#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/sched.h>
-#include <linux/vmalloc.h>
#include <linux/kmemleak.h>
#include "delegation.h"
/* Perform conversion from xdr to cache array */
static
int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
- void *xdr_page, struct page *page, unsigned int buflen)
+ struct page **xdr_pages, struct page *page, unsigned int buflen)
{
struct xdr_stream stream;
- struct xdr_buf buf;
- __be32 *ptr = xdr_page;
+ struct xdr_buf buf = {
+ .pages = xdr_pages,
+ .page_len = buflen,
+ .buflen = buflen,
+ .len = buflen,
+ };
+ struct page *scratch;
struct nfs_cache_array *array;
unsigned int count = 0;
int status;
- buf.head->iov_base = xdr_page;
- buf.head->iov_len = buflen;
- buf.tail->iov_len = 0;
- buf.page_base = 0;
- buf.page_len = 0;
- buf.buflen = buf.head->iov_len;
- buf.len = buf.head->iov_len;
-
- xdr_init_decode(&stream, &buf, ptr);
+ scratch = alloc_page(GFP_KERNEL);
+ if (scratch == NULL)
+ return -ENOMEM;
+ xdr_init_decode(&stream, &buf, NULL);
+ xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
do {
status = xdr_decode(desc, entry, &stream);
} else
status = PTR_ERR(array);
}
+
+ put_page(scratch);
return status;
}
void nfs_readdir_free_large_page(void *ptr, struct page **pages,
unsigned int npages)
{
- vm_unmap_ram(ptr, npages);
nfs_readdir_free_pagearray(pages, npages);
}
* to nfs_readdir_free_large_page
*/
static
-void *nfs_readdir_large_page(struct page **pages, unsigned int npages)
+int nfs_readdir_large_page(struct page **pages, unsigned int npages)
{
- void *ptr;
unsigned int i;
for (i = 0; i < npages; i++) {
goto out_freepages;
pages[i] = page;
}
+ return 0;
- ptr = vm_map_ram(pages, npages, 0, PAGE_KERNEL);
- if (!IS_ERR_OR_NULL(ptr))
- return ptr;
out_freepages:
nfs_readdir_free_pagearray(pages, i);
- return NULL;
+ return -ENOMEM;
}
static
memset(array, 0, sizeof(struct nfs_cache_array));
array->eof_index = -1;
- pages_ptr = nfs_readdir_large_page(pages, array_size);
- if (!pages_ptr)
+ status = nfs_readdir_large_page(pages, array_size);
+ if (status < 0)
goto out_release_array;
do {
unsigned int pglen;
if (status < 0)
break;
pglen = status;
- status = nfs_readdir_page_filler(desc, &entry, pages_ptr, page, pglen);
+ status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
if (status < 0) {
if (status == -ENOSPC)
status = 0;
}
EXPORT_SYMBOL_GPL(xdr_write_pages);
+static void xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,
+ __be32 *p, unsigned int len)
+{
+ if (len > iov->iov_len)
+ len = iov->iov_len;
+ if (p == NULL)
+ p = (__be32*)iov->iov_base;
+ xdr->p = p;
+ xdr->end = (__be32*)(iov->iov_base + len);
+ xdr->iov = iov;
+ xdr->page_ptr = NULL;
+}
+
+static int xdr_set_page_base(struct xdr_stream *xdr,
+ unsigned int base, unsigned int len)
+{
+ unsigned int pgnr;
+ unsigned int maxlen;
+ unsigned int pgoff;
+ unsigned int pgend;
+ void *kaddr;
+
+ maxlen = xdr->buf->page_len;
+ if (base >= maxlen)
+ return -EINVAL;
+ maxlen -= base;
+ if (len > maxlen)
+ len = maxlen;
+
+ base += xdr->buf->page_base;
+
+ pgnr = base >> PAGE_SHIFT;
+ xdr->page_ptr = &xdr->buf->pages[pgnr];
+ kaddr = page_address(*xdr->page_ptr);
+
+ pgoff = base & ~PAGE_MASK;
+ xdr->p = (__be32*)(kaddr + pgoff);
+
+ pgend = pgoff + len;
+ if (pgend > PAGE_SIZE)
+ pgend = PAGE_SIZE;
+ xdr->end = (__be32*)(kaddr + pgend);
+ xdr->iov = NULL;
+ return 0;
+}
+
+static void xdr_set_next_page(struct xdr_stream *xdr)
+{
+ unsigned int newbase;
+
+ newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT;
+ newbase -= xdr->buf->page_base;
+
+ if (xdr_set_page_base(xdr, newbase, PAGE_SIZE) < 0)
+ xdr_set_iov(xdr, xdr->buf->tail, NULL, xdr->buf->len);
+}
+
+static bool xdr_set_next_buffer(struct xdr_stream *xdr)
+{
+ if (xdr->page_ptr != NULL)
+ xdr_set_next_page(xdr);
+ else if (xdr->iov == xdr->buf->head) {
+ if (xdr_set_page_base(xdr, 0, PAGE_SIZE) < 0)
+ xdr_set_iov(xdr, xdr->buf->tail, NULL, xdr->buf->len);
+ }
+ return xdr->p != xdr->end;
+}
+
/**
* xdr_init_decode - Initialize an xdr_stream for decoding data.
* @xdr: pointer to xdr_stream struct
*/
void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p)
{
- struct kvec *iov = buf->head;
- unsigned int len = iov->iov_len;
-
- if (len > buf->len)
- len = buf->len;
xdr->buf = buf;
- xdr->iov = iov;
- xdr->p = p;
- xdr->end = (__be32 *)((char *)iov->iov_base + len);
+ xdr->scratch.iov_base = NULL;
+ xdr->scratch.iov_len = 0;
+ if (buf->head[0].iov_len != 0)
+ xdr_set_iov(xdr, buf->head, p, buf->len);
+ else if (buf->page_len != 0)
+ xdr_set_page_base(xdr, 0, buf->len);
}
EXPORT_SYMBOL_GPL(xdr_init_decode);
-/**
- * xdr_inline_peek - Allow read-ahead in the XDR data stream
- * @xdr: pointer to xdr_stream struct
- * @nbytes: number of bytes of data to decode
- *
- * Check if the input buffer is long enough to enable us to decode
- * 'nbytes' more bytes of data starting at the current position.
- * If so return the current pointer without updating the current
- * pointer position.
- */
-__be32 * xdr_inline_peek(struct xdr_stream *xdr, size_t nbytes)
+static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
{
__be32 *p = xdr->p;
__be32 *q = p + XDR_QUADLEN(nbytes);
if (unlikely(q > xdr->end || q < p))
return NULL;
+ xdr->p = q;
return p;
}
-EXPORT_SYMBOL_GPL(xdr_inline_peek);
/**
- * xdr_inline_decode - Retrieve non-page XDR data to decode
+ * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
+ * @xdr: pointer to xdr_stream struct
+ * @buf: pointer to an empty buffer
+ * @buflen: size of 'buf'
+ *
+ * The scratch buffer is used when decoding from an array of pages.
+ * If an xdr_inline_decode() call spans across page boundaries, then
+ * we copy the data into the scratch buffer in order to allow linear
+ * access.
+ */
+void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
+{
+ xdr->scratch.iov_base = buf;
+ xdr->scratch.iov_len = buflen;
+}
+EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer);
+
+static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes)
+{
+ __be32 *p;
+ void *cpdest = xdr->scratch.iov_base;
+ size_t cplen = (char *)xdr->end - (char *)xdr->p;
+
+ if (nbytes > xdr->scratch.iov_len)
+ return NULL;
+ memcpy(cpdest, xdr->p, cplen);
+ cpdest += cplen;
+ nbytes -= cplen;
+ if (!xdr_set_next_buffer(xdr))
+ return NULL;
+ p = __xdr_inline_decode(xdr, nbytes);
+ if (p == NULL)
+ return NULL;
+ memcpy(cpdest, p, nbytes);
+ return xdr->scratch.iov_base;
+}
+
+/**
+ * xdr_inline_decode - Retrieve XDR data to decode
* @xdr: pointer to xdr_stream struct
* @nbytes: number of bytes of data to decode
*
*/
__be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
{
- __be32 *p = xdr->p;
- __be32 *q = p + XDR_QUADLEN(nbytes);
+ __be32 *p;
- if (unlikely(q > xdr->end || q < p))
+ if (nbytes == 0)
+ return xdr->p;
+ if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
return NULL;
- xdr->p = q;
- return p;
+ p = __xdr_inline_decode(xdr, nbytes);
+ if (p != NULL)
+ return p;
+ return xdr_copy_to_scratch(xdr, nbytes);
}
EXPORT_SYMBOL_GPL(xdr_inline_decode);
*/
void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
{
- char * kaddr = page_address(xdr->buf->pages[0]);
xdr_read_pages(xdr, len);
/*
* Position current pointer at beginning of tail, and
* set remaining message length.
*/
- if (len > PAGE_CACHE_SIZE - xdr->buf->page_base)
- len = PAGE_CACHE_SIZE - xdr->buf->page_base;
- xdr->p = (__be32 *)(kaddr + xdr->buf->page_base);
- xdr->end = (__be32 *)((char *)xdr->p + len);
+ xdr_set_page_base(xdr, 0, len);
}
EXPORT_SYMBOL_GPL(xdr_enter_page);
projects / users / willy / pagecache.git / commitdiff