| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Christoph Hellwig | 2700 | 22.42% | 115 | 21.10% |
| James Bottomley | 1710 | 14.20% | 62 | 11.38% |
| Hannes Reinecke | 892 | 7.41% | 28 | 5.14% |
| Bart Van Assche | 866 | 7.19% | 64 | 11.74% |
| Michael Christie | 856 | 7.11% | 22 | 4.04% |
| Jens Axboe | 825 | 6.85% | 22 | 4.04% |
| Douglas Gilbert | 552 | 4.58% | 15 | 2.75% |
| Ming Lei | 504 | 4.19% | 23 | 4.22% |
| Jeff Garzik | 348 | 2.89% | 1 | 0.18% |
| Martin Wilck | 250 | 2.08% | 8 | 1.47% |
| Linus Torvalds (pre-git) | 205 | 1.70% | 18 | 3.30% |
| Patrick Mansfield | 197 | 1.64% | 14 | 2.57% |
| Guennadi Liakhovetski | 166 | 1.38% | 1 | 0.18% |
| Martin K. Petersen | 164 | 1.36% | 12 | 2.20% |
| Ewan D. Milne | 145 | 1.20% | 4 | 0.73% |
| Damien Le Moal | 132 | 1.10% | 6 | 1.10% |
| Andrew Vasquez | 130 | 1.08% | 1 | 0.18% |
| Alan Stern | 117 | 0.97% | 5 | 0.92% |
| Kashyap Desai | 114 | 0.95% | 3 | 0.55% |
| Mike Anderson | 94 | 0.78% | 8 | 1.47% |
| James Smart | 92 | 0.76% | 2 | 0.37% |
| Paolo Bonzini | 92 | 0.76% | 1 | 0.18% |
| Kiyoshi Ueda | 84 | 0.70% | 2 | 0.37% |
| Wenchao Hao | 61 | 0.51% | 3 | 0.55% |
| Boaz Harrosh | 57 | 0.47% | 3 | 0.55% |
| Al Viro | 53 | 0.44% | 1 | 0.18% |
| Sebastian Andrzej Siewior | 49 | 0.41% | 1 | 0.18% |
| Aaron Lu | 49 | 0.41% | 1 | 0.18% |
| FUJITA Tomonori | 48 | 0.40% | 8 | 1.47% |
| Brian Bunker | 44 | 0.37% | 1 | 0.18% |
| Tejun Heo | 32 | 0.27% | 9 | 1.65% |
| Linus Torvalds | 28 | 0.23% | 9 | 1.65% |
| Jaesoo Lee | 27 | 0.22% | 1 | 0.18% |
| Chandra Seetharaman | 24 | 0.20% | 1 | 0.18% |
| Ye Bin | 24 | 0.20% | 3 | 0.55% |
| Ming Lin | 23 | 0.19% | 3 | 0.55% |
| Keith Busch | 21 | 0.17% | 2 | 0.37% |
| Takahiro Yasui | 16 | 0.13% | 1 | 0.18% |
| Eiichi Tsukata | 15 | 0.12% | 1 | 0.18% |
| Doug Ledford | 13 | 0.11% | 2 | 0.37% |
| Shaohua Li | 13 | 0.11% | 2 | 0.37% |
| Felix Beck | 12 | 0.10% | 1 | 0.18% |
| Niklas Svensson (Niklas Cassel) | 12 | 0.10% | 2 | 0.37% |
| Andries E. Brouwer | 11 | 0.09% | 2 | 0.37% |
| Can Guo | 10 | 0.08% | 1 | 0.18% |
| Brian King | 10 | 0.08% | 1 | 0.18% |
| David Howells | 9 | 0.07% | 1 | 0.18% |
| Andrew Morton | 9 | 0.07% | 2 | 0.37% |
| Steffen Maier | 7 | 0.06% | 1 | 0.18% |
| Kay Sievers | 7 | 0.06% | 1 | 0.18% |
| John Garry | 6 | 0.05% | 1 | 0.18% |
| Michael Schmitz | 6 | 0.05% | 1 | 0.18% |
| Bartlomiej Zolnierkiewicz | 6 | 0.05% | 2 | 0.37% |
| Alan Cox | 6 | 0.05% | 1 | 0.18% |
| Luben Tuikov | 6 | 0.05% | 2 | 0.37% |
| Mike Snitzer | 6 | 0.05% | 2 | 0.37% |
| Akinobu Mita | 5 | 0.04% | 1 | 0.18% |
| André Almeida | 5 | 0.04% | 1 | 0.18% |
| David Windsor | 5 | 0.04% | 1 | 0.18% |
| Quat Le | 4 | 0.03% | 1 | 0.18% |
| Tony Battersby | 4 | 0.03% | 1 | 0.18% |
| Jianchao Wang | 4 | 0.03% | 1 | 0.18% |
| Johannes Thumshirn | 4 | 0.03% | 1 | 0.18% |
| Muneendra Kumar M | 4 | 0.03% | 1 | 0.18% |
| Kristen Carlson Accardi | 4 | 0.03% | 1 | 0.18% |
| Maximilian Attems | 3 | 0.02% | 1 | 0.18% |
| Paul Gortmaker | 3 | 0.02% | 1 | 0.18% |
| Mauro Carvalho Chehab | 3 | 0.02% | 1 | 0.18% |
| Joe Lawrence | 3 | 0.02% | 1 | 0.18% |
| Geert Uytterhoeven | 3 | 0.02% | 1 | 0.18% |
| Dexuan Cui | 3 | 0.02% | 1 | 0.18% |
| Rusty Russell | 3 | 0.02% | 1 | 0.18% |
| Rob Landley | 3 | 0.02% | 1 | 0.18% |
| Keiichiro Tokunaga | 3 | 0.02% | 1 | 0.18% |
| Dan J Williams | 2 | 0.02% | 1 | 0.18% |
| Gustavo A. R. Silva | 2 | 0.02% | 1 | 0.18% |
| Adrian Bunk | 2 | 0.02% | 2 | 0.37% |
| Babu Moger | 2 | 0.02% | 1 | 0.18% |
| Dongli Zhang | 1 | 0.01% | 1 | 0.18% |
| Huacai Chen | 1 | 0.01% | 1 | 0.18% |
| Bean Huo | 1 | 0.01% | 1 | 0.18% |
| Matthew Wilcox | 1 | 0.01% | 1 | 0.18% |
| Song Liu | 1 | 0.01% | 1 | 0.18% |
| Lukas Bulwahn | 1 | 0.01% | 1 | 0.18% |
| Thomas Gleixner | 1 | 0.01% | 1 | 0.18% |
| Eric Biggers | 1 | 0.01% | 1 | 0.18% |
| Harvey Harrison | 1 | 0.01% | 1 | 0.18% |
| Vikas Chaudhary | 1 | 0.01% | 1 | 0.18% |
| Jun'ichi Nomura | 1 | 0.01% | 1 | 0.18% |
| Arjan van de Ven | 1 | 0.01% | 1 | 0.18% |
| Total | 12041 | 545 |
// 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/blk-integrity.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_limits() */ #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 DEFINE_MUTEX(scsi_sense_cache_mutex); static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd); int scsi_init_sense_cache(struct Scsi_Host *shost) { int ret = 0; mutex_lock(&scsi_sense_cache_mutex); if (!scsi_sense_cache) { 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; } mutex_unlock(&scsi_sense_cache_mutex); return ret; } 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, unsigned long msecs) { struct request *rq = scsi_cmd_to_rq(cmd); if (rq->rq_flags & RQF_DONTPREP) { rq->rq_flags &= ~RQF_DONTPREP; scsi_mq_uninit_cmd(cmd); } else { WARN_ON_ONCE(true); } blk_mq_requeue_request(rq, false); if (!scsi_host_in_recovery(cmd->device->host)) blk_mq_delay_kick_requeue_list(rq->q, msecs); } /** * __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_mq_destroy_queue() finishes. */ cmd->result = 0; blk_mq_requeue_request(scsi_cmd_to_rq(cmd), !scsi_host_in_recovery(cmd->device->host)); } /** * 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); } void scsi_failures_reset_retries(struct scsi_failures *failures) { struct scsi_failure *failure; failures->total_retries = 0; for (failure = failures->failure_definitions; failure->result; failure++) failure->retries = 0; } EXPORT_SYMBOL_GPL(scsi_failures_reset_retries); /** * scsi_check_passthrough - Determine if passthrough scsi_cmnd needs a retry. * @scmd: scsi_cmnd to check. * @failures: scsi_failures struct that lists failures to check for. * * Returns -EAGAIN if the caller should retry else 0. */ static int scsi_check_passthrough(struct scsi_cmnd *scmd, struct scsi_failures *failures) { struct scsi_failure *failure; struct scsi_sense_hdr sshdr; enum sam_status status; if (!failures) return 0; for (failure = failures->failure_definitions; failure->result; failure++) { if (failure->result == SCMD_FAILURE_RESULT_ANY) goto maybe_retry; if (host_byte(scmd->result) && host_byte(scmd->result) == host_byte(failure->result)) goto maybe_retry; status = status_byte(scmd->result); if (!status) continue; if (failure->result == SCMD_FAILURE_STAT_ANY && !scsi_status_is_good(scmd->result)) goto maybe_retry; if (status != status_byte(failure->result)) continue; if (status_byte(failure->result) != SAM_STAT_CHECK_CONDITION || failure->sense == SCMD_FAILURE_SENSE_ANY) goto maybe_retry; if (!scsi_command_normalize_sense(scmd, &sshdr)) return 0; if (failure->sense != sshdr.sense_key) continue; if (failure->asc == SCMD_FAILURE_ASC_ANY) goto maybe_retry; if (failure->asc != sshdr.asc) continue; if (failure->ascq == SCMD_FAILURE_ASCQ_ANY || failure->ascq == sshdr.ascq) goto maybe_retry; } return 0; maybe_retry: if (failure->allowed) { if (failure->allowed == SCMD_FAILURE_NO_LIMIT || ++failure->retries <= failure->allowed) return -EAGAIN; } else { if (failures->total_allowed == SCMD_FAILURE_NO_LIMIT || ++failures->total_retries <= failures->total_allowed) return -EAGAIN; } return 0; } /** * scsi_execute_cmd - insert request and wait for the result * @sdev: scsi_device * @cmd: scsi command * @opf: block layer request cmd_flags * @buffer: data buffer * @bufflen: len of buffer * @timeout: request timeout in HZ * @ml_retries: number of times SCSI midlayer will retry request * @args: Optional args. See struct definition for field descriptions * * Returns the scsi_cmnd result field if a command was executed, or a negative * Linux error code if we didn't get that far. */ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd, blk_opf_t opf, void *buffer, unsigned int bufflen, int timeout, int ml_retries, const struct scsi_exec_args *args) { static const struct scsi_exec_args default_args; struct request *req; struct scsi_cmnd *scmd; int ret; if (!args) args = &default_args; else if (WARN_ON_ONCE(args->sense && args->sense_len != SCSI_SENSE_BUFFERSIZE)) return -EINVAL; retry: req = scsi_alloc_request(sdev->request_queue, opf, args->req_flags); if (IS_ERR(req)) return PTR_ERR(req); if (bufflen) { ret = blk_rq_map_kern(sdev->request_queue, req, buffer, bufflen, GFP_NOIO); if (ret) goto out; } scmd = blk_mq_rq_to_pdu(req); scmd->cmd_len = COMMAND_SIZE(cmd[0]); memcpy(scmd->cmnd, cmd, scmd->cmd_len); scmd->allowed = ml_retries; scmd->flags |= args->scmd_flags; req->timeout = timeout; req->rq_flags |= RQF_QUIET; /* * head injection *required* here otherwise quiesce won't work */ blk_execute_rq(req, true); if (scsi_check_passthrough(scmd, args->failures) == -EAGAIN) { blk_mq_free_request(req); goto retry; } /* * Some devices (USB mass-storage in particular) may transfer * garbage data together with a residue indicating that the data * is invalid. Prevent the garbage from being misinterpreted * and prevent security leaks by zeroing out the excess data. */ if (unlikely(scmd->resid_len > 0 && scmd->resid_len <= bufflen)) memset(buffer + bufflen - scmd->resid_len, 0, scmd->resid_len); if (args->resid) *args->resid = scmd->resid_len; if (args->sense) memcpy(args->sense, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE); if (args->sshdr) scsi_normalize_sense(scmd->sense_buffer, scmd->sense_len, args->sshdr); ret = scmd->result; out: blk_mq_free_request(req); return ret; } EXPORT_SYMBOL(scsi_execute_cmd); /* * 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))) { unsigned int busy = scsi_host_busy(shost); spin_lock_irqsave(shost->host_lock, flags); if (shost->host_failed || shost->host_eh_scheduled) scsi_eh_wakeup(shost, busy); 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); sbitmap_put(&sdev->budget_map, cmd->budget_token); cmd->budget_token = -1; } /* * Kick the queue of SCSI device @sdev if @sdev != current_sdev. Called with * interrupts disabled. */ static void scsi_kick_sdev_queue(struct scsi_device *sdev, void *data) { struct scsi_device *current_sdev = data; if (sdev != current_sdev) blk_mq_run_hw_queues(sdev->request_queue, true); } /* * 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_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. */ blk_mq_run_hw_queues(current_sdev->request_queue, shost->queuecommand_may_block); spin_lock_irqsave(shost->host_lock, flags); if (!starget->starget_sdev_user) __starget_for_each_device(starget, current_sdev, scsi_kick_sdev_queue); spin_unlock_irqrestore(shost->host_lock, flags); } static inline bool scsi_device_is_busy(struct scsi_device *sdev) { if (scsi_device_busy(sdev) >= 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_mq_destroy_queue() before the queue is run from this * function then blk_run_queue() will return immediately since * blk_mq_destroy_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); blk_mq_run_hw_queues(slq, false); 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); /* Note: blk_mq_kick_requeue_list() runs the queue asynchronously. */ blk_mq_kick_requeue_list(q); } 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(scsi_cmd_to_rq(cmd))) { 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_host_in_recovery(sdev->host)) return; 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 (q->limits.features & BLK_FEAT_ADD_RANDOM) add_disk_randomness(req->q->disk); WARN_ON_ONCE(!blk_rq_is_passthrough(req) && !(cmd->flags & SCMD_INITIALIZED)); cmd->flags = 0; /* * 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 * @result: scsi error code * * Translate a SCSI result code into a blk_status_t value. */ static blk_status_t scsi_result_to_blk_status(int result) { /* * Check the scsi-ml byte first in case we converted a host or status * byte. */ switch (scsi_ml_byte(result)) { case SCSIML_STAT_OK: break; case SCSIML_STAT_RESV_CONFLICT: return BLK_STS_RESV_CONFLICT; case SCSIML_STAT_NOSPC: return BLK_STS_NOSPC; case SCSIML_STAT_MED_ERROR: return BLK_STS_MEDIUM; case SCSIML_STAT_TGT_FAILURE: return BLK_STS_TARGET; case SCSIML_STAT_DL_TIMEOUT: return BLK_STS_DURATION_LIMIT; } switch (host_byte(result)) { case DID_OK: if (scsi_status_is_good(result)) return BLK_STS_OK; return BLK_STS_IOERR; case DID_TRANSPORT_FAILFAST: case DID_TRANSPORT_MARGINAL: return BLK_STS_TRANSPORT; default: return BLK_STS_IOERR; } } /** * scsi_rq_err_bytes - determine number of bytes till the next failure boundary * @rq: request to examine * * Description: * A request could be merge of IOs which require different failure * handling. This function determines the number of bytes which * can be failed from the beginning of the request without * crossing into area which need to be retried further. * * Return: * The number of bytes to fail. */ static unsigned int scsi_rq_err_bytes(const struct request *rq) { blk_opf_t ff = rq->cmd_flags & REQ_FAILFAST_MASK; unsigned int bytes = 0; struct bio *bio; if (!(rq->rq_flags & RQF_MIXED_MERGE)) return blk_rq_bytes(rq); /* * Currently the only 'mixing' which can happen is between * different fastfail types. We can safely fail portions * which have all the failfast bits that the first one has - * the ones which are at least as eager to fail as the first * one. */ for (bio = rq->bio; bio; bio = bio->bi_next) { if ((bio->bi_opf & ff) != ff) break; bytes += bio->bi_iter.bi_size; } /* this could lead to infinite loop */ BUG_ON(blk_rq_bytes(rq) && !bytes); return bytes; } static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd) { struct request *req = scsi_cmd_to_rq(cmd); 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; } /* * When ALUA transition state is returned, reprep the cmd to * use the ALUA handler's transition timeout. Delay the reprep * 1 sec to avoid aggressive retries of the target in that * state. */ #define ALUA_TRANSITION_REPREP_DELAY 1000 /* Helper for scsi_io_completion() when special action required. */ static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result) { struct request *req = scsi_cmd_to_rq(cmd); int level = 0; enum {ACTION_FAIL, ACTION_REPREP, ACTION_DELAYED_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(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 */ case 0x25: /* depopulation restore in progress */ action = ACTION_DELAYED_RETRY; break; case 0x0a: /* ALUA state transition */ action = ACTION_DELAYED_REPREP; 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; case COMPLETED: fallthrough; 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 (sense_valid) scsi_print_sense(cmd); scsi_print_command(cmd); } } if (!scsi_end_request(req, blk_stat, scsi_rq_err_bytes(req))) return; fallthrough; case ACTION_REPREP: scsi_mq_requeue_cmd(cmd, 0); break; case ACTION_DELAYED_REPREP: scsi_mq_requeue_cmd(cmd, ALUA_TRANSITION_REPREP_DELAY); 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 = scsi_cmd_to_rq(cmd); 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 */ cmd->sense_len = min(8 + cmd->sense_buffer[7], SCSI_SENSE_BUFFERSIZE); } if (sense_current) *blk_statp = scsi_result_to_blk_status(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(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 ((result & 0xff) && 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_mq_requeue_cmd(). 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 *req = scsi_cmd_to_rq(cmd); 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); /* * 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 * request just queue the command up again. */ if (likely(result == 0)) scsi_mq_requeue_cmd(cmd, 0); 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 and initialize data and integrity scatterlists * @cmd: SCSI command data structure to initialize. * * Initializes @cmd->sdb and also @cmd->prot_sdb if data integrity is enabled * for @cmd. * * 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 = scsi_cmd_to_rq(cmd); 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->limits.dma_pad_mask) { unsigned int pad_len = (rq->q->limits.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. */ static void scsi_initialize_rq(struct request *rq) { struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); cmd->cmd_len = MAX_COMMAND_SIZE; cmd->sense_len = 0; init_rcu_head(&cmd->rcu); cmd->jiffies_at_alloc = jiffies; cmd->retries = 0; } struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf, blk_mq_req_flags_t flags) { struct request *rq; rq = blk_mq_alloc_request(q, opf, flags); if (!IS_ERR(rq)) scsi_initialize_rq(rq); return rq; } EXPORT_SYMBOL_GPL(scsi_alloc_request); /* * 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) { struct request *rq = scsi_cmd_to_rq(cmd); if (!blk_rq_is_passthrough(rq) && !(cmd->flags & SCMD_INITIALIZED)) { cmd->flags |= SCMD_INITIALIZED; scsi_initialize_rq(rq); } cmd->device = dev; INIT_LIST_HEAD(&cmd->eh_entry); INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); } 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->transfersize = blk_rq_bytes(req); 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_OFFLINE; return BLK_STS_OK; } } /* * scsi_dev_queue_ready: if we can send requests to sdev, assign one token * and return the token else return -1. */ static inline int scsi_dev_queue_ready(struct request_queue *q, struct scsi_device *sdev) { int token; token = sbitmap_get(&sdev->budget_map); if (token < 0) return -1; if (!atomic_read(&sdev->device_blocked)) return token; /* * Only unblock if no other commands are pending and * if device_blocked has decreased to zero */ if (scsi_device_busy(sdev) > 1 || atomic_dec_return(&sdev->device_blocked) > 0) { sbitmap_put(&sdev->budget_map, token); return -1; } SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, "unblocking device at zero depth\n")); return token; } /* * 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 (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; } /* * Block layer request completion callback. May be called from interrupt * context. */ static void scsi_complete(struct request *rq) { struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); enum scsi_disposition 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_cmd - 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")); atomic_dec(&cmd->device->iorequest_cnt); 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) { atomic_dec(&cmd->device->iorequest_cnt); 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: 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; bool in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); struct scatterlist *sg; scsi_init_command(sdev, cmd); cmd->eh_eflags = 0; cmd->prot_type = 0; cmd->prot_flags = 0; cmd->submitter = 0; memset(&cmd->sdb, 0, sizeof(cmd->sdb)); cmd->underflow = 0; cmd->transfersize = 0; cmd->host_scribble = NULL; cmd->result = 0; cmd->extra_len = 0; cmd->state = 0; if (in_flight) __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); /* * Only clear the driver-private command data if the LLD does not supply * a function to initialize that data. */ if (!shost->hostt->init_cmd_priv) memset(cmd + 1, 0, shost->hostt->cmd_size); 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_passthrough(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; } /* Usually overridden by the ULP */ cmd->allowed = 0; memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); return scsi_cmd_to_driver(cmd)->init_command(cmd); } static void scsi_done_internal(struct scsi_cmnd *cmd, bool complete_directly) { struct request *req = scsi_cmd_to_rq(cmd); switch (cmd->submitter) { case SUBMITTED_BY_BLOCK_LAYER: break; case SUBMITTED_BY_SCSI_ERROR_HANDLER: return scsi_eh_done(cmd); case SUBMITTED_BY_SCSI_RESET_IOCTL: return; } if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q))) return; if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) return; trace_scsi_dispatch_cmd_done(cmd); if (complete_directly) blk_mq_complete_request_direct(req, scsi_complete); else blk_mq_complete_request(req); } void scsi_done(struct scsi_cmnd *cmd) { scsi_done_internal(cmd, false); } EXPORT_SYMBOL(scsi_done); void scsi_done_direct(struct scsi_cmnd *cmd) { scsi_done_internal(cmd, true); } EXPORT_SYMBOL(scsi_done_direct); static void scsi_mq_put_budget(struct request_queue *q, int budget_token) { struct scsi_device *sdev = q->queuedata; sbitmap_put(&sdev->budget_map, budget_token); } /* * 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 int scsi_mq_get_budget(struct request_queue *q) { struct scsi_device *sdev = q->queuedata; int token = scsi_dev_queue_ready(q, sdev); if (token >= 0) return token; 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(scsi_device_busy(sdev) == 0 && !scsi_device_blocked(sdev))) blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY); return -1; } static void scsi_mq_set_rq_budget_token(struct request *req, int token) { struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); cmd->budget_token = token; } static int scsi_mq_get_rq_budget_token(struct request *req) { struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); return cmd->budget_token; } 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; WARN_ON_ONCE(cmd->budget_token < 0); /* * 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 (unlikely(scsi_host_in_recovery(shost))) { if (cmd->flags & SCMD_FAIL_IF_RECOVERING) ret = BLK_STS_OFFLINE; goto out_dec_target_busy; } 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->submitter = SUBMITTED_BY_BLOCK_LAYER; 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, cmd->budget_token); cmd->budget_token = -1; switch (ret) { case BLK_STS_OK: break; case BLK_STS_RESOURCE: if (scsi_device_blocked(sdev)) ret = BLK_STS_DEV_RESOURCE; break; case BLK_STS_AGAIN: cmd->result = DID_BUS_BUSY << 16; if (req->rq_flags & RQF_DONTPREP) scsi_mq_uninit_cmd(cmd); break; default: if (unlikely(!scsi_device_online(sdev))) cmd->result = DID_NO_CONNECT << 16; else cmd->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 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; struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); struct scatterlist *sg; int ret = 0; cmd->sense_buffer = kmem_cache_alloc_node(scsi_sense_cache, GFP_KERNEL, numa_node); if (!cmd->sense_buffer) return -ENOMEM; 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) kmem_cache_free(scsi_sense_cache, 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); kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); } static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) { struct Scsi_Host *shost = hctx->driver_data; if (shost->hostt->mq_poll) return shost->hostt->mq_poll(shost, hctx->queue_num); return 0; } static int scsi_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, unsigned int hctx_idx) { struct Scsi_Host *shost = data; hctx->driver_data = shost; return 0; } static void 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); blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); } void scsi_init_limits(struct Scsi_Host *shost, struct queue_limits *lim) { struct device *dev = shost->dma_dev; memset(lim, 0, sizeof(*lim)); lim->max_segments = 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); lim->max_integrity_segments = shost->sg_prot_tablesize; } lim->max_hw_sectors = shost->max_sectors; lim->seg_boundary_mask = shost->dma_boundary; lim->max_segment_size = shost->max_segment_size; lim->virt_boundary_mask = shost->virt_boundary_mask; lim->dma_alignment = max_t(unsigned int, shost->dma_alignment, dma_get_cache_alignment() - 1); if (shost->no_highmem) lim->features |= BLK_FEAT_BOUNCE_HIGH; dma_set_seg_boundary(dev, shost->dma_boundary); dma_set_max_seg_size(dev, shost->max_segment_size); } EXPORT_SYMBOL_GPL(scsi_init_limits); 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_complete, .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, .cleanup_rq = scsi_cleanup_rq, .busy = scsi_mq_lld_busy, .map_queues = scsi_map_queues, .init_hctx = scsi_init_hctx, .poll = scsi_mq_poll, .set_rq_budget_token = scsi_mq_set_rq_budget_token, .get_rq_budget_token = scsi_mq_get_rq_budget_token, }; static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx) { struct Scsi_Host *shost = hctx->driver_data; 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_complete, .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, .cleanup_rq = scsi_cleanup_rq, .busy = scsi_mq_lld_busy, .map_queues = scsi_map_queues, .init_hctx = scsi_init_hctx, .poll = scsi_mq_poll, .set_rq_budget_token = scsi_mq_set_rq_budget_token, .get_rq_budget_token = scsi_mq_get_rq_budget_token, }; 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->nr_maps = shost->nr_maps ? : 1; tag_set->queue_depth = shost->can_queue; tag_set->cmd_size = cmd_size; tag_set->numa_node = dev_to_node(shost->dma_dev); tag_set->flags = BLK_MQ_F_SHOULD_MERGE; tag_set->flags |= BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); if (shost->queuecommand_may_block) tag_set->flags |= BLK_MQ_F_BLOCKING; 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_free_tags(struct kref *kref) { struct Scsi_Host *shost = container_of(kref, typeof(*shost), tagset_refcnt); blk_mq_free_tag_set(&shost->tag_set); complete(&shost->tagset_freed); } /** * 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; } /* * pktcdvd should have been integrated into the SCSI layers, but for historical * reasons like the old IDE driver it isn't. This export allows it to safely * probe if a given device is a SCSI one and only attach to that. */ #ifdef CONFIG_CDROM_PKTCDVD_MODULE EXPORT_SYMBOL_GPL(scsi_device_from_queue); #endif /** * 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); } /** * 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) * @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, 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; const struct scsi_exec_args exec_args = { .sshdr = sshdr, }; int ret; memset(cmd, 0, sizeof(cmd)); cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); /* * Use MODE SELECT(10) if the device asked for it or if the mode page * and the mode select header cannot fit within the maximumm 255 bytes * of the MODE SELECT(6) command. */ if (sdev->use_10_for_ms || len + 4 > 255 || data->block_descriptor_length > 255) { if (len > 65535 - 8) 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; put_unaligned_be16(data->block_descriptor_length, &real_buffer[6]); cmd[0] = MODE_SELECT_10; put_unaligned_be16(len, &cmd[7]); } else { if (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_cmd(sdev, cmd, REQ_OP_DRV_OUT, real_buffer, len, timeout, retries, &exec_args); 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 to prevent mode sense from returning block descriptors * @modepage: mode page being requested * @subpage: sub-page of the 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, int subpage, 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; struct scsi_sense_hdr my_sshdr; struct scsi_failure failure_defs[] = { { .sense = UNIT_ATTENTION, .asc = SCMD_FAILURE_ASC_ANY, .ascq = SCMD_FAILURE_ASCQ_ANY, .allowed = retries, .result = SAM_STAT_CHECK_CONDITION, }, {} }; struct scsi_failures failures = { .failure_definitions = failure_defs, }; const struct scsi_exec_args exec_args = { /* caller might not be interested in sense, but we need it */ .sshdr = sshdr ? : &my_sshdr, .failures = &failures, }; 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; cmd[3] = subpage; sshdr = exec_args.sshdr; retry: use_10_for_ms = sdev->use_10_for_ms || len > 255; if (use_10_for_ms) { if (len < 8 || len > 65535) return -EINVAL; cmd[0] = MODE_SENSE_10; put_unaligned_be16(len, &cmd[7]); header_length = 8; } else { if (len < 4) return -EINVAL; cmd[0] = MODE_SENSE; cmd[4] = len; header_length = 4; } memset(buffer, 0, len); result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, len, timeout, retries, &exec_args); 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 (!scsi_status_is_good(result)) { if (scsi_sense_valid(sshdr)) { if ((sshdr->sense_key == ILLEGAL_REQUEST) && (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { /* * Invalid command operation code: retry using * MODE SENSE(6) if this was a MODE SENSE(10) * request, except if the request mode page is * too large for MODE SENSE single byte * allocation length field. */ if (use_10_for_ms) { if (len > 255) return -EIO; sdev->use_10_for_ms = 0; goto retry; } } } return -EIO; } 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 = get_unaligned_be16(&buffer[0]) + 2; data->medium_type = buffer[2]; data->device_specific = buffer[3]; data->longlba = buffer[4] & 0x01; data->block_descriptor_length = get_unaligned_be16(&buffer[6]); } 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; return 0; } 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, }; const struct scsi_exec_args exec_args = { .sshdr = sshdr, }; int result; /* try to eat the UNIT_ATTENTION if there are enough retries */ do { result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, NULL, 0, timeout, 1, &exec_args); if (sdev->removable && result > 0 && scsi_sense_valid(sshdr) && sshdr->sense_key == UNIT_ATTENTION) sdev->changed = 1; } while (result > 0 && 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); /** * scsi_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); 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); } /** * scsi_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); static int __scsi_internal_device_block_nowait(struct scsi_device *sdev) { if (scsi_device_set_state(sdev, SDEV_BLOCK)) return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); return 0; } void scsi_start_queue(struct scsi_device *sdev) { if (cmpxchg(&sdev->queue_stopped, 1, 0)) blk_mq_unquiesce_queue(sdev->request_queue); } static void scsi_stop_queue(struct scsi_device *sdev) { /* * The atomic variable of ->queue_stopped covers that * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue. * * The caller needs to wait until quiesce is done. */ if (!cmpxchg(&sdev->queue_stopped, 0, 1)) blk_mq_quiesce_queue_nowait(sdev->request_queue); } /** * 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) { int ret = __scsi_internal_device_block_nowait(sdev); /* * The device has transitioned to SDEV_BLOCK. Stop the * block layer from calling the midlayer with this device's * request queue. */ if (!ret) scsi_stop_queue(sdev); return ret; } EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); /** * scsi_device_block - try to transition to the SDEV_BLOCK state * @sdev: device to block * @data: dummy argument, ignored * * Pause SCSI command processing on the specified device. Callers must wait * until all ongoing scsi_queue_rq() calls have finished after this function * returns. * * 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 void scsi_device_block(struct scsi_device *sdev, void *data) { int err; enum scsi_device_state state; mutex_lock(&sdev->state_mutex); err = __scsi_internal_device_block_nowait(sdev); state = sdev->sdev_state; if (err == 0) /* * scsi_stop_queue() must be called with the state_mutex * held. Otherwise a simultaneous scsi_start_queue() call * might unquiesce the queue before we quiesce it. */ scsi_stop_queue(sdev); mutex_unlock(&sdev->state_mutex); WARN_ONCE(err, "%s: failed to block %s in state %d\n", __func__, dev_name(&sdev->sdev_gendev), state); } /** * 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 int target_block(struct device *dev, void *data) { if (scsi_is_target_device(dev)) starget_for_each_device(to_scsi_target(dev), NULL, scsi_device_block); return 0; } /** * scsi_block_targets - transition all SCSI child devices to SDEV_BLOCK state * @dev: a parent device of one or more scsi_target devices * @shost: the Scsi_Host to which this device belongs * * Iterate over all children of @dev, which should be scsi_target devices, * and switch all subordinate scsi devices to SDEV_BLOCK state. Wait for * ongoing scsi_queue_rq() calls to finish. May sleep. * * Note: * @dev must not itself be a scsi_target device. */ void scsi_block_targets(struct Scsi_Host *shost, struct device *dev) { WARN_ON_ONCE(scsi_is_target_device(dev)); device_for_each_child(dev, NULL, target_block); blk_mq_wait_quiesce_done(&shost->tag_set); } EXPORT_SYMBOL_GPL(scsi_block_targets); 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); /** * scsi_host_block - Try to transition all logical units to the SDEV_BLOCK state * @shost: device to block * * Pause SCSI command processing for all logical units associated with the SCSI * host and wait until pending scsi_queue_rq() calls have finished. * * Returns zero if successful or a negative error code upon failure. */ int scsi_host_block(struct Scsi_Host *shost) { struct scsi_device *sdev; int ret; /* * 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); return ret; } } /* Wait for ongoing scsi_queue_rq() calls to finish. */ blk_mq_wait_quiesce_done(&shost->tag_set); return 0; } 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); for (d = vpd_pg83->data + 4; d < vpd_pg83->data + vpd_pg83->len; d += d[3] + 4) { u8 prio = designator_prio(d); if (prio == 0 || cur_id_prio > prio) continue; 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; } } 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); /** * scsi_build_sense - build sense data for a command * @scmd: scsi command for which the sense should be formatted * @desc: Sense format (non-zero == descriptor format, * 0 == fixed format) * @key: Sense key * @asc: Additional sense code * @ascq: Additional sense code qualifier * **/ void scsi_build_sense(struct scsi_cmnd *scmd, int desc, u8 key, u8 asc, u8 ascq) { scsi_build_sense_buffer(desc, scmd->sense_buffer, key, asc, ascq); scmd->result = SAM_STAT_CHECK_CONDITION; } EXPORT_SYMBOL_GPL(scsi_build_sense); #ifdef CONFIG_SCSI_LIB_KUNIT_TEST #include "scsi_lib_test.c" #endif
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