tree 3142102b533bcab238ea38be2bf272f90575da75
parent b58bf407ca4669a2dfcc00f5888ee719d9c34150
author Bob Peterson <rpeterso@redhat.com> 1426085551 -0500
committer Bob Peterson <rpeterso@redhat.com> 1450117168 -0600

GFS2: Update master statfs buffer with sd_statfs_spin locked

Before this patch, function update_statfs called gfs2_statfs_change_out
to update the master statfs buffer without the sd_statfs_spin held.
In theory, another process could call gfs2_statfs_sync, which takes
the sd_statfs_spin lock and re-reads m_sc from the buffer. So there's
a theoretical timing window in which one process could write the
master statfs buffer, then another comes along and re-reads it, wiping
out the changes.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>