diff options
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 98 | ||||
| -rw-r--r-- | include/scsi/scsi_device.h | 48 |
2 files changed, 143 insertions, 3 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index cf3864f72093..16a33a558842 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -184,6 +184,92 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) __scsi_queue_insert(cmd, reason, true); } +void scsi_failures_reset_retries(struct scsi_failures *failures) +{ + struct scsi_failure *failure; + + failures->total_retries = 0; + + for (failure = failures->failure_definitions; failure->result; + failure++) + failure->retries = 0; +} +EXPORT_SYMBOL_GPL(scsi_failures_reset_retries); + +/** + * scsi_check_passthrough - Determine if passthrough scsi_cmnd needs a retry. + * @scmd: scsi_cmnd to check. + * @failures: scsi_failures struct that lists failures to check for. + * + * Returns -EAGAIN if the caller should retry else 0. + */ +static int scsi_check_passthrough(struct scsi_cmnd *scmd, + struct scsi_failures *failures) +{ + struct scsi_failure *failure; + struct scsi_sense_hdr sshdr; + enum sam_status status; + + if (!failures) + return 0; + + for (failure = failures->failure_definitions; failure->result; + failure++) { + if (failure->result == SCMD_FAILURE_RESULT_ANY) + goto maybe_retry; + + if (host_byte(scmd->result) && + host_byte(scmd->result) == host_byte(failure->result)) + goto maybe_retry; + + status = status_byte(scmd->result); + if (!status) + continue; + + if (failure->result == SCMD_FAILURE_STAT_ANY && + !scsi_status_is_good(scmd->result)) + goto maybe_retry; + + if (status != status_byte(failure->result)) + continue; + + if (status_byte(failure->result) != SAM_STAT_CHECK_CONDITION || + failure->sense == SCMD_FAILURE_SENSE_ANY) + goto maybe_retry; + + if (!scsi_command_normalize_sense(scmd, &sshdr)) + return 0; + + if (failure->sense != sshdr.sense_key) + continue; + + if (failure->asc == SCMD_FAILURE_ASC_ANY) + goto maybe_retry; + + if (failure->asc != sshdr.asc) + continue; + + if (failure->ascq == SCMD_FAILURE_ASCQ_ANY || + failure->ascq == sshdr.ascq) + goto maybe_retry; + } + + return 0; + +maybe_retry: + if (failure->allowed) { + if (failure->allowed == SCMD_FAILURE_NO_LIMIT || + ++failure->retries <= failure->allowed) + return -EAGAIN; + } else { + if (failures->total_allowed == SCMD_FAILURE_NO_LIMIT || + ++failures->total_retries <= failures->total_allowed) + return -EAGAIN; + } + + return 0; +} + /** * scsi_execute_cmd - insert request and wait for the result * @sdev: scsi_device @@ -192,7 +278,7 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) * @buffer: data buffer * @bufflen: len of buffer * @timeout: request timeout in HZ - * @retries: number of times to retry request + * @ml_retries: number of times SCSI midlayer will retry request * @args: Optional args. See struct definition for field descriptions * * Returns the scsi_cmnd result field if a command was executed, or a negative @@ -200,7 +286,7 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) */ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd, blk_opf_t opf, void *buffer, unsigned int bufflen, - int timeout, int retries, + int timeout, int ml_retries, const struct scsi_exec_args *args) { static const struct scsi_exec_args default_args; @@ -214,6 +300,7 @@ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd, args->sense_len != SCSI_SENSE_BUFFERSIZE)) return -EINVAL; +retry: req = scsi_alloc_request(sdev->request_queue, opf, args->req_flags); if (IS_ERR(req)) return PTR_ERR(req); @@ -227,7 +314,7 @@ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd, scmd = blk_mq_rq_to_pdu(req); scmd->cmd_len = COMMAND_SIZE(cmd[0]); memcpy(scmd->cmnd, cmd, scmd->cmd_len); - scmd->allowed = retries; + scmd->allowed = ml_retries; scmd->flags |= args->scmd_flags; req->timeout = timeout; req->rq_flags |= RQF_QUIET; @@ -237,6 +324,11 @@ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd, */ blk_execute_rq(req, true); + if (scsi_check_passthrough(scmd, args->failures) == -EAGAIN) { + blk_mq_free_request(req); + goto retry; + } + /* * Some devices (USB mass-storage in particular) may transfer * garbage data together with a residue indicating that the data diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 5ec1e71a09de..4dceabb9dbe1 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -489,6 +489,52 @@ extern int scsi_is_sdev_device(const struct device *); extern int scsi_is_target_device(const struct device *); extern void scsi_sanitize_inquiry_string(unsigned char *s, int len); +/* + * scsi_execute_cmd users can set scsi_failure.result to have + * scsi_check_passthrough fail/retry a command. scsi_failure.result can be a + * specific host byte or message code, or SCMD_FAILURE_RESULT_ANY can be used + * to match any host or message code. + */ +#define SCMD_FAILURE_RESULT_ANY 0x7fffffff +/* + * Set scsi_failure.result to SCMD_FAILURE_STAT_ANY to fail/retry any failure + * scsi_status_is_good returns false for. + */ +#define SCMD_FAILURE_STAT_ANY 0xff +/* + * The following can be set to the scsi_failure sense, asc and ascq fields to + * match on any sense, ASC, or ASCQ value. + */ +#define SCMD_FAILURE_SENSE_ANY 0xff +#define SCMD_FAILURE_ASC_ANY 0xff +#define SCMD_FAILURE_ASCQ_ANY 0xff +/* Always retry a matching failure. */ +#define SCMD_FAILURE_NO_LIMIT -1 + +struct scsi_failure { + int result; + u8 sense; + u8 asc; + u8 ascq; + /* + * Number of times scsi_execute_cmd will retry the failure. It does + * not count for the total_allowed. + */ + s8 allowed; + /* Number of times the failure has been retried. */ + s8 retries; +}; + +struct scsi_failures { + /* + * If a scsi_failure does not have a retry limit setup this limit will + * be used. + */ + int total_allowed; + int total_retries; + struct scsi_failure *failure_definitions; +}; + /* Optional arguments to scsi_execute_cmd */ struct scsi_exec_args { unsigned char *sense; /* sense buffer */ @@ -497,12 +543,14 @@ struct scsi_exec_args { blk_mq_req_flags_t req_flags; /* BLK_MQ_REQ flags */ int scmd_flags; /* SCMD flags */ int *resid; /* residual length */ + struct scsi_failures *failures; /* failures to retry */ }; int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd, blk_opf_t opf, void *buffer, unsigned int bufflen, int timeout, int retries, const struct scsi_exec_args *args); +void scsi_failures_reset_retries(struct scsi_failures *failures); extern void sdev_disable_disk_events(struct scsi_device *sdev); extern void sdev_enable_disk_events(struct scsi_device *sdev); |