Commit f5dcccd6 authored by Chuck Lever's avatar Chuck Lever
Browse files

NFSD: Update the NFSv2 READDIR entry encoder to use struct xdr_stream 



Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 94c8f8c6

fs/nfsd/nfsproc.c

+19 −7
Original line number Diff line number Diff line
@@ -559,14 +559,27 @@ static void nfsd_init_dirlist_pages(struct svc_rqst *rqstp, 
				    struct nfsd_readdirres *resp,

				    int count)

{

	struct xdr_buf *buf = &resp->dirlist;

	struct xdr_stream *xdr = &resp->xdr;



	count = min_t(u32, count, PAGE_SIZE);



	/* Convert byte count to number of words (i.e. >> 2),

	 * and reserve room for the NULL ptr & eof flag (-2 words) */

	resp->buflen = (count >> 2) - 2;

	memset(buf, 0, sizeof(*buf));



	resp->buffer = page_address(*rqstp->rq_next_page);

	/* Reserve room for the NULL ptr & eof flag (-2 words) */

	buf->buflen = count - sizeof(__be32) * 2;

	buf->pages = rqstp->rq_next_page;

	rqstp->rq_next_page++;



	/* This is xdr_init_encode(), but it assumes that

	 * the head kvec has already been consumed. */

	xdr_set_scratch_buffer(xdr, NULL, 0);

	xdr->buf = buf;

	xdr->page_ptr = buf->pages;

	xdr->iov = NULL;

	xdr->p = page_address(*buf->pages);

	xdr->end = xdr->p + (PAGE_SIZE >> 2);

	xdr->rqst = NULL;

}



/*
@@ -585,12 +598,11 @@ nfsd_proc_readdir(struct svc_rqst *rqstp) 


	nfsd_init_dirlist_pages(rqstp, resp, argp->count);



	resp->offset = NULL;

	resp->common.err = nfs_ok;

	/* Read directory and encode entries on the fly */

	resp->cookie_offset = 0;

	offset = argp->cookie;

	resp->status = nfsd_readdir(rqstp, &argp->fh, &offset,

				    &resp->common, nfssvc_encode_entry);

				    &resp->common, nfs2svc_encode_entry);

	nfssvc_encode_nfscookie(resp, offset);



	fh_put(&argp->fh);

fs/nfsd/nfsxdr.c

+77 −4
Original line number Diff line number Diff line
@@ -576,12 +576,13 @@ nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p) 
{

	struct xdr_stream *xdr = &rqstp->rq_res_stream;

	struct nfsd_readdirres *resp = rqstp->rq_resp;

	struct xdr_buf *dirlist = &resp->dirlist;



	if (!svcxdr_encode_stat(xdr, resp->status))

		return 0;

	switch (resp->status) {

	case nfs_ok:

		xdr_write_pages(xdr, &resp->page, 0, resp->count << 2);

		xdr_write_pages(xdr, dirlist->pages, 0, dirlist->len);

		/* no more entries */

		if (xdr_stream_encode_item_absent(xdr) < 0)

			return 0;
@@ -623,14 +624,86 @@ nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p) 
 * @resp: readdir result context

 * @offset: offset cookie to encode

 *

 * The buffer space for the offset cookie has already been reserved

 * by svcxdr_encode_entry_common().

 */

void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset)

{

	if (!resp->offset)

	__be32 cookie = cpu_to_be32(offset);



	if (!resp->cookie_offset)

		return;



	*resp->offset = cpu_to_be32(offset);

	resp->offset = NULL;

	write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,

			       sizeof(cookie));

	resp->cookie_offset = 0;

}



static bool

svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name,

			   int namlen, loff_t offset, u64 ino)

{

	struct xdr_buf *dirlist = &resp->dirlist;

	struct xdr_stream *xdr = &resp->xdr;



	if (xdr_stream_encode_item_present(xdr) < 0)

		return false;

	/* fileid */

	if (xdr_stream_encode_u32(xdr, (u32)ino) < 0)

		return false;

	/* name */

	if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0)

		return false;

	/* cookie */

	resp->cookie_offset = dirlist->len;

	if (xdr_stream_encode_u32(xdr, ~0U) < 0)

		return false;



	return true;

}



/**

 * nfs2svc_encode_entry - encode one NFSv2 READDIR entry

 * @data: directory context

 * @name: name of the object to be encoded

 * @namlen: length of that name, in bytes

 * @offset: the offset of the previous entry

 * @ino: the fileid of this entry

 * @d_type: unused

 *

 * Return values:

 *   %0: Entry was successfully encoded.

 *   %-EINVAL: An encoding problem occured, secondary status code in resp->common.err

 *

 * On exit, the following fields are updated:

 *   - resp->xdr

 *   - resp->common.err

 *   - resp->cookie_offset

 */

int nfs2svc_encode_entry(void *data, const char *name, int namlen,

			 loff_t offset, u64 ino, unsigned int d_type)

{

	struct readdir_cd *ccd = data;

	struct nfsd_readdirres *resp = container_of(ccd,

						    struct nfsd_readdirres,

						    common);

	unsigned int starting_length = resp->dirlist.len;



	/* The offset cookie for the previous entry */

	nfssvc_encode_nfscookie(resp, offset);



	if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino))

		goto out_toosmall;



	xdr_commit_encode(&resp->xdr);

	resp->common.err = nfs_ok;

	return 0;



out_toosmall:

	resp->cookie_offset = 0;

	resp->common.err = nfserr_toosmall;

	resp->dirlist.len = starting_length;

	return -EINVAL;

}



int

fs/nfsd/xdr.h

+7 −0
Original line number Diff line number Diff line
@@ -106,15 +106,20 @@ struct nfsd_readres { 
};



struct nfsd_readdirres {

	/* Components of the reply */

	__be32			status;



	int			count;



	/* Used to encode the reply's entry list */

	struct xdr_stream	xdr;

	struct xdr_buf		dirlist;

	struct readdir_cd	common;

	__be32 *		buffer;

	int			buflen;

	__be32 *		offset;

	struct page		*page;

	unsigned int		cookie_offset;

};



struct nfsd_statfsres {
@@ -159,6 +164,8 @@ int nfssvc_encode_statfsres(struct svc_rqst *, __be32 *); 
int nfssvc_encode_readdirres(struct svc_rqst *, __be32 *);



void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset);

int nfs2svc_encode_entry(void *data, const char *name, int namlen,

			 loff_t offset, u64 ino, unsigned int d_type);

int nfssvc_encode_entry(void *, const char *name,

			int namlen, loff_t offset, u64 ino, unsigned int);