From cb6800ec93c7d49f5f43355fef44f6797759cc0a Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 17 Sep 2013 18:04:40 -0500
Subject: [PATCH] gpt-auto-generator: do not assume that /dev/block/%u:%u is
useable
The generator might run before udev, and udev sets up the /dev/block/
symlinks, hence we cannot use them from the gpt generator. Instead,
manually translate a major/minor to a device node.
---
src/gpt-auto-generator/gpt-auto-generator.c | 109 +++++++++++++++++++---------
1 file changed, 74 insertions(+), 35 deletions(-)
diff --git a/src/gpt-auto-generator/gpt-auto-generator.c b/src/gpt-auto-generator/gpt-auto-generator.c
index 880661e..ca54925 100644
--- a/src/gpt-auto-generator/gpt-auto-generator.c
+++ b/src/gpt-auto-generator/gpt-auto-generator.c
@@ -55,18 +55,13 @@ static inline void blkid_free_probep(blkid_probe *b) {
}
#define _cleanup_blkid_freep_probe_ _cleanup_(blkid_free_probep)
-static int verify_gpt_partition(dev_t dev, sd_id128_t *type, unsigned *nr, char **fstype) {
- _cleanup_free_ char *t = NULL;
+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);
+ b = blkid_new_probe_from_filename(node);
if (!b)
return errno != 0 ? -errno : -ENOMEM;
@@ -237,8 +232,7 @@ 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;
@@ -246,10 +240,6 @@ 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();
@@ -294,7 +284,6 @@ static int enumerate_partitions(dev_t dev) {
struct udev_device *q;
sd_id128_t type_id;
unsigned nr;
- dev_t sub;
q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
if (!q) {
@@ -314,12 +303,10 @@ static int enumerate_partitions(dev_t dev) {
goto finish;
}
- sub = udev_device_get_devnum(q);
-
- r = verify_gpt_partition(sub, &type_id, &nr, &fstype);
+ r = verify_gpt_partition(node, &type_id, &nr, &fstype);
if (r < 0) {
- log_error("Failed to verify GPT partition /dev/block/%u:%u: %s",
- major(sub), minor(sub), strerror(-r));
+ log_error("Failed to verify GPT partition %s: %s",
+ node, strerror(-r));
udev_device_unref(q);
goto finish;
}
@@ -360,8 +347,6 @@ finish:
if (e)
udev_enumerate_unref(e);
- if (udev)
- udev_unref(udev);
return r;
}
@@ -440,13 +425,50 @@ static int get_block_device(const char *path, dev_t *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)
@@ -458,31 +480,48 @@ int main(int argc, char *argv[]) {
umask(0022);
- if (in_initrd())
- return EXIT_SUCCESS;
+ if (in_initrd()) {
+ r = 0;
+ goto finish;
+ }
- r = get_block_device("/", &dev);
+ 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;
+ }
+
+ udev = udev_new();
+ if (!udev) {
+ r = log_oom();
+ goto finish;
+ }
+
+ r = devno_to_devnode(udev, devno, &node);
+ if (r < 0) {
+ log_error("Failed to determine block device node from major/minor: %s", strerror(-r));
+ goto finish;
}
- log_debug("Root device /dev/block/%u:%u.", major(dev), minor(dev));
+ log_debug("Root device %s.", node);
- r = verify_gpt_partition(dev, NULL, NULL, NULL);
+ r = verify_gpt_partition(node, NULL, NULL, NULL);
if (r < 0) {
- log_error("Failed to verify GPT partition /dev/block/%u:%u: %s",
- major(dev), minor(dev), strerror(-r));
- return EXIT_FAILURE;
+ 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;
}