diff options
| author | Jens Axboe <axboe@kernel.dk> | 2024-04-01 20:27:33 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-10 17:38:16 +0300 |
| commit | 7dc1ed215b07d9ea06cb1bb1b42f803d8cb1a2a9 (patch) | |
| tree | c2f088c86a02a2a0c8f3de12600589d0114a5459 /io_uring | |
| parent | da64e0edbb1bd6524b5287be834f31e074409986 (diff) | |
| download | linux-7dc1ed215b07d9ea06cb1bb1b42f803d8cb1a2a9.tar.xz | |
io_uring/rw: don't allow multishot reads without NOWAIT support
commit 2a975d426c82ff05ec1f0b773798d909fe4a3105 upstream.
Supporting multishot reads requires support for NOWAIT, as the
alternative would be always having io-wq execute the work item whenever
the poll readiness triggered. Any fast file type will have NOWAIT
support (eg it understands both O_NONBLOCK and IOCB_NOWAIT). If the
given file type does not, then simply resort to single shot execution.
Cc: stable@vger.kernel.org
Fixes: fc68fcda04910 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/rw.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/io_uring/rw.c b/io_uring/rw.c index 2b84ce8a8a67..dd6fe3b328f4 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -938,6 +938,13 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) ret = __io_read(req, issue_flags); /* + * If the file doesn't support proper NOWAIT, then disable multishot + * and stay in single shot mode. + */ + if (!io_file_supports_nowait(req)) + req->flags &= ~REQ_F_APOLL_MULTISHOT; + + /* * If we get -EAGAIN, recycle our buffer and just let normal poll * handling arm it. */ @@ -956,7 +963,7 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) /* * Any successful return value will keep the multishot read armed. */ - if (ret > 0) { + if (ret > 0 && req->flags & REQ_F_APOLL_MULTISHOT) { /* * Put our buffer and post a CQE. If we fail to post a CQE, then * jump to the termination path. This request is then done. |