linux/fs/tracefs/internal.h
Steven Rostedt (Google) 407c6726ca eventfs: Use simple_recursive_removal() to clean up dentries
Looking at how dentry is removed via the tracefs system, I found that
eventfs does not do everything that it did under tracefs. The tracefs
removal of a dentry calls simple_recursive_removal() that does a lot more
than a simple d_invalidate().

As it should be a requirement that any eventfs_inode that has a dentry, so
does its parent. When removing a eventfs_inode, if it has a dentry, a call
to simple_recursive_removal() on that dentry should clean up all the
dentries underneath it.

Add WARN_ON_ONCE() to check for the parent having a dentry if any children
do.

Link: https://lore.kernel.org/all/20231101022553.GE1957730@ZenIV/
Link: https://lkml.kernel.org/r/20231101172650.552471568@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 5bdcd5f533 ("eventfs: Implement removal of meta data from eventfs")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-11-02 00:18:36 -04:00

83 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _TRACEFS_INTERNAL_H
#define _TRACEFS_INTERNAL_H
enum {
TRACEFS_EVENT_INODE = BIT(1),
TRACEFS_EVENT_TOP_INODE = BIT(2),
};
struct tracefs_inode {
unsigned long flags;
void *private;
struct inode vfs_inode;
};
/*
* struct eventfs_attr - cache the mode and ownership of a eventfs entry
* @mode: saved mode plus flags of what is saved
* @uid: saved uid if changed
* @gid: saved gid if changed
*/
struct eventfs_attr {
int mode;
kuid_t uid;
kgid_t gid;
};
/*
* struct eventfs_inode - hold the properties of the eventfs directories.
* @list: link list into the parent directory
* @entries: the array of entries representing the files in the directory
* @name: the name of the directory to create
* @children: link list into the child eventfs_inode
* @dentry: the dentry of the directory
* @d_parent: pointer to the parent's dentry
* @d_children: The array of dentries to represent the files when created
* @entry_attrs: Saved mode and ownership of the @d_children
* @attr: Saved mode and ownership of eventfs_inode itself
* @data: The private data to pass to the callbacks
* @is_freed: Flag set if the eventfs is on its way to be freed
* Note if is_freed is set, then dentry is corrupted.
* @nr_entries: The number of items in @entries
*/
struct eventfs_inode {
struct list_head list;
const struct eventfs_entry *entries;
const char *name;
struct list_head children;
struct dentry *dentry; /* Check is_freed to access */
struct dentry *d_parent;
struct dentry **d_children;
struct eventfs_attr *entry_attrs;
struct eventfs_attr attr;
void *data;
/*
* Union - used for deletion
* @llist: for calling dput() if needed after RCU
* @rcu: eventfs_inode to delete in RCU
*/
union {
struct llist_node llist;
struct rcu_head rcu;
};
unsigned int is_freed:1;
unsigned int nr_entries:31;
};
static inline struct tracefs_inode *get_tracefs(const struct inode *inode)
{
return container_of(inode, struct tracefs_inode, vfs_inode);
}
struct dentry *tracefs_start_creating(const char *name, struct dentry *parent);
struct dentry *tracefs_end_creating(struct dentry *dentry);
struct dentry *tracefs_failed_creating(struct dentry *dentry);
struct inode *tracefs_get_inode(struct super_block *sb);
struct dentry *eventfs_start_creating(const char *name, struct dentry *parent);
struct dentry *eventfs_failed_creating(struct dentry *dentry);
struct dentry *eventfs_end_creating(struct dentry *dentry);
void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry);
#endif /* _TRACEFS_INTERNAL_H */