From 3db604b907323b8df0fc810216f6112056d26a02 Mon Sep 17 00:00:00 2001 From: Lennart Poettering 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 880661e27..ca54925da 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; } -- 2.30.2