/* Do not call reset on error if we just did a reset within 15 sec. */
#define MIN_RESET_PERIOD (15*HZ)
-/*
- * Macro to determine the size of SCSI command. This macro takes vendor
- * unique commands into account. SCSI commands in groups 6 and 7 are
- * vendor unique and we will depend upon the command length being
- * supplied correctly in cmd_len.
- */
-#define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \
- COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len)
-
/*
* Note - the initial logging level can be set here to log events at boot time.
* After the system is up, you may enable logging via the /proc interface.
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
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;
}
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);
}
}
EXPORT_SYMBOL(scsi_put_command);
-/**
- * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
- * @shost: host to allocate the freelist for.
- *
- * Description: The command freelist protects against system-wide out of memory
- * deadlock by preallocating one SCSI command structure for each host, so the
- * system can always write to a swap file on a device associated with that host.
- *
- * Returns: Nothing.
- */
-int scsi_setup_command_freelist(struct Scsi_Host *shost)
+static struct scsi_host_cmd_pool *scsi_get_host_cmd_pool(gfp_t gfp_mask)
{
- struct scsi_host_cmd_pool *pool;
- struct scsi_cmnd *cmd;
-
- spin_lock_init(&shost->free_list_lock);
- INIT_LIST_HEAD(&shost->free_list);
-
+ struct scsi_host_cmd_pool *retval = NULL, *pool;
/*
* Select a command slab for this host and create it if not
* yet existent.
*/
mutex_lock(&host_cmd_pool_mutex);
- pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool);
+ pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool :
+ &scsi_cmd_pool;
if (!pool->users) {
pool->cmd_slab = kmem_cache_create(pool->cmd_name,
sizeof(struct scsi_cmnd), 0,
}
pool->users++;
- shost->cmd_pool = pool;
+ retval = pool;
+ fail:
mutex_unlock(&host_cmd_pool_mutex);
+ return retval;
+}
+
+static void scsi_put_host_cmd_pool(gfp_t gfp_mask)
+{
+ struct scsi_host_cmd_pool *pool;
+ mutex_lock(&host_cmd_pool_mutex);
+ pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool :
+ &scsi_cmd_pool;
/*
- * Get one backup command for this host.
+ * This may happen if a driver has a mismatched get and put
+ * of the command pool; the driver should be implicated in
+ * the stack trace
*/
- cmd = kmem_cache_alloc(shost->cmd_pool->cmd_slab,
- GFP_KERNEL | shost->cmd_pool->gfp_mask);
- 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;
+ BUG_ON(pool->users == 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);
kmem_cache_destroy(pool->sense_slab);
}
- fail:
mutex_unlock(&host_cmd_pool_mutex);
- return -ENOMEM;
+}
+
+/**
+ * scsi_allocate_command - get a fully allocated SCSI command
+ * @gfp_mask: allocation mask
+ *
+ * This function is for use outside of the normal host based pools.
+ * It allocates the relevant command and takes an additional reference
+ * on the pool it used. This function *must* be paired with
+ * scsi_free_command which also has the identical mask, otherwise the
+ * free pool counts will eventually go wrong and you'll trigger a bug.
+ *
+ * This function should *only* be used by drivers that need a static
+ * command allocation at start of day for internal functions.
+ */
+struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask)
+{
+ struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask);
+
+ if (!pool)
+ return NULL;
+
+ return scsi_pool_alloc_command(pool, gfp_mask);
+}
+EXPORT_SYMBOL(scsi_allocate_command);
+
+/**
+ * scsi_free_command - free a command allocated by scsi_allocate_command
+ * @gfp_mask: mask used in the original allocation
+ * @cmd: command to free
+ *
+ * Note: using the original allocation mask is vital because that's
+ * what determines which command pool we use to free the command. Any
+ * mismatch will cause the system to BUG eventually.
+ */
+void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd)
+{
+ struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask);
+
+ /*
+ * this could trigger if the mask to scsi_allocate_command
+ * doesn't match this mask. Otherwise we're guaranteed that this
+ * succeeds because scsi_allocate_command must have taken a reference
+ * on the pool
+ */
+ BUG_ON(!pool);
+
+ scsi_pool_free_command(pool, cmd);
+ /*
+ * scsi_put_host_cmd_pool is called twice; once to release the
+ * reference we took above, and once to release the reference
+ * originally taken by scsi_allocate_command
+ */
+ scsi_put_host_cmd_pool(gfp_mask);
+ scsi_put_host_cmd_pool(gfp_mask);
+}
+EXPORT_SYMBOL(scsi_free_command);
+
+/**
+ * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
+ * @shost: host to allocate the freelist for.
+ *
+ * Description: The command freelist protects against system-wide out of memory
+ * deadlock by preallocating one SCSI command structure for each host, so the
+ * system can always write to a swap file on a device associated with that host.
+ *
+ * Returns: Nothing.
+ */
+int scsi_setup_command_freelist(struct Scsi_Host *shost)
+{
+ struct scsi_cmnd *cmd;
+ const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
+
+ spin_lock_init(&shost->free_list_lock);
+ INIT_LIST_HEAD(&shost->free_list);
+
+ shost->cmd_pool = scsi_get_host_cmd_pool(gfp_mask);
+
+ if (!shost->cmd_pool)
+ return -ENOMEM;
+
+ /*
+ * Get one backup command for this host.
+ */
+ cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);
+ if (!cmd) {
+ scsi_put_host_cmd_pool(gfp_mask);
+ shost->cmd_pool = NULL;
+ return -ENOMEM;
+ }
+ list_add(&cmd->list, &shost->free_list);
+ return 0;
}
/**
*/
void scsi_destroy_command_freelist(struct Scsi_Host *shost)
{
+ /*
+ * If cmd_pool is NULL the free list was not initialized, so
+ * do not attempt to release resources.
+ */
+ if (!shost->cmd_pool)
+ return;
+
while (!list_empty(&shost->free_list)) {
struct scsi_cmnd *cmd;
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);
- }
-
- mutex_lock(&host_cmd_pool_mutex);
- if (!--shost->cmd_pool->users) {
- kmem_cache_destroy(shost->cmd_pool->cmd_slab);
- kmem_cache_destroy(shost->cmd_pool->sense_slab);
+ scsi_pool_free_command(shost->cmd_pool, cmd);
}
- mutex_unlock(&host_cmd_pool_mutex);
+ shost->cmd_pool = NULL;
+ scsi_put_host_cmd_pool(shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL);
}
#ifdef CONFIG_SCSI_LOGGING
* Before we queue this command, check if the command
* length exceeds what the host adapter can handle.
*/
- if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) {
+ if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
SCSI_LOG_MLQUEUE(3,
- printk("queuecommand : command too long.\n"));
+ printk("queuecommand : command too long. "
+ "cdb_size=%d host->max_cmd_len=%d\n",
+ cmd->cmd_len, cmd->device->host->max_cmd_len));
cmd->result = (DID_ABORT << 16);
scsi_done(cmd);
"Notifying upper driver of completion "
"(result %x)\n", cmd->result));
- good_bytes = scsi_bufflen(cmd) + cmd->request->extra_len;
+ good_bytes = scsi_bufflen(cmd);
if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
+ int old_good_bytes = good_bytes;
drv = scsi_cmd_to_driver(cmd);
if (drv->done)
good_bytes = drv->done(cmd);
+ /*
+ * USB may not give sense identifying bad sector and
+ * simply return a residue instead, so subtract off the
+ * residue if drv->done() error processing indicates no
+ * change to the completion length.
+ */
+ if (good_bytes == old_good_bytes)
+ good_bytes -= scsi_get_resid(cmd);
}
scsi_io_completion(cmd, good_bytes);
}
projects / linux-2.6-omap-h63xx.git / blobdiff