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authorNeilBrown <neilb@suse.de>2006-04-10 22:55:32 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-04-11 06:18:52 -0700
commit6ed6decccf544970664757464cfb67e081775e6a (patch)
tree9aa6b62856426e5aba7f34b3bbc9b24c87a54b87
parentf0e2993e9e73e8f38b05a89c98b9db94fec2199d (diff)
downloadlinux-6ed6decccf544970664757464cfb67e081775e6a.tar.bz2
[PATCH] knfsd: nfsd4: fix corruption of returned data when using 64k pages
In v4 we grab an extra page just for the padding of returned data. The formula that the rpc server uses to allocate pages for the response doesn't take into account this extra page. Instead of adjusting those formulae, we adopt the same solution as v2 and v3, and put the "tail" data in the same page as the "head" data. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/nfsd/nfs4xdr.c42
1 files changed, 17 insertions, 25 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 845f25251d81..f2710cfc0bc5 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2084,27 +2084,20 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_read
WRITE32(eof);
WRITE32(maxcount);
ADJUST_ARGS();
- resp->xbuf->head[0].iov_len = ((char*)resp->p) - (char*)resp->xbuf->head[0].iov_base;
-
+ resp->xbuf->head[0].iov_len = (char*)p
+ - (char*)resp->xbuf->head[0].iov_base;
resp->xbuf->page_len = maxcount;
- /* read zero bytes -> don't set up tail */
- if(!maxcount)
- return 0;
-
- /* set up page for remaining responses */
- svc_take_page(resp->rqstp);
- resp->xbuf->tail[0].iov_base =
- page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused-1]);
- resp->rqstp->rq_restailpage = resp->rqstp->rq_resused-1;
+ /* Use rest of head for padding and remaining ops: */
+ resp->rqstp->rq_restailpage = 0;
+ resp->xbuf->tail[0].iov_base = p;
resp->xbuf->tail[0].iov_len = 0;
- resp->p = resp->xbuf->tail[0].iov_base;
- resp->end = resp->p + PAGE_SIZE/4;
-
if (maxcount&3) {
- *(resp->p)++ = 0;
+ RESERVE_SPACE(4);
+ WRITE32(0);
resp->xbuf->tail[0].iov_base += maxcount&3;
resp->xbuf->tail[0].iov_len = 4 - (maxcount&3);
+ ADJUST_ARGS();
}
return 0;
}
@@ -2141,21 +2134,20 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_r
WRITE32(maxcount);
ADJUST_ARGS();
- resp->xbuf->head[0].iov_len = ((char*)resp->p) - (char*)resp->xbuf->head[0].iov_base;
+ resp->xbuf->head[0].iov_len = (char*)p
+ - (char*)resp->xbuf->head[0].iov_base;
+ resp->xbuf->page_len = maxcount;
- svc_take_page(resp->rqstp);
- resp->xbuf->tail[0].iov_base =
- page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused-1]);
- resp->rqstp->rq_restailpage = resp->rqstp->rq_resused-1;
+ /* Use rest of head for padding and remaining ops: */
+ resp->rqstp->rq_restailpage = 0;
+ resp->xbuf->tail[0].iov_base = p;
resp->xbuf->tail[0].iov_len = 0;
- resp->p = resp->xbuf->tail[0].iov_base;
- resp->end = resp->p + PAGE_SIZE/4;
-
- resp->xbuf->page_len = maxcount;
if (maxcount&3) {
- *(resp->p)++ = 0;
+ RESERVE_SPACE(4);
+ WRITE32(0);
resp->xbuf->tail[0].iov_base += maxcount&3;
resp->xbuf->tail[0].iov_len = 4 - (maxcount&3);
+ ADJUST_ARGS();
}
return 0;
}