[PATCH 2/2] Fix journal detection on HFS+.

[Warren Turkal <wt@penguintechs.org>]

The code currently mounts an HFS+ volume read-only (unless given the "force"
mount option) if it detects that the HFS+ volume has a journal. The code was
unconditionally assuming that the volume had a jounal if the journal
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.

In this patch, I refactored the journal detection into a function since the
logic is used twice. The journal detection also uses the better logic to
determine if there is a journal.

Signed-off-by: Warren Turkal <wt@penguintechs.org>
---
 fs/hfsplus/super.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index eb74531..4f00a84 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -15,10 +15,17 @@
 #include <linux/vfs.h>
 #include <linux/nls.h>
 
+#include "hfsplus_fs.h"
+
 static struct inode *hfsplus_alloc_inode(struct super_block *sb);
 static void hfsplus_destroy_inode(struct inode *inode);
+static bool hfsplus_vol_has_journal(struct hfsplus_vh *vhdr);
 
-#include "hfsplus_fs.h"
+static bool hfsplus_vol_has_journal(struct hfsplus_vh *vhdr)
+{
+	return (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED) &&
+				vhdr->journal_info_block);
+}
 
 struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
 {
@@ -260,7 +267,7 @@ 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 (hfsplus_vol_has_journal(vhdr)) {
 			printk(KERN_WARNING "hfs: filesystem is marked journaled, leaving read-only.\n");
 			sb->s_flags |= MS_RDONLY;
 			*flags |= MS_RDONLY;
@@ -356,7 +363,7 @@ 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 (hfsplus_vol_has_journal(vhdr) && !(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