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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright (C) 1999 Eric Youngdale
- * Copyright (C) 2014 Christoph Hellwig
- *
- * SCSI queueing library.
- * Initial versions: Eric Youngdale (eric@andante.org).
- * Based upon conversations with large numbers
- * of people at Linux Expo.
- */
- #include <linux/bio.h>
- #include <linux/bitops.h>
- #include <linux/blkdev.h>
- #include <linux/completion.h>
- #include <linux/kernel.h>
- #include <linux/export.h>
- #include <linux/init.h>
- #include <linux/pci.h>
- #include <linux/delay.h>
- #include <linux/hardirq.h>
- #include <linux/scatterlist.h>
- #include <linux/blk-mq.h>
- #include <linux/ratelimit.h>
- #include <asm/unaligned.h>
- #include <scsi/scsi.h>
- #include <scsi/scsi_cmnd.h>
- #include <scsi/scsi_dbg.h>
- #include <scsi/scsi_device.h>
- #include <scsi/scsi_driver.h>
- #include <scsi/scsi_eh.h>
- #include <scsi/scsi_host.h>
- #include <scsi/scsi_transport.h> /* __scsi_init_queue() */
- #include <scsi/scsi_dh.h>
- #include <trace/events/scsi.h>
- #include "scsi_debugfs.h"
- #include "scsi_priv.h"
- #include "scsi_logging.h"
- /*
- * Size of integrity metadata is usually small, 1 inline sg should
- * cover normal cases.
- */
- #ifdef CONFIG_ARCH_NO_SG_CHAIN
- #define SCSI_INLINE_PROT_SG_CNT 0
- #define SCSI_INLINE_SG_CNT 0
- #else
- #define SCSI_INLINE_PROT_SG_CNT 1
- #define SCSI_INLINE_SG_CNT 2
- #endif
- static struct kmem_cache *scsi_sense_cache;
- static struct kmem_cache *scsi_sense_isadma_cache;
- static DEFINE_MUTEX(scsi_sense_cache_mutex);
- static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd);
- static inline struct kmem_cache *
- scsi_select_sense_cache(bool unchecked_isa_dma)
- {
- return unchecked_isa_dma ? scsi_sense_isadma_cache : scsi_sense_cache;
- }
- static void scsi_free_sense_buffer(bool unchecked_isa_dma,
- unsigned char *sense_buffer)
- {
- kmem_cache_free(scsi_select_sense_cache(unchecked_isa_dma),
- sense_buffer);
- }
- static unsigned char *scsi_alloc_sense_buffer(bool unchecked_isa_dma,
- gfp_t gfp_mask, int numa_node)
- {
- return kmem_cache_alloc_node(scsi_select_sense_cache(unchecked_isa_dma),
- gfp_mask, numa_node);
- }
- int scsi_init_sense_cache(struct Scsi_Host *shost)
- {
- struct kmem_cache *cache;
- int ret = 0;
- mutex_lock(&scsi_sense_cache_mutex);
- cache = scsi_select_sense_cache(shost->unchecked_isa_dma);
- if (cache)
- goto exit;
- if (shost->unchecked_isa_dma) {
- scsi_sense_isadma_cache =
- kmem_cache_create("scsi_sense_cache(DMA)",
- SCSI_SENSE_BUFFERSIZE, 0,
- SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL);
- if (!scsi_sense_isadma_cache)
- ret = -ENOMEM;
- } else {
- scsi_sense_cache =
- kmem_cache_create_usercopy("scsi_sense_cache",
- SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN,
- 0, SCSI_SENSE_BUFFERSIZE, NULL);
- if (!scsi_sense_cache)
- ret = -ENOMEM;
- }
- exit:
- mutex_unlock(&scsi_sense_cache_mutex);
- return ret;
- }
- /*
- * When to reinvoke queueing after a resource shortage. It's 3 msecs to
- * not change behaviour from the previous unplug mechanism, experimentation
- * may prove this needs changing.
- */
- #define SCSI_QUEUE_DELAY 3
- static void
- scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
- {
- struct Scsi_Host *host = cmd->device->host;
- struct scsi_device *device = cmd->device;
- struct scsi_target *starget = scsi_target(device);
- /*
- * Set the appropriate busy bit for the device/host.
- *
- * If the host/device isn't busy, assume that something actually
- * completed, and that we should be able to queue a command now.
- *
- * Note that the prior mid-layer assumption that any host could
- * always queue at least one command is now broken. The mid-layer
- * will implement a user specifiable stall (see
- * scsi_host.max_host_blocked and scsi_device.max_device_blocked)
- * if a command is requeued with no other commands outstanding
- * either for the device or for the host.
- */
- switch (reason) {
- case SCSI_MLQUEUE_HOST_BUSY:
- atomic_set(&host->host_blocked, host->max_host_blocked);
- break;
- case SCSI_MLQUEUE_DEVICE_BUSY:
- case SCSI_MLQUEUE_EH_RETRY:
- atomic_set(&device->device_blocked,
- device->max_device_blocked);
- break;
- case SCSI_MLQUEUE_TARGET_BUSY:
- atomic_set(&starget->target_blocked,
- starget->max_target_blocked);
- break;
- }
- }
- static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
- {
- if (cmd->request->rq_flags & RQF_DONTPREP) {
- cmd->request->rq_flags &= ~RQF_DONTPREP;
- scsi_mq_uninit_cmd(cmd);
- } else {
- WARN_ON_ONCE(true);
- }
- blk_mq_requeue_request(cmd->request, true);
- }
- /**
- * __scsi_queue_insert - private queue insertion
- * @cmd: The SCSI command being requeued
- * @reason: The reason for the requeue
- * @unbusy: Whether the queue should be unbusied
- *
- * This is a private queue insertion. The public interface
- * scsi_queue_insert() always assumes the queue should be unbusied
- * because it's always called before the completion. This function is
- * for a requeue after completion, which should only occur in this
- * file.
- */
- static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
- {
- struct scsi_device *device = cmd->device;
- SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd,
- "Inserting command %p into mlqueue\n", cmd));
- scsi_set_blocked(cmd, reason);
- /*
- * Decrement the counters, since these commands are no longer
- * active on the host/device.
- */
- if (unbusy)
- scsi_device_unbusy(device, cmd);
- /*
- * Requeue this command. It will go before all other commands
- * that are already in the queue. Schedule requeue work under
- * lock such that the kblockd_schedule_work() call happens
- * before blk_cleanup_queue() finishes.
- */
- cmd->result = 0;
- blk_mq_requeue_request(cmd->request, true);
- }
- /**
- * scsi_queue_insert - Reinsert a command in the queue.
- * @cmd: command that we are adding to queue.
- * @reason: why we are inserting command to queue.
- *
- * We do this for one of two cases. Either the host is busy and it cannot accept
- * any more commands for the time being, or the device returned QUEUE_FULL and
- * can accept no more commands.
- *
- * Context: This could be called either from an interrupt context or a normal
- * process context.
- */
- void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
- {
- __scsi_queue_insert(cmd, reason, true);
- }
- /**
- * __scsi_execute - insert request and wait for the result
- * @sdev: scsi device
- * @cmd: scsi command
- * @data_direction: data direction
- * @buffer: data buffer
- * @bufflen: len of buffer
- * @sense: optional sense buffer
- * @sshdr: optional decoded sense header
- * @timeout: request timeout in seconds
- * @retries: number of times to retry request
- * @flags: flags for ->cmd_flags
- * @rq_flags: flags for ->rq_flags
- * @resid: optional residual length
- *
- * 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 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,
- int *resid)
- {
- struct request *req;
- struct scsi_request *rq;
- int ret = DRIVER_ERROR << 24;
- req = blk_get_request(sdev->request_queue,
- data_direction == DMA_TO_DEVICE ?
- REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
- rq_flags & RQF_PM ? BLK_MQ_REQ_PM : 0);
- if (IS_ERR(req))
- return ret;
- rq = scsi_req(req);
- if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
- buffer, bufflen, GFP_NOIO))
- goto out;
- rq->cmd_len = COMMAND_SIZE(cmd[0]);
- memcpy(rq->cmd, cmd, rq->cmd_len);
- rq->retries = retries;
- req->timeout = timeout;
- req->cmd_flags |= flags;
- req->rq_flags |= rq_flags | RQF_QUIET;
- /*
- * head injection *required* here otherwise quiesce won't work
- */
- blk_execute_rq(req->q, NULL, req, 1);
- /*
- * Some devices (USB mass-storage in particular) may transfer
- * garbage data together with a residue indicating that the data
- * is invalid. Prevent the garbage from being misinterpreted
- * and prevent security leaks by zeroing out the excess data.
- */
- if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen))
- memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len);
- if (resid)
- *resid = rq->resid_len;
- if (sense && rq->sense_len)
- memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
- if (sshdr)
- scsi_normalize_sense(rq->sense, rq->sense_len, sshdr);
- ret = rq->result;
- out:
- blk_put_request(req);
- return ret;
- }
- EXPORT_SYMBOL(__scsi_execute);
- /*
- * Wake up the error handler if necessary. Avoid as follows that the error
- * handler is not woken up if host in-flight requests number ==
- * shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination
- * with an RCU read lock in this function to ensure that this function in
- * its entirety either finishes before scsi_eh_scmd_add() increases the
- * host_failed counter or that it notices the shost state change made by
- * scsi_eh_scmd_add().
- */
- static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
- {
- unsigned long flags;
- rcu_read_lock();
- __clear_bit(SCMD_STATE_INFLIGHT, &cmd->state);
- if (unlikely(scsi_host_in_recovery(shost))) {
- spin_lock_irqsave(shost->host_lock, flags);
- if (shost->host_failed || shost->host_eh_scheduled)
- scsi_eh_wakeup(shost);
- spin_unlock_irqrestore(shost->host_lock, flags);
- }
- rcu_read_unlock();
- }
- void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd)
- {
- struct Scsi_Host *shost = sdev->host;
- struct scsi_target *starget = scsi_target(sdev);
- scsi_dec_host_busy(shost, cmd);
- if (starget->can_queue > 0)
- atomic_dec(&starget->target_busy);
- atomic_dec(&sdev->device_busy);
- }
- static void scsi_kick_queue(struct request_queue *q)
- {
- blk_mq_run_hw_queues(q, false);
- }
- /*
- * Called for single_lun devices on IO completion. Clear starget_sdev_user,
- * and call blk_run_queue for all the scsi_devices on the target -
- * including current_sdev first.
- *
- * Called with *no* scsi locks held.
- */
- static void scsi_single_lun_run(struct scsi_device *current_sdev)
- {
- struct Scsi_Host *shost = current_sdev->host;
- struct scsi_device *sdev, *tmp;
- struct scsi_target *starget = scsi_target(current_sdev);
- unsigned long flags;
- spin_lock_irqsave(shost->host_lock, flags);
- starget->starget_sdev_user = NULL;
- spin_unlock_irqrestore(shost->host_lock, flags);
- /*
- * Call blk_run_queue for all LUNs on the target, starting with
- * current_sdev. We race with others (to set starget_sdev_user),
- * but in most cases, we will be first. Ideally, each LU on the
- * target would get some limited time or requests on the target.
- */
- scsi_kick_queue(current_sdev->request_queue);
- spin_lock_irqsave(shost->host_lock, flags);
- if (starget->starget_sdev_user)
- goto out;
- list_for_each_entry_safe(sdev, tmp, &starget->devices,
- same_target_siblings) {
- if (sdev == current_sdev)
- continue;
- if (scsi_device_get(sdev))
- continue;
- spin_unlock_irqrestore(shost->host_lock, flags);
- scsi_kick_queue(sdev->request_queue);
- spin_lock_irqsave(shost->host_lock, flags);
- scsi_device_put(sdev);
- }
- out:
- spin_unlock_irqrestore(shost->host_lock, flags);
- }
- static inline bool scsi_device_is_busy(struct scsi_device *sdev)
- {
- if (atomic_read(&sdev->device_busy) >= sdev->queue_depth)
- return true;
- if (atomic_read(&sdev->device_blocked) > 0)
- return true;
- return false;
- }
- static inline bool scsi_target_is_busy(struct scsi_target *starget)
- {
- if (starget->can_queue > 0) {
- if (atomic_read(&starget->target_busy) >= starget->can_queue)
- return true;
- if (atomic_read(&starget->target_blocked) > 0)
- return true;
- }
- return false;
- }
- static inline bool scsi_host_is_busy(struct Scsi_Host *shost)
- {
- if (atomic_read(&shost->host_blocked) > 0)
- return true;
- if (shost->host_self_blocked)
- return true;
- return false;
- }
- static void scsi_starved_list_run(struct Scsi_Host *shost)
- {
- LIST_HEAD(starved_list);
- struct scsi_device *sdev;
- unsigned long flags;
- spin_lock_irqsave(shost->host_lock, flags);
- list_splice_init(&shost->starved_list, &starved_list);
- while (!list_empty(&starved_list)) {
- struct request_queue *slq;
- /*
- * As long as shost is accepting commands and we have
- * starved queues, call blk_run_queue. scsi_request_fn
- * drops the queue_lock and can add us back to the
- * starved_list.
- *
- * host_lock protects the starved_list and starved_entry.
- * scsi_request_fn must get the host_lock before checking
- * or modifying starved_list or starved_entry.
- */
- if (scsi_host_is_busy(shost))
- break;
- sdev = list_entry(starved_list.next,
- struct scsi_device, starved_entry);
- list_del_init(&sdev->starved_entry);
- if (scsi_target_is_busy(scsi_target(sdev))) {
- list_move_tail(&sdev->starved_entry,
- &shost->starved_list);
- continue;
- }
- /*
- * Once we drop the host lock, a racing scsi_remove_device()
- * call may remove the sdev from the starved list and destroy
- * it and the queue. Mitigate by taking a reference to the
- * queue and never touching the sdev again after we drop the
- * host lock. Note: if __scsi_remove_device() invokes
- * blk_cleanup_queue() before the queue is run from this
- * function then blk_run_queue() will return immediately since
- * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING.
- */
- slq = sdev->request_queue;
- if (!blk_get_queue(slq))
- continue;
- spin_unlock_irqrestore(shost->host_lock, flags);
- scsi_kick_queue(slq);
- blk_put_queue(slq);
- spin_lock_irqsave(shost->host_lock, flags);
- }
- /* put any unprocessed entries back */
- list_splice(&starved_list, &shost->starved_list);
- spin_unlock_irqrestore(shost->host_lock, flags);
- }
- /**
- * scsi_run_queue - Select a proper request queue to serve next.
- * @q: last request's queue
- *
- * The previous command was completely finished, start a new one if possible.
- */
- static void scsi_run_queue(struct request_queue *q)
- {
- struct scsi_device *sdev = q->queuedata;
- if (scsi_target(sdev)->single_lun)
- scsi_single_lun_run(sdev);
- if (!list_empty(&sdev->host->starved_list))
- scsi_starved_list_run(sdev->host);
- blk_mq_run_hw_queues(q, false);
- }
- void scsi_requeue_run_queue(struct work_struct *work)
- {
- struct scsi_device *sdev;
- struct request_queue *q;
- sdev = container_of(work, struct scsi_device, requeue_work);
- q = sdev->request_queue;
- scsi_run_queue(q);
- }
- void scsi_run_host_queues(struct Scsi_Host *shost)
- {
- struct scsi_device *sdev;
- shost_for_each_device(sdev, shost)
- scsi_run_queue(sdev->request_queue);
- }
- static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
- {
- if (!blk_rq_is_passthrough(cmd->request)) {
- struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
- if (drv->uninit_command)
- drv->uninit_command(cmd);
- }
- }
- void scsi_free_sgtables(struct scsi_cmnd *cmd)
- {
- if (cmd->sdb.table.nents)
- sg_free_table_chained(&cmd->sdb.table,
- SCSI_INLINE_SG_CNT);
- if (scsi_prot_sg_count(cmd))
- sg_free_table_chained(&cmd->prot_sdb->table,
- SCSI_INLINE_PROT_SG_CNT);
- }
- EXPORT_SYMBOL_GPL(scsi_free_sgtables);
- static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
- {
- scsi_free_sgtables(cmd);
- scsi_uninit_cmd(cmd);
- }
- static void scsi_run_queue_async(struct scsi_device *sdev)
- {
- if (scsi_target(sdev)->single_lun ||
- !list_empty(&sdev->host->starved_list)) {
- kblockd_schedule_work(&sdev->requeue_work);
- } else {
- /*
- * smp_mb() present in sbitmap_queue_clear() or implied in
- * .end_io is for ordering writing .device_busy in
- * scsi_device_unbusy() and reading sdev->restarts.
- */
- int old = atomic_read(&sdev->restarts);
- /*
- * ->restarts has to be kept as non-zero if new budget
- * contention occurs.
- *
- * No need to run queue when either another re-run
- * queue wins in updating ->restarts or a new budget
- * contention occurs.
- */
- if (old && atomic_cmpxchg(&sdev->restarts, old, 0) == old)
- blk_mq_run_hw_queues(sdev->request_queue, true);
- }
- }
- /* 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)
- {
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
- struct scsi_device *sdev = cmd->device;
- struct request_queue *q = sdev->request_queue;
- if (blk_update_request(req, error, bytes))
- return true;
- if (blk_queue_add_random(q))
- add_disk_randomness(req->rq_disk);
- if (!blk_rq_is_scsi(req)) {
- WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED));
- cmd->flags &= ~SCMD_INITIALIZED;
- }
- /*
- * Calling rcu_barrier() is not necessary here because the
- * SCSI error handler guarantees that the function called by
- * call_rcu() has been called before scsi_end_request() is
- * called.
- */
- destroy_rcu_head(&cmd->rcu);
- /*
- * In the MQ case the command gets freed by __blk_mq_end_request,
- * so we have to do all cleanup that depends on it earlier.
- *
- * We also can't kick the queues from irq context, so we
- * will have to defer it to a workqueue.
- */
- scsi_mq_uninit_cmd(cmd);
- /*
- * queue is still alive, so grab the ref for preventing it
- * from being cleaned up during running queue.
- */
- percpu_ref_get(&q->q_usage_counter);
- __blk_mq_end_request(req, error);
- scsi_run_queue_async(sdev);
- percpu_ref_put(&q->q_usage_counter);
- return false;
- }
- /**
- * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t
- * @cmd: SCSI command
- * @result: scsi error code
- *
- * Translate a SCSI result code into a blk_status_t value. May reset the host
- * byte of @cmd->result.
- */
- static blk_status_t scsi_result_to_blk_status(struct scsi_cmnd *cmd, int result)
- {
- switch (host_byte(result)) {
- case DID_OK:
- /*
- * Also check the other bytes than the status byte in result
- * to handle the case when a SCSI LLD sets result to
- * DRIVER_SENSE << 24 without setting SAM_STAT_CHECK_CONDITION.
- */
- if (scsi_status_is_good(result) && (result & ~0xff) == 0)
- return BLK_STS_OK;
- return BLK_STS_IOERR;
- case DID_TRANSPORT_FAILFAST:
- return BLK_STS_TRANSPORT;
- case DID_TARGET_FAILURE:
- set_host_byte(cmd, DID_OK);
- return BLK_STS_TARGET;
- case DID_NEXUS_FAILURE:
- set_host_byte(cmd, DID_OK);
- return BLK_STS_NEXUS;
- case DID_ALLOC_FAILURE:
- set_host_byte(cmd, DID_OK);
- return BLK_STS_NOSPC;
- case DID_MEDIUM_ERROR:
- set_host_byte(cmd, DID_OK);
- return BLK_STS_MEDIUM;
- default:
- return BLK_STS_IOERR;
- }
- }
- /* 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. */
- scsi_mq_requeue_cmd(cmd);
- }
- static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd)
- {
- struct request *req = cmd->request;
- unsigned long wait_for;
- if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
- return false;
- wait_for = (cmd->allowed + 1) * req->timeout;
- if (time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
- scmd_printk(KERN_ERR, cmd, "timing out command, waited %lus\n",
- wait_for/HZ);
- return true;
- }
- return false;
- }
- /* Helper for scsi_io_completion() when special action required. */
- static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
- {
- struct request_queue *q = cmd->device->request_queue;
- struct request *req = cmd->request;
- int level = 0;
- enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
- ACTION_DELAYED_RETRY} action;
- struct scsi_sense_hdr sshdr;
- bool sense_valid;
- bool sense_current = true; /* false implies "deferred sense" */
- blk_status_t blk_stat;
- sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
- if (sense_valid)
- sense_current = !scsi_sense_is_deferred(&sshdr);
- blk_stat = scsi_result_to_blk_status(cmd, result);
- if (host_byte(result) == DID_RESET) {
- /* Third party bus reset or reset for error recovery
- * reasons. Just retry the command and see what
- * happens.
- */
- action = ACTION_RETRY;
- } else if (sense_valid && sense_current) {
- switch (sshdr.sense_key) {
- case UNIT_ATTENTION:
- if (cmd->device->removable) {
- /* Detected disc change. Set a bit
- * and quietly refuse further access.
- */
- cmd->device->changed = 1;
- action = ACTION_FAIL;
- } else {
- /* Must have been a power glitch, or a
- * bus reset. Could not have been a
- * media change, so we just retry the
- * command and see what happens.
- */
- action = ACTION_RETRY;
- }
- break;
- case ILLEGAL_REQUEST:
- /* If we had an ILLEGAL REQUEST returned, then
- * we may have performed an unsupported
- * command. The only thing this should be
- * would be a ten byte read where only a six
- * byte read was supported. Also, on a system
- * where READ CAPACITY failed, we may have
- * read past the end of the disk.
- */
- if ((cmd->device->use_10_for_rw &&
- sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
- (cmd->cmnd[0] == READ_10 ||
- cmd->cmnd[0] == WRITE_10)) {
- /* This will issue a new 6-byte command. */
- cmd->device->use_10_for_rw = 0;
- action = ACTION_REPREP;
- } else if (sshdr.asc == 0x10) /* DIX */ {
- action = ACTION_FAIL;
- blk_stat = BLK_STS_PROTECTION;
- /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
- } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
- action = ACTION_FAIL;
- blk_stat = BLK_STS_TARGET;
- } else
- action = ACTION_FAIL;
- break;
- case ABORTED_COMMAND:
- action = ACTION_FAIL;
- if (sshdr.asc == 0x10) /* DIF */
- blk_stat = BLK_STS_PROTECTION;
- break;
- case NOT_READY:
- /* If the device is in the process of becoming
- * ready, or has a temporary blockage, retry.
- */
- if (sshdr.asc == 0x04) {
- switch (sshdr.ascq) {
- case 0x01: /* becoming ready */
- case 0x04: /* format in progress */
- case 0x05: /* rebuild in progress */
- case 0x06: /* recalculation in progress */
- case 0x07: /* operation in progress */
- case 0x08: /* Long write in progress */
- case 0x09: /* self test in progress */
- case 0x11: /* notify (enable spinup) required */
- case 0x14: /* space allocation in progress */
- case 0x1a: /* start stop unit in progress */
- case 0x1b: /* sanitize in progress */
- case 0x1d: /* configuration in progress */
- case 0x24: /* depopulation in progress */
- action = ACTION_DELAYED_RETRY;
- break;
- default:
- action = ACTION_FAIL;
- break;
- }
- } else
- action = ACTION_FAIL;
- break;
- case VOLUME_OVERFLOW:
- /* See SSC3rXX or current. */
- action = ACTION_FAIL;
- break;
- case DATA_PROTECT:
- action = ACTION_FAIL;
- if ((sshdr.asc == 0x0C && sshdr.ascq == 0x12) ||
- (sshdr.asc == 0x55 &&
- (sshdr.ascq == 0x0E || sshdr.ascq == 0x0F))) {
- /* Insufficient zone resources */
- blk_stat = BLK_STS_ZONE_OPEN_RESOURCE;
- }
- break;
- default:
- action = ACTION_FAIL;
- break;
- }
- } else
- action = ACTION_FAIL;
- if (action != ACTION_FAIL && scsi_cmd_runtime_exceeced(cmd))
- action = ACTION_FAIL;
- switch (action) {
- case ACTION_FAIL:
- /* Give up and fail the remainder of the request */
- if (!(req->rq_flags & RQF_QUIET)) {
- static DEFINE_RATELIMIT_STATE(_rs,
- DEFAULT_RATELIMIT_INTERVAL,
- DEFAULT_RATELIMIT_BURST);
- if (unlikely(scsi_logging_level))
- level =
- SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
- SCSI_LOG_MLCOMPLETE_BITS);
- /*
- * if logging is enabled the failure will be printed
- * in scsi_log_completion(), so avoid duplicate messages
- */
- if (!level && __ratelimit(&_rs)) {
- scsi_print_result(cmd, NULL, FAILED);
- if (driver_byte(result) == DRIVER_SENSE)
- scsi_print_sense(cmd);
- scsi_print_command(cmd);
- }
- }
- if (!scsi_end_request(req, blk_stat, blk_rq_err_bytes(req)))
- return;
- fallthrough;
- case ACTION_REPREP:
- scsi_io_completion_reprep(cmd, q);
- break;
- case ACTION_RETRY:
- /* Retry the same command immediately */
- __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false);
- break;
- case ACTION_DELAYED_RETRY:
- /* Retry the same command after a delay */
- __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false);
- break;
- }
- }
- /*
- * 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;
- }
- /**
- * scsi_io_completion - Completion processing for SCSI commands.
- * @cmd: command that is finished.
- * @good_bytes: number of processed bytes.
- *
- * 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_io_completion_reprep(). 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_io_completion_action(). 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;
- }
- /*
- * 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));
- /*
- * 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)))
- 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)))
- 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 inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev,
- struct request *rq)
- {
- return sdev->dma_drain_len && blk_rq_is_passthrough(rq) &&
- !op_is_write(req_op(rq)) &&
- sdev->host->hostt->dma_need_drain(rq);
- }
- /**
- * scsi_alloc_sgtables - allocate S/G tables for a command
- * @cmd: command descriptor we wish to initialize
- *
- * Returns:
- * * BLK_STS_OK - on success
- * * BLK_STS_RESOURCE - if the failure is retryable
- * * BLK_STS_IOERR - if the failure is fatal
- */
- blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd)
- {
- struct scsi_device *sdev = cmd->device;
- struct request *rq = cmd->request;
- unsigned short nr_segs = blk_rq_nr_phys_segments(rq);
- struct scatterlist *last_sg = NULL;
- blk_status_t ret;
- bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq);
- int count;
- if (WARN_ON_ONCE(!nr_segs))
- return BLK_STS_IOERR;
- /*
- * Make sure there is space for the drain. The driver must adjust
- * max_hw_segments to be prepared for this.
- */
- if (need_drain)
- nr_segs++;
- /*
- * If sg table allocation fails, requeue request later.
- */
- if (unlikely(sg_alloc_table_chained(&cmd->sdb.table, nr_segs,
- cmd->sdb.table.sgl, SCSI_INLINE_SG_CNT)))
- return BLK_STS_RESOURCE;
- /*
- * Next, walk the list, and fill in the addresses and sizes of
- * each segment.
- */
- count = __blk_rq_map_sg(rq->q, rq, cmd->sdb.table.sgl, &last_sg);
- if (blk_rq_bytes(rq) & rq->q->dma_pad_mask) {
- unsigned int pad_len =
- (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
- last_sg->length += pad_len;
- cmd->extra_len += pad_len;
- }
- if (need_drain) {
- sg_unmark_end(last_sg);
- last_sg = sg_next(last_sg);
- sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len);
- sg_mark_end(last_sg);
- cmd->extra_len += sdev->dma_drain_len;
- count++;
- }
- BUG_ON(count > cmd->sdb.table.nents);
- cmd->sdb.table.nents = count;
- cmd->sdb.length = blk_rq_payload_bytes(rq);
- if (blk_integrity_rq(rq)) {
- struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
- int ivecs;
- if (WARN_ON_ONCE(!prot_sdb)) {
- /*
- * This can happen if someone (e.g. multipath)
- * queues a command to a device on an adapter
- * that does not support DIX.
- */
- ret = BLK_STS_IOERR;
- goto out_free_sgtables;
- }
- ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
- if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
- prot_sdb->table.sgl,
- SCSI_INLINE_PROT_SG_CNT)) {
- ret = BLK_STS_RESOURCE;
- goto out_free_sgtables;
- }
- count = blk_rq_map_integrity_sg(rq->q, rq->bio,
- prot_sdb->table.sgl);
- BUG_ON(count > ivecs);
- BUG_ON(count > queue_max_integrity_segments(rq->q));
- cmd->prot_sdb = prot_sdb;
- cmd->prot_sdb->table.nents = count;
- }
- return BLK_STS_OK;
- out_free_sgtables:
- scsi_free_sgtables(cmd);
- return ret;
- }
- EXPORT_SYMBOL(scsi_alloc_sgtables);
- /**
- * scsi_initialize_rq - initialize struct scsi_cmnd partially
- * @rq: Request associated with the SCSI command to be initialized.
- *
- * This function initializes the members of struct scsi_cmnd that must be
- * initialized before request processing starts and that won't be
- * reinitialized if a SCSI command is requeued.
- *
- * Called from inside blk_get_request() for pass-through requests and from
- * inside scsi_init_command() for filesystem requests.
- */
- static void scsi_initialize_rq(struct request *rq)
- {
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- scsi_req_init(&cmd->req);
- init_rcu_head(&cmd->rcu);
- cmd->jiffies_at_alloc = jiffies;
- cmd->retries = 0;
- }
- /*
- * Only called when the request isn't completed by SCSI, and not freed by
- * SCSI
- */
- static void scsi_cleanup_rq(struct request *rq)
- {
- if (rq->rq_flags & RQF_DONTPREP) {
- scsi_mq_uninit_cmd(blk_mq_rq_to_pdu(rq));
- rq->rq_flags &= ~RQF_DONTPREP;
- }
- }
- /* Called before a request is prepared. See also scsi_mq_prep_fn(). */
- void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
- {
- void *buf = cmd->sense_buffer;
- void *prot = cmd->prot_sdb;
- struct request *rq = blk_mq_rq_from_pdu(cmd);
- unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS;
- unsigned long jiffies_at_alloc;
- int retries, to_clear;
- bool in_flight;
- if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) {
- flags |= SCMD_INITIALIZED;
- scsi_initialize_rq(rq);
- }
- jiffies_at_alloc = cmd->jiffies_at_alloc;
- retries = cmd->retries;
- in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state);
- /*
- * Zero out the cmd, except for the embedded scsi_request. Only clear
- * the driver-private command data if the LLD does not supply a
- * function to initialize that data.
- */
- to_clear = sizeof(*cmd) - sizeof(cmd->req);
- if (!dev->host->hostt->init_cmd_priv)
- to_clear += dev->host->hostt->cmd_size;
- memset((char *)cmd + sizeof(cmd->req), 0, to_clear);
- cmd->device = dev;
- cmd->sense_buffer = buf;
- cmd->prot_sdb = prot;
- cmd->flags = flags;
- INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
- cmd->jiffies_at_alloc = jiffies_at_alloc;
- cmd->retries = retries;
- if (in_flight)
- __set_bit(SCMD_STATE_INFLIGHT, &cmd->state);
- }
- static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
- struct request *req)
- {
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
- /*
- * Passthrough requests may transfer data, in which case they must
- * a bio attached to them. Or they might contain a SCSI command
- * that does not transfer data, in which case they may optionally
- * submit a request without an attached bio.
- */
- if (req->bio) {
- blk_status_t ret = scsi_alloc_sgtables(cmd);
- if (unlikely(ret != BLK_STS_OK))
- return ret;
- } else {
- BUG_ON(blk_rq_bytes(req));
- memset(&cmd->sdb, 0, sizeof(cmd->sdb));
- }
- cmd->cmd_len = scsi_req(req)->cmd_len;
- cmd->cmnd = scsi_req(req)->cmd;
- cmd->transfersize = blk_rq_bytes(req);
- cmd->allowed = scsi_req(req)->retries;
- return BLK_STS_OK;
- }
- static blk_status_t
- scsi_device_state_check(struct scsi_device *sdev, struct request *req)
- {
- switch (sdev->sdev_state) {
- case SDEV_CREATED:
- return BLK_STS_OK;
- case SDEV_OFFLINE:
- case SDEV_TRANSPORT_OFFLINE:
- /*
- * If the device is offline we refuse to process any
- * commands. The device must be brought online
- * before trying any recovery commands.
- */
- if (!sdev->offline_already) {
- sdev->offline_already = true;
- sdev_printk(KERN_ERR, sdev,
- "rejecting I/O to offline device\n");
- }
- return BLK_STS_IOERR;
- case SDEV_DEL:
- /*
- * If the device is fully deleted, we refuse to
- * process any commands as well.
- */
- sdev_printk(KERN_ERR, sdev,
- "rejecting I/O to dead device\n");
- return BLK_STS_IOERR;
- case SDEV_BLOCK:
- case SDEV_CREATED_BLOCK:
- return BLK_STS_RESOURCE;
- case SDEV_QUIESCE:
- /*
- * If the device is blocked we only accept power management
- * commands.
- */
- if (req && WARN_ON_ONCE(!(req->rq_flags & RQF_PM)))
- return BLK_STS_RESOURCE;
- return BLK_STS_OK;
- default:
- /*
- * For any other not fully online state we only allow
- * power management commands.
- */
- if (req && !(req->rq_flags & RQF_PM))
- return BLK_STS_IOERR;
- return BLK_STS_OK;
- }
- }
- /*
- * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
- * return 0.
- *
- * Called with the queue_lock held.
- */
- static inline int scsi_dev_queue_ready(struct request_queue *q,
- struct scsi_device *sdev)
- {
- unsigned int busy;
- busy = atomic_inc_return(&sdev->device_busy) - 1;
- if (atomic_read(&sdev->device_blocked)) {
- if (busy)
- goto out_dec;
- /*
- * unblock after device_blocked iterates to zero
- */
- if (atomic_dec_return(&sdev->device_blocked) > 0)
- goto out_dec;
- SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
- "unblocking device at zero depth\n"));
- }
- if (busy >= sdev->queue_depth)
- goto out_dec;
- return 1;
- out_dec:
- atomic_dec(&sdev->device_busy);
- return 0;
- }
- /*
- * scsi_target_queue_ready: checks if there we can send commands to target
- * @sdev: scsi device on starget to check.
- */
- static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
- struct scsi_device *sdev)
- {
- struct scsi_target *starget = scsi_target(sdev);
- unsigned int busy;
- if (starget->single_lun) {
- spin_lock_irq(shost->host_lock);
- if (starget->starget_sdev_user &&
- starget->starget_sdev_user != sdev) {
- spin_unlock_irq(shost->host_lock);
- return 0;
- }
- starget->starget_sdev_user = sdev;
- spin_unlock_irq(shost->host_lock);
- }
- if (starget->can_queue <= 0)
- return 1;
- busy = atomic_inc_return(&starget->target_busy) - 1;
- if (atomic_read(&starget->target_blocked) > 0) {
- if (busy)
- goto starved;
- /*
- * unblock after target_blocked iterates to zero
- */
- if (atomic_dec_return(&starget->target_blocked) > 0)
- goto out_dec;
- SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
- "unblocking target at zero depth\n"));
- }
- if (busy >= starget->can_queue)
- goto starved;
- return 1;
- starved:
- spin_lock_irq(shost->host_lock);
- list_move_tail(&sdev->starved_entry, &shost->starved_list);
- spin_unlock_irq(shost->host_lock);
- out_dec:
- if (starget->can_queue > 0)
- atomic_dec(&starget->target_busy);
- return 0;
- }
- /*
- * scsi_host_queue_ready: if we can send requests to shost, return 1 else
- * return 0. We must end up running the queue again whenever 0 is
- * returned, else IO can hang.
- */
- static inline int scsi_host_queue_ready(struct request_queue *q,
- struct Scsi_Host *shost,
- struct scsi_device *sdev,
- struct scsi_cmnd *cmd)
- {
- if (scsi_host_in_recovery(shost))
- return 0;
- if (atomic_read(&shost->host_blocked) > 0) {
- if (scsi_host_busy(shost) > 0)
- goto starved;
- /*
- * unblock after host_blocked iterates to zero
- */
- if (atomic_dec_return(&shost->host_blocked) > 0)
- goto out_dec;
- SCSI_LOG_MLQUEUE(3,
- shost_printk(KERN_INFO, shost,
- "unblocking host at zero depth\n"));
- }
- if (shost->host_self_blocked)
- goto starved;
- /* We're OK to process the command, so we can't be starved */
- if (!list_empty(&sdev->starved_entry)) {
- spin_lock_irq(shost->host_lock);
- if (!list_empty(&sdev->starved_entry))
- list_del_init(&sdev->starved_entry);
- spin_unlock_irq(shost->host_lock);
- }
- __set_bit(SCMD_STATE_INFLIGHT, &cmd->state);
- return 1;
- starved:
- spin_lock_irq(shost->host_lock);
- if (list_empty(&sdev->starved_entry))
- list_add_tail(&sdev->starved_entry, &shost->starved_list);
- spin_unlock_irq(shost->host_lock);
- out_dec:
- scsi_dec_host_busy(shost, cmd);
- return 0;
- }
- /*
- * Busy state exporting function for request stacking drivers.
- *
- * For efficiency, no lock is taken to check the busy state of
- * shost/starget/sdev, since the returned value is not guaranteed and
- * may be changed after request stacking drivers call the function,
- * regardless of taking lock or not.
- *
- * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
- * needs to return 'not busy'. Otherwise, request stacking drivers
- * may hold requests forever.
- */
- static bool scsi_mq_lld_busy(struct request_queue *q)
- {
- struct scsi_device *sdev = q->queuedata;
- struct Scsi_Host *shost;
- if (blk_queue_dying(q))
- return false;
- shost = sdev->host;
- /*
- * Ignore host/starget busy state.
- * Since block layer does not have a concept of fairness across
- * multiple queues, congestion of host/starget needs to be handled
- * in SCSI layer.
- */
- if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
- return true;
- return false;
- }
- static void scsi_softirq_done(struct request *rq)
- {
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- int disposition;
- INIT_LIST_HEAD(&cmd->eh_entry);
- atomic_inc(&cmd->device->iodone_cnt);
- if (cmd->result)
- atomic_inc(&cmd->device->ioerr_cnt);
- disposition = scsi_decide_disposition(cmd);
- if (disposition != SUCCESS && scsi_cmd_runtime_exceeced(cmd))
- disposition = SUCCESS;
- scsi_log_completion(cmd, disposition);
- switch (disposition) {
- case SUCCESS:
- scsi_finish_command(cmd);
- break;
- case NEEDS_RETRY:
- scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
- break;
- case ADD_TO_MLQUEUE:
- scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
- break;
- default:
- scsi_eh_scmd_add(cmd);
- break;
- }
- }
- /**
- * scsi_dispatch_command - Dispatch a command to the low-level driver.
- * @cmd: command block we are dispatching.
- *
- * Return: nonzero return request was rejected and device's queue needs to be
- * plugged.
- */
- static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
- {
- struct Scsi_Host *host = cmd->device->host;
- int rtn = 0;
- atomic_inc(&cmd->device->iorequest_cnt);
- /* check if the device is still usable */
- if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
- /* in SDEV_DEL we error all commands. DID_NO_CONNECT
- * returns an immediate error upwards, and signals
- * that the device is no longer present */
- cmd->result = DID_NO_CONNECT << 16;
- goto done;
- }
- /* Check to see if the scsi lld made this device blocked. */
- if (unlikely(scsi_device_blocked(cmd->device))) {
- /*
- * in blocked state, the command is just put back on
- * the device queue. The suspend state has already
- * blocked the queue so future requests should not
- * occur until the device transitions out of the
- * suspend state.
- */
- SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
- "queuecommand : device blocked\n"));
- return SCSI_MLQUEUE_DEVICE_BUSY;
- }
- /* Store the LUN value in cmnd, if needed. */
- if (cmd->device->lun_in_cdb)
- cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
- (cmd->device->lun << 5 & 0xe0);
- scsi_log_send(cmd);
- /*
- * Before we queue this command, check if the command
- * length exceeds what the host adapter can handle.
- */
- if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
- SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
- "queuecommand : command too long. "
- "cdb_size=%d host->max_cmd_len=%d\n",
- cmd->cmd_len, cmd->device->host->max_cmd_len));
- cmd->result = (DID_ABORT << 16);
- goto done;
- }
- if (unlikely(host->shost_state == SHOST_DEL)) {
- cmd->result = (DID_NO_CONNECT << 16);
- goto done;
- }
- trace_scsi_dispatch_cmd_start(cmd);
- rtn = host->hostt->queuecommand(host, cmd);
- if (rtn) {
- trace_scsi_dispatch_cmd_error(cmd, rtn);
- if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
- rtn != SCSI_MLQUEUE_TARGET_BUSY)
- rtn = SCSI_MLQUEUE_HOST_BUSY;
- SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
- "queuecommand : request rejected\n"));
- }
- return rtn;
- done:
- cmd->scsi_done(cmd);
- return 0;
- }
- /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */
- static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost)
- {
- return min_t(unsigned int, shost->sg_tablesize, SCSI_INLINE_SG_CNT) *
- sizeof(struct scatterlist);
- }
- static blk_status_t scsi_prepare_cmd(struct request *req)
- {
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
- struct scsi_device *sdev = req->q->queuedata;
- struct Scsi_Host *shost = sdev->host;
- struct scatterlist *sg;
- scsi_init_command(sdev, cmd);
- cmd->request = req;
- cmd->tag = req->tag;
- cmd->prot_op = SCSI_PROT_NORMAL;
- if (blk_rq_bytes(req))
- cmd->sc_data_direction = rq_dma_dir(req);
- else
- cmd->sc_data_direction = DMA_NONE;
- sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
- cmd->sdb.table.sgl = sg;
- if (scsi_host_get_prot(shost)) {
- memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
- cmd->prot_sdb->table.sgl =
- (struct scatterlist *)(cmd->prot_sdb + 1);
- }
- /*
- * Special handling for passthrough commands, which don't go to the ULP
- * at all:
- */
- if (blk_rq_is_scsi(req))
- return scsi_setup_scsi_cmnd(sdev, req);
- if (sdev->handler && sdev->handler->prep_fn) {
- blk_status_t ret = sdev->handler->prep_fn(sdev, req);
- if (ret != BLK_STS_OK)
- return ret;
- }
- cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd;
- memset(cmd->cmnd, 0, BLK_MAX_CDB);
- return scsi_cmd_to_driver(cmd)->init_command(cmd);
- }
- static void scsi_mq_done(struct scsi_cmnd *cmd)
- {
- if (unlikely(blk_should_fake_timeout(cmd->request->q)))
- return;
- if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state)))
- return;
- trace_scsi_dispatch_cmd_done(cmd);
- blk_mq_complete_request(cmd->request);
- }
- static void scsi_mq_put_budget(struct request_queue *q)
- {
- struct scsi_device *sdev = q->queuedata;
- atomic_dec(&sdev->device_busy);
- }
- static bool scsi_mq_get_budget(struct request_queue *q)
- {
- struct scsi_device *sdev = q->queuedata;
- if (scsi_dev_queue_ready(q, sdev))
- return true;
- atomic_inc(&sdev->restarts);
- /*
- * Orders atomic_inc(&sdev->restarts) and atomic_read(&sdev->device_busy).
- * .restarts must be incremented before .device_busy is read because the
- * code in scsi_run_queue_async() depends on the order of these operations.
- */
- smp_mb__after_atomic();
- /*
- * If all in-flight requests originated from this LUN are completed
- * before reading .device_busy, sdev->device_busy will be observed as
- * zero, then blk_mq_delay_run_hw_queues() will dispatch this request
- * soon. Otherwise, completion of one of these requests will observe
- * the .restarts flag, and the request queue will be run for handling
- * this request, see scsi_end_request().
- */
- if (unlikely(atomic_read(&sdev->device_busy) == 0 &&
- !scsi_device_blocked(sdev)))
- blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY);
- return false;
- }
- static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
- const struct blk_mq_queue_data *bd)
- {
- struct request *req = bd->rq;
- struct request_queue *q = req->q;
- struct scsi_device *sdev = q->queuedata;
- struct Scsi_Host *shost = sdev->host;
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
- blk_status_t ret;
- int reason;
- /*
- * If the device is not in running state we will reject some or all
- * commands.
- */
- if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
- ret = scsi_device_state_check(sdev, req);
- if (ret != BLK_STS_OK)
- goto out_put_budget;
- }
- ret = BLK_STS_RESOURCE;
- if (!scsi_target_queue_ready(shost, sdev))
- goto out_put_budget;
- if (!scsi_host_queue_ready(q, shost, sdev, cmd))
- goto out_dec_target_busy;
- if (!(req->rq_flags & RQF_DONTPREP)) {
- ret = scsi_prepare_cmd(req);
- if (ret != BLK_STS_OK)
- goto out_dec_host_busy;
- req->rq_flags |= RQF_DONTPREP;
- } else {
- clear_bit(SCMD_STATE_COMPLETE, &cmd->state);
- }
- cmd->flags &= SCMD_PRESERVED_FLAGS;
- if (sdev->simple_tags)
- cmd->flags |= SCMD_TAGGED;
- if (bd->last)
- cmd->flags |= SCMD_LAST;
- scsi_set_resid(cmd, 0);
- memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
- cmd->scsi_done = scsi_mq_done;
- blk_mq_start_request(req);
- reason = scsi_dispatch_cmd(cmd);
- if (reason) {
- scsi_set_blocked(cmd, reason);
- ret = BLK_STS_RESOURCE;
- goto out_dec_host_busy;
- }
- return BLK_STS_OK;
- out_dec_host_busy:
- scsi_dec_host_busy(shost, cmd);
- out_dec_target_busy:
- if (scsi_target(sdev)->can_queue > 0)
- atomic_dec(&scsi_target(sdev)->target_busy);
- out_put_budget:
- scsi_mq_put_budget(q);
- switch (ret) {
- case BLK_STS_OK:
- break;
- case BLK_STS_RESOURCE:
- case BLK_STS_ZONE_RESOURCE:
- if (scsi_device_blocked(sdev))
- ret = BLK_STS_DEV_RESOURCE;
- break;
- default:
- if (unlikely(!scsi_device_online(sdev)))
- scsi_req(req)->result = DID_NO_CONNECT << 16;
- else
- scsi_req(req)->result = DID_ERROR << 16;
- /*
- * Make sure to release all allocated resources when
- * we hit an error, as we will never see this command
- * again.
- */
- if (req->rq_flags & RQF_DONTPREP)
- scsi_mq_uninit_cmd(cmd);
- scsi_run_queue_async(sdev);
- break;
- }
- return ret;
- }
- static enum blk_eh_timer_return scsi_timeout(struct request *req,
- bool reserved)
- {
- if (reserved)
- return BLK_EH_RESET_TIMER;
- return scsi_times_out(req);
- }
- static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
- unsigned int hctx_idx, unsigned int numa_node)
- {
- struct Scsi_Host *shost = set->driver_data;
- const bool unchecked_isa_dma = shost->unchecked_isa_dma;
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- struct scatterlist *sg;
- int ret = 0;
- if (unchecked_isa_dma)
- cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
- cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma,
- GFP_KERNEL, numa_node);
- if (!cmd->sense_buffer)
- return -ENOMEM;
- cmd->req.sense = cmd->sense_buffer;
- if (scsi_host_get_prot(shost)) {
- sg = (void *)cmd + sizeof(struct scsi_cmnd) +
- shost->hostt->cmd_size;
- cmd->prot_sdb = (void *)sg + scsi_mq_inline_sgl_size(shost);
- }
- if (shost->hostt->init_cmd_priv) {
- ret = shost->hostt->init_cmd_priv(shost, cmd);
- if (ret < 0)
- scsi_free_sense_buffer(unchecked_isa_dma,
- cmd->sense_buffer);
- }
- return ret;
- }
- static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq,
- unsigned int hctx_idx)
- {
- struct Scsi_Host *shost = set->driver_data;
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- if (shost->hostt->exit_cmd_priv)
- shost->hostt->exit_cmd_priv(shost, cmd);
- scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
- cmd->sense_buffer);
- }
- static int scsi_map_queues(struct blk_mq_tag_set *set)
- {
- struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set);
- if (shost->hostt->map_queues)
- return shost->hostt->map_queues(shost);
- return blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
- }
- void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
- {
- struct device *dev = shost->dma_dev;
- /*
- * this limit is imposed by hardware restrictions
- */
- blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize,
- SG_MAX_SEGMENTS));
- if (scsi_host_prot_dma(shost)) {
- shost->sg_prot_tablesize =
- min_not_zero(shost->sg_prot_tablesize,
- (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS);
- BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize);
- blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
- }
- if (dev->dma_mask) {
- shost->max_sectors = min_t(unsigned int, shost->max_sectors,
- dma_max_mapping_size(dev) >> SECTOR_SHIFT);
- }
- blk_queue_max_hw_sectors(q, shost->max_sectors);
- if (shost->unchecked_isa_dma)
- blk_queue_bounce_limit(q, BLK_BOUNCE_ISA);
- blk_queue_segment_boundary(q, shost->dma_boundary);
- dma_set_seg_boundary(dev, shost->dma_boundary);
- blk_queue_max_segment_size(q, shost->max_segment_size);
- blk_queue_virt_boundary(q, shost->virt_boundary_mask);
- dma_set_max_seg_size(dev, queue_max_segment_size(q));
- /*
- * Set a reasonable default alignment: The larger of 32-byte (dword),
- * which is a common minimum for HBAs, and the minimum DMA alignment,
- * which is set by the platform.
- *
- * Devices that require a bigger alignment can increase it later.
- */
- blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1);
- }
- EXPORT_SYMBOL_GPL(__scsi_init_queue);
- static const struct blk_mq_ops scsi_mq_ops_no_commit = {
- .get_budget = scsi_mq_get_budget,
- .put_budget = scsi_mq_put_budget,
- .queue_rq = scsi_queue_rq,
- .complete = scsi_softirq_done,
- .timeout = scsi_timeout,
- #ifdef CONFIG_BLK_DEBUG_FS
- .show_rq = scsi_show_rq,
- #endif
- .init_request = scsi_mq_init_request,
- .exit_request = scsi_mq_exit_request,
- .initialize_rq_fn = scsi_initialize_rq,
- .cleanup_rq = scsi_cleanup_rq,
- .busy = scsi_mq_lld_busy,
- .map_queues = scsi_map_queues,
- };
- static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx)
- {
- struct request_queue *q = hctx->queue;
- struct scsi_device *sdev = q->queuedata;
- struct Scsi_Host *shost = sdev->host;
- shost->hostt->commit_rqs(shost, hctx->queue_num);
- }
- static const struct blk_mq_ops scsi_mq_ops = {
- .get_budget = scsi_mq_get_budget,
- .put_budget = scsi_mq_put_budget,
- .queue_rq = scsi_queue_rq,
- .commit_rqs = scsi_commit_rqs,
- .complete = scsi_softirq_done,
- .timeout = scsi_timeout,
- #ifdef CONFIG_BLK_DEBUG_FS
- .show_rq = scsi_show_rq,
- #endif
- .init_request = scsi_mq_init_request,
- .exit_request = scsi_mq_exit_request,
- .initialize_rq_fn = scsi_initialize_rq,
- .cleanup_rq = scsi_cleanup_rq,
- .busy = scsi_mq_lld_busy,
- .map_queues = scsi_map_queues,
- };
- struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev)
- {
- sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set);
- if (IS_ERR(sdev->request_queue))
- return NULL;
- sdev->request_queue->queuedata = sdev;
- __scsi_init_queue(sdev->host, sdev->request_queue);
- blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, sdev->request_queue);
- return sdev->request_queue;
- }
- int scsi_mq_setup_tags(struct Scsi_Host *shost)
- {
- unsigned int cmd_size, sgl_size;
- struct blk_mq_tag_set *tag_set = &shost->tag_set;
- sgl_size = max_t(unsigned int, sizeof(struct scatterlist),
- scsi_mq_inline_sgl_size(shost));
- cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size;
- if (scsi_host_get_prot(shost))
- cmd_size += sizeof(struct scsi_data_buffer) +
- sizeof(struct scatterlist) * SCSI_INLINE_PROT_SG_CNT;
- memset(tag_set, 0, sizeof(*tag_set));
- if (shost->hostt->commit_rqs)
- tag_set->ops = &scsi_mq_ops;
- else
- tag_set->ops = &scsi_mq_ops_no_commit;
- tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1;
- tag_set->queue_depth = shost->can_queue;
- tag_set->cmd_size = cmd_size;
- tag_set->numa_node = NUMA_NO_NODE;
- tag_set->flags = BLK_MQ_F_SHOULD_MERGE;
- tag_set->flags |=
- BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
- tag_set->driver_data = shost;
- if (shost->host_tagset)
- tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED;
- return blk_mq_alloc_tag_set(tag_set);
- }
- void scsi_mq_destroy_tags(struct Scsi_Host *shost)
- {
- blk_mq_free_tag_set(&shost->tag_set);
- }
- /**
- * scsi_device_from_queue - return sdev associated with a request_queue
- * @q: The request queue to return the sdev from
- *
- * Return the sdev associated with a request queue or NULL if the
- * request_queue does not reference a SCSI device.
- */
- struct scsi_device *scsi_device_from_queue(struct request_queue *q)
- {
- struct scsi_device *sdev = NULL;
- if (q->mq_ops == &scsi_mq_ops_no_commit ||
- q->mq_ops == &scsi_mq_ops)
- sdev = q->queuedata;
- if (!sdev || !get_device(&sdev->sdev_gendev))
- sdev = NULL;
- return sdev;
- }
- /**
- * scsi_block_requests - Utility function used by low-level drivers to prevent
- * further commands from being queued to the device.
- * @shost: host in question
- *
- * There is no timer nor any other means by which the requests get unblocked
- * other than the low-level driver calling scsi_unblock_requests().
- */
- void scsi_block_requests(struct Scsi_Host *shost)
- {
- shost->host_self_blocked = 1;
- }
- EXPORT_SYMBOL(scsi_block_requests);
- /**
- * scsi_unblock_requests - Utility function used by low-level drivers to allow
- * further commands to be queued to the device.
- * @shost: host in question
- *
- * There is no timer nor any other means by which the requests get unblocked
- * other than the low-level driver calling scsi_unblock_requests(). This is done
- * as an API function so that changes to the internals of the scsi mid-layer
- * won't require wholesale changes to drivers that use this feature.
- */
- void scsi_unblock_requests(struct Scsi_Host *shost)
- {
- shost->host_self_blocked = 0;
- scsi_run_host_queues(shost);
- }
- EXPORT_SYMBOL(scsi_unblock_requests);
- void scsi_exit_queue(void)
- {
- kmem_cache_destroy(scsi_sense_cache);
- kmem_cache_destroy(scsi_sense_isadma_cache);
- }
- /**
- * scsi_mode_select - issue a mode select
- * @sdev: SCSI device to be queried
- * @pf: Page format bit (1 == standard, 0 == vendor specific)
- * @sp: Save page bit (0 == don't save, 1 == save)
- * @modepage: mode page being requested
- * @buffer: request buffer (may not be smaller than eight bytes)
- * @len: length of request buffer.
- * @timeout: command timeout
- * @retries: number of retries before failing
- * @data: returns a structure abstracting the mode header data
- * @sshdr: place to put sense data (or NULL if no sense to be collected).
- * must be SCSI_SENSE_BUFFERSIZE big.
- *
- * Returns zero if successful; negative error number or scsi
- * status on error
- *
- */
- int
- scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
- unsigned char *buffer, int len, int timeout, int retries,
- struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
- {
- unsigned char cmd[10];
- unsigned char *real_buffer;
- int ret;
- memset(cmd, 0, sizeof(cmd));
- cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
- if (sdev->use_10_for_ms) {
- if (len > 65535)
- return -EINVAL;
- real_buffer = kmalloc(8 + len, GFP_KERNEL);
- if (!real_buffer)
- return -ENOMEM;
- memcpy(real_buffer + 8, buffer, len);
- len += 8;
- real_buffer[0] = 0;
- real_buffer[1] = 0;
- real_buffer[2] = data->medium_type;
- real_buffer[3] = data->device_specific;
- real_buffer[4] = data->longlba ? 0x01 : 0;
- real_buffer[5] = 0;
- real_buffer[6] = data->block_descriptor_length >> 8;
- real_buffer[7] = data->block_descriptor_length;
- cmd[0] = MODE_SELECT_10;
- cmd[7] = len >> 8;
- cmd[8] = len;
- } else {
- if (len > 255 || data->block_descriptor_length > 255 ||
- data->longlba)
- return -EINVAL;
- real_buffer = kmalloc(4 + len, GFP_KERNEL);
- if (!real_buffer)
- return -ENOMEM;
- memcpy(real_buffer + 4, buffer, len);
- len += 4;
- real_buffer[0] = 0;
- real_buffer[1] = data->medium_type;
- real_buffer[2] = data->device_specific;
- real_buffer[3] = data->block_descriptor_length;
- cmd[0] = MODE_SELECT;
- cmd[4] = len;
- }
- ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
- sshdr, timeout, retries, NULL);
- kfree(real_buffer);
- return ret;
- }
- EXPORT_SYMBOL_GPL(scsi_mode_select);
- /**
- * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
- * @sdev: SCSI device to be queried
- * @dbd: set if mode sense will allow block descriptors to be returned
- * @modepage: mode page being requested
- * @buffer: request buffer (may not be smaller than eight bytes)
- * @len: length of request buffer.
- * @timeout: command timeout
- * @retries: number of retries before failing
- * @data: returns a structure abstracting the mode header data
- * @sshdr: place to put sense data (or NULL if no sense to be collected).
- * must be SCSI_SENSE_BUFFERSIZE big.
- *
- * Returns zero if successful, or a negative error number on failure
- */
- int
- scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
- unsigned char *buffer, int len, int timeout, int retries,
- struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
- {
- unsigned char cmd[12];
- int use_10_for_ms;
- int header_length;
- int result, retry_count = retries;
- struct scsi_sense_hdr my_sshdr;
- memset(data, 0, sizeof(*data));
- memset(&cmd[0], 0, 12);
- dbd = sdev->set_dbd_for_ms ? 8 : dbd;
- cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */
- cmd[2] = modepage;
- /* caller might not be interested in sense, but we need it */
- if (!sshdr)
- sshdr = &my_sshdr;
- retry:
- use_10_for_ms = sdev->use_10_for_ms;
- if (use_10_for_ms) {
- if (len < 8)
- len = 8;
- cmd[0] = MODE_SENSE_10;
- cmd[8] = len;
- header_length = 8;
- } else {
- if (len < 4)
- len = 4;
- cmd[0] = MODE_SENSE;
- cmd[4] = len;
- header_length = 4;
- }
- memset(buffer, 0, len);
- result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
- sshdr, timeout, retries, NULL);
- if (result < 0)
- return result;
- /* This code looks awful: what it's doing is making sure an
- * ILLEGAL REQUEST sense return identifies the actual command
- * byte as the problem. MODE_SENSE commands can return
- * ILLEGAL REQUEST if the code page isn't supported */
- if (use_10_for_ms && !scsi_status_is_good(result) &&
- driver_byte(result) == DRIVER_SENSE) {
- if (scsi_sense_valid(sshdr)) {
- if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
- (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
- /*
- * Invalid command operation code
- */
- sdev->use_10_for_ms = 0;
- goto retry;
- }
- }
- }
- if (scsi_status_is_good(result)) {
- if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
- (modepage == 6 || modepage == 8))) {
- /* Initio breakage? */
- header_length = 0;
- data->length = 13;
- data->medium_type = 0;
- data->device_specific = 0;
- data->longlba = 0;
- data->block_descriptor_length = 0;
- } else if (use_10_for_ms) {
- data->length = buffer[0]*256 + buffer[1] + 2;
- data->medium_type = buffer[2];
- data->device_specific = buffer[3];
- data->longlba = buffer[4] & 0x01;
- data->block_descriptor_length = buffer[6]*256
- + buffer[7];
- } else {
- data->length = buffer[0] + 1;
- data->medium_type = buffer[1];
- data->device_specific = buffer[2];
- data->block_descriptor_length = buffer[3];
- }
- data->header_length = header_length;
- result = 0;
- } else if ((status_byte(result) == CHECK_CONDITION) &&
- scsi_sense_valid(sshdr) &&
- sshdr->sense_key == UNIT_ATTENTION && retry_count) {
- retry_count--;
- goto retry;
- }
- if (result > 0)
- result = -EIO;
- return result;
- }
- EXPORT_SYMBOL(scsi_mode_sense);
- /**
- * scsi_test_unit_ready - test if unit is ready
- * @sdev: scsi device to change the state of.
- * @timeout: command timeout
- * @retries: number of retries before failing
- * @sshdr: outpout pointer for decoded sense information.
- *
- * Returns zero if unsuccessful or an error if TUR failed. For
- * removable media, UNIT_ATTENTION sets ->changed flag.
- **/
- int
- scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
- struct scsi_sense_hdr *sshdr)
- {
- char cmd[] = {
- TEST_UNIT_READY, 0, 0, 0, 0, 0,
- };
- int result;
- /* try to eat the UNIT_ATTENTION if there are enough retries */
- do {
- result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
- timeout, 1, NULL);
- if (sdev->removable && scsi_sense_valid(sshdr) &&
- sshdr->sense_key == UNIT_ATTENTION)
- sdev->changed = 1;
- } while (scsi_sense_valid(sshdr) &&
- sshdr->sense_key == UNIT_ATTENTION && --retries);
- return result;
- }
- EXPORT_SYMBOL(scsi_test_unit_ready);
- /**
- * scsi_device_set_state - Take the given device through the device state model.
- * @sdev: scsi device to change the state of.
- * @state: state to change to.
- *
- * Returns zero if successful or an error if the requested
- * transition is illegal.
- */
- int
- scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
- {
- enum scsi_device_state oldstate = sdev->sdev_state;
- if (state == oldstate)
- return 0;
- switch (state) {
- case SDEV_CREATED:
- switch (oldstate) {
- case SDEV_CREATED_BLOCK:
- break;
- default:
- goto illegal;
- }
- break;
- case SDEV_RUNNING:
- switch (oldstate) {
- case SDEV_CREATED:
- case SDEV_OFFLINE:
- case SDEV_TRANSPORT_OFFLINE:
- case SDEV_QUIESCE:
- case SDEV_BLOCK:
- break;
- default:
- goto illegal;
- }
- break;
- case SDEV_QUIESCE:
- switch (oldstate) {
- case SDEV_RUNNING:
- case SDEV_OFFLINE:
- case SDEV_TRANSPORT_OFFLINE:
- break;
- default:
- goto illegal;
- }
- break;
- case SDEV_OFFLINE:
- case SDEV_TRANSPORT_OFFLINE:
- switch (oldstate) {
- case SDEV_CREATED:
- case SDEV_RUNNING:
- case SDEV_QUIESCE:
- case SDEV_BLOCK:
- break;
- default:
- goto illegal;
- }
- break;
- case SDEV_BLOCK:
- switch (oldstate) {
- case SDEV_RUNNING:
- case SDEV_CREATED_BLOCK:
- case SDEV_QUIESCE:
- case SDEV_OFFLINE:
- break;
- default:
- goto illegal;
- }
- break;
- case SDEV_CREATED_BLOCK:
- switch (oldstate) {
- case SDEV_CREATED:
- break;
- default:
- goto illegal;
- }
- break;
- case SDEV_CANCEL:
- switch (oldstate) {
- case SDEV_CREATED:
- case SDEV_RUNNING:
- case SDEV_QUIESCE:
- case SDEV_OFFLINE:
- case SDEV_TRANSPORT_OFFLINE:
- break;
- default:
- goto illegal;
- }
- break;
- case SDEV_DEL:
- switch (oldstate) {
- case SDEV_CREATED:
- case SDEV_RUNNING:
- case SDEV_OFFLINE:
- case SDEV_TRANSPORT_OFFLINE:
- case SDEV_CANCEL:
- case SDEV_BLOCK:
- case SDEV_CREATED_BLOCK:
- break;
- default:
- goto illegal;
- }
- break;
- }
- sdev->offline_already = false;
- sdev->sdev_state = state;
- return 0;
- illegal:
- SCSI_LOG_ERROR_RECOVERY(1,
- sdev_printk(KERN_ERR, sdev,
- "Illegal state transition %s->%s",
- scsi_device_state_name(oldstate),
- scsi_device_state_name(state))
- );
- return -EINVAL;
- }
- EXPORT_SYMBOL(scsi_device_set_state);
- /**
- * sdev_evt_emit - emit a single SCSI device uevent
- * @sdev: associated SCSI device
- * @evt: event to emit
- *
- * Send a single uevent (scsi_event) to the associated scsi_device.
- */
- static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
- {
- int idx = 0;
- char *envp[3];
- switch (evt->evt_type) {
- case SDEV_EVT_MEDIA_CHANGE:
- envp[idx++] = "SDEV_MEDIA_CHANGE=1";
- break;
- case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
- scsi_rescan_device(&sdev->sdev_gendev);
- envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
- break;
- case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
- envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
- break;
- case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
- envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED";
- break;
- case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
- envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED";
- break;
- case SDEV_EVT_LUN_CHANGE_REPORTED:
- envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
- break;
- case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
- envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
- break;
- case SDEV_EVT_POWER_ON_RESET_OCCURRED:
- envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED";
- break;
- default:
- /* do nothing */
- break;
- }
- envp[idx++] = NULL;
- kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
- }
- /**
- * sdev_evt_thread - send a uevent for each scsi event
- * @work: work struct for scsi_device
- *
- * Dispatch queued events to their associated scsi_device kobjects
- * as uevents.
- */
- void scsi_evt_thread(struct work_struct *work)
- {
- struct scsi_device *sdev;
- enum scsi_device_event evt_type;
- LIST_HEAD(event_list);
- sdev = container_of(work, struct scsi_device, event_work);
- for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++)
- if (test_and_clear_bit(evt_type, sdev->pending_events))
- sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL);
- while (1) {
- struct scsi_event *evt;
- struct list_head *this, *tmp;
- unsigned long flags;
- spin_lock_irqsave(&sdev->list_lock, flags);
- list_splice_init(&sdev->event_list, &event_list);
- spin_unlock_irqrestore(&sdev->list_lock, flags);
- if (list_empty(&event_list))
- break;
- list_for_each_safe(this, tmp, &event_list) {
- evt = list_entry(this, struct scsi_event, node);
- list_del(&evt->node);
- scsi_evt_emit(sdev, evt);
- kfree(evt);
- }
- }
- }
- /**
- * sdev_evt_send - send asserted event to uevent thread
- * @sdev: scsi_device event occurred on
- * @evt: event to send
- *
- * Assert scsi device event asynchronously.
- */
- void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
- {
- unsigned long flags;
- #if 0
- /* FIXME: currently this check eliminates all media change events
- * for polled devices. Need to update to discriminate between AN
- * and polled events */
- if (!test_bit(evt->evt_type, sdev->supported_events)) {
- kfree(evt);
- return;
- }
- #endif
- spin_lock_irqsave(&sdev->list_lock, flags);
- list_add_tail(&evt->node, &sdev->event_list);
- schedule_work(&sdev->event_work);
- spin_unlock_irqrestore(&sdev->list_lock, flags);
- }
- EXPORT_SYMBOL_GPL(sdev_evt_send);
- /**
- * sdev_evt_alloc - allocate a new scsi event
- * @evt_type: type of event to allocate
- * @gfpflags: GFP flags for allocation
- *
- * Allocates and returns a new scsi_event.
- */
- struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
- gfp_t gfpflags)
- {
- struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
- if (!evt)
- return NULL;
- evt->evt_type = evt_type;
- INIT_LIST_HEAD(&evt->node);
- /* evt_type-specific initialization, if any */
- switch (evt_type) {
- case SDEV_EVT_MEDIA_CHANGE:
- case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
- case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
- case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
- case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
- case SDEV_EVT_LUN_CHANGE_REPORTED:
- case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
- case SDEV_EVT_POWER_ON_RESET_OCCURRED:
- default:
- /* do nothing */
- break;
- }
- return evt;
- }
- EXPORT_SYMBOL_GPL(sdev_evt_alloc);
- /**
- * sdev_evt_send_simple - send asserted event to uevent thread
- * @sdev: scsi_device event occurred on
- * @evt_type: type of event to send
- * @gfpflags: GFP flags for allocation
- *
- * Assert scsi device event asynchronously, given an event type.
- */
- void sdev_evt_send_simple(struct scsi_device *sdev,
- enum scsi_device_event evt_type, gfp_t gfpflags)
- {
- struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
- if (!evt) {
- sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
- evt_type);
- return;
- }
- sdev_evt_send(sdev, evt);
- }
- EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
- /**
- * scsi_device_quiesce - Block all commands except power management.
- * @sdev: scsi device to quiesce.
- *
- * This works by trying to transition to the SDEV_QUIESCE state
- * (which must be a legal transition). When the device is in this
- * state, only power management requests will be accepted, all others will
- * be deferred.
- *
- * Must be called with user context, may sleep.
- *
- * Returns zero if unsuccessful or an error if not.
- */
- int
- scsi_device_quiesce(struct scsi_device *sdev)
- {
- struct request_queue *q = sdev->request_queue;
- int err;
- /*
- * It is allowed to call scsi_device_quiesce() multiple times from
- * the same context but concurrent scsi_device_quiesce() calls are
- * not allowed.
- */
- WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current);
- if (sdev->quiesced_by == current)
- return 0;
- blk_set_pm_only(q);
- blk_mq_freeze_queue(q);
- /*
- * Ensure that the effect of blk_set_pm_only() will be visible
- * for percpu_ref_tryget() callers that occur after the queue
- * unfreeze even if the queue was already frozen before this function
- * was called. See also https://lwn.net/Articles/573497/.
- */
- synchronize_rcu();
- blk_mq_unfreeze_queue(q);
- mutex_lock(&sdev->state_mutex);
- err = scsi_device_set_state(sdev, SDEV_QUIESCE);
- if (err == 0)
- sdev->quiesced_by = current;
- else
- blk_clear_pm_only(q);
- mutex_unlock(&sdev->state_mutex);
- return err;
- }
- EXPORT_SYMBOL(scsi_device_quiesce);
- /**
- * scsi_device_resume - Restart user issued commands to a quiesced device.
- * @sdev: scsi device to resume.
- *
- * Moves the device from quiesced back to running and restarts the
- * queues.
- *
- * Must be called with user context, may sleep.
- */
- void scsi_device_resume(struct scsi_device *sdev)
- {
- /* check if the device state was mutated prior to resume, and if
- * so assume the state is being managed elsewhere (for example
- * device deleted during suspend)
- */
- mutex_lock(&sdev->state_mutex);
- if (sdev->sdev_state == SDEV_QUIESCE)
- scsi_device_set_state(sdev, SDEV_RUNNING);
- if (sdev->quiesced_by) {
- sdev->quiesced_by = NULL;
- blk_clear_pm_only(sdev->request_queue);
- }
- mutex_unlock(&sdev->state_mutex);
- }
- EXPORT_SYMBOL(scsi_device_resume);
- static void
- device_quiesce_fn(struct scsi_device *sdev, void *data)
- {
- scsi_device_quiesce(sdev);
- }
- void
- scsi_target_quiesce(struct scsi_target *starget)
- {
- starget_for_each_device(starget, NULL, device_quiesce_fn);
- }
- EXPORT_SYMBOL(scsi_target_quiesce);
- static void
- device_resume_fn(struct scsi_device *sdev, void *data)
- {
- scsi_device_resume(sdev);
- }
- void
- scsi_target_resume(struct scsi_target *starget)
- {
- starget_for_each_device(starget, NULL, device_resume_fn);
- }
- EXPORT_SYMBOL(scsi_target_resume);
- /**
- * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
- * @sdev: device to block
- *
- * Pause SCSI command processing on the specified device. Does not sleep.
- *
- * Returns zero if successful or a negative error code upon failure.
- *
- * Notes:
- * This routine transitions the device to the SDEV_BLOCK state (which must be
- * a legal transition). When the device is in this state, command processing
- * is paused until the device leaves the SDEV_BLOCK state. See also
- * scsi_internal_device_unblock_nowait().
- */
- int scsi_internal_device_block_nowait(struct scsi_device *sdev)
- {
- struct request_queue *q = sdev->request_queue;
- int err = 0;
- err = scsi_device_set_state(sdev, SDEV_BLOCK);
- if (err) {
- err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
- if (err)
- return err;
- }
- /*
- * The device has transitioned to SDEV_BLOCK. Stop the
- * block layer from calling the midlayer with this device's
- * request queue.
- */
- blk_mq_quiesce_queue_nowait(q);
- return 0;
- }
- EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
- /**
- * scsi_internal_device_block - try to transition to the SDEV_BLOCK state
- * @sdev: device to block
- *
- * Pause SCSI command processing on the specified device and wait until all
- * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep.
- *
- * Returns zero if successful or a negative error code upon failure.
- *
- * Note:
- * This routine transitions the device to the SDEV_BLOCK state (which must be
- * a legal transition). When the device is in this state, command processing
- * is paused until the device leaves the SDEV_BLOCK state. See also
- * scsi_internal_device_unblock().
- */
- static int scsi_internal_device_block(struct scsi_device *sdev)
- {
- struct request_queue *q = sdev->request_queue;
- int err;
- mutex_lock(&sdev->state_mutex);
- err = scsi_internal_device_block_nowait(sdev);
- if (err == 0)
- blk_mq_quiesce_queue(q);
- mutex_unlock(&sdev->state_mutex);
- return err;
- }
- void scsi_start_queue(struct scsi_device *sdev)
- {
- struct request_queue *q = sdev->request_queue;
- blk_mq_unquiesce_queue(q);
- }
- /**
- * scsi_internal_device_unblock_nowait - resume a device after a block request
- * @sdev: device to resume
- * @new_state: state to set the device to after unblocking
- *
- * Restart the device queue for a previously suspended SCSI device. Does not
- * sleep.
- *
- * Returns zero if successful or a negative error code upon failure.
- *
- * Notes:
- * This routine transitions the device to the SDEV_RUNNING state or to one of
- * the offline states (which must be a legal transition) allowing the midlayer
- * to goose the queue for this device.
- */
- int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
- enum scsi_device_state new_state)
- {
- switch (new_state) {
- case SDEV_RUNNING:
- case SDEV_TRANSPORT_OFFLINE:
- break;
- default:
- return -EINVAL;
- }
- /*
- * Try to transition the scsi device to SDEV_RUNNING or one of the
- * offlined states and goose the device queue if successful.
- */
- switch (sdev->sdev_state) {
- case SDEV_BLOCK:
- case SDEV_TRANSPORT_OFFLINE:
- sdev->sdev_state = new_state;
- break;
- case SDEV_CREATED_BLOCK:
- if (new_state == SDEV_TRANSPORT_OFFLINE ||
- new_state == SDEV_OFFLINE)
- sdev->sdev_state = new_state;
- else
- sdev->sdev_state = SDEV_CREATED;
- break;
- case SDEV_CANCEL:
- case SDEV_OFFLINE:
- break;
- default:
- return -EINVAL;
- }
- scsi_start_queue(sdev);
- return 0;
- }
- EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait);
- /**
- * scsi_internal_device_unblock - resume a device after a block request
- * @sdev: device to resume
- * @new_state: state to set the device to after unblocking
- *
- * Restart the device queue for a previously suspended SCSI device. May sleep.
- *
- * Returns zero if successful or a negative error code upon failure.
- *
- * Notes:
- * This routine transitions the device to the SDEV_RUNNING state or to one of
- * the offline states (which must be a legal transition) allowing the midlayer
- * to goose the queue for this device.
- */
- static int scsi_internal_device_unblock(struct scsi_device *sdev,
- enum scsi_device_state new_state)
- {
- int ret;
- mutex_lock(&sdev->state_mutex);
- ret = scsi_internal_device_unblock_nowait(sdev, new_state);
- mutex_unlock(&sdev->state_mutex);
- return ret;
- }
- static void
- device_block(struct scsi_device *sdev, void *data)
- {
- int ret;
- ret = scsi_internal_device_block(sdev);
- WARN_ONCE(ret, "scsi_internal_device_block(%s) failed: ret = %d\n",
- dev_name(&sdev->sdev_gendev), ret);
- }
- static int
- target_block(struct device *dev, void *data)
- {
- if (scsi_is_target_device(dev))
- starget_for_each_device(to_scsi_target(dev), NULL,
- device_block);
- return 0;
- }
- void
- scsi_target_block(struct device *dev)
- {
- if (scsi_is_target_device(dev))
- starget_for_each_device(to_scsi_target(dev), NULL,
- device_block);
- else
- device_for_each_child(dev, NULL, target_block);
- }
- EXPORT_SYMBOL_GPL(scsi_target_block);
- static void
- device_unblock(struct scsi_device *sdev, void *data)
- {
- scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
- }
- static int
- target_unblock(struct device *dev, void *data)
- {
- if (scsi_is_target_device(dev))
- starget_for_each_device(to_scsi_target(dev), data,
- device_unblock);
- return 0;
- }
- void
- scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
- {
- if (scsi_is_target_device(dev))
- starget_for_each_device(to_scsi_target(dev), &new_state,
- device_unblock);
- else
- device_for_each_child(dev, &new_state, target_unblock);
- }
- EXPORT_SYMBOL_GPL(scsi_target_unblock);
- int
- scsi_host_block(struct Scsi_Host *shost)
- {
- struct scsi_device *sdev;
- int ret = 0;
- /*
- * Call scsi_internal_device_block_nowait so we can avoid
- * calling synchronize_rcu() for each LUN.
- */
- shost_for_each_device(sdev, shost) {
- mutex_lock(&sdev->state_mutex);
- ret = scsi_internal_device_block_nowait(sdev);
- mutex_unlock(&sdev->state_mutex);
- if (ret) {
- scsi_device_put(sdev);
- break;
- }
- }
- /*
- * SCSI never enables blk-mq's BLK_MQ_F_BLOCKING flag so
- * calling synchronize_rcu() once is enough.
- */
- WARN_ON_ONCE(shost->tag_set.flags & BLK_MQ_F_BLOCKING);
- if (!ret)
- synchronize_rcu();
- return ret;
- }
- EXPORT_SYMBOL_GPL(scsi_host_block);
- int
- scsi_host_unblock(struct Scsi_Host *shost, int new_state)
- {
- struct scsi_device *sdev;
- int ret = 0;
- shost_for_each_device(sdev, shost) {
- ret = scsi_internal_device_unblock(sdev, new_state);
- if (ret) {
- scsi_device_put(sdev);
- break;
- }
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(scsi_host_unblock);
- /**
- * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
- * @sgl: scatter-gather list
- * @sg_count: number of segments in sg
- * @offset: offset in bytes into sg, on return offset into the mapped area
- * @len: bytes to map, on return number of bytes mapped
- *
- * Returns virtual address of the start of the mapped page
- */
- void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
- size_t *offset, size_t *len)
- {
- int i;
- size_t sg_len = 0, len_complete = 0;
- struct scatterlist *sg;
- struct page *page;
- WARN_ON(!irqs_disabled());
- for_each_sg(sgl, sg, sg_count, i) {
- len_complete = sg_len; /* Complete sg-entries */
- sg_len += sg->length;
- if (sg_len > *offset)
- break;
- }
- if (unlikely(i == sg_count)) {
- printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
- "elements %d\n",
- __func__, sg_len, *offset, sg_count);
- WARN_ON(1);
- return NULL;
- }
- /* Offset starting from the beginning of first page in this sg-entry */
- *offset = *offset - len_complete + sg->offset;
- /* Assumption: contiguous pages can be accessed as "page + i" */
- page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
- *offset &= ~PAGE_MASK;
- /* Bytes in this sg-entry from *offset to the end of the page */
- sg_len = PAGE_SIZE - *offset;
- if (*len > sg_len)
- *len = sg_len;
- return kmap_atomic(page);
- }
- EXPORT_SYMBOL(scsi_kmap_atomic_sg);
- /**
- * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
- * @virt: virtual address to be unmapped
- */
- void scsi_kunmap_atomic_sg(void *virt)
- {
- kunmap_atomic(virt);
- }
- EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
- void sdev_disable_disk_events(struct scsi_device *sdev)
- {
- atomic_inc(&sdev->disk_events_disable_depth);
- }
- EXPORT_SYMBOL(sdev_disable_disk_events);
- void sdev_enable_disk_events(struct scsi_device *sdev)
- {
- if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0))
- return;
- atomic_dec(&sdev->disk_events_disable_depth);
- }
- EXPORT_SYMBOL(sdev_enable_disk_events);
- static unsigned char designator_prio(const unsigned char *d)
- {
- if (d[1] & 0x30)
- /* not associated with LUN */
- return 0;
- if (d[3] == 0)
- /* invalid length */
- return 0;
- /*
- * Order of preference for lun descriptor:
- * - SCSI name string
- * - NAA IEEE Registered Extended
- * - EUI-64 based 16-byte
- * - EUI-64 based 12-byte
- * - NAA IEEE Registered
- * - NAA IEEE Extended
- * - EUI-64 based 8-byte
- * - SCSI name string (truncated)
- * - T10 Vendor ID
- * as longer descriptors reduce the likelyhood
- * of identification clashes.
- */
- switch (d[1] & 0xf) {
- case 8:
- /* SCSI name string, variable-length UTF-8 */
- return 9;
- case 3:
- switch (d[4] >> 4) {
- case 6:
- /* NAA registered extended */
- return 8;
- case 5:
- /* NAA registered */
- return 5;
- case 4:
- /* NAA extended */
- return 4;
- case 3:
- /* NAA locally assigned */
- return 1;
- default:
- break;
- }
- break;
- case 2:
- switch (d[3]) {
- case 16:
- /* EUI64-based, 16 byte */
- return 7;
- case 12:
- /* EUI64-based, 12 byte */
- return 6;
- case 8:
- /* EUI64-based, 8 byte */
- return 3;
- default:
- break;
- }
- break;
- case 1:
- /* T10 vendor ID */
- return 1;
- default:
- break;
- }
- return 0;
- }
- /**
- * scsi_vpd_lun_id - return a unique device identification
- * @sdev: SCSI device
- * @id: buffer for the identification
- * @id_len: length of the buffer
- *
- * Copies a unique device identification into @id based
- * on the information in the VPD page 0x83 of the device.
- * The string will be formatted as a SCSI name string.
- *
- * Returns the length of the identification or error on failure.
- * If the identifier is longer than the supplied buffer the actual
- * identifier length is returned and the buffer is not zero-padded.
- */
- int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
- {
- u8 cur_id_prio = 0;
- u8 cur_id_size = 0;
- const unsigned char *d, *cur_id_str;
- const struct scsi_vpd *vpd_pg83;
- int id_size = -EINVAL;
- rcu_read_lock();
- vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
- if (!vpd_pg83) {
- rcu_read_unlock();
- return -ENXIO;
- }
- /* The id string must be at least 20 bytes + terminating NULL byte */
- if (id_len < 21) {
- rcu_read_unlock();
- return -EINVAL;
- }
- memset(id, 0, id_len);
- d = vpd_pg83->data + 4;
- while (d < vpd_pg83->data + vpd_pg83->len) {
- u8 prio = designator_prio(d);
- if (prio == 0 || cur_id_prio > prio)
- goto next_desig;
- switch (d[1] & 0xf) {
- case 0x1:
- /* T10 Vendor ID */
- if (cur_id_size > d[3])
- break;
- cur_id_prio = prio;
- cur_id_size = d[3];
- if (cur_id_size + 4 > id_len)
- cur_id_size = id_len - 4;
- cur_id_str = d + 4;
- id_size = snprintf(id, id_len, "t10.%*pE",
- cur_id_size, cur_id_str);
- break;
- case 0x2:
- /* EUI-64 */
- cur_id_prio = prio;
- cur_id_size = d[3];
- cur_id_str = d + 4;
- switch (cur_id_size) {
- case 8:
- id_size = snprintf(id, id_len,
- "eui.%8phN",
- cur_id_str);
- break;
- case 12:
- id_size = snprintf(id, id_len,
- "eui.%12phN",
- cur_id_str);
- break;
- case 16:
- id_size = snprintf(id, id_len,
- "eui.%16phN",
- cur_id_str);
- break;
- default:
- break;
- }
- break;
- case 0x3:
- /* NAA */
- cur_id_prio = prio;
- cur_id_size = d[3];
- cur_id_str = d + 4;
- switch (cur_id_size) {
- case 8:
- id_size = snprintf(id, id_len,
- "naa.%8phN",
- cur_id_str);
- break;
- case 16:
- id_size = snprintf(id, id_len,
- "naa.%16phN",
- cur_id_str);
- break;
- default:
- break;
- }
- break;
- case 0x8:
- /* SCSI name string */
- if (cur_id_size > d[3])
- break;
- /* Prefer others for truncated descriptor */
- if (d[3] > id_len) {
- prio = 2;
- if (cur_id_prio > prio)
- break;
- }
- cur_id_prio = prio;
- cur_id_size = id_size = d[3];
- cur_id_str = d + 4;
- if (cur_id_size >= id_len)
- cur_id_size = id_len - 1;
- memcpy(id, cur_id_str, cur_id_size);
- break;
- default:
- break;
- }
- next_desig:
- d += d[3] + 4;
- }
- rcu_read_unlock();
- return id_size;
- }
- EXPORT_SYMBOL(scsi_vpd_lun_id);
- /*
- * scsi_vpd_tpg_id - return a target port group identifier
- * @sdev: SCSI device
- *
- * Returns the Target Port Group identifier from the information
- * froom VPD page 0x83 of the device.
- *
- * Returns the identifier or error on failure.
- */
- int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id)
- {
- const unsigned char *d;
- const struct scsi_vpd *vpd_pg83;
- int group_id = -EAGAIN, rel_port = -1;
- rcu_read_lock();
- vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
- if (!vpd_pg83) {
- rcu_read_unlock();
- return -ENXIO;
- }
- d = vpd_pg83->data + 4;
- while (d < vpd_pg83->data + vpd_pg83->len) {
- switch (d[1] & 0xf) {
- case 0x4:
- /* Relative target port */
- rel_port = get_unaligned_be16(&d[6]);
- break;
- case 0x5:
- /* Target port group */
- group_id = get_unaligned_be16(&d[6]);
- break;
- default:
- break;
- }
- d += d[3] + 4;
- }
- rcu_read_unlock();
- if (group_id >= 0 && rel_id && rel_port != -1)
- *rel_id = rel_port;
- return group_id;
- }
- EXPORT_SYMBOL(scsi_vpd_tpg_id);
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