This patchset makes the statx() system call return direct I/O (DIO) alignment information. This allows userspace to easily determine whether a file supports DIO, and if so with what alignment restrictions. Patch 1 adds the basic VFS support for STATX_DIOALIGN. Patch 2 wires it up for all block device files. The remaining patches wire it up for regular files on ext4, f2fs, and xfs. Support for regular files on other filesystems can be added later. I've also written a man-pages patch, which I sent separately: https://lore.kernel.org/r/20220722074229.148925-1-ebiggers@xxxxxxxxxx Note, f2fs has a corner case where DIO reads are allowed but not DIO writes. The proposed statx fields can't represent this. The current proposal just reports that DIO is unsupported in this case. This patchset applies to v6.0-rc2. Changed in v5: - Accounted for the DIO changes in 6.0 by setting dio_mem_align to the DMA alignment instead of the logical block size where needed. - Dropped the patch "f2fs: don't allow DIO reads but not DIO writes". - Added some Reviewed-by and Acked-by tags. Changed in v4: - Added xfs support. - Moved the helper function for block devices into block/bdev.c. - Adjusted the ext4 patch to not introduce a bug where misaligned DIO starts being allowed on encrypted files when it gets combined with the patch "iomap: add support for dma aligned direct-io" that is queued in the block tree for 5.20. - Made a simplification in fscrypt_dio_supported(). Changed in v3: - Dropped the stx_offset_align_optimal field, since its purpose wasn't clearly distinguished from the existing stx_blksize. - Renamed STATX_IOALIGN to STATX_DIOALIGN, to reflect the new focus on DIO only. - Similarly, renamed stx_{mem,offset}_align_dio to stx_dio_{mem,offset}_align, to reflect the new focus on DIO only. - Wired up STATX_DIOALIGN on block device files. Changed in v2: - No changes. Eric Biggers (8): statx: add direct I/O alignment information vfs: support STATX_DIOALIGN on block devices fscrypt: change fscrypt_dio_supported() to prepare for STATX_DIOALIGN ext4: support STATX_DIOALIGN f2fs: move f2fs_force_buffered_io() into file.c f2fs: simplify f2fs_force_buffered_io() f2fs: support STATX_DIOALIGN xfs: support STATX_DIOALIGN block/bdev.c | 23 ++++++++++++++++++ fs/crypto/inline_crypt.c | 49 +++++++++++++++++++-------------------- fs/ext4/ext4.h | 1 + fs/ext4/file.c | 37 ++++++++++++++++++++--------- fs/ext4/inode.c | 37 +++++++++++++++++++++++++++++ fs/f2fs/f2fs.h | 40 -------------------------------- fs/f2fs/file.c | 43 +++++++++++++++++++++++++++++++++- fs/stat.c | 14 +++++++++++ fs/xfs/xfs_iops.c | 10 ++++++++ include/linux/blkdev.h | 4 ++++ include/linux/fscrypt.h | 7 ++---- include/linux/stat.h | 2 ++ include/uapi/linux/stat.h | 4 +++- 13 files changed, 188 insertions(+), 83 deletions(-) base-commit: 1c23f9e627a7b412978b4e852793c5e3c3efc555 -- 2.37.2
