Bart Van Assche wrote: > On Sat, 2018-04-07 at 12:53 -0400, Wakko Warner wrote: > > Bart Van Assche wrote: > > > On Thu, 2018-04-05 at 22:06 -0400, Wakko Warner wrote: > > > > I know now why scsi_print_command isn't doing anything. cmd->cmnd is null. > > > > I added a dev_printk in scsi_print_command where the 2 if statements return. > > > > Logs: > > > > [ 29.866415] sr 3:0:0:0: cmd->cmnd is NULL > > > > > > That's something that should never happen. As one can see in > > > scsi_setup_scsi_cmnd() and scsi_setup_fs_cmnd() both functions initialize > > > that pointer. Since I have not yet been able to reproduce myself what you > > > reported, would it be possible for you to bisect this issue? You will need > > > to follow something like the following procedure (see also > > > https://git-scm.com/docs/git-bisect): > > > > After doing 3 successful compiles with good/bad, I got this error and was > > not able to compile any more kernels: > > CC scripts/mod/devicetable-offsets.s > > scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode > > /* empty file to figure out endianness / word size */ > > > > scripts/mod/devicetable-offsets.c:1:0: error: code model kernel does not support PIC mode > > #include <linux/kbuild.h> > > > > scripts/Makefile.build:153: recipe for target 'scripts/mod/devicetable-offsets.s' failed > > > > I don't think it found the bad commit. > > Have you tried to modify the kernel Makefile as indicated in the following > e-mail? This should make the kernel build: > > https://lists.ubuntu.com/archives/kernel-team/2016-May/077178.html Thanks. That helped. 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); I really appreciate your time and assistance with this. -- Microsoft has beaten Volkswagen's world record. Volkswagen only created 22 million bugs.
