Commit 3b2a09f1 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Don't discard readdir results 



If a readdir call returns more data than we can fit into one page
cache page, then allocate a new one for that data rather than
discarding the data.

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 1f1d4aa4

fs/nfs/dir.c

+42 −4
Original line number Diff line number Diff line
@@ -320,6 +320,26 @@ static void nfs_readdir_page_set_eof(struct page *page) 
	kunmap_atomic(array);

}



static void nfs_readdir_page_unlock_and_put(struct page *page)

{

	unlock_page(page);

	put_page(page);

}



static struct page *nfs_readdir_page_get_next(struct address_space *mapping,

					      pgoff_t index, u64 cookie)

{

	struct page *page;



	page = nfs_readdir_page_get_locked(mapping, index, cookie);

	if (page) {

		if (nfs_readdir_page_last_cookie(page) == cookie)

			return page;

		nfs_readdir_page_unlock_and_put(page);

	}

	return NULL;

}



static inline

int is_32bit_api(void)

{
@@ -637,13 +657,15 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry, 
}



/* Perform conversion from xdr to cache array */

static

int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,

				struct page **xdr_pages, struct page *page, unsigned int buflen)

static int nfs_readdir_page_filler(struct nfs_readdir_descriptor *desc,

				   struct nfs_entry *entry,

				   struct page **xdr_pages,

				   struct page *fillme, unsigned int buflen)

{

	struct address_space *mapping = desc->file->f_mapping;

	struct xdr_stream stream;

	struct xdr_buf buf;

	struct page *scratch;

	struct page *scratch, *new, *page = fillme;

	int status;



	scratch = alloc_page(GFP_KERNEL);
@@ -666,6 +688,19 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en 
					desc->dir_verifier);



		status = nfs_readdir_add_to_array(entry, page);

		if (status != -ENOSPC)

			continue;



		if (page->mapping != mapping)

			break;

		new = nfs_readdir_page_get_next(mapping, page->index + 1,

						entry->prev_cookie);

		if (!new)

			break;

		if (page != fillme)

			nfs_readdir_page_unlock_and_put(page);

		page = new;

		status = nfs_readdir_add_to_array(entry, page);

	} while (!status && !entry->eof);



	switch (status) {
@@ -681,6 +716,9 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en 
		break;

	}



	if (page != fillme)

		nfs_readdir_page_unlock_and_put(page);



	put_page(scratch);

	return status;

}