[RFC,v2,for-6.8/block,00/18] block: don't access bd_inode directly from other modules

Message

Yu Kuai Dec. 11, 2023, 2:05 p.m. UTC

From: Yu Kuai <[e-mail]>

Changes in v2:
 - remove some bdev apis that is not necessary;
 - pass in offset for bdev_read_folio() and __bdev_get_folio();
 - remove bdev_gfp_constraint() and add a new helper in fs/buffer.c to
 prevent access bd_indoe() directly from mapping_gfp_constraint() in
 ext4.(patch 15, 16);
 - remove block_device_ejected() from ext4.

Noted that following is not changed yet since v1:
- Chirstoph suggested to remove invalidate_inode_pages2() from
xen_update_blkif_status(), however, this sync_bdev() + invalidate_bdev()
is used from many modules, and I'll leave this for later if we want to
kill all of them.
- Matthew suggested that pass in valid file_ra_state for cramfs,
however, I don't see an easy way to do this for cramfs_lookup() and
cramfs_read_super().

Patch 1 add some bdev apis, then follow up patches will use these apis
to avoid access bd_inode directly, and hopefully the field bd_inode can
be removed eventually(after figure out a way for fs/buffer.c).

Yu Kuai (18):
  block: add some bdev apis
  xen/blkback: use bdev api in xen_update_blkif_status()
  bcache: use bdev api in read_super()
  mtd: block2mtd: use bdev apis
  s390/dasd: use bdev api in dasd_format()
  scsicam: use bdev api in scsi_bios_ptable()
  bcachefs: remove dead function bdev_sectors()
  bio: export bio_add_folio_nofail()
  btrfs: use bdev apis
  cramfs: use bdev apis in cramfs_blkdev_read()
  erofs: use bdev api
  gfs2: use bdev api
  nilfs2: use bdev api in nilfs_attach_log_writer()
  jbd2: use bdev apis
  buffer: add a new helper to read sb block
  ext4: use new helper to read sb block
  ext4: remove block_device_ejected()
  ext4: use bdev apis

 block/bdev.c                       | 70 ++++++++++++++++++++++++++
 block/bio.c                        |  1 +
 block/blk.h                        |  2 -
 drivers/block/xen-blkback/xenbus.c |  3 +-
 drivers/md/bcache/super.c          | 11 ++--
 drivers/mtd/devices/block2mtd.c    | 81 +++++++++++++-----------------
 drivers/s390/block/dasd_ioctl.c    |  5 +-
 drivers/scsi/scsicam.c             |  4 +-
 fs/bcachefs/util.h                 |  5 --
 fs/btrfs/disk-io.c                 | 71 ++++++++++++--------------
 fs/btrfs/volumes.c                 | 17 +++----
 fs/btrfs/zoned.c                   | 15 +++---
 fs/buffer.c                        | 68 +++++++++++++++++--------
 fs/cramfs/inode.c                  | 36 +++++--------
 fs/erofs/data.c                    | 18 ++++---
 fs/erofs/internal.h                |  2 +
 fs/ext4/dir.c                      |  6 +--
 fs/ext4/ext4.h                     | 13 -----
 fs/ext4/ext4_jbd2.c                |  6 +--
 fs/ext4/inode.c                    |  8 +--
 fs/ext4/super.c                    | 66 ++++--------------------
 fs/ext4/symlink.c                  |  2 +-
 fs/gfs2/glock.c                    |  2 +-
 fs/gfs2/ops_fstype.c               |  2 +-
 fs/jbd2/journal.c                  |  3 +-
 fs/jbd2/recovery.c                 |  6 +--
 fs/nilfs2/segment.c                |  2 +-
 include/linux/blkdev.h             | 17 +++++++
 include/linux/buffer_head.h        | 18 ++++++-
 29 files changed, 301 insertions(+), 259 deletions(-)