[dm-devel] [PATCH 4/7] dm: use kvmalloc

[Mikulas Patocka]

Use the function kvmalloc to allocate ioctl parameters.

Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>

---
 drivers/md/dm-ioctl.c         |   26 +++++---------------------
 drivers/md/dm-table.c         |   37 +++++++++++++++++++++++++++++++++++++
 include/linux/device-mapper.h |    2 ++
 3 files changed, 44 insertions(+), 21 deletions(-)

Index: linux-4.1/drivers/md/dm-ioctl.c
===================================================================
--- linux-4.1.orig/drivers/md/dm-ioctl.c	2015-07-02 19:21:15.000000000 +0200
+++ linux-4.1/drivers/md/dm-ioctl.c	2015-07-02 19:21:21.000000000 +0200
@@ -1676,12 +1676,8 @@ static void free_params(struct dm_ioctl 
 	if (param_flags & DM_WIPE_BUFFER)
 		memset(param, 0, param_size);
 
-	if (param_flags & DM_PARAMS_ALLOC) {
-		if (is_vmalloc_addr(param))
-			vfree(param);
-		else
-			kfree(param);
-	}
+	if (param_flags & DM_PARAMS_ALLOC)
+		kvfree(param);
 }
 
 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
@@ -1712,21 +1708,7 @@ static int copy_params(struct dm_ioctl _
 	 * Try to avoid low memory issues when a device is suspended.
 	 * Use kmalloc() rather than vmalloc() when we can.
 	 */
-	dmi = NULL;
-	if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
-		dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
-		if (dmi)
-			*param_flags |= DM_PARAMS_ALLOC;
-	}
-
-	if (!dmi) {
-		unsigned noio_flag;
-		noio_flag = memalloc_noio_save();
-		dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL);
-		memalloc_noio_restore(noio_flag);
-		if (dmi)
-			*param_flags |= DM_PARAMS_ALLOC;
-	}
+	dmi = kvmalloc(param_kernel->data_size, GFP_NOIO);
 
 	if (!dmi) {
 		if (secure_data && clear_user(user, param_kernel->data_size))
@@ -1734,6 +1716,8 @@ static int copy_params(struct dm_ioctl _
 		return -ENOMEM;
 	}
 
+	*param_flags |= DM_PARAMS_ALLOC;
+
 	if (copy_from_user(dmi, user, param_kernel->data_size))
 		goto bad;