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AFS: Don't put struct file on the stack

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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>
This commit is contained in:
Al Viro 2010-05-21 15:27:09 +01:00 committed by Al Viro
parent 4403158ba2
commit f6d335c08d
4 changed files with 41 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
fs/afs/dir.c
View File

@ -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))

64
fs/afs/file.c
View File

@ -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;

1
fs/afs/internal.h
View File

@ -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

6
fs/afs/mntpt.c
View File

@ -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;