Commit 1f1d4aa4 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Clean up directory array handling 



Refactor to use pagecache_get_page() so that we can fill the page
in multiple stages.

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 972bcdf2

fs/nfs/dir.c

+77 −61
Original line number Diff line number Diff line
@@ -149,7 +149,7 @@ typedef struct nfs_readdir_descriptor { 
	struct file	*file;

	struct page	*page;

	struct dir_context *ctx;

	unsigned long	page_index;

	pgoff_t		page_index;

	u64		dir_cookie;

	u64		last_cookie;

	u64		dup_cookie;
@@ -166,13 +166,18 @@ typedef struct nfs_readdir_descriptor { 
	bool eof;

} nfs_readdir_descriptor_t;



static

void nfs_readdir_init_array(struct page *page)

static void nfs_readdir_array_init(struct nfs_cache_array *array)

{

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

}



static void nfs_readdir_page_init_array(struct page *page, u64 last_cookie)

{

	struct nfs_cache_array *array;



	array = kmap_atomic(page);

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

	nfs_readdir_array_init(array);

	array->last_cookie = last_cookie;

	kunmap_atomic(array);

}
@@ -188,7 +193,7 @@ void nfs_readdir_clear_array(struct page *page) 
	array = kmap_atomic(page);

	for (i = 0; i < array->size; i++)

		kfree(array->array[i].string.name);

	array->size = 0;

	nfs_readdir_array_init(array);

	kunmap_atomic(array);

}
@@ -268,6 +273,44 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) 
	return ret;

}



static struct page *nfs_readdir_page_get_locked(struct address_space *mapping,

						pgoff_t index, u64 last_cookie)

{

	struct page *page;



	page = grab_cache_page(mapping, index);

	if (page && !PageUptodate(page)) {

		nfs_readdir_page_init_array(page, last_cookie);

		if (invalidate_inode_pages2_range(mapping, index + 1, -1) < 0)

			nfs_zap_mapping(mapping->host, mapping);

		SetPageUptodate(page);

	}



	return page;

}



static u64 nfs_readdir_page_last_cookie(struct page *page)

{

	struct nfs_cache_array *array;

	u64 ret;



	array = kmap_atomic(page);

	ret = array->last_cookie;

	kunmap_atomic(array);

	return ret;

}



static bool nfs_readdir_page_needs_filling(struct page *page)

{

	struct nfs_cache_array *array;

	bool ret;



	array = kmap_atomic(page);

	ret = !nfs_readdir_array_is_full(array);

	kunmap_atomic(array);

	return ret;

}



static void nfs_readdir_page_set_eof(struct page *page)

{

	struct nfs_cache_array *array;
@@ -682,10 +725,8 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, 
	int status = -ENOMEM;

	unsigned int array_size = ARRAY_SIZE(pages);



	nfs_readdir_init_array(page);



	entry.prev_cookie = 0;

	entry.cookie = desc->last_cookie;

	entry.cookie = nfs_readdir_page_last_cookie(page);

	entry.eof = 0;

	entry.fh = nfs_alloc_fhandle();

	entry.fattr = nfs_alloc_fattr();
@@ -730,48 +771,25 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, 
	return status;

}



/*

 * Now we cache directories properly, by converting xdr information

 * to an array that can be used for lookups later.  This results in

 * fewer cache pages, since we can store more information on each page.

 * We only need to convert from xdr once so future lookups are much simpler

 */

static

int nfs_readdir_filler(void *data, struct page* page)

static void nfs_readdir_page_put(struct nfs_readdir_descriptor *desc)

{

	nfs_readdir_descriptor_t *desc = data;

	struct inode	*inode = file_inode(desc->file);

	int ret;



	ret = nfs_readdir_xdr_to_array(desc, page, inode);

	if (ret < 0)

		goto error;

	SetPageUptodate(page);



	if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {

		/* Should never happen */

		nfs_zap_mapping(inode, inode->i_mapping);

	}

	unlock_page(page);

	return 0;

 error:

	nfs_readdir_clear_array(page);

	unlock_page(page);

	return ret;

	put_page(desc->page);

	desc->page = NULL;

}



static

void cache_page_release(nfs_readdir_descriptor_t *desc)

static void

nfs_readdir_page_unlock_and_put_cached(struct nfs_readdir_descriptor *desc)

{

	put_page(desc->page);

	desc->page = NULL;

	unlock_page(desc->page);

	nfs_readdir_page_put(desc);

}



static

struct page *get_cache_page(nfs_readdir_descriptor_t *desc)

static struct page *

nfs_readdir_page_get_cached(struct nfs_readdir_descriptor *desc)

{

	return read_cache_page(desc->file->f_mapping, desc->page_index,

			nfs_readdir_filler, desc);

	return nfs_readdir_page_get_locked(desc->file->f_mapping,

					   desc->page_index,

					   desc->last_cookie);

}



/*
@@ -785,23 +803,21 @@ int find_and_lock_cache_page(nfs_readdir_descriptor_t *desc) 
	struct nfs_inode *nfsi = NFS_I(inode);

	int res;



	desc->page = get_cache_page(desc);

	if (IS_ERR(desc->page))

		return PTR_ERR(desc->page);

	res = lock_page_killable(desc->page);

	if (res != 0)

	desc->page = nfs_readdir_page_get_cached(desc);

	if (!desc->page)

		return -ENOMEM;

	if (nfs_readdir_page_needs_filling(desc->page)) {

		res = nfs_readdir_xdr_to_array(desc, desc->page, inode);

		if (res < 0)

			goto error;

	res = -EAGAIN;

	if (desc->page->mapping != NULL) {

	}

	res = nfs_readdir_search_array(desc);

	if (res == 0) {

		nfsi->page_index = desc->page_index;

		return 0;

	}

	}

	unlock_page(desc->page);

error:

	cache_page_release(desc);

	nfs_readdir_page_unlock_and_put_cached(desc);

	return res;

}
@@ -896,6 +912,7 @@ int uncached_readdir(nfs_readdir_descriptor_t *desc) 
	desc->page = page;

	desc->duped = 0;



	nfs_readdir_page_init_array(page, desc->dir_cookie);

	status = nfs_readdir_xdr_to_array(desc, page, inode);

	if (status < 0)

		goto out_release;
@@ -904,7 +921,7 @@ int uncached_readdir(nfs_readdir_descriptor_t *desc) 


 out_release:

	nfs_readdir_clear_array(desc->page);

	cache_page_release(desc);

	nfs_readdir_page_put(desc);

 out:

	dfprintk(DIRCACHE, "NFS: %s: returns %d\n",

			__func__, status);
@@ -976,8 +993,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx) 
			break;



		res = nfs_do_filldir(desc);

		unlock_page(desc->page);

		cache_page_release(desc);

		nfs_readdir_page_unlock_and_put_cached(desc);

		if (res < 0)

			break;

	} while (!desc->eof);