[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 39/47] nbd/server: Don't complain on certain client disconnects
From: |
Michael Roth |
Subject: |
[PATCH 39/47] nbd/server: Don't complain on certain client disconnects |
Date: |
Tue, 14 Dec 2021 18:01:17 -0600 |
From: Eric Blake <eblake@redhat.com>
When a client disconnects abruptly, but did not have any pending
requests (for example, when using nbdsh without calling h.shutdown),
we used to output the following message:
$ qemu-nbd -f raw file
$ nbdsh -u 'nbd://localhost:10809' -c 'h.trim(1,0)'
qemu-nbd: Disconnect client, due to: Failed to read request: Unexpected
end-of-file before all bytes were read
Then in commit f148ae7, we refactored nbd_receive_request() to use
nbd_read_eof(); when this returns 0, we regressed into tracing
uninitialized memory (if tracing is enabled) and reporting a
less-specific:
qemu-nbd: Disconnect client, due to: Request handling failed in intermediate
state
Note that with Unix sockets, we have yet another error message,
unchanged by the 6.0 regression:
$ qemu-nbd -k /tmp/sock -f raw file
$ nbdsh -u 'nbd+unix:///?socket=/tmp/sock' -c 'h.trim(1,0)'
qemu-nbd: Disconnect client, due to: Failed to send reply: Unable to write to
socket: Broken pipe
But in all cases, the error message goes away if the client performs a
soft shutdown by using NBD_CMD_DISC, rather than a hard shutdown by
abrupt disconnect:
$ nbdsh -u 'nbd://localhost:10809' -c 'h.trim(1,0)' -c 'h.shutdown()'
This patch fixes things to avoid uninitialized memory, and in general
avoids warning about a client that does a hard shutdown when not in
the middle of a packet. A client that aborts mid-request, or which
does not read the full server's reply, can still result in warnings,
but those are indeed much more unusual situations.
CC: qemu-stable@nongnu.org
Fixes: f148ae7d36 ("nbd/server: Quiesce coroutines on context switch", v6.0.0)
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: defer unrelated typo fixes to later patch]
Message-Id: <20211117170230.1128262-2-eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 1644cccea5c71b02b9cf8f78b780e7069a29b189)
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
nbd/server.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/nbd/server.c b/nbd/server.c
index 3927f7789d..83aeed51c7 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1413,6 +1413,9 @@ static int nbd_receive_request(NBDClient *client,
NBDRequest *request,
if (ret < 0) {
return ret;
}
+ if (ret == 0) {
+ return -EIO;
+ }
/* Request
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
--
2.25.1
- [PATCH 30/47] target-i386: mmu: fix handling of noncanonical virtual addresses, (continued)
- [PATCH 30/47] target-i386: mmu: fix handling of noncanonical virtual addresses, Michael Roth, 2021/12/14
- [PATCH 02/47] target/arm: Don't skip M-profile reset entirely in user mode, Michael Roth, 2021/12/14
- [PATCH 31/47] hw/scsi/scsi-disk: MODE_PAGE_ALLS not allowed in MODE SELECT commands, Michael Roth, 2021/12/14
- [PATCH 32/47] hw: m68k: virt: Add compat machine for 6.1, Michael Roth, 2021/12/14
- [PATCH 33/47] rcu: Introduce force_rcu notifier, Michael Roth, 2021/12/14
- [PATCH 34/47] accel/tcg: Register a force_rcu notifier, Michael Roth, 2021/12/14
- [PATCH 35/47] pcie: rename 'native-hotplug' to 'x-native-hotplug', Michael Roth, 2021/12/14
- [PATCH 36/47] virtio: use virtio accessor to access packed descriptor flags, Michael Roth, 2021/12/14
- [PATCH 37/47] virtio: use virtio accessor to access packed event, Michael Roth, 2021/12/14
- [PATCH 38/47] vfio: Fix memory leak of hostwin, Michael Roth, 2021/12/14
- [PATCH 39/47] nbd/server: Don't complain on certain client disconnects,
Michael Roth <=
- [PATCH 40/47] hw/nvme: fix buffer overrun in nvme_changed_nslist (CVE-2021-3947), Michael Roth, 2021/12/14
- [PATCH 03/47] virtio-net: fix use after unmap/free for sg, Michael Roth, 2021/12/14
- [PATCH 41/47] chardev/wctable: don't free the instance in wctablet_chr_finalize, Michael Roth, 2021/12/14
- [PATCH 42/47] hw/block/fdc: Extract blk_create_empty_drive(), Michael Roth, 2021/12/14
- [PATCH 43/47] hw/block/fdc: Kludge missing floppy drive to fix CVE-2021-20196, Michael Roth, 2021/12/14
- [PATCH 44/47] tests/qtest/fdc-test: Add a regression test for CVE-2021-20196, Michael Roth, 2021/12/14
- [PATCH 45/47] virtio-blk: Fix clean up of host notifiers for single MR transaction., Michael Roth, 2021/12/14
- [PATCH 46/47] net: vmxnet3: validate configuration values during activate (CVE-2021-20203), Michael Roth, 2021/12/14
- [PATCH 47/47] e1000: fix tx re-entrancy problem, Michael Roth, 2021/12/14
- [PATCH 04/47] qemu-nbd: Change default cache mode to writeback, Michael Roth, 2021/12/14