![FUJITA Tomonori](/assets/img/avatar_default.png)
scsi_init_queue is expected to clean up allocated things when it fails. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2491 lines
62 KiB
C
2491 lines
62 KiB
C
/*
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* scsi_lib.c Copyright (C) 1999 Eric Youngdale
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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/mempool.h>
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#include <linux/slab.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 <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_priv.h"
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#include "scsi_logging.h"
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#define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools)
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#define SG_MEMPOOL_SIZE 2
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struct scsi_host_sg_pool {
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size_t size;
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char *name;
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struct kmem_cache *slab;
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mempool_t *pool;
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};
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#define SP(x) { x, "sgpool-" __stringify(x) }
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#if (SCSI_MAX_SG_SEGMENTS < 32)
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#error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater)
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#endif
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static struct scsi_host_sg_pool scsi_sg_pools[] = {
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SP(8),
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SP(16),
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#if (SCSI_MAX_SG_SEGMENTS > 32)
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SP(32),
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#if (SCSI_MAX_SG_SEGMENTS > 64)
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SP(64),
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#if (SCSI_MAX_SG_SEGMENTS > 128)
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SP(128),
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#if (SCSI_MAX_SG_SEGMENTS > 256)
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#error SCSI_MAX_SG_SEGMENTS is too large (256 MAX)
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#endif
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#endif
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#endif
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#endif
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SP(SCSI_MAX_SG_SEGMENTS)
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};
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#undef SP
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static struct kmem_cache *scsi_bidi_sdb_cache;
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static void scsi_run_queue(struct request_queue *q);
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/*
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* Function: scsi_unprep_request()
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*
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* Purpose: Remove all preparation done for a request, including its
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* associated scsi_cmnd, so that it can be requeued.
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*
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* Arguments: req - request to unprepare
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*
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* Lock status: Assumed that no locks are held upon entry.
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*
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* Returns: Nothing.
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*/
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static void scsi_unprep_request(struct request *req)
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{
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struct scsi_cmnd *cmd = req->special;
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req->cmd_flags &= ~REQ_DONTPREP;
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req->special = NULL;
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scsi_put_command(cmd);
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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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int scsi_queue_insert(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 request_queue *q = device->request_queue;
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unsigned long flags;
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SCSI_LOG_MLQUEUE(1,
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printk("Inserting command %p into mlqueue\n", cmd));
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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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if (reason == SCSI_MLQUEUE_HOST_BUSY)
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host->host_blocked = host->max_host_blocked;
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else if (reason == SCSI_MLQUEUE_DEVICE_BUSY)
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device->device_blocked = device->max_device_blocked;
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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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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.
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*
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* NOTE: there is magic here about the way the queue is plugged if
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* we have no outstanding commands.
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*
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* Although we *don't* plug the queue, we call the request
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* function. The SCSI request function detects the blocked condition
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* and plugs the queue appropriately.
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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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spin_unlock_irqrestore(q->queue_lock, flags);
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scsi_run_queue(q);
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return 0;
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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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*
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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, int flags)
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{
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struct request *req;
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int write = (data_direction == DMA_TO_DEVICE);
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int ret = DRIVER_ERROR << 24;
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req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);
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if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
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buffer, bufflen, __GFP_WAIT))
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goto out;
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req->cmd_len = COMMAND_SIZE(cmd[0]);
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memcpy(req->cmd, cmd, req->cmd_len);
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req->sense = sense;
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req->sense_len = 0;
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req->retries = retries;
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req->timeout = timeout;
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req->cmd_type = REQ_TYPE_BLOCK_PC;
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req->cmd_flags |= flags | REQ_QUIET | REQ_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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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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EXPORT_SYMBOL(scsi_execute);
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int scsi_execute_req(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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{
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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, 0);
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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);
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struct scsi_io_context {
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void *data;
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void (*done)(void *data, char *sense, int result, int resid);
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char sense[SCSI_SENSE_BUFFERSIZE];
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};
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static struct kmem_cache *scsi_io_context_cache;
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static void scsi_end_async(struct request *req, int uptodate)
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{
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struct scsi_io_context *sioc = req->end_io_data;
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if (sioc->done)
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sioc->done(sioc->data, sioc->sense, req->errors, req->data_len);
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kmem_cache_free(scsi_io_context_cache, sioc);
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__blk_put_request(req->q, req);
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}
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static int scsi_merge_bio(struct request *rq, struct bio *bio)
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{
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struct request_queue *q = rq->q;
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bio->bi_flags &= ~(1 << BIO_SEG_VALID);
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if (rq_data_dir(rq) == WRITE)
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bio->bi_rw |= (1 << BIO_RW);
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blk_queue_bounce(q, &bio);
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return blk_rq_append_bio(q, rq, bio);
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}
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static void scsi_bi_endio(struct bio *bio, int error)
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{
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bio_put(bio);
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}
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/**
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* scsi_req_map_sg - map a scatterlist into a request
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* @rq: request to fill
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* @sgl: scatterlist
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* @nsegs: number of elements
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* @bufflen: len of buffer
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* @gfp: memory allocation flags
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*
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* scsi_req_map_sg maps a scatterlist into a request so that the
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* request can be sent to the block layer. We do not trust the scatterlist
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* sent to use, as some ULDs use that struct to only organize the pages.
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*/
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static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
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int nsegs, unsigned bufflen, gfp_t gfp)
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{
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struct request_queue *q = rq->q;
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int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
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unsigned int data_len = bufflen, len, bytes, off;
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struct scatterlist *sg;
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struct page *page;
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struct bio *bio = NULL;
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int i, err, nr_vecs = 0;
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for_each_sg(sgl, sg, nsegs, i) {
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page = sg_page(sg);
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off = sg->offset;
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len = sg->length;
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data_len += len;
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while (len > 0 && data_len > 0) {
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/*
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* sg sends a scatterlist that is larger than
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* the data_len it wants transferred for certain
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* IO sizes
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*/
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bytes = min_t(unsigned int, len, PAGE_SIZE - off);
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bytes = min(bytes, data_len);
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if (!bio) {
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nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
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nr_pages -= nr_vecs;
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bio = bio_alloc(gfp, nr_vecs);
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if (!bio) {
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err = -ENOMEM;
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goto free_bios;
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}
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bio->bi_end_io = scsi_bi_endio;
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}
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if (bio_add_pc_page(q, bio, page, bytes, off) !=
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bytes) {
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bio_put(bio);
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err = -EINVAL;
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goto free_bios;
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}
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if (bio->bi_vcnt >= nr_vecs) {
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err = scsi_merge_bio(rq, bio);
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if (err) {
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bio_endio(bio, 0);
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goto free_bios;
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}
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bio = NULL;
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}
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page++;
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len -= bytes;
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data_len -=bytes;
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off = 0;
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}
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}
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rq->buffer = rq->data = NULL;
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rq->data_len = bufflen;
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return 0;
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free_bios:
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while ((bio = rq->bio) != NULL) {
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rq->bio = bio->bi_next;
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/*
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* call endio instead of bio_put incase it was bounced
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*/
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bio_endio(bio, 0);
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}
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return err;
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}
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/**
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* scsi_execute_async - insert request
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* @sdev: scsi device
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* @cmd: scsi command
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* @cmd_len: length of scsi cdb
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* @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE
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* @buffer: data buffer (this can be a kernel buffer or scatterlist)
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* @bufflen: len of buffer
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* @use_sg: if buffer is a scatterlist this is the number of elements
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* @timeout: request timeout in seconds
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* @retries: number of times to retry request
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* @privdata: data passed to done()
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* @done: callback function when done
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* @gfp: memory allocation flags
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*/
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int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
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int cmd_len, int data_direction, void *buffer, unsigned bufflen,
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int use_sg, int timeout, int retries, void *privdata,
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void (*done)(void *, char *, int, int), gfp_t gfp)
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{
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struct request *req;
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struct scsi_io_context *sioc;
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int err = 0;
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int write = (data_direction == DMA_TO_DEVICE);
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sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp);
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if (!sioc)
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return DRIVER_ERROR << 24;
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req = blk_get_request(sdev->request_queue, write, gfp);
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if (!req)
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goto free_sense;
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req->cmd_type = REQ_TYPE_BLOCK_PC;
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req->cmd_flags |= REQ_QUIET;
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if (use_sg)
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err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp);
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else if (bufflen)
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err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp);
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if (err)
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goto free_req;
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req->cmd_len = cmd_len;
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memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
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memcpy(req->cmd, cmd, req->cmd_len);
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req->sense = sioc->sense;
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req->sense_len = 0;
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req->timeout = timeout;
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req->retries = retries;
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req->end_io_data = sioc;
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sioc->data = privdata;
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sioc->done = done;
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blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async);
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return 0;
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free_req:
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blk_put_request(req);
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free_sense:
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kmem_cache_free(scsi_io_context_cache, sioc);
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return DRIVER_ERROR << 24;
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}
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EXPORT_SYMBOL_GPL(scsi_execute_async);
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|
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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 = COMMAND_SIZE(cmd->cmnd[0]);
|
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}
|
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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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unsigned long flags;
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spin_lock_irqsave(shost->host_lock, flags);
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shost->host_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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scsi_eh_wakeup(shost);
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spin_unlock(shost->host_lock);
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spin_lock(sdev->request_queue->queue_lock);
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sdev->device_busy--;
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spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
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}
|
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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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/*
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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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blk_run_queue(current_sdev->request_queue);
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|
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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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|
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spin_unlock_irqrestore(shost->host_lock, flags);
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blk_run_queue(sdev->request_queue);
|
|
spin_lock_irqsave(shost->host_lock, flags);
|
|
|
|
scsi_device_put(sdev);
|
|
}
|
|
out:
|
|
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;
|
|
struct Scsi_Host *shost = sdev->host;
|
|
unsigned long flags;
|
|
|
|
if (scsi_target(sdev)->single_lun)
|
|
scsi_single_lun_run(sdev);
|
|
|
|
spin_lock_irqsave(shost->host_lock, flags);
|
|
while (!list_empty(&shost->starved_list) &&
|
|
!shost->host_blocked && !shost->host_self_blocked &&
|
|
!((shost->can_queue > 0) &&
|
|
(shost->host_busy >= shost->can_queue))) {
|
|
/*
|
|
* As long as shost is accepting commands and we have
|
|
* starved queues, call blk_run_queue. scsi_request_fn
|
|
* drops the queue_lock and can add us back to the
|
|
* starved_list.
|
|
*
|
|
* host_lock protects the starved_list and starved_entry.
|
|
* scsi_request_fn must get the host_lock before checking
|
|
* or modifying starved_list or starved_entry.
|
|
*/
|
|
sdev = list_entry(shost->starved_list.next,
|
|
struct scsi_device, starved_entry);
|
|
list_del_init(&sdev->starved_entry);
|
|
spin_unlock_irqrestore(shost->host_lock, flags);
|
|
|
|
|
|
if (test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) &&
|
|
!test_and_set_bit(QUEUE_FLAG_REENTER,
|
|
&sdev->request_queue->queue_flags)) {
|
|
blk_run_queue(sdev->request_queue);
|
|
clear_bit(QUEUE_FLAG_REENTER,
|
|
&sdev->request_queue->queue_flags);
|
|
} else
|
|
blk_run_queue(sdev->request_queue);
|
|
|
|
spin_lock_irqsave(shost->host_lock, flags);
|
|
if (unlikely(!list_empty(&sdev->starved_entry)))
|
|
/*
|
|
* sdev lost a race, and was put back on the
|
|
* starved list. This is unlikely but without this
|
|
* in theory we could loop forever.
|
|
*/
|
|
break;
|
|
}
|
|
spin_unlock_irqrestore(shost->host_lock, flags);
|
|
|
|
blk_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 request *req = cmd->request;
|
|
unsigned long flags;
|
|
|
|
scsi_unprep_request(req);
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
blk_requeue_request(q, req);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
|
|
scsi_run_queue(q);
|
|
}
|
|
|
|
void scsi_next_command(struct scsi_cmnd *cmd)
|
|
{
|
|
struct scsi_device *sdev = cmd->device;
|
|
struct request_queue *q = sdev->request_queue;
|
|
|
|
/* need to hold a reference on the device before we let go of the cmd */
|
|
get_device(&sdev->sdev_gendev);
|
|
|
|
scsi_put_command(cmd);
|
|
scsi_run_queue(q);
|
|
|
|
/* ok to remove device now */
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_end_request()
|
|
*
|
|
* Purpose: Post-processing of completed commands (usually invoked at end
|
|
* of upper level post-processing and scsi_io_completion).
|
|
*
|
|
* Arguments: cmd - command that is complete.
|
|
* error - 0 if I/O indicates success, < 0 for I/O error.
|
|
* bytes - number of bytes of completed I/O
|
|
* requeue - indicates whether we should requeue leftovers.
|
|
*
|
|
* Lock status: Assumed that lock is not held upon entry.
|
|
*
|
|
* Returns: cmd if requeue required, NULL otherwise.
|
|
*
|
|
* Notes: This is called for block device requests in order to
|
|
* mark some number of sectors as complete.
|
|
*
|
|
* We are guaranteeing that the request queue will be goosed
|
|
* at some point during this call.
|
|
* Notes: If cmd was requeued, upon return it will be a stale pointer.
|
|
*/
|
|
static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
|
|
int bytes, int requeue)
|
|
{
|
|
struct request_queue *q = cmd->device->request_queue;
|
|
struct request *req = cmd->request;
|
|
|
|
/*
|
|
* If there are blocks left over at the end, set up the command
|
|
* to queue the remainder of them.
|
|
*/
|
|
if (blk_end_request(req, error, bytes)) {
|
|
int leftover = (req->hard_nr_sectors << 9);
|
|
|
|
if (blk_pc_request(req))
|
|
leftover = req->data_len;
|
|
|
|
/* kill remainder if no retrys */
|
|
if (error && blk_noretry_request(req))
|
|
blk_end_request(req, error, leftover);
|
|
else {
|
|
if (requeue) {
|
|
/*
|
|
* Bleah. Leftovers again. Stick the
|
|
* leftovers in the front of the
|
|
* queue, and goose the queue again.
|
|
*/
|
|
scsi_requeue_command(q, cmd);
|
|
cmd = NULL;
|
|
}
|
|
return cmd;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This will goose the queue request function at the end, so we don't
|
|
* need to worry about launching another command.
|
|
*/
|
|
scsi_next_command(cmd);
|
|
return NULL;
|
|
}
|
|
|
|
static inline unsigned int scsi_sgtable_index(unsigned short nents)
|
|
{
|
|
unsigned int index;
|
|
|
|
BUG_ON(nents > SCSI_MAX_SG_SEGMENTS);
|
|
|
|
if (nents <= 8)
|
|
index = 0;
|
|
else
|
|
index = get_count_order(nents) - 3;
|
|
|
|
return index;
|
|
}
|
|
|
|
static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents)
|
|
{
|
|
struct scsi_host_sg_pool *sgp;
|
|
|
|
sgp = scsi_sg_pools + scsi_sgtable_index(nents);
|
|
mempool_free(sgl, sgp->pool);
|
|
}
|
|
|
|
static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
|
|
{
|
|
struct scsi_host_sg_pool *sgp;
|
|
|
|
sgp = scsi_sg_pools + scsi_sgtable_index(nents);
|
|
return mempool_alloc(sgp->pool, gfp_mask);
|
|
}
|
|
|
|
static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents,
|
|
gfp_t gfp_mask)
|
|
{
|
|
int ret;
|
|
|
|
BUG_ON(!nents);
|
|
|
|
ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS,
|
|
gfp_mask, scsi_sg_alloc);
|
|
if (unlikely(ret))
|
|
__sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS,
|
|
scsi_sg_free);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
|
|
{
|
|
__sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
|
|
}
|
|
|
|
/*
|
|
* Function: scsi_release_buffers()
|
|
*
|
|
* Purpose: Completion processing for block device I/O requests.
|
|
*
|
|
* 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, and potentially any bounce
|
|
* buffers.
|
|
*/
|
|
void scsi_release_buffers(struct scsi_cmnd *cmd)
|
|
{
|
|
if (cmd->sdb.table.nents)
|
|
scsi_free_sgtable(&cmd->sdb);
|
|
|
|
memset(&cmd->sdb, 0, sizeof(cmd->sdb));
|
|
|
|
if (scsi_bidi_cmnd(cmd)) {
|
|
struct scsi_data_buffer *bidi_sdb =
|
|
cmd->request->next_rq->special;
|
|
scsi_free_sgtable(bidi_sdb);
|
|
kmem_cache_free(scsi_bidi_sdb_cache, bidi_sdb);
|
|
cmd->request->next_rq->special = NULL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(scsi_release_buffers);
|
|
|
|
/*
|
|
* Bidi commands Must be complete as a whole, both sides at once.
|
|
* If part of the bytes were written and lld returned
|
|
* scsi_in()->resid and/or scsi_out()->resid this information will be left
|
|
* in req->data_len and req->next_rq->data_len. The upper-layer driver can
|
|
* decide what to do with this information.
|
|
*/
|
|
void scsi_end_bidi_request(struct scsi_cmnd *cmd)
|
|
{
|
|
struct request *req = cmd->request;
|
|
unsigned int dlen = req->data_len;
|
|
unsigned int next_dlen = req->next_rq->data_len;
|
|
|
|
req->data_len = scsi_out(cmd)->resid;
|
|
req->next_rq->data_len = scsi_in(cmd)->resid;
|
|
|
|
/* The req and req->next_rq have not been completed */
|
|
BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen));
|
|
|
|
scsi_release_buffers(cmd);
|
|
|
|
/*
|
|
* This will goose the queue request function at the end, so we don't
|
|
* need to worry about launching another command.
|
|
*/
|
|
scsi_next_command(cmd);
|
|
}
|
|
|
|
/*
|
|
* 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: This function is matched in terms of capabilities to
|
|
* the function that created the scatter-gather list.
|
|
* In other words, if there are no bounce buffers
|
|
* (the normal case for most drivers), we don't need
|
|
* the logic to deal with cleaning up afterwards.
|
|
*
|
|
* We must do one of several things here:
|
|
*
|
|
* a) Call scsi_end_request. This 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
|
|
* scsi_end_request will directly goose the queue.
|
|
*
|
|
* b) We can just use scsi_requeue_command() here. This would
|
|
* be used if we just wanted to retry, for example.
|
|
*/
|
|
void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
|
|
{
|
|
int result = cmd->result;
|
|
int this_count = scsi_bufflen(cmd);
|
|
struct request_queue *q = cmd->device->request_queue;
|
|
struct request *req = cmd->request;
|
|
int clear_errors = 1;
|
|
struct scsi_sense_hdr sshdr;
|
|
int sense_valid = 0;
|
|
int sense_deferred = 0;
|
|
|
|
if (result) {
|
|
sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
|
|
if (sense_valid)
|
|
sense_deferred = scsi_sense_is_deferred(&sshdr);
|
|
}
|
|
|
|
if (blk_pc_request(req)) { /* SG_IO ioctl from block level */
|
|
req->errors = result;
|
|
if (result) {
|
|
clear_errors = 0;
|
|
if (sense_valid && req->sense) {
|
|
/*
|
|
* SG_IO wants current and deferred errors
|
|
*/
|
|
int len = 8 + cmd->sense_buffer[7];
|
|
|
|
if (len > SCSI_SENSE_BUFFERSIZE)
|
|
len = SCSI_SENSE_BUFFERSIZE;
|
|
memcpy(req->sense, cmd->sense_buffer, len);
|
|
req->sense_len = len;
|
|
}
|
|
}
|
|
if (scsi_bidi_cmnd(cmd)) {
|
|
/* will also release_buffers */
|
|
scsi_end_bidi_request(cmd);
|
|
return;
|
|
}
|
|
req->data_len = scsi_get_resid(cmd);
|
|
}
|
|
|
|
BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */
|
|
scsi_release_buffers(cmd);
|
|
|
|
/*
|
|
* Next deal with any sectors which we were able to correctly
|
|
* handle.
|
|
*/
|
|
SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, "
|
|
"%d bytes done.\n",
|
|
req->nr_sectors, good_bytes));
|
|
|
|
if (clear_errors)
|
|
req->errors = 0;
|
|
|
|
/* A number of bytes were successfully read. If there
|
|
* are leftovers and there is some kind of error
|
|
* (result != 0), retry the rest.
|
|
*/
|
|
if (scsi_end_request(cmd, 0, good_bytes, result == 0) == NULL)
|
|
return;
|
|
|
|
/* good_bytes = 0, or (inclusive) there were leftovers and
|
|
* result = 0, so scsi_end_request couldn't retry.
|
|
*/
|
|
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;
|
|
scsi_end_request(cmd, -EIO, this_count, 1);
|
|
return;
|
|
} else {
|
|
/* Must have been a power glitch, or a
|
|
* bus reset. Could not have been a
|
|
* media change, so we just retry the
|
|
* request and see what happens.
|
|
*/
|
|
scsi_requeue_command(q, cmd);
|
|
return;
|
|
}
|
|
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)) {
|
|
cmd->device->use_10_for_rw = 0;
|
|
/* This will cause a retry with a
|
|
* 6-byte command.
|
|
*/
|
|
scsi_requeue_command(q, cmd);
|
|
return;
|
|
} else {
|
|
scsi_end_request(cmd, -EIO, this_count, 1);
|
|
return;
|
|
}
|
|
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 */
|
|
scsi_requeue_command(q, cmd);
|
|
return;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
if (!(req->cmd_flags & REQ_QUIET))
|
|
scsi_cmd_print_sense_hdr(cmd,
|
|
"Device not ready",
|
|
&sshdr);
|
|
|
|
scsi_end_request(cmd, -EIO, this_count, 1);
|
|
return;
|
|
case VOLUME_OVERFLOW:
|
|
if (!(req->cmd_flags & REQ_QUIET)) {
|
|
scmd_printk(KERN_INFO, cmd,
|
|
"Volume overflow, CDB: ");
|
|
__scsi_print_command(cmd->cmnd);
|
|
scsi_print_sense("", cmd);
|
|
}
|
|
/* See SSC3rXX or current. */
|
|
scsi_end_request(cmd, -EIO, this_count, 1);
|
|
return;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
if (host_byte(result) == DID_RESET) {
|
|
/* Third party bus reset or reset for error recovery
|
|
* reasons. Just retry the request and see what
|
|
* happens.
|
|
*/
|
|
scsi_requeue_command(q, cmd);
|
|
return;
|
|
}
|
|
if (result) {
|
|
if (!(req->cmd_flags & REQ_QUIET)) {
|
|
scsi_print_result(cmd);
|
|
if (driver_byte(result) & DRIVER_SENSE)
|
|
scsi_print_sense("", cmd);
|
|
}
|
|
}
|
|
scsi_end_request(cmd, -EIO, this_count, !result);
|
|
}
|
|
|
|
static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
|
|
gfp_t gfp_mask)
|
|
{
|
|
int count;
|
|
|
|
/*
|
|
* If sg table allocation fails, requeue request later.
|
|
*/
|
|
if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments,
|
|
gfp_mask))) {
|
|
return BLKPREP_DEFER;
|
|
}
|
|
|
|
req->buffer = NULL;
|
|
if (blk_pc_request(req))
|
|
sdb->length = req->data_len;
|
|
else
|
|
sdb->length = req->nr_sectors << 9;
|
|
|
|
/*
|
|
* 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;
|
|
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, gfp_t gfp_mask)
|
|
{
|
|
int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask);
|
|
if (error)
|
|
goto err_exit;
|
|
|
|
if (blk_bidi_rq(cmd->request)) {
|
|
struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc(
|
|
scsi_bidi_sdb_cache, GFP_ATOMIC);
|
|
if (!bidi_sdb) {
|
|
error = BLKPREP_DEFER;
|
|
goto err_exit;
|
|
}
|
|
|
|
cmd->request->next_rq->special = bidi_sdb;
|
|
error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb,
|
|
GFP_ATOMIC);
|
|
if (error)
|
|
goto err_exit;
|
|
}
|
|
|
|
return BLKPREP_OK ;
|
|
|
|
err_exit:
|
|
scsi_release_buffers(cmd);
|
|
if (error == BLKPREP_KILL)
|
|
scsi_put_command(cmd);
|
|
else /* BLKPREP_DEFER */
|
|
scsi_unprep_request(cmd->request);
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL(scsi_init_io);
|
|
|
|
static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
|
|
struct request *req)
|
|
{
|
|
struct scsi_cmnd *cmd;
|
|
|
|
if (!req->special) {
|
|
cmd = scsi_get_command(sdev, GFP_ATOMIC);
|
|
if (unlikely(!cmd))
|
|
return NULL;
|
|
req->special = cmd;
|
|
} else {
|
|
cmd = req->special;
|
|
}
|
|
|
|
/* pull a tag out of the request if we have one */
|
|
cmd->tag = req->tag;
|
|
cmd->request = req;
|
|
|
|
return cmd;
|
|
}
|
|
|
|
int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
|
|
{
|
|
struct scsi_cmnd *cmd;
|
|
int ret = scsi_prep_state_check(sdev, req);
|
|
|
|
if (ret != BLKPREP_OK)
|
|
return ret;
|
|
|
|
cmd = scsi_get_cmd_from_req(sdev, req);
|
|
if (unlikely(!cmd))
|
|
return BLKPREP_DEFER;
|
|
|
|
/*
|
|
* BLOCK_PC 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;
|
|
|
|
BUG_ON(!req->nr_phys_segments);
|
|
|
|
ret = scsi_init_io(cmd, GFP_ATOMIC);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
} else {
|
|
BUG_ON(req->data_len);
|
|
BUG_ON(req->data);
|
|
|
|
memset(&cmd->sdb, 0, sizeof(cmd->sdb));
|
|
req->buffer = NULL;
|
|
}
|
|
|
|
BUILD_BUG_ON(sizeof(req->cmd) > sizeof(cmd->cmnd));
|
|
memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd));
|
|
cmd->cmd_len = req->cmd_len;
|
|
if (!req->data_len)
|
|
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;
|
|
|
|
cmd->transfersize = req->data_len;
|
|
cmd->allowed = req->retries;
|
|
cmd->timeout_per_command = req->timeout;
|
|
return BLKPREP_OK;
|
|
}
|
|
EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
|
|
|
|
/*
|
|
* Setup a REQ_TYPE_FS command. These are simple read/write request
|
|
* from filesystems that still need to be translated to SCSI CDBs from
|
|
* the ULD.
|
|
*/
|
|
int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
|
|
{
|
|
struct scsi_cmnd *cmd;
|
|
int ret = scsi_prep_state_check(sdev, req);
|
|
|
|
if (ret != BLKPREP_OK)
|
|
return ret;
|
|
/*
|
|
* Filesystem requests must transfer data.
|
|
*/
|
|
BUG_ON(!req->nr_phys_segments);
|
|
|
|
cmd = scsi_get_cmd_from_req(sdev, req);
|
|
if (unlikely(!cmd))
|
|
return BLKPREP_DEFER;
|
|
|
|
return scsi_init_io(cmd, GFP_ATOMIC);
|
|
}
|
|
EXPORT_SYMBOL(scsi_setup_fs_cmnd);
|
|
|
|
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:
|
|
/*
|
|
* 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_QUIESCE:
|
|
case SDEV_BLOCK:
|
|
/*
|
|
* If the devices is blocked we defer normal commands.
|
|
*/
|
|
if (!(req->cmd_flags & REQ_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->cmd_flags & REQ_PREEMPT))
|
|
ret = BLKPREP_KILL;
|
|
break;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(scsi_prep_state_check);
|
|
|
|
int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
|
|
{
|
|
struct scsi_device *sdev = q->queuedata;
|
|
|
|
switch (ret) {
|
|
case BLKPREP_KILL:
|
|
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);
|
|
req->special = NULL;
|
|
}
|
|
break;
|
|
case BLKPREP_DEFER:
|
|
/*
|
|
* If we defer, the elv_next_request() returns NULL, but the
|
|
* queue must be restarted, so we plug here if no returning
|
|
* command will automatically do that.
|
|
*/
|
|
if (sdev->device_busy == 0)
|
|
blk_plug_device(q);
|
|
break;
|
|
default:
|
|
req->cmd_flags |= REQ_DONTPREP;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(scsi_prep_return);
|
|
|
|
int scsi_prep_fn(struct request_queue *q, struct request *req)
|
|
{
|
|
struct scsi_device *sdev = q->queuedata;
|
|
int ret = BLKPREP_KILL;
|
|
|
|
if (req->cmd_type == REQ_TYPE_BLOCK_PC)
|
|
ret = scsi_setup_blk_pc_cmnd(sdev, req);
|
|
return scsi_prep_return(q, req, ret);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
if (sdev->device_busy >= sdev->queue_depth)
|
|
return 0;
|
|
if (sdev->device_busy == 0 && sdev->device_blocked) {
|
|
/*
|
|
* unblock after device_blocked iterates to zero
|
|
*/
|
|
if (--sdev->device_blocked == 0) {
|
|
SCSI_LOG_MLQUEUE(3,
|
|
sdev_printk(KERN_INFO, sdev,
|
|
"unblocking device at zero depth\n"));
|
|
} else {
|
|
blk_plug_device(q);
|
|
return 0;
|
|
}
|
|
}
|
|
if (sdev->device_blocked)
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* Called with host_lock held.
|
|
*/
|
|
static inline int scsi_host_queue_ready(struct request_queue *q,
|
|
struct Scsi_Host *shost,
|
|
struct scsi_device *sdev)
|
|
{
|
|
if (scsi_host_in_recovery(shost))
|
|
return 0;
|
|
if (shost->host_busy == 0 && shost->host_blocked) {
|
|
/*
|
|
* unblock after host_blocked iterates to zero
|
|
*/
|
|
if (--shost->host_blocked == 0) {
|
|
SCSI_LOG_MLQUEUE(3,
|
|
printk("scsi%d unblocking host at zero depth\n",
|
|
shost->host_no));
|
|
} else {
|
|
blk_plug_device(q);
|
|
return 0;
|
|
}
|
|
}
|
|
if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) ||
|
|
shost->host_blocked || shost->host_self_blocked) {
|
|
if (list_empty(&sdev->starved_entry))
|
|
list_add_tail(&sdev->starved_entry, &shost->starved_list);
|
|
return 0;
|
|
}
|
|
|
|
/* We're OK to process the command, so we can't be starved */
|
|
if (!list_empty(&sdev->starved_entry))
|
|
list_del_init(&sdev->starved_entry);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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 = cmd->device;
|
|
struct Scsi_Host *shost = sdev->host;
|
|
|
|
blkdev_dequeue_request(req);
|
|
|
|
if (unlikely(cmd == NULL)) {
|
|
printk(KERN_CRIT "impossible request in %s.\n",
|
|
__FUNCTION__);
|
|
BUG();
|
|
}
|
|
|
|
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.
|
|
*/
|
|
sdev->device_busy++;
|
|
spin_unlock(sdev->request_queue->queue_lock);
|
|
spin_lock(shost->host_lock);
|
|
shost->host_busy++;
|
|
spin_unlock(shost->host_lock);
|
|
spin_lock(sdev->request_queue->queue_lock);
|
|
|
|
__scsi_done(cmd);
|
|
}
|
|
|
|
static void scsi_softirq_done(struct request *rq)
|
|
{
|
|
struct scsi_cmnd *cmd = rq->completion_data;
|
|
unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command;
|
|
int disposition;
|
|
|
|
INIT_LIST_HEAD(&cmd->eh_entry);
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct scsi_device *sdev = q->queuedata;
|
|
struct Scsi_Host *shost;
|
|
struct scsi_cmnd *cmd;
|
|
struct request *req;
|
|
|
|
if (!sdev) {
|
|
printk("scsi: killing requests for dead queue\n");
|
|
while ((req = elv_next_request(q)) != NULL)
|
|
scsi_kill_request(req, q);
|
|
return;
|
|
}
|
|
|
|
if(!get_device(&sdev->sdev_gendev))
|
|
/* We must be tearing the block queue down already */
|
|
return;
|
|
|
|
/*
|
|
* 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;
|
|
while (!blk_queue_plugged(q)) {
|
|
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 = elv_next_request(q);
|
|
if (!req || !scsi_dev_queue_ready(q, sdev))
|
|
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;
|
|
}
|
|
|
|
|
|
/*
|
|
* Remove the request from the request list.
|
|
*/
|
|
if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
|
|
blkdev_dequeue_request(req);
|
|
sdev->device_busy++;
|
|
|
|
spin_unlock(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",
|
|
__FUNCTION__);
|
|
blk_dump_rq_flags(req, "foo");
|
|
BUG();
|
|
}
|
|
spin_lock(shost->host_lock);
|
|
|
|
if (!scsi_host_queue_ready(q, shost, sdev))
|
|
goto not_ready;
|
|
if (scsi_target(sdev)->single_lun) {
|
|
if (scsi_target(sdev)->starget_sdev_user &&
|
|
scsi_target(sdev)->starget_sdev_user != sdev)
|
|
goto not_ready;
|
|
scsi_target(sdev)->starget_sdev_user = sdev;
|
|
}
|
|
shost->host_busy++;
|
|
|
|
/*
|
|
* XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will
|
|
* take the lock again.
|
|
*/
|
|
spin_unlock_irq(shost->host_lock);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
rtn = scsi_dispatch_cmd(cmd);
|
|
spin_lock_irq(q->queue_lock);
|
|
if(rtn) {
|
|
/* we're refusing the command; because of
|
|
* the way locks get dropped, we need to
|
|
* check here if plugging is required */
|
|
if(sdev->device_busy == 0)
|
|
blk_plug_device(q);
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
goto out;
|
|
|
|
not_ready:
|
|
spin_unlock_irq(shost->host_lock);
|
|
|
|
/*
|
|
* 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);
|
|
sdev->device_busy--;
|
|
if(sdev->device_busy == 0)
|
|
blk_plug_device(q);
|
|
out:
|
|
/* must be careful here...if we trigger the ->remove() function
|
|
* we cannot be holding the q lock */
|
|
spin_unlock_irq(q->queue_lock);
|
|
put_device(&sdev->sdev_gendev);
|
|
spin_lock_irq(q->queue_lock);
|
|
}
|
|
|
|
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 = *host_dev->dma_mask;
|
|
|
|
return bounce_limit;
|
|
}
|
|
EXPORT_SYMBOL(scsi_calculate_bounce_limit);
|
|
|
|
struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
|
|
request_fn_proc *request_fn)
|
|
{
|
|
struct request_queue *q;
|
|
|
|
q = blk_init_queue(request_fn, NULL);
|
|
if (!q)
|
|
return NULL;
|
|
|
|
/*
|
|
* this limit is imposed by hardware restrictions
|
|
*/
|
|
blk_queue_max_hw_segments(q, shost->sg_tablesize);
|
|
blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS);
|
|
|
|
blk_queue_max_sectors(q, shost->max_sectors);
|
|
blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
|
|
blk_queue_segment_boundary(q, shost->dma_boundary);
|
|
|
|
if (!shost->use_clustering)
|
|
clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
return q;
|
|
}
|
|
EXPORT_SYMBOL(__scsi_alloc_queue);
|
|
|
|
struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
|
|
{
|
|
struct request_queue *q;
|
|
|
|
q = __scsi_alloc_queue(sdev->host, scsi_request_fn);
|
|
if (!q)
|
|
return NULL;
|
|
|
|
blk_queue_prep_rq(q, scsi_prep_fn);
|
|
blk_queue_softirq_done(q, scsi_softirq_done);
|
|
return q;
|
|
}
|
|
|
|
void scsi_free_queue(struct request_queue *q)
|
|
{
|
|
blk_cleanup_queue(q);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
int i;
|
|
|
|
scsi_io_context_cache = kmem_cache_create("scsi_io_context",
|
|
sizeof(struct scsi_io_context),
|
|
0, 0, NULL);
|
|
if (!scsi_io_context_cache) {
|
|
printk(KERN_ERR "SCSI: can't init scsi io context cache\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
scsi_bidi_sdb_cache = kmem_cache_create("scsi_bidi_sdb",
|
|
sizeof(struct scsi_data_buffer),
|
|
0, 0, NULL);
|
|
if (!scsi_bidi_sdb_cache) {
|
|
printk(KERN_ERR "SCSI: can't init scsi bidi sdb cache\n");
|
|
goto cleanup_io_context;
|
|
}
|
|
|
|
for (i = 0; i < SG_MEMPOOL_NR; i++) {
|
|
struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
|
|
int size = sgp->size * sizeof(struct scatterlist);
|
|
|
|
sgp->slab = kmem_cache_create(sgp->name, size, 0,
|
|
SLAB_HWCACHE_ALIGN, NULL);
|
|
if (!sgp->slab) {
|
|
printk(KERN_ERR "SCSI: can't init sg slab %s\n",
|
|
sgp->name);
|
|
goto cleanup_bidi_sdb;
|
|
}
|
|
|
|
sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE,
|
|
sgp->slab);
|
|
if (!sgp->pool) {
|
|
printk(KERN_ERR "SCSI: can't init sg mempool %s\n",
|
|
sgp->name);
|
|
goto cleanup_bidi_sdb;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
cleanup_bidi_sdb:
|
|
for (i = 0; i < SG_MEMPOOL_NR; i++) {
|
|
struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
|
|
if (sgp->pool)
|
|
mempool_destroy(sgp->pool);
|
|
if (sgp->slab)
|
|
kmem_cache_destroy(sgp->slab);
|
|
}
|
|
kmem_cache_destroy(scsi_bidi_sdb_cache);
|
|
cleanup_io_context:
|
|
kmem_cache_destroy(scsi_io_context_cache);
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
void scsi_exit_queue(void)
|
|
{
|
|
int i;
|
|
|
|
kmem_cache_destroy(scsi_io_context_cache);
|
|
kmem_cache_destroy(scsi_bidi_sdb_cache);
|
|
|
|
for (i = 0; i < SG_MEMPOOL_NR; i++) {
|
|
struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
|
|
mempool_destroy(sgp->pool);
|
|
kmem_cache_destroy(sgp->slab);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
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;
|
|
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);
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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, a return of NOT_READY or UNIT_ATTENTION is
|
|
* translated to success, with the ->changed flag updated.
|
|
**/
|
|
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);
|
|
} while ((driver_byte(result) & DRIVER_SENSE) &&
|
|
sshdr && sshdr->sense_key == UNIT_ATTENTION &&
|
|
--retries);
|
|
|
|
if (!sshdr)
|
|
/* could not allocate sense buffer, so can't process it */
|
|
return result;
|
|
|
|
if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) {
|
|
|
|
if ((scsi_sense_valid(sshdr)) &&
|
|
((sshdr->sense_key == UNIT_ATTENTION) ||
|
|
(sshdr->sense_key == NOT_READY))) {
|
|
sdev->changed = 1;
|
|
result = 0;
|
|
}
|
|
}
|
|
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:
|
|
/* There are no legal states that come back to
|
|
* created. This is the manually initialised start
|
|
* state */
|
|
goto illegal;
|
|
|
|
case SDEV_RUNNING:
|
|
switch (oldstate) {
|
|
case SDEV_CREATED:
|
|
case SDEV_OFFLINE:
|
|
case SDEV_QUIESCE:
|
|
case SDEV_BLOCK:
|
|
break;
|
|
default:
|
|
goto illegal;
|
|
}
|
|
break;
|
|
|
|
case SDEV_QUIESCE:
|
|
switch (oldstate) {
|
|
case SDEV_RUNNING:
|
|
case SDEV_OFFLINE:
|
|
break;
|
|
default:
|
|
goto illegal;
|
|
}
|
|
break;
|
|
|
|
case SDEV_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_CREATED:
|
|
case SDEV_RUNNING:
|
|
break;
|
|
default:
|
|
goto illegal;
|
|
}
|
|
break;
|
|
|
|
case SDEV_CANCEL:
|
|
switch (oldstate) {
|
|
case SDEV_CREATED:
|
|
case SDEV_RUNNING:
|
|
case SDEV_QUIESCE:
|
|
case SDEV_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_CANCEL:
|
|
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\n",
|
|
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;
|
|
|
|
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;
|
|
LIST_HEAD(event_list);
|
|
|
|
sdev = container_of(work, struct scsi_device, event_work);
|
|
|
|
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 (!test_bit(evt->evt_type, sdev->supported_events)) {
|
|
kfree(evt);
|
|
return;
|
|
}
|
|
|
|
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:
|
|
default:
|
|
/* do nothing */
|
|
break;
|
|
}
|
|
|
|
return evt;
|
|
}
|
|
EXPORT_SYMBOL_GPL(sdev_evt_alloc);
|
|
|
|
/**
|
|
* sdev_evt_send_simple - send asserted event to uevent thread
|
|
* @sdev: scsi_device event occurred on
|
|
* @evt_type: type of event to send
|
|
* @gfpflags: GFP flags for allocation
|
|
*
|
|
* Assert scsi device event asynchronously, given an event type.
|
|
*/
|
|
void sdev_evt_send_simple(struct scsi_device *sdev,
|
|
enum scsi_device_event evt_type, gfp_t gfpflags)
|
|
{
|
|
struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
|
|
if (!evt) {
|
|
sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
|
|
evt_type);
|
|
return;
|
|
}
|
|
|
|
sdev_evt_send(sdev, evt);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
|
|
|
|
/**
|
|
* scsi_device_quiesce - Block 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 (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)
|
|
{
|
|
if(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. Called from interrupt
|
|
* or normal process context.
|
|
*
|
|
* 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.
|
|
* This routine assumes the host_lock is held on entry.
|
|
*/
|
|
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)
|
|
return err;
|
|
|
|
/*
|
|
* The device has transitioned to SDEV_BLOCK. Stop the
|
|
* block layer from calling the midlayer with this device's
|
|
* request queue.
|
|
*/
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
blk_stop_queue(q);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(scsi_internal_device_block);
|
|
|
|
/**
|
|
* scsi_internal_device_unblock - resume a device after a block request
|
|
* @sdev: device to resume
|
|
*
|
|
* 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
|
|
* (which must be a legal transition) allowing the midlayer to
|
|
* goose the queue for this device. This routine assumes the
|
|
* host_lock is held upon entry.
|
|
*/
|
|
int
|
|
scsi_internal_device_unblock(struct scsi_device *sdev)
|
|
{
|
|
struct request_queue *q = sdev->request_queue;
|
|
int err;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Try to transition the scsi device to SDEV_RUNNING
|
|
* and goose the device queue if successful.
|
|
*/
|
|
err = scsi_device_set_state(sdev, SDEV_RUNNING);
|
|
if (err)
|
|
return err;
|
|
|
|
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);
|
|
}
|
|
|
|
static int
|
|
target_unblock(struct device *dev, void *data)
|
|
{
|
|
if (scsi_is_target_device(dev))
|
|
starget_for_each_device(to_scsi_target(dev), NULL,
|
|
device_unblock);
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
scsi_target_unblock(struct device *dev)
|
|
{
|
|
if (scsi_is_target_device(dev))
|
|
starget_for_each_device(to_scsi_target(dev), NULL,
|
|
device_unblock);
|
|
else
|
|
device_for_each_child(dev, NULL, 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",
|
|
__FUNCTION__, 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, KM_BIO_SRC_IRQ);
|
|
}
|
|
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, KM_BIO_SRC_IRQ);
|
|
}
|
|
EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
|