From f85781fb505ec02891734e77f7c69a9c85c99ec3 Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Mon, 17 Aug 2020 11:18:21 -0500 Subject: btrfs: switch to iomap for direct IO We're using direct io implementation based on buffer heads. This patch switches to the new iomap infrastructure. Switch from __blockdev_direct_IO() to iomap_dio_rw(). Rename btrfs_get_blocks_direct() to btrfs_dio_iomap_begin() and use it as iomap_begin() for iomap direct I/O functions. This function allocates and locks all the blocks required for the I/O. btrfs_submit_direct() is used as the submit_io() hook for direct I/O ops. Since we need direct I/O reads to go through iomap_dio_rw(), we change file_operations.read_iter() to a btrfs_file_read_iter() which calls btrfs_direct_IO() for direct reads and falls back to generic_file_buffered_read() for incomplete reads and buffered reads. We don't need address_space.direct_IO() anymore: set it to noop. Similarly, we don't need flags used in __blockdev_direct_IO(). iomap is capable of direct I/O reads from a hole, so we don't need to return -ENOENT. Btrfs direct I/O is now done under i_rwsem, shared in case of reads and exclusive in case of writes. This guards against simultaneous truncates. Use iomap->iomap_end() to check for failed or incomplete direct I/O: - for writes, call __endio_write_update_ordered() - for reads, unlock extents btrfs_dio_data is now hooked in iomap->private and not current->journal_info. It carries the reservation variable and the amount of data submitted, so we can calculate the amount of data to call __endio_write_update_ordered in case of an error. This patch removes last use of struct buffer_head from btrfs. Reviewed-by: Josef Bacik Signed-off-by: Goldwyn Rodrigues Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/btrfs/Kconfig') diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig index 575636f6491e..68b95ad82126 100644 --- a/fs/btrfs/Kconfig +++ b/fs/btrfs/Kconfig @@ -14,6 +14,7 @@ config BTRFS_FS select LZO_DECOMPRESS select ZSTD_COMPRESS select ZSTD_DECOMPRESS + select FS_IOMAP select RAID6_PQ select XOR_BLOCKS select SRCU -- cgit v1.2.3