonable range? I guess we don't if we just ensure that it fails gracefully. Eg have you tried the usual sanity checks of -1, 0, 1, huge?

Signature · 1 line

Jens Axboe

Chaitanya Kulkarni

2022-02-15 16:54 UTC #6 lore raw

Re: [PATCH V2 4/4] loop: allow user to set the queue depth

Quoted 9 lines · Jens Axboe

Quoted 3 lines · Chaitanya Kulkarni
Instead of hardcoding queue depth allow user to set the hw queue depth using module parameter. Set default value to 128 to retain the existing behavior.
Do we want to ensure that the depth falls within a reasonable range? I guess we don't if we just ensure that it fails gracefully. Eg have you tried the usual sanity checks of -1, 0, 1, huge?

Yes we should, we can error out for values < 1 see [1], but what should be the reasonable range for any positive or huge values ? since block layer will reduce the depth if it cannot incorporate huge values to the ones which it can in blk_mq_alloc_set_map_and_rqs().

[1] loop hw_queue_depth parameter validation incremental patch untested :-

root@dev linux-block (for-next) # git diff

drivers/block/loop.c +1 -0

index fd2184d63c11..c9a732a22767 100644
@@ -85,6 +85,7 @@
  #include <linux/uaccess.h>
 
  #define LOOP_IDLE_WORKER_TIMEOUT (60 * HZ)
+#define LOOP_DEFAULT_HW_Q_DEPTH (128)
 
  static DEFINE_IDR(loop_index_idr);
  static DEFINE_MUTEX(loop_ctl_mutex);

@@ -1785,9 +1786,24 @@ module_param(max_loop, int, 0444);
  MODULE_PARM_DESC(max_loop, "Maximum number of loop devices");
  module_param(max_part, int, 0444);
  MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop

device");
-static int hw_queue_depth = 128; -module_param_named(hw_queue_depth, hw_queue_depth, int, 0444); +
+static int hw_queue_depth = LOOP_DEFAULT_HW_Q_DEPTH;
+
+static int loop_set_hw_queue_depth(const char *s, const struct kernel_param *p)
+{
+ int ret = kstrtoint(s, 10, &hw_queue_depth);
+
+ return (ret || (hw_queue_depth < 1) ? -EINVAL : 0;
+}
+
+static const struct kernel_param_ops loop_hw_qdepth_param_ops = {

+       .set    = loop_set_hw_queue_depth,
+       .get    = param_get_int,

+};
+
+device_param_cb(hw_queue_depth, &loop_hw_qdepth_param_ops, &hw_queue_depth, 0444);
MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue.
Default: 128");
+

-ck