aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMatthew Garrett <mjg@redhat.com>2012-02-06 15:14:40 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2012-03-20 21:29:53 -0400
commita051f71ce97c53cde3ac64de64eb02d658d9308e (patch)
treeef36c0a2e8c9e9dfb97ee12ba35fccca32858909
parent0347b6e95ceeb648631f89a0ced001e90e4daaa9 (diff)
hfsplus: add an ioctl to bless files
Making an hfsplus partition bootable requires the ability to "bless" a file by putting its inode number in the volume header. Doing this from userspace on a mounted filesystem is impractical since the kernel will write back the original values on unmount. Add an ioctl to allow userspace to update the volume header information based on the target file. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--Documentation/ioctl/ioctl-number.txt1
-rw-r--r--fs/hfsplus/hfsplus_fs.h5
-rw-r--r--fs/hfsplus/ioctl.c34
3 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 4840334ea97b..37a424868eea 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -218,6 +218,7 @@ Code Seq#(hex) Include File Comments
'h' 00-7F conflict! Charon filesystem
<mailto:zapman@interlan.net>
'h' 00-1F linux/hpet.h conflict!
+'h' 80-8F fs/hfsplus/ioctl.c
'i' 00-3F linux/i2o-dev.h conflict!
'i' 0B-1F linux/ipmi.h conflict!
'i' 80-8F linux/i8k.h
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;
}

Privacy Policy