NFS: readdir with vmapped pages

[pandora-kernel.git] / fs / nfs / dir.c

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 88cbcda..5d7da3a 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -33,6 +33,7 @@
 #include <linux/namei.h>
 #include <linux/mount.h>
 #include <linux/sched.h>
+#include <linux/vmalloc.h>
 
 #include "delegation.h"
 #include "iostat.h"
@@ -327,7 +328,7 @@ out:
 
 /* Fill a page with xdr information before transferring to the cache page */
 static
-int nfs_readdir_xdr_filler(struct page *xdr_page, nfs_readdir_descriptor_t *desc,
+int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
                        struct nfs_entry *entry, struct file *file, struct inode *inode)
 {
        struct rpc_cred *cred = nfs_file_cred(file);
@@ -337,7 +338,7 @@ int nfs_readdir_xdr_filler(struct page *xdr_page, nfs_readdir_descriptor_t *desc
  again:
        timestamp = jiffies;
        gencount = nfs_inc_attr_generation_counter();
-       error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, xdr_page,
+       error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages,
                                          NFS_SERVER(inode)->dtsize, desc->plus);
        if (error < 0) {
                /* We requested READDIRPLUS, but the server doesn't grok it */
@@ -436,11 +437,11 @@ out:
 /* Perform conversion from xdr to cache array */
 static
 void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
-                               struct page *xdr_page, struct page *page, unsigned int buflen)
+                               void *xdr_page, struct page *page, unsigned int buflen)
 {
        struct xdr_stream stream;
        struct xdr_buf buf;
-       __be32 *ptr = kmap(xdr_page);
+       __be32 *ptr = xdr_page;
 
        buf.head->iov_base = xdr_page;
        buf.head->iov_len = buflen;
@@ -458,18 +459,59 @@ void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *e
                if (desc->plus == 1)
                        nfs_prime_dcache(desc->file->f_path.dentry, entry);
        }
-       kunmap(xdr_page);
+}
+
+static
+void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
+{
+       unsigned int i;
+       for (i = 0; i < npages; i++)
+               put_page(pages[i]);
+}
+
+static
+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);
+}
+
+/*
+ * nfs_readdir_large_page will allocate pages that must be freed with a call
+ * to nfs_readdir_free_large_page
+ */
+static
+void *nfs_readdir_large_page(struct page **pages, unsigned int npages)
+{
+       void *ptr;
+       unsigned int i;
+
+       for (i = 0; i < npages; i++) {
+               struct page *page = alloc_page(GFP_KERNEL);
+               if (page == NULL)
+                       goto out_freepages;
+               pages[i] = page;
+       }
+
+       ptr = vm_map_ram(pages, NFS_MAX_READDIR_PAGES, 0, PAGE_KERNEL);
+       if (!IS_ERR_OR_NULL(ptr))
+               return ptr;
+out_freepages:
+       nfs_readdir_free_pagearray(pages, i);
+       return NULL;
 }
 
 static
 int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
 {
-       struct page *xdr_page;
+       struct page *pages[NFS_MAX_READDIR_PAGES];
+       void *pages_ptr = NULL;
        struct nfs_entry entry;
        struct file     *file = desc->file;
        struct nfs_cache_array *array;
        int status = 0;
-       unsigned int array_size = 1;
+       unsigned int array_size = ARRAY_SIZE(pages);
 
        entry.prev_cookie = 0;
        entry.cookie = *desc->dir_cookie;
@@ -483,18 +525,18 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
        memset(array, 0, sizeof(struct nfs_cache_array));
        array->eof_index = -1;
 
-       xdr_page = alloc_page(GFP_KERNEL);
-       if (!xdr_page)
+       pages_ptr = nfs_readdir_large_page(pages, array_size);
+       if (!pages_ptr)
                goto out_release_array;
        do {
-               status = nfs_readdir_xdr_filler(xdr_page, desc, &entry, file, inode);
+               status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
 
                if (status < 0)
                        break;
-               nfs_readdir_page_filler(desc, &entry, xdr_page, page, array_size * PAGE_SIZE);
+               nfs_readdir_page_filler(desc, &entry, pages_ptr, page, array_size * PAGE_SIZE);
        } while (array->eof_index < 0 && array->size < MAX_READDIR_ARRAY);
 
-       put_page(xdr_page);
+       nfs_readdir_free_large_page(pages_ptr, pages, array_size);
 out_release_array:
        nfs_readdir_release_array(page);
 out: