Convert the READ_BUF macro in nfs4xdr.c from open code to instead
use the new xdr_stream-style decoders already in use by the encode
side (and by the in-kernel NFS client implementation). Once this
conversion is done, each individual NFSv4 argument decoder can be
independently cleaned up to replace these macros with C code.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfsd/nfs4proc.c | 4 -
fs/nfsd/nfs4xdr.c | 181 ++++++--------------------------------------
fs/nfsd/xdr4.h | 10 --
include/linux/sunrpc/xdr.h | 2
net/sunrpc/xdr.c | 44 +++++++++++
5 files changed, 76 insertions(+), 165 deletions(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 9280740941db..dc5c9fb1888b 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1023,8 +1023,8 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
write->wr_how_written = write->wr_stable_how;
- nvecs = svc_fill_write_vector(rqstp, write->wr_pagelist,
- &write->wr_head, write->wr_buflen);
+ nvecs = svc_fill_write_vector(rqstp, write->wr_payload.pages,
+ write->wr_payload.head, write->wr_buflen);
WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec));
status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf,
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 6c3d45f68b75..26265d649c39 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -129,90 +129,13 @@ xdr_error: \
memcpy((x), p, nbytes); \
p += XDR_QUADLEN(nbytes); \
} while (0)
-
-/* READ_BUF, read_buf(): nbytes must be <= PAGE_SIZE */
-#define READ_BUF(nbytes) do { \
- if (nbytes <= (u32)((char *)argp->end - (char *)argp->p)) { \
- p = argp->p; \
- argp->p += XDR_QUADLEN(nbytes); \
- } else if (!(p = read_buf(argp, nbytes))) { \
- dprintk("NFSD: xdr error (%s:%d)\n", \
- __FILE__, __LINE__); \
- goto xdr_error; \
- } \
-} while (0)
-
-static void next_decode_page(struct nfsd4_compoundargs *argp)
-{
- argp->p = page_address(argp->pagelist[0]);
- argp->pagelist++;
- if (argp->pagelen < PAGE_SIZE) {
- argp->end = argp->p + XDR_QUADLEN(argp->pagelen);
- argp->pagelen = 0;
- } else {
- argp->end = argp->p + (PAGE_SIZE>>2);
- argp->pagelen -= PAGE_SIZE;
- }
-}
-
-static __be32 *read_buf(struct nfsd4_compoundargs *argp, u32 nbytes)
-{
- /* We want more bytes than seem to be available.
- * Maybe we need a new page, maybe we have just run out
- */
- unsigned int avail = (char *)argp->end - (char *)argp->p;
- __be32 *p;
-
- if (argp->pagelen == 0) {
- struct kvec *vec = &argp->rqstp->rq_arg.tail[0];
-
- if (!argp->tail) {
- argp->tail = true;
- avail = vec->iov_len;
- argp->p = vec->iov_base;
- argp->end = vec->iov_base + avail;
- }
-
- if (avail < nbytes)
- return NULL;
-
- p = argp->p;
- argp->p += XDR_QUADLEN(nbytes);
- return p;
- }
-
- if (avail + argp->pagelen < nbytes)
- return NULL;
- if (avail + PAGE_SIZE < nbytes) /* need more than a page !! */
- return NULL;
- /* ok, we can do it with the current plus the next page */
- if (nbytes <= sizeof(argp->tmp))
- p = argp->tmp;
- else {
- kfree(argp->tmpp);
- p = argp->tmpp = kmalloc(nbytes, GFP_KERNEL);
- if (!p)
- return NULL;
-
- }
- /*
- * The following memcpy is safe because read_buf is always
- * called with nbytes > avail, and the two cases above both
- * guarantee p points to at least nbytes bytes.
- */
- memcpy(p, argp->p, avail);
- next_decode_page(argp);
- memcpy(((char*)p)+avail, argp->p, (nbytes - avail));
- argp->p += XDR_QUADLEN(nbytes - avail);
- return p;
-}
-
-static unsigned int compoundargs_bytes_left(struct nfsd4_compoundargs *argp)
-{
- unsigned int this = (char *)argp->end - (char *)argp->p;
-
- return this + argp->pagelen;
-}
+#define READ_BUF(nbytes) \
+ do { \
+ p = xdr_inline_decode(argp->xdr,\
+ nbytes); \
+ if (!p) \
+ goto xdr_error; \
+ } while (0)
static int zero_clientid(clientid_t *clid)
{
@@ -259,44 +182,6 @@ 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
@@ -396,7 +281,7 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
READ_BUF(4); len += 4;
nace = be32_to_cpup(p++);
- if (nace > compoundargs_bytes_left(argp)/20)
+ if (nace > xdr_stream_remaining(argp->xdr) / sizeof(struct nfs4_ace))
/*
* Even with 4-byte names there wouldn't be
* space for that many aces; something fishy is
@@ -927,7 +812,7 @@ static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
{
- __be32 *p;
+ DECODE_HEAD;
READ_BUF(4);
o->len = be32_to_cpup(p++);
@@ -937,9 +822,8 @@ static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_ne
READ_BUF(o->len);
SAVEMEM(o->data, o->len);
- return nfs_ok;
-xdr_error:
- return nfserr_bad_xdr;
+
+ DECODE_TAIL;
}
static __be32
@@ -1317,10 +1201,8 @@ nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
goto xdr_error;
write->wr_buflen = be32_to_cpup(p++);
- status = svcxdr_construct_vector(argp, &write->wr_head,
- &write->wr_pagelist, write->wr_buflen);
- if (status)
- return status;
+ if (!xdr_stream_subsegment(argp->xdr, &write->wr_payload, write->wr_buflen))
+ goto xdr_error;
DECODE_TAIL;
}
@@ -1889,13 +1771,14 @@ nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
*/
/*
- * Decode data into buffer. Uses head and pages constructed by
- * svcxdr_construct_vector.
+ * Decode data into buffer.
*/
static __be32
-nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct kvec *head,
- struct page **pages, char **bufp, u32 buflen)
+nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
+ char **bufp, u32 buflen)
{
+ struct page **pages = xdr->pages;
+ struct kvec *head = xdr->head;
char *tmp, *dp;
u32 len;
@@ -2010,8 +1893,6 @@ nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
{
DECODE_HEAD;
u32 flags, maxcount, size;
- struct kvec head;
- struct page **pagelist;
READ_BUF(4);
flags = be32_to_cpup(p++);
@@ -2034,12 +1915,12 @@ nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
setxattr->setxa_len = size;
if (size > 0) {
- status = svcxdr_construct_vector(argp, &head, &pagelist, size);
- if (status)
- return status;
+ struct xdr_buf payload;
- status = nfsd4_vbuf_from_vector(argp, &head, pagelist,
- &setxattr->setxa_buf, size);
+ if (!xdr_stream_subsegment(argp->xdr, &payload, size))
+ goto xdr_error;
+ status = nfsd4_vbuf_from_vector(argp, &payload,
+ &setxattr->setxa_buf, size);
}
DECODE_TAIL;
@@ -5279,8 +5160,6 @@ void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
kfree(args->ops);
args->ops = args->iops;
}
- kfree(args->tmpp);
- args->tmpp = NULL;
while (args->to_free) {
struct svcxdr_tmpbuf *tb = args->to_free;
args->to_free = tb->next;
@@ -5293,19 +5172,11 @@ nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd4_compoundargs *args = rqstp->rq_argp;
- if (rqstp->rq_arg.head[0].iov_len % 4) {
- /* client is nuts */
- dprintk("%s: compound not properly padded! (peeraddr=%pISc xid=0x%x)",
- __func__, svc_addr(rqstp), be32_to_cpu(rqstp->rq_xid));
- return 0;
- }
- args->p = p;
- args->end = rqstp->rq_arg.head[0].iov_base + rqstp->rq_arg.head[0].iov_len;
- args->pagelist = rqstp->rq_arg.pages;
- args->pagelen = rqstp->rq_arg.page_len;
- args->tail = false;
+ /* svcxdr_tmp_alloc */
args->tmpp = NULL;
args->to_free = NULL;
+
+ args->xdr = &rqstp->rq_xdr_stream;
args->ops = args->iops;
args->rqstp = rqstp;
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 37f89ad5e992..0eb13bd603ea 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -419,8 +419,7 @@ struct nfsd4_write {
u64 wr_offset; /* request */
u32 wr_stable_how; /* request */
u32 wr_buflen; /* request */
- struct kvec wr_head;
- struct page ** wr_pagelist; /* request */
+ struct xdr_buf wr_payload; /* request */
u32 wr_bytes_written; /* response */
u32 wr_how_written; /* response */
@@ -696,15 +695,10 @@ struct svcxdr_tmpbuf {
struct nfsd4_compoundargs {
/* scratch variables for XDR decode */
- __be32 * p;
- __be32 * end;
- struct page ** pagelist;
- int pagelen;
- bool tail;
__be32 tmp[8];
__be32 * tmpp;
+ struct xdr_stream *xdr;
struct svcxdr_tmpbuf *to_free;
-
struct svc_rqst *rqstp;
u32 taglen;
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index abbb032de4e8..8f458addfcf0 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -259,6 +259,8 @@ extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
extern uint64_t xdr_align_data(struct xdr_stream *, uint64_t, uint32_t);
extern uint64_t xdr_expand_hole(struct xdr_stream *, uint64_t, uint64_t);
+extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
+ unsigned int len);
/**
* xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index c607744b3ea8..272c9d566e6a 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1407,6 +1407,50 @@ int xdr_buf_subsegment(const struct xdr_buf *buf, struct xdr_buf *subbuf,
}
EXPORT_SYMBOL_GPL(xdr_buf_subsegment);
+/**
+ * xdr_stream_subsegment - set @subbuf to a portion of @xdr
+ * @xdr: an xdr_stream set up for decoding
+ * @subbuf: the result buffer
+ * @nbytes: length of @xdr to extract, in bytes
+ *
+ * Sets up @subbuf to represent a portion of @xdr. The portion
+ * starts at the current offset in @xdr, and extends for a length
+ * of @nbytes. If this is successful, @xdr is advanced to the next
+ * position following that portion.
+ *
+ * Return values:
+ * %true: @subbuf has been initialized, and @xdr has been advanced.
+ * %false: a bounds error occurred; @xdr is unchanged.
+ */
+bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
+ unsigned int nbytes)
+{
+ unsigned int len, remaining, offset;
+
+ if (xdr_buf_subsegment(xdr->buf, subbuf, xdr_stream_pos(xdr), nbytes))
+ return false;
+
+ if (subbuf->head[0].iov_len)
+ __xdr_inline_decode(xdr, subbuf->head[0].iov_len);
+
+ remaining = subbuf->page_len;
+ offset = subbuf->page_base;
+ while (remaining) {
+ len = min_t(unsigned int, remaining, PAGE_SIZE);
+ len -= offset;
+
+ if (xdr->p == xdr->end)
+ xdr_set_next_buffer(xdr);
+ __xdr_inline_decode(xdr, len);
+
+ remaining -= len;
+ offset = 0;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(xdr_stream_subsegment);
+
/**
* xdr_buf_trim - lop at most "len" bytes off the end of "buf"
* @buf: buf to be trimmed
