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Commit f6d335c0 authored by Al Viro's avatar Al Viro Committed by Al Viro
Browse files

AFS: Don't put struct file on the stack 



Don't put struct file on the stack as it takes up quite a lot of space
and violates lifetime rules for struct file.

Rather than calling afs_readpage() indirectly from the directory routines by
way of read_mapping_page(), split afs_readpage() to have afs_page_filler()
that's given a key instead of a file and call read_cache_page(), specifying the
new function directly.  Use it in afs_readpages() as well.

Also make use of this in afs_mntpt_check_symlink() too for the same reason.

Reported-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent 4403158b

fs/afs/dir.c

+1 −5
Original line number Diff line number Diff line
@@ -189,13 +189,9 @@ static struct page *afs_dir_get_page(struct inode *dir, unsigned long index, 
				     struct key *key)

{

	struct page *page;

	struct file file = {

		.private_data = key,

	};



	_enter("{%lu},%lu", dir->i_ino, index);



	page = read_mapping_page(dir->i_mapping, index, &file);

	page = read_cache_page(dir->i_mapping, index, afs_page_filler, key);

	if (!IS_ERR(page)) {

		kmap(page);

		if (!PageChecked(page))

fs/afs/file.c

+37 −27
Original line number Diff line number Diff line
@@ -121,34 +121,19 @@ static void afs_file_readpage_read_complete(struct page *page, 
#endif



/*

 * AFS read page from file, directory or symlink

 * read page from file, directory or symlink, given a key to use

 */

static int afs_readpage(struct file *file, struct page *page)

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

{

	struct afs_vnode *vnode;

	struct inode *inode;

	struct key *key;

	struct inode *inode = page->mapping->host;

	struct afs_vnode *vnode = AFS_FS_I(inode);

	struct key *key = data;

	size_t len;

	off_t offset;

	int ret;



	inode = page->mapping->host;



	if (file) {

		key = file->private_data;

		ASSERT(key != NULL);

	} else {

		key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell);

		if (IS_ERR(key)) {

			ret = PTR_ERR(key);

			goto error_nokey;

		}

	}



	_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);



	vnode = AFS_FS_I(inode);



	BUG_ON(!PageLocked(page));



	ret = -ESTALE;
@@ -214,31 +199,56 @@ static int afs_readpage(struct file *file, struct page *page) 
		unlock_page(page);

	}



	if (!file)

		key_put(key);

	_leave(" = 0");

	return 0;



error:

	SetPageError(page);

	unlock_page(page);

	if (!file)

		key_put(key);

error_nokey:

	_leave(" = %d", ret);

	return ret;

}



/*

 * read page from file, directory or symlink, given a file to nominate the key

 * to be used

 */

static int afs_readpage(struct file *file, struct page *page)

{

	struct key *key;

	int ret;



	if (file) {

		key = file->private_data;

		ASSERT(key != NULL);

		ret = afs_page_filler(key, page);

	} else {

		struct inode *inode = page->mapping->host;

		key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell);

		if (IS_ERR(key)) {

			ret = PTR_ERR(key);

		} else {

			ret = afs_page_filler(key, page);

			key_put(key);

		}

	}

	return ret;

}



/*

 * read a set of pages

 */

static int afs_readpages(struct file *file, struct address_space *mapping,

			 struct list_head *pages, unsigned nr_pages)

{

	struct key *key = file->private_data;

	struct afs_vnode *vnode;

	int ret = 0;



	_enter(",{%lu},,%d", mapping->host->i_ino, nr_pages);

	_enter("{%d},{%lu},,%d",

	       key_serial(key), mapping->host->i_ino, nr_pages);



	ASSERT(key != NULL);



	vnode = AFS_FS_I(mapping->host);

	if (vnode->flags & AFS_VNODE_DELETED) {
@@ -279,7 +289,7 @@ static int afs_readpages(struct file *file, struct address_space *mapping, 
	}



	/* load the missing pages from the network */

	ret = read_cache_pages(mapping, pages, (void *) afs_readpage, file);

	ret = read_cache_pages(mapping, pages, afs_page_filler, key);



	_leave(" = %d [netting]", ret);

	return ret;

fs/afs/internal.h

+1 −0
Original line number Diff line number Diff line
@@ -494,6 +494,7 @@ extern const struct file_operations afs_file_operations; 


extern int afs_open(struct inode *, struct file *);

extern int afs_release(struct inode *, struct file *);

extern int afs_page_filler(void *, struct page *);



/*

 * flock.c

fs/afs/mntpt.c

+2 −4
Original line number Diff line number Diff line
@@ -49,9 +49,6 @@ static unsigned long afs_mntpt_expiry_timeout = 10 * 60; 
 */

int afs_mntpt_check_symlink(struct afs_vnode *vnode, struct key *key)

{

	struct file file = {

		.private_data = key,

	};

	struct page *page;

	size_t size;

	char *buf;
@@ -61,7 +58,8 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode, struct key *key) 
	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);



	/* read the contents of the symlink into the pagecache */

	page = read_mapping_page(AFS_VNODE_TO_I(vnode)->i_mapping, 0, &file);

	page = read_cache_page(AFS_VNODE_TO_I(vnode)->i_mapping, 0,

			       afs_page_filler, key);

	if (IS_ERR(page)) {

		ret = PTR_ERR(page);

		goto out;