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| author | Jens Axboe <axboe@kernel.dk> | 2020-02-20 09:56:08 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-03-02 14:04:24 -0700 |
| commit | 29de5f6a350778a621a748cecc7efbb8f0cfa5a7 (patch) | |
| tree | ed72ae7e02d2c1d77877e8a2f1b614500222da1e /fs/io_uring.c | |
| parent | 80ad894382bf1d73eb688c29714fa10c0afcf2e7 (diff) | |
| download | lwn-29de5f6a350778a621a748cecc7efbb8f0cfa5a7.tar.gz lwn-29de5f6a350778a621a748cecc7efbb8f0cfa5a7.zip | |
io_uring: consider any io_read/write -EAGAIN as final
If the -EAGAIN happens because of a static condition, then a poll
or later retry won't fix it. We must call it again from blocking
condition. Play it safe and ensure that any -EAGAIN condition from read
or write must retry from async context.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 6a595c13e108..64b4519aabf8 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2234,7 +2234,7 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt, /* Ensure we clear previously set non-block flag */ if (!force_nonblock) - req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT; + kiocb->ki_flags &= ~IOCB_NOWAIT; req->result = 0; io_size = ret; @@ -2245,10 +2245,8 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt, * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so * we know to async punt it even if it was opened O_NONBLOCK */ - if (force_nonblock && !io_file_supports_async(req->file)) { - req->flags |= REQ_F_MUST_PUNT; + if (force_nonblock && !io_file_supports_async(req->file)) goto copy_iov; - } iov_count = iov_iter_count(&iter); ret = rw_verify_area(READ, req->file, &kiocb->ki_pos, iov_count); @@ -2269,6 +2267,9 @@ copy_iov: inline_vecs, &iter); if (ret) goto out_free; + /* any defer here is final, must blocking retry */ + if (!(req->flags & REQ_F_NOWAIT)) + req->flags |= REQ_F_MUST_PUNT; return -EAGAIN; } } @@ -2334,10 +2335,8 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt, * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so * we know to async punt it even if it was opened O_NONBLOCK */ - if (force_nonblock && !io_file_supports_async(req->file)) { - req->flags |= REQ_F_MUST_PUNT; + if (force_nonblock && !io_file_supports_async(req->file)) goto copy_iov; - } /* file path doesn't support NOWAIT for non-direct_IO */ if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) && @@ -2382,6 +2381,8 @@ copy_iov: inline_vecs, &iter); if (ret) goto out_free; + /* any defer here is final, must blocking retry */ + req->flags |= REQ_F_MUST_PUNT; return -EAGAIN; } } |