Messages in this thread | | | From | Ammar Faizi <> | Subject | [RFC PATCH v4 0/3] Add sendto(2) and recvfrom(2) support for io_uring | Date | Fri, 7 Jan 2022 07:00:02 +0700 |
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Hello,
This RFC patchset adds sendto(2) and recvfrom(2) support for io_uring. It also addresses an issue in the liburing GitHub repository [1].
## Motivations 1) By using `sendto()` and `recvfrom()` we can make the submission simpler compared to always using `sendmsg()` and `recvmsg()` from the userspace.
2) There is a historical patch that tried to add the same functionality, but did not end up being applied. [2]
On Tue, 7 Jul 2020 12:29:18 -0600, Jens Axboe <axboe@kernel.dk> wrote: > In a private conversation with the author, a good point was brought > up that the sendto/recvfrom do not require an allocation of an async > context, if we need to defer or go async with the request. I think > that's a major win, to be honest. There are other benefits as well > (like shorter path), but to me, the async less part is nice and will > reduce overhead
## Changes summary There are 3 patches in this series.
PATCH 1/3 renames io_recv to io_recvfrom and io_send to io_sendto. Note that:
send(sockfd, buf, len, flags);
is equivalent to
sendto(sockfd, buf, len, flags, NULL, 0);
and
recv(sockfd, buf, len, flags);
is equivalent to
recvfrom(sockfd, buf, len, flags, NULL, NULL);
So it is saner to have `send` and `recv` directed to `sendto` and `recvfrom` instead of the opposite with respect to the name.
PATCH 2/3 makes `move_addr_to_user()` be a non static function. This function lives in net/socket.c, we need to call this from io_uring to add `recvfrom()` support for io_uring. Added net files maintainers to the CC list.
PATCH 3/3 adds `sendto(2)` and `recvfrom(2)` support for io_uring. Added two new opcodes: IORING_OP_SENDTO and IORING_OP_RECVFROM.
## How to test This patchset is based on "for-next" branch in Jens' tree commit:
c1537fd063e2f1dbd96d8f68b405a66297ee306f ("Merge branch 'for-5.17/drivers' into for-next")
It is also available in the Git repository at:
https://github.com/ammarfaizi2/linux-block.git ammarfaizi2/linux-block/io_uring-recvfrom-sendto.v4
Test with liburing (added the liburing support, docs, and test program), the liburing support is based on liburing "master" branch commit:
918d8061ffdfdf253806a1e8e141c71644e678bd ("Remove getdents support")
It is available in the Git repository at:
https://github.com/ammarfaizi2/liburing.git sendto-recvfrom.v2
Please review and comment.
---
RFC v4 (this patchset): - Rebase the work (sync with "for-next" branch in Jens' tree).
- Remove Tested-by tag from Nugra as we have changes.
- (Address Praveen's comment) Zero `sendto_addr_len` and `recvfrom_addr_len` on prep when the `req->opcode` is not `IORING_OP_{SENDTO,RECVFROM}`.
RFC v3: - Fix build error when CONFIG_NET is undefined for PATCH 1/3. I tried to fix it in PATCH 3/3, but it should be fixed in PATCH 1/3, otherwise it breaks the build in PATCH 1/3.
- Added `io_uring_prep_{sendto,recvfrom}` docs to the liburing.
RFC v2: - Rebase the work, now this patchset is based on commit bb3294e22482db4b7ec ("Merge branch 'for-5.17/drivers' into for-next").
- In `io_recvfrom()`, mark the error check of `move_addr_to_user()` call as unlikely.
- Fix build error when CONFIG_NET is undefined.
- Update liburing test (the branch is still the same, just force pushed).
- Added Nugra to CC list (tester).
--- RFC v3: https://lore.kernel.org/io-uring/20211230013154.102910-1-ammar.faizi@intel.com/ RFC v2: https://lore.kernel.org/io-uring/20211230114846.137954-1-ammar.faizi@intel.com/ RFC v1: https://lore.kernel.org/io-uring/20211230173126.174350-1-ammar.faizi@intel.com/ Link: https://github.com/axboe/liburing/issues/397 [1] Link: https://lore.kernel.org/io-uring/a2399c89-2c45-375c-7395-b5caf556ec3d@kernel.dk/ [2] Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> ---
Ammar Faizi (3): io_uring: Rename `io_{send,recv}` to `io_{sendto,recvfrom}` net: Make `move_addr_to_user()` be a non static function io_uring: Add `sendto(2)` and `recvfrom(2)` support
fs/io_uring.c | 94 +++++++++++++++++++++++++++++++---- include/linux/socket.h | 2 + include/uapi/linux/io_uring.h | 5 +- net/socket.c | 4 +- 4 files changed, 92 insertions(+), 13 deletions(-)
base-commit: c1537fd063e2f1dbd96d8f68b405a66297ee306f -- 2.32.0
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