Commit 0b2662b7 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Calculate page offsets algorithmically 



Instead of relying on counting the page offsets as we walk through the
page cache, switch to calculating them algorithmically.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 281f31b2

fs/nfs/dir.c

+13 −5
Original line number Diff line number Diff line
@@ -249,17 +249,20 @@ static const char *nfs_readdir_copy_name(const char *name, unsigned int len) 
	return ret;

}



static size_t nfs_readdir_array_maxentries(void)

{

	return (PAGE_SIZE - sizeof(struct nfs_cache_array)) /

	       sizeof(struct nfs_cache_array_entry);

}



/*

 * Check that the next array entry lies entirely within the page bounds

 */

static int nfs_readdir_array_can_expand(struct nfs_cache_array *array)

{

	struct nfs_cache_array_entry *cache_entry;



	if (array->page_full)

		return -ENOSPC;

	cache_entry = &array->array[array->size + 1];

	if ((char *)cache_entry - (char *)array > PAGE_SIZE) {

	if (array->size == nfs_readdir_array_maxentries()) {

		array->page_full = 1;

		return -ENOSPC;

	}
@@ -318,6 +321,11 @@ static struct page *nfs_readdir_page_get_locked(struct address_space *mapping, 
	return page;

}



static loff_t nfs_readdir_page_offset(struct page *page)

{

	return (loff_t)page->index * (loff_t)nfs_readdir_array_maxentries();

}



static u64 nfs_readdir_page_last_cookie(struct page *page)

{

	struct nfs_cache_array *array;
@@ -448,7 +456,7 @@ static int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, 
		if (array->array[i].cookie == desc->dir_cookie) {

			struct nfs_inode *nfsi = NFS_I(file_inode(desc->file));



			new_pos = desc->current_index + i;

			new_pos = nfs_readdir_page_offset(desc->page) + i;

			if (desc->attr_gencount != nfsi->attr_gencount ||

			    !nfs_readdir_inode_mapping_valid(nfsi)) {

				desc->duped = 0;