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[Qemu-block] [PULL for-2.8 12/13] block/curl: Do not wait for data beyon
From: |
Jeff Cody |
Subject: |
[Qemu-block] [PULL for-2.8 12/13] block/curl: Do not wait for data beyond EOF |
Date: |
Mon, 14 Nov 2016 23:14:50 -0500 |
From: Max Reitz <address@hidden>
libcurl will only give us as much data as there is, not more. The block
layer will deny requests beyond the end of file for us; but since this
block driver is still using a sector-based interface, we can still get
in trouble if the file size is not a multiple of 512.
While we have already made sure not to attempt transfers beyond the end
of the file, we are currently still trying to receive data from there if
the original request exceeds the file size. This patch fixes this issue
and invokes qemu_iovec_memset() on the iovec's tail.
Cc: address@hidden
Signed-off-by: Max Reitz <address@hidden>
Message-id: address@hidden
Signed-off-by: Jeff Cody <address@hidden>
---
block/curl.c | 32 +++++++++++++++++++++++---------
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/block/curl.c b/block/curl.c
index 273f329..0404c1b 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -252,8 +252,17 @@ static size_t curl_read_cb(void *ptr, size_t size, size_t
nmemb, void *opaque)
continue;
if ((s->buf_off >= acb->end)) {
+ size_t request_length = acb->nb_sectors * BDRV_SECTOR_SIZE;
+
qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
acb->end - acb->start);
+
+ if (acb->end - acb->start < request_length) {
+ size_t offset = acb->end - acb->start;
+ qemu_iovec_memset(acb->qiov, offset, 0,
+ request_length - offset);
+ }
+
acb->common.cb(acb->common.opaque, 0);
qemu_aio_unref(acb);
s->acb[i] = NULL;
@@ -270,6 +279,8 @@ static int curl_find_buf(BDRVCURLState *s, size_t start,
size_t len,
{
int i;
size_t end = start + len;
+ size_t clamped_end = MIN(end, s->len);
+ size_t clamped_len = clamped_end - start;
for (i=0; i<CURL_NUM_STATES; i++) {
CURLState *state = &s->states[i];
@@ -284,12 +295,15 @@ static int curl_find_buf(BDRVCURLState *s, size_t start,
size_t len,
// Does the existing buffer cover our section?
if ((start >= state->buf_start) &&
(start <= buf_end) &&
- (end >= state->buf_start) &&
- (end <= buf_end))
+ (clamped_end >= state->buf_start) &&
+ (clamped_end <= buf_end))
{
char *buf = state->orig_buf + (start - state->buf_start);
- qemu_iovec_from_buf(acb->qiov, 0, buf, len);
+ qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
+ if (clamped_len < len) {
+ qemu_iovec_memset(acb->qiov, clamped_len, 0, len -
clamped_len);
+ }
acb->common.cb(acb->common.opaque, 0);
return FIND_RET_OK;
@@ -299,13 +313,13 @@ static int curl_find_buf(BDRVCURLState *s, size_t start,
size_t len,
if (state->in_use &&
(start >= state->buf_start) &&
(start <= buf_fend) &&
- (end >= state->buf_start) &&
- (end <= buf_fend))
+ (clamped_end >= state->buf_start) &&
+ (clamped_end <= buf_fend))
{
int j;
acb->start = start - state->buf_start;
- acb->end = acb->start + len;
+ acb->end = acb->start + clamped_len;
for (j=0; j<CURL_NUM_ACB; j++) {
if (!state->acb[j]) {
@@ -798,13 +812,13 @@ static void curl_readv_bh_cb(void *p)
}
acb->start = 0;
- acb->end = (acb->nb_sectors * BDRV_SECTOR_SIZE);
+ acb->end = MIN(acb->nb_sectors * BDRV_SECTOR_SIZE, s->len - start);
state->buf_off = 0;
g_free(state->orig_buf);
state->buf_start = start;
- state->buf_len = acb->end + s->readahead_size;
- end = MIN(start + state->buf_len, s->len) - 1;
+ state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
+ end = start + state->buf_len - 1;
state->orig_buf = g_try_malloc(state->buf_len);
if (state->buf_len && state->orig_buf == NULL) {
curl_clean_state(state);
--
2.7.4
- [Qemu-block] [PULL for-2.8 02/13] blockjob: add .clean property, (continued)
- [Qemu-block] [PULL for-2.8 02/13] blockjob: add .clean property, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 03/13] blockjob: add .start field, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 04/13] blockjob: add block_job_start, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 05/13] blockjob: refactor backup_start as backup_job_create, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 06/13] iotests: add transactional failure race test, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 07/13] qemu-iotests: avoid spurious failure on test 109, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 08/13] block/curl: Drop TFTP "support", Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 09/13] block/curl: Use BDRV_SECTOR_SIZE, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 10/13] block/curl: Fix return value from curl_read_cb, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 11/13] block/curl: Remember all sockets, Jeff Cody, 2016/11/14
- [Qemu-block] [PULL for-2.8 12/13] block/curl: Do not wait for data beyond EOF,
Jeff Cody <=
- [Qemu-block] [PULL for-2.8 13/13] mirror: do not flush every time the disks are synced, Jeff Cody, 2016/11/14
- Re: [Qemu-block] [PULL for-2.8 00/13] Block patches for 2.8, Stefan Hajnoczi, 2016/11/15