reiserfs: Fix remaining in-reclaim-fs <-> reclaim-fs-on locking inversion

Commit 500f5a0b
(reiserfs: Fix possible recursive lock) fixed a vmalloc under reiserfs
lock that triggered a lockdep warning because of a
IN-FS-RECLAIM <-> RECLAIM-FS-ON locking dependency inversion.

But this patch has ommitted another vmalloc call in the same path
that allocates the journal. Relax the lock for this one too.
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>

fs/reiserfs/journal.c

@@ -2758,11 +2758,18 @@ int journal_init(struct super_block *sb, const char *j_dev_name,
 	struct reiserfs_journal *journal;
 	struct reiserfs_journal_list *jl;
 	char b[BDEVNAME_SIZE];
+	int ret;
 
+	/*
+	 * Unlock here to avoid various RECLAIM-FS-ON <-> IN-RECLAIM-FS
+	 * dependency inversion warnings.
+	 */
+	reiserfs_write_unlock(sb);
 	journal = SB_JOURNAL(sb) = vmalloc(sizeof(struct reiserfs_journal));
 	if (!journal) {
 		reiserfs_warning(sb, "journal-1256",
 				 "unable to get memory for journal structure");
+		reiserfs_write_lock(sb);
 		return 1;
 	}
 	memset(journal, 0, sizeof(struct reiserfs_journal));
@@ -2771,10 +2778,12 @@ int journal_init(struct super_block *sb, const char *j_dev_name,
 	INIT_LIST_HEAD(&journal->j_working_list);
 	INIT_LIST_HEAD(&journal->j_journal_list);
 	journal->j_persistent_trans = 0;
-	if (reiserfs_allocate_list_bitmaps(sb,
-					   journal->j_list_bitmap,
-					   reiserfs_bmap_count(sb)))
+	ret = reiserfs_allocate_list_bitmaps(sb, journal->j_list_bitmap,
+					   reiserfs_bmap_count(sb));
+	reiserfs_write_lock(sb);
+	if (ret)
 		goto free_and_return;
+
 	allocate_bitmap_nodes(sb);
 
 	/* reserved for journal area support */