nfsd: split off the write decode code into a separate function

nfs4_decode_write has code to parse incoming XDR write data in to
a kvec head, and a list of pages.

Put this code in to a separate function, so that it can be used
later by the xattr code, for setxattr. No functional change.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Frank van der Linden 2020-06-23 22:39:21 +00:00 committed by Chuck Lever
parent cab8d289c5
commit 874c7b8ea5

View File

@ -257,6 +257,44 @@ svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
return p;
}
static __be32
svcxdr_construct_vector(struct nfsd4_compoundargs *argp, struct kvec *head,
struct page ***pagelist, u32 buflen)
{
int avail;
int len;
int pages;
/* Sorry .. no magic macros for this.. *
* READ_BUF(write->wr_buflen);
* SAVEMEM(write->wr_buf, write->wr_buflen);
*/
avail = (char *)argp->end - (char *)argp->p;
if (avail + argp->pagelen < buflen) {
dprintk("NFSD: xdr error (%s:%d)\n",
__FILE__, __LINE__);
return nfserr_bad_xdr;
}
head->iov_base = argp->p;
head->iov_len = avail;
*pagelist = argp->pagelist;
len = XDR_QUADLEN(buflen) << 2;
if (len >= avail) {
len -= avail;
pages = len >> PAGE_SHIFT;
argp->pagelist += pages;
argp->pagelen -= pages * PAGE_SIZE;
len -= pages * PAGE_SIZE;
next_decode_page(argp);
}
argp->p += XDR_QUADLEN(len);
return 0;
}
/**
* savemem - duplicate a chunk of memory for later processing
* @argp: NFSv4 compound argument structure to be freed with
@ -1265,8 +1303,6 @@ nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify
static __be32
nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
{
int avail;
int len;
DECODE_HEAD;
status = nfsd4_decode_stateid(argp, &write->wr_stateid);
@ -1279,34 +1315,10 @@ nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
goto xdr_error;
write->wr_buflen = be32_to_cpup(p++);
/* Sorry .. no magic macros for this.. *
* READ_BUF(write->wr_buflen);
* SAVEMEM(write->wr_buf, write->wr_buflen);
*/
avail = (char*)argp->end - (char*)argp->p;
if (avail + argp->pagelen < write->wr_buflen) {
dprintk("NFSD: xdr error (%s:%d)\n",
__FILE__, __LINE__);
goto xdr_error;
}
write->wr_head.iov_base = p;
write->wr_head.iov_len = avail;
write->wr_pagelist = argp->pagelist;
len = XDR_QUADLEN(write->wr_buflen) << 2;
if (len >= avail) {
int pages;
len -= avail;
pages = len >> PAGE_SHIFT;
argp->pagelist += pages;
argp->pagelen -= pages * PAGE_SIZE;
len -= pages * PAGE_SIZE;
next_decode_page(argp);
}
argp->p += XDR_QUADLEN(len);
status = svcxdr_construct_vector(argp, &write->wr_head,
&write->wr_pagelist, write->wr_buflen);
if (status)
return status;
DECODE_TAIL;
}