diff options
author | Stefan Hajnoczi <stefanha@redhat.com> | 2022-07-06 09:03:41 +0100 |
---|---|---|
committer | Stefan Hajnoczi <stefanha@redhat.com> | 2022-07-07 09:04:15 +0100 |
commit | be6a166fde652589761cf70471bcde623e9bd72a (patch) | |
tree | e1baac746a39c68813c441da727548379b76fc41 /block | |
parent | c06fc7ce147e57ab493bad9263f1601b8298484b (diff) |
block/io_uring: clarify that short reads can happen
Jens Axboe has confirmed that short reads are rare but can happen:
https://lore.kernel.org/io-uring/YsU%2FCGkl9ZXUI+Tj@stefanha-x1.localdomain/T/#m729963dc577d709b709c191922e98ec79d7eef54
The luring_resubmit_short_read() comment claimed they were only due to a
specific io_uring bug that was fixed in Linux commit 9d93a3f5a0c
("io_uring: punt short reads to async context"), which is wrong.
Dominique Martinet found that a btrfs bug also causes short reads. There
may be more kernel code paths that result in short reads.
Let's consider short reads fair game.
Cc: Dominique Martinet <dominique.martinet@atmark-techno.com>
Based-on: <20220630010137.2518851-1-dominique.martinet@atmark-techno.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20220706080341.1206476-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block')
-rw-r--r-- | block/io_uring.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/block/io_uring.c b/block/io_uring.c index b238661740..f8a19fd97f 100644 --- a/block/io_uring.c +++ b/block/io_uring.c @@ -73,12 +73,8 @@ static void luring_resubmit(LuringState *s, LuringAIOCB *luringcb) /** * luring_resubmit_short_read: * - * Before Linux commit 9d93a3f5a0c ("io_uring: punt short reads to async - * context") a buffered I/O request with the start of the file range in the - * page cache could result in a short read. Applications need to resubmit the - * remaining read request. - * - * This is a slow path but recent kernels never take it. + * Short reads are rare but may occur. The remaining read request needs to be + * resubmitted. */ static void luring_resubmit_short_read(LuringState *s, LuringAIOCB *luringcb, int nread) |