Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933329AbbDXHZi (ORCPT ); Fri, 24 Apr 2015 03:25:38 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:34383 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754981AbbDXHZf (ORCPT ); Fri, 24 Apr 2015 03:25:35 -0400 Date: Fri, 24 Apr 2015 00:25:34 -0700 From: Christoph Hellwig To: Ming Lin Cc: linux-kernel@vger.kernel.org, Christoph Hellwig , Kent Overstreet , Jens Axboe , Dongsu Park , Al Viro , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v3 3/4] fs: make _submit_bh consistent with generic bio chaining Message-ID: <20150424072534.GC8648@infradead.org> References: <1429830275-6792-1-git-send-email-mlin@kernel.org> <1429830275-6792-4-git-send-email-mlin@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1429830275-6792-4-git-send-email-mlin@kernel.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5319 Lines: 162 On Thu, Apr 23, 2015 at 04:04:34PM -0700, Ming Lin wrote: > From: Kent Overstreet > > Make _submit_bh() handle refcounting by increasing bio->bi_remaining, > followed by bio_endio(). Since bio chaining was introduced with > 196d38bccfcf ("block: Generic bio chaining"), refcounting should be > done on bi_remaining instead of ancient bio_cnt. Doing that, calling > convention can be consistent with the immutable biovecs API. I think this and the copy & paste version in nilfs2 can just go away. Since the big barrier to flush rewrite we will never fail FUA and FLUSH requests with BIO_EOPNOTSUPP. That error is just left for DISCARD adn WRITE_SAME. So something like the untested patch below should take care of this: diff --git a/block/bounce.c b/block/bounce.c index ab21ba2..4bac725 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -128,9 +128,6 @@ static void bounce_end_io(struct bio *bio, mempool_t *pool, int err) struct bio_vec *bvec, *org_vec; int i; - if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags)) - set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags); - /* * free up bounce indirect pages used */ diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 639f266..e8d7670 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3225,11 +3225,8 @@ static int write_dev_supers(struct btrfs_device *device, */ static void btrfs_end_empty_barrier(struct bio *bio, int err) { - if (err) { - if (err == -EOPNOTSUPP) - set_bit(BIO_EOPNOTSUPP, &bio->bi_flags); + if (err) clear_bit(BIO_UPTODATE, &bio->bi_flags); - } if (bio->bi_private) complete(bio->bi_private); bio_put(bio); @@ -3257,11 +3254,7 @@ static int write_dev_flush(struct btrfs_device *device, int wait) wait_for_completion(&device->flush_wait); - if (bio_flagged(bio, BIO_EOPNOTSUPP)) { - printk_in_rcu("BTRFS: disabling barriers on dev %s\n", - rcu_str_deref(device->name)); - device->nobarriers = 1; - } else if (!bio_flagged(bio, BIO_UPTODATE)) { + if (!bio_flagged(bio, BIO_UPTODATE)) { ret = -EIO; btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_FLUSH_ERRS); diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index d688cfe..6a44bea 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2767,8 +2767,6 @@ static int __must_check submit_one_bio(int rw, struct bio *bio, else btrfsic_submit_bio(rw, bio); - if (bio_flagged(bio, BIO_EOPNOTSUPP)) - ret = -EOPNOTSUPP; bio_put(bio); return ret; } diff --git a/fs/buffer.c b/fs/buffer.c index c7a5602..efd85e0 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2938,10 +2938,6 @@ static void end_bio_bh_io_sync(struct bio *bio, int err) { struct buffer_head *bh = bio->bi_private; - if (err == -EOPNOTSUPP) { - set_bit(BIO_EOPNOTSUPP, &bio->bi_flags); - } - if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags))) set_bit(BH_Quiet, &bh->b_state); @@ -3041,13 +3037,7 @@ int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags) if (buffer_prio(bh)) rw |= REQ_PRIO; - bio_get(bio); submit_bio(rw, bio); - - if (bio_flagged(bio, BIO_EOPNOTSUPP)) - ret = -EOPNOTSUPP; - - bio_put(bio); return ret; } EXPORT_SYMBOL_GPL(_submit_bh); diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 5765f88..c5d81e8 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -359,7 +359,6 @@ void ext4_io_submit(struct ext4_io_submit *io) if (bio) { bio_get(io->io_bio); submit_bio(io->io_op, io->io_bio); - BUG_ON(bio_flagged(io->io_bio, BIO_EOPNOTSUPP)); bio_put(io->io_bio); } io->io_bio = NULL; diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c index dc3a9efd..42468e5 100644 --- a/fs/nilfs2/segbuf.c +++ b/fs/nilfs2/segbuf.c @@ -343,11 +343,6 @@ static void nilfs_end_bio_write(struct bio *bio, int err) const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); struct nilfs_segment_buffer *segbuf = bio->bi_private; - if (err == -EOPNOTSUPP) { - set_bit(BIO_EOPNOTSUPP, &bio->bi_flags); - /* to be detected by nilfs_segbuf_submit_bio() */ - } - if (!uptodate) atomic_inc(&segbuf->sb_err); @@ -374,15 +369,8 @@ static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf, bio->bi_end_io = nilfs_end_bio_write; bio->bi_private = segbuf; - bio_get(bio); submit_bio(mode, bio); segbuf->sb_nbio++; - if (bio_flagged(bio, BIO_EOPNOTSUPP)) { - bio_put(bio); - err = -EOPNOTSUPP; - goto failed; - } - bio_put(bio); wi->bio = NULL; wi->rest_blocks -= wi->end - wi->start; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index a1b25e3..809feb3 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -118,7 +118,6 @@ struct bio { #define BIO_CLONED 4 /* doesn't own data */ #define BIO_BOUNCED 5 /* bio is a bounce bio */ #define BIO_USER_MAPPED 6 /* contains user pages */ -#define BIO_EOPNOTSUPP 7 /* not supported */ #define BIO_NULL_MAPPED 8 /* contains invalid user pages */ #define BIO_QUIET 9 /* Make BIO Quiet */ #define BIO_SNAP_STABLE 10 /* bio data must be snapshotted during write */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/