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[SCSI] scsi tgt: scsi target lib functionality
The core scsi target lib functions. TODO: - mv md/dm-bio-list.h to linux/bio-list.h so md and us do not have to do that weird include. - convert scsi_tgt_cmd's work struct to James's execute code. And try to kill our scsi_tgt_cmd. - add host state checking. We do refcouting so hotplug is partially supported, but we need to add state checking to make it easier on the LLD. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
FUJITA Tomonori
James Bottomley
parent
b58d91547f
commit
5a55c2596f
742
drivers/scsi/scsi_tgt_lib.c
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742
drivers/scsi/scsi_tgt_lib.c
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@ -0,0 +1,742 @@
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/*
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* SCSI target lib functions
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*
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* Copyright (C) 2005 Mike Christie <michaelc@cs.wisc.edu>
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* Copyright (C) 2005 FUJITA Tomonori <tomof@acm.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#include <linux/blkdev.h>
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#include <linux/hash.h>
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#include <linux/module.h>
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#include <linux/pagemap.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_device.h>
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#include <scsi/scsi_host.h>
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#include <scsi/scsi_tgt.h>
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#include <../drivers/md/dm-bio-list.h>
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#include "scsi_tgt_priv.h"
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static struct workqueue_struct *scsi_tgtd;
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static kmem_cache_t *scsi_tgt_cmd_cache;
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/*
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* TODO: this struct will be killed when the block layer supports large bios
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* and James's work struct code is in
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*/
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struct scsi_tgt_cmd {
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/* TODO replace work with James b's code */
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struct work_struct work;
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/* TODO replace the lists with a large bio */
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struct bio_list xfer_done_list;
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struct bio_list xfer_list;
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struct list_head hash_list;
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struct request *rq;
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u64 tag;
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void *buffer;
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unsigned bufflen;
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};
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#define TGT_HASH_ORDER 4
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#define cmd_hashfn(tag) hash_long((unsigned long) (tag), TGT_HASH_ORDER)
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struct scsi_tgt_queuedata {
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struct Scsi_Host *shost;
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struct list_head cmd_hash[1 << TGT_HASH_ORDER];
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spinlock_t cmd_hash_lock;
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};
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/*
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* Function: scsi_host_get_command()
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*
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* Purpose: Allocate and setup a scsi command block and blk request
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*
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* Arguments: shost - scsi host
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* data_dir - dma data dir
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* gfp_mask- allocator flags
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*
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* Returns: The allocated scsi command structure.
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*
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* This should be called by target LLDs to get a command.
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*/
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struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *shost,
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enum dma_data_direction data_dir,
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gfp_t gfp_mask)
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{
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int write = (data_dir == DMA_TO_DEVICE);
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struct request *rq;
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struct scsi_cmnd *cmd;
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struct scsi_tgt_cmd *tcmd;
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/* Bail if we can't get a reference to the device */
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if (!get_device(&shost->shost_gendev))
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return NULL;
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tcmd = kmem_cache_alloc(scsi_tgt_cmd_cache, GFP_ATOMIC);
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if (!tcmd)
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goto put_dev;
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rq = blk_get_request(shost->uspace_req_q, write, gfp_mask);
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if (!rq)
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goto free_tcmd;
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cmd = __scsi_get_command(shost, gfp_mask);
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if (!cmd)
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goto release_rq;
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memset(cmd, 0, sizeof(*cmd));
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cmd->sc_data_direction = data_dir;
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cmd->jiffies_at_alloc = jiffies;
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cmd->request = rq;
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rq->special = cmd;
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rq->cmd_type = REQ_TYPE_SPECIAL;
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rq->cmd_flags |= REQ_TYPE_BLOCK_PC;
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rq->end_io_data = tcmd;
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bio_list_init(&tcmd->xfer_list);
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bio_list_init(&tcmd->xfer_done_list);
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tcmd->rq = rq;
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return cmd;
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release_rq:
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blk_put_request(rq);
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free_tcmd:
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kmem_cache_free(scsi_tgt_cmd_cache, tcmd);
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put_dev:
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put_device(&shost->shost_gendev);
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return NULL;
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}
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EXPORT_SYMBOL_GPL(scsi_host_get_command);
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/*
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* Function: scsi_host_put_command()
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*
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* Purpose: Free a scsi command block
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*
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* Arguments: shost - scsi host
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* cmd - command block to free
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*
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* Returns: Nothing.
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*
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* Notes: The command must not belong to any lists.
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*/
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void scsi_host_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
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{
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struct request_queue *q = shost->uspace_req_q;
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struct request *rq = cmd->request;
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struct scsi_tgt_cmd *tcmd = rq->end_io_data;
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unsigned long flags;
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kmem_cache_free(scsi_tgt_cmd_cache, tcmd);
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spin_lock_irqsave(q->queue_lock, flags);
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__blk_put_request(q, rq);
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spin_unlock_irqrestore(q->queue_lock, flags);
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__scsi_put_command(shost, cmd, &shost->shost_gendev);
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}
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EXPORT_SYMBOL_GPL(scsi_host_put_command);
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static void scsi_unmap_user_pages(struct scsi_tgt_cmd *tcmd)
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{
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struct bio *bio;
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/* must call bio_endio in case bio was bounced */
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while ((bio = bio_list_pop(&tcmd->xfer_done_list))) {
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bio_endio(bio, bio->bi_size, 0);
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bio_unmap_user(bio);
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}
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while ((bio = bio_list_pop(&tcmd->xfer_list))) {
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bio_endio(bio, bio->bi_size, 0);
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bio_unmap_user(bio);
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}
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}
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static void cmd_hashlist_del(struct scsi_cmnd *cmd)
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{
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struct request_queue *q = cmd->request->q;
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struct scsi_tgt_queuedata *qdata = q->queuedata;
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unsigned long flags;
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struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
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spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
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list_del(&tcmd->hash_list);
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spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
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}
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static void scsi_tgt_cmd_destroy(void *data)
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{
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struct scsi_cmnd *cmd = data;
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struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
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dprintk("cmd %p %d %lu\n", cmd, cmd->sc_data_direction,
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rq_data_dir(cmd->request));
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/*
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* We fix rq->cmd_flags here since when we told bio_map_user
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* to write vm for WRITE commands, blk_rq_bio_prep set
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* rq_data_dir the flags to READ.
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*/
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if (cmd->sc_data_direction == DMA_TO_DEVICE)
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cmd->request->cmd_flags |= REQ_RW;
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else
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cmd->request->cmd_flags &= ~REQ_RW;
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scsi_unmap_user_pages(tcmd);
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scsi_host_put_command(scsi_tgt_cmd_to_host(cmd), cmd);
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}
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static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd,
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u64 tag)
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{
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struct scsi_tgt_queuedata *qdata = rq->q->queuedata;
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unsigned long flags;
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struct list_head *head;
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tcmd->tag = tag;
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spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
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head = &qdata->cmd_hash[cmd_hashfn(tag)];
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list_add(&tcmd->hash_list, head);
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spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
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}
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/*
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* scsi_tgt_alloc_queue - setup queue used for message passing
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* shost: scsi host
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*
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* This should be called by the LLD after host allocation.
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* And will be released when the host is released.
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*/
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int scsi_tgt_alloc_queue(struct Scsi_Host *shost)
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{
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struct scsi_tgt_queuedata *queuedata;
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struct request_queue *q;
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int err, i;
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/*
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* Do we need to send a netlink event or should uspace
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* just respond to the hotplug event?
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*/
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q = __scsi_alloc_queue(shost, NULL);
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if (!q)
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return -ENOMEM;
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queuedata = kzalloc(sizeof(*queuedata), GFP_KERNEL);
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if (!queuedata) {
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err = -ENOMEM;
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goto cleanup_queue;
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}
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queuedata->shost = shost;
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q->queuedata = queuedata;
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/*
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* this is a silly hack. We should probably just queue as many
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* command as is recvd to userspace. uspace can then make
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* sure we do not overload the HBA
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*/
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q->nr_requests = shost->hostt->can_queue;
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/*
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* We currently only support software LLDs so this does
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* not matter for now. Do we need this for the cards we support?
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* If so we should make it a host template value.
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*/
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blk_queue_dma_alignment(q, 0);
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shost->uspace_req_q = q;
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for (i = 0; i < ARRAY_SIZE(queuedata->cmd_hash); i++)
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INIT_LIST_HEAD(&queuedata->cmd_hash[i]);
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spin_lock_init(&queuedata->cmd_hash_lock);
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return 0;
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cleanup_queue:
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blk_cleanup_queue(q);
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return err;
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}
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EXPORT_SYMBOL_GPL(scsi_tgt_alloc_queue);
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void scsi_tgt_free_queue(struct Scsi_Host *shost)
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{
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int i;
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unsigned long flags;
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struct request_queue *q = shost->uspace_req_q;
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struct scsi_cmnd *cmd;
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struct scsi_tgt_queuedata *qdata = q->queuedata;
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struct scsi_tgt_cmd *tcmd, *n;
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LIST_HEAD(cmds);
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spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
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for (i = 0; i < ARRAY_SIZE(qdata->cmd_hash); i++) {
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list_for_each_entry_safe(tcmd, n, &qdata->cmd_hash[i],
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hash_list) {
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list_del(&tcmd->hash_list);
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list_add(&tcmd->hash_list, &cmds);
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}
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}
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spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
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while (!list_empty(&cmds)) {
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tcmd = list_entry(cmds.next, struct scsi_tgt_cmd, hash_list);
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list_del(&tcmd->hash_list);
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cmd = tcmd->rq->special;
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shost->hostt->eh_abort_handler(cmd);
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scsi_tgt_cmd_destroy(cmd);
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}
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}
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EXPORT_SYMBOL_GPL(scsi_tgt_free_queue);
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struct Scsi_Host *scsi_tgt_cmd_to_host(struct scsi_cmnd *cmd)
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{
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struct scsi_tgt_queuedata *queue = cmd->request->q->queuedata;
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return queue->shost;
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}
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EXPORT_SYMBOL_GPL(scsi_tgt_cmd_to_host);
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/*
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* scsi_tgt_queue_command - queue command for userspace processing
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* @cmd: scsi command
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* @scsilun: scsi lun
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* @tag: unique value to identify this command for tmf
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*/
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int scsi_tgt_queue_command(struct scsi_cmnd *cmd, struct scsi_lun *scsilun,
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u64 tag)
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{
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struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
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int err;
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init_scsi_tgt_cmd(cmd->request, tcmd, tag);
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err = scsi_tgt_uspace_send_cmd(cmd, scsilun, tag);
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if (err)
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cmd_hashlist_del(cmd);
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return err;
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}
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EXPORT_SYMBOL_GPL(scsi_tgt_queue_command);
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/*
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* This is run from a interrpt handler normally and the unmap
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* needs process context so we must queue
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*/
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static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd)
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{
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struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
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dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request));
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scsi_tgt_uspace_send_status(cmd, tcmd->tag);
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INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy, cmd);
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queue_work(scsi_tgtd, &tcmd->work);
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}
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static int __scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
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{
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struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
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int err;
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|
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dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request));
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|
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err = shost->hostt->transfer_response(cmd, scsi_tgt_cmd_done);
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switch (err) {
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case SCSI_MLQUEUE_HOST_BUSY:
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case SCSI_MLQUEUE_DEVICE_BUSY:
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||||||
|
return -EAGAIN;
|
||||||
|
}
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
|
||||||
|
{
|
||||||
|
struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
|
||||||
|
int err;
|
||||||
|
|
||||||
|
err = __scsi_tgt_transfer_response(cmd);
|
||||||
|
if (!err)
|
||||||
|
return;
|
||||||
|
|
||||||
|
cmd->result = DID_BUS_BUSY << 16;
|
||||||
|
err = scsi_tgt_uspace_send_status(cmd, tcmd->tag);
|
||||||
|
if (err <= 0)
|
||||||
|
/* the eh will have to pick this up */
|
||||||
|
printk(KERN_ERR "Could not send cmd %p status\n", cmd);
|
||||||
|
}
|
||||||
|
|
||||||
|
static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask)
|
||||||
|
{
|
||||||
|
struct request *rq = cmd->request;
|
||||||
|
struct scsi_tgt_cmd *tcmd = rq->end_io_data;
|
||||||
|
int count;
|
||||||
|
|
||||||
|
cmd->use_sg = rq->nr_phys_segments;
|
||||||
|
cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask);
|
||||||
|
if (!cmd->request_buffer)
|
||||||
|
return -ENOMEM;
|
||||||
|
|
||||||
|
cmd->request_bufflen = rq->data_len;
|
||||||
|
|
||||||
|
dprintk("cmd %p addr %p cnt %d %lu\n", cmd, tcmd->buffer, cmd->use_sg,
|
||||||
|
rq_data_dir(rq));
|
||||||
|
count = blk_rq_map_sg(rq->q, rq, cmd->request_buffer);
|
||||||
|
if (likely(count <= cmd->use_sg)) {
|
||||||
|
cmd->use_sg = count;
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
eprintk("cmd %p addr %p cnt %d\n", cmd, tcmd->buffer, cmd->use_sg);
|
||||||
|
scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
|
||||||
|
return -EINVAL;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* TODO: test this crap and replace bio_map_user with new interface maybe */
|
||||||
|
static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
|
||||||
|
int rw)
|
||||||
|
{
|
||||||
|
struct request_queue *q = cmd->request->q;
|
||||||
|
struct request *rq = cmd->request;
|
||||||
|
void *uaddr = tcmd->buffer;
|
||||||
|
unsigned int len = tcmd->bufflen;
|
||||||
|
struct bio *bio;
|
||||||
|
int err;
|
||||||
|
|
||||||
|
while (len > 0) {
|
||||||
|
dprintk("%lx %u\n", (unsigned long) uaddr, len);
|
||||||
|
bio = bio_map_user(q, NULL, (unsigned long) uaddr, len, rw);
|
||||||
|
if (IS_ERR(bio)) {
|
||||||
|
err = PTR_ERR(bio);
|
||||||
|
dprintk("fail to map %lx %u %d %x\n",
|
||||||
|
(unsigned long) uaddr, len, err, cmd->cmnd[0]);
|
||||||
|
goto unmap_bios;
|
||||||
|
}
|
||||||
|
|
||||||
|
uaddr += bio->bi_size;
|
||||||
|
len -= bio->bi_size;
|
||||||
|
|
||||||
|
/*
|
||||||
|
* The first bio is added and merged. We could probably
|
||||||
|
* try to add others using scsi_merge_bio() but for now
|
||||||
|
* we keep it simple. The first bio should be pretty large
|
||||||
|
* (either hitting the 1 MB bio pages limit or a queue limit)
|
||||||
|
* already but for really large IO we may want to try and
|
||||||
|
* merge these.
|
||||||
|
*/
|
||||||
|
if (!rq->bio) {
|
||||||
|
blk_rq_bio_prep(q, rq, bio);
|
||||||
|
rq->data_len = bio->bi_size;
|
||||||
|
} else
|
||||||
|
/* put list of bios to transfer in next go around */
|
||||||
|
bio_list_add(&tcmd->xfer_list, bio);
|
||||||
|
}
|
||||||
|
|
||||||
|
cmd->offset = 0;
|
||||||
|
err = scsi_tgt_init_cmd(cmd, GFP_KERNEL);
|
||||||
|
if (err)
|
||||||
|
goto unmap_bios;
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
|
||||||
|
unmap_bios:
|
||||||
|
if (rq->bio) {
|
||||||
|
bio_unmap_user(rq->bio);
|
||||||
|
while ((bio = bio_list_pop(&tcmd->xfer_list)))
|
||||||
|
bio_unmap_user(bio);
|
||||||
|
}
|
||||||
|
|
||||||
|
return err;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int scsi_tgt_transfer_data(struct scsi_cmnd *);
|
||||||
|
|
||||||
|
static void scsi_tgt_data_transfer_done(struct scsi_cmnd *cmd)
|
||||||
|
{
|
||||||
|
struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
|
||||||
|
struct bio *bio;
|
||||||
|
int err;
|
||||||
|
|
||||||
|
/* should we free resources here on error ? */
|
||||||
|
if (cmd->result) {
|
||||||
|
send_uspace_err:
|
||||||
|
err = scsi_tgt_uspace_send_status(cmd, tcmd->tag);
|
||||||
|
if (err <= 0)
|
||||||
|
/* the tgt uspace eh will have to pick this up */
|
||||||
|
printk(KERN_ERR "Could not send cmd %p status\n", cmd);
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
|
||||||
|
dprintk("cmd %p request_bufflen %u bufflen %u\n",
|
||||||
|
cmd, cmd->request_bufflen, tcmd->bufflen);
|
||||||
|
|
||||||
|
scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
|
||||||
|
bio_list_add(&tcmd->xfer_done_list, cmd->request->bio);
|
||||||
|
|
||||||
|
tcmd->buffer += cmd->request_bufflen;
|
||||||
|
cmd->offset += cmd->request_bufflen;
|
||||||
|
|
||||||
|
if (!tcmd->xfer_list.head) {
|
||||||
|
scsi_tgt_transfer_response(cmd);
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
|
||||||
|
dprintk("cmd2 %p request_bufflen %u bufflen %u\n",
|
||||||
|
cmd, cmd->request_bufflen, tcmd->bufflen);
|
||||||
|
|
||||||
|
bio = bio_list_pop(&tcmd->xfer_list);
|
||||||
|
BUG_ON(!bio);
|
||||||
|
|
||||||
|
blk_rq_bio_prep(cmd->request->q, cmd->request, bio);
|
||||||
|
cmd->request->data_len = bio->bi_size;
|
||||||
|
err = scsi_tgt_init_cmd(cmd, GFP_ATOMIC);
|
||||||
|
if (err) {
|
||||||
|
cmd->result = DID_ERROR << 16;
|
||||||
|
goto send_uspace_err;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (scsi_tgt_transfer_data(cmd)) {
|
||||||
|
cmd->result = DID_NO_CONNECT << 16;
|
||||||
|
goto send_uspace_err;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static int scsi_tgt_transfer_data(struct scsi_cmnd *cmd)
|
||||||
|
{
|
||||||
|
int err;
|
||||||
|
struct Scsi_Host *host = scsi_tgt_cmd_to_host(cmd);
|
||||||
|
|
||||||
|
err = host->hostt->transfer_data(cmd, scsi_tgt_data_transfer_done);
|
||||||
|
switch (err) {
|
||||||
|
case SCSI_MLQUEUE_HOST_BUSY:
|
||||||
|
case SCSI_MLQUEUE_DEVICE_BUSY:
|
||||||
|
return -EAGAIN;
|
||||||
|
default:
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static int scsi_tgt_copy_sense(struct scsi_cmnd *cmd, unsigned long uaddr,
|
||||||
|
unsigned len)
|
||||||
|
{
|
||||||
|
char __user *p = (char __user *) uaddr;
|
||||||
|
|
||||||
|
if (copy_from_user(cmd->sense_buffer, p,
|
||||||
|
min_t(unsigned, SCSI_SENSE_BUFFERSIZE, len))) {
|
||||||
|
printk(KERN_ERR "Could not copy the sense buffer\n");
|
||||||
|
return -EIO;
|
||||||
|
}
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int scsi_tgt_abort_cmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
|
||||||
|
{
|
||||||
|
int err;
|
||||||
|
|
||||||
|
err = shost->hostt->eh_abort_handler(cmd);
|
||||||
|
if (err)
|
||||||
|
eprintk("fail to abort %p\n", cmd);
|
||||||
|
|
||||||
|
scsi_tgt_cmd_destroy(cmd);
|
||||||
|
return err;
|
||||||
|
}
|
||||||
|
|
||||||
|
static struct request *tgt_cmd_hash_lookup(struct request_queue *q, u64 tag)
|
||||||
|
{
|
||||||
|
struct scsi_tgt_queuedata *qdata = q->queuedata;
|
||||||
|
struct request *rq = NULL;
|
||||||
|
struct list_head *head;
|
||||||
|
struct scsi_tgt_cmd *tcmd;
|
||||||
|
unsigned long flags;
|
||||||
|
|
||||||
|
head = &qdata->cmd_hash[cmd_hashfn(tag)];
|
||||||
|
spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
|
||||||
|
list_for_each_entry(tcmd, head, hash_list) {
|
||||||
|
if (tcmd->tag == tag) {
|
||||||
|
rq = tcmd->rq;
|
||||||
|
list_del(&tcmd->hash_list);
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
|
||||||
|
|
||||||
|
return rq;
|
||||||
|
}
|
||||||
|
|
||||||
|
int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len,
|
||||||
|
unsigned long uaddr, u8 rw)
|
||||||
|
{
|
||||||
|
struct Scsi_Host *shost;
|
||||||
|
struct scsi_cmnd *cmd;
|
||||||
|
struct request *rq;
|
||||||
|
struct scsi_tgt_cmd *tcmd;
|
||||||
|
int err = 0;
|
||||||
|
|
||||||
|
dprintk("%d %llu %d %u %lx %u\n", host_no, (unsigned long long) tag,
|
||||||
|
result, len, uaddr, rw);
|
||||||
|
|
||||||
|
/* TODO: replace with a O(1) alg */
|
||||||
|
shost = scsi_host_lookup(host_no);
|
||||||
|
if (IS_ERR(shost)) {
|
||||||
|
printk(KERN_ERR "Could not find host no %d\n", host_no);
|
||||||
|
return -EINVAL;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (!shost->uspace_req_q) {
|
||||||
|
printk(KERN_ERR "Not target scsi host %d\n", host_no);
|
||||||
|
goto done;
|
||||||
|
}
|
||||||
|
|
||||||
|
rq = tgt_cmd_hash_lookup(shost->uspace_req_q, tag);
|
||||||
|
if (!rq) {
|
||||||
|
printk(KERN_ERR "Could not find tag %llu\n",
|
||||||
|
(unsigned long long) tag);
|
||||||
|
err = -EINVAL;
|
||||||
|
goto done;
|
||||||
|
}
|
||||||
|
cmd = rq->special;
|
||||||
|
|
||||||
|
dprintk("cmd %p result %d len %d bufflen %u %lu %x\n", cmd,
|
||||||
|
result, len, cmd->request_bufflen, rq_data_dir(rq), cmd->cmnd[0]);
|
||||||
|
|
||||||
|
if (result == TASK_ABORTED) {
|
||||||
|
scsi_tgt_abort_cmd(shost, cmd);
|
||||||
|
goto done;
|
||||||
|
}
|
||||||
|
/*
|
||||||
|
* store the userspace values here, the working values are
|
||||||
|
* in the request_* values
|
||||||
|
*/
|
||||||
|
tcmd = cmd->request->end_io_data;
|
||||||
|
tcmd->buffer = (void *)uaddr;
|
||||||
|
tcmd->bufflen = len;
|
||||||
|
cmd->result = result;
|
||||||
|
|
||||||
|
if (!tcmd->bufflen || cmd->request_buffer) {
|
||||||
|
err = __scsi_tgt_transfer_response(cmd);
|
||||||
|
goto done;
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* TODO: Do we need to handle case where request does not
|
||||||
|
* align with LLD.
|
||||||
|
*/
|
||||||
|
err = scsi_map_user_pages(rq->end_io_data, cmd, rw);
|
||||||
|
if (err) {
|
||||||
|
eprintk("%p %d\n", cmd, err);
|
||||||
|
err = -EAGAIN;
|
||||||
|
goto done;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* userspace failure */
|
||||||
|
if (cmd->result) {
|
||||||
|
if (status_byte(cmd->result) == CHECK_CONDITION)
|
||||||
|
scsi_tgt_copy_sense(cmd, uaddr, len);
|
||||||
|
err = __scsi_tgt_transfer_response(cmd);
|
||||||
|
goto done;
|
||||||
|
}
|
||||||
|
/* ask the target LLD to transfer the data to the buffer */
|
||||||
|
err = scsi_tgt_transfer_data(cmd);
|
||||||
|
|
||||||
|
done:
|
||||||
|
scsi_host_put(shost);
|
||||||
|
return err;
|
||||||
|
}
|
||||||
|
|
||||||
|
int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, int function, u64 tag,
|
||||||
|
struct scsi_lun *scsilun, void *data)
|
||||||
|
{
|
||||||
|
int err;
|
||||||
|
|
||||||
|
/* TODO: need to retry if this fails. */
|
||||||
|
err = scsi_tgt_uspace_send_tsk_mgmt(shost->host_no, function,
|
||||||
|
tag, scsilun, data);
|
||||||
|
if (err < 0)
|
||||||
|
eprintk("The task management request lost!\n");
|
||||||
|
return err;
|
||||||
|
}
|
||||||
|
EXPORT_SYMBOL_GPL(scsi_tgt_tsk_mgmt_request);
|
||||||
|
|
||||||
|
int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result)
|
||||||
|
{
|
||||||
|
struct Scsi_Host *shost;
|
||||||
|
int err = -EINVAL;
|
||||||
|
|
||||||
|
dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid);
|
||||||
|
|
||||||
|
shost = scsi_host_lookup(host_no);
|
||||||
|
if (IS_ERR(shost)) {
|
||||||
|
printk(KERN_ERR "Could not find host no %d\n", host_no);
|
||||||
|
return err;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (!shost->uspace_req_q) {
|
||||||
|
printk(KERN_ERR "Not target scsi host %d\n", host_no);
|
||||||
|
goto done;
|
||||||
|
}
|
||||||
|
|
||||||
|
err = shost->hostt->tsk_mgmt_response(mid, result);
|
||||||
|
done:
|
||||||
|
scsi_host_put(shost);
|
||||||
|
return err;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int __init scsi_tgt_init(void)
|
||||||
|
{
|
||||||
|
int err;
|
||||||
|
|
||||||
|
scsi_tgt_cmd_cache = kmem_cache_create("scsi_tgt_cmd",
|
||||||
|
sizeof(struct scsi_tgt_cmd),
|
||||||
|
0, 0, NULL, NULL);
|
||||||
|
if (!scsi_tgt_cmd_cache)
|
||||||
|
return -ENOMEM;
|
||||||
|
|
||||||
|
scsi_tgtd = create_workqueue("scsi_tgtd");
|
||||||
|
if (!scsi_tgtd) {
|
||||||
|
err = -ENOMEM;
|
||||||
|
goto free_kmemcache;
|
||||||
|
}
|
||||||
|
|
||||||
|
err = scsi_tgt_if_init();
|
||||||
|
if (err)
|
||||||
|
goto destroy_wq;
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
|
||||||
|
destroy_wq:
|
||||||
|
destroy_workqueue(scsi_tgtd);
|
||||||
|
free_kmemcache:
|
||||||
|
kmem_cache_destroy(scsi_tgt_cmd_cache);
|
||||||
|
return err;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void __exit scsi_tgt_exit(void)
|
||||||
|
{
|
||||||
|
destroy_workqueue(scsi_tgtd);
|
||||||
|
scsi_tgt_if_exit();
|
||||||
|
kmem_cache_destroy(scsi_tgt_cmd_cache);
|
||||||
|
}
|
||||||
|
|
||||||
|
module_init(scsi_tgt_init);
|
||||||
|
module_exit(scsi_tgt_exit);
|
||||||
|
|
||||||
|
MODULE_DESCRIPTION("SCSI target core");
|
||||||
|
MODULE_LICENSE("GPL");
|
||||||
25
drivers/scsi/scsi_tgt_priv.h
Normal file
25
drivers/scsi/scsi_tgt_priv.h
Normal file
@ -0,0 +1,25 @@
|
|||||||
|
struct scsi_cmnd;
|
||||||
|
struct scsi_lun;
|
||||||
|
struct Scsi_Host;
|
||||||
|
struct task_struct;
|
||||||
|
|
||||||
|
/* tmp - will replace with SCSI logging stuff */
|
||||||
|
#define eprintk(fmt, args...) \
|
||||||
|
do { \
|
||||||
|
printk("%s(%d) " fmt, __FUNCTION__, __LINE__, ##args); \
|
||||||
|
} while (0)
|
||||||
|
|
||||||
|
#define dprintk(fmt, args...)
|
||||||
|
/* #define dprintk eprintk */
|
||||||
|
|
||||||
|
extern void scsi_tgt_if_exit(void);
|
||||||
|
extern int scsi_tgt_if_init(void);
|
||||||
|
|
||||||
|
extern int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun,
|
||||||
|
u64 tag);
|
||||||
|
extern int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag);
|
||||||
|
extern int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len,
|
||||||
|
unsigned long uaddr, u8 rw);
|
||||||
|
extern int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag,
|
||||||
|
struct scsi_lun *scsilun, void *data);
|
||||||
|
extern int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result);
|
||||||
19
include/scsi/scsi_tgt.h
Normal file
19
include/scsi/scsi_tgt.h
Normal file
@ -0,0 +1,19 @@
|
|||||||
|
/*
|
||||||
|
* SCSI target definitions
|
||||||
|
*/
|
||||||
|
|
||||||
|
#include <linux/dma-mapping.h>
|
||||||
|
|
||||||
|
struct Scsi_Host;
|
||||||
|
struct scsi_cmnd;
|
||||||
|
struct scsi_lun;
|
||||||
|
|
||||||
|
extern struct Scsi_Host *scsi_tgt_cmd_to_host(struct scsi_cmnd *);
|
||||||
|
extern int scsi_tgt_alloc_queue(struct Scsi_Host *);
|
||||||
|
extern void scsi_tgt_free_queue(struct Scsi_Host *);
|
||||||
|
extern int scsi_tgt_queue_command(struct scsi_cmnd *, struct scsi_lun *, u64);
|
||||||
|
extern int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *, int, u64, struct scsi_lun *,
|
||||||
|
void *);
|
||||||
|
extern struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *,
|
||||||
|
enum dma_data_direction, gfp_t);
|
||||||
|
extern void scsi_host_put_command(struct Scsi_Host *, struct scsi_cmnd *);
|
||||||
Loading…
Reference in New Issue
Block a user