While mounting the gfs2 filesystem,our test team had a problem and we
got this error message.
=======================================================

GFS2: fsid=: Trying to join cluster "lock_nolock", "dasde1"
GFS2: fsid=dasde1.0: Joined cluster. Now mounting FS...
GFS2: not a GFS2 filesystem
GFS2: fsid=dasde1.0: can't read superblock: -22

==========================================================================
On debugging further we found that problem is while reading the super
block(gfs2_read_super) and comparing the magic number in it.
When I  replace the submit_bio() call(present in gfs2_read_super) with
the sb_getblk() and ll_rw_block(), mount operation succeded.
On further analysis we found that before calling submit_bio(),
bio->bi_sector was set to "sector" variable. This "sector" variable has
the same value of bh->b_blocknr(block number). Hence there is a need to
multiply this valuwith (blocksize >> 9)(9 because,sector size
2^9,samething happens in ll_rw_block also, before calling submit_bio()).
So I have developed the patch which solves this problem. Please let me
know your comments.
================================================================

Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>