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| author | Jens Axboe <axboe@kernel.dk> | 2024-04-01 11:27:33 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-04-01 11:41:50 -0600 |
| commit | 2a975d426c82ff05ec1f0b773798d909fe4a3105 (patch) | |
| tree | 9d10f7202d77fd15722ceefa880a9640d1457a78 /io_uring | |
| parent | 39cd87c4eb2b893354f3b850f916353f2658ae6f (diff) | |
| download | linux-2a975d426c82ff05ec1f0b773798d909fe4a3105.tar.gz linux-2a975d426c82ff05ec1f0b773798d909fe4a3105.tar.bz2 linux-2a975d426c82ff05ec1f0b773798d909fe4a3105.zip | |
io_uring/rw: don't allow multishot reads without NOWAIT support
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>
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 0585ebcc9773..c8d48287439e 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -937,6 +937,13 @@ 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. */ @@ -955,7 +962,7 @@ 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. |