[SCSI] add kmemcache for scsi_io_context
Add kmemcache of scsi io contexts.
In the future when we finalize on where these functions will live
we can add a mempool for it and do a bioset for out REQ_BLOCK_PC
bios. This is needed becuase the dm-multipath handlers will
want to use the scsi_exectute* functions for failover and we cannot
have them and the bio device allocating from the same mempool.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 3e136bf..54a72f1 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -306,6 +306,8 @@
char sense[SCSI_SENSE_BUFFERSIZE];
};
+static kmem_cache_t *scsi_io_context_cache;
+
static void scsi_end_async(struct request *req)
{
struct scsi_io_context *sioc = req->end_io_data;
@@ -313,7 +315,7 @@
if (sioc->done)
sioc->done(sioc->data, sioc->sense, req->errors, req->data_len);
- kfree(sioc);
+ kmem_cache_free(scsi_io_context_cache, sioc);
__blk_put_request(req->q, req);
}
@@ -452,9 +454,10 @@
int err = 0;
int write = (data_direction == DMA_TO_DEVICE);
- sioc = kzalloc(sizeof(*sioc), gfp);
+ sioc = kmem_cache_alloc(scsi_io_context_cache, gfp);
if (!sioc)
return DRIVER_ERROR << 24;
+ memset(sioc, 0, sizeof(*sioc));
req = blk_get_request(sdev->request_queue, write, gfp);
if (!req)
@@ -1765,6 +1768,14 @@
{
int i;
+ scsi_io_context_cache = kmem_cache_create("scsi_io_context",
+ sizeof(struct scsi_io_context),
+ 0, 0, NULL, NULL);
+ if (!scsi_io_context_cache) {
+ printk(KERN_ERR "SCSI: can't init scsi io context cache\n");
+ return -ENOMEM;
+ }
+
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
int size = sgp->size * sizeof(struct scatterlist);
@@ -1792,6 +1803,8 @@
{
int i;
+ kmem_cache_destroy(scsi_io_context_cache);
+
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
mempool_destroy(sgp->pool);