diff options
| author | Nicholas Thomas <nick@bytemark.co.uk> | 2011-08-15 10:00:34 +0100 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2011-08-23 17:41:14 +0200 |
| commit | f785a5ae36c92fbeb8e0e8c9d71f5789cbce8b29 (patch) | |
| tree | 77e2070775dbbe899b23f91b60e26761750968a3 /block/curl.c | |
| parent | 3fba9d8198a50f69e80aba8458d26cf1654e6e26 (diff) | |
| download | qemu-f785a5ae36c92fbeb8e0e8c9d71f5789cbce8b29.tar.gz | |
block/curl: Handle failed reads gracefully.
Current behaviour if a read fails is for the acb to not get finished.
This causes an infinite loop in bdrv_read_em (block.c). The read failure
never gets reported to the guest and if the error condition clears, the
process never recovers.
With this patch, when curl reports a failure we finish the acb as a
failure. This results in the guest receiving an I/O error (rather than
the read hanging indefinitely) and if the error condition subsequently
clears, retries work as expected.
The simplest test is to put an ISO on a web server you have control over
and open it with qemu-io. Then move the ISO out of the way and attempt
to read some data - you should see behaviour matching the above.
Signed-off-by: Nick Thomas <nick@bytemark.co.uk>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/curl.c')
| -rw-r--r-- | block/curl.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/block/curl.c b/block/curl.c index 5c157bc609..f3f61cc8a1 100644 --- a/block/curl.c +++ b/block/curl.c @@ -229,6 +229,23 @@ static void curl_multi_do(void *arg) { CURLState *state = NULL; curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, (char**)&state); + + /* ACBs for successful messages get completed in curl_read_cb */ + if (msg->data.result != CURLE_OK) { + int i; + for (i = 0; i < CURL_NUM_ACB; i++) { + CURLAIOCB *acb = state->acb[i]; + + if (acb == NULL) { + continue; + } + + acb->common.cb(acb->common.opaque, -EIO); + qemu_aio_release(acb); + state->acb[i] = NULL; + } + } + curl_clean_state(state); break; } @@ -277,7 +294,8 @@ static CURLState *curl_init_state(BDRVCURLState *s) curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1); curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1); curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg); - + curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1); + #ifdef DEBUG_VERBOSE curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1); #endif |