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Qu Wenruo
3f255ece2f
Since extent_map structure has the all the needed members to represent a file extent directly, we can apply all the file extent sanity checks to an extent map. The new sanity checks will cross check both the old members (block_start/block_len/orig_start) and the new members (disk_bytenr/disk_num_bytes/offset). There is a special case for offset/orig_start/start cross check, we only do such sanity check for compressed extent, as only compressed read/encoded write really utilize orig_start. This can be proved by the cleanup patch of orig_start. The checks happens at the following times: - add_extent_mapping() This is for newly added extent map - replace_extent_mapping() This is for btrfs_drop_extent_map_range() and split_extent_map() - try_merge_map() For a lot of call sites we have to properly populate all the members to pass the sanity check, meanwhile the following code needs extra modification: - setup_file_extents() from inode-tests The file extents layout of setup_file_extents() is already too invalid that tree-checker would reject most of them in real world. However there is just a special unaligned regular extent which has mismatched disk_num_bytes (4096) and ram_bytes (4096 - 1). So instead of dropping the whole test case, here we just unify disk_num_bytes and ram_bytes to 4096 - 1. - test_case_7() from extent-map-tests An extent is inserted with 16K length, but on-disk extent size is only 4K. This means it must be a compressed extent, so set the compressed flag for it. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Filipe Manana <fdmanana@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 reStructuredText 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.