Staging: hv: storvsc: Use mempools to allocate struct storvsc_cmd_request

We intend to use the storage driver to manage the root device.
To avoid deadlocks, use mempools to allocate struct storvsc_cmd_request.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index ae8c33e7849c1919233a559b1665290f523bc356..6a255e97721941b5992080bd058b2ceee0da5d71 100644 (file)
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -32,6 +32,7 @@
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/hyperv.h>
+#include <linux/mempool.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_host.h>
@@ -42,6 +43,7 @@
 #include <scsi/scsi_dbg.h>
 
 
+#define STORVSC_MIN_BUF_NR                             64
 #define STORVSC_RING_BUFFER_SIZE                       (20*PAGE_SIZE)
 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
 
@@ -287,6 +289,7 @@ struct storvsc_device {
 struct hv_host_device {
        struct hv_device *dev;
        struct kmem_cache *request_pool;
+       mempool_t *request_mempool;
        unsigned int port;
        unsigned char path;
        unsigned char target;
@@ -974,8 +977,10 @@ static int storvsc_remove(struct hv_device *dev)
 
        storvsc_dev_remove(dev);
        if (host_dev->request_pool) {
+               mempool_destroy(host_dev->request_mempool);
                kmem_cache_destroy(host_dev->request_pool);
                host_dev->request_pool = NULL;
+               host_dev->request_mempool = NULL;
        }
        return 0;
 }
@@ -1120,7 +1125,7 @@ static void storvsc_command_completion(struct hv_storvsc_request *request)
 
        scsi_done_fn(scmnd);
 
-       kmem_cache_free(host_dev->request_pool, cmd_request);
+       mempool_free(cmd_request, host_dev->request_mempool);
 }
 
 static bool storvsc_check_scsi_cmd(struct scsi_cmnd *scmnd)
@@ -1176,12 +1181,13 @@ static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
 
        request_size = sizeof(struct storvsc_cmd_request);
 
-       cmd_request = kmem_cache_zalloc(host_dev->request_pool,
+       cmd_request = mempool_alloc(host_dev->request_mempool,
                                       GFP_ATOMIC);
        if (!cmd_request) {
                scmnd->scsi_done = NULL;
                return SCSI_MLQUEUE_DEVICE_BUSY;
        }
+       memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
 
        /* Setup the cmd request */
        cmd_request->bounce_sgl_count = 0;
@@ -1235,8 +1241,8 @@ static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
                        if (!cmd_request->bounce_sgl) {
                                scmnd->scsi_done = NULL;
                                scmnd->host_scribble = NULL;
-                               kmem_cache_free(host_dev->request_pool,
-                                               cmd_request);
+                               mempool_free(cmd_request,
+                                               host_dev->request_mempool);
 
                                return SCSI_MLQUEUE_HOST_BUSY;
                        }
@@ -1278,7 +1284,7 @@ retry_request:
                        destroy_bounce_buffer(cmd_request->bounce_sgl,
                                        cmd_request->bounce_sgl_count);
 
-               kmem_cache_free(host_dev->request_pool, cmd_request);
+               mempool_free(cmd_request, host_dev->request_mempool);
 
                scmnd->scsi_done = NULL;
                scmnd->host_scribble = NULL;
@@ -1348,6 +1354,7 @@ static int storvsc_probe(struct hv_device *device,
                        const struct hv_vmbus_device_id *dev_id)
 {
        int ret;
+       int number = STORVSC_MIN_BUF_NR;
        struct Scsi_Host *host;
        struct hv_host_device *host_dev;
        bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
@@ -1376,8 +1383,19 @@ static int storvsc_probe(struct hv_device *device,
                return -ENOMEM;
        }
 
+       host_dev->request_mempool = mempool_create(number, mempool_alloc_slab,
+                                               mempool_free_slab,
+                                               host_dev->request_pool);
+
+       if (!host_dev->request_mempool) {
+               kmem_cache_destroy(host_dev->request_pool);
+               scsi_host_put(host);
+               return -ENOMEM;
+       }
+
        stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
        if (!stor_device) {
+               mempool_destroy(host_dev->request_mempool);
                kmem_cache_destroy(host_dev->request_pool);
                scsi_host_put(host);
                return -ENOMEM;
@@ -1392,6 +1410,7 @@ static int storvsc_probe(struct hv_device *device,
        stor_device->port_number = host->host_no;
        ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
        if (ret) {
+               mempool_destroy(host_dev->request_mempool);
                kmem_cache_destroy(host_dev->request_pool);
                scsi_host_put(host);
                kfree(stor_device);
@@ -1431,6 +1450,7 @@ static int storvsc_probe(struct hv_device *device,
 
 err_out:
        storvsc_dev_remove(device);
+       mempool_destroy(host_dev->request_mempool);
        kmem_cache_destroy(host_dev->request_pool);
        scsi_host_put(host);
        return -ENODEV;