3377 lines
86 KiB
C
3377 lines
86 KiB
C
/*
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* Copyright (C) 1999 Eric Youngdale
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* Copyright (C) 2014 Christoph Hellwig
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*
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* SCSI queueing library.
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* Initial versions: Eric Youngdale (eric@andante.org).
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* Based upon conversations with large numbers
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* of people at Linux Expo.
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*/
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#include <linux/bio.h>
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#include <linux/bitops.h>
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#include <linux/blkdev.h>
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#include <linux/completion.h>
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/init.h>
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#include <linux/pci.h>
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#include <linux/delay.h>
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#include <linux/hardirq.h>
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#include <linux/scatterlist.h>
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#include <linux/blk-mq.h>
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#include <linux/ratelimit.h>
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#include <asm/unaligned.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_dbg.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_driver.h>
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#include <scsi/scsi_eh.h>
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#include <scsi/scsi_host.h>
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#include <scsi/scsi_dh.h>
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#include <trace/events/scsi.h>
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#include "scsi_priv.h"
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#include "scsi_logging.h"
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static struct kmem_cache *scsi_sdb_cache;
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static struct kmem_cache *scsi_sense_cache;
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static struct kmem_cache *scsi_sense_isadma_cache;
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static DEFINE_MUTEX(scsi_sense_cache_mutex);
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static inline struct kmem_cache *
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scsi_select_sense_cache(struct Scsi_Host *shost)
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{
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return shost->unchecked_isa_dma ?
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scsi_sense_isadma_cache : scsi_sense_cache;
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}
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static void scsi_free_sense_buffer(struct Scsi_Host *shost,
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unsigned char *sense_buffer)
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{
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kmem_cache_free(scsi_select_sense_cache(shost), sense_buffer);
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}
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static unsigned char *scsi_alloc_sense_buffer(struct Scsi_Host *shost,
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gfp_t gfp_mask, int numa_node)
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{
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return kmem_cache_alloc_node(scsi_select_sense_cache(shost), gfp_mask,
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numa_node);
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}
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int scsi_init_sense_cache(struct Scsi_Host *shost)
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{
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struct kmem_cache *cache;
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int ret = 0;
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cache = scsi_select_sense_cache(shost);
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if (cache)
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return 0;
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mutex_lock(&scsi_sense_cache_mutex);
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if (shost->unchecked_isa_dma) {
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scsi_sense_isadma_cache =
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kmem_cache_create("scsi_sense_cache(DMA)",
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SCSI_SENSE_BUFFERSIZE, 0,
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SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL);
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if (!scsi_sense_isadma_cache)
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ret = -ENOMEM;
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} else {
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scsi_sense_cache =
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kmem_cache_create("scsi_sense_cache",
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SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN, NULL);
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if (!scsi_sense_cache)
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ret = -ENOMEM;
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}
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mutex_unlock(&scsi_sense_cache_mutex);
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return ret;
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}
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/*
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* When to reinvoke queueing after a resource shortage. It's 3 msecs to
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* not change behaviour from the previous unplug mechanism, experimentation
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* may prove this needs changing.
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*/
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#define SCSI_QUEUE_DELAY 3
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static void
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scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
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{
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struct Scsi_Host *host = cmd->device->host;
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struct scsi_device *device = cmd->device;
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struct scsi_target *starget = scsi_target(device);
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/*
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* Set the appropriate busy bit for the device/host.
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*
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* If the host/device isn't busy, assume that something actually
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* completed, and that we should be able to queue a command now.
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*
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* Note that the prior mid-layer assumption that any host could
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* always queue at least one command is now broken. The mid-layer
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* will implement a user specifiable stall (see
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* scsi_host.max_host_blocked and scsi_device.max_device_blocked)
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* if a command is requeued with no other commands outstanding
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* either for the device or for the host.
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*/
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switch (reason) {
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case SCSI_MLQUEUE_HOST_BUSY:
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atomic_set(&host->host_blocked, host->max_host_blocked);
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break;
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case SCSI_MLQUEUE_DEVICE_BUSY:
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case SCSI_MLQUEUE_EH_RETRY:
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atomic_set(&device->device_blocked,
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device->max_device_blocked);
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break;
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case SCSI_MLQUEUE_TARGET_BUSY:
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atomic_set(&starget->target_blocked,
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starget->max_target_blocked);
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break;
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}
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}
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static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
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{
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struct scsi_device *sdev = cmd->device;
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blk_mq_requeue_request(cmd->request, true);
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put_device(&sdev->sdev_gendev);
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}
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/**
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* __scsi_queue_insert - private queue insertion
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* @cmd: The SCSI command being requeued
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* @reason: The reason for the requeue
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* @unbusy: Whether the queue should be unbusied
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*
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* This is a private queue insertion. The public interface
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* scsi_queue_insert() always assumes the queue should be unbusied
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* because it's always called before the completion. This function is
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* for a requeue after completion, which should only occur in this
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* file.
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*/
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static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
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{
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struct scsi_device *device = cmd->device;
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struct request_queue *q = device->request_queue;
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unsigned long flags;
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SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd,
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"Inserting command %p into mlqueue\n", cmd));
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scsi_set_blocked(cmd, reason);
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/*
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* Decrement the counters, since these commands are no longer
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* active on the host/device.
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*/
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if (unbusy)
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scsi_device_unbusy(device);
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/*
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* Requeue this command. It will go before all other commands
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* that are already in the queue. Schedule requeue work under
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* lock such that the kblockd_schedule_work() call happens
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* before blk_cleanup_queue() finishes.
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*/
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cmd->result = 0;
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if (q->mq_ops) {
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scsi_mq_requeue_cmd(cmd);
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return;
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}
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spin_lock_irqsave(q->queue_lock, flags);
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blk_requeue_request(q, cmd->request);
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kblockd_schedule_work(&device->requeue_work);
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spin_unlock_irqrestore(q->queue_lock, flags);
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}
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/*
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* Function: scsi_queue_insert()
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*
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* Purpose: Insert a command in the midlevel queue.
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*
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* Arguments: cmd - command that we are adding to queue.
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* reason - why we are inserting command to queue.
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*
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* Lock status: Assumed that lock is not held upon entry.
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*
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* Returns: Nothing.
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*
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* Notes: We do this for one of two cases. Either the host is busy
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* and it cannot accept any more commands for the time being,
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* or the device returned QUEUE_FULL and can accept no more
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* commands.
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* Notes: This could be called either from an interrupt context or a
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* normal process context.
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*/
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void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
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{
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__scsi_queue_insert(cmd, reason, 1);
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}
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static int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
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int data_direction, void *buffer, unsigned bufflen,
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unsigned char *sense, int timeout, int retries, u64 flags,
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req_flags_t rq_flags, int *resid)
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{
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struct request *req;
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struct scsi_request *rq;
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int ret = DRIVER_ERROR << 24;
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req = blk_get_request(sdev->request_queue,
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data_direction == DMA_TO_DEVICE ?
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REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, __GFP_RECLAIM);
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if (IS_ERR(req))
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return ret;
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rq = scsi_req(req);
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scsi_req_init(req);
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if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
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buffer, bufflen, __GFP_RECLAIM))
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goto out;
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rq->cmd_len = COMMAND_SIZE(cmd[0]);
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memcpy(rq->cmd, cmd, rq->cmd_len);
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req->retries = retries;
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req->timeout = timeout;
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req->cmd_flags |= flags;
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req->rq_flags |= rq_flags | RQF_QUIET | RQF_PREEMPT;
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/*
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* head injection *required* here otherwise quiesce won't work
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*/
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blk_execute_rq(req->q, NULL, req, 1);
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/*
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* Some devices (USB mass-storage in particular) may transfer
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* garbage data together with a residue indicating that the data
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* is invalid. Prevent the garbage from being misinterpreted
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* and prevent security leaks by zeroing out the excess data.
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*/
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if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen))
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memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len);
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if (resid)
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*resid = rq->resid_len;
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if (sense && rq->sense_len)
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memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
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ret = req->errors;
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out:
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blk_put_request(req);
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return ret;
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}
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/**
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* scsi_execute - insert request and wait for the result
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* @sdev: scsi device
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* @cmd: scsi command
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* @data_direction: data direction
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* @buffer: data buffer
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* @bufflen: len of buffer
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* @sense: optional sense buffer
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* @timeout: request timeout in seconds
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* @retries: number of times to retry request
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* @flags: or into request flags;
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* @resid: optional residual length
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*
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* returns the req->errors value which is the scsi_cmnd result
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* field.
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*/
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int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
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int data_direction, void *buffer, unsigned bufflen,
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unsigned char *sense, int timeout, int retries, u64 flags,
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int *resid)
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{
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return __scsi_execute(sdev, cmd, data_direction, buffer, bufflen, sense,
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timeout, retries, flags, 0, resid);
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}
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EXPORT_SYMBOL(scsi_execute);
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int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd,
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int data_direction, void *buffer, unsigned bufflen,
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struct scsi_sense_hdr *sshdr, int timeout, int retries,
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int *resid, u64 flags, req_flags_t rq_flags)
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{
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char *sense = NULL;
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int result;
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if (sshdr) {
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sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
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if (!sense)
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return DRIVER_ERROR << 24;
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}
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result = __scsi_execute(sdev, cmd, data_direction, buffer, bufflen,
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sense, timeout, retries, flags, rq_flags, resid);
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if (sshdr)
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scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr);
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kfree(sense);
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return result;
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}
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EXPORT_SYMBOL(scsi_execute_req_flags);
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/*
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* Function: scsi_init_cmd_errh()
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*
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* Purpose: Initialize cmd fields related to error handling.
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*
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* Arguments: cmd - command that is ready to be queued.
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*
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* Notes: This function has the job of initializing a number of
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* fields related to error handling. Typically this will
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* be called once for each command, as required.
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*/
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static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
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{
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cmd->serial_number = 0;
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scsi_set_resid(cmd, 0);
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memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
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if (cmd->cmd_len == 0)
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cmd->cmd_len = scsi_command_size(cmd->cmnd);
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}
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void scsi_device_unbusy(struct scsi_device *sdev)
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{
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struct Scsi_Host *shost = sdev->host;
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struct scsi_target *starget = scsi_target(sdev);
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unsigned long flags;
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atomic_dec(&shost->host_busy);
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if (starget->can_queue > 0)
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atomic_dec(&starget->target_busy);
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if (unlikely(scsi_host_in_recovery(shost) &&
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(shost->host_failed || shost->host_eh_scheduled))) {
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spin_lock_irqsave(shost->host_lock, flags);
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scsi_eh_wakeup(shost);
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spin_unlock_irqrestore(shost->host_lock, flags);
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}
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atomic_dec(&sdev->device_busy);
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}
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static void scsi_kick_queue(struct request_queue *q)
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{
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if (q->mq_ops)
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blk_mq_start_hw_queues(q);
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else
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blk_run_queue(q);
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}
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/*
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* Called for single_lun devices on IO completion. Clear starget_sdev_user,
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* and call blk_run_queue for all the scsi_devices on the target -
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* including current_sdev first.
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*
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* Called with *no* scsi locks held.
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*/
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static void scsi_single_lun_run(struct scsi_device *current_sdev)
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{
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struct Scsi_Host *shost = current_sdev->host;
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struct scsi_device *sdev, *tmp;
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struct scsi_target *starget = scsi_target(current_sdev);
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unsigned long flags;
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spin_lock_irqsave(shost->host_lock, flags);
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starget->starget_sdev_user = NULL;
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spin_unlock_irqrestore(shost->host_lock, flags);
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/*
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* Call blk_run_queue for all LUNs on the target, starting with
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* current_sdev. We race with others (to set starget_sdev_user),
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* but in most cases, we will be first. Ideally, each LU on the
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* target would get some limited time or requests on the target.
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*/
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scsi_kick_queue(current_sdev->request_queue);
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spin_lock_irqsave(shost->host_lock, flags);
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if (starget->starget_sdev_user)
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goto out;
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list_for_each_entry_safe(sdev, tmp, &starget->devices,
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same_target_siblings) {
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if (sdev == current_sdev)
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continue;
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if (scsi_device_get(sdev))
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continue;
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spin_unlock_irqrestore(shost->host_lock, flags);
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scsi_kick_queue(sdev->request_queue);
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spin_lock_irqsave(shost->host_lock, flags);
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scsi_device_put(sdev);
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}
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out:
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spin_unlock_irqrestore(shost->host_lock, flags);
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}
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static inline bool scsi_device_is_busy(struct scsi_device *sdev)
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{
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if (atomic_read(&sdev->device_busy) >= sdev->queue_depth)
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return true;
|
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if (atomic_read(&sdev->device_blocked) > 0)
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return true;
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return false;
|
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}
|
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|
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static inline bool scsi_target_is_busy(struct scsi_target *starget)
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{
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if (starget->can_queue > 0) {
|
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if (atomic_read(&starget->target_busy) >= starget->can_queue)
|
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return true;
|
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if (atomic_read(&starget->target_blocked) > 0)
|
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return true;
|
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}
|
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return false;
|
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}
|
|
|
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static inline bool scsi_host_is_busy(struct Scsi_Host *shost)
|
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{
|
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if (shost->can_queue > 0 &&
|
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atomic_read(&shost->host_busy) >= shost->can_queue)
|
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return true;
|
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if (atomic_read(&shost->host_blocked) > 0)
|
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return true;
|
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if (shost->host_self_blocked)
|
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return true;
|
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return false;
|
|
}
|
|
|
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static void scsi_starved_list_run(struct Scsi_Host *shost)
|
|
{
|
|
LIST_HEAD(starved_list);
|
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struct scsi_device *sdev;
|
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unsigned long flags;
|
|
|
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spin_lock_irqsave(shost->host_lock, flags);
|
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list_splice_init(&shost->starved_list, &starved_list);
|
|
|
|
while (!list_empty(&starved_list)) {
|
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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
|
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* starved_list.
|
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*
|
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* host_lock protects the starved_list and starved_entry.
|
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* scsi_request_fn must get the host_lock before checking
|
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* or modifying starved_list or starved_entry.
|
|
*/
|
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if (scsi_host_is_busy(shost))
|
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break;
|
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|
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sdev = list_entry(starved_list.next,
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struct scsi_device, starved_entry);
|
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list_del_init(&sdev->starved_entry);
|
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if (scsi_target_is_busy(scsi_target(sdev))) {
|
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list_move_tail(&sdev->starved_entry,
|
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&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);
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_run_queue()
|
|
*
|
|
* Purpose: Select a proper request queue to serve next
|
|
*
|
|
* Arguments: q - last request's queue
|
|
*
|
|
* Returns: Nothing
|
|
*
|
|
* Notes: 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);
|
|
|
|
if (q->mq_ops)
|
|
blk_mq_start_stopped_hw_queues(q, false);
|
|
else
|
|
blk_run_queue(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);
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_requeue_command()
|
|
*
|
|
* Purpose: Handle post-processing of completed commands.
|
|
*
|
|
* Arguments: q - queue to operate on
|
|
* cmd - command that may need to be requeued.
|
|
*
|
|
* Returns: Nothing
|
|
*
|
|
* Notes: After command completion, there may be blocks left
|
|
* over which weren't finished by the previous command
|
|
* this can be for a number of reasons - the main one is
|
|
* I/O errors in the middle of the request, in which case
|
|
* we need to request the blocks that come after the bad
|
|
* sector.
|
|
* Notes: Upon return, cmd is a stale pointer.
|
|
*/
|
|
static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
|
|
{
|
|
struct scsi_device *sdev = cmd->device;
|
|
struct request *req = cmd->request;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
blk_unprep_request(req);
|
|
req->special = NULL;
|
|
scsi_put_command(cmd);
|
|
blk_requeue_request(q, req);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
|
|
scsi_run_queue(q);
|
|
|
|
put_device(&sdev->sdev_gendev);
|
|
}
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
|
|
{
|
|
struct scsi_data_buffer *sdb;
|
|
|
|
if (cmd->sdb.table.nents)
|
|
sg_free_table_chained(&cmd->sdb.table, true);
|
|
if (cmd->request->next_rq) {
|
|
sdb = cmd->request->next_rq->special;
|
|
if (sdb)
|
|
sg_free_table_chained(&sdb->table, true);
|
|
}
|
|
if (scsi_prot_sg_count(cmd))
|
|
sg_free_table_chained(&cmd->prot_sdb->table, true);
|
|
}
|
|
|
|
static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
|
|
{
|
|
struct scsi_device *sdev = cmd->device;
|
|
struct Scsi_Host *shost = sdev->host;
|
|
unsigned long flags;
|
|
|
|
scsi_mq_free_sgtables(cmd);
|
|
scsi_uninit_cmd(cmd);
|
|
|
|
if (shost->use_cmd_list) {
|
|
BUG_ON(list_empty(&cmd->list));
|
|
spin_lock_irqsave(&sdev->list_lock, flags);
|
|
list_del_init(&cmd->list);
|
|
spin_unlock_irqrestore(&sdev->list_lock, flags);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_release_buffers()
|
|
*
|
|
* Purpose: Free resources allocate for a scsi_command.
|
|
*
|
|
* Arguments: cmd - command that we are bailing.
|
|
*
|
|
* Lock status: Assumed that no lock is held upon entry.
|
|
*
|
|
* Returns: Nothing
|
|
*
|
|
* Notes: In the event that an upper level driver rejects a
|
|
* command, we must release resources allocated during
|
|
* the __init_io() function. Primarily this would involve
|
|
* the scatter-gather table.
|
|
*/
|
|
static void scsi_release_buffers(struct scsi_cmnd *cmd)
|
|
{
|
|
if (cmd->sdb.table.nents)
|
|
sg_free_table_chained(&cmd->sdb.table, false);
|
|
|
|
memset(&cmd->sdb, 0, sizeof(cmd->sdb));
|
|
|
|
if (scsi_prot_sg_count(cmd))
|
|
sg_free_table_chained(&cmd->prot_sdb->table, false);
|
|
}
|
|
|
|
static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd)
|
|
{
|
|
struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special;
|
|
|
|
sg_free_table_chained(&bidi_sdb->table, false);
|
|
kmem_cache_free(scsi_sdb_cache, bidi_sdb);
|
|
cmd->request->next_rq->special = NULL;
|
|
}
|
|
|
|
static bool scsi_end_request(struct request *req, int error,
|
|
unsigned int bytes, unsigned int bidi_bytes)
|
|
{
|
|
struct scsi_cmnd *cmd = req->special;
|
|
struct scsi_device *sdev = cmd->device;
|
|
struct request_queue *q = sdev->request_queue;
|
|
|
|
if (blk_update_request(req, error, bytes))
|
|
return true;
|
|
|
|
/* Bidi request must be completed as a whole */
|
|
if (unlikely(bidi_bytes) &&
|
|
blk_update_request(req->next_rq, error, bidi_bytes))
|
|
return true;
|
|
|
|
if (blk_queue_add_random(q))
|
|
add_disk_randomness(req->rq_disk);
|
|
|
|
if (req->mq_ctx) {
|
|
/*
|
|
* 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);
|
|
|
|
__blk_mq_end_request(req, error);
|
|
|
|
if (scsi_target(sdev)->single_lun ||
|
|
!list_empty(&sdev->host->starved_list))
|
|
kblockd_schedule_work(&sdev->requeue_work);
|
|
else
|
|
blk_mq_start_stopped_hw_queues(q, true);
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
if (bidi_bytes)
|
|
scsi_release_bidi_buffers(cmd);
|
|
scsi_release_buffers(cmd);
|
|
scsi_put_command(cmd);
|
|
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
blk_finish_request(req, error);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
|
|
scsi_run_queue(q);
|
|
}
|
|
|
|
put_device(&sdev->sdev_gendev);
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* __scsi_error_from_host_byte - translate SCSI error code into errno
|
|
* @cmd: SCSI command (unused)
|
|
* @result: scsi error code
|
|
*
|
|
* Translate SCSI error code into standard UNIX errno.
|
|
* Return values:
|
|
* -ENOLINK temporary transport failure
|
|
* -EREMOTEIO permanent target failure, do not retry
|
|
* -EBADE permanent nexus failure, retry on other path
|
|
* -ENOSPC No write space available
|
|
* -ENODATA Medium error
|
|
* -EIO unspecified I/O error
|
|
*/
|
|
static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
|
|
{
|
|
int error = 0;
|
|
|
|
switch(host_byte(result)) {
|
|
case DID_TRANSPORT_FAILFAST:
|
|
error = -ENOLINK;
|
|
break;
|
|
case DID_TARGET_FAILURE:
|
|
set_host_byte(cmd, DID_OK);
|
|
error = -EREMOTEIO;
|
|
break;
|
|
case DID_NEXUS_FAILURE:
|
|
set_host_byte(cmd, DID_OK);
|
|
error = -EBADE;
|
|
break;
|
|
case DID_ALLOC_FAILURE:
|
|
set_host_byte(cmd, DID_OK);
|
|
error = -ENOSPC;
|
|
break;
|
|
case DID_MEDIUM_ERROR:
|
|
set_host_byte(cmd, DID_OK);
|
|
error = -ENODATA;
|
|
break;
|
|
default:
|
|
error = -EIO;
|
|
break;
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_io_completion()
|
|
*
|
|
* Purpose: Completion processing for block device I/O requests.
|
|
*
|
|
* Arguments: cmd - command that is finished.
|
|
*
|
|
* Lock status: Assumed that no lock is held upon entry.
|
|
*
|
|
* Returns: Nothing
|
|
*
|
|
* Notes: We will finish off the specified number of sectors. If we
|
|
* are done, the command block will be released and the queue
|
|
* function will be goosed. If we are not done then we have to
|
|
* figure out what to do next:
|
|
*
|
|
* a) We can call scsi_requeue_command(). The request
|
|
* will be unprepared and put back on the queue. Then
|
|
* a new command will be created for it. This should
|
|
* be used if we made forward progress, or if we want
|
|
* to switch from READ(10) to READ(6) for example.
|
|
*
|
|
* b) We can call __scsi_queue_insert(). The request will
|
|
* be put back on the queue and retried using the same
|
|
* command as before, possibly after a delay.
|
|
*
|
|
* c) We can call scsi_end_request() with -EIO to fail
|
|
* the remainder of the request.
|
|
*/
|
|
void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
|
|
{
|
|
int result = cmd->result;
|
|
struct request_queue *q = cmd->device->request_queue;
|
|
struct request *req = cmd->request;
|
|
int error = 0;
|
|
struct scsi_sense_hdr sshdr;
|
|
bool sense_valid = false;
|
|
int sense_deferred = 0, level = 0;
|
|
enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
|
|
ACTION_DELAYED_RETRY} action;
|
|
unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
|
|
|
|
if (result) {
|
|
sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
|
|
if (sense_valid)
|
|
sense_deferred = scsi_sense_is_deferred(&sshdr);
|
|
}
|
|
|
|
if (blk_rq_is_passthrough(req)) {
|
|
if (result) {
|
|
if (sense_valid) {
|
|
/*
|
|
* SG_IO wants current and deferred errors
|
|
*/
|
|
scsi_req(req)->sense_len =
|
|
min(8 + cmd->sense_buffer[7],
|
|
SCSI_SENSE_BUFFERSIZE);
|
|
}
|
|
if (!sense_deferred)
|
|
error = __scsi_error_from_host_byte(cmd, result);
|
|
}
|
|
/*
|
|
* __scsi_error_from_host_byte may have reset the host_byte
|
|
*/
|
|
req->errors = cmd->result;
|
|
|
|
scsi_req(req)->resid_len = scsi_get_resid(cmd);
|
|
|
|
if (scsi_bidi_cmnd(cmd)) {
|
|
/*
|
|
* Bidi commands Must be complete as a whole,
|
|
* both sides at once.
|
|
*/
|
|
scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid;
|
|
if (scsi_end_request(req, 0, blk_rq_bytes(req),
|
|
blk_rq_bytes(req->next_rq)))
|
|
BUG();
|
|
return;
|
|
}
|
|
} else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) {
|
|
/*
|
|
* Flush commands do not transfers any data, and thus cannot use
|
|
* good_bytes != blk_rq_bytes(req) as the signal for an error.
|
|
* This sets the error explicitly for the problem case.
|
|
*/
|
|
error = __scsi_error_from_host_byte(cmd, result);
|
|
}
|
|
|
|
/* no bidi support for !blk_rq_is_passthrough yet */
|
|
BUG_ON(blk_bidi_rq(req));
|
|
|
|
/*
|
|
* Next deal with any sectors which we were able to correctly
|
|
* handle.
|
|
*/
|
|
SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd,
|
|
"%u sectors total, %d bytes done.\n",
|
|
blk_rq_sectors(req), good_bytes));
|
|
|
|
/*
|
|
* Recovered errors need reporting, but they're always treated as
|
|
* success, so fiddle the result code here. For passthrough requests
|
|
* we already took a copy of the original into rq->errors which
|
|
* is what gets returned to the user
|
|
*/
|
|
if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
|
|
/* if ATA PASS-THROUGH INFORMATION AVAILABLE skip
|
|
* print since caller wants ATA registers. Only occurs on
|
|
* SCSI ATA PASS_THROUGH commands when CK_COND=1
|
|
*/
|
|
if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
|
|
;
|
|
else if (!(req->rq_flags & RQF_QUIET))
|
|
scsi_print_sense(cmd);
|
|
result = 0;
|
|
/* for passthrough error may be set */
|
|
error = 0;
|
|
}
|
|
|
|
/*
|
|
* special case: failed zero length commands always need to
|
|
* drop down into the retry code. Otherwise, if we finished
|
|
* all bytes in the request we are done now.
|
|
*/
|
|
if (!(blk_rq_bytes(req) == 0 && error) &&
|
|
!scsi_end_request(req, error, good_bytes, 0))
|
|
return;
|
|
|
|
/*
|
|
* Kill remainder if no retrys.
|
|
*/
|
|
if (error && scsi_noretry_cmd(cmd)) {
|
|
if (scsi_end_request(req, error, blk_rq_bytes(req), 0))
|
|
BUG();
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If there had been no error, but we have leftover bytes in the
|
|
* requeues just queue the command up again.
|
|
*/
|
|
if (result == 0)
|
|
goto requeue;
|
|
|
|
error = __scsi_error_from_host_byte(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_deferred) {
|
|
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;
|
|
error = -EILSEQ;
|
|
/* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
|
|
} else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
|
|
action = ACTION_FAIL;
|
|
error = -EREMOTEIO;
|
|
} else
|
|
action = ACTION_FAIL;
|
|
break;
|
|
case ABORTED_COMMAND:
|
|
action = ACTION_FAIL;
|
|
if (sshdr.asc == 0x10) /* DIF */
|
|
error = -EILSEQ;
|
|
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 0x14: /* space allocation 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;
|
|
default:
|
|
action = ACTION_FAIL;
|
|
break;
|
|
}
|
|
} else
|
|
action = ACTION_FAIL;
|
|
|
|
if (action != ACTION_FAIL &&
|
|
time_before(cmd->jiffies_at_alloc + wait_for, jiffies))
|
|
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, error, blk_rq_err_bytes(req), 0))
|
|
return;
|
|
/*FALLTHRU*/
|
|
case ACTION_REPREP:
|
|
requeue:
|
|
/* Unprep the request and put it back at the head of the queue.
|
|
* A new command will be prepared and issued.
|
|
*/
|
|
if (q->mq_ops) {
|
|
cmd->request->rq_flags &= ~RQF_DONTPREP;
|
|
scsi_mq_uninit_cmd(cmd);
|
|
scsi_mq_requeue_cmd(cmd);
|
|
} else {
|
|
scsi_release_buffers(cmd);
|
|
scsi_requeue_command(q, cmd);
|
|
}
|
|
break;
|
|
case ACTION_RETRY:
|
|
/* Retry the same command immediately */
|
|
__scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
|
|
break;
|
|
case ACTION_DELAYED_RETRY:
|
|
/* Retry the same command after a delay */
|
|
__scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
|
|
{
|
|
int count;
|
|
|
|
/*
|
|
* If sg table allocation fails, requeue request later.
|
|
*/
|
|
if (unlikely(sg_alloc_table_chained(&sdb->table,
|
|
blk_rq_nr_phys_segments(req), sdb->table.sgl)))
|
|
return BLKPREP_DEFER;
|
|
|
|
/*
|
|
* Next, walk the list, and fill in the addresses and sizes of
|
|
* each segment.
|
|
*/
|
|
count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
|
|
BUG_ON(count > sdb->table.nents);
|
|
sdb->table.nents = count;
|
|
sdb->length = blk_rq_payload_bytes(req);
|
|
return BLKPREP_OK;
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_init_io()
|
|
*
|
|
* Purpose: SCSI I/O initialize function.
|
|
*
|
|
* Arguments: cmd - Command descriptor we wish to initialize
|
|
*
|
|
* Returns: 0 on success
|
|
* BLKPREP_DEFER if the failure is retryable
|
|
* BLKPREP_KILL if the failure is fatal
|
|
*/
|
|
int scsi_init_io(struct scsi_cmnd *cmd)
|
|
{
|
|
struct scsi_device *sdev = cmd->device;
|
|
struct request *rq = cmd->request;
|
|
bool is_mq = (rq->mq_ctx != NULL);
|
|
int error;
|
|
|
|
if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq)))
|
|
return -EINVAL;
|
|
|
|
error = scsi_init_sgtable(rq, &cmd->sdb);
|
|
if (error)
|
|
goto err_exit;
|
|
|
|
if (blk_bidi_rq(rq)) {
|
|
if (!rq->q->mq_ops) {
|
|
struct scsi_data_buffer *bidi_sdb =
|
|
kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC);
|
|
if (!bidi_sdb) {
|
|
error = BLKPREP_DEFER;
|
|
goto err_exit;
|
|
}
|
|
|
|
rq->next_rq->special = bidi_sdb;
|
|
}
|
|
|
|
error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special);
|
|
if (error)
|
|
goto err_exit;
|
|
}
|
|
|
|
if (blk_integrity_rq(rq)) {
|
|
struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
|
|
int ivecs, count;
|
|
|
|
if (prot_sdb == NULL) {
|
|
/*
|
|
* This can happen if someone (e.g. multipath)
|
|
* queues a command to a device on an adapter
|
|
* that does not support DIX.
|
|
*/
|
|
WARN_ON_ONCE(1);
|
|
error = BLKPREP_KILL;
|
|
goto err_exit;
|
|
}
|
|
|
|
ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
|
|
|
|
if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
|
|
prot_sdb->table.sgl)) {
|
|
error = BLKPREP_DEFER;
|
|
goto err_exit;
|
|
}
|
|
|
|
count = blk_rq_map_integrity_sg(rq->q, rq->bio,
|
|
prot_sdb->table.sgl);
|
|
BUG_ON(unlikely(count > ivecs));
|
|
BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q)));
|
|
|
|
cmd->prot_sdb = prot_sdb;
|
|
cmd->prot_sdb->table.nents = count;
|
|
}
|
|
|
|
return BLKPREP_OK;
|
|
err_exit:
|
|
if (is_mq) {
|
|
scsi_mq_free_sgtables(cmd);
|
|
} else {
|
|
scsi_release_buffers(cmd);
|
|
cmd->request->special = NULL;
|
|
scsi_put_command(cmd);
|
|
put_device(&sdev->sdev_gendev);
|
|
}
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL(scsi_init_io);
|
|
|
|
void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
|
|
{
|
|
void *buf = cmd->sense_buffer;
|
|
void *prot = cmd->prot_sdb;
|
|
unsigned long flags;
|
|
|
|
/* zero out the cmd, except for the embedded scsi_request */
|
|
memset((char *)cmd + sizeof(cmd->req), 0,
|
|
sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size);
|
|
|
|
cmd->device = dev;
|
|
cmd->sense_buffer = buf;
|
|
cmd->prot_sdb = prot;
|
|
INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
|
|
cmd->jiffies_at_alloc = jiffies;
|
|
|
|
spin_lock_irqsave(&dev->list_lock, flags);
|
|
list_add_tail(&cmd->list, &dev->cmd_list);
|
|
spin_unlock_irqrestore(&dev->list_lock, flags);
|
|
}
|
|
|
|
static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
|
|
{
|
|
struct scsi_cmnd *cmd = req->special;
|
|
|
|
/*
|
|
* 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) {
|
|
int ret = scsi_init_io(cmd);
|
|
if (unlikely(ret))
|
|
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 = req->retries;
|
|
return BLKPREP_OK;
|
|
}
|
|
|
|
/*
|
|
* Setup a normal block command. These are simple request from filesystems
|
|
* that still need to be translated to SCSI CDBs from the ULD.
|
|
*/
|
|
static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
|
|
{
|
|
struct scsi_cmnd *cmd = req->special;
|
|
|
|
if (unlikely(sdev->handler && sdev->handler->prep_fn)) {
|
|
int ret = sdev->handler->prep_fn(sdev, req);
|
|
if (ret != BLKPREP_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 int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req)
|
|
{
|
|
struct scsi_cmnd *cmd = req->special;
|
|
|
|
if (!blk_rq_bytes(req))
|
|
cmd->sc_data_direction = DMA_NONE;
|
|
else if (rq_data_dir(req) == WRITE)
|
|
cmd->sc_data_direction = DMA_TO_DEVICE;
|
|
else
|
|
cmd->sc_data_direction = DMA_FROM_DEVICE;
|
|
|
|
if (blk_rq_is_scsi(req))
|
|
return scsi_setup_scsi_cmnd(sdev, req);
|
|
else
|
|
return scsi_setup_fs_cmnd(sdev, req);
|
|
}
|
|
|
|
static int
|
|
scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
|
|
{
|
|
int ret = BLKPREP_OK;
|
|
|
|
/*
|
|
* If the device is not in running state we will reject some
|
|
* or all commands.
|
|
*/
|
|
if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
|
|
switch (sdev->sdev_state) {
|
|
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.
|
|
*/
|
|
sdev_printk(KERN_ERR, sdev,
|
|
"rejecting I/O to offline device\n");
|
|
ret = BLKPREP_KILL;
|
|
break;
|
|
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");
|
|
ret = BLKPREP_KILL;
|
|
break;
|
|
case SDEV_BLOCK:
|
|
case SDEV_CREATED_BLOCK:
|
|
ret = BLKPREP_DEFER;
|
|
break;
|
|
case SDEV_QUIESCE:
|
|
/*
|
|
* If the devices is blocked we defer normal commands.
|
|
*/
|
|
if (!(req->rq_flags & RQF_PREEMPT))
|
|
ret = BLKPREP_DEFER;
|
|
break;
|
|
default:
|
|
/*
|
|
* For any other not fully online state we only allow
|
|
* special commands. In particular any user initiated
|
|
* command is not allowed.
|
|
*/
|
|
if (!(req->rq_flags & RQF_PREEMPT))
|
|
ret = BLKPREP_KILL;
|
|
break;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
scsi_prep_return(struct request_queue *q, struct request *req, int ret)
|
|
{
|
|
struct scsi_device *sdev = q->queuedata;
|
|
|
|
switch (ret) {
|
|
case BLKPREP_KILL:
|
|
case BLKPREP_INVALID:
|
|
req->errors = DID_NO_CONNECT << 16;
|
|
/* release the command and kill it */
|
|
if (req->special) {
|
|
struct scsi_cmnd *cmd = req->special;
|
|
scsi_release_buffers(cmd);
|
|
scsi_put_command(cmd);
|
|
put_device(&sdev->sdev_gendev);
|
|
req->special = NULL;
|
|
}
|
|
break;
|
|
case BLKPREP_DEFER:
|
|
/*
|
|
* If we defer, the blk_peek_request() returns NULL, but the
|
|
* queue must be restarted, so we schedule a callback to happen
|
|
* shortly.
|
|
*/
|
|
if (atomic_read(&sdev->device_busy) == 0)
|
|
blk_delay_queue(q, SCSI_QUEUE_DELAY);
|
|
break;
|
|
default:
|
|
req->rq_flags |= RQF_DONTPREP;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int scsi_prep_fn(struct request_queue *q, struct request *req)
|
|
{
|
|
struct scsi_device *sdev = q->queuedata;
|
|
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
|
|
int ret;
|
|
|
|
ret = scsi_prep_state_check(sdev, req);
|
|
if (ret != BLKPREP_OK)
|
|
goto out;
|
|
|
|
if (!req->special) {
|
|
/* Bail if we can't get a reference to the device */
|
|
if (unlikely(!get_device(&sdev->sdev_gendev))) {
|
|
ret = BLKPREP_DEFER;
|
|
goto out;
|
|
}
|
|
|
|
scsi_init_command(sdev, cmd);
|
|
req->special = cmd;
|
|
}
|
|
|
|
cmd->tag = req->tag;
|
|
cmd->request = req;
|
|
cmd->prot_op = SCSI_PROT_NORMAL;
|
|
|
|
ret = scsi_setup_cmnd(sdev, req);
|
|
out:
|
|
return scsi_prep_return(q, req, ret);
|
|
}
|
|
|
|
static void scsi_unprep_fn(struct request_queue *q, struct request *req)
|
|
{
|
|
scsi_uninit_cmd(req->special);
|
|
}
|
|
|
|
/*
|
|
* 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) {
|
|
/*
|
|
* For the MQ case we take care of this in the caller.
|
|
*/
|
|
if (!q->mq_ops)
|
|
blk_delay_queue(q, SCSI_QUEUE_DELAY);
|
|
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)
|
|
{
|
|
unsigned int busy;
|
|
|
|
if (scsi_host_in_recovery(shost))
|
|
return 0;
|
|
|
|
busy = atomic_inc_return(&shost->host_busy) - 1;
|
|
if (atomic_read(&shost->host_blocked) > 0) {
|
|
if (busy)
|
|
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->can_queue > 0 && busy >= shost->can_queue)
|
|
goto starved;
|
|
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);
|
|
}
|
|
|
|
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:
|
|
atomic_dec(&shost->host_busy);
|
|
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 int scsi_lld_busy(struct request_queue *q)
|
|
{
|
|
struct scsi_device *sdev = q->queuedata;
|
|
struct Scsi_Host *shost;
|
|
|
|
if (blk_queue_dying(q))
|
|
return 0;
|
|
|
|
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 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Kill a request for a dead device
|
|
*/
|
|
static void scsi_kill_request(struct request *req, struct request_queue *q)
|
|
{
|
|
struct scsi_cmnd *cmd = req->special;
|
|
struct scsi_device *sdev;
|
|
struct scsi_target *starget;
|
|
struct Scsi_Host *shost;
|
|
|
|
blk_start_request(req);
|
|
|
|
scmd_printk(KERN_INFO, cmd, "killing request\n");
|
|
|
|
sdev = cmd->device;
|
|
starget = scsi_target(sdev);
|
|
shost = sdev->host;
|
|
scsi_init_cmd_errh(cmd);
|
|
cmd->result = DID_NO_CONNECT << 16;
|
|
atomic_inc(&cmd->device->iorequest_cnt);
|
|
|
|
/*
|
|
* SCSI request completion path will do scsi_device_unbusy(),
|
|
* bump busy counts. To bump the counters, we need to dance
|
|
* with the locks as normal issue path does.
|
|
*/
|
|
atomic_inc(&sdev->device_busy);
|
|
atomic_inc(&shost->host_busy);
|
|
if (starget->can_queue > 0)
|
|
atomic_inc(&starget->target_busy);
|
|
|
|
blk_complete_request(req);
|
|
}
|
|
|
|
static void scsi_softirq_done(struct request *rq)
|
|
{
|
|
struct scsi_cmnd *cmd = rq->special;
|
|
unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
|
|
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 &&
|
|
time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
|
|
sdev_printk(KERN_ERR, cmd->device,
|
|
"timing out command, waited %lus\n",
|
|
wait_for/HZ);
|
|
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:
|
|
if (!scsi_eh_scmd_add(cmd, 0))
|
|
scsi_finish_command(cmd);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
}
|
|
|
|
/**
|
|
* scsi_done - Invoke completion on finished SCSI command.
|
|
* @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
|
|
* ownership back to SCSI Core -- i.e. the LLDD has finished with it.
|
|
*
|
|
* Description: This function is the mid-level's (SCSI Core) interrupt routine,
|
|
* which regains ownership of the SCSI command (de facto) from a LLDD, and
|
|
* calls blk_complete_request() for further processing.
|
|
*
|
|
* This function is interrupt context safe.
|
|
*/
|
|
static void scsi_done(struct scsi_cmnd *cmd)
|
|
{
|
|
trace_scsi_dispatch_cmd_done(cmd);
|
|
blk_complete_request(cmd->request);
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_request_fn()
|
|
*
|
|
* Purpose: Main strategy routine for SCSI.
|
|
*
|
|
* Arguments: q - Pointer to actual queue.
|
|
*
|
|
* Returns: Nothing
|
|
*
|
|
* Lock status: IO request lock assumed to be held when called.
|
|
*/
|
|
static void scsi_request_fn(struct request_queue *q)
|
|
__releases(q->queue_lock)
|
|
__acquires(q->queue_lock)
|
|
{
|
|
struct scsi_device *sdev = q->queuedata;
|
|
struct Scsi_Host *shost;
|
|
struct scsi_cmnd *cmd;
|
|
struct request *req;
|
|
|
|
/*
|
|
* To start with, we keep looping until the queue is empty, or until
|
|
* the host is no longer able to accept any more requests.
|
|
*/
|
|
shost = sdev->host;
|
|
for (;;) {
|
|
int rtn;
|
|
/*
|
|
* get next queueable request. We do this early to make sure
|
|
* that the request is fully prepared even if we cannot
|
|
* accept it.
|
|
*/
|
|
req = blk_peek_request(q);
|
|
if (!req)
|
|
break;
|
|
|
|
if (unlikely(!scsi_device_online(sdev))) {
|
|
sdev_printk(KERN_ERR, sdev,
|
|
"rejecting I/O to offline device\n");
|
|
scsi_kill_request(req, q);
|
|
continue;
|
|
}
|
|
|
|
if (!scsi_dev_queue_ready(q, sdev))
|
|
break;
|
|
|
|
/*
|
|
* Remove the request from the request list.
|
|
*/
|
|
if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
|
|
blk_start_request(req);
|
|
|
|
spin_unlock_irq(q->queue_lock);
|
|
cmd = req->special;
|
|
if (unlikely(cmd == NULL)) {
|
|
printk(KERN_CRIT "impossible request in %s.\n"
|
|
"please mail a stack trace to "
|
|
"linux-scsi@vger.kernel.org\n",
|
|
__func__);
|
|
blk_dump_rq_flags(req, "foo");
|
|
BUG();
|
|
}
|
|
|
|
/*
|
|
* We hit this when the driver is using a host wide
|
|
* tag map. For device level tag maps the queue_depth check
|
|
* in the device ready fn would prevent us from trying
|
|
* to allocate a tag. Since the map is a shared host resource
|
|
* we add the dev to the starved list so it eventually gets
|
|
* a run when a tag is freed.
|
|
*/
|
|
if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) {
|
|
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);
|
|
goto not_ready;
|
|
}
|
|
|
|
if (!scsi_target_queue_ready(shost, sdev))
|
|
goto not_ready;
|
|
|
|
if (!scsi_host_queue_ready(q, shost, sdev))
|
|
goto host_not_ready;
|
|
|
|
if (sdev->simple_tags)
|
|
cmd->flags |= SCMD_TAGGED;
|
|
else
|
|
cmd->flags &= ~SCMD_TAGGED;
|
|
|
|
/*
|
|
* Finally, initialize any error handling parameters, and set up
|
|
* the timers for timeouts.
|
|
*/
|
|
scsi_init_cmd_errh(cmd);
|
|
|
|
/*
|
|
* Dispatch the command to the low-level driver.
|
|
*/
|
|
cmd->scsi_done = scsi_done;
|
|
rtn = scsi_dispatch_cmd(cmd);
|
|
if (rtn) {
|
|
scsi_queue_insert(cmd, rtn);
|
|
spin_lock_irq(q->queue_lock);
|
|
goto out_delay;
|
|
}
|
|
spin_lock_irq(q->queue_lock);
|
|
}
|
|
|
|
return;
|
|
|
|
host_not_ready:
|
|
if (scsi_target(sdev)->can_queue > 0)
|
|
atomic_dec(&scsi_target(sdev)->target_busy);
|
|
not_ready:
|
|
/*
|
|
* lock q, handle tag, requeue req, and decrement device_busy. We
|
|
* must return with queue_lock held.
|
|
*
|
|
* Decrementing device_busy without checking it is OK, as all such
|
|
* cases (host limits or settings) should run the queue at some
|
|
* later time.
|
|
*/
|
|
spin_lock_irq(q->queue_lock);
|
|
blk_requeue_request(q, req);
|
|
atomic_dec(&sdev->device_busy);
|
|
out_delay:
|
|
if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev))
|
|
blk_delay_queue(q, SCSI_QUEUE_DELAY);
|
|
}
|
|
|
|
static inline int prep_to_mq(int ret)
|
|
{
|
|
switch (ret) {
|
|
case BLKPREP_OK:
|
|
return BLK_MQ_RQ_QUEUE_OK;
|
|
case BLKPREP_DEFER:
|
|
return BLK_MQ_RQ_QUEUE_BUSY;
|
|
default:
|
|
return BLK_MQ_RQ_QUEUE_ERROR;
|
|
}
|
|
}
|
|
|
|
static int scsi_mq_prep_fn(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;
|
|
unsigned char *sense_buf = cmd->sense_buffer;
|
|
struct scatterlist *sg;
|
|
|
|
/* zero out the cmd, except for the embedded scsi_request */
|
|
memset((char *)cmd + sizeof(cmd->req), 0,
|
|
sizeof(*cmd) - sizeof(cmd->req));
|
|
|
|
req->special = cmd;
|
|
|
|
cmd->request = req;
|
|
cmd->device = sdev;
|
|
cmd->sense_buffer = sense_buf;
|
|
|
|
cmd->tag = req->tag;
|
|
|
|
cmd->prot_op = SCSI_PROT_NORMAL;
|
|
|
|
INIT_LIST_HEAD(&cmd->list);
|
|
INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
|
|
cmd->jiffies_at_alloc = jiffies;
|
|
|
|
if (shost->use_cmd_list) {
|
|
spin_lock_irq(&sdev->list_lock);
|
|
list_add_tail(&cmd->list, &sdev->cmd_list);
|
|
spin_unlock_irq(&sdev->list_lock);
|
|
}
|
|
|
|
sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
|
|
cmd->sdb.table.sgl = sg;
|
|
|
|
if (scsi_host_get_prot(shost)) {
|
|
cmd->prot_sdb = (void *)sg +
|
|
min_t(unsigned int,
|
|
shost->sg_tablesize, SG_CHUNK_SIZE) *
|
|
sizeof(struct scatterlist);
|
|
memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
|
|
|
|
cmd->prot_sdb->table.sgl =
|
|
(struct scatterlist *)(cmd->prot_sdb + 1);
|
|
}
|
|
|
|
if (blk_bidi_rq(req)) {
|
|
struct request *next_rq = req->next_rq;
|
|
struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq);
|
|
|
|
memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer));
|
|
bidi_sdb->table.sgl =
|
|
(struct scatterlist *)(bidi_sdb + 1);
|
|
|
|
next_rq->special = bidi_sdb;
|
|
}
|
|
|
|
blk_mq_start_request(req);
|
|
|
|
return scsi_setup_cmnd(sdev, req);
|
|
}
|
|
|
|
static void scsi_mq_done(struct scsi_cmnd *cmd)
|
|
{
|
|
trace_scsi_dispatch_cmd_done(cmd);
|
|
blk_mq_complete_request(cmd->request, cmd->request->errors);
|
|
}
|
|
|
|
static int 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);
|
|
int ret;
|
|
int reason;
|
|
|
|
ret = prep_to_mq(scsi_prep_state_check(sdev, req));
|
|
if (ret != BLK_MQ_RQ_QUEUE_OK)
|
|
goto out;
|
|
|
|
ret = BLK_MQ_RQ_QUEUE_BUSY;
|
|
if (!get_device(&sdev->sdev_gendev))
|
|
goto out;
|
|
|
|
if (!scsi_dev_queue_ready(q, sdev))
|
|
goto out_put_device;
|
|
if (!scsi_target_queue_ready(shost, sdev))
|
|
goto out_dec_device_busy;
|
|
if (!scsi_host_queue_ready(q, shost, sdev))
|
|
goto out_dec_target_busy;
|
|
|
|
if (!(req->rq_flags & RQF_DONTPREP)) {
|
|
ret = prep_to_mq(scsi_mq_prep_fn(req));
|
|
if (ret != BLK_MQ_RQ_QUEUE_OK)
|
|
goto out_dec_host_busy;
|
|
req->rq_flags |= RQF_DONTPREP;
|
|
} else {
|
|
blk_mq_start_request(req);
|
|
}
|
|
|
|
if (sdev->simple_tags)
|
|
cmd->flags |= SCMD_TAGGED;
|
|
else
|
|
cmd->flags &= ~SCMD_TAGGED;
|
|
|
|
scsi_init_cmd_errh(cmd);
|
|
cmd->scsi_done = scsi_mq_done;
|
|
|
|
reason = scsi_dispatch_cmd(cmd);
|
|
if (reason) {
|
|
scsi_set_blocked(cmd, reason);
|
|
ret = BLK_MQ_RQ_QUEUE_BUSY;
|
|
goto out_dec_host_busy;
|
|
}
|
|
|
|
return BLK_MQ_RQ_QUEUE_OK;
|
|
|
|
out_dec_host_busy:
|
|
atomic_dec(&shost->host_busy);
|
|
out_dec_target_busy:
|
|
if (scsi_target(sdev)->can_queue > 0)
|
|
atomic_dec(&scsi_target(sdev)->target_busy);
|
|
out_dec_device_busy:
|
|
atomic_dec(&sdev->device_busy);
|
|
out_put_device:
|
|
put_device(&sdev->sdev_gendev);
|
|
out:
|
|
switch (ret) {
|
|
case BLK_MQ_RQ_QUEUE_BUSY:
|
|
if (atomic_read(&sdev->device_busy) == 0 &&
|
|
!scsi_device_blocked(sdev))
|
|
blk_mq_delay_queue(hctx, SCSI_QUEUE_DELAY);
|
|
break;
|
|
case BLK_MQ_RQ_QUEUE_ERROR:
|
|
/*
|
|
* Make sure to release all allocated ressources when
|
|
* we hit an error, as we will never see this command
|
|
* again.
|
|
*/
|
|
if (req->rq_flags & RQF_DONTPREP)
|
|
scsi_mq_uninit_cmd(cmd);
|
|
break;
|
|
default:
|
|
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_init_request(void *data, struct request *rq,
|
|
unsigned int hctx_idx, unsigned int request_idx,
|
|
unsigned int numa_node)
|
|
{
|
|
struct Scsi_Host *shost = data;
|
|
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
|
|
|
|
cmd->sense_buffer =
|
|
scsi_alloc_sense_buffer(shost, GFP_KERNEL, numa_node);
|
|
if (!cmd->sense_buffer)
|
|
return -ENOMEM;
|
|
cmd->req.sense = cmd->sense_buffer;
|
|
return 0;
|
|
}
|
|
|
|
static void scsi_exit_request(void *data, struct request *rq,
|
|
unsigned int hctx_idx, unsigned int request_idx)
|
|
{
|
|
struct Scsi_Host *shost = data;
|
|
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
|
|
|
|
scsi_free_sense_buffer(shost, 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);
|
|
}
|
|
|
|
static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)
|
|
{
|
|
struct device *host_dev;
|
|
u64 bounce_limit = 0xffffffff;
|
|
|
|
if (shost->unchecked_isa_dma)
|
|
return BLK_BOUNCE_ISA;
|
|
/*
|
|
* Platforms with virtual-DMA translation
|
|
* hardware have no practical limit.
|
|
*/
|
|
if (!PCI_DMA_BUS_IS_PHYS)
|
|
return BLK_BOUNCE_ANY;
|
|
|
|
host_dev = scsi_get_device(shost);
|
|
if (host_dev && host_dev->dma_mask)
|
|
bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT;
|
|
|
|
return bounce_limit;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
blk_queue_max_hw_sectors(q, shost->max_sectors);
|
|
blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
|
|
blk_queue_segment_boundary(q, shost->dma_boundary);
|
|
dma_set_seg_boundary(dev, shost->dma_boundary);
|
|
|
|
blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
|
|
|
|
if (!shost->use_clustering)
|
|
q->limits.cluster = 0;
|
|
|
|
/*
|
|
* set a reasonable default alignment on word boundaries: the
|
|
* host and device may alter it using
|
|
* blk_queue_update_dma_alignment() later.
|
|
*/
|
|
blk_queue_dma_alignment(q, 0x03);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__scsi_init_queue);
|
|
|
|
static int scsi_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
|
|
{
|
|
struct Scsi_Host *shost = q->rq_alloc_data;
|
|
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
|
|
|
|
memset(cmd, 0, sizeof(*cmd));
|
|
|
|
cmd->sense_buffer = scsi_alloc_sense_buffer(shost, gfp, NUMA_NO_NODE);
|
|
if (!cmd->sense_buffer)
|
|
goto fail;
|
|
cmd->req.sense = cmd->sense_buffer;
|
|
|
|
if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
|
|
cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp);
|
|
if (!cmd->prot_sdb)
|
|
goto fail_free_sense;
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail_free_sense:
|
|
scsi_free_sense_buffer(shost, cmd->sense_buffer);
|
|
fail:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static void scsi_exit_rq(struct request_queue *q, struct request *rq)
|
|
{
|
|
struct Scsi_Host *shost = q->rq_alloc_data;
|
|
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
|
|
|
|
if (cmd->prot_sdb)
|
|
kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
|
|
scsi_free_sense_buffer(shost, cmd->sense_buffer);
|
|
}
|
|
|
|
struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
|
|
{
|
|
struct Scsi_Host *shost = sdev->host;
|
|
struct request_queue *q;
|
|
|
|
q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE);
|
|
if (!q)
|
|
return NULL;
|
|
q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
|
|
q->rq_alloc_data = shost;
|
|
q->request_fn = scsi_request_fn;
|
|
q->init_rq_fn = scsi_init_rq;
|
|
q->exit_rq_fn = scsi_exit_rq;
|
|
|
|
if (blk_init_allocated_queue(q) < 0) {
|
|
blk_cleanup_queue(q);
|
|
return NULL;
|
|
}
|
|
|
|
__scsi_init_queue(shost, q);
|
|
blk_queue_prep_rq(q, scsi_prep_fn);
|
|
blk_queue_unprep_rq(q, scsi_unprep_fn);
|
|
blk_queue_softirq_done(q, scsi_softirq_done);
|
|
blk_queue_rq_timed_out(q, scsi_times_out);
|
|
blk_queue_lld_busy(q, scsi_lld_busy);
|
|
return q;
|
|
}
|
|
|
|
static struct blk_mq_ops scsi_mq_ops = {
|
|
.queue_rq = scsi_queue_rq,
|
|
.complete = scsi_softirq_done,
|
|
.timeout = scsi_timeout,
|
|
.init_request = scsi_init_request,
|
|
.exit_request = scsi_exit_request,
|
|
.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);
|
|
return sdev->request_queue;
|
|
}
|
|
|
|
int scsi_mq_setup_tags(struct Scsi_Host *shost)
|
|
{
|
|
unsigned int cmd_size, sgl_size, tbl_size;
|
|
|
|
tbl_size = shost->sg_tablesize;
|
|
if (tbl_size > SG_CHUNK_SIZE)
|
|
tbl_size = SG_CHUNK_SIZE;
|
|
sgl_size = tbl_size * sizeof(struct scatterlist);
|
|
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) + sgl_size;
|
|
|
|
memset(&shost->tag_set, 0, sizeof(shost->tag_set));
|
|
shost->tag_set.ops = &scsi_mq_ops;
|
|
shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1;
|
|
shost->tag_set.queue_depth = shost->can_queue;
|
|
shost->tag_set.cmd_size = cmd_size;
|
|
shost->tag_set.numa_node = NUMA_NO_NODE;
|
|
shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
|
|
shost->tag_set.flags |=
|
|
BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
|
|
shost->tag_set.driver_data = shost;
|
|
|
|
return blk_mq_alloc_tag_set(&shost->tag_set);
|
|
}
|
|
|
|
void scsi_mq_destroy_tags(struct Scsi_Host *shost)
|
|
{
|
|
blk_mq_free_tag_set(&shost->tag_set);
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_block_requests()
|
|
*
|
|
* Purpose: Utility function used by low-level drivers to prevent further
|
|
* commands from being queued to the device.
|
|
*
|
|
* Arguments: shost - Host in question
|
|
*
|
|
* Returns: Nothing
|
|
*
|
|
* Lock status: No locks are assumed held.
|
|
*
|
|
* Notes: 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);
|
|
|
|
/*
|
|
* Function: scsi_unblock_requests()
|
|
*
|
|
* Purpose: Utility function used by low-level drivers to allow further
|
|
* commands from being queued to the device.
|
|
*
|
|
* Arguments: shost - Host in question
|
|
*
|
|
* Returns: Nothing
|
|
*
|
|
* Lock status: No locks are assumed held.
|
|
*
|
|
* Notes: 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);
|
|
|
|
int __init scsi_init_queue(void)
|
|
{
|
|
scsi_sdb_cache = kmem_cache_create("scsi_data_buffer",
|
|
sizeof(struct scsi_data_buffer),
|
|
0, 0, NULL);
|
|
if (!scsi_sdb_cache) {
|
|
printk(KERN_ERR "SCSI: can't init scsi sdb cache\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void scsi_exit_queue(void)
|
|
{
|
|
kmem_cache_destroy(scsi_sense_cache);
|
|
kmem_cache_destroy(scsi_sense_isadma_cache);
|
|
kmem_cache_destroy(scsi_sdb_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 unsuccessful, or the header offset (either 4
|
|
* or 8 depending on whether a six or ten byte command was
|
|
* issued) if successful.
|
|
*/
|
|
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);
|
|
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);
|
|
|
|
/* 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;
|
|
} else if ((status_byte(result) == CHECK_CONDITION) &&
|
|
scsi_sense_valid(sshdr) &&
|
|
sshdr->sense_key == UNIT_ATTENTION && retry_count) {
|
|
retry_count--;
|
|
goto retry;
|
|
}
|
|
|
|
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_external: Optional pointer to struct scsi_sense_hdr for
|
|
* returning sense. Make sure that this is cleared before passing
|
|
* in.
|
|
*
|
|
* 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_external)
|
|
{
|
|
char cmd[] = {
|
|
TEST_UNIT_READY, 0, 0, 0, 0, 0,
|
|
};
|
|
struct scsi_sense_hdr *sshdr;
|
|
int result;
|
|
|
|
if (!sshdr_external)
|
|
sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
|
|
else
|
|
sshdr = sshdr_external;
|
|
|
|
/* try to eat the UNIT_ATTENTION if there are enough retries */
|
|
do {
|
|
result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
|
|
timeout, retries, 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);
|
|
|
|
if (!sshdr_external)
|
|
kfree(sshdr);
|
|
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 unsuccessful 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:
|
|
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:
|
|
case SDEV_BLOCK:
|
|
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_CREATED_BLOCK:
|
|
break;
|
|
default:
|
|
goto illegal;
|
|
}
|
|
break;
|
|
|
|
}
|
|
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;
|
|
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:
|
|
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_request_fn_active() - number of kernel threads inside scsi_request_fn()
|
|
* @sdev: SCSI device to count the number of scsi_request_fn() callers for.
|
|
*/
|
|
static int scsi_request_fn_active(struct scsi_device *sdev)
|
|
{
|
|
struct request_queue *q = sdev->request_queue;
|
|
int request_fn_active;
|
|
|
|
WARN_ON_ONCE(sdev->host->use_blk_mq);
|
|
|
|
spin_lock_irq(q->queue_lock);
|
|
request_fn_active = q->request_fn_active;
|
|
spin_unlock_irq(q->queue_lock);
|
|
|
|
return request_fn_active;
|
|
}
|
|
|
|
/**
|
|
* scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls
|
|
* @sdev: SCSI device pointer.
|
|
*
|
|
* Wait until the ongoing shost->hostt->queuecommand() calls that are
|
|
* invoked from scsi_request_fn() have finished.
|
|
*/
|
|
static void scsi_wait_for_queuecommand(struct scsi_device *sdev)
|
|
{
|
|
WARN_ON_ONCE(sdev->host->use_blk_mq);
|
|
|
|
while (scsi_request_fn_active(sdev))
|
|
msleep(20);
|
|
}
|
|
|
|
/**
|
|
* scsi_device_quiesce - Block user issued commands.
|
|
* @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 special requests will be accepted, all others will
|
|
* be deferred. Since special requests may also be requeued requests,
|
|
* a successful return doesn't guarantee the device will be
|
|
* totally quiescent.
|
|
*
|
|
* 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)
|
|
{
|
|
int err = scsi_device_set_state(sdev, SDEV_QUIESCE);
|
|
if (err)
|
|
return err;
|
|
|
|
scsi_run_queue(sdev->request_queue);
|
|
while (atomic_read(&sdev->device_busy)) {
|
|
msleep_interruptible(200);
|
|
scsi_run_queue(sdev->request_queue);
|
|
}
|
|
return 0;
|
|
}
|
|
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)
|
|
*/
|
|
if (sdev->sdev_state != SDEV_QUIESCE ||
|
|
scsi_device_set_state(sdev, SDEV_RUNNING))
|
|
return;
|
|
scsi_run_queue(sdev->request_queue);
|
|
}
|
|
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 - internal function to put a device temporarily into the SDEV_BLOCK state
|
|
* @sdev: device to block
|
|
*
|
|
* Block request made by scsi lld's to temporarily stop all
|
|
* scsi commands on the specified device. May sleep.
|
|
*
|
|
* Returns zero if successful or error if not
|
|
*
|
|
* Notes:
|
|
* This routine transitions the device to the SDEV_BLOCK state
|
|
* (which must be a legal transition). When the device is in this
|
|
* state, all commands are deferred until the scsi lld reenables
|
|
* the device with scsi_device_unblock or device_block_tmo fires.
|
|
*
|
|
* To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after
|
|
* scsi_internal_device_block() has blocked a SCSI device and also
|
|
* remove the rport mutex lock and unlock calls from srp_queuecommand().
|
|
*/
|
|
int
|
|
scsi_internal_device_block(struct scsi_device *sdev)
|
|
{
|
|
struct request_queue *q = sdev->request_queue;
|
|
unsigned long flags;
|
|
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.
|
|
*/
|
|
if (q->mq_ops) {
|
|
blk_mq_quiesce_queue(q);
|
|
} else {
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
blk_stop_queue(q);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
scsi_wait_for_queuecommand(sdev);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(scsi_internal_device_block);
|
|
|
|
/**
|
|
* scsi_internal_device_unblock - resume a device after a block request
|
|
* @sdev: device to resume
|
|
* @new_state: state to set devices to after unblocking
|
|
*
|
|
* Called by scsi lld's or the midlayer to restart the device queue
|
|
* for the previously suspended scsi device. Called from interrupt or
|
|
* normal process context.
|
|
*
|
|
* Returns zero if successful or error if not.
|
|
*
|
|
* 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(struct scsi_device *sdev,
|
|
enum scsi_device_state new_state)
|
|
{
|
|
struct request_queue *q = sdev->request_queue;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Try to transition the scsi device to SDEV_RUNNING or one of the
|
|
* offlined states and goose the device queue if successful.
|
|
*/
|
|
if ((sdev->sdev_state == SDEV_BLOCK) ||
|
|
(sdev->sdev_state == SDEV_TRANSPORT_OFFLINE))
|
|
sdev->sdev_state = new_state;
|
|
else if (sdev->sdev_state == SDEV_CREATED_BLOCK) {
|
|
if (new_state == SDEV_TRANSPORT_OFFLINE ||
|
|
new_state == SDEV_OFFLINE)
|
|
sdev->sdev_state = new_state;
|
|
else
|
|
sdev->sdev_state = SDEV_CREATED;
|
|
} else if (sdev->sdev_state != SDEV_CANCEL &&
|
|
sdev->sdev_state != SDEV_OFFLINE)
|
|
return -EINVAL;
|
|
|
|
if (q->mq_ops) {
|
|
blk_mq_start_stopped_hw_queues(q, false);
|
|
} else {
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
blk_start_queue(q);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(scsi_internal_device_unblock);
|
|
|
|
static void
|
|
device_block(struct scsi_device *sdev, void *data)
|
|
{
|
|
scsi_internal_device_block(sdev);
|
|
}
|
|
|
|
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);
|
|
|
|
/**
|
|
* 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);
|
|
|
|
/**
|
|
* 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_type = 0xff;
|
|
u8 cur_id_size = 0;
|
|
unsigned char *d, *cur_id_str;
|
|
unsigned char __rcu *vpd_pg83;
|
|
int id_size = -EINVAL;
|
|
|
|
rcu_read_lock();
|
|
vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
|
|
if (!vpd_pg83) {
|
|
rcu_read_unlock();
|
|
return -ENXIO;
|
|
}
|
|
|
|
/*
|
|
* Look for the correct descriptor.
|
|
* 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
|
|
* - T10 Vendor ID
|
|
* as longer descriptors reduce the likelyhood
|
|
* of identification clashes.
|
|
*/
|
|
|
|
/* 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 + 4;
|
|
while (d < vpd_pg83 + sdev->vpd_pg83_len) {
|
|
/* Skip designators not referring to the LUN */
|
|
if ((d[1] & 0x30) != 0x00)
|
|
goto next_desig;
|
|
|
|
switch (d[1] & 0xf) {
|
|
case 0x1:
|
|
/* T10 Vendor ID */
|
|
if (cur_id_size > d[3])
|
|
break;
|
|
/* Prefer anything */
|
|
if (cur_id_type > 0x01 && cur_id_type != 0xff)
|
|
break;
|
|
cur_id_size = d[3];
|
|
if (cur_id_size + 4 > id_len)
|
|
cur_id_size = id_len - 4;
|
|
cur_id_str = d + 4;
|
|
cur_id_type = d[1] & 0xf;
|
|
id_size = snprintf(id, id_len, "t10.%*pE",
|
|
cur_id_size, cur_id_str);
|
|
break;
|
|
case 0x2:
|
|
/* EUI-64 */
|
|
if (cur_id_size > d[3])
|
|
break;
|
|
/* Prefer NAA IEEE Registered Extended */
|
|
if (cur_id_type == 0x3 &&
|
|
cur_id_size == d[3])
|
|
break;
|
|
cur_id_size = d[3];
|
|
cur_id_str = d + 4;
|
|
cur_id_type = d[1] & 0xf;
|
|
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:
|
|
cur_id_size = 0;
|
|
break;
|
|
}
|
|
break;
|
|
case 0x3:
|
|
/* NAA */
|
|
if (cur_id_size > d[3])
|
|
break;
|
|
cur_id_size = d[3];
|
|
cur_id_str = d + 4;
|
|
cur_id_type = d[1] & 0xf;
|
|
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:
|
|
cur_id_size = 0;
|
|
break;
|
|
}
|
|
break;
|
|
case 0x8:
|
|
/* SCSI name string */
|
|
if (cur_id_size + 4 > d[3])
|
|
break;
|
|
/* Prefer others for truncated descriptor */
|
|
if (cur_id_size && d[3] > id_len)
|
|
break;
|
|
cur_id_size = id_size = d[3];
|
|
cur_id_str = d + 4;
|
|
cur_id_type = d[1] & 0xf;
|
|
if (cur_id_size >= id_len)
|
|
cur_id_size = id_len - 1;
|
|
memcpy(id, cur_id_str, cur_id_size);
|
|
/* Decrease priority for truncated descriptor */
|
|
if (cur_id_size != id_size)
|
|
cur_id_size = 6;
|
|
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)
|
|
{
|
|
unsigned char *d;
|
|
unsigned char __rcu *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 = sdev->vpd_pg83 + 4;
|
|
while (d < sdev->vpd_pg83 + sdev->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);
|