On Sun, 2018-04-08 at 12:02 -0400, Wakko Warner wrote:
> I finished with git bisect. Here's the output:
> 84c8590646d5b35804bac60eb58b145839b5893e is the first bad commit
> commit 84c8590646d5b35804bac60eb58b145839b5893e
> Author: Ming Lei <tom.leiming@xxxxxxxxx>
> Date: Fri Nov 11 20:05:32 2016 +0800
>
> target: avoid accessing .bi_vcnt directly
>
> When the bio is full, bio_add_pc_page() will return zero,
> so use this information tell when the bio is full.
>
> Also replace access to .bi_vcnt for pr_debug() with bio_segments().
>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
> Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
> Signed-off-by: Jens Axboe <axboe@xxxxxx>
>
> :040000 040000 a3ebbb71c52ee4eb8c3be4d033b81179211bf704 de39a328dbd1b18519946b3ad46d9302886e0dd0 M drivers
>
> I did a diff between HEAD^ and HEAD and manually patched the file from
> 4.15.14. It's not an exact revert. I'm running it now and it's working.
> I'll do a better test later on. Here's the patch:
>
> --- a/drivers/target/target_core_pscsi.c 2018-02-04 14:31:31.077316617 -0500
> +++ b/drivers/target/target_core_pscsi.c 2018-04-08 11:43:49.588641374 -0400
> @@ -915,7 +915,9 @@
> bio, page, bytes, off);
> pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
> bio_segments(bio), nr_vecs);
> - if (rc != bytes) {
> + if (rc != bytes)
> + goto fail;
> + if (bio->bi_vcnt > nr_vecs) {
> pr_debug("PSCSI: Reached bio->bi_vcnt max:"
> " %d i: %d bio: %p, allocating another"
> " bio\n", bio->bi_vcnt, i, bio);
Hello Ming,
Can you have a look at this? The start of this e-mail thread is available at
https://www.mail-archive.com/linux-scsi@xxxxxxxxxxxxxxx/msg72574.html.
Thanks,
Bart.
