| Message ID | 20191001074839.1994-1-damien.lemoal@wdc.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 8f8fed0cdbbd6cdbf28d9ebe662f45765d2f7d39 |
| Headers | show |
| Series | [V3] scsi: save/restore command resid for error handling | expand |
On 10/1/19 12:48 AM, Damien Le Moal wrote: > When a non-passthrough command is terminated with CHECK CONDITION, > request sense is executed by hijacking the command descriptor. Since > scsi_eh_prep_cmnd() and scsi_eh_restore_cmnd() do not save/restore the > original command resid, the value returned on failure of the original > command is lost and replaced with the value set by the execution of the > request sense command. This value may in many instances be unaligned to > the device sector size, causing sd_done() to print a warning message > about the incorrect unaligned resid before the command is retried. > > Fix this problem by saving the original command residual in struct > scsi_eh_save using scsi_eh_prep_cmnd() and restoring it in > scsi_eh_restore_cmnd(). In addition, to make sure that the request sense > command is executed with a correctly initialized command structure, also > reset the residual to 0 in scsi_eh_prep_cmnd() after saving the original > command value in struct scsi_eh_save. Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Damien, > When a non-passthrough command is terminated with CHECK CONDITION, > request sense is executed by hijacking the command descriptor. [...] Applied to 5.4/scsi-fixes. Thanks for debugging this issue!
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 1c470e31ae81..ae2fa170f6ad 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -967,6 +967,7 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses, ses->data_direction = scmd->sc_data_direction; ses->sdb = scmd->sdb; ses->result = scmd->result; + ses->resid_len = scmd->req.resid_len; ses->underflow = scmd->underflow; ses->prot_op = scmd->prot_op; ses->eh_eflags = scmd->eh_eflags; @@ -977,6 +978,7 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses, memset(scmd->cmnd, 0, BLK_MAX_CDB); memset(&scmd->sdb, 0, sizeof(scmd->sdb)); scmd->result = 0; + scmd->req.resid_len = 0; if (sense_bytes) { scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE, @@ -1029,6 +1031,7 @@ void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses) scmd->sc_data_direction = ses->data_direction; scmd->sdb = ses->sdb; scmd->result = ses->result; + scmd->req.resid_len = ses->resid_len; scmd->underflow = ses->underflow; scmd->prot_op = ses->prot_op; scmd->eh_eflags = ses->eh_eflags; diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h index 3810b340551c..6bd5ed695a5e 100644 --- a/include/scsi/scsi_eh.h +++ b/include/scsi/scsi_eh.h @@ -32,6 +32,7 @@ extern int scsi_ioctl_reset(struct scsi_device *, int __user *); struct scsi_eh_save { /* saved state */ int result; + unsigned int resid_len; int eh_eflags; enum dma_data_direction data_direction; unsigned underflow;
When a non-passthrough command is terminated with CHECK CONDITION, request sense is executed by hijacking the command descriptor. Since scsi_eh_prep_cmnd() and scsi_eh_restore_cmnd() do not save/restore the original command resid, the value returned on failure of the original command is lost and replaced with the value set by the execution of the request sense command. This value may in many instances be unaligned to the device sector size, causing sd_done() to print a warning message about the incorrect unaligned resid before the command is retried. Fix this problem by saving the original command residual in struct scsi_eh_save using scsi_eh_prep_cmnd() and restoring it in scsi_eh_restore_cmnd(). In addition, to make sure that the request sense command is executed with a correctly initialized command structure, also reset the residual to 0 in scsi_eh_prep_cmnd() after saving the original command value in struct scsi_eh_save. Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> --- Changes from V2: * Open code resid save/restore to keep the functions style * rename struct scsi_eh_save resid field to resid_len to match struct scsi_request field name Changes from V1: * Dropped patch 2 * Add resid reset in scsi_eh_prep_cmnd() drivers/scsi/scsi_error.c | 3 +++ include/scsi/scsi_eh.h | 1 + 2 files changed, 4 insertions(+)