From 83c9c547168e8b914ea6398430473a4de68c52cc Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sun, 5 Jan 2020 09:41:14 +0800 Subject: [PATCH] fs: move guard_bio_eod() after bio_set_op_attrs Commit 85a8ce62c2ea ("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 Cc: linux-fsdevel@vger.kernel.org Fixes: 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod") Signed-off-by: Ming Lei Fold in kerneldoc and bio_op() change. Signed-off-by: Jens Axboe --- block/bio.c | 12 +++++++++++- fs/buffer.c | 8 ++++---- fs/internal.h | 2 +- fs/mpage.c | 2 +- 4 files changed, 17 insertions(+), 7 deletions(-) diff --git a/block/bio.c b/block/bio.c index 006bcc52a77e..94d697217887 100644 --- a/block/bio.c +++ b/block/bio.c @@ -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) { diff --git a/fs/buffer.c b/fs/buffer.c index e94a6619464c..18a87ec8a465 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -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); diff --git a/fs/internal.h b/fs/internal.h index 4a7da1df573d..e3fa69544b66 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -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); diff --git a/fs/mpage.c b/fs/mpage.c index a63620cdb73a..ccba3c4c4479 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -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; }