On 3/16/21 2:56 PM, Song Liu wrote:
On Mar 15, 2021, at 7:29 PM, Xiao Ni <xni@xxxxxxxxxx> wrote:
Hi all
The atomic_t r10_bio->remaining starts at 1 in raid10_handle_discard. It means
raid10_handle_discard uses it and sets it to 1. So in fact it starts at 0 and sets to 1
when it's used at first time. Then r10_bio->remaining is added by atomic_inc per usage.
It decrements the value when leaving raid10_handle_discard and in every callback function.
So the count of r10_bio->remaining in this patch is right.
Regards
Xiao
It does look like a false alarm, as we set r10bio to first_r10bio after
the free.
Thanks,
Song
Hi all,
Thanks for the clarification, we have disabled such warning.
Best Regards,
Rong Chen
On 03/16/2021 08:29 AM, kernel test robot wrote:
tree: git://git.kernel.org/pub/scm/linux/kernel/git/song/md.git md-next
head: 49c4d345c81f149a29b3db6e521e5191e55f02b6
commit: f3cf8c2b2caf6ae77b7c786218d3b060faef63a6 [5/6] md/raid10: improve discard request for far layout
config: x86_64-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
"coccinelle warnings: (new ones prefixed by >>)"
drivers/md/raid10.c:1526:8-27: atomic_dec_and_test variation before object free at line 1532.
drivers/md/raid10.c:1526:8-27: atomic_dec_and_test variation before object free at line 1537.
vim +1526 drivers/md/raid10.c
1520
1521 static void raid_end_discard_bio(struct r10bio *r10bio)
1522 {
1523 struct r10conf *conf = r10bio->mddev->private;
1524 struct r10bio *first_r10bio;
1525
1526 while (atomic_dec_and_test(&r10bio->remaining)) {
1527
1528 allow_barrier(conf);
1529
1530 if (!test_bit(R10BIO_Discard, &r10bio->state)) {
1531 first_r10bio = (struct r10bio *)r10bio->master_bio;
1532 free_r10bio(r10bio);
1533 r10bio = first_r10bio;
1534 } else {
1535 md_write_end(r10bio->mddev);
1536 bio_endio(r10bio->master_bio);
1537 free_r10bio(r10bio);
1538 break;
1539 }
1540 }
1541 }
1542
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
_______________________________________________
kbuild-all mailing list -- kbuild-all@xxxxxxxxxxxx
To unsubscribe send an email to kbuild-all-leave@xxxxxxxxxxxx
