[SCSI] simplify command allocation and freeing a bit

Just have one level of alloc/free functions that take a host instead
of two levels for the allocation and different calling conventions
for the free.

[fengguang.wu@intel.com: docbook problems spotted, now fixed]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index c4dd0bf..586c241 100644 (file)
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -161,47 +161,20 @@ static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
 static DEFINE_MUTEX(host_cmd_pool_mutex);
 
 /**
- * scsi_pool_alloc_command - internal function to get a fully allocated command
- * @pool:      slab pool to allocate the command from
- * @gfp_mask:  mask for the allocation
- *
- * Returns a fully allocated command (with the allied sense buffer) or
- * NULL on failure
- */
-static struct scsi_cmnd *
-scsi_pool_alloc_command(struct scsi_host_cmd_pool *pool, gfp_t gfp_mask)
-{
-       struct scsi_cmnd *cmd;
-
-       cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
-       if (!cmd)
-               return NULL;
-
-       cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab,
-                                            gfp_mask | pool->gfp_mask);
-       if (!cmd->sense_buffer) {
-               kmem_cache_free(pool->cmd_slab, cmd);
-               return NULL;
-       }
-
-       return cmd;
-}
-
-/**
- * scsi_pool_free_command - internal function to release a command
- * @pool:      slab pool to allocate the command from
+ * scsi_host_free_command - internal function to release a command
+ * @shost:     host to free the command for
  * @cmd:       command to release
  *
  * the command must previously have been allocated by
- * scsi_pool_alloc_command.
+ * scsi_host_alloc_command.
  */
 static void
-scsi_pool_free_command(struct scsi_host_cmd_pool *pool,
-                        struct scsi_cmnd *cmd)
+scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
 {
+       struct scsi_host_cmd_pool *pool = shost->cmd_pool;
+
        if (cmd->prot_sdb)
                kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
-
        kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
        kmem_cache_free(pool->cmd_slab, cmd);
 }
@@ -217,22 +190,32 @@ scsi_pool_free_command(struct scsi_host_cmd_pool *pool,
 static struct scsi_cmnd *
 scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)
 {
+       struct scsi_host_cmd_pool *pool = shost->cmd_pool;
        struct scsi_cmnd *cmd;
 
-       cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);
+       cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
        if (!cmd)
-               return NULL;
+               goto fail;
+
+       cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab,
+                                            gfp_mask | pool->gfp_mask);
+       if (!cmd->sense_buffer)
+               goto fail_free_cmd;
 
        if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
                cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
-
-               if (!cmd->prot_sdb) {
-                       scsi_pool_free_command(shost->cmd_pool, cmd);
-                       return NULL;
-               }
+               if (!cmd->prot_sdb)
+                       goto fail_free_sense;
        }
 
        return cmd;
+
+fail_free_sense:
+       kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
+fail_free_cmd:
+       kmem_cache_free(pool->cmd_slab, cmd);
+fail:
+       return NULL;
 }
 
 /**
@@ -320,7 +303,7 @@ void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
        }
 
        if (likely(cmd != NULL))
-               scsi_pool_free_command(shost->cmd_pool, cmd);
+               scsi_host_free_command(shost, cmd);
 }
 EXPORT_SYMBOL(__scsi_put_command);
 
@@ -456,7 +439,7 @@ void scsi_destroy_command_freelist(struct Scsi_Host *shost)
 
                cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
                list_del_init(&cmd->list);
-               scsi_pool_free_command(shost->cmd_pool, cmd);
+               scsi_host_free_command(shost, cmd);
        }
        shost->cmd_pool = NULL;
        scsi_put_host_cmd_pool(shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL);