linux_dsm_epyc7002/fs/notify/fsnotify.h
Jan Kara abc77577a6 fsnotify: Provide framework for dropping SRCU lock in ->handle_event
fanotify wants to drop fsnotify_mark_srcu lock when waiting for response
from userspace so that the whole notification subsystem is not blocked
during that time. This patch provides a framework for safely getting
mark reference for a mark found in the object list which pins the mark
in that list. We can then drop fsnotify_mark_srcu, wait for userspace
response and then safely continue iteration of the object list once we
reaquire fsnotify_mark_srcu.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:36 +02:00

59 lines
2.1 KiB
C

#ifndef __FS_NOTIFY_FSNOTIFY_H_
#define __FS_NOTIFY_FSNOTIFY_H_
#include <linux/list.h>
#include <linux/fsnotify.h>
#include <linux/srcu.h>
#include <linux/types.h>
#include "../mount.h"
struct fsnotify_iter_info {
struct fsnotify_mark *inode_mark;
struct fsnotify_mark *vfsmount_mark;
int srcu_idx;
};
/* destroy all events sitting in this groups notification queue */
extern void fsnotify_flush_notify(struct fsnotify_group *group);
/* protects reads of inode and vfsmount marks list */
extern struct srcu_struct fsnotify_mark_srcu;
/* compare two groups for sorting of marks lists */
extern int fsnotify_compare_groups(struct fsnotify_group *a,
struct fsnotify_group *b);
/* Find mark belonging to given group in the list of marks */
extern struct fsnotify_mark *fsnotify_find_mark(
struct fsnotify_mark_connector __rcu **connp,
struct fsnotify_group *group);
/* Destroy all marks connected via given connector */
extern void fsnotify_destroy_marks(struct fsnotify_mark_connector __rcu **connp);
/* run the list of all marks associated with inode and destroy them */
static inline void fsnotify_clear_marks_by_inode(struct inode *inode)
{
fsnotify_destroy_marks(&inode->i_fsnotify_marks);
}
/* run the list of all marks associated with vfsmount and destroy them */
static inline void fsnotify_clear_marks_by_mount(struct vfsmount *mnt)
{
fsnotify_destroy_marks(&real_mount(mnt)->mnt_fsnotify_marks);
}
/* prepare for freeing all marks associated with given group */
extern void fsnotify_detach_group_marks(struct fsnotify_group *group);
/* Wait until all marks queued for destruction are destroyed */
extern void fsnotify_wait_marks_destroyed(void);
/*
* update the dentry->d_flags of all of inode's children to indicate if inode cares
* about events that happen to its children.
*/
extern void __fsnotify_update_child_dentry_flags(struct inode *inode);
/* allocate and destroy and event holder to attach events to notification/access queues */
extern struct fsnotify_event_holder *fsnotify_alloc_event_holder(void);
extern void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder);
#endif /* __FS_NOTIFY_FSNOTIFY_H_ */