[PATCH 3.12 76/83] take anon inode allocation to libfs.c

Greg Kroah-Hartman
2013-12-06T22:24:10Z

From: Al Viro <viro@zeniv.linux.org.uk>

commit 6987843ff7e836ea65b554905aec34d2fad05c94 upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/anon_inodes.c | 50 ++------------------------------------------------
fs/libfs.c | 43 +++++++++++++++++++++++++++++++++++++++++++
include/linux/fs.h | 1 +
3 files changed, 46 insertions(+), 48 deletions(-)

--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -24,7 +24,6 @@

static struct vfsmount *anon_inode_mnt __read_mostly;
static struct inode *anon_inode_inode;
-static const struct file_operations anon_inode_fops;

/*
* anon_inodefs_dname() is called from d_path().
@@ -39,51 +38,6 @@ static const struct dentry_operations an
.d_dname = anon_inodefs_dname,
};

-/*
- * nop .set_page_dirty method so that people can use .page_mkwrite on
- * anon inodes.
- */
-static int anon_set_page_dirty(struct page *page)
-{
- return 0;
-};
-
-static const struct address_space_operations anon_aops = {
- .set_page_dirty = anon_set_page_dirty,
-};
-
-/*
- * A single inode exists for all anon_inode files. Contrary to pipes,
- * anon_inode inodes have no associated per-instance data, so we need
- * only allocate one of them.
- */
-static struct inode *anon_inode_mkinode(struct super_block *s)
-{
- struct inode *inode = new_inode_pseudo(s);
-
- if (!inode)
- return ERR_PTR(-ENOMEM);
-
- inode->i_ino = get_next_ino();
- inode->i_fop = &anon_inode_fops;
-
- inode->i_mapping->a_ops = &anon_aops;
-
- /*
- * Mark the inode dirty from the very beginning,
- * that way it will never be moved to the dirty
- * list because mark_inode_dirty() will think
- * that it already _is_ on the dirty list.
- */
- inode->i_state = I_DIRTY;
- inode->i_mode = S_IRUSR | S_IWUSR;
- inode->i_uid = current_fsuid();
- inode->i_gid = current_fsgid();
- inode->i_flags |= S_PRIVATE;
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
- return inode;
-}
-
static struct dentry *anon_inodefs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
@@ -92,7 +46,7 @@ static struct dentry *anon_inodefs_mount
&anon_inodefs_dentry_operations, ANON_INODE_FS_MAGIC);
if (!IS_ERR(root)) {
struct super_block *s = root->d_sb;
- anon_inode_inode = anon_inode_mkinode(s);
+ anon_inode_inode = alloc_anon_inode(s);
if (IS_ERR(anon_inode_inode)) {
dput(root);
deactivate_locked_super(s);
@@ -134,7 +88,7 @@ struct file *anon_inode_getfile_private(
if (fops->owner && !try_module_get(fops->owner))
return ERR_PTR(-ENOENT);

- inode = anon_inode_mkinode(anon_inode_mnt->mnt_sb);
+ inode = alloc_anon_inode(anon_inode_mnt->mnt_sb);
if (IS_ERR(inode)) {
file = ERR_PTR(-ENOMEM);
goto err_module;
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -993,3 +993,46 @@ EXPORT_SYMBOL_GPL(simple_attr_open);
EXPORT_SYMBOL_GPL(simple_attr_release);
EXPORT_SYMBOL_GPL(simple_attr_read);
EXPORT_SYMBOL_GPL(simple_attr_write);
+
+/*
+ * nop .set_page_dirty method so that people can use .page_mkwrite on
+ * anon inodes.
+ */
+static int anon_set_page_dirty(struct page *page)
+{
+ return 0;
+};
+
+/*
+ * A single inode exists for all anon_inode files. Contrary to pipes,
+ * anon_inode inodes have no associated per-instance data, so we need
+ * only allocate one of them.
+ */
+struct inode *alloc_anon_inode(struct super_block *s)
+{
+ static const struct address_space_operations anon_aops = {
+ .set_page_dirty = anon_set_page_dirty,
+ };
+ struct inode *inode = new_inode_pseudo(s);
+
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ inode->i_ino = get_next_ino();
+ inode->i_mapping->a_ops = &anon_aops;
+
+ /*
+ * Mark the inode dirty from the very beginning,
+ * that way it will never be moved to the dirty
+ * list because mark_inode_dirty() will think
+ * that it already _is_ on the dirty list.
+ */
+ inode->i_state = I_DIRTY;
+ inode->i_mode = S_IRUSR | S_IWUSR;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
+ inode->i_flags |= S_PRIVATE;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ return inode;
+}
+EXPORT_SYMBOL(alloc_anon_inode);
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2562,6 +2562,7 @@ extern int simple_write_begin(struct fil
extern int simple_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
+extern struct inode *alloc_anon_inode(struct super_block *);

extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);