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fs: move guard_bio_eod() after bio_set_op_attrs 

Commit 85a8ce62c2 ("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: 85a8ce62c2 ("block: add bio_truncate to fix guard_bio_eod")
Signed-off-by: Ming Lei <ming.lei@redhat.com>

Fold in kerneldoc and bio_op() change.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ming Lei 2020-01-05 09:41:14 +08:00 committed by Jens Axboe
parent 57415790f4
commit 83c9c54716
4 changed files with 17 additions and 7 deletions
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12
block/bio.c
View File

@ -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) {

8
fs/buffer.c
View File

@ -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);

2
fs/internal.h
View File

@ -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);

2
fs/mpage.c
View File

@ -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;
}