[v6,0/3] per-io hints and FDP

Message

Kanchan Joshi Sept. 24, 2024, 9:24 a.m. UTC

Another spin to incorporate the feedback from LPC and previous
iteration. The series adds two capabilities:
- FDP support at NVMe level (patch #1)
- Per-io hinting via io_uring (patch #3)
Patch #2 is needed to do per-io hints.

The motivation and interface details are present in the commit
descriptions.

Testing:
Done with fcntl and liburing based custom applications.
On raw block device, ext4, xfs, btrfs and F2FS.
Checked that no regression occurs for application that use per-inode
hints.
Checked that per-io hints, when passed, take the precedence over per-inode
hints.

Changes since v5:
- Drop placement hints
- Add per-io hint interface

Changes since v4:
- Retain the size/type checking on the enum (Bart)
- Use the name "*_lifetime_hint" rather than "*_life_hint" (Bart)

Changes since v3:
- 4 new patches to introduce placement hints
- Make nvme patch use the placement hints rather than lifetime hints

Changes since v2:
- Base it on nvme-6.11 and resolve a merge conflict

Changes since v1:
- Reduce the fetched plids from 128 to 6 (Keith)
- Use struct_size for a calculation (Keith)
- Handle robot/sparse warning

Kanchan Joshi (3):
  nvme: enable FDP support
  block, fs: restore kiocb based write hint processing
  io_uring: enable per-io hinting capability

 block/fops.c                  |  6 +--
 drivers/nvme/host/core.c      | 70 +++++++++++++++++++++++++++++++++++
 drivers/nvme/host/nvme.h      |  4 ++
 fs/aio.c                      |  1 +
 fs/cachefiles/io.c            |  1 +
 fs/direct-io.c                |  2 +-
 fs/fcntl.c                    | 22 -----------
 fs/iomap/direct-io.c          |  2 +-
 include/linux/fs.h            |  8 ++++
 include/linux/nvme.h          | 19 ++++++++++
 include/linux/rw_hint.h       | 24 ++++++++++++
 include/uapi/linux/io_uring.h | 10 +++++
 io_uring/rw.c                 | 20 ++++++++++
 13 files changed, 162 insertions(+), 27 deletions(-)