[PATCH] loop: Fix wrong masking of status flags

[PATCH] loop: Fix wrong masking of status flags

[Martijn Coenen]

In faf1d25440d6, loop_set_status() now assigns lo_status directly from
the passed in lo_flags, but then fixes it up by masking out flags that
can't be set by LOOP_SET_STATUS; unfortunately the mask was negated.

Re-ran all ltp ioctl_loop tests, and they all passed.

Pass run of the previously failing one:

tst_test.c:1247: INFO: Timeout per run is 0h 05m 00s
tst_device.c:88: INFO: Found free device 0 '/dev/loop0'
ioctl_loop01.c:49: PASS: /sys/block/loop0/loop/partscan = 0
ioctl_loop01.c:50: PASS: /sys/block/loop0/loop/autoclear = 0
ioctl_loop01.c:51: PASS: /sys/block/loop0/loop/backing_file =
'/tmp/ZRJ6H4/test.img'
ioctl_loop01.c:65: PASS: get expected lo_flag 12
ioctl_loop01.c:67: PASS: /sys/block/loop0/loop/partscan = 1
ioctl_loop01.c:68: PASS: /sys/block/loop0/loop/autoclear = 1
ioctl_loop01.c:77: PASS: access /dev/loop0p1 succeeds
ioctl_loop01.c:83: PASS: access /sys/block/loop0/loop0p1 succeeds

Summary:
passed   8
failed   0
skipped  0
warnings 0

Fixes: faf1d25440d6 ("loop: Clean up LOOP_SET_STATUS lo_flags handling")
Signed-off-by: Martijn Coenen <maco@android.com>
---
 drivers/block/loop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 4212288ab157..ad63e4247868 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1390,7 +1390,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
 		goto out_unfreeze;
 
 	/* Mask out flags that can't be set using LOOP_SET_STATUS. */
-	lo->lo_flags &= ~LOOP_SET_STATUS_SETTABLE_FLAGS;
+	lo->lo_flags &= LOOP_SET_STATUS_SETTABLE_FLAGS;
 	/* For those flags, use the previous values instead */
 	lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_SETTABLE_FLAGS;
 	/* For flags that can't be cleared, use previous values too */
-- 
2.27.0.278.ge193c7cf3a9-goog

Re: [PATCH] loop: Fix wrong masking of status flags

[Naresh Kamboju]

On Fri, 5 Jun 2020 at 01:55, Martijn Coenen <maco@android.com> wrote:
>
> In faf1d25440d6, loop_set_status() now assigns lo_status directly from
> the passed in lo_flags, but then fixes it up by masking out flags that
> can't be set by LOOP_SET_STATUS; unfortunately the mask was negated.
>
> Re-ran all ltp ioctl_loop tests, and they all passed.
>
> Pass run of the previously failing one:
>
> tst_test.c:1247: INFO: Timeout per run is 0h 05m 00s
> tst_device.c:88: INFO: Found free device 0 '/dev/loop0'
> ioctl_loop01.c:49: PASS: /sys/block/loop0/loop/partscan = 0
> ioctl_loop01.c:50: PASS: /sys/block/loop0/loop/autoclear = 0
> ioctl_loop01.c:51: PASS: /sys/block/loop0/loop/backing_file =
> '/tmp/ZRJ6H4/test.img'
> ioctl_loop01.c:65: PASS: get expected lo_flag 12
> ioctl_loop01.c:67: PASS: /sys/block/loop0/loop/partscan = 1
> ioctl_loop01.c:68: PASS: /sys/block/loop0/loop/autoclear = 1
> ioctl_loop01.c:77: PASS: access /dev/loop0p1 succeeds
> ioctl_loop01.c:83: PASS: access /sys/block/loop0/loop0p1 succeeds
>
> Summary:
> passed   8
> failed   0
> skipped  0
> warnings 0
>
> Fixes: faf1d25440d6 ("loop: Clean up LOOP_SET_STATUS lo_flags handling")
> Signed-off-by: Martijn Coenen <maco@android.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>

Thanks for the quick fix patch.
I have tested with the patch applied on x86 and arm64
and confirm it fixes the reported problem [1].

Test log link,
https://lkft.validation.linaro.org/scheduler/job/1471435#L1299
https://lkft.validation.linaro.org/scheduler/job/1471574#L714

ref:
https://lore.kernel.org/linux-block/CAB0TPYEx4Z8do3qL1KVpnGGnorTLGqKtrwi1uQgxQ6Xw3JqiYw@mail.gmail.com/T/#t

- Naresh

Re: [PATCH] loop: Fix wrong masking of status flags

[Jens Axboe]

On 6/4/20 2:25 PM, Martijn Coenen wrote:
> In faf1d25440d6, loop_set_status() now assigns lo_status directly from
> the passed in lo_flags, but then fixes it up by masking out flags that
> can't be set by LOOP_SET_STATUS; unfortunately the mask was negated.
> 
> Re-ran all ltp ioctl_loop tests, and they all passed.
> 
> Pass run of the previously failing one:
> 
> tst_test.c:1247: INFO: Timeout per run is 0h 05m 00s
> tst_device.c:88: INFO: Found free device 0 '/dev/loop0'
> ioctl_loop01.c:49: PASS: /sys/block/loop0/loop/partscan = 0
> ioctl_loop01.c:50: PASS: /sys/block/loop0/loop/autoclear = 0
> ioctl_loop01.c:51: PASS: /sys/block/loop0/loop/backing_file =
> '/tmp/ZRJ6H4/test.img'
> ioctl_loop01.c:65: PASS: get expected lo_flag 12
> ioctl_loop01.c:67: PASS: /sys/block/loop0/loop/partscan = 1
> ioctl_loop01.c:68: PASS: /sys/block/loop0/loop/autoclear = 1
> ioctl_loop01.c:77: PASS: access /dev/loop0p1 succeeds
> ioctl_loop01.c:83: PASS: access /sys/block/loop0/loop0p1 succeeds
> 
> Summary:
> passed   8
> failed   0
> skipped  0
> warnings 0

Applied, thanks.

-- 
Jens Axboe