}
/*
- * Is @optarg safe for accumulate_options()?
+ * Is @list safe for accumulate_options()?
* It is when multiple of them can be joined together separated by ','.
- * To make that work, @optarg must not start with ',' (or else a
+ * To make that work, @list must not start with ',' (or else a
* separating ',' preceding it gets escaped), and it must not end with
* an odd number of ',' (or else a separating ',' following it gets
* escaped), or be empty (or else a separating ',' preceding it can
* escape a separating ',' following it).
*
*/
-static bool is_valid_option_list(const char *optarg)
+static bool is_valid_option_list(const char *list)
{
- size_t len = strlen(optarg);
+ size_t len = strlen(list);
size_t i;
- if (!optarg[0] || optarg[0] == ',') {
+ if (!list[0] || list[0] == ',') {
return false;
}
- for (i = len; i > 0 && optarg[i - 1] == ','; i--) {
+ for (i = len; i > 0 && list[i - 1] == ','; i--) {
}
if ((len - i) % 2) {
return false;
return true;
}
-static int accumulate_options(char **options, char *optarg)
+static int accumulate_options(char **options, char *list)
{
char *new_options;
- if (!is_valid_option_list(optarg)) {
- error_report("Invalid option list: %s", optarg);
+ if (!is_valid_option_list(list)) {
+ error_report("Invalid option list: %s", list);
return -1;
}
if (!*options) {
- *options = g_strdup(optarg);
+ *options = g_strdup(list);
} else {
- new_options = g_strdup_printf("%s,%s", *options, optarg);
+ new_options = g_strdup_printf("%s,%s", *options, list);
g_free(*options);
*options = new_options;
}
}
/*
- * Compares two buffers sector by sector. Returns 0 if the first
- * sector of each buffer matches, non-zero otherwise.
+ * Compares two buffers chunk by chunk, where @chsize is the chunk size.
+ * If @chsize is 0, default chunk size of BDRV_SECTOR_SIZE is used.
+ * Returns 0 if the first chunk of each buffer matches, non-zero otherwise.
*
- * pnum is set to the sector-aligned size of the buffer prefix that
- * has the same matching status as the first sector.
+ * @pnum is set to the size of the buffer prefix aligned to @chsize that
+ * has the same matching status as the first chunk.
*/
static int compare_buffers(const uint8_t *buf1, const uint8_t *buf2,
- int64_t bytes, int64_t *pnum)
+ int64_t bytes, uint64_t chsize, int64_t *pnum)
{
bool res;
- int64_t i = MIN(bytes, BDRV_SECTOR_SIZE);
+ int64_t i;
assert(bytes > 0);
+ if (!chsize) {
+ chsize = BDRV_SECTOR_SIZE;
+ }
+ i = MIN(bytes, chsize);
+
res = !!memcmp(buf1, buf2, i);
while (i < bytes) {
- int64_t len = MIN(bytes - i, BDRV_SECTOR_SIZE);
+ int64_t len = MIN(bytes - i, chsize);
if (!!memcmp(buf1 + i, buf2 + i, len) != res) {
break;
ret = 4;
goto out;
}
- ret = compare_buffers(buf1, buf2, chunk, &pnum);
+ ret = compare_buffers(buf1, buf2, chunk, 0, &pnum);
if (ret || pnum != chunk) {
qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
offset + (ret ? 0 : pnum));
case OFORMAT_JSON:
printf("{ \"start\": %"PRId64", \"length\": %"PRId64","
" \"depth\": %"PRId64", \"present\": %s, \"zero\": %s,"
- " \"data\": %s", e->start, e->length, e->depth,
+ " \"data\": %s, \"compressed\": %s",
+ e->start, e->length, e->depth,
e->present ? "true" : "false",
e->zero ? "true" : "false",
- e->data ? "true" : "false");
+ e->data ? "true" : "false",
+ e->compressed ? "true" : "false");
if (e->has_offset) {
printf(", \"offset\": %"PRId64"", e->offset);
}
has_offset = !!(ret & BDRV_BLOCK_OFFSET_VALID);
if (file && has_offset) {
+ bdrv_graph_rdlock_main_loop();
bdrv_refresh_filename(file);
+ bdrv_graph_rdunlock_main_loop();
filename = file->filename;
}
.length = bytes,
.data = !!(ret & BDRV_BLOCK_DATA),
.zero = !!(ret & BDRV_BLOCK_ZERO),
+ .compressed = !!(ret & BDRV_BLOCK_COMPRESSED),
.offset = map,
.has_offset = has_offset,
.depth = depth,
}
if (curr->zero != next->zero ||
curr->data != next->data ||
+ curr->compressed != next->compressed ||
curr->depth != next->depth ||
curr->present != next->present ||
!curr->filename != !next->filename ||
sn.date_sec = rt / G_USEC_PER_SEC;
sn.date_nsec = (rt % G_USEC_PER_SEC) * 1000;
+ bdrv_graph_rdlock_main_loop();
ret = bdrv_snapshot_create(bs, &sn);
+ bdrv_graph_rdunlock_main_loop();
+
if (ret) {
- error_report("Could not create snapshot '%s': %d (%s)",
- snapshot_name, ret, strerror(-ret));
+ error_report("Could not create snapshot '%s': %s",
+ snapshot_name, strerror(-ret));
}
break;
break;
case SNAPSHOT_DELETE:
+ bdrv_graph_rdlock_main_loop();
ret = bdrv_snapshot_find(bs, &sn, snapshot_name);
if (ret < 0) {
error_report("Could not delete snapshot '%s': snapshot not "
ret = 1;
}
}
+ bdrv_graph_rdunlock_main_loop();
break;
}
uint8_t *buf_new = NULL;
BlockDriverState *bs = NULL, *prefix_chain_bs = NULL;
BlockDriverState *unfiltered_bs;
+ BlockDriverInfo bdi = {0};
char *filename;
const char *fmt, *cache, *src_cache, *out_basefmt, *out_baseimg;
int c, flags, src_flags, ret;
+ BdrvRequestFlags write_flags = 0;
bool writethrough, src_writethrough;
int unsafe = 0;
bool force_share = false;
int progress = 0;
bool quiet = false;
+ bool compress = false;
Error *local_err = NULL;
bool image_opts = false;
+ int64_t write_align;
/* Parse commandline parameters */
fmt = NULL;
{"object", required_argument, 0, OPTION_OBJECT},
{"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
{"force-share", no_argument, 0, 'U'},
+ {"compress", no_argument, 0, 'c'},
{0, 0, 0, 0}
};
- c = getopt_long(argc, argv, ":hf:F:b:upt:T:qU",
+ c = getopt_long(argc, argv, ":hf:F:b:upt:T:qUc",
long_options, NULL);
if (c == -1) {
break;
case 'U':
force_share = true;
break;
+ case 'c':
+ compress = true;
+ break;
}
}
unfiltered_bs = bdrv_skip_filters(bs);
+ if (compress && !block_driver_can_compress(unfiltered_bs->drv)) {
+ error_report("Compression not supported for this file format");
+ ret = -1;
+ goto out;
+ } else if (compress) {
+ write_flags |= BDRV_REQ_WRITE_COMPRESSED;
+ }
+
if (out_basefmt != NULL) {
if (bdrv_find_format(out_basefmt) == NULL) {
error_report("Invalid format name: '%s'", out_basefmt);
}
}
+ /*
+ * We need overlay subcluster size (or cluster size in case writes are
+ * compressed) to make sure write requests are aligned.
+ */
+ ret = bdrv_get_info(unfiltered_bs, &bdi);
+ if (ret < 0) {
+ error_report("could not get block driver info");
+ goto out;
+ } else if (bdi.subcluster_size == 0) {
+ bdi.cluster_size = bdi.subcluster_size = 1;
+ }
+
+ write_align = compress ? bdi.cluster_size : bdi.subcluster_size;
+
/* For safe rebasing we need to compare old and new backing file */
if (!unsafe) {
QDict *options = NULL;
qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true);
}
+ bdrv_graph_rdlock_main_loop();
bdrv_refresh_filename(bs);
+ bdrv_graph_rdunlock_main_loop();
overlay_filename = bs->exact_filename[0] ? bs->exact_filename
: bs->filename;
out_real_path =
int64_t old_backing_size = 0;
int64_t new_backing_size = 0;
uint64_t offset;
- int64_t n;
+ int64_t n, n_old = 0, n_new = 0;
float local_progress = 0;
- buf_old = blk_blockalign(blk, IO_BUF_SIZE);
- buf_new = blk_blockalign(blk, IO_BUF_SIZE);
+ if (blk_old_backing && bdrv_opt_mem_align(blk_bs(blk_old_backing)) >
+ bdrv_opt_mem_align(blk_bs(blk))) {
+ buf_old = blk_blockalign(blk_old_backing, IO_BUF_SIZE);
+ } else {
+ buf_old = blk_blockalign(blk, IO_BUF_SIZE);
+ }
+ buf_new = blk_blockalign(blk_new_backing, IO_BUF_SIZE);
size = blk_getlength(blk);
if (size < 0) {
}
for (offset = 0; offset < size; offset += n) {
- bool buf_old_is_zero = false;
+ bool old_backing_eof = false;
+ int64_t n_alloc;
/* How many bytes can we handle with the next read? */
n = MIN(IO_BUF_SIZE, size - offset);
}
if (prefix_chain_bs) {
+ uint64_t bytes = n;
+
/*
* If cluster wasn't changed since prefix_chain, we don't need
* to take action
strerror(-ret));
goto out;
}
- if (!ret) {
+ if (!ret && n) {
continue;
}
+ if (!n) {
+ /*
+ * If we've reached EOF of the old backing, it means that
+ * offsets beyond the old backing size were read as zeroes.
+ * Now we will need to explicitly zero the cluster in
+ * order to preserve that state after the rebase.
+ */
+ n = bytes;
+ }
}
+ /*
+ * At this point we know that the region [offset; offset + n)
+ * is unallocated within the target image. This region might be
+ * unaligned to the target image's (sub)cluster boundaries, as
+ * old backing may have smaller clusters (or have subclusters).
+ * We extend it to the aligned boundaries to avoid CoW on
+ * partial writes in blk_pwrite(),
+ */
+ n += offset - QEMU_ALIGN_DOWN(offset, write_align);
+ offset = QEMU_ALIGN_DOWN(offset, write_align);
+ n += QEMU_ALIGN_UP(offset + n, write_align) - (offset + n);
+ n = MIN(n, size - offset);
+ assert(!bdrv_is_allocated(unfiltered_bs, offset, n, &n_alloc) &&
+ n_alloc == n);
+
+ /*
+ * Much like with the target image, we'll try to read as much
+ * of the old and new backings as we can.
+ */
+ n_old = MIN(n, MAX(0, old_backing_size - (int64_t) offset));
+ n_new = MIN(n, MAX(0, new_backing_size - (int64_t) offset));
+
/*
* Read old and new backing file and take into consideration that
* backing files may be smaller than the COW image.
*/
- if (offset >= old_backing_size) {
- memset(buf_old, 0, n);
- buf_old_is_zero = true;
+ memset(buf_old + n_old, 0, n - n_old);
+ if (!n_old) {
+ old_backing_eof = true;
} else {
- if (offset + n > old_backing_size) {
- n = old_backing_size - offset;
- }
-
- ret = blk_pread(blk_old_backing, offset, n, buf_old, 0);
+ ret = blk_pread(blk_old_backing, offset, n_old, buf_old, 0);
if (ret < 0) {
error_report("error while reading from old backing file");
goto out;
}
}
- if (offset >= new_backing_size || !blk_new_backing) {
- memset(buf_new, 0, n);
- } else {
- if (offset + n > new_backing_size) {
- n = new_backing_size - offset;
- }
-
- ret = blk_pread(blk_new_backing, offset, n, buf_new, 0);
+ memset(buf_new + n_new, 0, n - n_new);
+ if (n_new) {
+ ret = blk_pread(blk_new_backing, offset, n_new, buf_new, 0);
if (ret < 0) {
error_report("error while reading from new backing file");
goto out;
int64_t pnum;
if (compare_buffers(buf_old + written, buf_new + written,
- n - written, &pnum))
+ n - written, write_align, &pnum))
{
- if (buf_old_is_zero) {
+ if (old_backing_eof) {
ret = blk_pwrite_zeroes(blk, offset + written, pnum, 0);
} else {
+ assert(written + pnum <= IO_BUF_SIZE);
ret = blk_pwrite(blk, offset + written, pnum,
- buf_old + written, 0);
+ buf_old + written, write_flags);
}
if (ret < 0) {
error_report("Error while writing to COW image: %s",
}
written += pnum;
+ if (offset + written >= old_backing_size) {
+ old_backing_eof = true;
+ }
}
qemu_progress_print(local_progress, 100);
}
{
BlockDriver *drv;
+ GRAPH_RDLOCK_GUARD_MAINLOOP();
+
/* Find driver and parse its options */
drv = bdrv_find_format(format);
if (!drv) {
goto out;
}
+ bdrv_graph_rdlock_main_loop();
if (!bs->drv->bdrv_amend_options) {
error_report("Format driver '%s' does not support option amendment",
fmt);
+ bdrv_graph_rdunlock_main_loop();
ret = -1;
goto out;
}
"This option is only supported for image creation\n");
}
+ bdrv_graph_rdunlock_main_loop();
error_report_err(err);
ret = -1;
goto out;
qemu_progress_print(0.f, 0);
ret = bdrv_amend_options(bs, opts, &amend_status_cb, NULL, force, &err);
qemu_progress_print(100.f, 0);
+ bdrv_graph_rdunlock_main_loop();
+
if (ret < 0) {
error_report_err(err);
goto out;
projects / mirror_qemu.git / blobdiff