X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/a3ce3668ccff7d350a4f795ad99a012a6d41caef..325b3ceff69c987e90acf9c8ef6f55e646b39767:/qemu-img.c

diff --git a/qemu-img.c b/qemu-img.c
index 54137a4e92..6a61ca8d06 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -66,7 +66,8 @@ static void help(void)
            "  '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"
@@ -81,6 +82,8 @@ static void help(void)
            "       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"
@@ -183,27 +186,6 @@ static int read_password(char *buf, int buf_size)
 }
 #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;
@@ -350,8 +332,9 @@ static int img_create(int argc, char **argv)
     /* 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.");
@@ -445,6 +428,13 @@ static int img_check(int argc, char **argv)
         }
     }
 
+    if (result.bfi.total_clusters != 0 && result.bfi.allocated_clusters != 0) {
+        printf("%" PRId64 "/%" PRId64 "= %0.2f%% allocated, %0.2f%% fragmented\n",
+        result.bfi.allocated_clusters, result.bfi.total_clusters,
+        result.bfi.allocated_clusters * 100.0 / result.bfi.total_clusters,
+        result.bfi.fragmented_clusters * 100.0 / result.bfi.allocated_clusters);
+    }
+
     bdrv_delete(bs);
 
     if (ret < 0 || result.check_errors) {
@@ -495,7 +485,7 @@ static int img_commit(int argc, char **argv)
     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;
@@ -531,40 +521,6 @@ static int img_commit(int argc, char **argv)
     return 0;
 }
 
-/*
- * Checks whether the sector is not a zero sector.
- *
- * Attention! The len must be a multiple of 4 * sizeof(long) due to
- * restriction of optimizations in this function.
- */
-static int is_not_zero(const uint8_t *sector, int len)
-{
-    /*
-     * Use long as the biggest available internal data type that fits into the
-     * CPU register and unroll the loop to smooth out the effect of memory
-     * latency.
-     */
-
-    int i;
-    long d0, d1, d2, d3;
-    const long * const data = (const long *) sector;
-
-    len /= sizeof(long);
-
-    for(i = 0; i < len; i += 4) {
-        d0 = data[i + 0];
-        d1 = data[i + 1];
-        d2 = data[i + 2];
-        d3 = data[i + 3];
-
-        if (d0 || d1 || d2 || d3) {
-            return 1;
-        }
-    }
-
-    return 0;
-}
-
 /*
  * Returns true iff the first sector pointed to by 'buf' contains at least
  * a non-NUL byte.
@@ -574,20 +530,64 @@ static int is_not_zero(const uint8_t *sector, int len)
  */
 static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
 {
-    int v, i;
+    bool is_zero;
+    int i;
 
     if (n <= 0) {
         *pnum = 0;
         return 0;
     }
-    v = is_not_zero(buf, 512);
+    is_zero = buffer_is_zero(buf, 512);
     for(i = 1; i < n; i++) {
         buf += 512;
-        if (v != is_not_zero(buf, 512))
+        if (is_zero != buffer_is_zero(buf, 512)) {
             break;
+        }
     }
     *pnum = i;
-    return v;
+    return !is_zero;
+}
+
+/*
+ * 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;
 }
 
 /*
@@ -640,6 +640,7 @@ static int img_convert(int argc, char **argv)
     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";
@@ -647,7 +648,7 @@ static int img_convert(int argc, char **argv)
     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;
         }
@@ -682,6 +683,19 @@ static int img_convert(int argc, char **argv)
         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;
@@ -709,11 +723,11 @@ static int img_convert(int argc, char **argv)
         ret = -1;
         goto out;
     }
-        
+
     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++) {
@@ -787,6 +801,8 @@ static int img_convert(int argc, char **argv)
     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");
@@ -800,6 +816,15 @@ static int img_convert(int argc, char **argv)
             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 */
@@ -819,7 +844,7 @@ static int img_convert(int argc, char **argv)
     }
 
     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;
@@ -834,7 +859,7 @@ static int img_convert(int argc, char **argv)
     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);
@@ -890,7 +915,8 @@ static int img_convert(int argc, char **argv)
 
                 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;
                 }
 
@@ -904,12 +930,12 @@ static int img_convert(int argc, char **argv)
             if (n < cluster_sectors) {
                 memset(buf + n * 512, 0, cluster_size - n * 512);
             }
-            if (is_not_zero(buf, cluster_size)) {
+            if (!buffer_is_zero(buf, cluster_size)) {
                 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;
                 }
             }
@@ -972,7 +998,8 @@ static int img_convert(int argc, char **argv)
 
             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
@@ -988,10 +1015,11 @@ static int img_convert(int argc, char **argv)
                    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;
                     }
                 }
@@ -1006,7 +1034,7 @@ 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);
     }
@@ -1016,7 +1044,7 @@ out:
                 bdrv_delete(bs[bs_i]);
             }
         }
-        qemu_free(bs);
+        g_free(bs);
     }
     if (ret) {
         return 1;
@@ -1024,35 +1052,6 @@ out:
     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)
 {
@@ -1069,7 +1068,7 @@ 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)
@@ -1112,7 +1111,7 @@ 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 {
@@ -1133,6 +1132,9 @@ static int img_info(int argc, char **argv)
         if (bdi.cluster_size != 0) {
             printf("cluster_size: %d\n", bdi.cluster_size);
         }
+        if (bdi.is_dirty) {
+            printf("cleanly shut down: no\n");
+        }
     }
     bdrv_get_backing_filename(bs, backing_filename, sizeof(backing_filename));
     if (backing_filename[0] != '\0') {
@@ -1320,7 +1322,7 @@ static int img_rebase(int argc, char **argv)
     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;
@@ -1396,16 +1398,20 @@ static int img_rebase(int argc, char **argv)
      */
     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));
@@ -1424,16 +1430,36 @@ static int img_rebase(int argc, char **argv)
                 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 */
@@ -1459,8 +1485,8 @@ static int img_rebase(int argc, char **argv)
             qemu_progress_print(local_progress, 100);
         }
 
-        qemu_free(buf_old);
-        qemu_free(buf_new);
+        qemu_vfree(buf_old);
+        qemu_vfree(buf_new);
     }
 
     /*
@@ -1598,7 +1624,7 @@ static int img_resize(int argc, char **argv)
         printf("Image resized.\n");
         break;
     case -ENOTSUP:
-        error_report("This image format does not support resize");
+        error_report("This image does not support resize");
         break;
     case -EACCES:
         error_report("Image is read-only");
@@ -1639,6 +1665,8 @@ int main(int argc, char **argv)
     cmdname = argv[1];
     argc--; argv++;
 
+    qemu_init_main_loop();
+
     /* find the command */
     for(cmd = img_cmds; cmd->name != NULL; cmd++) {
         if (!strcmp(cmdname, cmd->name)) {