tags 385951 + patch
thanks
On Mon, Sep 04, 2006 at 10:41:16AM +0200, martin f krafft wrote:
> Neil, this one looks like a bug, not sure how to fix it though.
> Maybe prevent scanning /dev/hdX if you are also scanning /dev/hdXY ?
The attached patch does just that -- if it finds hda1 right after hda (and
the major numbers match), it simply kills hda, as it can't contain both a
partition table _and_ an MD superblock. The parsing might be a bit cursory,
but I've verified the assumptions done against the kernel, so I'm quite sure
it shouldn't break. I haven't got a setup that breaks like the submitter, but
it does indeed remove hda from the scanning in my test.
Klaus Ethgen wrote:
>> This is a very critical bug and should be fixed in etch (I think, this
>> is release critical!!!)
FWIW, I'm not the maintainer, but I do not really think this warrants the
critical severity; the setup is quite rare and easily worked around (just
specify the devices manually in mdadm.conf).
/* Steinar */
--
Homepage: http://www.sesse.net/
diff -ur mdadm-2.5.3.git200608202239/config.c
mdadm-2.5.3.git200608202239.patched/config.c
--- mdadm-2.5.3.git200608202239/config.c 2006-08-21 01:27:43.000000000
+0200
+++ mdadm-2.5.3.git200608202239.patched/config.c 2006-09-13
02:33:18.000000000 +0200
@@ -222,7 +222,8 @@
mddev_dev_t load_partitions(void)
{
FILE *f = fopen("/proc/partitions", "r");
- char buf[1024];
+ char buf[1024], last_device_name[1024];
+ int last_major = -1;
mddev_dev_t rv = NULL;
if (f == NULL) {
fprintf(stderr, Name ": cannot open /proc/partitions\n");
@@ -230,7 +231,7 @@
}
while (fgets(buf, 1024, f)) {
int major, minor;
- char *name, *mp;
+ char *name, *kernel_name, *mp, *ptr;
mddev_dev_t d;
buf[1023] = '\0';
@@ -244,6 +245,46 @@
name = map_dev(major, minor, 1);
if (!name)
continue;
+
+ /*
+ * We want the name exactly as it comes from
+ * /proc/partitions; this makes sure we do not get
+ * confused by weird LVM names and the like.
+ */
+ kernel_name = buf + 22; /* will be safe until we reach
10TB */
+ while (isdigit(*kernel_name) || isspace(*kernel_name)) { /*
just to be sure */
+ ++kernel_name;
+ }
+
+ /* Chop the trailing newline. */
+ ptr = strchr(kernel_name, '\n');
+ if (ptr)
+ *ptr = '\0';
+
+ /*
+ * Check if this could be a partition of the previous device
+ * (the disk _always_ comes just before the first partition, cf.
+ * /usr/src/linux/fs/partitions/check.c)
+ */
+ if (major == last_major && strlen(kernel_name) >
strlen(last_device_name) &&
+ strncmp(kernel_name, last_device_name,
strlen(last_device_name)) == 0 &&
+ isdigit(kernel_name[strlen(kernel_name) - 1])) {
+ /*
+ * The previous device has a partition table, so delete
+ * it so it isn't scanned for a superblock. This makes
+ * sure we don't get confused when a partition with an
+ * md superblock lives very close to the end of a
+ * disk.
+ */
+ d = rv->next;
+ free(rv->devname);
+ free(rv);
+ rv = d;
+ }
+
+ last_major = major;
+ strcpy(last_device_name, kernel_name);
+
d = malloc(sizeof(*d));
d->devname = strdup(name);
d->next = rv;
