From 0fef948363f62494d779cf9dc3c0a86ea1e5f7cd Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 26 Aug 2020 10:36:20 -0600 Subject: [PATCH] io_uring: make offset == -1 consistent with preadv2/pwritev2 The man page for io_uring generally claims were consistent with what preadv2 and pwritev2 accept, but turns out there's a slight discrepancy in how offset == -1 is handled for pipes/streams. preadv doesn't allow it, but preadv2 does. This currently causes io_uring to return -EINVAL if that is attempted, but we should allow that as documented. This change makes us consistent with preadv2/pwritev2 for just passing in a NULL ppos for streams if the offset is -1. Cc: stable@vger.kernel.org # v5.7+ Reported-by: Benedikt Ames Signed-off-by: Jens Axboe --- fs/io_uring.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index d9b88644d5e8..bd2d8de3f2e8 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2866,6 +2866,11 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req, return iov_iter_count(&req->io->rw.iter); } +static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) +{ + return kiocb->ki_filp->f_mode & FMODE_STREAM ? NULL : &kiocb->ki_pos; +} + /* * For files that don't have ->read_iter() and ->write_iter(), handle them * by looping over ->read() or ->write() manually. @@ -2901,10 +2906,10 @@ static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb, if (rw == READ) { nr = file->f_op->read(file, iovec.iov_base, - iovec.iov_len, &kiocb->ki_pos); + iovec.iov_len, io_kiocb_ppos(kiocb)); } else { nr = file->f_op->write(file, iovec.iov_base, - iovec.iov_len, &kiocb->ki_pos); + iovec.iov_len, io_kiocb_ppos(kiocb)); } if (iov_iter_is_bvec(iter)) @@ -3139,7 +3144,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, goto copy_iov; iov_count = iov_iter_count(iter); - ret = rw_verify_area(READ, req->file, &kiocb->ki_pos, iov_count); + ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), iov_count); if (unlikely(ret)) goto out_free; @@ -3262,7 +3267,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, goto copy_iov; iov_count = iov_iter_count(iter); - ret = rw_verify_area(WRITE, req->file, &kiocb->ki_pos, iov_count); + ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), iov_count); if (unlikely(ret)) goto out_free; -- 2.11.0