gfs2: fix the escaped block copy in gfs2_before_commit()

Commit d68d0c6c3fc7 ("gfs2: Use memcpy_{from,to}_page where
appropriate") made the escaped buffer copy read from the mempool page
it had just allocated instead of from the buffer, so the block written
to the log is whatever the pool page last held. If the journal is
replayed after a crash, the block is restored from that and the file's
data is corrupted. Only escaped buffers are affected: jdata blocks
whose first four bytes match GFS2_MAGIC. Copy from the buffer's folio
instead.

Fixes: d68d0c6c3fc7 ("gfs2: Use memcpy_{from,to}_page where appropriate")
Cc: stable@vger.kernel.org
Signed-off-by: Tal Zussman <tz2294@columbia.edu>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

0 files changed, 0 insertions, 0 deletions