tree b3ad6c5011d31cb72e770259a2a22889b962b2fc
parent 1f3c785c3adb7d2b109ec7c8f10081d1294b03d3
author Dave Chinner <dchinner@redhat.com> 1349754652 +1100
committer Ben Myers <bpm@sgi.com> 1352394537 -0600

xfs: growfs: don't read garbage for new secondary superblocks

When updating new secondary superblocks in a growfs operation, the
superblock buffer is read from the newly grown region of the
underlying device. This is not guaranteed to be zero, so violates
the underlying assumption that the unused parts of superblocks are
zero filled. Get a new buffer for these secondary superblocks to
ensure that the unused regions are zero filled correctly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>