This is an effort to use iomap for direct I/O in btrfs. This would change the call from __blockdev_direct_io() to iomap_dio_rw(). The main objective is to lose the buffer head and use bio defined by iomap code, and hopefully to use more of generic-FS codebase. These patches are based on xfs/iomap-for-next, though I tested it against the patches on xfs/iomap-for-next on top of v5.4.1 (there are no changes to existing patches). The tree is available at https://github.com/goldwynr/linux/tree/btrfs-iomap-dio I have tested it against xfstests/btrfs. Changes since v1 - Incorporated back the efficiency change for inode locking - Review comments about coding style and git comments - Merge related patches into one - Direct read to go through btrfs_direct_IO() - Removal of no longer used function dio_end_io() Changes since v2 - aligning iomap offset/length to the position/length of I/O - Removed btrfs_dio_data - Removed BTRFS_INODE_READDIO_NEED_LOCK - Re-incorporating write efficiency changes caused lockdep_assert() in iomap to be triggered, remove that code. fs/btrfs/btrfs_inode.h | 18 --- fs/btrfs/ctree.h | 1 fs/btrfs/extent_io.c | 37 ++---- fs/btrfs/extent_io.h | 2 fs/btrfs/file.c | 21 +++ fs/btrfs/inode.c | 267 ++++++++++++++++--------------------------------- fs/direct-io.c | 19 --- fs/iomap/direct-io.c | 16 +- include/linux/fs.h | 3 include/linux/iomap.h | 2 mm/filemap.c | 13 +- 11 files changed, 149 insertions(+), 250 deletions(-) -- Goldwyn
