[PATCH 2/2] hfsplus: add mount option to enable ACL support

[Ernesto A. Fernández <ernesto.mnd.fernandez@xxxxxxxxx>]

The hfsplus module already has the code to support access control
lists, but there is no corresponding mount option. Add it and keep it
disabled by default.

Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@xxxxxxxxx>
---
 Documentation/filesystems/hfsplus.txt |  4 ++++
 fs/hfsplus/hfsplus_fs.h               |  1 +
 fs/hfsplus/options.c                  | 15 ++++++++++++++-
 fs/hfsplus/super.c                    |  1 +
 4 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/Documentation/filesystems/hfsplus.txt b/Documentation/filesystems/hfsplus.txt
index 59f7569..83670ac 100644
--- a/Documentation/filesystems/hfsplus.txt
+++ b/Documentation/filesystems/hfsplus.txt
@@ -43,6 +43,10 @@ When mounting an HFSPlus filesystem, the following options are accepted:
   nodecompose
 	Do not decompose file name characters.
 
+  acl
+	Enable POSIX Access Control Lists support, disabled by default.
+	Requires CONFIG_HFSPLUS_FS_POSIX_ACL set in the kernel configuration.
+
   force
 	Used to force write access to volumes that are marked as journalled
 	or locked.  Use at your own risk.
diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index a3f03b2..8bc78c1 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -153,6 +153,7 @@ struct hfsplus_sb_info {
 	struct inode *alloc_file;
 	struct inode *hidden_dir;
 	struct nls_table *nls;
+	struct super_block *sb;
 
 	/* Runtime variables */
 	u32 blockoffset;
diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index bb806e5..6f8b5a9 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c
@@ -24,7 +24,7 @@ enum {
 	opt_part, opt_session, opt_nls,
 	opt_nodecompose, opt_decompose,
 	opt_barrier, opt_nobarrier,
-	opt_force, opt_err
+	opt_force, opt_acl, opt_err
 };
 
 static const match_table_t tokens = {
@@ -41,6 +41,7 @@ static const match_table_t tokens = {
 	{ opt_barrier, "barrier" },
 	{ opt_nobarrier, "nobarrier" },
 	{ opt_force, "force" },
+	{ opt_acl, "acl" },
 	{ opt_err, NULL }
 };
 
@@ -195,6 +196,14 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
 		case opt_force:
 			set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
 			break;
+		case opt_acl:
+#ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
+			sbi->sb->s_flags |= MS_POSIXACL;
+			break;
+#else
+			pr_err("support for ACL not compiled in!");
+			return 0;
+#endif
 		default:
 			return 0;
 		}
@@ -234,5 +243,9 @@ int hfsplus_show_options(struct seq_file *seq, struct dentry *root)
 		seq_puts(seq, ",nodecompose");
 	if (test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
 		seq_puts(seq, ",nobarrier");
+#ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
+	if (sbi->sb->s_flags & MS_POSIXACL)
+		seq_puts(seq, ",acl");
+#endif
 	return 0;
 }
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 67aedf4..258fb86 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -389,6 +389,7 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
 		goto out;
 
 	sb->s_fs_info = sbi;
+	sbi->sb = sb;
 	mutex_init(&sbi->alloc_mutex);
 	mutex_init(&sbi->vh_mutex);
 	spin_lock_init(&sbi->work_lock);
-- 
2.1.4