[PATCH] knfsd: Avoid excess stack usage in svc_tcp_recvfrom
.. by allocating the array of 'kvec' in 'struct svc_rqst'.
As we plan to increase RPCSVC_MAXPAGES from 8 upto 256, we can no longer
allocate an array of this size on the stack. So we allocate it in 'struct
svc_rqst'.
However svc_rqst contains (indirectly) an array of the same type and size
(actually several, but they are in a union). So rather than waste space, we
move those arrays out of the separately allocated union and into svc_rqst to
share with the kvec moved out of svc_tcp_recvfrom (various arrays are used at
different times, so there is no conflict).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
index ad2fba3..ab6745e 100644
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c
@@ -263,9 +263,9 @@
v=0;
while (len > 0) {
pn = rqstp->rq_resused++;
- args->vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
- args->vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
- len -= args->vec[v].iov_len;
+ rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
+ rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
+ len -= rqstp->rq_vec[v].iov_len;
v++;
}
args->vlen = v;
@@ -285,21 +285,21 @@
args->offset = ntohl(*p++); /* offset */
p++; /* totalcount */
len = args->len = ntohl(*p++);
- args->vec[0].iov_base = (void*)p;
- args->vec[0].iov_len = rqstp->rq_arg.head[0].iov_len -
+ rqstp->rq_vec[0].iov_base = (void*)p;
+ rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len -
(((void*)p) - rqstp->rq_arg.head[0].iov_base);
if (len > NFSSVC_MAXBLKSIZE)
len = NFSSVC_MAXBLKSIZE;
v = 0;
- while (len > args->vec[v].iov_len) {
- len -= args->vec[v].iov_len;
+ while (len > rqstp->rq_vec[v].iov_len) {
+ len -= rqstp->rq_vec[v].iov_len;
v++;
- args->vec[v].iov_base = page_address(rqstp->rq_pages[v]);
- args->vec[v].iov_len = PAGE_SIZE;
+ rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
+ rqstp->rq_vec[v].iov_len = PAGE_SIZE;
}
- args->vec[v].iov_len = len;
+ rqstp->rq_vec[v].iov_len = len;
args->vlen = v+1;
- return args->vec[0].iov_len > 0;
+ return rqstp->rq_vec[0].iov_len > 0;
}
int