chiark / gitweb /
gpt-auto-generator: exit immediately if in container
[elogind.git] / src / gpt-auto-generator / gpt-auto-generator.c
index 0c7635bfe40e753646e4ddcff44a75a77a54d7cf..d2b4213af2ebafaba55170a515623fdae795fc8d 100644 (file)
 #include <unistd.h>
 #include <stdlib.h>
 #include <fcntl.h>
-#include <linux/btrfs.h>
 #include <sys/ioctl.h>
 #include <sys/statfs.h>
 #include <blkid.h>
 
+#ifdef HAVE_LINUX_BTRFS_H
+#include <linux/btrfs.h>
+#endif
+
 #include "path-util.h"
 #include "util.h"
 #include "mkdir.h"
 #include "libudev.h"
 #include "special.h"
 #include "unit-name.h"
+#include "virt.h"
 
 /* TODO:
  *
  * - Properly handle cryptsetup partitions
  * - Define new partition type for encrypted swap
+ * - Make /home automount rather than mount
  *
  */
 
 static const char *arg_dest = "/tmp";
 
-static int verify_gpt_partition(dev_t dev, sd_id128_t *type, unsigned *nr, char **fstype) {
-        _cleanup_free_ char *t = NULL;
-        blkid_probe b = NULL;
+static inline void blkid_free_probep(blkid_probe *b) {
+        if (*b)
+                blkid_free_probe(*b);
+}
+#define _cleanup_blkid_freep_probe_ _cleanup_(blkid_free_probep)
+
+static int verify_gpt_partition(const char *node, sd_id128_t *type, unsigned *nr, char **fstype) {
+        _cleanup_blkid_freep_probe_ blkid_probe b = NULL;
         const char *v;
         int r;
 
-        r = asprintf(&t, "/dev/block/%u:%u", major(dev), minor(dev));
-        if (r < 0)
-                return -ENOMEM;
-
         errno = 0;
-        b = blkid_new_probe_from_filename(t);
-        if (!b) {
-                if (errno != 0)
-                        return -errno;
-
-                return -ENOMEM;
-        }
+        b = blkid_new_probe_from_filename(node);
+        if (!b)
+                return errno != 0 ? -errno : -ENOMEM;
 
         blkid_probe_enable_superblocks(b, 1);
         blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
@@ -71,36 +73,27 @@ static int verify_gpt_partition(dev_t dev, sd_id128_t *type, unsigned *nr, char
 
         errno = 0;
         r = blkid_do_safeprobe(b);
-        if (r == -2) {
-                r = -ENODEV;
-                goto finish;
-        } else if (r == 1) {
-                r = -ENODEV;
-                goto finish;
-        } else if (r != 0) {
-                r = errno ? -errno : -EIO;
-                goto finish;
-        }
+        if (r == -2)
+                return -ENODEV;
+        else if (r == 1)
+                return -ENODEV;
+        else if (r != 0)
+                return errno ? -errno : -EIO;
 
         errno = 0;
         r = blkid_probe_lookup_value(b, "PART_ENTRY_SCHEME", &v, NULL);
-        if (r != 0) {
-                r = errno ? -errno : -EIO;
-                goto finish;
-        }
+        if (r != 0)
+                /* return 0 if we're not on GPT */
+                return errno ? -errno : 0;
 
-        if (strcmp(v, "gpt") != 0) {
-                r = 0;
-                goto finish;
-        }
+        if (strcmp(v, "gpt") != 0)
+                return 0;
 
         if (type) {
                 errno = 0;
                 r = blkid_probe_lookup_value(b, "PART_ENTRY_TYPE", &v, NULL);
-                if (r != 0) {
-                        r = errno ? -errno : -EIO;
-                        goto finish;
-                }
+                if (r != 0)
+                        return errno ? -errno : -EIO;
 
                 r = sd_id128_from_string(v, type);
                 if (r < 0)
@@ -110,10 +103,8 @@ static int verify_gpt_partition(dev_t dev, sd_id128_t *type, unsigned *nr, char
         if (nr) {
                 errno = 0;
                 r = blkid_probe_lookup_value(b, "PART_ENTRY_NUMBER", &v, NULL);
-                if (r != 0) {
-                        r = errno ? -errno : -EIO;
-                        goto finish;
-                }
+                if (r != 0)
+                        return errno ? -errno : -EIO;
 
                 r = safe_atou(v, nr);
                 if (r < 0)
@@ -130,22 +121,14 @@ static int verify_gpt_partition(dev_t dev, sd_id128_t *type, unsigned *nr, char
                         *fstype = NULL;
                 else {
                         fst = strdup(v);
-                        if (!fst) {
-                                r = -ENOMEM;
-                                goto finish;
-                        }
+                        if (!fst)
+                                return -ENOMEM;
 
                         *fstype = fst;
                 }
         }
 
         return 1;
-
-finish:
-        if (b)
-                blkid_free_probe(b);
-
-        return r;
 }
 
 static int add_swap(const char *path, const char *fstype) {
@@ -174,7 +157,7 @@ static int add_swap(const char *path, const char *fstype) {
                 "DefaultDependencies=no\n"
                 "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
                 "Before=" SPECIAL_UMOUNT_TARGET " " SPECIAL_SWAP_TARGET "\n\n"
-                "[Mount]\n"
+                "[Swap]\n"
                 "What=%s\n",
                 path);
 
@@ -201,6 +184,9 @@ static int add_home(const char *path, const char *fstype) {
         _cleanup_free_ char *unit = NULL, *lnk = NULL;
         _cleanup_fclose_ FILE *f = NULL;
 
+        if (dir_is_empty("/home") <= 0)
+                return 0;
+
         log_debug("Adding home: %s %s", path, fstype);
 
         unit = strappend(arg_dest, "/home.mount");
@@ -247,8 +233,7 @@ static int add_home(const char *path, const char *fstype) {
         return 0;
 }
 
-static int enumerate_partitions(dev_t dev) {
-        struct udev *udev;
+static int enumerate_partitions(struct udev *udev, dev_t dev) {
         struct udev_enumerate *e = NULL;
         struct udev_device *parent = NULL, *d = NULL;
         struct udev_list_entry *first, *item;
@@ -256,10 +241,6 @@ static int enumerate_partitions(dev_t dev) {
         _cleanup_free_ char *home = NULL, *home_fstype = NULL;
         int r;
 
-        udev = udev_new();
-        if (!udev)
-                return log_oom();
-
         e = udev_enumerate_new(udev);
         if (!e) {
                 r = log_oom();
@@ -292,7 +273,8 @@ static int enumerate_partitions(dev_t dev) {
 
         r = udev_enumerate_scan_devices(e);
         if (r < 0) {
-                log_error("Failed to enumerate partitions: %s", strerror(-r));
+                log_error("Failed to enumerate partitions on /dev/block/%u:%u: %s",
+                          major(dev), minor(dev), strerror(-r));
                 goto finish;
         }
 
@@ -322,9 +304,10 @@ static int enumerate_partitions(dev_t dev) {
                         goto finish;
                 }
 
-                r = verify_gpt_partition(udev_device_get_devnum(q), &type_id, &nr, &fstype);
+                r = verify_gpt_partition(node, &type_id, &nr, &fstype);
                 if (r < 0) {
-                        log_error("Failed to verify GPT partition: %s", strerror(-r));
+                        log_error("Failed to verify GPT partition %s: %s",
+                                  node, strerror(-r));
                         udev_device_unref(q);
                         goto finish;
                 }
@@ -365,8 +348,6 @@ finish:
         if (e)
                 udev_enumerate_unref(e);
 
-        if (udev)
-                udev_unref(udev);
 
         return r;
 }
@@ -439,19 +420,56 @@ static int get_block_device(const char *path, dev_t *dev) {
         if (statfs("/", &sfs) < 0)
                 return -errno;
 
-        if (F_TYPE_CMP(sfs.f_type, BTRFS_SUPER_MAGIC))
+        if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC))
                 return get_btrfs_block_device(path, dev);
 
         return 0;
 }
 
+static int devno_to_devnode(struct udev *udev, dev_t devno, char **ret) {
+        struct udev_device *d = NULL;
+        const char *t;
+        char *n;
+        int r;
+
+        d = udev_device_new_from_devnum(udev, 'b', devno);
+        if (!d) {
+                r = log_oom();
+                goto finish;
+        }
+
+        t = udev_device_get_devnode(d);
+        if (!t) {
+                r = -ENODEV;
+                goto finish;
+        }
+
+        n = strdup(t);
+        if (!n) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        *ret = n;
+        r = 0;
+
+finish:
+        if (d)
+                udev_device_unref(d);
+
+        return r;
+}
+
 int main(int argc, char *argv[]) {
-        dev_t dev;
+        _cleanup_free_ char *node = NULL;
+        struct udev *udev = NULL;
+        dev_t devno;
         int r;
 
         if (argc > 1 && argc != 4) {
                 log_error("This program takes three or no arguments.");
-                return EXIT_FAILURE;
+                r = -EINVAL;
+                goto finish;
         }
 
         if (argc > 1)
@@ -463,30 +481,55 @@ int main(int argc, char *argv[]) {
 
         umask(0022);
 
-        if (in_initrd())
-                return EXIT_SUCCESS;
+        if (in_initrd()) {
+                log_debug("In initrd, exiting.");
+                r = 0;
+                goto finish;
+        }
 
-        r = get_block_device("/", &dev);
+        if (detect_container(NULL) > 0) {
+                log_debug("In a container, exiting.");
+                r = 0;
+                goto finish;
+        }
+
+        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;
+                goto finish;
         }
         if (r == 0) {
                 log_debug("Root file system not on a (single) block device.");
-                return EXIT_SUCCESS;
+                goto finish;
         }
 
-        log_debug("Root device %u:%u.", major(dev), minor(dev));
+        udev = udev_new();
+        if (!udev) {
+                r = log_oom();
+                goto finish;
+        }
 
-        r = verify_gpt_partition(dev, NULL, NULL, NULL);
+        r = devno_to_devnode(udev, devno, &node);
         if (r < 0) {
-                log_error("Failed to verify GPT partition: %s", strerror(-r));
-                return EXIT_FAILURE;
+                log_error("Failed to determine block device node from major/minor: %s", strerror(-r));
+                goto finish;
+        }
+
+        log_debug("Root device %s.", node);
+
+        r = verify_gpt_partition(node, NULL, NULL, NULL);
+        if (r < 0) {
+                log_error("Failed to verify GPT partition %s: %s", node, strerror(-r));
+                goto finish;
         }
         if (r == 0)
-                return EXIT_SUCCESS;
+                goto finish;
+
+        r = enumerate_partitions(udev, devno);
 
-        r = enumerate_partitions(dev);
+finish:
+        if (udev)
+                udev_unref(udev);
 
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }