Hey Christoph, Hey Jan, Hey Jens, This opens block devices as files. Instead of introducing a separate indirection into bdev_open_by_*() vis struct bdev_handle we can just make bdev_file_open_by_*() return a struct file. Opening and closing a block device from setup_bdev_super() and in all other places just becomes equivalent to opening and closing a file. This has held up in xfstests and in blktests so far and it seems stable and clean. The equivalence of opening and closing block devices to regular files is a win in and of itself imho. Added to that is the ability to do away with struct bdev_handle completely and make various low-level helpers private to the block layer. All places were we currently stash a struct bdev_handle we just stash a file and use an accessor such as file_bdev() akin to I_BDEV() to get to the block device. It's now also possible to use file->f_mapping as a replacement for bdev->bd_inode->i_mapping and file->f_inode or file->f_mapping->host as an alternative to bdev->bd_inode allowing us to significantly reduce or even fully remove bdev->bd_inode in follow-up patches. In addition, we could get rid of sb->s_bdev and various other places that stash the block device directly and instead stash the block device file. Again, this is follow-up work. Thanks! Christian Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> --- Changes in v2: - This is not an RFC anymore. - The patches to convert all of fs/buffer.c and associated helpers to struct file have been split out of the core infrastructure. - Various renaming of helpers in response to v1. - Link to v1: https://lore.kernel.org/r/20240103-vfs-bdev-file-v1-0-6c8ee55fb6ef@xxxxxxxxxx --- Christian Brauner (34): bdev: open block device as files block/ioctl: port blkdev_bszset() to file block/genhd: port disk_scan_partitions() to file md: port block device access to file swap: port block device usage to file power: port block device access to file xfs: port block device access to files drbd: port block device access to file pktcdvd: port block device access to file rnbd: port block device access to file xen: port block device access to file zram: port block device access to file bcache: port block device access to files block2mtd: port device access to files nvme: port block device access to file s390: port block device access to file target: port block device access to file bcachefs: port block device access to file btrfs: port device access to file erofs: port device access to file ext4: port block device access to file f2fs: port block device access to files jfs: port block device access to file nfs: port block device access to files ocfs2: port block device access to file reiserfs: port block device access to file bdev: remove bdev_open_by_path() bdev: make bdev_release() private to block layer bdev: make struct bdev_handle private to the block layer bdev: remove bdev pointer from struct bdev_handle block: use file->f_op to indicate restricted writes block: remove bdev_handle completely block: expose bdev_file_inode() ext4: rely on sb->f_bdev only block/bdev.c | 249 ++++++++++++++++++++++-------------- block/blk.h | 6 + block/fops.c | 48 ++++--- block/genhd.c | 12 +- block/ioctl.c | 9 +- drivers/block/drbd/drbd_int.h | 4 +- drivers/block/drbd/drbd_nl.c | 58 ++++----- drivers/block/pktcdvd.c | 68 +++++----- drivers/block/rnbd/rnbd-srv.c | 28 ++-- drivers/block/rnbd/rnbd-srv.h | 2 +- drivers/block/xen-blkback/blkback.c | 4 +- drivers/block/xen-blkback/common.h | 4 +- drivers/block/xen-blkback/xenbus.c | 37 +++--- drivers/block/zram/zram_drv.c | 26 ++-- drivers/block/zram/zram_drv.h | 2 +- drivers/md/bcache/bcache.h | 4 +- drivers/md/bcache/super.c | 74 +++++------ drivers/md/dm.c | 23 ++-- drivers/md/md.c | 12 +- drivers/md/md.h | 2 +- drivers/mtd/devices/block2mtd.c | 46 +++---- drivers/nvme/target/io-cmd-bdev.c | 16 +-- drivers/nvme/target/nvmet.h | 2 +- drivers/s390/block/dasd.c | 10 +- drivers/s390/block/dasd_genhd.c | 36 +++--- drivers/s390/block/dasd_int.h | 2 +- drivers/s390/block/dasd_ioctl.c | 2 +- drivers/target/target_core_iblock.c | 18 +-- drivers/target/target_core_iblock.h | 2 +- drivers/target/target_core_pscsi.c | 22 ++-- drivers/target/target_core_pscsi.h | 2 +- fs/bcachefs/super-io.c | 20 +-- fs/bcachefs/super_types.h | 2 +- fs/btrfs/dev-replace.c | 14 +- fs/btrfs/ioctl.c | 16 +-- fs/btrfs/volumes.c | 92 ++++++------- fs/btrfs/volumes.h | 4 +- fs/cramfs/inode.c | 2 +- fs/erofs/data.c | 6 +- fs/erofs/internal.h | 2 +- fs/erofs/super.c | 16 +-- fs/ext4/dir.c | 2 +- fs/ext4/ext4.h | 2 +- fs/ext4/ext4_jbd2.c | 2 +- fs/ext4/fast_commit.c | 2 +- fs/ext4/fsmap.c | 8 +- fs/ext4/super.c | 87 ++++++------- fs/f2fs/f2fs.h | 2 +- fs/f2fs/super.c | 12 +- fs/file_table.c | 36 +++++- fs/jfs/jfs_logmgr.c | 26 ++-- fs/jfs/jfs_logmgr.h | 2 +- fs/jfs/jfs_mount.c | 2 +- fs/nfs/blocklayout/blocklayout.h | 2 +- fs/nfs/blocklayout/dev.c | 68 +++++----- fs/ocfs2/cluster/heartbeat.c | 32 ++--- fs/reiserfs/journal.c | 38 +++--- fs/reiserfs/procfs.c | 2 +- fs/reiserfs/reiserfs.h | 8 +- fs/romfs/super.c | 2 +- fs/super.c | 18 +-- fs/xfs/xfs_buf.c | 10 +- fs/xfs/xfs_buf.h | 4 +- fs/xfs/xfs_super.c | 43 +++---- include/linux/blkdev.h | 18 +-- include/linux/device-mapper.h | 2 +- include/linux/file.h | 2 + include/linux/fs.h | 4 +- include/linux/pktcdvd.h | 4 +- include/linux/swap.h | 2 +- kernel/power/swap.c | 28 ++-- mm/swapfile.c | 22 ++-- 72 files changed, 791 insertions(+), 705 deletions(-) --- base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d change-id: 20240103-vfs-bdev-file-1208da73d7ea
