On 13.12.19 г. 21:57 ч., Goldwyn Rodrigues wrote: > 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 and tested on v5.5-rc1. I have tested it against > xfstests/btrfs. > > The tree is available at > https://github.com/goldwynr/linux/tree/btrfs-iomap-dio > > 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. > > Changes since v3 > - Fixed freeze on generic/095. Use iomap_end() to account for > failed/incomplete dio instead of btrfs_dio_data > > Changes since v4 > - moved lockdep_assert_held() to functions calling iomap_dio_rw() > This may be called immidiately after calling inode lock and > may feel not required, but it seems important. > - Removed comments which are no longer required > - Changed commit comments to make them more appropriate > > Changes since v5 > - restore inode_dio_wait() in truncate I'm confused about this - you no longer call inode_dio_begin after patch 4/8 so inode_dio_wait which is left intact in truncate can never trigger a wait really. Exclusion is provided by the fact that btrfs_direct_IO is called with rwsem held shared and truncate holds it exclusive? So what necessitated restoring inode_dio_wait? Another point, I don't see whether you have explicitly addressed concerns raised in: https://lore.kernel.org/linux-btrfs/20191212003043.31093-1-rgoldwyn@xxxxxxx/T/#me7f96506e5a1d921d05b76d01ecf6ea1ebcea594 > - Removed lockdep_assert_held() near callers > > -- > Goldwyn > >
