tree ae0c664340718615b9c8470605a8f7c3fbe884fa
parent 0df1f2487d2f0d04703f142813d53615d62a1da4
author Darrick J. Wong <darrick.wong@oracle.com> 1417479743 -0800
committer Theodore Ts'o <tytso@mit.edu> 1417489026 -0500

jbd2: fix regression where we fail to initialize checksum seed when loading

When we're enabling journal features, we cannot use the predicate
jbd2_journal_has_csum_v2or3() because we haven't yet set the sb
feature flag fields!  Moreover, we just finished loading the shash
driver, so the test is unnecessary; calculate the seed always.

Without this patch, we fail to initialize the checksum seed the first
time we turn on journal_checksum, which means that all journal blocks
written during that first mount are corrupt.  Transactions written
after the second mount will be fine, since the feature flag will be
set in the journal superblock.  xfstests generic/{034,321,322} are the
regression tests.

(This is important for 3.18.)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.coM>
Reported-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>