A reminder to please review this version.
v3:
- batch file->rsrc renames into a signle patch when possible
- fix other review changes from v2
- fix checkpatch warnings
v2:
- drop readv/writev with fixed buffers patch
- handle ref_nodes both both files/buffers with a single ref_list
- make file/buffer handling more unified
This patchset implements a set of enhancements to buffer registration
consistent with existing file registration functionality:
- buffer registration updates IORING_REGISTER_BUFFERS_UPDATE
IORING_OP_BUFFERS_UPDATE
- buffer registration sharing IORING_SETUP_SHARE_BUF
IORING_SETUP_ATTACH_BUF
I have kept the original patchset unchanged for the most part to
facilitate reviewing and so this set adds a number of additional patches
mostly making file/buffer handling more unified.
Patch 1-2 modularize existing buffer registration code.
Patch 3-7 generalize fixed_file functionality to fixed_rsrc.
Patch 8 applies fixed_rsrc functionality for fixed buffers support.
Patch 9-10 generalize files_update functionality to rsrc_update.
Patch 11 implements buffer registration update, and introduces
IORING_REGISTER_BUFFERS_UPDATE and IORING_OP_BUFFERS_UPDATE, consistent
with file registration update.
Patch 12 generalizes fixed resource allocation
Patch 13 implements buffer sharing among multiple rings; it works as follows:
- A new ring, A, is setup. Since no buffers have been registered, the
registered buffer state is an empty set, Z. That's different from the
NULL state in current implementation.
- Ring B is setup, attaching to Ring A. It's also attaching to it's
buffer registrations, now we have two references to the same empty
set, Z.
- Ring A registers buffers into set Z, which is no longer empty.
- Ring B sees this immediately, since it's already sharing that set.
Testing
I have used liburing file-{register,update} tests as models for
buffer-{register,update,share}, tests and they run ok.
TBD
- I tried to use a single opcode for files/buffers but ran into an
issue since work_flags is different for files/buffers. This should
be ok for the most part since req->work.flags is ultimately examined;
however, there are place where io_op_defs[opcode].work_flags is examined
directly, and I wasn't sure what would the best way to handle that.
- Need to still address Pavel's comments about deadlocks. I figure
to send out the set anyway since this is a last patch and may even be
handled separately.
Bijan Mottahedeh (13):
io_uring: modularize io_sqe_buffer_register
io_uring: modularize io_sqe_buffers_register
io_uring: rename file related variables to rsrc
io_uring: generalize io_queue_rsrc_removal
io_uring: separate ref_list from fixed_rsrc_data
io_uring: generalize fixed_file_ref_node functionality
io_uring: add rsrc_ref locking routines
io_uring: implement fixed buffers registration similar to fixed files
io_uring: create common fixed_rsrc_ref_node handling routines
io_uring: generalize files_update functionlity to rsrc_update
io_uring: support buffer registration updates
io_uring: create common fixed_rsrc_data allocation routines.
io_uring: support buffer registration sharing
fs/io_uring.c | 1004 +++++++++++++++++++++++++++++------------
include/uapi/linux/io_uring.h | 12 +-
2 files changed, 735 insertions(+), 281 deletions(-)
