Commit 83c9c547 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

fs: move guard_bio_eod() after bio_set_op_attrs 



Commit 85a8ce62 ("block: add bio_truncate to fix guard_bio_eod")
adds bio_truncate() for handling bio EOD. However, bio_truncate()
doesn't use the passed 'op' parameter from guard_bio_eod's callers.

So bio_trunacate() may retrieve wrong 'op', and zering pages may
not be done for READ bio.

Fixes this issue by moving guard_bio_eod() after bio_set_op_attrs()
in submit_bh_wbc() so that bio_truncate() can always retrieve correct
op info.

Meantime remove the 'op' parameter from guard_bio_eod() because it isn't
used any more.

Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: linux-fsdevel@vger.kernel.org
Fixes: 85a8ce62 ("block: add bio_truncate to fix guard_bio_eod")
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>

Fold in kerneldoc and bio_op() change.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 57415790

block/bio.c

+11 −1
Original line number Diff line number Diff line
@@ -538,6 +538,16 @@ void zero_fill_bio_iter(struct bio *bio, struct bvec_iter start) 
}

EXPORT_SYMBOL(zero_fill_bio_iter);



/**

 * bio_truncate - truncate the bio to small size of @new_size

 * @bio:	the bio to be truncated

 * @new_size:	new size for truncating the bio

 *

 * Description:

 *   Truncate the bio to new size of @new_size. If bio_op(bio) is

 *   REQ_OP_READ, zero the truncated part. This function should only

 *   be used for handling corner cases, such as bio eod.

 */

void bio_truncate(struct bio *bio, unsigned new_size)

{

	struct bio_vec bv;
@@ -548,7 +558,7 @@ void bio_truncate(struct bio *bio, unsigned new_size) 
	if (new_size >= bio->bi_iter.bi_size)

		return;



	if (bio_data_dir(bio) != READ)

	if (bio_op(bio) != REQ_OP_READ)

		goto exit;



	bio_for_each_segment(bv, bio, iter) {

fs/buffer.c

+4 −4
Original line number Diff line number Diff line
@@ -3031,7 +3031,7 @@ static void end_bio_bh_io_sync(struct bio *bio) 
 * errors, this only handles the "we need to be able to

 * do IO at the final sector" case.

 */

void guard_bio_eod(int op, struct bio *bio)

void guard_bio_eod(struct bio *bio)

{

	sector_t maxsector;

	struct hd_struct *part;
@@ -3095,15 +3095,15 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh, 
	bio->bi_end_io = end_bio_bh_io_sync;

	bio->bi_private = bh;



	/* Take care of bh's that straddle the end of the device */

	guard_bio_eod(op, bio);



	if (buffer_meta(bh))

		op_flags |= REQ_META;

	if (buffer_prio(bh))

		op_flags |= REQ_PRIO;

	bio_set_op_attrs(bio, op, op_flags);



	/* Take care of bh's that straddle the end of the device */

	guard_bio_eod(bio);



	if (wbc) {

		wbc_init_bio(wbc, bio);

		wbc_account_cgroup_owner(wbc, bh->b_page, bh->b_size);

fs/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ static inline int __sync_blockdev(struct block_device *bdev, int wait) 
/*

 * buffer.c

 */

extern void guard_bio_eod(int rw, struct bio *bio);

extern void guard_bio_eod(struct bio *bio);

extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,

		get_block_t *get_block, struct iomap *iomap);

fs/mpage.c

+1 −1
Original line number Diff line number Diff line
@@ -62,7 +62,7 @@ static struct bio *mpage_bio_submit(int op, int op_flags, struct bio *bio) 
{

	bio->bi_end_io = mpage_end_io;

	bio_set_op_attrs(bio, op, op_flags);

	guard_bio_eod(op, bio);

	guard_bio_eod(bio);

	submit_bio(bio);

	return NULL;

}

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