There are several regressions in commit "[fs] gfs2: Implement iomap for block_map", which are fixed in mainline commit "Fixes to "Implement iomap for block_map"".
Because mainline commit "Fixes to "Implement iomap for block_map"" depends on commit "gfs2: Clean up {lookup,fillup}_metapath", backport that as well. The regressions trigger a WARN_ON(iomap.length == 0) in iomap_apply in mainline. This WARN_ON hasn't been backported to RHEL7 yet, so in order to have a reasonable reproducer, backport that patch as well. Andreas Gruenbacher (2): gfs2: Clean up {lookup,fillup}_metapath gfs2: Fixes to "Implement iomap for block_map" Darrick J. Wong (1): iomap: warn on zero-length mappings fs/gfs2/bmap.c | 117 ++++++++++++++++++++++++++------------------------------- fs/iomap.c | 2 + 2 files changed, 55 insertions(+), 64 deletions(-) -- 2.14.3