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[PATCH] knfsd: Avoid excess stack usage in svc_tcp_recvfrom

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..  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>
This commit is contained in:
NeilBrown
2006-10-04 02:15:47 -07:00
committed by Linus Torvalds
parent 4452435948
commit 3cc03b164c
11 changed files with 44 additions and 47 deletions
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22
fs/nfsd/nfsxdr.c
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@@ -263,9 +263,9 @@ nfssvc_decode_readargs(struct svc_rqst *rqstp, u32 *p,
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 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, u32 *p,
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