[PATCH 8/9] scsi: simplify command allocation and freeing a bit

Christoph Hellwig
2014-02-20T22:23:59Z

[-- Attachment #1: 0008-scsi-simplify-command-allocation-and-freeing-a-bit.patch --]
[-- Type: text/plain, Size: 3815 bytes --]

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.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
drivers/scsi/scsi.c | 67 +++++++++++++++++++--------------------------------
1 file changed, 25 insertions(+), 42 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index a1ac75d..a94a486 100644
--- 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
+ * @host: 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;
}

/**
@@ -321,7 +304,7 @@ 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);

@@ -457,7 +440,7 @@ 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);
--
1.7.10.4