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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2006-11-16 19:24:13 +0900
committerJames Bottomley <jejb@mulgrave.il.steeleye.com>2006-11-25 13:17:18 -0600
commit5a55c2596f55e3a60f7502d0dfcfa0d20241e5ac (patch)
tree30bee283b134036d67b15e597270f3718a5e41e5 /drivers/scsi/scsi_tgt_lib.c
parentb58d91547fb17c65ad621f3f98b1f2c228c812a5 (diff)
downloadvexpress-lsk-5a55c2596f55e3a60f7502d0dfcfa0d20241e5ac.tar.gz
[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>
Diffstat (limited to 'drivers/scsi/scsi_tgt_lib.c')
-rw-r--r--drivers/scsi/scsi_tgt_lib.c742
1 files changed, 742 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
new file mode 100644
index 00000000000..39da5cd6fb6
--- /dev/null
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -0,0 +1,742 @@
+/*
+ * 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 <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_tgt.h>
+#include <../drivers/md/dm-bio-list.h>
+
+#include "scsi_tgt_priv.h"
+
+static struct workqueue_struct *scsi_tgtd;
+static kmem_cache_t *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 replace the lists with a large bio */
+ struct bio_list xfer_done_list;
+ struct bio_list xfer_list;
+
+ struct list_head hash_list;
+ struct request *rq;
+ u64 tag;
+
+ void *buffer;
+ unsigned bufflen;
+};
+
+#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;
+
+ 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;
+
+ memset(cmd, 0, sizeof(*cmd));
+ cmd->sc_data_direction = data_dir;
+ cmd->jiffies_at_alloc = jiffies;
+ cmd->request = rq;
+
+ rq->special = cmd;
+ rq->cmd_type = REQ_TYPE_SPECIAL;
+ rq->cmd_flags |= REQ_TYPE_BLOCK_PC;
+ rq->end_io_data = tcmd;
+
+ bio_list_init(&tcmd->xfer_list);
+ bio_list_init(&tcmd->xfer_done_list);
+ 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, &shost->shost_gendev);
+}
+EXPORT_SYMBOL_GPL(scsi_host_put_command);
+
+static void scsi_unmap_user_pages(struct scsi_tgt_cmd *tcmd)
+{
+ struct bio *bio;
+
+ /* must call bio_endio in case bio was bounced */
+ while ((bio = bio_list_pop(&tcmd->xfer_done_list))) {
+ bio_endio(bio, bio->bi_size, 0);
+ bio_unmap_user(bio);
+ }
+
+ while ((bio = bio_list_pop(&tcmd->xfer_list))) {
+ bio_endio(bio, bio->bi_size, 0);
+ bio_unmap_user(bio);
+ }
+}
+
+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_tgt_cmd_destroy(void *data)
+{
+ struct scsi_cmnd *cmd = data;
+ struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
+
+ dprintk("cmd %p %d %lu\n", cmd, cmd->sc_data_direction,
+ rq_data_dir(cmd->request));
+ /*
+ * We fix rq->cmd_flags here since when we told bio_map_user
+ * to write vm for WRITE commands, blk_rq_bio_prep set
+ * rq_data_dir the flags to READ.
+ */
+ if (cmd->sc_data_direction == DMA_TO_DEVICE)
+ cmd->request->cmd_flags |= REQ_RW;
+ else
+ cmd->request->cmd_flags &= ~REQ_RW;
+
+ scsi_unmap_user_pages(tcmd);
+ 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 tag)
+{
+ struct scsi_tgt_queuedata *qdata = rq->q->queuedata;
+ unsigned long flags;
+ struct list_head *head;
+
+ tcmd->tag = tag;
+ 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->hostt->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_del(&tcmd->hash_list);
+ list_add(&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(cmd);
+ }
+}
+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, 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, tag);
+ err = scsi_tgt_uspace_send_cmd(cmd, scsilun, tag);
+ if (err)
+ cmd_hashlist_del(cmd);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(scsi_tgt_queue_command);
+
+/*
+ * This is run from a interrpt 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 %lu\n", cmd, rq_data_dir(cmd->request));
+
+ scsi_tgt_uspace_send_status(cmd, tcmd->tag);
+ INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy, 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 %lu\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;
+}
+
+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");