Commit 5bb23a68 authored by NeilBrown's avatar NeilBrown Committed by Jens Axboe
Browse files

Don't decrement bi_size in bio_endio 



The only caller of bio_endio that does not pass the full bi_size
is end_that_request_first.  Also, no ->bi_end_io method is really
interested in bi_size being decremented.

So move the decrement and related code into ll_rw_blk and merge it
with order_bio_endio to form req_bio_endio which does endio functionality
specific to request completion.

As some ->bi_end_io methods do check bi_size of 0, we set it thus for
now, but that will go in the next patch.

Signed-off-by: default avatarNeil Brown <neilb@suse.de>

### Diffstat output
 ./block/ll_rw_blk.c |   42 +++++++++++++++++++++++++++---------------
 ./fs/bio.c          |   23 +++++++++++------------
 2 files changed, 38 insertions(+), 27 deletions(-)

diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 9cc54d40

block/ll_rw_blk.c

+27 −15
Original line number Diff line number Diff line
@@ -527,13 +527,28 @@ int blk_do_ordered(struct request_queue *q, struct request **rqp) 
	return 1;

}



static int ordered_bio_endio(struct request *rq, struct bio *bio,

static void req_bio_endio(struct request *rq, struct bio *bio,

			  unsigned int nbytes, int error)

{

	struct request_queue *q = rq->q;



	if (&q->bar_rq != rq)

		return 0;

	if (&q->bar_rq != rq) {

		if (error)

			clear_bit(BIO_UPTODATE, &bio->bi_flags);

		else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))

			error = -EIO;



		if (unlikely(nbytes > bio->bi_size)) {

			printk("%s: want %u bytes done, only %u left\n",

			       __FUNCTION__, nbytes, bio->bi_size);

			nbytes = bio->bi_size;

		}



		bio->bi_size -= nbytes;

		bio->bi_sector += (nbytes >> 9);

		if (bio->bi_size == 0)

			bio_endio(bio, bio->bi_size, error);

	} else {



		/*

		 * Okay, this is the barrier request in progress, just
@@ -541,8 +556,7 @@ static int ordered_bio_endio(struct request *rq, struct bio *bio, 
		 */

		if (error && !q->orderr)

			q->orderr = error;



	return 1;

	}

}



/**
@@ -3388,8 +3402,7 @@ static int __end_that_request_first(struct request *req, int uptodate, 
		if (nr_bytes >= bio->bi_size) {

			req->bio = bio->bi_next;

			nbytes = bio->bi_size;

			if (!ordered_bio_endio(req, bio, nbytes, error))

				bio_endio(bio, nbytes, error);

			req_bio_endio(req, bio, nbytes, error);

			next_idx = 0;

			bio_nbytes = 0;

		} else {
@@ -3444,8 +3457,7 @@ static int __end_that_request_first(struct request *req, int uptodate, 
	 * if the request wasn't completed, update state

	 */

	if (bio_nbytes) {

		if (!ordered_bio_endio(req, bio, bio_nbytes, error))

			bio_endio(bio, bio_nbytes, error);

		req_bio_endio(req, bio, bio_nbytes, error);

		bio->bi_idx += next_idx;

		bio_iovec(bio)->bv_offset += nr_bytes;

		bio_iovec(bio)->bv_len -= nr_bytes;

fs/bio.c

+11 −12
Original line number Diff line number Diff line
@@ -1006,13 +1006,14 @@ void bio_check_pages_dirty(struct bio *bio) 
 * @error:	error, if any

 *

 * Description:

 *   bio_endio() will end I/O on @bytes_done number of bytes. This may be

 *   just a partial part of the bio, or it may be the whole bio. bio_endio()

 *   is the preferred way to end I/O on a bio, it takes care of decrementing

 *   bi_size and clearing BIO_UPTODATE on error. @error is 0 on success, and

 *   and one of the established -Exxxx (-EIO, for instance) error values in

 *   case something went wrong. Noone should call bi_end_io() directly on

 *   a bio unless they own it and thus know that it has an end_io function.

 *   bio_endio() will end I/O on @bytes_done number of bytes. This

 *   must always be the whole (remaining) bio. bio_endio() is the

 *   preferred way to end I/O on a bio, it takes care of clearing

 *   BIO_UPTODATE on error. @error is 0 on success, and and one of the

 *   established -Exxxx (-EIO, for instance) error values in case

 *   something went wrong. Noone should call bi_end_io() directly on a

 *   bio unless they own it and thus know that it has an end_io

 *   function.

 **/

void bio_endio(struct bio *bio, unsigned int bytes_done, int error)

{
@@ -1021,16 +1022,14 @@ void bio_endio(struct bio *bio, unsigned int bytes_done, int error) 
	else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))

		error = -EIO;



	if (unlikely(bytes_done > bio->bi_size)) {

	if (unlikely(bytes_done != bio->bi_size)) {

		printk("%s: want %u bytes done, only %u left\n", __FUNCTION__,

						bytes_done, bio->bi_size);

		bytes_done = bio->bi_size;

	}



	bio->bi_size -= bytes_done;

	bio->bi_sector += (bytes_done >> 9);



	if (bio->bi_size && bio->bi_end_io)

	bio->bi_size = 0; /* expected by some callees - will be removed */

	if (bio->bi_end_io)

		bio->bi_end_io(bio, bytes_done, error);

}

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