On 10/22/21 10:58, Shinichiro Kawasaki wrote:
Hello Pavel,
Recently I tried out for-next branch and observed that simple dd command to
zonefs files causes an I/O error.
$ sudo dd if=/dev/zero of=/mnt/seq/0 bs=4096 count=1 oflag=direct
dd: error writing '/mnt/seq/0': Input/output error
1+0 records in
0+0 records out
0 bytes copied, 0.00409641 s, 0.0 kB/s
At that time, kernel reported warnings.
[90713.298721][ T2735] zonefs (nvme0n1) WARNING: inode 1: invalid size 0 (should be 4096)
[90713.299761][ T2735] zonefs (nvme0n1) WARNING: remounting filesystem read-only
I bisected and found that this patch triggers the error and warnings. I think
one liner change is needed in this patch. Please find it below, in line.
[...]
- if (req_op(rq) == REQ_OP_ZONE_APPEND && error == BLK_STS_OK) {
+ } else if (req_op(rq) == REQ_OP_ZONE_APPEND) {
/*
* Partial zone append completions cannot be supported as the
* BIO fragments may end up not being written sequentially.
*/
- if (bio->bi_iter.bi_size)
+ if (bio->bi_iter.bi_size == nbytes)
I think the line above should be,
if (bio->bi_iter.bi_size != nbytes)
You're right, that was a stupid mistake, thanks!
Jens, will you fold it in or would you prefer a patch?
Before applying the patch, the if statement checked "bi_size is not zero".
After applying the patch, bio_advance(bio, nbytes) moved after this check.
Then bi_size is not decremented by nbytes and the check should be "bi_size is
not nbytes". With this modification, the I/O error and the warnings go away.
bio->bi_status = BLK_STS_IOERR;
else
bio->bi_iter.bi_sector = rq->__sector;
}
+ bio_advance(bio, nbytes);
+
+ if (unlikely(rq->rq_flags & RQF_QUIET))
+ bio_set_flag(bio, BIO_QUIET);
/* don't actually finish bio if it's part of flush sequence */
if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ))
bio_endio(bio);
--
2.33.1
--
Pavel Begunkov
