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): I don't know how relevent it is, but this machine boots nfs and exports it's dvd drives over iscsi with the target modules. My scsi_target.lio is at the end. I removed the iqn name. The options are default except for a few. Non default options I tabbed over. eth0 is the nfs/localnet nic and eth1 is the nic that iscsi goes over. eth0 is onboard pci 8086:1502 (subsystem 1028:05d3) eth1 is pci 8086:107d (subsystem 8086:1084) Both use the e1000e driver The initiator is running 4.4.107. When running on the initiator, /dev/sr1 is the target /dev/sr0. Therefor cat /dev/sr1 > /dev/null seems to work. mount /dev/sr1 /cdrom works find /cdrom -type f | xargs cat > /dev/null immediately crashes the target. Burning to /dev/sr1 seems to work. I have another nic that uses igb instead, I'll see if that makes a difference. > git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > git bisect start > git bisect bad v4.10 > git bisect good v4.9 > > and then build the kernel, install it, boot the kernel and test it. > Depending on the result, run either git bisect bad or git bisect good and > keep going until git bisect comes to a conclusion. This can take an hour or > more. I'll try this. Here's my scsi_target.lio: storage pscsi { disk dvd0 { path /dev/sr0 attribute { emulate_3pc yes emulate_caw yes emulate_dpo no emulate_fua_read no emulate_model_alias no emulate_rest_reord no emulate_tas yes emulate_tpu no emulate_tpws no emulate_ua_intlck_ctrl no emulate_write_cache no enforce_pr_isids yes fabric_max_sectors 8192 is_nonrot yes max_unmap_block_desc_count 0 max_unmap_lba_count 0 max_write_same_len 65535 queue_depth 128 unmap_granularity 0 unmap_granularity_alignment 0 } } disk dvd1 { path /dev/sr1 attribute { emulate_3pc yes emulate_caw yes emulate_dpo no emulate_fua_read no emulate_model_alias no emulate_rest_reord no emulate_tas yes emulate_tpu no emulate_tpws no emulate_ua_intlck_ctrl no emulate_write_cache no enforce_pr_isids yes fabric_max_sectors 8192 is_nonrot yes max_unmap_block_desc_count 0 max_unmap_lba_count 0 max_write_same_len 65535 queue_depth 128 unmap_granularity 0 unmap_granularity_alignment 0 } } disk dvd2 { path /dev/sr2 attribute { emulate_3pc yes emulate_caw yes emulate_dpo no emulate_fua_read no emulate_model_alias no emulate_rest_reord no emulate_tas yes emulate_tpu no emulate_tpws no emulate_ua_intlck_ctrl no emulate_write_cache no enforce_pr_isids yes fabric_max_sectors 8192 is_nonrot yes max_unmap_block_desc_count 0 max_unmap_lba_count 0 max_write_same_len 65535 queue_depth 128 unmap_granularity 0 unmap_granularity_alignment 0 } } } fabric iscsi { discovery_auth { enable no mutual_password "" mutual_userid "" password "" userid "" } target iqn.<myiqn>:dvd tpgt 1 { enable yes attribute { authentication no cache_dynamic_acls yes default_cmdsn_depth 64 default_erl 0 demo_mode_discovery yes demo_mode_write_protect no fabric_prot_type 0 generate_node_acls yes login_timeout 15 netif_timeout 2 prod_mode_write_protect no t10_pi 0 tpg_enabled_sendtargets 1 } auth { password "" password_mutual "" userid "" userid_mutual "" } parameter { AuthMethod "CHAP,None" DataDigest "CRC32C,None" DataPDUInOrder yes DataSequenceInOrder yes DefaultTime2Retain 20 DefaultTime2Wait 2 ErrorRecoveryLevel no FirstBurstLength 65536 HeaderDigest "CRC32C,None" IFMarkInt Reject IFMarker no ImmediateData yes InitialR2T yes MaxBurstLength 262144 MaxConnections 1 MaxOutstandingR2T 1 MaxRecvDataSegmentLength 8192 MaxXmitDataSegmentLength 262144 OFMarkInt Reject OFMarker no TargetAlias "LIO Target" } lun 0 backend pscsi:dvd0 lun 1 backend pscsi:dvd1 lun 2 backend pscsi:dvd2 portal 0.0.0.0:3260 } } -- Microsoft has beaten Volkswagen's world record. Volkswagen only created 22 million bugs.