mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-25 03:46:17 +00:00
Code Issues Releases Wiki Activity

scsi: core: Increase scsi_device's iodone_cnt in scsi_timeout()

Browse source 
If a SCSI command times out and is going to be aborted, we should increase
the iodone_cnt of the related scsi_device. Otherwise the iodone_cnt would
be smaller than iorequest_cnt.

Increasing iodone_cnt in scsi_timeout() would not cause a double accounting
issue. Brief analysis follows:

 - We add the iodone_cnt when BLK_EH_DONE is returned in
   scsi_timeout(). The related command's timeout event would not happen.

 - If the abort succeeds and the command is not retried, the command would
   be completed with scsi_finish_command() which would not increase
   iodone_cnt.

 - If the abort succeeds and the command is retried, it would be requeue. A
   scsi_dispatch_cmd() would be called and iorequest_cnt would be increased
   again.

 - If the abort fails, the error handler successfully recovers the device,
   and the command is not retried, the command would be completed with
   scsi_finish_command() which would not increase iodone_cnt.

 - If the abort fails, the error handler successfully recovers the device,
   and the command is retried, the iorequest_cnt would be increased again.

Signed-off-by: Wenchao Hao <haowenchao@huawei.com>
Link: https://lore.kernel.org/r/20221123122137.150776-2-haowenchao@huawei.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Wenchao Hao 2022-11-23 20:21:36 +08:00 committed by Martin K. Petersen
parent 0c26a2d7c9
commit ec9780e48c
1 changed files with 1 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
drivers/scsi/scsi_error.c
View file

@ -354,6 +354,7 @@ enum blk_eh_timer_return scsi_timeout(struct request *req)
*/
if (test_and_set_bit(SCMD_STATE_COMPLETE, &scmd->state))
return BLK_EH_DONE;
atomic_inc(&scmd->device->iodone_cnt);
if (scsi_abort_command(scmd) != SUCCESS) {
set_host_byte(scmd, DID_TIME_OUT);
scsi_eh_scmd_add(scmd);