/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_FS_NOTIFY_H
#define _LINUX_FS_NOTIFY_H
/*
* include/linux/fsnotify.h - generic hooks for filesystem notification, to
* reduce in-source duplication from both dnotify and inotify.
*
* We don't compile any of this away in some complicated menagerie of ifdefs.
* Instead, we rely on the code inside to optimize away as needed.
*
* (C) Copyright 2005 Robert Love
*/
#include <linux/fsnotify_backend.h>
#include <linux/audit.h>
#include <linux/slab.h>
#include <linux/bug.h>
/*
* Notify this @dir inode about a change in the directory entry @dentry.
*
* Unlike fsnotify_parent(), the event will be reported regardless of the
* FS_EVENT_ON_CHILD mask on the parent inode.
*/
static inline int fsnotify_dirent(struct inode *dir, struct dentry *dentry,
__u32 mask)
{
return fsnotify(dir, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE,
&dentry->d_name, 0);
}
/* Notify this dentry's parent about a child's events. */
static inline int fsnotify_parent(const struct path *path,
struct dentry *dentry, __u32 mask)
{
if (!dentry)
dentry = path->dentry;
return __fsnotify_parent(path, dentry, mask);
}
/*
* Simple wrapper to consolidate calls fsnotify_parent()/fsnotify() when
* an event is on a path.
*/
static inline int fsnotify_path(struct inode *inode, const struct path *path,
__u32 mask)
{
int ret = fsnotify_parent(path, NULL, mask);
if (ret)
return ret;
return fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
}
/* Simple call site for access decisions */
static inline int fsnotify_perm(struct file *file, int mask)
{
int ret;
const struct path *path = &file->f_path;
struct inode *inode = file_inode(file);
__u32 fsnotify_mask = 0;
if (file->f_mode & FMODE_NONOTIFY)
return 0;
if (!(mask & (MAY_READ | MAY_OPEN)))
return 0;
if (mask & MAY_OPEN) {
fsnotify_mask = FS_OPEN_PERM;
if (file->f_flags & __FMODE_EXEC) {
ret = fsnotify_path(inode, path, FS_OPEN_EXEC_PERM);
if (ret)
return ret;
}
} else if (mask & MAY_READ) {
fsnotify_mask = FS_ACCESS_PERM;
}
if (S_ISDIR(inode->i_mode))
fsnotify_mask |= FS_ISDIR;
return fsnotify_path(inode, path, fsnotify_mask);
}
/*
* fsnotify_link_count - inode's link count changed
*/
static inline void fsnotify_link_count(struct inode *inode)
{
__u32 mask = FS_ATTRIB;
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
}
/*
* fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
*/
static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
const struct qstr *old_name,
int isdir, struct inode *target,
struct dentry *moved)
{
struct inode *source = moved->d_inode;
u32 fs_cookie = fsnotify_get_cookie();
__u32 old_dir_mask = FS_MOVED_FROM;
__u32 new_dir_mask = FS_MOVED_TO;
__u32 mask = FS_MOVE_SELF;
const struct qstr *new_name = &moved->d_name;
if (old_dir == new_dir)
old_dir_mask |= FS_DN_RENAME;
if (isdir) {
old_dir_mask |= FS_ISDIR;
new_dir_mask |= FS_ISDIR;
mask |= FS_ISDIR;
}
fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name,
fs_cookie);
fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name,
fs_cookie);
if (target)
fsnotify_link_count(target);
if (source)
fsnotify(source, mask, source, FSNOTIFY_EVENT_INODE, NULL, 0);
audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
}
/*
* fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
*/
static inline void fsnotify_inode_delete(struct inode *inode)
{
__fsnotify_inode_delete(inode);
}
/*
* fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
*/
static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
{
__fsnotify_vfsmount_delete(mnt);
}
/*
* fsnotify_inoderemove - an inode is going away
*/
static inline void fsnotify_inoderemove(struct inode *inode)
{
__u32 mask = FS_DELETE_SELF;
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
__fsnotify_inode_delete(inode);
}
/*
* fsnotify_create - 'name' was linked in
*/
static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
{
audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify_dirent(inode, dentry, FS_CREATE);
}
/*
* fsnotify_link - new hardlink in 'inode' directory
* Note: We have to pass also the linked inode ptr as some filesystems leave
* new_dentry->d_inode NULL and instantiate inode pointer later
*/
static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
{
fsnotify_link_count(inode);
audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, &new_dentry->d_name, 0);
}
/*
* fsnotify_unlink - 'name' was unlinked
*
* Caller must make sure that dentry->d_name is stable.
*/
static inline void fsnotify_unlink(struct inode *dir, struct dentry *dentry)
{
/* Expected to be called before d_delete() */
WARN_ON_ONCE(d_is_negative(dentry));
fsnotify_dirent(dir, dentry, FS_DELETE);
}
/*
* fsnotify_mkdir - directory 'name' was created
*/
static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
{
audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify_dirent(inode, dentry, FS_CREATE | FS_ISDIR);
}
/*
* fsnotify_rmdir - directory 'name' was removed
*
* Caller must make sure that dentry->d_name is stable.
*/
static inline void fsnotify_rmdir(struct inode *dir, struct dentry *dentry)
{
/* Expected to be called before d_delete() */
WARN_ON_ONCE(d_is_negative(dentry));
fsnotify_dirent(dir, dentry, FS_DELETE | FS_ISDIR);
}
/*
* fsnotify_access - file was read
*/
static inline void fsnotify_access(struct file *file)
{
const struct path *path = &file->f_path;
struct inode *inode = file_inode(file);
__u32 mask = FS_ACCESS;
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
if (!(file->f_mode & FMODE_NONOTIFY))
fsnotify_path(inode, path, mask);
}
/*
* fsnotify_modify - file was modified
*/
static inline void fsnotify_modify(struct file *file)
{
const struct path *path = &file->f_path;
struct inode *inode = file_inode(file);
__u32 mask = FS_MODIFY;
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
if (!(file->f_mode & FMODE_NONOTIFY))
fsnotify_path(inode, path, mask);
}
/*
* fsnotify_open - file was opened
*/
static inline void fsnotify_open(struct file *file)
{
const struct path *path = &file->f_path;
struct inode *inode = file_inode(file);
__u32 mask = FS_OPEN;
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
if (file->f_flags & __FMODE_EXEC)
mask |= FS_OPEN_EXEC;
fsnotify_path(inode, path, mask);
}
/*
* fsnotify_close - file was closed
*/
static inline void fsnotify_close(struct file *file)
{
const struct path *path = &file->f_path;
struct inode *inode = file_inode(file);
fmode_t mode = file->f_mode;
__u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
if (!(file->f_mode & FMODE_NONOTIFY))
fsnotify_path(inode, path, mask);
}
/*
* fsnotify_xattr - extended attributes were changed
*/
static inline void fsnotify_xattr(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
__u32 mask = FS_ATTRIB;
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
fsnotify_parent(NULL, dentry, mask);
fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
}
/*
* fsnotify_change - notify_change event. file was modified and/or metadata
* was changed.
*/
static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
{
struct inode *inode = dentry->d_inode;
__u32 mask = 0;
if (ia_valid & ATTR_UID)
mask |= FS_ATTRIB;
if (ia_valid & ATTR_GID)
mask |= FS_ATTRIB;
if (ia_valid & ATTR_SIZE)
mask |= FS_MODIFY;
/* both times implies a utime(s) call */
if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
mask |= FS_ATTRIB;
else if (ia_valid & ATTR_ATIME)
mask |= FS_ACCESS;
else if (ia_valid & ATTR_MTIME)
mask |= FS_MODIFY;
if (ia_valid & ATTR_MODE)
mask |= FS_ATTRIB;
if (mask) {
if (S_ISDIR(inode->i_mode))
mask |= FS_ISDIR;
fsnotify_parent(NULL, dentry, mask);
fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
}
}
#endif /* _LINUX_FS_NOTIFY_H */
