Commit b1e21c97 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Clean up readdir struct nfs_cache_array 



Since the 'eof_index' is only ever used as a flag, make it so.
Also add a flag to detect if the page has been completely filled.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: default avatarBenjamin Coddington <bcodding@redhat.com>
Tested-by: default avatarBenjamin Coddington <bcodding@redhat.com>
Tested-by: default avatarDave Wysochanski <dwysocha@redhat.com>
parent 2e7a4641

fs/nfs/dir.c

+49 −17
Original line number Diff line number Diff line
@@ -138,9 +138,10 @@ struct nfs_cache_array_entry { 
};



struct nfs_cache_array {

	int size;

	int eof_index;

	u64 last_cookie;

	unsigned int size;

	unsigned char page_full : 1,

		      page_is_eof : 1;

	struct nfs_cache_array_entry array[];

};
@@ -172,7 +173,6 @@ void nfs_readdir_init_array(struct page *page) 


	array = kmap_atomic(page);

	memset(array, 0, sizeof(struct nfs_cache_array));

	array->eof_index = -1;

	kunmap_atomic(array);

}
@@ -192,6 +192,17 @@ void nfs_readdir_clear_array(struct page *page) 
	kunmap_atomic(array);

}



static void nfs_readdir_array_set_eof(struct nfs_cache_array *array)

{

	array->page_is_eof = 1;

	array->page_full = 1;

}



static bool nfs_readdir_array_is_full(struct nfs_cache_array *array)

{

	return array->page_full;

}



/*

 * the caller is responsible for freeing qstr.name

 * when called by nfs_readdir_add_to_array, the strings will be freed in
@@ -213,6 +224,23 @@ int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int le 
	return 0;

}



/*

 * 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) {

		array->page_full = 1;

		return -ENOSPC;

	}

	return 0;

}



static

int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)

{
@@ -220,13 +248,11 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) 
	struct nfs_cache_array_entry *cache_entry;

	int ret;



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



	/* Check that this entry lies within the page bounds */

	ret = -ENOSPC;

	if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)

	ret = nfs_readdir_array_can_expand(array);

	if (ret)

		goto out;



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

	cache_entry->cookie = entry->prev_cookie;

	cache_entry->ino = entry->ino;

	cache_entry->d_type = entry->d_type;
@@ -236,12 +262,21 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) 
	array->last_cookie = entry->cookie;

	array->size++;

	if (entry->eof != 0)

		array->eof_index = array->size;

		nfs_readdir_array_set_eof(array);

out:

	kunmap(page);

	return ret;

}



static void nfs_readdir_page_set_eof(struct page *page)

{

	struct nfs_cache_array *array;



	array = kmap_atomic(page);

	nfs_readdir_array_set_eof(array);

	kunmap_atomic(array);

}



static inline

int is_32bit_api(void)

{
@@ -270,7 +305,7 @@ int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descri 
	if (diff < 0)

		goto out_eof;

	if (diff >= array->size) {

		if (array->eof_index >= 0)

		if (array->page_is_eof)

			goto out_eof;

		return -EAGAIN;

	}
@@ -334,7 +369,7 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des 
			return 0;

		}

	}

	if (array->eof_index >= 0) {

	if (array->page_is_eof) {

		status = -EBADCOOKIE;

		if (desc->dir_cookie == array->last_cookie)

			desc->eof = true;
@@ -566,7 +601,6 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en 
	struct xdr_stream stream;

	struct xdr_buf buf;

	struct page *scratch;

	struct nfs_cache_array *array;

	unsigned int count = 0;

	int status;
@@ -604,10 +638,8 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en 


out_nopages:

	if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {

		array = kmap(page);

		array->eof_index = array->size;

		nfs_readdir_page_set_eof(page);

		status = 0;

		kunmap(page);

	}



	put_page(scratch);
@@ -689,7 +721,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, 
				status = 0;

			break;

		}

	} while (array->eof_index < 0);

	} while (!nfs_readdir_array_is_full(array));



	nfs_readdir_free_pages(pages, array_size);

out_release_array:
@@ -825,7 +857,7 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc) 
		if (desc->duped != 0)

			desc->duped = 1;

	}

	if (array->eof_index >= 0)

	if (array->page_is_eof)

		desc->eof = true;



	kunmap(desc->page);