diff options
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 411 |
1 files changed, 236 insertions, 175 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 41e9ac9fc138..0adfb3bce0fd 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -238,7 +238,7 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) /** - * scsi_execute - insert request and wait for the result + * __scsi_execute - insert request and wait for the result * @sdev: scsi device * @cmd: scsi command * @data_direction: data direction @@ -255,7 +255,7 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) * Returns the scsi_cmnd result field if a command was executed, or a negative * Linux error code if we didn't get that far. */ -int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, +int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, int data_direction, void *buffer, unsigned bufflen, unsigned char *sense, struct scsi_sense_hdr *sshdr, int timeout, int retries, u64 flags, req_flags_t rq_flags, @@ -309,7 +309,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, return ret; } -EXPORT_SYMBOL(scsi_execute); +EXPORT_SYMBOL(__scsi_execute); /* * Function: scsi_init_cmd_errh() @@ -345,7 +345,8 @@ static void scsi_dec_host_busy(struct Scsi_Host *shost) unsigned long flags; rcu_read_lock(); - atomic_dec(&shost->host_busy); + if (!shost->use_blk_mq) + atomic_dec(&shost->host_busy); if (unlikely(scsi_host_in_recovery(shost))) { spin_lock_irqsave(shost->host_lock, flags); if (shost->host_failed || shost->host_eh_scheduled) @@ -371,7 +372,7 @@ void scsi_device_unbusy(struct scsi_device *sdev) static void scsi_kick_queue(struct request_queue *q) { if (q->mq_ops) - blk_mq_start_hw_queues(q); + blk_mq_run_hw_queues(q, false); else blk_run_queue(q); } @@ -444,7 +445,12 @@ static inline bool scsi_target_is_busy(struct scsi_target *starget) static inline bool scsi_host_is_busy(struct Scsi_Host *shost) { - if (shost->can_queue > 0 && + /* + * blk-mq can handle host queue busy efficiently via host-wide driver + * tag allocation + */ + + if (!shost->use_blk_mq && shost->can_queue > 0 && atomic_read(&shost->host_busy) >= shost->can_queue) return true; if (atomic_read(&shost->host_blocked) > 0) @@ -662,6 +668,7 @@ static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) cmd->request->next_rq->special = NULL; } +/* Returns false when no more bytes to process, true if there are more */ static bool scsi_end_request(struct request *req, blk_status_t error, unsigned int bytes, unsigned int bidi_bytes) { @@ -760,161 +767,39 @@ static blk_status_t scsi_result_to_blk_status(struct scsi_cmnd *cmd, int result) } } -/* - * Function: scsi_io_completion() - * - * Purpose: Completion processing for block device I/O requests. - * - * Arguments: cmd - command that is finished. - * - * Lock status: Assumed that no lock is held upon entry. - * - * Returns: Nothing - * - * Notes: We will finish off the specified number of sectors. If we - * are done, the command block will be released and the queue - * function will be goosed. If we are not done then we have to - * figure out what to do next: - * - * a) We can call scsi_requeue_command(). The request - * will be unprepared and put back on the queue. Then - * a new command will be created for it. This should - * be used if we made forward progress, or if we want - * to switch from READ(10) to READ(6) for example. - * - * b) We can call __scsi_queue_insert(). The request will - * be put back on the queue and retried using the same - * command as before, possibly after a delay. - * - * c) We can call scsi_end_request() with -EIO to fail - * the remainder of the request. - */ -void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) +/* Helper for scsi_io_completion() when "reprep" action required. */ +static void scsi_io_completion_reprep(struct scsi_cmnd *cmd, + struct request_queue *q) +{ + /* A new command will be prepared and issued. */ + if (q->mq_ops) { + scsi_mq_requeue_cmd(cmd); + } else { + /* Unprep request and put it back at head of the queue. */ + scsi_release_buffers(cmd); + scsi_requeue_command(q, cmd); + } +} + +/* Helper for scsi_io_completion() when special action required. */ +static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result) { - int result = cmd->result; struct request_queue *q = cmd->device->request_queue; struct request *req = cmd->request; - blk_status_t error = BLK_STS_OK; - struct scsi_sense_hdr sshdr; - bool sense_valid = false; - int sense_deferred = 0, level = 0; + int level = 0; enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, ACTION_DELAYED_RETRY} action; unsigned long wait_for = (cmd->allowed + 1) * req->timeout; + struct scsi_sense_hdr sshdr; + bool sense_valid; + bool sense_current = true; /* false implies "deferred sense" */ + blk_status_t blk_stat; - if (result) { - sense_valid = scsi_command_normalize_sense(cmd, &sshdr); - if (sense_valid) - sense_deferred = scsi_sense_is_deferred(&sshdr); - } - - if (blk_rq_is_passthrough(req)) { - if (result) { - if (sense_valid) { - /* - * SG_IO wants current and deferred errors - */ - scsi_req(req)->sense_len = - min(8 + cmd->sense_buffer[7], - SCSI_SENSE_BUFFERSIZE); - } - if (!sense_deferred) - error = scsi_result_to_blk_status(cmd, result); - } - /* - * scsi_result_to_blk_status may have reset the host_byte - */ - scsi_req(req)->result = cmd->result; - scsi_req(req)->resid_len = scsi_get_resid(cmd); - - if (scsi_bidi_cmnd(cmd)) { - /* - * Bidi commands Must be complete as a whole, - * both sides at once. - */ - scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid; - if (scsi_end_request(req, BLK_STS_OK, blk_rq_bytes(req), - blk_rq_bytes(req->next_rq))) - BUG(); - return; - } - } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) { - /* - * Flush commands do not transfers any data, and thus cannot use - * good_bytes != blk_rq_bytes(req) as the signal for an error. - * This sets the error explicitly for the problem case. - */ - error = scsi_result_to_blk_status(cmd, result); - } - - /* no bidi support for !blk_rq_is_passthrough yet */ - BUG_ON(blk_bidi_rq(req)); - - /* - * Next deal with any sectors which we were able to correctly - * handle. - */ - SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, - "%u sectors total, %d bytes done.\n", - blk_rq_sectors(req), good_bytes)); - - /* - * Recovered errors need reporting, but they're always treated as - * success, so fiddle the result code here. For passthrough requests - * we already took a copy of the original into sreq->result which - * is what gets returned to the user - */ - if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { - /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip - * print since caller wants ATA registers. Only occurs on - * SCSI ATA PASS_THROUGH commands when CK_COND=1 - */ - if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) - ; - else if (!(req->rq_flags & RQF_QUIET)) - scsi_print_sense(cmd); - result = 0; - /* for passthrough error may be set */ - error = BLK_STS_OK; - } - /* - * Another corner case: the SCSI status byte is non-zero but 'good'. - * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when - * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD - * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related - * intermediate statuses (both obsolete in SAM-4) as good. - */ - if (status_byte(result) && scsi_status_is_good(result)) { - result = 0; - error = BLK_STS_OK; - } - - /* - * special case: failed zero length commands always need to - * drop down into the retry code. Otherwise, if we finished - * all bytes in the request we are done now. - */ - if (!(blk_rq_bytes(req) == 0 && error) && - !scsi_end_request(req, error, good_bytes, 0)) - return; - - /* - * Kill remainder if no retrys. - */ - if (error && scsi_noretry_cmd(cmd)) { - if (scsi_end_request(req, error, blk_rq_bytes(req), 0)) - BUG(); - return; - } - - /* - * If there had been no error, but we have leftover bytes in the - * requeues just queue the command up again. - */ - if (result == 0) - goto requeue; + sense_valid = scsi_command_normalize_sense(cmd, &sshdr); + if (sense_valid) + sense_current = !scsi_sense_is_deferred(&sshdr); - error = scsi_result_to_blk_status(cmd, result); + blk_stat = scsi_result_to_blk_status(cmd, result); if (host_byte(result) == DID_RESET) { /* Third party bus reset or reset for error recovery @@ -922,7 +807,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) * happens. */ action = ACTION_RETRY; - } else if (sense_valid && !sense_deferred) { + } else if (sense_valid && sense_current) { switch (sshdr.sense_key) { case UNIT_ATTENTION: if (cmd->device->removable) { @@ -958,18 +843,18 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) action = ACTION_REPREP; } else if (sshdr.asc == 0x10) /* DIX */ { action = ACTION_FAIL; - error = BLK_STS_PROTECTION; + blk_stat = BLK_STS_PROTECTION; /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { action = ACTION_FAIL; - error = BLK_STS_TARGET; + blk_stat = BLK_STS_TARGET; } else action = ACTION_FAIL; break; case ABORTED_COMMAND: action = ACTION_FAIL; if (sshdr.asc == 0x10) /* DIF */ - error = BLK_STS_PROTECTION; + blk_stat = BLK_STS_PROTECTION; break; case NOT_READY: /* If the device is in the process of becoming @@ -1022,8 +907,9 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) DEFAULT_RATELIMIT_BURST); if (unlikely(scsi_logging_level)) - level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, - SCSI_LOG_MLCOMPLETE_BITS); + level = + SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, + SCSI_LOG_MLCOMPLETE_BITS); /* * if logging is enabled the failure will be printed @@ -1031,25 +917,16 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) */ if (!level && __ratelimit(&_rs)) { scsi_print_result(cmd, NULL, FAILED); - if (driver_byte(result) & DRIVER_SENSE) + if (driver_byte(result) == DRIVER_SENSE) scsi_print_sense(cmd); scsi_print_command(cmd); } } - if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0)) + if (!scsi_end_request(req, blk_stat, blk_rq_err_bytes(req), 0)) return; /*FALLTHRU*/ case ACTION_REPREP: - requeue: - /* Unprep the request and put it back at the head of the queue. - * A new command will be prepared and issued. - */ - if (q->mq_ops) { - scsi_mq_requeue_cmd(cmd); - } else { - scsi_release_buffers(cmd); - scsi_requeue_command(q, cmd); - } + scsi_io_completion_reprep(cmd, q); break; case ACTION_RETRY: /* Retry the same command immediately */ @@ -1062,6 +939,185 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) } } +/* + * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a + * new result that may suppress further error checking. Also modifies + * *blk_statp in some cases. + */ +static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result, + blk_status_t *blk_statp) +{ + bool sense_valid; + bool sense_current = true; /* false implies "deferred sense" */ + struct request *req = cmd->request; + struct scsi_sense_hdr sshdr; + + sense_valid = scsi_command_normalize_sense(cmd, &sshdr); + if (sense_valid) + sense_current = !scsi_sense_is_deferred(&sshdr); + + if (blk_rq_is_passthrough(req)) { + if (sense_valid) { + /* + * SG_IO wants current and deferred errors + */ + scsi_req(req)->sense_len = + min(8 + cmd->sense_buffer[7], + SCSI_SENSE_BUFFERSIZE); + } + if (sense_current) + *blk_statp = scsi_result_to_blk_status(cmd, result); + } else if (blk_rq_bytes(req) == 0 && sense_current) { + /* + * Flush commands do not transfers any data, and thus cannot use + * good_bytes != blk_rq_bytes(req) as the signal for an error. + * This sets *blk_statp explicitly for the problem case. + */ + *blk_statp = scsi_result_to_blk_status(cmd, result); + } + /* + * Recovered errors need reporting, but they're always treated as + * success, so fiddle the result code here. For passthrough requests + * we already took a copy of the original into sreq->result which + * is what gets returned to the user + */ + if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { + bool do_print = true; + /* + * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d] + * skip print since caller wants ATA registers. Only occurs + * on SCSI ATA PASS_THROUGH commands when CK_COND=1 + */ + if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) + do_print = false; + else if (req->rq_flags & RQF_QUIET) + do_print = false; + if (do_print) + scsi_print_sense(cmd); + result = 0; + /* for passthrough, *blk_statp may be set */ + *blk_statp = BLK_STS_OK; + } + /* + * Another corner case: the SCSI status byte is non-zero but 'good'. + * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when + * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD + * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related + * intermediate statuses (both obsolete in SAM-4) as good. + */ + if (status_byte(result) && scsi_status_is_good(result)) { + result = 0; + *blk_statp = BLK_STS_OK; + } + return result; +} + +/* + * Function: scsi_io_completion() + * + * Purpose: Completion processing for block device I/O requests. + * + * Arguments: cmd - command that is finished. + * + * Lock status: Assumed that no lock is held upon entry. + * + * Returns: Nothing + * + * Notes: We will finish off the specified number of sectors. If we + * are done, the command block will be released and the queue + * function will be goosed. If we are not done then we have to + * figure out what to do next: + * + * a) We can call scsi_requeue_command(). The request + * will be unprepared and put back on the queue. Then + * a new command will be created for it. This should + * be used if we made forward progress, or if we want + * to switch from READ(10) to READ(6) for example. + * + * b) We can call __scsi_queue_insert(). The request will + * be put back on the queue and retried using the same + * command as before, possibly after a delay. + * + * c) We can call scsi_end_request() with blk_stat other than + * BLK_STS_OK, to fail the remainder of the request. + */ +void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) +{ + int result = cmd->result; + struct request_queue *q = cmd->device->request_queue; + struct request *req = cmd->request; + blk_status_t blk_stat = BLK_STS_OK; + + if (unlikely(result)) /* a nz result may or may not be an error */ + result = scsi_io_completion_nz_result(cmd, result, &blk_stat); + + if (unlikely(blk_rq_is_passthrough(req))) { + /* + * scsi_result_to_blk_status may have reset the host_byte + */ + scsi_req(req)->result = cmd->result; + scsi_req(req)->resid_len = scsi_get_resid(cmd); + + if (unlikely(scsi_bidi_cmnd(cmd))) { + /* + * Bidi commands Must be complete as a whole, + * both sides at once. + */ + scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid; + if (scsi_end_request(req, BLK_STS_OK, blk_rq_bytes(req), + blk_rq_bytes(req->next_rq))) + WARN_ONCE(true, + "Bidi command with remaining bytes"); + return; + } + } + + /* no bidi support yet, other than in pass-through */ + if (unlikely(blk_bidi_rq(req))) { + WARN_ONCE(true, "Only support bidi command in passthrough"); + scmd_printk(KERN_ERR, cmd, "Killing bidi command\n"); + if (scsi_end_request(req, BLK_STS_IOERR, blk_rq_bytes(req), + blk_rq_bytes(req->next_rq))) + WARN_ONCE(true, "Bidi command with remaining bytes"); + return; + } + + /* + * Next deal with any sectors which we were able to correctly + * handle. + */ + SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, + "%u sectors total, %d bytes done.\n", + blk_rq_sectors(req), good_bytes)); + + /* + * Next deal with any sectors which we were able to correctly + * handle. Failed, zero length commands always need to drop down + * to retry code. Fast path should return in this block. + */ + if (likely(blk_rq_bytes(req) > 0 || blk_stat == BLK_STS_OK)) { + if (likely(!scsi_end_request(req, blk_stat, good_bytes, 0))) + return; /* no bytes remaining */ + } + + /* Kill remainder if no retries. */ + if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) { + if (scsi_end_request(req, blk_stat, blk_rq_bytes(req), 0)) + WARN_ONCE(true, + "Bytes remaining after failed, no-retry command"); + return; + } + + /* + * If there had been no error, but we have leftover bytes in the + * requeues just queue the command up again. + */ + if (likely(result == 0)) + scsi_io_completion_reprep(cmd, q); + else + scsi_io_completion_action(cmd, result); +} + static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb) { int count; @@ -1550,7 +1606,10 @@ static inline int scsi_host_queue_ready(struct request_queue *q, if (scsi_host_in_recovery(shost)) return 0; - busy = atomic_inc_return(&shost->host_busy) - 1; + if (!shost->use_blk_mq) + busy = atomic_inc_return(&shost->host_busy) - 1; + else + busy = 0; if (atomic_read(&shost->host_blocked) > 0) { if (busy) goto starved; @@ -1566,7 +1625,7 @@ static inline int scsi_host_queue_ready(struct request_queue *q, "unblocking host at zero depth\n")); } - if (shost->can_queue > 0 && busy >= shost->can_queue) + if (!shost->use_blk_mq && shost->can_queue > 0 && busy >= shost->can_queue) goto starved; if (shost->host_self_blocked) goto starved; @@ -1652,7 +1711,9 @@ static void scsi_kill_request(struct request *req, struct request_queue *q) * with the locks as normal issue path does. */ atomic_inc(&sdev->device_busy); - atomic_inc(&shost->host_busy); + + if (!shost->use_blk_mq) + atomic_inc(&shost->host_busy); if (starget->can_queue > 0) atomic_inc(&starget->target_busy); @@ -2555,7 +2616,7 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, * ILLEGAL REQUEST if the code page isn't supported */ if (use_10_for_ms && !scsi_status_is_good(result) && - (driver_byte(result) & DRIVER_SENSE)) { + driver_byte(result) == DRIVER_SENSE) { if (scsi_sense_valid(sshdr)) { if ((sshdr->sense_key == ILLEGAL_REQUEST) && (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { |