discover/status: Use full URL in parse status message

[petitboot] / discover / devmapper.c

diff --git a/discover/devmapper.c b/discover/devmapper.c
index d3179f14e7fcc52c9eb71e487ac80250e44fbf05..c1a5492b98a6550da0de04f30be4c4df952f4c0c 100644 (file)
--- a/discover/devmapper.c
+++ b/discover/devmapper.c
@@ -4,6 +4,10 @@
 #include <errno.h>
 #include <string.h>
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
 #include "libdevmapper.h"
 #include "devmapper.h"
 #include "platform.h"
@@ -17,27 +21,91 @@ struct target {
        char            *params;
 };
 
-/* Return the number of sectors on a block device. Zero represents an error */
-static uint64_t get_block_sectors(struct discover_device *device)
+static unsigned long read_param_uint(struct discover_device *device,
+                               const char *param)
 {
-       unsigned long long sectors;
+       unsigned long value = 0;
        const char *tmp;
 
-       tmp = discover_device_get_param(device, "ID_PART_ENTRY_SIZE");
+       tmp = discover_device_get_param(device, param);
        if (!tmp) {
-               pb_debug("Could not retrieve ID_PART_ENTRY_SIZE for %s\n",
+               pb_debug("Could not retrieve parameter '%s' for %s\n",
+                        param, device->device_path);
+               errno = EINVAL;
+       } else {
+               errno = 0;
+               value = strtoul(tmp, NULL, 0);
+       }
+
+       /* Return errno and result directly */
+       return value;
+}
+
+/* Return the number of sectors on a block device. Zero represents an error */
+static uint64_t get_block_sectors(struct discover_device *device)
+{
+       unsigned long major, minor, sectors = 0;
+       char *attr, *buf = NULL;
+       struct stat sb;
+       int fd = -1;
+       ssize_t sz;
+
+       sectors = read_param_uint(device, "ID_PART_ENTRY_SIZE");
+       if (!errno)
+               return (uint64_t)sectors;
+       else
+               pb_debug("Error reading sector count for %s: %m\n",
                       device->device_path);
+
+       /* Either the udev property is missing or we failed to parse it.
+        * Instead try to directly read the size attribute out of sysfs */
+       major = read_param_uint(device, "MAJOR");
+       if (errno) {
+               pb_debug("Error reading %s major number\n", device->device_path);
+               return 0;
+       }
+       minor = read_param_uint(device, "MINOR");
+       if (errno) {
+               pb_debug("Error reading %s minor number\n", device->device_path);
                return 0;
        }
 
-       errno = 0;
-       sectors = strtoull(tmp, NULL, 0);
+       attr = talloc_asprintf(device, "/sys/dev/block/%lu:%lu/size",
+                              major, minor);
+       if (stat(attr, &sb)) {
+               pb_debug("Failed to stat %s, %m\n", attr);
+               goto out;
+       }
+
+       fd = open(attr, O_RDONLY);
+       if (fd < 0) {
+               pb_debug("Failed to open sysfs attribute for %s\n",
+                        device->device_path);
+               goto out;
+       }
+
+       buf = talloc_array(device, char, sb.st_size);
+       if (!buf) {
+               pb_debug("Failed to allocate space for attr\n");
+               goto out;
+       }
+
+       sz = read(fd, buf, sb.st_size);
+       if (sz <= 0) {
+               pb_debug("Failed to read sysfs attr: %m\n");
+               goto out;
+       }
+
+       sectors = strtoul(buf, NULL, 0);
        if (errno) {
-               pb_debug("Error reading sector count for %s: %s\n",
-                      device->device_path, strerror(errno));
+               pb_debug("Failed to read sectors from sysfs: %m\n");
                sectors = 0;
        }
 
+out:
+       close(fd);
+       talloc_free(buf);
+       talloc_free(attr);
        return (uint64_t)sectors;
 }