diff options
| -rw-r--r-- | qemu-img-cmds.hx | 6 | ||||
| -rw-r--r-- | qemu-img.c | 92 | ||||
| -rw-r--r-- | qemu-img.texi | 12 |
3 files changed, 110 insertions, 0 deletions
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx index f96876ae3b..c079019048 100644 --- a/qemu-img-cmds.hx +++ b/qemu-img-cmds.hx @@ -49,5 +49,11 @@ DEF("rebase", img_rebase, "rebase [-f fmt] [-u] -b backing_file [-F backing_fmt] filename") STEXI @item rebase [-f @var{fmt}] [-u] -b @var{backing_file} [-F @var{backing_fmt}] @var{filename} +ETEXI + +DEF("resize", img_resize, + "resize filename [+ | -]size") +STEXI +@item rebase @var{filename} [+ | -]@var{size} @end table ETEXI diff --git a/qemu-img.c b/qemu-img.c index 74311a5215..c21d9990e0 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1225,6 +1225,98 @@ static int img_rebase(int argc, char **argv) return 0; } +static int img_resize(int argc, char **argv) +{ + int c, ret, relative; + const char *filename, *fmt, *size; + int64_t n, total_size; + BlockDriverState *bs; + QEMUOptionParameter *param; + QEMUOptionParameter resize_options[] = { + { + .name = BLOCK_OPT_SIZE, + .type = OPT_SIZE, + .help = "Virtual disk size" + }, + { NULL } + }; + + fmt = NULL; + for(;;) { + c = getopt(argc, argv, "f:h"); + if (c == -1) { + break; + } + switch(c) { + case 'h': + help(); + break; + case 'f': + fmt = optarg; + break; + } + } + if (optind + 1 >= argc) { + help(); + } + filename = argv[optind++]; + size = argv[optind++]; + + /* Choose grow, shrink, or absolute resize mode */ + switch (size[0]) { + case '+': + relative = 1; + size++; + break; + case '-': + relative = -1; + size++; + break; + default: + relative = 0; + break; + } + + /* Parse size */ + param = parse_option_parameters("", resize_options, NULL); + if (set_option_parameter(param, BLOCK_OPT_SIZE, size)) { + /* Error message already printed when size parsing fails */ + exit(1); + } + n = get_option_parameter(param, BLOCK_OPT_SIZE)->value.n; + free_option_parameters(param); + + bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR); + + if (relative) { + total_size = bdrv_getlength(bs) + n * relative; + } else { + total_size = n; + } + if (total_size <= 0) { + error("New image size must be positive"); + } + + ret = bdrv_truncate(bs, total_size); + switch (ret) { + case 0: + printf("Image resized.\n"); + break; + case -ENOTSUP: + error("This image format does not support resize"); + break; + case -EACCES: + error("Image is read-only"); + break; + default: + error("Error resizing image (%d)", -ret); + break; + } + + bdrv_delete(bs); + return 0; +} + static const img_cmd_t img_cmds[] = { #define DEF(option, callback, arg_string) \ { option, callback }, diff --git a/qemu-img.texi b/qemu-img.texi index ac978542c2..c1b1f2717e 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -106,6 +106,18 @@ they are displayed too. @item snapshot [-l | -a @var{snapshot} | -c @var{snapshot} | -d @var{snapshot} ] @var{filename} List, apply, create or delete snapshots in image @var{filename}. + +@item resize @var{filename} [+ | -]@var{size} + +Change the disk image as if it had been created with @var{size}. + +Before using this command to shrink a disk image, you MUST use file system and +partitioning tools inside the VM to reduce allocated file systems and partition +sizes accordingly. Failure to do so will result in data loss! + +After using this command to grow a disk image, you must use file system and +partitioning tools inside the VM to actually begin using the new space on the +device. @end table Supported image file formats: |