blkid: fix ZFS device detection

Fix the ZFS device detection by looking at multiple uberblocks to
see if any are present, rather than looking for the ZFS boot block
which is not always present.

There may be up to 128 uberblocks, but the first 4 are not written
to disk on a newly-formatted filesystem so check several of them at
different offsets within the uberblock array.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>

diff --git a/lib/blkid/probe.c b/lib/blkid/probe.c
index 4b797ab..161f4f1 100644 (file)
--- a/lib/blkid/probe.c
+++ b/lib/blkid/probe.c
@@ -1440,10 +1440,19 @@ static struct blkid_magic type_array[] = {
   { "iso9660", 32,      1,  5, "CD001",                probe_iso9660 },
   { "iso9660", 32,      9,  5, "CDROM",                probe_iso9660 },
   { "jfs",     32,      0,  4, "JFS1",                 probe_jfs },
-  { "zfs",       8,     0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
-  { "zfs",       8,     0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
-  { "zfs",     264,     0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
-  { "zfs",     264,     0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
+  /* ZFS has 128 root blocks (#4 is the first used), check only 6 of them */
+  { "zfs",     128,     0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     128,     0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     132,     0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     132,     0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     136,     0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     136,     0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     384,     0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     384,     0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     388,     0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     388,     0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     392,     0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     392,     0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
   { "hfsplus",  1,      0,  2, "BD",                   probe_hfsplus },
   { "hfsplus",  1,      0,  2, "H+",                   probe_hfsplus },
   { "hfsplus",  1,      0,  2, "HX",                   probe_hfsplus },