Commit 3cc03b16 authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[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: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 44524359
......@@ -180,7 +180,7 @@ nfsd3_proc_read(struct svc_rqst *rqstp, struct nfsd3_readargs *argp,
fh_copy(&resp->fh, &argp->fh);
nfserr = nfsd_read(rqstp, &resp->fh, NULL,
argp->offset,
argp->vec, argp->vlen,
rqstp->rq_vec, argp->vlen,
&resp->count);
if (nfserr == 0) {
struct inode *inode = resp->fh.fh_dentry->d_inode;
......@@ -210,7 +210,7 @@ nfsd3_proc_write(struct svc_rqst *rqstp, struct nfsd3_writeargs *argp,
resp->committed = argp->stable;
nfserr = nfsd_write(rqstp, &resp->fh, NULL,
argp->offset,
argp->vec, argp->vlen,
rqstp->rq_vec, argp->vlen,
argp->len,
&resp->committed);
resp->count = argp->count;
......
......@@ -344,9 +344,9 @@ nfs3svc_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;
......@@ -372,22 +372,22 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, u32 *p,
rqstp->rq_arg.len - hdr < len)
return 0;
args->vec[0].iov_base = (void*)p;
args->vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
rqstp->rq_vec[0].iov_base = (void*)p;
rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
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->count == args->len && args->vec[0].iov_len > 0;
return args->count == args->len && rqstp->rq_vec[0].iov_len > 0;
}
int
......
......@@ -646,7 +646,7 @@ nfsd4_write(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_writ
*p++ = nfssvc_boot.tv_usec;
status = nfsd_write(rqstp, current_fh, filp, write->wr_offset,
write->wr_vec, write->wr_vlen, write->wr_buflen,
rqstp->rq_vec, write->wr_vlen, write->wr_buflen,
&write->wr_how_written);
if (filp)
fput(filp);
......
......@@ -926,26 +926,26 @@ nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
printk(KERN_NOTICE "xdr error! (%s:%d)\n", __FILE__, __LINE__);
goto xdr_error;
}
write->wr_vec[0].iov_base = p;
write->wr_vec[0].iov_len = avail;
argp->rqstp->rq_vec[0].iov_base = p;
argp->rqstp->rq_vec[0].iov_len = avail;
v = 0;
len = write->wr_buflen;
while (len > write->wr_vec[v].iov_len) {
len -= write->wr_vec[v].iov_len;
while (len > argp->rqstp->rq_vec[v].iov_len) {
len -= argp->rqstp->rq_vec[v].iov_len;
v++;
write->wr_vec[v].iov_base = page_address(argp->pagelist[0]);
argp->rqstp->rq_vec[v].iov_base = page_address(argp->pagelist[0]);
argp->pagelist++;
if (argp->pagelen >= PAGE_SIZE) {
write->wr_vec[v].iov_len = PAGE_SIZE;
argp->rqstp->rq_vec[v].iov_len = PAGE_SIZE;
argp->pagelen -= PAGE_SIZE;
} else {
write->wr_vec[v].iov_len = argp->pagelen;
argp->rqstp->rq_vec[v].iov_len = argp->pagelen;
argp->pagelen -= len;
}
}
argp->end = (u32*) (write->wr_vec[v].iov_base + write->wr_vec[v].iov_len);
argp->p = (u32*) (write->wr_vec[v].iov_base + (XDR_QUADLEN(len) << 2));
write->wr_vec[v].iov_len = len;
argp->end = (u32*) (argp->rqstp->rq_vec[v].iov_base + argp->rqstp->rq_vec[v].iov_len);
argp->p = (u32*) (argp->rqstp->rq_vec[v].iov_base + (XDR_QUADLEN(len) << 2));
argp->rqstp->rq_vec[v].iov_len = len;
write->wr_vlen = v+1;
DECODE_TAIL;
......@@ -2063,9 +2063,9 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, int nfserr,
v = 0;
while (len > 0) {
pn = resp->rqstp->rq_resused++;
read->rd_iov[v].iov_base =
resp->rqstp->rq_vec[v].iov_base =
page_address(resp->rqstp->rq_respages[pn]);
read->rd_iov[v].iov_len =
resp->rqstp->rq_vec[v].iov_len =
len < PAGE_SIZE ? len : PAGE_SIZE;
v++;
len -= PAGE_SIZE;
......@@ -2073,7 +2073,7 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, int nfserr,
read->rd_vlen = v;
nfserr = nfsd_read(read->rd_rqstp, read->rd_fhp, read->rd_filp,
read->rd_offset, read->rd_iov, read->rd_vlen,
read->rd_offset, resp->rqstp->rq_vec, read->rd_vlen,
&maxcount);
if (nfserr == nfserr_symlink)
......
......@@ -159,7 +159,7 @@ nfsd_proc_read(struct svc_rqst *rqstp, struct nfsd_readargs *argp,
resp->count = argp->count;
nfserr = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh), NULL,
argp->offset,
argp->vec, argp->vlen,
rqstp->rq_vec, argp->vlen,
&resp->count);
if (nfserr) return nfserr;
......@@ -185,7 +185,7 @@ nfsd_proc_write(struct svc_rqst *rqstp, struct nfsd_writeargs *argp,
nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh), NULL,
argp->offset,
argp->vec, argp->vlen,
rqstp->rq_vec, argp->vlen,
argp->len,
&stable);
return nfsd_return_attrs(nfserr, resp);
......
......@@ -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
......
......@@ -30,7 +30,6 @@ struct nfsd_readargs {
struct svc_fh fh;
__u32 offset;
__u32 count;
struct kvec vec[RPCSVC_MAXPAGES];
int vlen;
};
......@@ -38,7 +37,6 @@ struct nfsd_writeargs {
svc_fh fh;
__u32 offset;
int len;
struct kvec vec[RPCSVC_MAXPAGES];
int vlen;
};
......
......@@ -33,7 +33,6 @@ struct nfsd3_readargs {
struct svc_fh fh;
__u64 offset;
__u32 count;
struct kvec vec[RPCSVC_MAXPAGES];
int vlen;
};
......@@ -43,7 +42,6 @@ struct nfsd3_writeargs {
__u32 count;
int stable;
__u32 len;
struct kvec vec[RPCSVC_MAXPAGES];
int vlen;
};
......
......@@ -241,7 +241,6 @@ struct nfsd4_read {
stateid_t rd_stateid; /* request */
u64 rd_offset; /* request */
u32 rd_length; /* request */
struct kvec rd_iov[RPCSVC_MAXPAGES];
int rd_vlen;
struct file *rd_filp;
......@@ -326,7 +325,6 @@ struct nfsd4_write {
u64 wr_offset; /* request */
u32 wr_stable_how; /* request */
u32 wr_buflen; /* request */
struct kvec wr_vec[RPCSVC_MAXPAGES]; /* request */
int wr_vlen;
u32 wr_bytes_written; /* response */
......
......@@ -192,6 +192,8 @@ struct svc_rqst {
struct page * *rq_respages; /* points into rq_pages */
int rq_resused; /* number of pages used for result */
struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
__be32 rq_xid; /* transmission id */
u32 rq_prog; /* program number */
u32 rq_vers; /* program version */
......
......@@ -955,7 +955,7 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
struct svc_sock *svsk = rqstp->rq_sock;
struct svc_serv *serv = svsk->sk_server;
int len;
struct kvec vec[RPCSVC_MAXPAGES];
struct kvec *vec;
int pnum, vlen;
dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
......@@ -1053,6 +1053,7 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
len = svsk->sk_reclen;
set_bit(SK_DATA, &svsk->sk_flags);
vec = rqstp->rq_vec;
vec[0] = rqstp->rq_arg.head[0];
vlen = PAGE_SIZE;
pnum = 1;
......
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