2 files changed, 39 insertions, 0 deletions

diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index 21a5b7fc6db4..4e75ac646fea 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -317,6 +317,11 @@ static inline unsigned short hfsplus_min_io_size(struct super_block *sb)
 
 
 /*
+ * hfs+-specific ioctl for making the filesystem bootable
+ */
+#define HFSPLUS_IOC_BLESS _IO('h', 0x80)
+
+/*
  * Functions in any *.c used in other files
  */
 
diff --git a/fs/hfsplus/ioctl.c b/fs/hfsplus/ioctl.c
index f66c7655b3f7..c640ba57074b 100644
--- a/fs/hfsplus/ioctl.c
+++ b/fs/hfsplus/ioctl.c
@@ -20,6 +20,38 @@
 #include <asm/uaccess.h>
 #include "hfsplus_fs.h"
 
+/*
+ * "Blessing" an HFS+ filesystem writes metadata to the superblock informing
+ * the platform firmware which file to boot from
+ */
+static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
+{
+        struct dentry *dentry = file->f_path.dentry;
+        struct inode *inode = dentry->d_inode;
+        struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
+        struct hfsplus_vh *vh = sbi->s_vhdr;
+        struct hfsplus_vh *bvh = sbi->s_backup_vhdr;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        mutex_lock(&sbi->vh_mutex);
+
+        /* Directory containing the bootable system */
+        vh->finder_info[0] = bvh->finder_info[0] =
+                cpu_to_be32(parent_ino(dentry));
+
+        /* Bootloader */
+        vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(inode->i_ino);
+
+        /* Per spec, the OS X system folder - same as finder_info[0] here */
+        vh->finder_info[5] = bvh->finder_info[5] =
+                cpu_to_be32(parent_ino(dentry));
+
+        mutex_unlock(&sbi->vh_mutex);
+        return 0;
+}
+
 static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
 {
         struct inode *inode = file->f_path.dentry->d_inode;
@@ -108,6 +140,8 @@ long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                 return hfsplus_ioctl_getflags(file, argp);
         case HFSPLUS_IOC_EXT2_SETFLAGS:
                 return hfsplus_ioctl_setflags(file, argp);
+        case HFSPLUS_IOC_BLESS:
+                return hfsplus_ioctl_bless(file, argp);
         default:
                 return -ENOTTY;
         }