diff --git a/man/systemd-vmspawn.xml b/man/systemd-vmspawn.xml
index 0be886cb13..2db88d3b7f 100644
--- a/man/systemd-vmspawn.xml
+++ b/man/systemd-vmspawn.xml
@@ -266,6 +266,18 @@
+
+
+
+
+ Grows the image file specified by to the specified size
+ in bytes if it is smaller. Executes no operation if no image file is used or the image file is
+ already as large or larger than requested. The specified size accepts the usual K, M, G suffixes
+ (to the base of 1024). Specified values are rounded up to multiples of 4096.
+
+
+
+
diff --git a/src/vmspawn/vmspawn.c b/src/vmspawn/vmspawn.c
index 821e08ea6a..e49d18c148 100644
--- a/src/vmspawn/vmspawn.c
+++ b/src/vmspawn/vmspawn.c
@@ -66,6 +66,7 @@
#include "stdio-util.h"
#include "string-util.h"
#include "strv.h"
+#include "sync-util.h"
#include "time-util.h"
#include "tmpfile-util.h"
#include "unit-name.h"
@@ -119,6 +120,7 @@ static char *arg_ssh_key_type = NULL;
static bool arg_discard_disk = true;
struct ether_addr arg_network_provided_mac = {};
static char **arg_smbios11 = NULL;
+static uint64_t arg_grow_image = 0;
STATIC_DESTRUCTOR_REGISTER(arg_directory, freep);
STATIC_DESTRUCTOR_REGISTER(arg_image, freep);
@@ -170,6 +172,7 @@ static int help(void) {
" --secure-boot=BOOL Enable searching for firmware supporting SecureBoot\n"
" --firmware=PATH|list Select firmware definition file (or list available)\n"
" --discard-disk=BOOL Control processing of discard requests\n"
+ " -G --grow-image=BYTES Grow image file to specified size in bytes\n"
" -s --smbios11=STRING Pass an arbitrary SMBIOS Type #11 string to the VM\n"
"\n%3$sSystem Identity:%4$s\n"
" -M --machine=NAME Set the machine name for the VM\n"
@@ -300,6 +303,7 @@ static int parse_argv(int argc, char *argv[]) {
{ "discard-disk", required_argument, NULL, ARG_DISCARD_DISK },
{ "background", required_argument, NULL, ARG_BACKGROUND },
{ "smbios11", required_argument, NULL, 's' },
+ { "grow-image", required_argument, NULL, 'G' },
{}
};
@@ -309,7 +313,7 @@ static int parse_argv(int argc, char *argv[]) {
assert(argv);
optind = 0;
- while ((c = getopt_long(argc, argv, "+hD:i:M:nqs:", options, NULL)) >= 0)
+ while ((c = getopt_long(argc, argv, "+hD:i:M:nqs:G:", options, NULL)) >= 0)
switch (c) {
case 'h':
return help();
@@ -583,6 +587,18 @@ static int parse_argv(int argc, char *argv[]) {
break;
+ case 'G':
+ if (isempty(optarg)) {
+ arg_grow_image = 0;
+ break;
+ }
+
+ r = parse_size(optarg, 1024, &arg_grow_image);
+ if (r < 0)
+ return log_error_errno(r, "Failed to parse --grow-image= paramater: %s", optarg);
+
+ break;
+
case '?':
return -EINVAL;
@@ -1465,6 +1481,47 @@ static int generate_ssh_keypair(const char *key_path, const char *key_type) {
return 0;
}
+static int grow_image(const char *path, uint64_t size) {
+ int r;
+
+ assert(path);
+
+ if (size == 0)
+ return 0;
+
+ /* Round up to multiple of 4K */
+ size = DIV_ROUND_UP(size, 4096);
+ if (size > UINT64_MAX / 4096)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Specified file size too large, refusing.");
+ size *= 4096;
+
+ _cleanup_close_ int fd = xopenat_full(AT_FDCWD, path, O_RDWR|O_CLOEXEC, XO_REGULAR, /* mode= */ 0);
+ if (fd < 0)
+ return log_error_errno(fd, "Failed to open image file '%s': %m", path);
+
+ struct stat st;
+ if (fstat(fd, &st) < 0)
+ return log_error_errno(errno, "Failed to stat '%s': %m", path);
+ if ((uint64_t) st.st_size >= size) {
+ log_debug("Not growing image '%s' to %s, size already at %s.", path,
+ FORMAT_BYTES(size), FORMAT_BYTES(st.st_size));
+ return 0;
+ }
+
+ if (ftruncate(fd, size) < 0)
+ return log_error_errno(errno, "Failed grow image file '%s' from %s to %s: %m", path,
+ FORMAT_BYTES(st.st_size), FORMAT_BYTES(size));
+
+ r = fsync_full(fd);
+ if (r < 0)
+ return log_error_errno(r, "Failed to sync image file '%s' after growing to %s: %m", path, FORMAT_BYTES(size));
+
+ if (!arg_quiet)
+ log_info("Image file '%s' successfully grown from %s to %s.", path, FORMAT_BYTES(st.st_size), FORMAT_BYTES(size));
+
+ return 1;
+}
+
static int run_virtual_machine(int kvm_device_fd, int vhost_device_fd) {
SSHInfo ssh_info; /* Used when talking to pid1 via SSH, but must survive until the function ends. */
_cleanup_(ovmf_config_freep) OvmfConfig *ovmf_config = NULL;
@@ -2156,6 +2213,10 @@ static int run_virtual_machine(int kvm_device_fd, int vhost_device_fd) {
return log_error_errno(r, "Failed to parse $SYSTEMD_VMSPAWN_QEMU_EXTRA: %m");
}
+ r = grow_image(arg_image, arg_grow_image);
+ if (r < 0)
+ return r;
+
if (DEBUG_LOGGING) {
_cleanup_free_ char *joined = quote_command_line(cmdline, SHELL_ESCAPE_EMPTY);
if (!joined)