From 1113e1b504f6e8d4364c0b73c9097828067d4617 Mon Sep 17 00:00:00 2001 From: "Patrick J. LoPresti" Date: Thu, 22 Jul 2010 15:04:16 -0700 Subject: [PATCH] JBD2: Allow feature checks before journal recovery Before we start accessing a huge (> 16 TiB) OCFS2 volume, we need to confirm that its journal supports 64-bit offsets. In particular, we need to check the journal's feature bits before recovering the journal. This is not possible with JBD2 at present, because the journal superblock (where the feature bits reside) is not loaded from disk until the journal is recovered. This patch loads the journal superblock in jbd2_journal_check_used_features() if it has not already been loaded, allowing us to check the feature bits before journal recovery. Signed-off-by: Patrick LoPresti Cc: linux-ext4@vger.kernel.org Acked-by: "Theodore Ts'o" Signed-off-by: Joel Becker --- fs/jbd2/journal.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 0e8014ea6b94..262419f83d80 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1371,6 +1371,10 @@ int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat, if (!compat && !ro && !incompat) return 1; + /* Load journal superblock if it is not loaded yet. */ + if (journal->j_format_version == 0 && + journal_get_superblock(journal) != 0) + return 0; if (journal->j_format_version == 1) return 0; -- 2.34.1