Hi Christian, UFS devices are widely used in mobile applications, e.g. in smartphones. UFS vendors need data lifetime information to achieve good performance. Providing data lifetime information to UFS devices can result in up to 40% lower write amplification. Hence this patch series that restores the bi_write_hint member in struct bio. After this patch series has been merged, patches that implement data lifetime support in the SCSI disk (sd) driver will be sent to the Linux kernel SCSI maintainer. The following changes are included in this patch series: - Improvements for the F_GET_RW_HINT and F_SET_RW_HINT fcntls. - Move enum rw_hint into a new header file. - Support F_SET_RW_HINT for block devices to make it easy to test data lifetime support. - Restore the bio.bi_write_hint member and restore support in the VFS layer and also in the block layer for data lifetime information. The shell script that has been used to test the patch series combined with the SCSI patches is available at the end of this cover letter. Please consider this patch series for the next merge window. Thanks, Bart. Changes compared to v1: - Rebased this patch series on top of the vfs.all branch. - Use READ_ONCE() / WRITE_ONCE() to access i_write_hint in the fcntl implementation. Bart Van Assche (6): fs: Fix rw_hint validation fs: Verify write lifetime constants at compile time fs: Split fcntl_rw_hint() fs: Move enum rw_hint into a new header file fs: Propagate write hints to the struct block_device inode block, fs: Restore the per-bio/request data lifetime fields block/bio.c | 2 ++ block/blk-crypto-fallback.c | 1 + block/blk-merge.c | 8 +++++ block/blk-mq.c | 2 ++ block/bounce.c | 1 + block/fops.c | 3 ++ fs/buffer.c | 12 ++++--- fs/direct-io.c | 2 ++ fs/f2fs/f2fs.h | 1 + fs/fcntl.c | 64 +++++++++++++++++++++++-------------- fs/inode.c | 1 + fs/iomap/buffered-io.c | 1 + fs/iomap/direct-io.c | 1 + fs/mpage.c | 1 + include/linux/blk-mq.h | 2 ++ include/linux/blk_types.h | 2 ++ include/linux/fs.h | 16 ++-------- include/linux/rw_hint.h | 24 ++++++++++++++ 18 files changed, 102 insertions(+), 42 deletions(-) create mode 100644 include/linux/rw_hint.h
