Commit 606b4aef authored by Neil Brown's avatar Neil Brown Committed by Linus Torvalds

[PATCH] NFSv3 to extract large symlinks from paginated requests.

Now that requests are broken into non-contiguous pages,
an NFSv3 symlink request could be larger than a page and
so non-continguous.
This patch copies the symlink into a new page (while checking
for nul bytes) so nfsd_symlink will definately get a
contiguous link.
parent 95ac0dbc
...@@ -438,13 +438,52 @@ int ...@@ -438,13 +438,52 @@ int
nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, u32 *p, nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, u32 *p,
struct nfsd3_symlinkargs *args) struct nfsd3_symlinkargs *args)
{ {
int len;
int avail;
char *old, *new;
struct iovec *vec;
if (!(p = decode_fh(p, &args->ffh)) if (!(p = decode_fh(p, &args->ffh))
|| !(p = decode_filename(p, &args->fname, &args->flen)) || !(p = decode_filename(p, &args->fname, &args->flen))
|| !(p = decode_sattr3(p, &args->attrs)) || !(p = decode_sattr3(p, &args->attrs))
|| !(p = decode_pathname(p, &args->tname, &args->tlen))) )
return 0;
/* now decode the pathname, which might be larger than the first page.
* As we have to check for nul's anyway, we copy it into a new page
* This page appears in the rq_res.pages list, but as pages_len is always
* 0, it won't get in the way
*/
svc_take_page(rqstp);
len = ntohl(*p++);
if (len <= 0 || len > NFS3_MAXPATHLEN)
return 0;
args->tname = new = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
args->tlen = len;
/* first copy and check from the first page */
old = (char*)p;
vec = &rqstp->rq_arg.head[0];
avail = vec->iov_len - (old - (char*)vec->iov_base);
while (len > 0 && *old && avail) {
*new++ = *old++;
len--;
avail--;
}
/* now copy next page if there is one */
if (len && !avail && rqstp->rq_arg.page_len) {
avail = rqstp->rq_arg.page_len;
if (avail > PAGE_SIZE) avail = PAGE_SIZE;
old = page_address(rqstp->rq_arg.pages[0]);
}
while (len > 0 && *old && avail) {
*new++ = *old++;
len--;
avail--;
}
*new = '\0';
if (len)
return 0; return 0;
return xdr_argsize_check(rqstp, p); return 1;
} }
int int
......
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