From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
There's no advantage to this zero-copy-style readlink encoding, and it
unnecessarily limits the kinds of compounds we can handle. (In practice
I can't see why a client would want e.g. multiple readlink calls in a
comound, but it's probably a spec violation for us not to handle it.)
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
---
fs/nfsd/nfs4xdr.c | 44 +++++++++++++-------------------------------
1 file changed, 13 insertions(+), 31 deletions(-)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 58717de..4dba311 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3154,8 +3154,9 @@ static __be32
nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
{
int maxcount;
+ __be32 wire_count;
+ int zero = 0;
struct xdr_stream *xdr = &resp->xdr;
- char *page;
int length_offset = xdr->buf->len;
__be32 *p;
@@ -3165,51 +3166,32 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd
p = xdr_reserve_space(xdr, 4);
if (!p)
return nfserr_resource;
-
- if (resp->xdr.buf->page_len)
- return nfserr_resource;
- if (!*resp->rqstp->rq_next_page)
- return nfserr_resource;
-
- page = page_address(*(resp->rqstp->rq_next_page++));
-
maxcount = PAGE_SIZE;
- if (xdr->end - xdr->p < 1)
+ p = xdr_reserve_space(xdr, maxcount);
+ if (!p)
return nfserr_resource;
-
/*
* XXX: By default, the ->readlink() VFS op will truncate symlinks
* if they would overflow the buffer. Is this kosher in NFSv4? If
* not, one easy fix is: if ->readlink() precisely fills the buffer,
* assume that truncation occurred, and return NFS4ERR_RESOURCE.
*/
- nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp, page, &maxcount);
+ nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp, (void *)p, &maxcount);
+
if (nfserr == nfserr_isdir)
- nfserr = nfserr_inval;
+ nfserr= nfserr_inval;
if (nfserr) {
xdr_truncate_encode(xdr, length_offset);
return nfserr;
}
- WRITE32(maxcount);
- resp->xdr.buf->head[0].iov_len = (char*)p
- - (char*)resp->xdr.buf->head[0].iov_base;
- resp->xdr.buf->page_len = maxcount;
- xdr->buf->len += maxcount;
- xdr->page_ptr += 1;
- xdr->buf->buflen -= PAGE_SIZE;
- xdr->iov = xdr->buf->tail;
-
- /* Use rest of head for padding and remaining ops: */
- resp->xdr.buf->tail[0].iov_base = p;
- resp->xdr.buf->tail[0].iov_len = 0;
- if (maxcount&3) {
- p = xdr_reserve_space(xdr, 4);
- WRITE32(0);
- resp->xdr.buf->tail[0].iov_base += maxcount&3;
- resp->xdr.buf->tail[0].iov_len = 4 - (maxcount&3);
- }
+ wire_count = htonl(maxcount);
+ write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
+ xdr_truncate_encode(xdr, length_offset + 4 + maxcount);
+ if (maxcount & 3)
+ write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
+ &zero, 4 - (maxcount&3));
return 0;
}
--
1.7.9.5
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