diff options
| author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2018-03-08 21:46:33 +0300 |
|---|---|---|
| committer | Eric Blake <eblake@redhat.com> | 2018-03-13 15:38:55 -0500 |
| commit | 37e02aebf88f8a12f02457de207b09b607c1e8a8 (patch) | |
| tree | be634841b12c2222eb0bca6d9826f8530dce641a /nbd | |
| parent | 60ace2bacfbadb0cfae265929024dbece1ecf9af (diff) | |
nbd/server: fix sparse read
In case of io error in nbd_co_send_sparse_read we should not
"goto reply:", as it was a fatal error and the common behavior
is to disconnect in this case. We should not try to send the
client an additional error reply, since we already hit a
channel-io error on our previous attempt to send one.
Fix this by handling block-status error in nbd_co_send_sparse_read,
so nbd_co_send_sparse_read fails only on io error. Then just skip
common "reply:" code path in nbd_trip.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180308184636.178534-3-vsementsov@virtuozzo.com>
[eblake: grammar tweaks]
Signed-off-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'nbd')
| -rw-r--r-- | nbd/server.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/nbd/server.c b/nbd/server.c index 3d0f024193..5f292064af 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1366,6 +1366,10 @@ static int coroutine_fn nbd_co_send_structured_error(NBDClient *client, return nbd_co_send_iov(client, iov, 1 + !!iov[1].iov_len, errp); } +/* Do a sparse read and send the structured reply to the client. + * Returns -errno if sending fails. bdrv_block_status_above() failure is + * reported to the client, at which point this function succeeds. + */ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, uint64_t handle, uint64_t offset, @@ -1386,8 +1390,13 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, bool final; if (status < 0) { - error_setg_errno(errp, -status, "unable to check for holes"); - return status; + char *msg = g_strdup_printf("unable to check for holes: %s", + strerror(-status)); + + ret = nbd_co_send_structured_error(client, handle, -status, msg, + errp); + g_free(msg); + return ret; } assert(pnum && pnum <= size - progress); final = progress + pnum == size; @@ -1568,7 +1577,7 @@ static coroutine_fn void nbd_trip(void *opaque) request.from, req->data, request.len, &local_err); if (ret < 0) { - goto reply; + goto replied; } goto done; } @@ -1665,6 +1674,8 @@ reply: req->data, reply_data_len, &local_err); } g_free(msg); + +replied: if (ret < 0) { error_prepend(&local_err, "Failed to send reply: "); goto disconnect; |