" 'filename' is a disk image filename\n"
" 'fmt' is the disk image format. It is guessed automatically in most cases\n"
" 'cache' is the cache mode used to write the output disk image, the valid\n"
- " options are: 'none', 'writeback' (default), 'writethrough' and 'unsafe'\n"
+ " options are: 'none', 'writeback' (default), 'writethrough', 'directsync'\n"
+ " and 'unsafe'\n"
" 'size' is the disk image size in bytes. Optional suffixes\n"
" 'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M)\n"
" and T (terabyte, 1024G) are supported. 'b' is ignored.\n"
" rebasing in this case (useful for renaming the backing file)\n"
" '-h' with or without a command shows this help and lists the supported formats\n"
" '-p' show progress of command (only certain commands)\n"
+ " '-S' indicates the consecutive number of bytes that must contain only zeros\n"
+ " for qemu-img to create a sparse image during conversion\n"
"\n"
"Parameters to snapshot subcommand:\n"
" 'snapshot' is the name of the snapshot to create, apply or delete\n"
}
#endif
-static int set_cache_flag(const char *mode, int *flags)
-{
- *flags &= ~BDRV_O_CACHE_MASK;
-
- if (!strcmp(mode, "none") || !strcmp(mode, "off")) {
- *flags |= BDRV_O_CACHE_WB;
- *flags |= BDRV_O_NOCACHE;
- } else if (!strcmp(mode, "writeback")) {
- *flags |= BDRV_O_CACHE_WB;
- } else if (!strcmp(mode, "unsafe")) {
- *flags |= BDRV_O_CACHE_WB;
- *flags |= BDRV_O_NO_FLUSH;
- } else if (!strcmp(mode, "writethrough")) {
- /* this is the default */
- } else {
- return -1;
- }
-
- return 0;
-}
-
static int print_block_option_help(const char *filename, const char *fmt)
{
BlockDriver *drv, *proto_drv;
/* Get image size, if specified */
if (optind < argc) {
int64_t sval;
- sval = strtosz_suffix(argv[optind++], NULL, STRTOSZ_DEFSUFFIX_B);
- if (sval < 0) {
+ char *end;
+ sval = strtosz_suffix(argv[optind++], &end, STRTOSZ_DEFSUFFIX_B);
+ if (sval < 0 || *end) {
error_report("Invalid image size specified! You may use k, M, G or "
"T suffixes for ");
error_report("kilobytes, megabytes, gigabytes and terabytes.");
filename = argv[optind++];
flags = BDRV_O_RDWR;
- ret = set_cache_flag(cache, &flags);
+ ret = bdrv_parse_cache_flags(cache, &flags);
if (ret < 0) {
error_report("Invalid cache option: %s", cache);
return -1;
return v;
}
+/*
+ * Like is_allocated_sectors, but if the buffer starts with a used sector,
+ * up to 'min' consecutive sectors containing zeros are ignored. This avoids
+ * breaking up write requests for only small sparse areas.
+ */
+static int is_allocated_sectors_min(const uint8_t *buf, int n, int *pnum,
+ int min)
+{
+ int ret;
+ int num_checked, num_used;
+
+ if (n < min) {
+ min = n;
+ }
+
+ ret = is_allocated_sectors(buf, n, pnum);
+ if (!ret) {
+ return ret;
+ }
+
+ num_used = *pnum;
+ buf += BDRV_SECTOR_SIZE * *pnum;
+ n -= *pnum;
+ num_checked = num_used;
+
+ while (n > 0) {
+ ret = is_allocated_sectors(buf, n, pnum);
+
+ buf += BDRV_SECTOR_SIZE * *pnum;
+ n -= *pnum;
+ num_checked += *pnum;
+ if (ret) {
+ num_used = num_checked;
+ } else if (*pnum >= min) {
+ break;
+ }
+ }
+
+ *pnum = num_used;
+ return 1;
+}
+
/*
* Compares two buffers sector by sector. Returns 0 if the first sector of both
* buffers matches, non-zero otherwise.
char *options = NULL;
const char *snapshot_name = NULL;
float local_progress;
+ int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */
fmt = NULL;
out_fmt = "raw";
out_baseimg = NULL;
compress = 0;
for(;;) {
- c = getopt(argc, argv, "f:O:B:s:hce6o:pt:");
+ c = getopt(argc, argv, "f:O:B:s:hce6o:pS:t:");
if (c == -1) {
break;
}
case 's':
snapshot_name = optarg;
break;
+ case 'S':
+ {
+ int64_t sval;
+ char *end;
+ sval = strtosz_suffix(optarg, &end, STRTOSZ_DEFSUFFIX_B);
+ if (sval < 0 || *end) {
+ error_report("Invalid minimum zero buffer size for sparse output specified");
+ return 1;
+ }
+
+ min_sparse = sval / BDRV_SECTOR_SIZE;
+ break;
+ }
case 'p':
progress = 1;
break;
qemu_progress_init(progress, 2.0);
qemu_progress_print(0, 100);
- bs = qemu_mallocz(bs_n * sizeof(BlockDriverState *));
+ bs = g_malloc0(bs_n * sizeof(BlockDriverState *));
total_sectors = 0;
for (bs_i = 0; bs_i < bs_n; bs_i++) {
if (compress) {
QEMUOptionParameter *encryption =
get_option_parameter(param, BLOCK_OPT_ENCRYPT);
+ QEMUOptionParameter *preallocation =
+ get_option_parameter(param, BLOCK_OPT_PREALLOC);
if (!drv->bdrv_write_compressed) {
error_report("Compression not supported for this file format");
ret = -1;
goto out;
}
+
+ if (preallocation && preallocation->value.s
+ && strcmp(preallocation->value.s, "off"))
+ {
+ error_report("Compression and preallocation not supported at "
+ "the same time");
+ ret = -1;
+ goto out;
+ }
}
/* Create the new image */
}
flags = BDRV_O_RDWR;
- ret = set_cache_flag(cache, &flags);
+ ret = bdrv_parse_cache_flags(cache, &flags);
if (ret < 0) {
error_report("Invalid cache option: %s", cache);
return -1;
bs_i = 0;
bs_offset = 0;
bdrv_get_geometry(bs[0], &bs_sectors);
- buf = qemu_malloc(IO_BUF_SIZE);
+ buf = qemu_blockalign(out_bs, IO_BUF_SIZE);
if (compress) {
ret = bdrv_get_info(out_bs, &bdi);
ret = bdrv_read(bs[bs_i], bs_num, buf2, nlow);
if (ret < 0) {
- error_report("error while reading");
+ error_report("error while reading sector %" PRId64 ": %s",
+ bs_num, strerror(-ret));
goto out;
}
ret = bdrv_write_compressed(out_bs, sector_num, buf,
cluster_sectors);
if (ret != 0) {
- error_report("error while compressing sector %" PRId64,
- sector_num);
+ error_report("error while compressing sector %" PRId64
+ ": %s", sector_num, strerror(-ret));
goto out;
}
}
ret = bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n);
if (ret < 0) {
- error_report("error while reading");
+ error_report("error while reading sector %" PRId64 ": %s",
+ sector_num - bs_offset, strerror(-ret));
goto out;
}
/* NOTE: at the same time we convert, we do not write zero
sectors that are entirely 0, since whatever data was
already there is garbage, not 0s. */
if (!has_zero_init || out_baseimg ||
- is_allocated_sectors(buf1, n, &n1)) {
+ is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
ret = bdrv_write(out_bs, sector_num, buf1, n1);
if (ret < 0) {
- error_report("error while writing");
+ error_report("error while writing sector %" PRId64
+ ": %s", sector_num, strerror(-ret));
goto out;
}
}
qemu_progress_end();
free_option_parameters(create_options);
free_option_parameters(param);
- qemu_free(buf);
+ qemu_vfree(buf);
if (out_bs) {
bdrv_delete(out_bs);
}
bdrv_delete(bs[bs_i]);
}
}
- qemu_free(bs);
+ g_free(bs);
}
if (ret) {
return 1;
return 0;
}
-#ifdef _WIN32
-static int64_t get_allocated_file_size(const char *filename)
-{
- typedef DWORD (WINAPI * get_compressed_t)(const char *filename, DWORD *high);
- get_compressed_t get_compressed;
- struct _stati64 st;
-
- /* WinNT support GetCompressedFileSize to determine allocate size */
- get_compressed = (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"), "GetCompressedFileSizeA");
- if (get_compressed) {
- DWORD high, low;
- low = get_compressed(filename, &high);
- if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR)
- return (((int64_t) high) << 32) + low;
- }
-
- if (_stati64(filename, &st) < 0)
- return -1;
- return st.st_size;
-}
-#else
-static int64_t get_allocated_file_size(const char *filename)
-{
- struct stat st;
- if (stat(filename, &st) < 0)
- return -1;
- return (int64_t)st.st_blocks * 512;
-}
-#endif
static void dump_snapshots(BlockDriverState *bs)
{
sn = &sn_tab[i];
printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), sn));
}
- qemu_free(sn_tab);
+ g_free(sn_tab);
}
static int img_info(int argc, char **argv)
bdrv_get_format(bs, fmt_name, sizeof(fmt_name));
bdrv_get_geometry(bs, &total_sectors);
get_human_readable_size(size_buf, sizeof(size_buf), total_sectors * 512);
- allocated_size = get_allocated_file_size(filename);
+ allocated_size = bdrv_get_allocated_file_size(bs);
if (allocated_size < 0) {
snprintf(dsize_buf, sizeof(dsize_buf), "unavailable");
} else {
qemu_progress_print(0, 100);
flags = BDRV_O_RDWR | (unsafe ? BDRV_O_NO_BACKING : 0);
- ret = set_cache_flag(cache, &flags);
+ ret = bdrv_parse_cache_flags(cache, &flags);
if (ret < 0) {
error_report("Invalid cache option: %s", cache);
return -1;
*/
if (!unsafe) {
uint64_t num_sectors;
+ uint64_t old_backing_num_sectors;
+ uint64_t new_backing_num_sectors;
uint64_t sector;
int n;
uint8_t * buf_old;
uint8_t * buf_new;
float local_progress;
- buf_old = qemu_malloc(IO_BUF_SIZE);
- buf_new = qemu_malloc(IO_BUF_SIZE);
+ buf_old = qemu_blockalign(bs, IO_BUF_SIZE);
+ buf_new = qemu_blockalign(bs, IO_BUF_SIZE);
bdrv_get_geometry(bs, &num_sectors);
+ bdrv_get_geometry(bs_old_backing, &old_backing_num_sectors);
+ bdrv_get_geometry(bs_new_backing, &new_backing_num_sectors);
local_progress = (float)100 /
(num_sectors / MIN(num_sectors, IO_BUF_SIZE / 512));
continue;
}
- /* Read old and new backing file */
- ret = bdrv_read(bs_old_backing, sector, buf_old, n);
- if (ret < 0) {
- error_report("error while reading from old backing file");
- goto out;
+ /*
+ * Read old and new backing file and take into consideration that
+ * backing files may be smaller than the COW image.
+ */
+ if (sector >= old_backing_num_sectors) {
+ memset(buf_old, 0, n * BDRV_SECTOR_SIZE);
+ } else {
+ if (sector + n > old_backing_num_sectors) {
+ n = old_backing_num_sectors - sector;
+ }
+
+ ret = bdrv_read(bs_old_backing, sector, buf_old, n);
+ if (ret < 0) {
+ error_report("error while reading from old backing file");
+ goto out;
+ }
}
- ret = bdrv_read(bs_new_backing, sector, buf_new, n);
- if (ret < 0) {
- error_report("error while reading from new backing file");
- goto out;
+
+ if (sector >= new_backing_num_sectors) {
+ memset(buf_new, 0, n * BDRV_SECTOR_SIZE);
+ } else {
+ if (sector + n > new_backing_num_sectors) {
+ n = new_backing_num_sectors - sector;
+ }
+
+ ret = bdrv_read(bs_new_backing, sector, buf_new, n);
+ if (ret < 0) {
+ error_report("error while reading from new backing file");
+ goto out;
+ }
}
/* If they differ, we need to write to the COW file */
qemu_progress_print(local_progress, 100);
}
- qemu_free(buf_old);
- qemu_free(buf_new);
+ qemu_vfree(buf_old);
+ qemu_vfree(buf_new);
}
/*
projects / qemu.git / blobdiff