Re: [PATCH v5 5/8] fat: restructure export_operations

From: Namjae Jeon
Date: Thu Dec 06 2012 - 04:43:25 EST


2012/12/6, OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>:
> Namjae Jeon <linkinjeon@xxxxxxxxx> writes:
>
>>> I know encode_fh(). But NFS is network protocol, and network can input
>>> any data, and I guess the userland interface (open_by_handle()?) can be
>>> any too.
>>>
>>> And generic_fh_to_dentry()'s input verify choose to check the minimum
>>> length only. But your logic choose the exact length.
>>>
>>> I think the both is sane and correct. But I wonder why did you changed
>>> it.
>> There was no particular reason for us to put those conditions. It is
>> just we knew what fh lengths we have chosen for the 2 cases
>> WITH/WITHOUT parent.
>> i.e., we checked with encoded length.
>> Now, when I check the export functions of other filesystems(btrfs,
>> nilfs2, udf). They also adopt the same method of checking the exact
>> length and type.
>> If there is any particular reason, we will look into that and can also
>> updated on that.
>
> OK. Then, just cleanup code, and let's use strict checking version.
>
> Removing strange fallthrou, something like the following.
>
> static struct dentry *fat_fh_to_dentry_nostale(struct super_block *sb,
> struct fid *fh, int fh_len,
> int fh_type)
> {
> struct inode *inode = NULL;
> struct fat_fid *fid = (struct fat_fid *)fh;
> loff_t i_pos;
>
> switch (fh_type) {
> case FILEID_FAT_WITHOUT_PARENT:
> if (fh_len < FAT_FID_SIZE_WITHOUT_PARENT)
> return NULL;
> break;
> case FILEID_FAT_WITH_PARENT:
> if (fh_len < FAT_FID_SIZE_WITH_PARENT)
> return NULL;
> break;
> default:
> return NULL;
> }
>
> i_pos = fid->i_pos_hi;
> i_pos = (i_pos << 32) | (fid->i_pos_low);
> inode = __fat_nfs_get_inode(sb, 0, fid->i_gen, i_pos);
>
> return d_obtain_alias(inode);
> }
Okay. I will change like this on next patch-set.

Thanks OGAWA!
>
>
> --
> OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
>
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