From: NeilBrown .. 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 Signed-off-by: Andrew Morton --- fs/nfsd/nfs3proc.c | 4 ++-- fs/nfsd/nfs3xdr.c | 22 +++++++++++----------- fs/nfsd/nfs4proc.c | 2 +- fs/nfsd/nfs4xdr.c | 26 +++++++++++++------------- fs/nfsd/nfsproc.c | 4 ++-- fs/nfsd/nfsxdr.c | 22 +++++++++++----------- include/linux/nfsd/xdr.h | 2 -- include/linux/nfsd/xdr3.h | 2 -- include/linux/nfsd/xdr4.h | 2 -- include/linux/sunrpc/svc.h | 2 ++ net/sunrpc/svcsock.c | 3 ++- 11 files changed, 44 insertions(+), 47 deletions(-) diff -puN fs/nfsd/nfs3proc.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom fs/nfsd/nfs3proc.c --- a/fs/nfsd/nfs3proc.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/fs/nfsd/nfs3proc.c @@ -180,7 +180,7 @@ nfsd3_proc_read(struct svc_rqst *rqstp, 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, 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; diff -puN fs/nfsd/nfs3xdr.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom fs/nfsd/nfs3xdr.c --- a/fs/nfsd/nfs3xdr.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/fs/nfsd/nfs3xdr.c @@ -344,9 +344,9 @@ nfs3svc_decode_readargs(struct svc_rqst 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->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 diff -puN fs/nfsd/nfs4proc.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom fs/nfsd/nfs4proc.c --- a/fs/nfsd/nfs4proc.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/fs/nfsd/nfs4proc.c @@ -646,7 +646,7 @@ nfsd4_write(struct svc_rqst *rqstp, stru *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); diff -puN fs/nfsd/nfs4xdr.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom fs/nfsd/nfs4xdr.c --- a/fs/nfsd/nfs4xdr.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/fs/nfsd/nfs4xdr.c @@ -927,26 +927,26 @@ nfsd4_decode_write(struct nfsd4_compound 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; @@ -2064,9 +2064,9 @@ nfsd4_encode_read(struct nfsd4_compoundr 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; @@ -2074,7 +2074,7 @@ nfsd4_encode_read(struct nfsd4_compoundr 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) diff -puN fs/nfsd/nfsproc.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom fs/nfsd/nfsproc.c --- a/fs/nfsd/nfsproc.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/fs/nfsd/nfsproc.c @@ -159,7 +159,7 @@ nfsd_proc_read(struct svc_rqst *rqstp, s 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, 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); diff -puN fs/nfsd/nfsxdr.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom fs/nfsd/nfsxdr.c --- a/fs/nfsd/nfsxdr.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/fs/nfsd/nfsxdr.c @@ -263,9 +263,9 @@ nfssvc_decode_readargs(struct svc_rqst * 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 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 diff -puN include/linux/nfsd/xdr.h~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom include/linux/nfsd/xdr.h --- a/include/linux/nfsd/xdr.h~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/include/linux/nfsd/xdr.h @@ -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; }; diff -puN include/linux/nfsd/xdr3.h~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom include/linux/nfsd/xdr3.h --- a/include/linux/nfsd/xdr3.h~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/include/linux/nfsd/xdr3.h @@ -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; }; diff -puN include/linux/nfsd/xdr4.h~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom include/linux/nfsd/xdr4.h --- a/include/linux/nfsd/xdr4.h~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/include/linux/nfsd/xdr4.h @@ -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 */ diff -puN include/linux/sunrpc/svc.h~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom include/linux/sunrpc/svc.h --- a/include/linux/sunrpc/svc.h~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/include/linux/sunrpc/svc.h @@ -175,6 +175,8 @@ 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.. */ + u32 rq_xid; /* transmission id */ u32 rq_prog; /* program number */ u32 rq_vers; /* program version */ diff -puN net/sunrpc/svcsock.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom net/sunrpc/svcsock.c --- a/net/sunrpc/svcsock.c~knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom +++ a/net/sunrpc/svcsock.c @@ -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; _