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Commit 8cd51a0c authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Fix a couple of regressions in readdir. 



Fix up the issue that array->eof_index needs to be able to be set
even if array->size == 0.

Ensure that we catch all important memory allocation error conditions
and/or kmap() failures.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 23ebbd9a

fs/nfs/dir.c

+56 −34
Original line number Diff line number Diff line
@@ -194,9 +194,13 @@ typedef struct { 
static

struct nfs_cache_array *nfs_readdir_get_array(struct page *page)

{

	void *ptr;

	if (page == NULL)

		return ERR_PTR(-EIO);

	return (struct nfs_cache_array *)kmap(page);

	ptr = kmap(page);

	if (ptr == NULL)

		return ERR_PTR(-ENOMEM);

	return ptr;

}



static
@@ -213,6 +217,9 @@ int nfs_readdir_clear_array(struct page *page, gfp_t mask) 
{

	struct nfs_cache_array *array = nfs_readdir_get_array(page);

	int i;



	if (IS_ERR(array))

		return PTR_ERR(array);

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

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

	nfs_readdir_release_array(page);
@@ -244,7 +251,7 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) 


	if (IS_ERR(array))

		return PTR_ERR(array);

	ret = -EIO;

	ret = -ENOSPC;

	if (array->size >= MAX_READDIR_ARRAY)

		goto out;
@@ -255,9 +262,9 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) 
	if (ret)

		goto out;

	array->last_cookie = entry->cookie;

	array->size++;

	if (entry->eof == 1)

		array->eof_index = array->size;

	array->size++;

out:

	nfs_readdir_release_array(page);

	return ret;
@@ -272,7 +279,7 @@ 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->eof_index >= 0)

			goto out_eof;

		desc->current_index += array->size;

		return -EAGAIN;
@@ -281,8 +288,6 @@ int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descri 
	index = (unsigned int)diff;

	*desc->dir_cookie = array->array[index].cookie;

	desc->cache_entry_index = index;

	if (index == array->eof_index)

		desc->eof = 1;

	return 0;

out_eof:

	desc->eof = 1;
@@ -296,17 +301,17 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des 
	int status = -EAGAIN;



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

		if (i == array->eof_index) {

			desc->eof = 1;

			status = -EBADCOOKIE;

		}

		if (array->array[i].cookie == *desc->dir_cookie) {

			desc->cache_entry_index = i;

			status = 0;

			break;

			goto out;

		}

	}



	if (i == array->eof_index) {

		desc->eof = 1;

		status = -EBADCOOKIE;

	}

out:

	return status;

}
@@ -449,7 +454,7 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) 


/* Perform conversion from xdr to cache array */

static

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

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

				void *xdr_page, struct page *page, unsigned int buflen)

{

	struct xdr_stream stream;
@@ -471,22 +476,30 @@ void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *e 


	do {

		status = xdr_decode(desc, entry, &stream);

		if (status != 0)

		if (status != 0) {

			if (status == -EAGAIN)

				status = 0;

			break;

		}



		if (nfs_readdir_add_to_array(entry, page) == -1)

			break;

		if (desc->plus == 1)

			nfs_prime_dcache(desc->file->f_path.dentry, entry);



		status = nfs_readdir_add_to_array(entry, page);

		if (status != 0)

			break;

	} while (!entry->eof);



	if (status == -EBADCOOKIE && entry->eof) {

		array = nfs_readdir_get_array(page);

		array->eof_index = array->size - 1;

		if (!IS_ERR(array)) {

			array->eof_index = array->size;

			status = 0;

			nfs_readdir_release_array(page);

		}

	}

	return status;

}



static

void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
@@ -537,7 +550,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, 
	struct nfs_entry entry;

	struct file	*file = desc->file;

	struct nfs_cache_array *array;

	int status = 0;

	int status = -ENOMEM;

	unsigned int array_size = ARRAY_SIZE(pages);



	entry.prev_cookie = 0;
@@ -549,6 +562,10 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, 
		goto out;



	array = nfs_readdir_get_array(page);

	if (IS_ERR(array)) {

		status = PTR_ERR(array);

		goto out;

	}

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

	array->eof_index = -1;
@@ -560,8 +577,13 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, 


		if (status < 0)

			break;

		nfs_readdir_page_filler(desc, &entry, pages_ptr, page, array_size * PAGE_SIZE);

	} while (array->eof_index < 0 && array->size < MAX_READDIR_ARRAY);

		status = nfs_readdir_page_filler(desc, &entry, pages_ptr, page, array_size * PAGE_SIZE);

		if (status < 0) {

			if (status == -ENOSPC)

				status = 0;

			break;

		}

	} while (array->eof_index < 0);



	nfs_readdir_free_large_page(pages_ptr, pages, array_size);

out_release_array:
@@ -582,8 +604,10 @@ static 
int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)

{

	struct inode	*inode = desc->file->f_path.dentry->d_inode;

	int ret;



	if (nfs_readdir_xdr_to_array(desc, page, inode) < 0)

	ret = nfs_readdir_xdr_to_array(desc, page, inode);

	if (ret < 0)

		goto error;

	SetPageUptodate(page);
@@ -595,7 +619,7 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page) 
	return 0;

 error:

	unlock_page(page);

	return -EIO;

	return ret;

}



static
@@ -608,12 +632,8 @@ void cache_page_release(nfs_readdir_descriptor_t *desc) 
static

struct page *get_cache_page(nfs_readdir_descriptor_t *desc)

{

	struct page *page;

	page = read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,

	return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,

			desc->page_index, (filler_t *)nfs_readdir_filler, desc);

	if (IS_ERR(page))

		desc->eof = 1;

	return page;

}



/*
@@ -639,8 +659,10 @@ int find_cache_page(nfs_readdir_descriptor_t *desc) 
static inline

int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)

{

	int res = -EAGAIN;

	int res;



	if (desc->page_index == 0)

		desc->current_index = 0;

	while (1) {

		res = find_cache_page(desc);

		if (res != -EAGAIN)
@@ -670,6 +692,8 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, 
	struct dentry *dentry = NULL;



	array = nfs_readdir_get_array(desc->page);

	if (IS_ERR(array))

		return PTR_ERR(array);



	for (i = desc->cache_entry_index; i < array->size; i++) {

		d_type = DT_UNKNOWN;
@@ -685,11 +709,9 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, 
			*desc->dir_cookie = array->array[i+1].cookie;

		else

			*desc->dir_cookie = array->last_cookie;

		if (i == array->eof_index) {

			desc->eof = 1;

			break;

		}

	}

	if (i == array->eof_index)

		desc->eof = 1;



	nfs_readdir_release_array(desc->page);

	cache_page_release(desc);