Commit e99c79a6 authored Jun 04, 2020 by Martijn Coenen

BACKPORT: loop: Fix wrong masking of status flags



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")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Martijn Coenen <maco@android.com>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 6ac92fb5cdff6e5708199f1d5d9d58011ccc76a0)
Bug: 148607611
Change-Id: I2bc249ad0e0b33b7d1f4e8ae994667727574d2d5

parent cf69c366

drivers/block/loop.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1230,7 +1230,7 @@ loop_set_status(struct loop_device lo, const struct loop_info64 info)
		goto exit;

		/* 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 */