[PATCH 1/2] block: remove BIO_EOPNOTSUPP

[PATCH 1/2] block: remove BIO_EOPNOTSUPP

[Christoph Hellwig]

Since the big barrier rewrite/removal in 2007 we never fail FLUSH or
FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag
to help propagating those to the buffer_head layer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bounce.c            |  3 ---
 fs/btrfs/disk-io.c        | 11 ++---------
 fs/btrfs/extent_io.c      |  2 --
 fs/buffer.c               | 10 ----------
 fs/ext4/page-io.c         |  1 -
 fs/nilfs2/segbuf.c        | 12 ------------
 include/linux/blk_types.h |  1 -
 7 files changed, 2 insertions(+), 38 deletions(-)

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 4649842..36f0eaa 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -343,7 +343,6 @@ 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 992ef58..c2ee937 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 */
-- 
1.9.1

[PATCH 2/2] block: remove unused BIO_RW_BLOCK and BIO_EOF flags

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c          | 2 --
 include/linux/blk_types.h | 2 --
 2 files changed, 4 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 57da507..4085265 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1716,8 +1716,6 @@ static void handle_bad_sector(struct bio *bio)
 			bio->bi_rw,
 			(unsigned long long)bio_end_sector(bio),
 			(long long)(i_size_read(bio->bi_bdev->bd_inode) >> 9));
-
-	set_bit(BIO_EOF, &bio->bi_flags);
 }
 
 #ifdef CONFIG_FAIL_MAKE_REQUEST
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index c2ee937..b0a5bff 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -112,8 +112,6 @@ struct bio {
  * bio flags
  */
 #define BIO_UPTODATE	0	/* ok after I/O completion */
-#define BIO_RW_BLOCK	1	/* RW_AHEAD set, and read/write would block */
-#define BIO_EOF		2	/* out-out-bounds error */
 #define BIO_SEG_VALID	3	/* bi_phys_segments valid */
 #define BIO_CLONED	4	/* doesn't own data */
 #define BIO_BOUNCED	5	/* bio is a bounce bio */
-- 
1.9.1

Re: [PATCH 2/2] block: remove unused BIO_RW_BLOCK and BIO_EOF flags

[Jeff Moyer]

Christoph Hellwig <hch@lst.de> writes:

> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
> index c2ee937..b0a5bff 100644
> --- a/include/linux/blk_types.h
> +++ b/include/linux/blk_types.h
> @@ -112,8 +112,6 @@ struct bio {
>   * bio flags
>   */
>  #define BIO_UPTODATE	0	/* ok after I/O completion */
> -#define BIO_RW_BLOCK	1	/* RW_AHEAD set, and read/write would block */
> -#define BIO_EOF		2	/* out-out-bounds error */
>  #define BIO_SEG_VALID	3	/* bi_phys_segments valid */
>  #define BIO_CLONED	4	/* doesn't own data */
>  #define BIO_BOUNCED	5	/* bio is a bounce bio */

Any particular reason you elected to leave a hole in the numbering?  I
don't have a preference either way, but I don't think there's any harm
in compressing it.

-Jeff

Re: [PATCH 2/2] block: remove unused BIO_RW_BLOCK and BIO_EOF flags

[Christoph Hellwig]

On Fri, Apr 24, 2015 at 03:47:37PM -0400, Jeff Moyer wrote:
> Any particular reason you elected to leave a hole in the numbering?  I
> don't have a preference either way, but I don't think there's any harm
> in compressing it.

This was the simplest way to do it and I'm a lazy bastard.

Re: [PATCH 1/2] block: remove BIO_EOPNOTSUPP

[Jeff Moyer]

Christoph Hellwig <hch@lst.de> writes:

> Since the big barrier rewrite/removal in 2007 we never fail FLUSH or
> FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag
> to help propagating those to the buffer_head layer.

I had a look through the kernel, checking for places where maybe we were
relying on an EOPNOTSUPP from REQ_DISCARD, just to ensure you weren't
pulling out an error path that could still be used.  I think everything
checks out.

> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
> index 992ef58..c2ee937 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 */

Should we leave a hole in the numbering scheme?

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>

Re: [PATCH 2/2] block: remove unused BIO_RW_BLOCK and BIO_EOF flags

[Jeff Moyer]

Christoph Hellwig <hch@lst.de> writes:

> On Fri, Apr 24, 2015 at 03:47:37PM -0400, Jeff Moyer wrote:
>> Any particular reason you elected to leave a hole in the numbering?  I
>> don't have a preference either way, but I don't think there's any harm
>> in compressing it.
>
> This was the simplest way to do it and I'm a lazy bastard.

Heh.  /me looks at hch's contributions... You have a rather broad
definition of lazy.  :-)

Re: [PATCH 1/2] block: remove BIO_EOPNOTSUPP

[Tejun Heo]

On Fri, Apr 24, 2015 at 09:41:01PM +0200, Christoph Hellwig wrote:
> Since the big barrier rewrite/removal in 2007 we never fail FLUSH or
> FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag
> to help propagating those to the buffer_head layer.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun

Re: [PATCH 2/2] block: remove unused BIO_RW_BLOCK and BIO_EOF flags

[Tejun Heo]

On Fri, Apr 24, 2015 at 09:41:02PM +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun

Re: [PATCH 1/2] block: remove BIO_EOPNOTSUPP

[Christoph Hellwig]

Jens, do these two patche look fine to you?

Re: [PATCH 1/2] block: remove BIO_EOPNOTSUPP

[Jens Axboe]

On 05/19/2015 12:39 AM, Christoph Hellwig wrote:
> Jens, do these two patche look fine to you?
>
Yep, nice and simple, applied both.

-- 
Jens Axboe