From a051f71ce97c53cde3ac64de64eb02d658d9308e Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Mon, 6 Feb 2012 15:14:40 -0500 Subject: [PATCH] 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 Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- Documentation/ioctl/ioctl-number.txt | 1 + fs/hfsplus/hfsplus_fs.h | 5 ++++ fs/hfsplus/ioctl.c | 34 ++++++++++++++++++++++++++++ 3 files changed, 40 insertions(+) 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 '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 @@ -316,6 +316,11 @@ static inline unsigned short hfsplus_min_io_size(struct super_block *sb) #define HFSPLUS_IOC_EXT2_SETFLAGS FS_IOC_SETFLAGS +/* + * 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 #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; } -- 2.20.1