we currently do not check if a sector is allocated during convert.
This means if a sector is unallocated that we allocate a bounce
buffer of zeroes, find out its zero later and do not write it
in the best case. In the worst case this can lead to reading
blocks from a raw device (like iSCSI) altough we could easily
know via get_block_status that they are zero and simply skip them.
This patch also fixes the progress output not being at 100% after
a successful conversion.
Signed-off-by: Peter Lieven <address@hidden>
---
qemu-img.c | 85 ++++++++++++++++++++++++++++++++++--------------------------
1 file changed, 48 insertions(+), 37 deletions(-)
diff --git a/qemu-img.c b/qemu-img.c
index dc0c2f0..efb744c 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1125,13 +1125,15 @@ out3:
static int img_convert(int argc, char **argv)
{
- int c, ret = 0, n, n1, bs_n, bs_i, compress, cluster_size,
+ int c, n, n1, bs_n, bs_i, compress, cluster_size,
cluster_sectors, skip_create;
+ int64_t ret = 0;
int progress = 0, flags;
const char *fmt, *out_fmt, *cache, *out_baseimg, *out_filename;
BlockDriver *drv, *proto_drv;
BlockDriverState **bs = NULL, *out_bs = NULL;
- int64_t total_sectors, nb_sectors, sector_num, bs_offset;
+ int64_t total_sectors, nb_sectors, sector_num, bs_offset,
+ sector_num_next_status = 0;
uint64_t bs_sectors;
uint8_t * buf = NULL;
const uint8_t *buf1;
@@ -1140,7 +1142,6 @@ static int img_convert(int argc, char **argv)
QEMUOptionParameter *out_baseimg_param;
char *options = NULL;
const char *snapshot_name = NULL;
- float local_progress = 0;
int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */
bool quiet = false;
Error *local_err = NULL;
@@ -1403,10 +1404,6 @@ static int img_convert(int argc, char **argv)
sector_num = 0;
nb_sectors = total_sectors;
- if (nb_sectors != 0) {
- local_progress = (float)100 /
- (nb_sectors / MIN(nb_sectors, cluster_sectors));
- }
for(;;) {
int64_t bs_num;
@@ -1464,7 +1461,7 @@ static int img_convert(int argc, char **argv)
}
}
sector_num += n;
- qemu_progress_print(local_progress, 100);
+ qemu_progress_print(100.0 * sector_num / total_sectors, 0);
}
/* signal EOF to align */
bdrv_write_compressed(out_bs, 0, NULL, 0);
@@ -1481,21 +1478,13 @@ static int img_convert(int argc, char **argv)
sector_num = 0; // total number of sectors converted so far
nb_sectors = total_sectors - sector_num;
- if (nb_sectors != 0) {
- local_progress = (float)100 /
- (nb_sectors / MIN(nb_sectors, IO_BUF_SIZE / 512));
- }
for(;;) {
nb_sectors = total_sectors - sector_num;
if (nb_sectors <= 0) {
+ ret = 0;
break;
}
- if (nb_sectors >= (IO_BUF_SIZE / 512)) {
- n = (IO_BUF_SIZE / 512);
- } else {
- n = nb_sectors;
- }
while (sector_num - bs_offset >= bs_sectors) {
bs_i ++;
@@ -1507,34 +1496,53 @@ static int img_convert(int argc, char **argv)
sector_num, bs_i, bs_offset, bs_sectors); */
}
- if (n > bs_offset + bs_sectors - sector_num) {
- n = bs_offset + bs_sectors - sector_num;
- }
-
- /* If the output image is being created as a copy on write image,
- assume that sectors which are unallocated in the input image
- are present in both the output's and input's base images (no
- need to copy them). */
- if (out_baseimg) {
- ret = bdrv_is_allocated(bs[bs_i], sector_num - bs_offset,
- n, &n1);
+ if ((out_baseimg || has_zero_init) &&
+ sector_num >= sector_num_next_status) {
+ n = nb_sectors > INT_MAX ? INT_MAX : nb_sectors;
+ ret = bdrv_get_block_status(bs[bs_i], sector_num - bs_offset,
+ n, &n1);
if (ret < 0) {
- error_report("error while reading metadata for sector "
- "%" PRId64 ": %s",
- sector_num - bs_offset, strerror(-ret));
+ error_report("error while reading block status of sector %"
+ PRId64 ": %s", sector_num - bs_offset,
+ strerror(-ret));
goto out;
}
- if (!ret) {
+ /* If the output image is zero initialized, we are not working
+ * on a shared base and the input is zero we can skip the next
+ * n1 sectors */
+ if (has_zero_init && !out_baseimg && ret & BDRV_BLOCK_ZERO) {