From e507e30b803fb56d768ed9a597e7609b74d2db21 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Thu, 13 Mar 2008 11:16:33 -0500 Subject: [PATCH] [SCSI] consolidate command allocation in a single place Since the way we allocate commands with a separate sense buffer is getting complicated, we should isolate setup and teardown to a single routine so that if it gets even more complex, there's only one place in the code that needs to be altered. Signed-off-by: James Bottomley --- drivers/scsi/scsi.c | 82 +++++++++++++++++++++++++++------------------ 1 file changed, 50 insertions(+), 32 deletions(-) diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index c78b836f59dd..2cf9a625f227 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -165,6 +165,51 @@ 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_alloc(pool->cmd_slab, gfp_mask | pool->gfp_mask); + if (!cmd) + return NULL; + + memset(cmd, 0, sizeof(*cmd)); + + 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 + * @cmd: command to release + * + * the command must previously have been allocated by + * scsi_pool_alloc_command. + */ +static void +scsi_pool_free_command(struct scsi_host_cmd_pool *pool, + struct scsi_cmnd *cmd) +{ + kmem_cache_free(pool->sense_slab, cmd->sense_buffer); + kmem_cache_free(pool->cmd_slab, cmd); +} + /** * __scsi_get_command - Allocate a struct scsi_cmnd * @shost: host to transmit command @@ -178,20 +223,7 @@ struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) struct scsi_cmnd *cmd; unsigned char *buf; - cmd = kmem_cache_alloc(shost->cmd_pool->cmd_slab, - gfp_mask | shost->cmd_pool->gfp_mask); - - if (likely(cmd)) { - buf = kmem_cache_alloc(shost->cmd_pool->sense_slab, - gfp_mask | shost->cmd_pool->gfp_mask); - if (likely(buf)) { - memset(cmd, 0, sizeof(*cmd)); - cmd->sense_buffer = buf; - } else { - kmem_cache_free(shost->cmd_pool->cmd_slab, cmd); - cmd = NULL; - } - } + cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask); if (unlikely(!cmd)) { unsigned long flags; @@ -268,11 +300,8 @@ void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd, } spin_unlock_irqrestore(&shost->free_list_lock, flags); - if (likely(cmd != NULL)) { - kmem_cache_free(shost->cmd_pool->sense_slab, - cmd->sense_buffer); - kmem_cache_free(shost->cmd_pool->cmd_slab, cmd); - } + if (likely(cmd != NULL)) + scsi_pool_free_command(shost->cmd_pool, cmd); put_device(dev); } @@ -348,23 +377,14 @@ int scsi_setup_command_freelist(struct Scsi_Host *shost) /* * Get one backup command for this host. */ - cmd = kmem_cache_alloc(shost->cmd_pool->cmd_slab, - GFP_KERNEL | shost->cmd_pool->gfp_mask); + cmd = scsi_pool_alloc_command(shost->cmd_pool, GFP_KERNEL); if (!cmd) goto fail2; - cmd->sense_buffer = kmem_cache_alloc(shost->cmd_pool->sense_slab, - GFP_KERNEL | - shost->cmd_pool->gfp_mask); - if (!cmd->sense_buffer) - goto fail2; - list_add(&cmd->list, &shost->free_list); return 0; fail2: - if (cmd) - kmem_cache_free(shost->cmd_pool->cmd_slab, cmd); mutex_lock(&host_cmd_pool_mutex); if (!--pool->users) { kmem_cache_destroy(pool->cmd_slab); @@ -386,9 +406,7 @@ 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); - kmem_cache_free(shost->cmd_pool->sense_slab, - cmd->sense_buffer); - kmem_cache_free(shost->cmd_pool->cmd_slab, cmd); + scsi_pool_free_command(shost->cmd_pool, cmd); } mutex_lock(&host_cmd_pool_mutex); -- 2.20.1