Commit c853a578 authored by Goldwyn Rodrigues's avatar Goldwyn Rodrigues Committed by David Sterba
Browse files

btrfs: allocate btrfs_ioctl_defrag_range_args on stack 



Instead of using kmalloc() to allocate btrfs_ioctl_defrag_range_args,
allocate btrfs_ioctl_defrag_range_args on stack, the size is reasonably
small and ioctls are called in process context.

sizeof(btrfs_ioctl_defrag_range_args) = 48

Reviewed-by: default avatarAnand Jain <anand.jain@oracle.com>
Signed-off-by: default avatarGoldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 0afb603a

fs/btrfs/ioctl.c

+7 −16
Original line number Diff line number Diff line
@@ -3096,7 +3096,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) 
{

	struct inode *inode = file_inode(file);

	struct btrfs_root *root = BTRFS_I(inode)->root;

	struct btrfs_ioctl_defrag_range_args *range;

	struct btrfs_ioctl_defrag_range_args range = {0};

	int ret;



	ret = mnt_want_write_file(file);
@@ -3134,33 +3134,24 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) 
			goto out;

		}



		range = kzalloc(sizeof(*range), GFP_KERNEL);

		if (!range) {

			ret = -ENOMEM;

			goto out;

		}



		if (argp) {

			if (copy_from_user(range, argp,

					   sizeof(*range))) {

			if (copy_from_user(&range, argp, sizeof(range))) {

				ret = -EFAULT;

				kfree(range);

				goto out;

			}

			/* compression requires us to start the IO */

			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {

				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;

				range->extent_thresh = (u32)-1;

			if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {

				range.flags |= BTRFS_DEFRAG_RANGE_START_IO;

				range.extent_thresh = (u32)-1;

			}

		} else {

			/* the rest are all set to zero by kzalloc */

			range->len = (u64)-1;

			range.len = (u64)-1;

		}

		ret = btrfs_defrag_file(file_inode(file), file,

					range, BTRFS_OLDEST_GENERATION, 0);

					&range, BTRFS_OLDEST_GENERATION, 0);

		if (ret > 0)

			ret = 0;

		kfree(range);

		break;

	default:

		ret = -EINVAL;