nfs3xdr.c

linux 内核源代码

	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->cookie);
	args->verf   = p; p += 2;
	args->dircount = ~0;
	args->count  = ntohl(*p++);

	if (args->count > PAGE_SIZE)
		args->count = PAGE_SIZE;

	args->buffer =
		page_address(rqstp->rq_respages[rqstp->rq_resused++]);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readdirargs *args)
{
	int len, pn;
	u32 max_blocksize = svc_max_payload(rqstp);

	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->cookie);
	args->verf     = p; p += 2;
	args->dircount = ntohl(*p++);
	args->count    = ntohl(*p++);

	len = (args->count > max_blocksize) ? max_blocksize :
						  args->count;
	args->count = len;

	while (len > 0) {
		pn = rqstp->rq_resused++;
		if (!args->buffer)
			args->buffer = page_address(rqstp->rq_respages[pn]);
		len -= PAGE_SIZE;
	}

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_commitargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->offset);
	args->count = ntohl(*p++);

	return xdr_argsize_check(rqstp, p);
}

/*
 * XDR encode functions
 */
/*
 * There must be an encoding function for void results so svc_process
 * will work properly.
 */
int
nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
	return xdr_ressize_check(rqstp, p);
}

/* GETATTR */
int
nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_attrstat *resp)
{
	if (resp->status == 0) {
		lease_get_mtime(resp->fh.fh_dentry->d_inode,
				&resp->stat.mtime);
		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
	}
	return xdr_ressize_check(rqstp, p);
}

/* SETATTR, REMOVE, RMDIR */
int
nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_attrstat *resp)
{
	p = encode_wcc_data(rqstp, p, &resp->fh);
	return xdr_ressize_check(rqstp, p);
}

/* LOOKUP */
int
nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_diropres *resp)
{
	if (resp->status == 0) {
		p = encode_fh(p, &resp->fh);
		p = encode_post_op_attr(rqstp, p, &resp->fh);
	}
	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
	return xdr_ressize_check(rqstp, p);
}

/* ACCESS */
int
nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_accessres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);
	if (resp->status == 0)
		*p++ = htonl(resp->access);
	return xdr_ressize_check(rqstp, p);
}

/* READLINK */
int
nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readlinkres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);
	if (resp->status == 0) {
		*p++ = htonl(resp->len);
		xdr_ressize_check(rqstp, p);
		rqstp->rq_res.page_len = resp->len;
		if (resp->len & 3) {
			/* need to pad the tail */
			rqstp->rq_res.tail[0].iov_base = p;
			*p = 0;
			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
		}
		return 1;
	} else
		return xdr_ressize_check(rqstp, p);
}

/* READ */
int
nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);
	if (resp->status == 0) {
		*p++ = htonl(resp->count);
		*p++ = htonl(resp->eof);
		*p++ = htonl(resp->count);	/* xdr opaque count */
		xdr_ressize_check(rqstp, p);
		/* now update rqstp->rq_res to reflect data aswell */
		rqstp->rq_res.page_len = resp->count;
		if (resp->count & 3) {
			/* need to pad the tail */
			rqstp->rq_res.tail[0].iov_base = p;
			*p = 0;
			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
		}
		return 1;
	} else
		return xdr_ressize_check(rqstp, p);
}

/* WRITE */
int
nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_writeres *resp)
{
	p = encode_wcc_data(rqstp, p, &resp->fh);
	if (resp->status == 0) {
		*p++ = htonl(resp->count);
		*p++ = htonl(resp->committed);
		*p++ = htonl(nfssvc_boot.tv_sec);
		*p++ = htonl(nfssvc_boot.tv_usec);
	}
	return xdr_ressize_check(rqstp, p);
}

/* CREATE, MKDIR, SYMLINK, MKNOD */
int
nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_diropres *resp)
{
	if (resp->status == 0) {
		*p++ = xdr_one;
		p = encode_fh(p, &resp->fh);
		p = encode_post_op_attr(rqstp, p, &resp->fh);
	}
	p = encode_wcc_data(rqstp, p, &resp->dirfh);
	return xdr_ressize_check(rqstp, p);
}

/* RENAME */
int
nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_renameres *resp)
{
	p = encode_wcc_data(rqstp, p, &resp->ffh);
	p = encode_wcc_data(rqstp, p, &resp->tfh);
	return xdr_ressize_check(rqstp, p);
}

/* LINK */
int
nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_linkres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);
	p = encode_wcc_data(rqstp, p, &resp->tfh);
	return xdr_ressize_check(rqstp, p);
}

/* READDIR */
int
nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readdirres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);

	if (resp->status == 0) {
		/* stupid readdir cookie */
		memcpy(p, resp->verf, 8); p += 2;
		xdr_ressize_check(rqstp, p);
		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
			return 1; /*No room for trailer */
		rqstp->rq_res.page_len = (resp->count) << 2;

		/* add the 'tail' to the end of the 'head' page - page 0. */
		rqstp->rq_res.tail[0].iov_base = p;
		*p++ = 0;		/* no more entries */
		*p++ = htonl(resp->common.err == nfserr_eof);
		rqstp->rq_res.tail[0].iov_len = 2<<2;
		return 1;
	} else
		return xdr_ressize_check(rqstp, p);
}

static __be32 *
encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
	     int namlen, u64 ino)
{
	*p++ = xdr_one;				 /* mark entry present */
	p    = xdr_encode_hyper(p, ino);	 /* file id */
	p    = xdr_encode_array(p, name, namlen);/* name length & name */

	cd->offset = p;				/* remember pointer */
	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */

	return p;
}

static __be32 *
encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p,
		struct svc_fh *fhp)
{
		p = encode_post_op_attr(cd->rqstp, p, fhp);
		*p++ = xdr_one;			/* yes, a file handle follows */
		p = encode_fh(p, fhp);
		fh_put(fhp);
		return p;
}

static int
compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
		const char *name, int namlen)
{
	struct svc_export	*exp;
	struct dentry		*dparent, *dchild;
	int rv = 0;

	dparent = cd->fh.fh_dentry;
	exp  = cd->fh.fh_export;

	fh_init(fhp, NFS3_FHSIZE);
	if (isdotent(name, namlen)) {
		if (namlen == 2) {
			dchild = dget_parent(dparent);
			if (dchild == dparent) {
				/* filesystem root - cannot return filehandle for ".." */
				dput(dchild);
				return 1;
			}
		} else
			dchild = dget(dparent);
	} else
		dchild = lookup_one_len(name, dparent, namlen);
	if (IS_ERR(dchild))
		return 1;
	if (d_mountpoint(dchild) ||
	    fh_compose(fhp, exp, dchild, &cd->fh) != 0 ||
	    !dchild->d_inode)
		rv = 1;
	dput(dchild);
	return rv;
}

/*
 * Encode a directory entry. This one works for both normal readdir
 * and readdirplus.
 * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
 * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
 * 
 * The readdirplus baggage is 1+21 words for post_op_attr, plus the
 * file handle.
 */

#define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
#define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
static int
encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
	     loff_t offset, u64 ino, unsigned int d_type, int plus)
{
	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
		       					common);
	__be32		*p = cd->buffer;
	caddr_t		curr_page_addr = NULL;
	int		pn;		/* current page number */
	int		slen;		/* string (name) length */
	int		elen;		/* estimated entry length in words */
	int		num_entry_words = 0;	/* actual number of words */

	if (cd->offset) {
		u64 offset64 = offset;

		if (unlikely(cd->offset1)) {
			/* we ended up with offset on a page boundary */
			*cd->offset = htonl(offset64 >> 32);
			*cd->offset1 = htonl(offset64 & 0xffffffff);
			cd->offset1 = NULL;
		} else {
			xdr_encode_hyper(cd->offset, offset64);
		}
	}

	/*
	dprintk("encode_entry(%.*s @%ld%s)\n",
		namlen, name, (long) offset, plus? " plus" : "");
	 */

	/* truncate filename if too long */
	if (namlen > NFS3_MAXNAMLEN)
		namlen = NFS3_MAXNAMLEN;

	slen = XDR_QUADLEN(namlen);
	elen = slen + NFS3_ENTRY_BAGGAGE
		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);

	if (cd->buflen < elen) {
		cd->common.err = nfserr_toosmall;
		return -EINVAL;
	}

	/* determine which page in rq_respages[] we are currently filling */
	for (pn=1; pn < cd->rqstp->rq_resused; pn++) {
		curr_page_addr = page_address(cd->rqstp->rq_respages[pn]);

		if (((caddr_t)cd->buffer >= curr_page_addr) &&
		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
			break;
	}

	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
		/* encode entry in current page */

		p = encode_entry_baggage(cd, p, name, namlen, ino);

		/* throw in readdirplus baggage */
		if (plus) {
			struct svc_fh	fh;

			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
				*p++ = 0;
				*p++ = 0;
			} else
				p = encode_entryplus_baggage(cd, p, &fh);
		}
		num_entry_words = p - cd->buffer;
	} else if (cd->rqstp->rq_respages[pn+1] != NULL) {
		/* temporarily encode entry into next page, then move back to
		 * current and next page in rq_respages[] */
		__be32 *p1, *tmp;
		int len1, len2;

		/* grab next page for temporary storage of entry */
		p1 = tmp = page_address(cd->rqstp->rq_respages[pn+1]);

		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);

		/* throw in readdirplus baggage */
		if (plus) {
			struct svc_fh	fh;

			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
				/* zero out the filehandle */
				*p1++ = 0;
				*p1++ = 0;
			} else
				p1 = encode_entryplus_baggage(cd, p1, &fh);
		}

		/* determine entry word length and lengths to go in pages */
		num_entry_words = p1 - tmp;
		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
		if ((num_entry_words << 2) < len1) {
			/* the actual number of words in the entry is less
			 * than elen and can still fit in the current page
			 */
			memmove(p, tmp, num_entry_words << 2);
			p += num_entry_words;

			/* update offset */
			cd->offset = cd->buffer + (cd->offset - tmp);
		} else {
			unsigned int offset_r = (cd->offset - tmp) << 2;

			/* update pointer to offset location.
			 * This is a 64bit quantity, so we need to
			 * deal with 3 cases:
			 *  -	entirely in first page
			 *  -	entirely in second page
			 *  -	4 bytes in each page
			 */
			if (offset_r + 8 <= len1) {
				cd->offset = p + (cd->offset - tmp);
			} else if (offset_r >= len1) {
				cd->offset -= len1 >> 2;
			} else {
				/* sitting on the fence */
				BUG_ON(offset_r != len1 - 4);
				cd->offset = p + (cd->offset - tmp);
				cd->offset1 = tmp;
			}

			len2 = (num_entry_words << 2) - len1;

			/* move from temp page to current and next pages */
			memmove(p, tmp, len1);
			memmove(tmp, (caddr_t)tmp+len1, len2);

			p = tmp + (len2 >> 2);
		}
	}
	else {
		cd->common.err = nfserr_toosmall;
		return -EINVAL;
	}

	cd->buflen -= num_entry_words;
	cd->buffer = p;
	cd->common.err = nfs_ok;
	return 0;

}

int
nfs3svc_encode_entry(void *cd, const char *name,
		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
{
	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
}

int
nfs3svc_encode_entry_plus(void *cd, const char *name,
			  int namlen, loff_t offset, u64 ino,
			  unsigned int d_type)
{
	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
}

/* FSSTAT */
int
nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_fsstatres *resp)
{
	struct kstatfs	*s = &resp->stats;
	u64		bs = s->f_bsize;

	*p++ = xdr_zero;	/* no post_op_attr */

	if (resp->status == 0) {
		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
	}
	return xdr_ressize_check(rqstp, p);
}

/* FSINFO */
int
nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_fsinfores *resp)
{
	*p++ = xdr_zero;	/* no post_op_attr */

	if (resp->status == 0) {
		*p++ = htonl(resp->f_rtmax);
		*p++ = htonl(resp->f_rtpref);
		*p++ = htonl(resp->f_rtmult);
		*p++ = htonl(resp->f_wtmax);
		*p++ = htonl(resp->f_wtpref);
		*p++ = htonl(resp->f_wtmult);
		*p++ = htonl(resp->f_dtpref);
		p = xdr_encode_hyper(p, resp->f_maxfilesize);
		*p++ = xdr_one;
		*p++ = xdr_zero;
		*p++ = htonl(resp->f_properties);
	}

	return xdr_ressize_check(rqstp, p);
}

/* PATHCONF */
int
nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_pathconfres *resp)
{
	*p++ = xdr_zero;	/* no post_op_attr */

	if (resp->status == 0) {
		*p++ = htonl(resp->p_link_max);
		*p++ = htonl(resp->p_name_max);
		*p++ = htonl(resp->p_no_trunc);
		*p++ = htonl(resp->p_chown_restricted);
		*p++ = htonl(resp->p_case_insensitive);
		*p++ = htonl(resp->p_case_preserving);
	}

	return xdr_ressize_check(rqstp, p);
}

/* COMMIT */
int
nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_commitres *resp)
{
	p = encode_wcc_data(rqstp, p, &resp->fh);
	/* Write verifier */
	if (resp->status == 0) {
		*p++ = htonl(nfssvc_boot.tv_sec);
		*p++ = htonl(nfssvc_boot.tv_usec);
	}
	return xdr_ressize_check(rqstp, p);
}

/*
 * XDR release functions
 */
int
nfs3svc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_attrstat *resp)
{
	fh_put(&resp->fh);
	return 1;
}

int
nfs3svc_release_fhandle2(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_fhandle_pair *resp)
{
	fh_put(&resp->fh1);
	fh_put(&resp->fh2);
	return 1;
}