2012/12/3, OGAWA Hirofumi <hirof...@mail.parknet.co.jp>:
> Namjae Jeon <linkinj...@gmail.com> writes:
>
>> +    if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
>> +            /* Use i_pos for ino. This is used as fileid of nfs. */
>> +            stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
>
> BTW, what number is used for root dir? If it is 0 (0 is special ino in
> glibc), we have to use MSDOS_ROOT_INO instead.
we have used default root ino number which is MSDOS_ROOT_INO.
>
>> +#define FAT_FID_SIZE_WITHOUT_PARENT (offsetof(struct fat_fid, \
>> +                                          parent_i_pos_hi)/4)
>
> (offset parent_i_pos_hi) / 4 == 2. Wrong.
 Yes, this needs correction. Since, at all the places the condition
was for ‘fh_len < 2’ so this error condition was never caught.
>
>> +#define FAT_FID_SIZE_WITH_PARENT (sizeof(struct fat_fid)/4)
>
> 4 should be sizeof(u32). Or simplely use immediate value.
Okay.
>
>> +static int
>> +fat_encode_fh_nostale(struct inode *inode, __u32 *fh, int *lenp,
>> +                  struct inode *parent)
>> +{
>> +    int len = *lenp;
>> +    struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
>> +    struct fat_fid *fid = (struct fat_fid *) fh;
>> +    loff_t i_pos;
>> +    int type = FILEID_FAT_WITHOUT_PARENT;
>> +
>> +    if (parent && (len < FAT_FID_SIZE_WITH_PARENT)) {
>> +            *lenp = FAT_FID_SIZE_WITH_PARENT;
>> +            return 255;
>
> 255 is now FILEID_INVALID, I think.
Yes, right.
>
>> +    } else if (len < FAT_FID_SIZE_WITHOUT_PARENT) {
>> +            *lenp = FAT_FID_SIZE_WITHOUT_PARENT;
>> +            return 255;
>> +    }
>> +
>> +    i_pos = fat_i_pos_read(sbi, inode);
>> +    *lenp = FAT_FID_SIZE_WITHOUT_PARENT;
>> +    fid->i_gen = inode->i_generation;
>> +    fid->i_pos_low = i_pos & 0xFFFFFFFF;
>> +    fid->i_pos_hi = (i_pos >> 32) & 0xFFFF;
>> +    if (parent) {
>> +            i_pos = fat_i_pos_read(sbi, parent);
>> +            fid->parent_i_pos_hi = (i_pos >> 32) & 0xFFFF;
>> +            fid->parent_i_pos_low = i_pos & 0xFFFFFFFF;
>> +            fid->parent_i_gen = parent->i_generation;
>> +            type = FILEID_FAT_WITH_PARENT;
>> +            *lenp = FAT_FID_SIZE_WITH_PARENT;
>> +    }
>> +
>> +    return type;
>> +}
>> +
>>  /**
>>   * Map a NFS file handle to a corresponding dentry.
>>   * The dentry may or may not be connected to the filesystem root.
>>   */
>> -struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid,
>> +static struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid
>> *fid,
>>                              int fh_len, int fh_type)
>>  {
>>      return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
>>                                  fat_nfs_get_inode);
>>  }
>>
>> +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;
>> +    case FILEID_FAT_WITH_PARENT:
>> +            if ((fh_len < FAT_FID_SIZE_WITH_PARENT) &&
>> +                    (fh_type == FILEID_FAT_WITH_PARENT))
>> +                    return NULL;
>
> Do we have to care (FILEID_FAT_WITH_PARENT and fh_len < 5) here?
>
>       if (fh_len < 2)
>               return NULL;
>
>       switch (fh_type) {
>       case FILEID_INO32_GEN:
>       case FILEID_INO32_GEN_PARENT:
>               inode = get_inode(sb, fid->i32.ino, fid->i32.gen);
>               break;
>       }
>
>       return d_obtain_alias(inode);
>
> generic_fh_to_dentry() is above. I wonder why we have to care
> fat_fid->parent* here.
Let me think, if ‘subtree’ checking is enabled then we should check
the length condition over here also? Please share if there are any
other comments also.

Thanks.
> --
> OGAWA Hirofumi <hirof...@mail.parknet.co.jp>
>
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