diff options
Diffstat (limited to 'drivers/scsi/scsi_tgt_lib.c')
| -rw-r--r-- | drivers/scsi/scsi_tgt_lib.c | 661 |
1 files changed, 0 insertions, 661 deletions
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c deleted file mode 100644 index e51add05fb8d..000000000000 --- a/drivers/scsi/scsi_tgt_lib.c +++ /dev/null @@ -1,661 +0,0 @@ -/* - * SCSI target lib functions - * - * Copyright (C) 2005 Mike Christie <michaelc@cs.wisc.edu> - * Copyright (C) 2005 FUJITA Tomonori <tomof@acm.org> - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of the - * License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA - * 02110-1301 USA - */ -#include <linux/blkdev.h> -#include <linux/hash.h> -#include <linux/module.h> -#include <linux/pagemap.h> -#include <linux/slab.h> -#include <scsi/scsi.h> -#include <scsi/scsi_cmnd.h> -#include <scsi/scsi_device.h> -#include <scsi/scsi_host.h> -#include <scsi/scsi_transport.h> -#include <scsi/scsi_tgt.h> - -#include "scsi_tgt_priv.h" - -static struct workqueue_struct *scsi_tgtd; -static struct kmem_cache *scsi_tgt_cmd_cache; - -/* - * TODO: this struct will be killed when the block layer supports large bios - * and James's work struct code is in - */ -struct scsi_tgt_cmd { - /* TODO replace work with James b's code */ - struct work_struct work; - /* TODO fix limits of some drivers */ - struct bio *bio; - - struct list_head hash_list; - struct request *rq; - u64 itn_id; - u64 tag; -}; - -#define TGT_HASH_ORDER 4 -#define cmd_hashfn(tag) hash_long((unsigned long) (tag), TGT_HASH_ORDER) - -struct scsi_tgt_queuedata { - struct Scsi_Host *shost; - struct list_head cmd_hash[1 << TGT_HASH_ORDER]; - spinlock_t cmd_hash_lock; -}; - -/* - * Function: scsi_host_get_command() - * - * Purpose: Allocate and setup a scsi command block and blk request - * - * Arguments: shost - scsi host - * data_dir - dma data dir - * gfp_mask- allocator flags - * - * Returns: The allocated scsi command structure. - * - * This should be called by target LLDs to get a command. - */ -struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *shost, - enum dma_data_direction data_dir, - gfp_t gfp_mask) -{ - int write = (data_dir == DMA_TO_DEVICE); - struct request *rq; - struct scsi_cmnd *cmd; - struct scsi_tgt_cmd *tcmd; - - /* Bail if we can't get a reference to the device */ - if (!get_device(&shost->shost_gendev)) - return NULL; - - tcmd = kmem_cache_alloc(scsi_tgt_cmd_cache, GFP_ATOMIC); - if (!tcmd) - goto put_dev; - - /* - * The blk helpers are used to the READ/WRITE requests - * transferring data from a initiator point of view. Since - * we are in target mode we want the opposite. - */ - rq = blk_get_request(shost->uspace_req_q, !write, gfp_mask); - if (!rq) - goto free_tcmd; - - cmd = __scsi_get_command(shost, gfp_mask); - if (!cmd) - goto release_rq; - - cmd->sc_data_direction = data_dir; - cmd->jiffies_at_alloc = jiffies; - cmd->request = rq; - - cmd->cmnd = rq->cmd; - - rq->special = cmd; - rq->cmd_type = REQ_TYPE_SPECIAL; - rq->cmd_flags |= REQ_TYPE_BLOCK_PC; - rq->end_io_data = tcmd; - - tcmd->rq = rq; - - return cmd; - -release_rq: - blk_put_request(rq); -free_tcmd: - kmem_cache_free(scsi_tgt_cmd_cache, tcmd); -put_dev: - put_device(&shost->shost_gendev); - return NULL; - -} -EXPORT_SYMBOL_GPL(scsi_host_get_command); - -/* - * Function: scsi_host_put_command() - * - * Purpose: Free a scsi command block - * - * Arguments: shost - scsi host - * cmd - command block to free - * - * Returns: Nothing. - * - * Notes: The command must not belong to any lists. - */ -void scsi_host_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd) -{ - struct request_queue *q = shost->uspace_req_q; - struct request *rq = cmd->request; - struct scsi_tgt_cmd *tcmd = rq->end_io_data; - unsigned long flags; - - kmem_cache_free(scsi_tgt_cmd_cache, tcmd); - - spin_lock_irqsave(q->queue_lock, flags); - __blk_put_request(q, rq); - spin_unlock_irqrestore(q->queue_lock, flags); - - __scsi_put_command(shost, cmd); - put_device(&shost->shost_gendev); -} -EXPORT_SYMBOL_GPL(scsi_host_put_command); - -static void cmd_hashlist_del(struct scsi_cmnd *cmd) -{ - struct request_queue *q = cmd->request->q; - struct scsi_tgt_queuedata *qdata = q->queuedata; - unsigned long flags; - struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; - - spin_lock_irqsave(&qdata->cmd_hash_lock, flags); - list_del(&tcmd->hash_list); - spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); -} - -static void scsi_unmap_user_pages(struct scsi_tgt_cmd *tcmd) -{ - blk_rq_unmap_user(tcmd->bio); -} - -static void scsi_tgt_cmd_destroy(struct work_struct *work) -{ - struct scsi_tgt_cmd *tcmd = - container_of(work, struct scsi_tgt_cmd, work); - struct scsi_cmnd *cmd = tcmd->rq->special; - - dprintk("cmd %p %d %u\n", cmd, cmd->sc_data_direction, - rq_data_dir(cmd->request)); - scsi_unmap_user_pages(tcmd); - tcmd->rq->bio = NULL; - scsi_host_put_command(scsi_tgt_cmd_to_host(cmd), cmd); -} - -static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd, - u64 itn_id, u64 tag) -{ - struct scsi_tgt_queuedata *qdata = rq->q->queuedata; - unsigned long flags; - struct list_head *head; - - tcmd->itn_id = itn_id; - tcmd->tag = tag; - tcmd->bio = NULL; - INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy); - spin_lock_irqsave(&qdata->cmd_hash_lock, flags); - head = &qdata->cmd_hash[cmd_hashfn(tag)]; - list_add(&tcmd->hash_list, head); - spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); -} - -/* - * scsi_tgt_alloc_queue - setup queue used for message passing - * shost: scsi host - * - * This should be called by the LLD after host allocation. - * And will be released when the host is released. - */ -int scsi_tgt_alloc_queue(struct Scsi_Host *shost) -{ - struct scsi_tgt_queuedata *queuedata; - struct request_queue *q; - int err, i; - - /* - * Do we need to send a netlink event or should uspace - * just respond to the hotplug event? - */ - q = __scsi_alloc_queue(shost, NULL); - if (!q) - return -ENOMEM; - - queuedata = kzalloc(sizeof(*queuedata), GFP_KERNEL); - if (!queuedata) { - err = -ENOMEM; - goto cleanup_queue; - } - queuedata->shost = shost; - q->queuedata = queuedata; - - /* - * this is a silly hack. We should probably just queue as many - * command as is recvd to userspace. uspace can then make - * sure we do not overload the HBA - */ - q->nr_requests = shost->can_queue; - /* - * We currently only support software LLDs so this does - * not matter for now. Do we need this for the cards we support? - * If so we should make it a host template value. - */ - blk_queue_dma_alignment(q, 0); - shost->uspace_req_q = q; - - for (i = 0; i < ARRAY_SIZE(queuedata->cmd_hash); i++) - INIT_LIST_HEAD(&queuedata->cmd_hash[i]); - spin_lock_init(&queuedata->cmd_hash_lock); - - return 0; - -cleanup_queue: - blk_cleanup_queue(q); - return err; -} -EXPORT_SYMBOL_GPL(scsi_tgt_alloc_queue); - -void scsi_tgt_free_queue(struct Scsi_Host *shost) -{ - int i; - unsigned long flags; - struct request_queue *q = shost->uspace_req_q; - struct scsi_cmnd *cmd; - struct scsi_tgt_queuedata *qdata = q->queuedata; - struct scsi_tgt_cmd *tcmd, *n; - LIST_HEAD(cmds); - - spin_lock_irqsave(&qdata->cmd_hash_lock, flags); - - for (i = 0; i < ARRAY_SIZE(qdata->cmd_hash); i++) { - list_for_each_entry_safe(tcmd, n, &qdata->cmd_hash[i], - hash_list) - list_move(&tcmd->hash_list, &cmds); - } - - spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); - - while (!list_empty(&cmds)) { - tcmd = list_entry(cmds.next, struct scsi_tgt_cmd, hash_list); - list_del(&tcmd->hash_list); - cmd = tcmd->rq->special; - - shost->hostt->eh_abort_handler(cmd); - scsi_tgt_cmd_destroy(&tcmd->work); - } -} -EXPORT_SYMBOL_GPL(scsi_tgt_free_queue); - -struct Scsi_Host *scsi_tgt_cmd_to_host(struct scsi_cmnd *cmd) -{ - struct scsi_tgt_queuedata *queue = cmd->request->q->queuedata; - return queue->shost; -} -EXPORT_SYMBOL_GPL(scsi_tgt_cmd_to_host); - -/* - * scsi_tgt_queue_command - queue command for userspace processing - * @cmd: scsi command - * @scsilun: scsi lun - * @tag: unique value to identify this command for tmf - */ -int scsi_tgt_queue_command(struct scsi_cmnd *cmd, u64 itn_id, - struct scsi_lun *scsilun, u64 tag) -{ - struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; - int err; - - init_scsi_tgt_cmd(cmd->request, tcmd, itn_id, tag); - err = scsi_tgt_uspace_send_cmd(cmd, itn_id, scsilun, tag); - if (err) - cmd_hashlist_del(cmd); - - return err; -} -EXPORT_SYMBOL_GPL(scsi_tgt_queue_command); - -/* - * This is run from a interrupt handler normally and the unmap - * needs process context so we must queue - */ -static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd) -{ - struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data; - - dprintk("cmd %p %u\n", cmd, rq_data_dir(cmd->request)); - - scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag); - - scsi_release_buffers(cmd); - - queue_work(scsi_tgtd, &tcmd->work); -} - -static int scsi_tgt_transfer_response(struct scsi_cmnd *cmd) -{ - struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); - int err; - - dprintk("cmd %p %u\n", cmd, rq_data_dir(cmd->request)); - - err = shost->hostt->transfer_response(cmd, scsi_tgt_cmd_done); - switch (err) { - case SCSI_MLQUEUE_HOST_BUSY: - case SCSI_MLQUEUE_DEVICE_BUSY: - return -EAGAIN; - } - return 0; -} - -/* 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, - unsigned long uaddr, unsigned int len, int rw) -{ - struct request_queue *q = cmd->request->q; - struct request *rq = cmd->request; - int err; - - dprintk("%lx %u\n", uaddr, len); - err = blk_rq_map_user(q, rq, NULL, (void *)uaddr, len, GFP_KERNEL); - if (err) { - /* - * TODO: need to fixup sg_tablesize, max_segment_size, - * max_sectors, etc for modern HW and software drivers - * where this value is bogus. - * - * TODO2: we can alloc a reserve buffer of max size - * we can handle and do the slow copy path for really large - * IO. - */ - eprintk("Could not handle request of size %u.\n", len); - return err; - } - - tcmd->bio = rq->bio; - err = scsi_init_io(cmd, GFP_KERNEL); - if (err) { - scsi_release_buffers(cmd); - goto unmap_rq; - } - /* - * we use REQ_TYPE_BLOCK_PC so scsi_init_io doesn't set the - * length for us. - */ - cmd->sdb.length = blk_rq_bytes(rq); - - return 0; - -unmap_rq: - scsi_unmap_user_pages(tcmd); - return err; -} - -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) -{ - struct scsi_tgt_cmd *tcmd; - int err; - - err = shost->hostt->eh_abort_handler(cmd); - if (err) - eprintk("fail to abort %p\n", cmd); - - tcmd = cmd->request->end_io_data; - scsi_tgt_cmd_destroy(&tcmd->work); - 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 itn_id, int result, u64 tag, - unsigned long uaddr, u32 len, unsigned long sense_uaddr, - u32 sense_len, 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 (!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 scb %x result %d len %d bufflen %u %u %x\n", - cmd, cmd->cmnd[0], result, len, scsi_bufflen(cmd), - 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; - cmd->result = result; - - if (cmd->result == SAM_STAT_CHECK_CONDITION) - scsi_tgt_copy_sense(cmd, sense_uaddr, sense_len); - - if (len) { - err = scsi_map_user_pages(rq->end_io_data, cmd, uaddr, len, rw); - if (err) { - /* - * user-space daemon bugs or OOM - * TODO: we can do better for OOM. - */ - struct scsi_tgt_queuedata *qdata; - struct list_head *head; - unsigned long flags; - - eprintk("cmd %p ret %d uaddr %lx len %d rw %d\n", - cmd, err, uaddr, len, rw); - - qdata = shost->uspace_req_q->queuedata; - head = &qdata->cmd_hash[cmd_hashfn(tcmd->tag)]; - - spin_lock_irqsave(&qdata->cmd_hash_lock, flags); - list_add(&tcmd->hash_list, head); - spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags); - - goto done; - } - } - err = scsi_tgt_transfer_response(cmd); -done: - scsi_host_put(shost); - return err; -} - -int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, u64 itn_id, - 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, itn_id, - 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 itn_id, 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 (!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->transportt->tsk_mgmt_response(shost, itn_id, mid, result); -done: - scsi_host_put(shost); - return err; -} - -int scsi_tgt_it_nexus_create(struct Scsi_Host *shost, u64 itn_id, - char *initiator) -{ - int err; - - /* TODO: need to retry if this fails. */ - err = scsi_tgt_uspace_send_it_nexus_request(shost->host_no, itn_id, 0, - initiator); - if (err < 0) - eprintk("The i_t_neuxs request lost, %d %llx!\n", - shost->host_no, (unsigned long long)itn_id); - return err; -} -EXPORT_SYMBOL_GPL(scsi_tgt_it_nexus_create); - -int scsi_tgt_it_nexus_destroy(struct Scsi_Host *shost, u64 itn_id) -{ - int err; - - /* TODO: need to retry if this fails. */ - err = scsi_tgt_uspace_send_it_nexus_request(shost->host_no, - itn_id, 1, NULL); - if (err < 0) - eprintk("The i_t_neuxs request lost, %d %llx!\n", - shost->host_no, (unsigned long long)itn_id); - return err; -} -EXPORT_SYMBOL_GPL(scsi_tgt_it_nexus_destroy); - -int scsi_tgt_kspace_it_nexus_rsp(int host_no, u64 itn_id, int result) -{ - struct Scsi_Host *shost; - int err = -EINVAL; - - dprintk("%d %d%llx\n", host_no, result, (unsigned long long)itn_id); - - shost = scsi_host_lookup(host_no); - if (!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->transportt->it_nexus_response(shost, itn_id, result); -done: - scsi_host_put(shost); - return err; -} - -static int __init scsi_tgt_init(void) -{ - int err; - - scsi_tgt_cmd_cache = KMEM_CACHE(scsi_tgt_cmd, 0); - if (!scsi_tgt_cmd_cache) - return -ENOMEM; - - scsi_tgtd = alloc_workqueue("scsi_tgtd", 0, 1); - 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"); |