Commit e2c789ca authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Mike Snitzer
Browse files

dm: get rid of GFP_NOIO workarounds for __vmalloc and kvmalloc 



In the past, the function __vmalloc didn't respect the GFP flags - it
allocated memory with the provided gfp flags, but it allocated page tables
with GFP_KERNEL. This was fixed in commit 451769eb ("mm/vmalloc:
alloc GFP_NO{FS,IO} for vmalloc") so the memalloc_noio_{save,restore}
workaround is no longer needed.

The function kvmalloc didn't like flags different from GFP_KERNEL. This
was fixed in commit a421ef30 ("mm: allow !GFP_KERNEL allocations
for kvmalloc"), so kvmalloc can now be called with GFP_NOIO.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@kernel.org>
parent 3be16228

drivers/md/dm-bufio.c

+0 −17
Original line number Diff line number Diff line
@@ -1157,23 +1157,6 @@ static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask, 


	*data_mode = DATA_MODE_VMALLOC;



	/*

	 * __vmalloc allocates the data pages and auxiliary structures with

	 * gfp_flags that were specified, but pagetables are always allocated

	 * with GFP_KERNEL, no matter what was specified as gfp_mask.

	 *

	 * Consequently, we must set per-process flag PF_MEMALLOC_NOIO so that

	 * all allocations done by this process (including pagetables) are done

	 * as if GFP_NOIO was specified.

	 */

	if (gfp_mask & __GFP_NORETRY) {

		unsigned int noio_flag = memalloc_noio_save();

		void *ptr = __vmalloc(c->block_size, gfp_mask);



		memalloc_noio_restore(noio_flag);

		return ptr;

	}



	return __vmalloc(c->block_size, gfp_mask);

}

drivers/md/dm-ioctl.c

+1 −4
Original line number Diff line number Diff line
@@ -1932,7 +1932,6 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern 
	struct dm_ioctl *dmi;

	int secure_data;

	const size_t minimum_data_size = offsetof(struct dm_ioctl, data);

	unsigned int noio_flag;



	/* check_version() already copied version from userspace, avoid TOCTOU */

	if (copy_from_user((char *)param_kernel + sizeof(param_kernel->version),
@@ -1962,9 +1961,7 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern 
	 * Use kmalloc() rather than vmalloc() when we can.

	 */

	dmi = NULL;

	noio_flag = memalloc_noio_save();

	dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);

	memalloc_noio_restore(noio_flag);

	dmi = kvmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH);



	if (!dmi) {

		if (secure_data && clear_user(user, param_kernel->data_size))