Commit 32f38691 authored Dec 01, 2014 by Darrick J. Wong Committed by Theodore Ts'o Dec 01, 2014

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>

parent 0df1f248

fs/jbd2/journal.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -1853,14 +1853,13 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
		journal->j_chksum_driver = NULL;
		return 0;
		}
		}

		/* Precompute checksum seed for all metadata */
		if (jbd2_journal_has_csum_v2or3(journal))
		journal->j_csum_seed = jbd2_chksum(journal, ~0,
		sb->s_uuid,
		sizeof(sb->s_uuid));
		}
		}

		/* If enabling v1 checksums, downgrade superblock */
		if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM))

Admin message