8481dd80ab
Currently we use fixed size u16 bitmap for subpage bitmap. This is fine for 4K sectorsize with 64K page size. But for 4K sectorsize and larger page size, the bitmap is too small, while for smaller page size like 16K, u16 bitmaps waste too much space. Here we introduce a new helper structure, btrfs_subpage_bitmap_info, to record the proper bitmap size, and where each bitmap should start at. By this, we can later compact all subpage bitmaps into one u32 bitmap. This patch is the first step. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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.