From: Jens Axboe <axboe@fb.com>
Date: Fri, 9 Oct 2015 16:40:29 +0000 (-0600)
Subject: Merge branch 'for-4.4/core' into for-4.4/drivers
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=54ef2b96879334caf8803fdd93b4c556d709d6fd;p=openwrt%2Fstaging%2Fblogic.git

Merge branch 'for-4.4/core' into for-4.4/drivers

Signed-off-by: Jens Axboe <axboe@fb.com>
---

54ef2b96879334caf8803fdd93b4c556d709d6fd
diff --cc drivers/block/loop.c
index 23376084a5cb,674f800a3b57..423f4ca7d712
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@@ -445,90 -389,6 +445,89 @@@ static int lo_req_flush(struct loop_dev
  	return ret;
  }
  
 +static inline void handle_partial_read(struct loop_cmd *cmd, long bytes)
 +{
 +	if (bytes < 0 || (cmd->rq->cmd_flags & REQ_WRITE))
 +		return;
 +
 +	if (unlikely(bytes < blk_rq_bytes(cmd->rq))) {
 +		struct bio *bio = cmd->rq->bio;
 +
 +		bio_advance(bio, bytes);
 +		zero_fill_bio(bio);
 +	}
 +}
 +
 +static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
 +{
 +	struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb);
 +	struct request *rq = cmd->rq;
 +
 +	handle_partial_read(cmd, ret);
 +
 +	if (ret > 0)
 +		ret = 0;
 +	else if (ret < 0)
 +		ret = -EIO;
 +
- 	rq->errors = ret;
- 	blk_mq_complete_request(rq);
++	blk_mq_complete_request(rq, ret);
 +}
 +
 +static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
 +		     loff_t pos, bool rw)
 +{
 +	struct iov_iter iter;
 +	struct bio_vec *bvec;
 +	struct bio *bio = cmd->rq->bio;
 +	struct file *file = lo->lo_backing_file;
 +	int ret;
 +
 +	/* nomerge for loop request queue */
 +	WARN_ON(cmd->rq->bio != cmd->rq->biotail);
 +
 +	bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
 +	iov_iter_bvec(&iter, ITER_BVEC | rw, bvec,
 +		      bio_segments(bio), blk_rq_bytes(cmd->rq));
 +
 +	cmd->iocb.ki_pos = pos;
 +	cmd->iocb.ki_filp = file;
 +	cmd->iocb.ki_complete = lo_rw_aio_complete;
 +	cmd->iocb.ki_flags = IOCB_DIRECT;
 +
 +	if (rw == WRITE)
 +		ret = file->f_op->write_iter(&cmd->iocb, &iter);
 +	else
 +		ret = file->f_op->read_iter(&cmd->iocb, &iter);
 +
 +	if (ret != -EIOCBQUEUED)
 +		cmd->iocb.ki_complete(&cmd->iocb, ret, 0);
 +	return 0;
 +}
 +
 +
 +static inline int lo_rw_simple(struct loop_device *lo,
 +		struct request *rq, loff_t pos, bool rw)
 +{
 +	struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq);
 +
 +	if (cmd->use_aio)
 +		return lo_rw_aio(lo, cmd, pos, rw);
 +
 +	/*
 +	 * lo_write_simple and lo_read_simple should have been covered
 +	 * by io submit style function like lo_rw_aio(), one blocker
 +	 * is that lo_read_simple() need to call flush_dcache_page after
 +	 * the page is written from kernel, and it isn't easy to handle
 +	 * this in io submit style function which submits all segments
 +	 * of the req at one time. And direct read IO doesn't need to
 +	 * run flush_dcache_page().
 +	 */
 +	if (rw == WRITE)
 +		return lo_write_simple(lo, rq, pos);
 +	else
 +		return lo_read_simple(lo, rq, pos);
 +}
 +
  static int do_req_filebacked(struct loop_device *lo, struct request *rq)
  {
  	loff_t pos;
@@@ -1669,25 -1486,47 +1668,24 @@@ static void loop_handle_cmd(struct loop
  {
  	const bool write = cmd->rq->cmd_flags & REQ_WRITE;
  	struct loop_device *lo = cmd->rq->q->queuedata;
- 	int ret = -EIO;
+ 	int ret = 0;
  
- 	if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY))
+ 	if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) {
+ 		ret = -EIO;
  		goto failed;
+ 	}
  
  	ret = do_req_filebacked(lo, cmd->rq);
- 
   failed:
- 	if (ret)
- 		cmd->rq->errors = -EIO;
 -	blk_mq_complete_request(cmd->rq, ret ? -EIO : 0);
 +	/* complete non-aio request */
 +	if (!cmd->use_aio || ret)
- 		blk_mq_complete_request(cmd->rq);
++		blk_mq_complete_request(cmd->rq, ret ? -EIO : 0);
  }
  
 -static void loop_queue_write_work(struct work_struct *work)
 -{
 -	struct loop_device *lo =
 -		container_of(work, struct loop_device, write_work);
 -	LIST_HEAD(cmd_list);
 -
 -	spin_lock_irq(&lo->lo_lock);
 - repeat:
 -	list_splice_init(&lo->write_cmd_head, &cmd_list);
 -	spin_unlock_irq(&lo->lo_lock);
 -
 -	while (!list_empty(&cmd_list)) {
 -		struct loop_cmd *cmd = list_first_entry(&cmd_list,
 -				struct loop_cmd, list);
 -		list_del_init(&cmd->list);
 -		loop_handle_cmd(cmd);
 -	}
 -
 -	spin_lock_irq(&lo->lo_lock);
 -	if (!list_empty(&lo->write_cmd_head))
 -		goto repeat;
 -	lo->write_started = false;
 -	spin_unlock_irq(&lo->lo_lock);
 -}
 -
 -static void loop_queue_read_work(struct work_struct *work)
 +static void loop_queue_work(struct kthread_work *work)
  {
  	struct loop_cmd *cmd =
 -		container_of(work, struct loop_cmd, read_work);
 +		container_of(work, struct loop_cmd, work);
  
  	loop_handle_cmd(cmd);
  }