mbox series

[RFC,00/34] block: introduce bio_new()

Message ID 20210128071133.60335-1-chaitanya.kulkarni@wdc.com
Headers show
Series block: introduce bio_new() | expand

Message

Chaitanya Kulkarni Jan. 28, 2021, 7:10 a.m. UTC 
Hi,

This is a *compile only RFC* which adds a generic helper to initialize
the various fields of the bio that is repeated all the places in
file-systems, block layer, and drivers.

The new helper allows callers to initialize non-optional members of bio
such as bdev, sector, op, opflags, max_bvecs and gfp_mask by
encapsulating new bio allocation with bio alloc with initialization
at one place.

The objective of this RFC is to only start a discussion, this it not 
completely tested at all.

-ck                         

Chaitanya Kulkarni (34):
  block: move common code into blk_next_bio()
  block: introduce and use bio_new
  drdb: use bio_new in drdb
  drdb: use bio_new() in submit_one_flush
  xen-blkback: use bio_new
  zram: use bio_new
  dm: use bio_new in dm-log-writes
  dm-zoned: use bio_new in get_mblock_slow
  dm-zoned: use bio_new in dmz_write_mblock
  dm-zoned: use bio_new in dmz_rdwr_block
  nvmet: use bio_new in nvmet_bdev_execute_rw
  scsi: target/iblock: use bio_new
  block: use bio_new in __blkdev_direct_IO
  fs/buffer: use bio_new in submit_bh_wbc
  fscrypt: use bio_new in fscrypt_zeroout_range
  fs/direct-io: use bio_new in dio_bio_alloc
  iomap: use bio_new in iomap_dio_zero
  iomap: use bio_new in iomap_dio_bio_actor
  fs/jfs/jfs_logmgr.c: use bio_new in lbmRead
  fs/jfs/jfs_logmgr.c: use bio_new in lbmStartIO
  fs/jfs/jfs_metapage.c: use bio_new in metapage_writepage
  fs/jfs/jfs_metapage.c: use bio_new in metapage_readpage
  fs/mpage.c: use bio_new mpage_alloc
  fs/nilfs: use bio_new nilfs_alloc_seg_bio
  ocfs/cluster: use bio_new in dm-log-writes
  xfs: use bio_new in xfs_rw_bdev
  xfs: use bio_new in xfs_buf_ioapply_map
  zonefs: use bio_new
  power/swap: use bio_new in hib_submit_io
  hfsplus: use bio_new in hfsplus_submit_bio()
  iomap: use bio_new in iomap_readpage_actor
  mm: use bio_new in __swap_writepage
  mm: use bio_new in swap_readpage
  mm: add swap_bio_new common bio helper

 block/blk-lib.c                     | 34 ++++++++++-------------------
 block/blk-zoned.c                   |  4 +---
 block/blk.h                         |  5 +++--
 drivers/block/drbd/drbd_receiver.c  | 12 +++++-----
 drivers/block/xen-blkback/blkback.c | 20 +++++++++++------
 drivers/block/zram/zram_drv.c       |  5 ++---
 drivers/md/dm-log-writes.c          | 30 +++++++++----------------
 drivers/md/dm-zoned-metadata.c      | 18 +++++----------
 drivers/nvme/target/io-cmd-bdev.c   |  9 +++-----
 drivers/target/target_core_iblock.c |  5 ++---
 fs/block_dev.c                      |  6 ++---
 fs/buffer.c                         | 16 ++++++--------
 fs/crypto/bio.c                     |  5 ++---
 fs/direct-io.c                      |  6 ++---
 fs/hfsplus/wrapper.c                |  5 +----
 fs/iomap/buffered-io.c              | 12 +++++-----
 fs/iomap/direct-io.c                | 11 ++++------
 fs/jfs/jfs_logmgr.c                 | 13 ++++-------
 fs/jfs/jfs_metapage.c               | 15 +++++--------
 fs/mpage.c                          | 18 +++++----------
 fs/nilfs2/segbuf.c                  | 10 ++-------
 fs/ocfs2/cluster/heartbeat.c        |  6 ++---
 fs/xfs/xfs_bio_io.c                 |  7 ++----
 fs/xfs/xfs_buf.c                    |  6 ++---
 fs/zonefs/super.c                   |  6 ++---
 include/linux/bio.h                 | 25 +++++++++++++++++++++
 kernel/power/swap.c                 |  7 +++---
 mm/page_io.c                        | 30 +++++++++++++------------
 28 files changed, 151 insertions(+), 195 deletions(-)

Comments

Damien Le Moal Jan. 28, 2021, 7:25 a.m. UTC | #1 
On 2021/01/28 16:15, Chaitanya Kulkarni wrote:
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> ---
>  fs/zonefs/super.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
> index ab68e27bb322..620d67965a22 100644
> --- a/fs/zonefs/super.c
> +++ b/fs/zonefs/super.c
> @@ -661,6 +661,7 @@ static const struct iomap_dio_ops zonefs_write_dio_ops = {
>  
>  static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from)
>  {
> +	unsigned int op = REQ_OP_ZONE_APPEND | REQ_SYNC | REQ_IDLE;

I do not see the point of adding this variable since it is used only for the
bio_new() call. Pass the op value directly.

>  	struct inode *inode = file_inode(iocb->ki_filp);
>  	struct zonefs_inode_info *zi = ZONEFS_I(inode);
>  	struct block_device *bdev = inode->i_sb->s_bdev;
> @@ -678,15 +679,12 @@ static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from)
>  	if (!nr_pages)
>  		return 0;
>  
> -	bio = bio_alloc(GFP_NOFS, nr_pages);
> +	bio = bio_new(bdev, zi->i_zsector, op, 0, GFP_NOFS, nr_pages);
>  	if (!bio)
>  		return -ENOMEM;
>  
> -	bio_set_dev(bio, bdev);
> -	bio->bi_iter.bi_sector = zi->i_zsector;
>  	bio->bi_write_hint = iocb->ki_hint;
>  	bio->bi_ioprio = iocb->ki_ioprio;
> -	bio->bi_opf = REQ_OP_ZONE_APPEND | REQ_SYNC | REQ_IDLE;
>  	if (iocb->ki_flags & IOCB_DSYNC)
>  		bio->bi_opf |= REQ_FUA;
>  
>
Rafael J. Wysocki Jan. 28, 2021, 10:21 a.m. UTC | #2 
On Thu, Jan 28, 2021 at 8:21 AM Chaitanya Kulkarni
<chaitanya.kulkarni@wdc.com> wrote:
>

Please explain in the changelog why making this change is a good idea.

> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> ---
>  kernel/power/swap.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/power/swap.c b/kernel/power/swap.c
> index c73f2e295167..e92e36c053a6 100644
> --- a/kernel/power/swap.c
> +++ b/kernel/power/swap.c
> @@ -271,13 +271,12 @@ static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
>                 struct hib_bio_batch *hb)
>  {
>         struct page *page = virt_to_page(addr);
> +       sector_t sect = page_off * (PAGE_SIZE >> 9);
>         struct bio *bio;
>         int error = 0;
>
> -       bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1);
> -       bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
> -       bio_set_dev(bio, hib_resume_bdev);
> -       bio_set_op_attrs(bio, op, op_flags);
> +       bio = bio_new(hib_resume_bdev, sect, op, op_flags, 1,
> +                     GFP_NOIO | __GFP_HIGH);
>
>         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
>                 pr_err("Adding page to bio failed at %llu\n",
> --
> 2.22.1
>
Dave Kleikamp Jan. 28, 2021, 12:43 p.m. UTC | #3 
You probably don't need 4 patches to fs/jfs/. These can be combined into 
a single patch.

Dave

On 1/28/21 1:11 AM, Chaitanya Kulkarni wrote:
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> ---
>   fs/jfs/jfs_logmgr.c | 7 ++-----
>   1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
> index 9330eff210e0..4481f3e33a3f 100644
> --- a/fs/jfs/jfs_logmgr.c
> +++ b/fs/jfs/jfs_logmgr.c
> @@ -1979,17 +1979,14 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
>   
>   	bp->l_flag |= lbmREAD;
>   
> -	bio = bio_alloc(GFP_NOFS, 1);
> -
> -	bio->bi_iter.bi_sector = bp->l_blkno << (log->l2bsize - 9);
> -	bio_set_dev(bio, log->bdev);
> +	bio = bio_new(log->bdev, bp->l_blkno << (log->l2bsize - 9),
> +			REQ_OP_READ, 0, 1, GFP_NOFS);
>   
>   	bio_add_page(bio, bp->l_page, LOGPSIZE, bp->l_offset);
>   	BUG_ON(bio->bi_iter.bi_size != LOGPSIZE);
>   
>   	bio->bi_end_io = lbmIODone;
>   	bio->bi_private = bp;
> -	bio->bi_opf = REQ_OP_READ;
>   	/*check if journaling to disk has been disabled*/
>   	if (log->no_integrity) {
>   		bio->bi_iter.bi_size = 0;
>
Matthew Wilcox Jan. 28, 2021, 4:47 p.m. UTC | #4 
FYI your email is completely unreadable to those not using html.
I can't tell what you wrote and what Damien wrote.

On Thu, Jan 28, 2021 at 08:33:10AM +0000, Chaitanya Kulkarni wrote:
> On 1/27/21 11:21 PM, Damien Le Moal wrote:
> 
> On 2021/01/28 16:12, Chaitanya Kulkarni wrote:
> 
> 
> Introduce bio_new() helper and use it in blk-lib.c to allocate and
> initialize various non-optional or semi-optional members of the bio
> along with bio allocation done with bio_alloc(). Here we also calmp the
> max_bvecs for bio with BIO_MAX_PAGES before we pass to bio_alloc().
> 
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com><mailto:chaitanya.kulkarni@wdc.com>
> ---
>  block/blk-lib.c     |  6 +-----
>  include/linux/bio.h | 25 +++++++++++++++++++++++++
>  2 files changed, 26 insertions(+), 5 deletions(-)
> 
> diff --git a/block/blk-lib.c b/block/blk-lib.c
> index fb486a0bdb58..ec29415f00dd 100644
> --- a/block/blk-lib.c
> +++ b/block/blk-lib.c
> @@ -14,17 +14,13 @@ struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev,
>                         sector_t sect, unsigned op, unsigned opf,
>                         unsigned int nr_pages, gfp_t gfp)
>  {
> -       struct bio *new = bio_alloc(gfp, nr_pages);
> +       struct bio *new = bio_new(bdev, sect, op, opf, gfp, nr_pages);
> 
>         if (bio) {
>                 bio_chain(bio, new);
>                 submit_bio(bio);
>         }
> 
> -       new->bi_iter.bi_sector = sect;
> -       bio_set_dev(new, bdev);
> -       bio_set_op_attrs(new, op, opf);
> -
>         return new;
>  }
> 
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index c74857cf1252..2a09ba100546 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -826,5 +826,30 @@ static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
>         if (!is_sync_kiocb(kiocb))
>                 bio->bi_opf |= REQ_NOWAIT;
>  }
> +/**
> + * bio_new -   allcate and initialize new bio
> + * @bdev:      blockdev to issue discard for
> + * @sector:    start sector
> + * @op:                REQ_OP_XXX from enum req_opf
> + * @op_flags:  REQ_XXX from enum req_flag_bits
> + * @max_bvecs: maximum bvec to be allocated for this bio
> + * @gfp_mask:  memory allocation flags (for bio_alloc)
> + *
> + * Description:
> + *    Allocates, initializes common members, and returns a new bio.
> + */
> +static inline struct bio *bio_new(struct block_device *bdev, sector_t sector,
> +                                 unsigned int op, unsigned int op_flags,
> +                                 unsigned int max_bvecs, gfp_t gfp_mask)
> +{
> +       unsigned nr_bvec = clamp_t(unsigned int, max_bvecs, 0, BIO_MAX_PAGES);
> +       struct bio *bio = bio_alloc(gfp_mask, nr_bvec);
> 
> 
> I think that depending on the gfp_mask passed, bio can be NULL. So this should
> be checked.
> 
> 
> true, I'll add that check.
> 
> 
> 
> 
> +
> +       bio_set_dev(bio, bdev);
> +       bio->bi_iter.bi_sector = sector;
> +       bio_set_op_attrs(bio, op, op_flags);
> 
> 
> This function is obsolete. Open code this.
> 
> 
> true, will do.
> 
> 
> 
> 
> +
> +       return bio;
> +}
> 
>  #endif /* __LINUX_BIO_H */
> 
> 
> 
> Thanks for the comments Damien.

> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel@oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/ocfs2-devel