From 4246a0b63bd8f56a1469b12eafeb875b1041a451 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 20 Jul 2015 15:29:37 +0200 Subject: block: add a bi_error field to struct bio Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe --- fs/buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 1cf7a53a0277..7a49bb84ecb5 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2957,14 +2957,14 @@ sector_t generic_block_bmap(struct address_space *mapping, sector_t block, } EXPORT_SYMBOL(generic_block_bmap); -static void end_bio_bh_io_sync(struct bio *bio, int err) +static void end_bio_bh_io_sync(struct bio *bio) { struct buffer_head *bh = bio->bi_private; if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags))) set_bit(BH_Quiet, &bh->b_state); - bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags)); + bh->b_end_io(bh, !bio->bi_error); bio_put(bio); } -- cgit v1.2.3 From b7c44ed9d2fc6b461378c65eaf144ccc80a47772 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 24 Jul 2015 12:37:59 -0600 Subject: block: manipulate bio->bi_flags through helpers Some places use helpers now, others don't. We only have the 'is set' helper, add helpers for setting and clearing flags too. It was a bit of a mess of atomic vs non-atomic access. With BIO_UPTODATE gone, we don't have any risk of concurrent access to the flags. So relax the restriction and don't make any of them atomic. The flags that do have serialization issues (reffed and chained), we already handle those separately. Signed-off-by: Jens Axboe --- fs/buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 7a49bb84ecb5..7887bb466368 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2961,7 +2961,7 @@ static void end_bio_bh_io_sync(struct bio *bio) { struct buffer_head *bh = bio->bi_private; - if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags))) + if (unlikely(bio_flagged(bio, BIO_QUIET))) set_bit(BH_Quiet, &bh->b_state); bh->b_end_io(bh, !bio->bi_error); -- cgit v1.2.3 From 6cf66b4caf9c71f64a5486cadbd71ab58d0d4307 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Mon, 22 Dec 2014 12:48:42 +0100 Subject: fs: use helper bio_add_page() instead of open coding on bi_io_vec Call pre-defined helper bio_add_page() instead of open coding for iterating through bi_io_vec[]. Doing that, it's possible to make some parts in filesystems and mm/page_io.c simpler than before. Acked-by: Dave Kleikamp Cc: Christoph Hellwig Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kent Overstreet [dpark: add more description in commit message] Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe --- fs/buffer.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 7887bb466368..82283abb2795 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3046,12 +3046,9 @@ static int submit_bh_wbc(int rw, struct buffer_head *bh, bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio->bi_bdev = bh->b_bdev; - bio->bi_io_vec[0].bv_page = bh->b_page; - bio->bi_io_vec[0].bv_len = bh->b_size; - bio->bi_io_vec[0].bv_offset = bh_offset(bh); - bio->bi_vcnt = 1; - bio->bi_iter.bi_size = bh->b_size; + bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh)); + BUG_ON(bio->bi_iter.bi_size != bh->b_size); bio->bi_end_io = end_bio_bh_io_sync; bio->bi_private = bh; -- cgit v1.2.3