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: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index adc1cb7..b42d5cc 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -189,13 +189,9 @@
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))
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 0df9bc2..14d89fa 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -121,34 +121,19 @@
#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 @@
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 @@
}
/* 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;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index a10f258..807f284 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -494,6 +494,7 @@
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
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index b3feddc..a9e2303 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -49,9 +49,6 @@
*/
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 @@
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;