1 files changed, 69 insertions, 192 deletions

diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index d402aff5f314..2570f48a69c7 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -28,7 +28,6 @@
 #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"
 
@@ -42,16 +41,12 @@ static struct kmem_cache *scsi_tgt_cmd_cache;
 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;
+        /* TODO fix limits of some drivers */
+        struct bio *bio;
 
         struct list_head hash_list;
         struct request *rq;
         u64 tag;
-
-        void *buffer;
-        unsigned bufflen;
 };
 
 #define TGT_HASH_ORDER  4
@@ -93,7 +88,12 @@ struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *shost,
         if (!tcmd)
                 goto put_dev;
 
-        rq = blk_get_request(shost->uspace_req_q, write, gfp_mask);
+        /*
+         * The blk helpers are used to the READ/WRITE requests
+         * transfering 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;
 
@@ -111,8 +111,6 @@ struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *shost,
         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;
@@ -157,22 +155,6 @@ void scsi_host_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
 }
 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;
@@ -185,6 +167,11 @@ static void cmd_hashlist_del(struct scsi_cmnd *cmd)
         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 =
@@ -193,16 +180,6 @@ static void scsi_tgt_cmd_destroy(struct work_struct *work)
 
         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);
 }
@@ -215,6 +192,7 @@ static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd,
         struct list_head *head;
 
         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)];
@@ -349,10 +327,14 @@ static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd)
         dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request));
 
         scsi_tgt_uspace_send_status(cmd, tcmd->tag);
+
+        if (cmd->request_buffer)
+                scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
+
         queue_work(scsi_tgtd, &tcmd->work);
 }
 
-static int __scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
+static int scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
 {
         struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
         int err;
@@ -365,30 +347,12 @@ static int __scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
         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;
@@ -398,143 +362,54 @@ static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask)
 
         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));
+        dprintk("cmd %p cnt %d %lu\n", cmd, 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);
+        eprintk("cmd %p cnt %d\n", cmd, 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)
+                               unsigned long uaddr, unsigned int len, 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;
-
+        dprintk("%lx %u\n", uaddr, len);
+        err = blk_rq_map_user(q, rq, (void *)uaddr, len);
+        if (err) {
                 /*
-                 * 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.
+                 * 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.
                  */
-                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);
+                eprintk("Could not handle request of size %u.\n", len);
+                return err;
         }
 
-        cmd->offset = 0;
+        tcmd->bio = rq->bio;
         err = scsi_tgt_init_cmd(cmd, GFP_KERNEL);
         if (err)
-                goto unmap_bios;
+                goto unmap_rq;
 
         return 0;
 
-unmap_bios:
-        if (rq->bio) {
-                bio_unmap_user(rq->bio);
-                while ((bio = bio_list_pop(&tcmd->xfer_list)))
-                        bio_unmap_user(bio);
-        }
-
+unmap_rq:
+        scsi_unmap_user_pages(tcmd);
         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)
 {
@@ -584,8 +459,9 @@ static struct request *tgt_cmd_hash_lookup(struct request_queue *q, u64 tag)
         return rq;
 }
 
-int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len,
-                         unsigned long uaddr, u8 rw)
+int scsi_tgt_kspace_exec(int host_no, 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;
@@ -617,8 +493,9 @@ int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len,
         }
         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]);
+        dprintk("cmd %p scb %x result %d len %d bufflen %u %lu %x\n",
+                cmd, cmd->cmnd[0], result, len, cmd->request_bufflen,
+                rq_data_dir(rq), cmd->cmnd[0]);
 
         if (result == TASK_ABORTED) {
                 scsi_tgt_abort_cmd(shost, cmd);
@@ -629,36 +506,36 @@ int scsi_tgt_kspace_exec(int host_no, u64 tag, int result, u32 len,
          * 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;
-        }
+        if (cmd->result == SAM_STAT_CHECK_CONDITION)
+                scsi_tgt_copy_sense(cmd, sense_uaddr, sense_len);
 
-        /*
-         * 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;
-        }
+        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;
 
-        /* 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);
+                        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;