| Message ID | 20220722071228.146690-1-ebiggers@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | make statx() return DIO alignment information | expand |
On Fri, 2022-07-22 at 00:12 -0700, Eric Biggers wrote: > 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'm sending separately. > > Note, f2fs has one corner case where DIO reads are allowed but not DIO > writes. The proposed statx fields can't represent this. My proposal > (patch 6) is to just eliminate this case, as it seems much too weird. > But I'd appreciate any feedback on that part. > > This patchset applies to v5.19-rc7. > > Changed v3 => 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 v2 => 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 v1 => v2: > - No changes. > > Eric Biggers (9): > 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: don't allow DIO reads but not DIO writes > f2fs: simplify f2fs_force_buffered_io() > f2fs: support STATX_DIOALIGN > xfs: support STATX_DIOALIGN > > block/bdev.c | 25 ++++++++++++++++++++ > fs/crypto/inline_crypt.c | 49 +++++++++++++++++++-------------------- > fs/ext4/ext4.h | 1 + > fs/ext4/file.c | 37 ++++++++++++++++++++--------- > fs/ext4/inode.c | 36 ++++++++++++++++++++++++++++ > fs/f2fs/f2fs.h | 45 ----------------------------------- > fs/f2fs/file.c | 45 ++++++++++++++++++++++++++++++++++- > fs/stat.c | 14 +++++++++++ > fs/xfs/xfs_iops.c | 9 +++++++ > include/linux/blkdev.h | 4 ++++ > include/linux/fscrypt.h | 7 ++---- > include/linux/stat.h | 2 ++ > include/uapi/linux/stat.h | 4 +++- > 13 files changed, 190 insertions(+), 88 deletions(-) > > base-commit: ff6992735ade75aae3e35d16b17da1008d753d28 Hi Eric, Can I ask what your plans are with this set? I didn't see it in linux-next yet, so I wasn't sure when you were looking to get it merged. I'm working on patches to add a new statx field for the i_version counter as well and I want to make sure that our work doesn't collide. Thanks,
On Fri, Aug 26, 2022 at 01:19:37PM -0400, Jeff Layton wrote: > On Fri, 2022-07-22 at 00:12 -0700, Eric Biggers wrote: > > 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'm sending separately. > > > > Note, f2fs has one corner case where DIO reads are allowed but not DIO > > writes. The proposed statx fields can't represent this. My proposal > > (patch 6) is to just eliminate this case, as it seems much too weird. > > But I'd appreciate any feedback on that part. > > > > This patchset applies to v5.19-rc7. > > > > Changed v3 => 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 v2 => 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 v1 => v2: > > - No changes. > > > > Eric Biggers (9): > > 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: don't allow DIO reads but not DIO writes > > f2fs: simplify f2fs_force_buffered_io() > > f2fs: support STATX_DIOALIGN > > xfs: support STATX_DIOALIGN > > > > block/bdev.c | 25 ++++++++++++++++++++ > > fs/crypto/inline_crypt.c | 49 +++++++++++++++++++-------------------- > > fs/ext4/ext4.h | 1 + > > fs/ext4/file.c | 37 ++++++++++++++++++++--------- > > fs/ext4/inode.c | 36 ++++++++++++++++++++++++++++ > > fs/f2fs/f2fs.h | 45 ----------------------------------- > > fs/f2fs/file.c | 45 ++++++++++++++++++++++++++++++++++- > > fs/stat.c | 14 +++++++++++ > > fs/xfs/xfs_iops.c | 9 +++++++ > > include/linux/blkdev.h | 4 ++++ > > include/linux/fscrypt.h | 7 ++---- > > include/linux/stat.h | 2 ++ > > include/uapi/linux/stat.h | 4 +++- > > 13 files changed, 190 insertions(+), 88 deletions(-) > > > > base-commit: ff6992735ade75aae3e35d16b17da1008d753d28 > > Hi Eric, > > Can I ask what your plans are with this set? I didn't see it in > linux-next yet, so I wasn't sure when you were looking to get it merged. > I'm working on patches to add a new statx field for the i_version > counter as well and I want to make sure that our work doesn't collide. > I've just sent v5. I guess I'll try to get it merged for 6.1. We were a bit stuck on the read-only DIO issue. All things considered though, including that Christoph thinks it's possible for f2fs to support DIO writes on zoned block devices, I'm willing to bet that read-only DIO doesn't really matter enough for it to be worth it to add a direction field to STATX_DIOALIGN (which would make it harder to use STATX_DIOALIGN, as the field would always have to be checked). - Eric
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'm sending separately. Note, f2fs has one corner case where DIO reads are allowed but not DIO writes. The proposed statx fields can't represent this. My proposal (patch 6) is to just eliminate this case, as it seems much too weird. But I'd appreciate any feedback on that part. This patchset applies to v5.19-rc7. Changed v3 => 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 v2 => 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 v1 => v2: - No changes. Eric Biggers (9): 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: don't allow DIO reads but not DIO writes f2fs: simplify f2fs_force_buffered_io() f2fs: support STATX_DIOALIGN xfs: support STATX_DIOALIGN block/bdev.c | 25 ++++++++++++++++++++ fs/crypto/inline_crypt.c | 49 +++++++++++++++++++-------------------- fs/ext4/ext4.h | 1 + fs/ext4/file.c | 37 ++++++++++++++++++++--------- fs/ext4/inode.c | 36 ++++++++++++++++++++++++++++ fs/f2fs/f2fs.h | 45 ----------------------------------- fs/f2fs/file.c | 45 ++++++++++++++++++++++++++++++++++- fs/stat.c | 14 +++++++++++ fs/xfs/xfs_iops.c | 9 +++++++ include/linux/blkdev.h | 4 ++++ include/linux/fscrypt.h | 7 ++---- include/linux/stat.h | 2 ++ include/uapi/linux/stat.h | 4 +++- 13 files changed, 190 insertions(+), 88 deletions(-) base-commit: ff6992735ade75aae3e35d16b17da1008d753d28