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| author | Jens Axboe <axboe@kernel.dk> | 2022-03-18 20:28:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:23:10 +0300 |
| commit | 109dda45102112799e507a65e375ebb096d3ae49 (patch) | |
| tree | a51d119c638e002218544c61674218f2523c06c7 /fs/io_uring.c | |
| parent | 1323976e9448ace3af334235e4e0c1858119e782 (diff) | |
| download | linux-109dda45102112799e507a65e375ebb096d3ae49.tar.xz | |
io_uring: terminate manual loop iterator loop correctly for non-vecs
[ Upstream commit 5e929367468c8f97cd1ffb0417316cecfebef94b ]
The fix for not advancing the iterator if we're using fixed buffers is
broken in that it can hit a condition where we don't terminate the loop.
This results in io-wq looping forever, asking to read (or write) 0 bytes
for every subsequent loop.
Reported-by: Joel Jaeschke <joel.jaeschke@gmail.com>
Link: https://github.com/axboe/liburing/issues/549
Fixes: 16c8d2df7ec0 ("io_uring: ensure symmetry in handling iter types in loop_rw_iter()")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 70e85f64dc38..ec0b50940405 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3319,13 +3319,15 @@ static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter) ret = nr; break; } + ret += nr; if (!iov_iter_is_bvec(iter)) { iov_iter_advance(iter, nr); } else { - req->rw.len -= nr; req->rw.addr += nr; + req->rw.len -= nr; + if (!req->rw.len) + break; } - ret += nr; if (nr != iovec.iov_len) break; } |