On Mon, Feb 28, 2011 at 5:42 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
> On Mon, Feb 28, 2011 at 04:58:57PM -0600, Steve French wrote:
>> On Mon, Feb 28, 2011 at 4:49 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
>> > On Mon, Feb 28, 2011 at 03:52:41PM -0600, shirishpargaonkar@xxxxxxxxx wrote:
>> >> +static struct dentry *
>> >> +cifs_fh_to_dentry(struct super_block *sb, struct fid *fh,
>> >> + int fh_len, int fh_type)
>> >> +{
>> >> + struct cifs_fid *cfid = (struct cifs_fid *)fh;
>> >> + struct inode *inode = NULL;
>> >> + struct cifs_fattr fattr;
>> >> +
>> >>
>> >> -#endif /* CIFS_NFSD_EXPORT */
>> >> + if (fh_type != FILEID_INO32_GEN && fh_type != FILEID_INO32_GEN_PARENT) {
>> >> + cERROR(1, "%s: Can't handle fh type: %d", __func__, fh_type);
>> >> + return ERR_PTR(-EINVAL);
>> >> + }
>> >>
>> >> + if (!cfid->cino)
>> >> + return ERR_PTR(-ESTALE);
>> >> +
>> >> + fattr.cf_uniqueid = cfid->cino;
>> >> + inode = iget5_locked(sb, cfid->cino, cifs_find_inode_id,
>> >> + cifs_init_inode, &fattr);
>> >> + if (IS_ERR(inode))
>> >> + return ERR_CAST(inode);
>> >> +
>> >> + return d_obtain_alias(inode);
>> >
>> > Does the cifs protocol give the client a way to look up a file by inode
>> > number (or filehandle or equivalent?).
>>
>> There is a unique identifier similar to inode number returned by
>> various info calls,
>> but cifs calls use either a file handle (returned by an open) or path name to
>> look up metadata on a file.
>>
>> Not sure whether the unique identifier can be passed in as input to an
>> ioctl useful here.
>
> OK. Then as things stand we're stuck returning ESTALE to the client
> unless we happen to have the inode they're looking for in our cache?
Yes - that seems right and consistent with what I remember other file
systems doing.
IIRC LInux nfs clients handle this already.
--
Thanks,
Steve
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