This patch moves scsi_get_host_command and scsi_put_host_command to
scsi_tgt_lib.c from scsi.c
A target driver allocates scsi_cmnd structure via
scsi_get_host_command, then pass it to tgt core via
scsi_tgt_queue_command. scsi_tgt_queue_command could fail because it
needs to allocate scsi_tgt_cmd structure (for tgt specific data).
Allocating scsi_tgt_cmd structure in scsi_host_get_command simplifies
target drivers.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
drivers/scsi/scsi.c | 102 ++++------------------------------------
drivers/scsi/scsi_tgt_lib.c | 109 +++++++++++++++++++++++++++++++++++++------
include/scsi/scsi_cmnd.h | 6 +-
include/scsi/scsi_tgt.h | 4 ++
4 files changed, 112 insertions(+), 109 deletions(-)
da608da5bd0b59864bf552f31ff3676d866eb3b5
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 9c22465..1d2fbe0 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -212,8 +212,7 @@ static struct scsi_host_cmd_pool scsi_cm
static DEFINE_MUTEX(host_cmd_pool_mutex);
-static struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost,
- gfp_t gfp_mask)
+struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
{
struct scsi_cmnd *cmd;
@@ -234,58 +233,7 @@ static struct scsi_cmnd *__scsi_get_comm
return cmd;
}
-
-/*
- * 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;
-
- /* Bail if we can't get a reference to the device */
- if (!get_device(&shost->shost_gendev))
- return NULL;
-
- rq = blk_get_request(shost->uspace_req_q, write, gfp_mask);
- if (!rq)
- goto put_dev;
-
- 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->flags |= REQ_SPECIAL | REQ_BLOCK_PC;
-
- return cmd;
-
-release_rq:
- blk_put_request(rq);
-put_dev:
- put_device(&shost->shost_gendev);
- return NULL;
-
-}
-EXPORT_SYMBOL_GPL(scsi_host_get_command);
+EXPORT_SYMBOL_GPL(__scsi_get_command);
/*
* Function: scsi_get_command()
@@ -322,25 +270,12 @@ struct scsi_cmnd *scsi_get_command(struc
put_device(&dev->sdev_gendev);
return cmd;
-}
+}
EXPORT_SYMBOL(scsi_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)
+void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd,
+ struct device *dev)
{
- struct request_queue *q = shost->uspace_req_q;
- struct request *rq = cmd->request;
unsigned long flags;
/* changing locks here, don't need to restore the irq state */
@@ -349,18 +284,14 @@ void scsi_host_put_command(struct Scsi_H
list_add(&cmd->list, &shost->free_list);
cmd = NULL;
}
- spin_unlock(&shost->free_list_lock);
-
- spin_lock(q->queue_lock);
- __blk_put_request(q, rq);
- spin_unlock_irqrestore(q->queue_lock, flags);
+ spin_unlock_irqrestore(&shost->free_list_lock, flags);
if (likely(cmd != NULL))
kmem_cache_free(shost->cmd_pool->slab, cmd);
- put_device(&shost->shost_gendev);
+ put_device(dev);
}
-EXPORT_SYMBOL_GPL(scsi_host_put_command);
+EXPORT_SYMBOL(__scsi_put_command);
/*
* Function: scsi_put_command()
@@ -376,26 +307,15 @@ EXPORT_SYMBOL_GPL(scsi_host_put_command)
void scsi_put_command(struct scsi_cmnd *cmd)
{
struct scsi_device *sdev = cmd->device;
- struct Scsi_Host *shost = sdev->host;
unsigned long flags;
-
+
/* serious error if the command hasn't come from a device list */
spin_lock_irqsave(&cmd->device->list_lock, flags);
BUG_ON(list_empty(&cmd->list));
list_del_init(&cmd->list);
- spin_unlock(&cmd->device->list_lock);
- /* changing locks here, don't need to restore the irq state */
- spin_lock(&shost->free_list_lock);
- if (unlikely(list_empty(&shost->free_list))) {
- list_add(&cmd->list, &shost->free_list);
- cmd = NULL;
- }
- spin_unlock_irqrestore(&shost->free_list_lock, flags);
-
- if (likely(cmd != NULL))
- kmem_cache_free(shost->cmd_pool->slab, cmd);
+ spin_unlock_irqrestore(&cmd->device->list_lock, flags);
- put_device(&sdev->sdev_gendev);
+ __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev);
}
EXPORT_SYMBOL(scsi_put_command);
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 5a98fc4..2385db0 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -67,6 +67,95 @@ struct scsi_tgt_queuedata {
struct list_head cmd_req;
};
+/*
+ * 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->flags |= REQ_SPECIAL | REQ_BLOCK_PC;
+ rq->end_io_data = tcmd;
+
+ 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.
+ */
+static 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);
+}
+
static void scsi_unmap_user_pages(struct scsi_tgt_cmd *tcmd)
{
struct bio *bio;
@@ -107,7 +196,6 @@ static void scsi_tgt_cmd_destroy(void *d
cmd->request->flags &= ~1UL;
scsi_unmap_user_pages(tcmd);
- kmem_cache_free(scsi_tgt_cmd_cache, tcmd);
scsi_host_put_command(scsi_tgt_cmd_to_host(cmd), cmd);
}
@@ -174,13 +262,13 @@ out:
goto retry;
}
-/**
+/*
* 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;
@@ -241,28 +329,19 @@ struct Scsi_Host *scsi_tgt_cmd_to_host(s
}
EXPORT_SYMBOL_GPL(scsi_tgt_cmd_to_host);
-/**
+/*
* scsi_tgt_queue_command - queue command for userspace processing
* @cmd: scsi command
* @scsilun: scsi lun
* @noblock: set to nonzero if the command should be queued
- **/
+ */
int scsi_tgt_queue_command(struct scsi_cmnd *cmd, struct scsi_lun *scsilun,
u64 tag)
{
struct request_queue *q = cmd->request->q;
struct scsi_tgt_queuedata *qdata = q->queuedata;
unsigned long flags;
- struct scsi_tgt_cmd *tcmd;
-
- /*
- * It would be better to allocate scsi_tgt_cmd structure in
- * scsi_host_get_command and not to fail due to OOM.
- */
- tcmd = kmem_cache_alloc(scsi_tgt_cmd_cache, GFP_ATOMIC);
- if (!tcmd)
- return -ENOMEM;
- cmd->request->end_io_data = tcmd;
+ struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
bio_list_init(&tcmd->xfer_list);
bio_list_init(&tcmd->xfer_done_list);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 51156c7..c822bc2 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -150,11 +150,11 @@ struct scsi_cmnd {
#define SCSI_STATE_MLQUEUE 0x100b
-extern struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *,
- enum dma_data_direction, gfp_t);
extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
-extern void scsi_host_put_command(struct Scsi_Host *, struct scsi_cmnd *);
+extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
extern void scsi_put_command(struct scsi_cmnd *);
+extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
+ struct device *);
extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
extern void scsi_finish_command(struct scsi_cmnd *cmd);
extern struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
diff --git a/include/scsi/scsi_tgt.h b/include/scsi/scsi_tgt.h
index 2d65be7..61e8ee9 100644
--- a/include/scsi/scsi_tgt.h
+++ b/include/scsi/scsi_tgt.h
@@ -2,6 +2,8 @@
* SCSI target definitions
*/
+#include <linux/dma-mapping.h>
+
struct Scsi_Host;
struct scsi_cmnd;
struct scsi_lun;
@@ -11,3 +13,5 @@ extern int scsi_tgt_alloc_queue(struct S
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);
--
1.1.5
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