40ebc18b99
Pull block devices as files from Christian Brauner: 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 if we want this. * series 'Open block devices as files' of https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-0-adbd023e19cc@kernel.org: (35 commits) file: add alloc_file_pseudo_noaccount() file: prepare for new helper init: flush async file closing block: remove bdev_handle completely block: don't rely on BLK_OPEN_RESTRICT_WRITES when yielding write access bdev: remove bdev pointer from struct bdev_handle bdev: make struct bdev_handle private to the block layer bdev: make bdev_{release, open_by_dev}() private to block layer bdev: remove bdev_open_by_path() reiserfs: port block device access to file ocfs2: port block device access to file nfs: port block device access to files jfs: port block device access to file f2fs: port block device access to files ext4: port block device access to file erofs: port device access to file btrfs: port device access to file bcachefs: port block device access to file target: port block device access to file s390: port block device access to file nvme: port block device access to file block2mtd: port device access to files bcache: port block device access to files ... Signed-off-by: Christian Brauner <brauner@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.