[RFC 12/20] securityfs: Pass static variables as parameters from top level functions

Stefan Berger
2021-11-30T16:08:41Z

Pass the securityfs_-prefixed static variables from current top level
functions so that new APIs allow callers to pass in similar parameters and
thus share most of the existing functions.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
security/inode.c | 95 +++++++++++++++++++++++++++++++-----------------
1 file changed, 61 insertions(+), 34 deletions(-)

diff --git a/security/inode.c b/security/inode.c
index e523829c22cb..429744ff4ab3 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -88,6 +88,11 @@ static struct file_system_type securityfs_type = {
* this file.
* @iops: a point to a struct of inode_operations that should be used for
* this file/dir
+ * @mount: a pointer to a pointer for existing vfsmount to use or for
+ * one to create
+ * @mount_count: pointer to integer for mount_count that goes along with
+ * @mount
+ *
*
* This is the basic "create a file/dir/symlink" function for
* securityfs. It allows for a wide range of flexibility in creating
@@ -107,7 +112,9 @@ static struct file_system_type securityfs_type = {
static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops,
- const struct inode_operations *iops)
+ const struct inode_operations *iops,
+ struct file_system_type *fs_type,
+ struct vfsmount **mount, int *mount_count)
{
struct dentry *dentry;
struct inode *dir, *inode;
@@ -118,12 +125,12 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,

pr_debug("securityfs: creating file '%s'\n",name);

- error = simple_pin_fs(&securityfs_type, &securityfs_mount, &securityfs_mount_count);
+ error = simple_pin_fs(fs_type, mount, mount_count);
if (error)
return ERR_PTR(error);

if (!parent)
- parent = securityfs_mount->mnt_root;
+ parent = (*mount)->mnt_root;

dir = d_inode(parent);

@@ -168,7 +175,7 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
dentry = ERR_PTR(error);
out:
inode_unlock(dir);
- simple_release_fs(&securityfs_mount, &securityfs_mount_count);
+ simple_release_fs(mount, mount_count);
return dentry;
}

@@ -201,7 +208,9 @@ struct dentry *securityfs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
- return securityfs_create_dentry(name, mode, parent, data, fops, NULL);
+ return securityfs_create_dentry(name, mode, parent, data, fops, NULL,
+ &securityfs_type, &securityfs_mount,
+ &securityfs_mount_count);
}
EXPORT_SYMBOL_GPL(securityfs_create_file);

@@ -231,6 +240,29 @@ struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
}
EXPORT_SYMBOL_GPL(securityfs_create_dir);

+struct dentry *_securityfs_create_symlink(const char *name,
+ struct dentry *parent,
+ const char *target,
+ const struct inode_operations *iops,
+ struct file_system_type *fs_type,
+ struct vfsmount **mount, int *mount_count)
+{
+ struct dentry *dent;
+ char *link = NULL;
+
+ if (target) {
+ link = kstrdup(target, GFP_KERNEL);
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ }
+ dent = securityfs_create_dentry(name, S_IFLNK | 0444, parent,
+ link, NULL, iops, fs_type,
+ mount, mount_count);
+ if (IS_ERR(dent))
+ kfree(link);
+
+ return dent;
+}
/**
* securityfs_create_symlink - create a symlink in the securityfs filesystem
*
@@ -262,37 +294,13 @@ struct dentry *securityfs_create_symlink(const char *name,
const char *target,
const struct inode_operations *iops)
{
- struct dentry *dent;
- char *link = NULL;
-
- if (target) {
- link = kstrdup(target, GFP_KERNEL);
- if (!link)
- return ERR_PTR(-ENOMEM);
- }
- dent = securityfs_create_dentry(name, S_IFLNK | 0444, parent,
- link, NULL, iops);
- if (IS_ERR(dent))
- kfree(link);
-
- return dent;
+ return _securityfs_create_symlink(name, parent, target, iops,
+ &securityfs_type, &securityfs_mount,
+ &securityfs_mount_count);
}
EXPORT_SYMBOL_GPL(securityfs_create_symlink);

-/**
- * securityfs_remove - removes a file or directory from the securityfs filesystem
- *
- * @dentry: a pointer to a the dentry of the file or directory to be removed.
- *
- * This function removes a file or directory in securityfs that was previously
- * created with a call to another securityfs function (like
- * securityfs_create_file() or variants thereof.)
- *
- * This function is required to be called in order for the file to be
- * removed. No automatic cleanup of files will happen when a module is
- * removed; you are responsible here.
- */
-void securityfs_remove(struct dentry *dentry)
+void _securityfs_remove(struct dentry *dentry, struct vfsmount **mount, int *mount_count)
{
struct inode *dir;

@@ -309,8 +317,27 @@ void securityfs_remove(struct dentry *dentry)
dput(dentry);
}
inode_unlock(dir);
- simple_release_fs(&securityfs_mount, &securityfs_mount_count);
+ simple_release_fs(mount, mount_count);
+}
+
+/**
+ * securityfs_remove - removes a file or directory from the securityfs filesystem
+ *
+ * @dentry: a pointer to a the dentry of the file or directory to be removed.
+ *
+ * This function removes a file or directory in securityfs that was previously
+ * created with a call to another securityfs function (like
+ * securityfs_create_file() or variants thereof.)
+ *
+ * This function is required to be called in order for the file to be
+ * removed. No automatic cleanup of files will happen when a module is
+ * removed; you are responsible here.
+ */
+void securityfs_remove(struct dentry *dentry)
+{
+ _securityfs_remove(dentry, &securityfs_mount, &securityfs_mount_count);
}
+
EXPORT_SYMBOL_GPL(securityfs_remove);

#ifdef CONFIG_SECURITY
--
2.31.1