From: Jens Axboe axboe@kernel.dk
[ Upstream commit 7b9762a5e8837b92a027d58d396a9d27f6440c36 ]
io_uring supports using offset == -1 for using the current file position, and we read that in as part of read/write command setup. For the non-iter read/write types we pass in NULL for the position pointer, but for the iter types we should not be passing any anything but 0 for the position for a stream.
Clear kiocb->ki_pos if the file is a stream, don't leave it as -1. If we do, then the request will error with -ESPIPE.
Fixes: ba04291eb66e ("io_uring: allow use of offset == -1 to mean file position") Link: https://github.com/axboe/liburing/discussions/501 Reported-by: Samuel Williams samuel.williams@oriontransfer.co.nz Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- fs/io_uring.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c index e9b06e339c4b0..0006fc7479ca3 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2879,9 +2879,13 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, req->flags |= REQ_F_ISREG;
kiocb->ki_pos = READ_ONCE(sqe->off); - if (kiocb->ki_pos == -1 && !(file->f_mode & FMODE_STREAM)) { - req->flags |= REQ_F_CUR_POS; - kiocb->ki_pos = file->f_pos; + if (kiocb->ki_pos == -1) { + if (!(file->f_mode & FMODE_STREAM)) { + req->flags |= REQ_F_CUR_POS; + kiocb->ki_pos = file->f_pos; + } else { + kiocb->ki_pos = 0; + } } kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); kiocb->ki_flags = iocb_flags(kiocb->ki_filp);