On 2010-05-20, at 17:34, Ben Hutchings wrote:
> struct ext4_new_group_input needs to be converted because u64 has
> only 32-bit alignment on some 32-bit architectures, notably i386.
Sigh, it would have been nice to catch this when ext4_new_group_input was first created.
I don't mind fixing the kernel, since this is clearly broken. However, we may as well go ahead and declare a new struct ext4_new_group_input that has the right alignment, rename and deprecate the old one (have resize2fs prefer the new one if available) and take the old one out in a few years. I hate this business of keeping around old cruft like this forever.
struct compat_ext4_new_group_input {
u32 group;
u64 block_bitmap;
u64 inode_bitmap;
u64 inode_table;
u32 blocks_count;
u16 reserved_blocks;
u16 unused;
};
struct ext4_new_group_input {
u64 group;
u64 block_bitmap;
u64 inode_bitmap;
u64 inode_table;
u64 blocks_count;
u32 reserved_blocks;
u32 unused;
};
#define EXT2_IOC_GROUP_ADD _IOW('f', 8,struct ext2_new_group_input)
#define EXT4_IOC_GROUP_ADD_OLD _IOW('f', 8,struct compat_ext4_new_group_input)
#define EXT4_IOC_GROUP_ADD _IOW('f', 8,struct ext4_new_group_input)
The resize/online.c code already has compat support for both 32-bit and 64-bit IOC numbers, so it isn't much effort to have it try a third variant for a couple of years.
> +#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
> +struct compat_ext4_new_group_input {
> + u32 group;
> + compat_u64 block_bitmap;
> + compat_u64 inode_bitmap;
> + compat_u64 inode_table;
> + u32 blocks_count;
> + u16 reserved_blocks;
> + u16 unused;
> +};
> +#endif
> +
> /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
> struct ext4_new_group_data {
> __u32 group;
> @@ -409,6 +424,7 @@ struct ext4_new_group_data {
> #define EXT4_IOC32_GETRSVSZ _IOR('f', 5, int)
> #define EXT4_IOC32_SETRSVSZ _IOW('f', 6, int)
> #define EXT4_IOC32_GROUP_EXTEND _IOW('f', 7, unsigned int)
> +#define EXT4_IOC32_GROUP_ADD _IOW('f', 8, struct compat_ext4_new_group_input)
> #ifdef CONFIG_JBD2_DEBUG
> #define EXT4_IOC32_WAIT_FOR_READONLY _IOR('f', 99, int)
> #endif
> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
> index 66fa0b0..6ddec84 100644
> --- a/fs/ext4/ioctl.c
> +++ b/fs/ext4/ioctl.c
> @@ -373,8 +373,29 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> case EXT4_IOC32_SETRSVSZ:
> cmd = EXT4_IOC_SETRSVSZ;
> break;
> - case EXT4_IOC_GROUP_ADD:
> - break;
> + case EXT4_IOC32_GROUP_ADD: {
> + struct compat_ext4_new_group_input __user *uinput;
> + struct ext4_new_group_input input;
> + mm_segment_t old_fs;
> + int err;
> +
> + uinput = compat_ptr(arg);
> + err = get_user(input.group, &uinput->group);
> + err |= get_user(input.block_bitmap, &uinput->block_bitmap);
> + err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
> + err |= get_user(input.inode_table, &uinput->inode_table);
> + err |= get_user(input.blocks_count, &uinput->blocks_count);
> + err |= get_user(input.reserved_blocks,
> + &uinput->reserved_blocks);
> + if (err)
> + return -EFAULT;
> + old_fs = get_fs();
> + set_fs(KERNEL_DS);
> + err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
> + (unsigned long) &input);
> + set_fs(old_fs);
> + return err;
> + }
> case EXT4_IOC_MOVE_EXT:
> break;
> default:
> --
> 1.7.1
>
>
Cheers, Andreas
--
Andreas Dilger
Lustre Technical Lead
Oracle Corporation Canada Inc.
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
