Commit cf655d95 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

block: loop: introduce lo_discard() and lo_req_flush() 



No behaviour change, just move the handling for REQ_DISCARD
and REQ_FLUSH in these two functions.

Signed-off-by: default avatarMing Lei <ming.lei@canonical.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 30112013

drivers/block/loop.c

+40 −33
Original line number Diff line number Diff line
@@ -417,54 +417,61 @@ lo_receive(struct loop_device *lo, struct request *rq, int bsize, loff_t pos) 
	return 0;

}



static int do_req_filebacked(struct loop_device *lo, struct request *rq)

static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos)

{

	loff_t pos;

	int ret;



	pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;



	if (rq->cmd_flags & REQ_WRITE) {

		struct file *file = lo->lo_backing_file;



		if (rq->cmd_flags & REQ_FLUSH) {

			ret = vfs_fsync(file, 0);

			if (unlikely(ret && ret != -EINVAL)) {

				ret = -EIO;

				goto out;

			}

		}



	/*

	 * We use punch hole to reclaim the free space used by the

	 * image a.k.a. discard. However we do not support discard if

	 * encryption is enabled, because it may give an attacker

	 * useful information.

	 */

		if (rq->cmd_flags & REQ_DISCARD) {

	struct file *file = lo->lo_backing_file;

	int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;

	int ret;



			if ((!file->f_op->fallocate) ||

			    lo->lo_encrypt_key_size) {

	if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) {

		ret = -EOPNOTSUPP;

		goto out;

	}

			ret = file->f_op->fallocate(file, mode, pos,

						    blk_rq_bytes(rq));

			if (unlikely(ret && ret != -EINVAL &&

				     ret != -EOPNOTSUPP))



	ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq));

	if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))

		ret = -EIO;

			goto out;

 out:

	return ret;

}



		ret = lo_send(lo, rq, pos);



		if ((rq->cmd_flags & REQ_FUA) && !ret) {

			ret = vfs_fsync(file, 0);

static int lo_req_flush(struct loop_device *lo, struct request *rq)

{

	struct file *file = lo->lo_backing_file;

	int ret = vfs_fsync(file, 0);

	if (unlikely(ret && ret != -EINVAL))

		ret = -EIO;



	return ret;

}



static int do_req_filebacked(struct loop_device *lo, struct request *rq)

{

	loff_t pos;

	int ret;



	pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;



	if (rq->cmd_flags & REQ_WRITE) {



		if (rq->cmd_flags & REQ_FLUSH)

			ret = lo_req_flush(lo, rq);



		if (rq->cmd_flags & REQ_DISCARD) {

			ret = lo_discard(lo, rq, pos);

			goto out;

		}



		ret = lo_send(lo, rq, pos);



		if ((rq->cmd_flags & REQ_FUA) && !ret)

			ret = lo_req_flush(lo, rq);

	} else

		ret = lo_receive(lo, rq, lo->lo_blocksize, pos);