[PATCH] Fix journal detection on HFS+.

[Warren Turkal <wt@penguintechs.org>]

The code was unconditionally assumming that the volume had a jounal if the
jounal attribute was set in the volume header. However, the volume also has to
have a non-zero journal info block to actually have a journal.

Signed-off-by: Warren Turkal <wt@penguintechs.org>
---
 fs/hfsplus/super.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index eb74531..b12e767 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -260,7 +260,8 @@ static int hfsplus_remount(struct super_block *sb, int *flags, char *data)
 			printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
 			sb->s_flags |= MS_RDONLY;
 			*flags |= MS_RDONLY;
-		} else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED)) {
+		} else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED) &&
+				vhdr->journal_info_block != cpu_to_be32(0)) {
 			printk(KERN_WARNING "hfs: filesystem is marked journaled, leaving read-only.\n");
 			sb->s_flags |= MS_RDONLY;
 			*flags |= MS_RDONLY;
@@ -356,7 +357,9 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
 	} else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
 		printk(KERN_WARNING "hfs: Filesystem is marked locked, mounting read-only.\n");
 		sb->s_flags |= MS_RDONLY;
-	} else if ((vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED)) && !(sb->s_flags & MS_RDONLY)) {
+	} else if ((vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED)) &&
+			(be32_to_cpu(vhdr->journal_info_block) != 0) &&
+			!(sb->s_flags & MS_RDONLY)) {
 		printk(KERN_WARNING "hfs: write access to a journaled filesystem is not supported, "
 		       "use the force option at your own risk, mounting read-only.\n");
 		sb->s_flags |= MS_RDONLY;
-- 
1.5.6.3