[PATCH] loop: Fix wrong masking of status flags

From: Martijn Coenen
Date: Thu Jun 04 2020 - 16:25:35 EST


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@xxxxxxxxxxx>
---
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