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authorLennart Poettering <lennart@poettering.net>2014-03-07 04:31:26 +0100
committerLennart Poettering <lennart@poettering.net>2014-03-07 04:31:26 +0100
commit73b80ec2d999c45ce13f3e034704249d80829f7e (patch)
treea7ef3de874917e6b7d0c72bc74b2dd5b40480733 /src/gpt-auto-generator/gpt-auto-generator.c
parent329f7803ee4414cd015e6f83a835079208608171 (diff)
gpt-auto-generator: automatically find the root disk of the system
When run in an initrd and no root= argument is set (or is set to root=gpt-auto) we will automatically look for the root partition on the same disk the EFI ESP is located on. Since we look for swap, /home and /srv on the disk the root partition is located on, we hence have a fully discoverable chain: Firmware discovers the EFI ESP partition → the initrd discovers the root partition → the host OS discovers swap, /home, and /srv. Note that this requires an EFI boot loader that sets the LoaderDevicePartUUID EFI variable, such as Gummiboot.
Diffstat (limited to 'src/gpt-auto-generator/gpt-auto-generator.c')
-rw-r--r--src/gpt-auto-generator/gpt-auto-generator.c235
1 files changed, 172 insertions, 63 deletions
diff --git a/src/gpt-auto-generator/gpt-auto-generator.c b/src/gpt-auto-generator/gpt-auto-generator.c
index 3b7bc212d9..e4ce48ca9b 100644
--- a/src/gpt-auto-generator/gpt-auto-generator.c
+++ b/src/gpt-auto-generator/gpt-auto-generator.c
@@ -43,8 +43,12 @@
#include "generator.h"
#include "gpt.h"
#include "fileio.h"
+#include "efivars.h"
static const char *arg_dest = "/tmp";
+static bool arg_enabled = true;
+static bool arg_root_enabled = true;
+static bool arg_root_rw = false;
DEFINE_TRIVIAL_CLEANUP_FUNC(blkid_probe, blkid_free_probe);
#define _cleanup_blkid_freep_probe_ _cleanup_(blkid_free_probep)
@@ -287,7 +291,15 @@ static int add_cryptsetup(const char *id, const char *what, char **device) {
return 0;
}
-static int add_mount(const char *id, const char *what, const char *where, const char *fstype, const char *description) {
+static int add_mount(
+ const char *id,
+ const char *what,
+ const char *where,
+ const char *fstype,
+ const char *options,
+ const char *description,
+ const char *post) {
+
_cleanup_free_ char *unit = NULL, *lnk = NULL, *crypto_what = NULL, *p = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
@@ -295,7 +307,6 @@ static int add_mount(const char *id, const char *what, const char *where, const
assert(id);
assert(what);
assert(where);
- assert(fstype);
assert(description);
if (path_is_mount_point(where, true) <= 0 &&
@@ -304,9 +315,9 @@ static int add_mount(const char *id, const char *what, const char *where, const
return 0;
}
- log_debug("Adding %s: %s %s", where, what, fstype);
+ log_debug("Adding %s: %s %s", where, what, strna(fstype));
- if (streq(fstype, "crypto_LUKS")) {
+ if (streq_ptr(fstype, "crypto_LUKS")) {
r = add_cryptsetup(id, what, &crypto_what);
if (r < 0)
@@ -337,6 +348,9 @@ static int add_mount(const char *id, const char *what, const char *where, const
"Documentation=man:systemd-gpt-auto-generator(8)\n",
description);
+ if (post)
+ fprintf(f, "Before=%s\n", post);
+
r = generator_write_fsck_deps(f, arg_dest, what, where, fstype);
if (r < 0)
return r;
@@ -348,26 +362,28 @@ static int add_mount(const char *id, const char *what, const char *where, const
"Where=%s\n",
what, where);
- if (fstype) {
- fprintf(f,
- "Type=%s\n",
- fstype);
- }
+ if (fstype)
+ fprintf(f, "Type=%s\n", fstype);
+
+ if (options)
+ fprintf(f, "Options=%s\n", options);
fflush(f);
if (ferror(f)) {
- log_error("Failed to write unit file %s: %m", unit);
+ log_error("Failed to write unit file %s: %m", p);
return -errno;
}
- lnk = strjoin(arg_dest, "/" SPECIAL_LOCAL_FS_TARGET ".requires/", unit, NULL);
- if (!lnk)
- return log_oom();
+ if (post) {
+ lnk = strjoin(arg_dest, "/", post, ".requires/", unit, NULL);
+ if (!lnk)
+ return log_oom();
- mkdir_parents_label(lnk, 0755);
- if (symlink(unit, lnk) < 0) {
- log_error("Failed to create symlink %s: %m", lnk);
- return -errno;
+ mkdir_parents_label(lnk, 0755);
+ if (symlink(p, lnk) < 0) {
+ log_error("Failed to create symlink %s: %m", lnk);
+ return -errno;
+ }
}
return 0;
@@ -380,7 +396,7 @@ static int enumerate_partitions(struct udev *udev, dev_t dev) {
unsigned home_nr = (unsigned) -1, srv_nr = (unsigned )-1;
struct udev_list_entry *first, *item;
struct udev_device *parent = NULL;
- int r;
+ int r, k;
e = udev_enumerate_new(udev);
if (!e)
@@ -408,6 +424,8 @@ static int enumerate_partitions(struct udev *udev, dev_t dev) {
return r;
}
+ r = 0;
+
first = udev_enumerate_get_list_entry(e);
udev_list_entry_foreach(item, first) {
_cleanup_udev_device_unref_ struct udev_device *q;
@@ -430,21 +448,26 @@ static int enumerate_partitions(struct udev *udev, dev_t dev) {
if (!node)
return log_oom();
- r = verify_gpt_partition(node, &type_id, &nr, &fstype);
- if (r < 0) {
+ k = verify_gpt_partition(node, &type_id, &nr, &fstype);
+ if (k < 0) {
/* skip child devices which are not detected properly */
- if (r == -EBADSLT)
+ if (k == -EBADSLT)
continue;
- log_error("Failed to verify GPT partition %s: %s", node, strerror(-r));
- return r;
+
+ log_error("Failed to verify GPT partition %s: %s", node, strerror(-k));
+ r = k;
+ continue;
}
- if (r == 0)
+ if (k == 0)
continue;
- if (sd_id128_equal(type_id, GPT_SWAP))
- add_swap(node, fstype);
+ if (sd_id128_equal(type_id, GPT_SWAP)) {
+
+ k = add_swap(node, fstype);
+ if (k < 0)
+ r = k;
- else if (sd_id128_equal(type_id, GPT_HOME)) {
+ } else if (sd_id128_equal(type_id, GPT_HOME)) {
/* We only care for the first /home partition */
if (home && nr >= home_nr)
@@ -480,11 +503,17 @@ static int enumerate_partitions(struct udev *udev, dev_t dev) {
}
}
- if (home && home_fstype)
- add_mount("home", home, "/home", home_fstype, "Home Partition");
+ if (home && home_fstype) {
+ k = add_mount("home", home, "/home", home_fstype, NULL, "Home Partition", SPECIAL_LOCAL_FS_TARGET);
+ if (k < 0)
+ r = k;
+ }
- if (srv && srv_fstype)
- add_mount("srv", srv, "/srv", srv_fstype, "Server Data Partition");
+ if (srv && srv_fstype) {
+ k = add_mount("srv", srv, "/srv", srv_fstype, NULL, "Server Data Partition", SPECIAL_LOCAL_FS_TARGET);
+ if (k < 0)
+ r = k;
+ }
return r;
}
@@ -582,55 +611,95 @@ static int devno_to_devnode(struct udev *udev, dev_t devno, char **ret) {
return 0;
}
-int main(int argc, char *argv[]) {
- _cleanup_udev_unref_ struct udev *udev = NULL;
- _cleanup_free_ char *node = NULL;
- dev_t devno;
- int r = 0;
+static int parse_proc_cmdline_item(const char *key, const char *value) {
+ int r;
- if (argc > 1 && argc != 4) {
- log_error("This program takes three or no arguments.");
- return EXIT_FAILURE;
- }
+ assert(key);
- if (argc > 1)
- arg_dest = argv[3];
+ if (STR_IN_SET(key, "systemd.gpt_auto", "rd.systemd.gpt_auto") && value) {
- log_set_target(LOG_TARGET_SAFE);
- log_parse_environment();
- log_open();
+ r = parse_boolean(value);
+ if (r < 0)
+ log_warning("Failed to parse gpt-auto switch %s. Ignoring.", value);
- umask(0022);
+ arg_enabled = r;
- if (in_initrd()) {
- log_debug("In initrd, exiting.");
- return EXIT_SUCCESS;
+ } else if (streq(key, "root") && value) {
+
+ /* Disable root disk logic if there's a root= value
+ * specified (unless it happens to be "gpt-auto") */
+
+ arg_root_enabled = streq(value, "gpt-auto");
+
+ } else if (streq(key, "rw") && !value)
+ arg_root_rw = true;
+ else if (streq(key, "ro") && !value)
+ arg_root_rw = false;
+ else if (startswith(key, "systemd.gpt-auto.") || startswith(key, "rd.systemd.gpt-auto."))
+ log_warning("Unknown kernel switch %s. Ignoring.", key);
+
+ return 0;
+}
+
+static int add_root_mount(void) {
+
+#ifdef ENABLE_EFI
+ int r;
+
+ if (!is_efi_boot()) {
+ log_debug("Not a EFI boot, not creating root mount.");
+ return 0;
}
- if (detect_container(NULL) > 0) {
- log_debug("In a container, exiting.");
- return EXIT_SUCCESS;
+ r = efi_loader_get_device_part_uuid(NULL);
+ if (r == -ENOENT) {
+ log_debug("EFI loader partition unknown, exiting.");
+ return 0;
+ } else if (r < 0) {
+ log_error("Failed to read ESP partition UUID: %s", strerror(-r));
+ return r;
}
+ /* OK, we have an ESP partition, this is fantastic, so let's
+ * wait for a root device to show up. A udev rule will create
+ * the link for us under the right name. */
+
+ return add_mount(
+ "root",
+ "/dev/disk/by-id/gpt-auto-root",
+ in_initrd() ? "/sysroot" : "/",
+ NULL,
+ arg_root_rw ? "rw" : "ro",
+ "Root Partition",
+ in_initrd() ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_LOCAL_FS_TARGET);
+#else
+ return 0;
+#endif
+}
+
+static int add_mounts(void) {
+ _cleanup_udev_unref_ struct udev *udev = NULL;
+ _cleanup_free_ char *node = NULL;
+ dev_t devno;
+ int r;
+
r = get_block_device("/", &devno);
if (r < 0) {
log_error("Failed to determine block device of root file system: %s", strerror(-r));
- return EXIT_FAILURE;
+ return r;
} else if (r == 0) {
log_debug("Root file system not on a (single) block device.");
- return EXIT_SUCCESS;
+ return 0;
}
udev = udev_new();
- if (!udev) {
- log_oom();
- return EXIT_FAILURE;
- }
+ if (!udev)
+ return log_oom();
r = devno_to_devnode(udev, devno, &node);
if (r < 0) {
log_error("Failed to determine block device node from major/minor: %s", strerror(-r));
- return EXIT_FAILURE;
+ return r;
}
log_debug("Root device %s.", node);
@@ -638,16 +707,56 @@ int main(int argc, char *argv[]) {
r = verify_gpt_partition(node, NULL, NULL, NULL);
if (r < 0) {
log_error("Failed to verify GPT partition %s: %s", node, strerror(-r));
- return EXIT_FAILURE;
+ return r;
}
if (r == 0) {
log_debug("Not a GPT disk, exiting.");
+ return 0;
+ }
+
+ return enumerate_partitions(udev, devno);
+}
+
+int main(int argc, char *argv[]) {
+ int r = 0;
+
+ if (argc > 1 && argc != 4) {
+ log_error("This program takes three or no arguments.");
+ return EXIT_FAILURE;
+ }
+
+ if (argc > 1)
+ arg_dest = argv[3];
+
+ log_set_target(LOG_TARGET_SAFE);
+ log_parse_environment();
+ log_open();
+
+ umask(0022);
+
+ if (detect_container(NULL) > 0) {
+ log_debug("In a container, exiting.");
return EXIT_SUCCESS;
}
- r = enumerate_partitions(udev, devno);
- if (r < 0)
+ if (parse_proc_cmdline(parse_proc_cmdline_item) < 0)
return EXIT_FAILURE;
- return EXIT_SUCCESS;
+ if (!arg_enabled) {
+ log_debug("Disabled, exiting.");
+ return EXIT_SUCCESS;
+ }
+
+ if (arg_root_enabled)
+ r = add_root_mount();
+
+ if (!in_initrd()) {
+ int k;
+
+ k = add_mounts();
+ if (k < 0)
+ r = k;
+ }
+
+ return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}