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path: root/drivers/scsi/scsi_tgt_lib.c
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Diffstat (limited to 'drivers/scsi/scsi_tgt_lib.c')
-rw-r--r--drivers/scsi/scsi_tgt_lib.c261
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;