linux/fs/notify/fsnotify.h
Eric Paris 90b1e7a578 fsnotify: allow marks to not pin inodes in core
inotify marks must pin inodes in core.  dnotify doesn't technically need to
since they are closed when the directory is closed.  fanotify also need to
pin inodes in core as it works today.  But the next step is to introduce
the concept of 'ignored masks' which is actually a mask of events for an
inode of no interest.  I claim that these should be liberally sent to the
kernel and should not pin the inode in core.  If the inode is brought back
in the listener will get an event it may have thought excluded, but this is
not a serious situation and one any listener should deal with.

This patch lays the ground work for non-pinning inode marks by using lazy
inode pinning.  We do not pin a mark until it has a non-zero mask entry.  If a
listener new sets a mask we never pin the inode.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 09:58:59 -04:00

60 lines
2.6 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>
/* protects reads of fsnotify_groups */
extern struct srcu_struct fsnotify_grp_srcu;
/* all groups which receive inode fsnotify events */
extern struct list_head fsnotify_inode_groups;
/* all groups which receive vfsmount fsnotify events */
extern struct list_head fsnotify_vfsmount_groups;
/* all bitwise OR of all event types (FS_*) for all fsnotify_inode_groups */
extern __u32 fsnotify_inode_mask;
/* all bitwise OR of all event types (FS_*) for all fsnotify_vfsmount_groups */
extern __u32 fsnotify_vfsmount_mask;
/* destroy all events sitting in this groups notification queue */
extern void fsnotify_flush_notify(struct fsnotify_group *group);
extern void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *fsn_mark,
__u32 mask);
/* add a mark to an inode */
extern int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
struct fsnotify_group *group, struct inode *inode,
int allow_dups);
/* add a mark to a vfsmount */
extern int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
struct fsnotify_group *group, struct vfsmount *mnt,
int allow_dups);
/* add a group to the inode group list */
extern void fsnotify_add_inode_group(struct fsnotify_group *group);
/* add a group to the vfsmount group list */
extern void fsnotify_add_vfsmount_group(struct fsnotify_group *group);
/* final kfree of a group */
extern void fsnotify_final_destroy_group(struct fsnotify_group *group);
/* vfsmount specific destruction of a mark */
extern void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark);
/* inode specific destruction of a mark */
extern void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark);
/* run the list of all marks associated with inode and flag them to be freed */
extern void fsnotify_clear_marks_by_inode(struct inode *inode);
/* run the list of all marks associated with vfsmount and flag them to be freed */
extern void fsnotify_clear_marks_by_mount(struct vfsmount *mnt);
/*
* 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_ */