From: Omar Sandoval <osandov@xxxxxx> Hello, This series adds an API for reading compressed data on a filesystem without decompressing it as well as support for writing compressed data directly to the filesystem. As with the previous submissions, I've included a man page patch describing the API, and test cases and example programs are available [1]. This version reworks the VFS interface to be backward and forward compatible and support for writing inline and bookend extents to the Btrfs implementation. Patches 1-3 add the VFS support. Patches 4-7 are Btrfs cleanups necessary for the encoded I/O support that can go in independently of this series. Patches 8-10 are Btrfs prep patches. Patch 11 adds Btrfs encoded read support and patch 12 adds Btrfs encoded write support. A few TODOs remain: - Once we've settled on the interface, I'll add RWF_ENCODED support to fsstress and friends and send up the xfstests patches in [1]. - btrfs_encoded_read() still doesn't implement repair. Changes from v2 [2]: - Rebase on v5.4-rc8 - Add patch 1 introducing copy_struct_from_iter() as suggested by Aleksa - Rename O_ENCODED to O_ALLOW_ENCODED as suggested by Amir - Add arch-specific definitions of O_ALLOW_ENCODED for alpha, parisc, and sparc - Rework the VFS interface to be backward and forward compatible - Document the VFS interface as requested by Dave - Use __aligned_u64 for struct encoded_iov as noted by Aleksa - Fix len/unencoded_len mixup in mm/filemap.c as noted by Nikolay - Add support for writing inline and bookend extents to Btrfs - Use ENOBUFS for "buffers not big enough for encoded extent" case and E2BIG for "encoded_iov has unsupported fields" case Please share any comments on the API or implementation. Thanks! 1: https://github.com/osandov/xfstests/tree/rwf-encoded 2: https://lore.kernel.org/linux-btrfs/cover.1571164762.git.osandov@xxxxxx/ Omar Sandoval (12): iov_iter: add copy_struct_from_iter() fs: add O_ALLOW_ENCODED open flag fs: add RWF_ENCODED for reading/writing compressed data btrfs: get rid of trivial __btrfs_lookup_bio_sums() wrappers btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio() btrfs: remove dead snapshot-aware defrag code btrfs: make btrfs_ordered_extent naming consistent with btrfs_file_extent_item btrfs: add ram_bytes and offset to btrfs_ordered_extent btrfs: support different disk extent size for delalloc btrfs: optionally extend i_size in cow_file_range_inline() btrfs: implement RWF_ENCODED reads btrfs: implement RWF_ENCODED writes Documentation/filesystems/encoded_io.rst | 79 + Documentation/filesystems/index.rst | 1 + arch/alpha/include/uapi/asm/fcntl.h | 1 + arch/parisc/include/uapi/asm/fcntl.h | 1 + arch/sparc/include/uapi/asm/fcntl.h | 1 + fs/btrfs/compression.c | 15 +- fs/btrfs/compression.h | 5 +- fs/btrfs/ctree.h | 13 +- fs/btrfs/delalloc-space.c | 38 +- fs/btrfs/delalloc-space.h | 4 +- fs/btrfs/file-item.c | 54 +- fs/btrfs/file.c | 61 +- fs/btrfs/inode.c | 2463 +++++++++++----------- fs/btrfs/ordered-data.c | 106 +- fs/btrfs/ordered-data.h | 28 +- fs/btrfs/relocation.c | 9 +- fs/fcntl.c | 10 +- fs/namei.c | 4 + include/linux/fcntl.h | 2 +- include/linux/fs.h | 16 + include/linux/uio.h | 2 + include/trace/events/btrfs.h | 6 +- include/uapi/asm-generic/fcntl.h | 4 + include/uapi/linux/fs.h | 33 +- lib/iov_iter.c | 82 + mm/filemap.c | 165 +- 26 files changed, 1807 insertions(+), 1396 deletions(-) create mode 100644 Documentation/filesystems/encoded_io.rst -- 2.24.0
