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![Amir Goldstein](/assets/img/avatar_default.png)
Setting flags FAN_ONDIR FAN_EVENT_ON_CHILD in ignore mask has no effect. The FAN_EVENT_ON_CHILD flag in mask implicitly applies to ignore mask and ignore mask is always implicitly applied to events on directories. Define a mark flag that replaces this legacy behavior with logic of applying the ignore mask according to event flags in ignore mask. Implement the new logic to prepare for supporting an ignore mask that ignores events on children and ignore mask that does not ignore events on directories. To emphasize the change in terminology, also rename ignored_mask mark member to ignore_mask and use accessors to get only the effective ignored events or the ignored events and flags. This change in terminology finally aligns with the "ignore mask" language in man pages and in most of the comments. Link: https://lore.kernel.org/r/20220629144210.2983229-2-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
868 lines
29 KiB
C
868 lines
29 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Filesystem access notification for Linux
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*
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* Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
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*/
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#ifndef __LINUX_FSNOTIFY_BACKEND_H
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#define __LINUX_FSNOTIFY_BACKEND_H
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#ifdef __KERNEL__
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#include <linux/idr.h> /* inotify uses this */
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#include <linux/fs.h> /* struct inode */
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#include <linux/list.h>
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#include <linux/path.h> /* struct path */
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#include <linux/spinlock.h>
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#include <linux/types.h>
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#include <linux/atomic.h>
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#include <linux/user_namespace.h>
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#include <linux/refcount.h>
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#include <linux/mempool.h>
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#include <linux/sched/mm.h>
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/*
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* IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily
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* convert between them. dnotify only needs conversion at watch creation
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* so no perf loss there. fanotify isn't defined yet, so it can use the
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* wholes if it needs more events.
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*/
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#define FS_ACCESS 0x00000001 /* File was accessed */
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#define FS_MODIFY 0x00000002 /* File was modified */
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#define FS_ATTRIB 0x00000004 /* Metadata changed */
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#define FS_CLOSE_WRITE 0x00000008 /* Writtable file was closed */
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#define FS_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */
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#define FS_OPEN 0x00000020 /* File was opened */
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#define FS_MOVED_FROM 0x00000040 /* File was moved from X */
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#define FS_MOVED_TO 0x00000080 /* File was moved to Y */
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#define FS_CREATE 0x00000100 /* Subfile was created */
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#define FS_DELETE 0x00000200 /* Subfile was deleted */
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#define FS_DELETE_SELF 0x00000400 /* Self was deleted */
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#define FS_MOVE_SELF 0x00000800 /* Self was moved */
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#define FS_OPEN_EXEC 0x00001000 /* File was opened for exec */
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#define FS_UNMOUNT 0x00002000 /* inode on umount fs */
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#define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
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#define FS_ERROR 0x00008000 /* Filesystem Error (fanotify) */
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/*
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* FS_IN_IGNORED overloads FS_ERROR. It is only used internally by inotify
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* which does not support FS_ERROR.
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*/
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#define FS_IN_IGNORED 0x00008000 /* last inotify event here */
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#define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */
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#define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */
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#define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */
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/*
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* Set on inode mark that cares about things that happen to its children.
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* Always set for dnotify and inotify.
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* Set on inode/sb/mount marks that care about parent/name info.
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*/
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#define FS_EVENT_ON_CHILD 0x08000000
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#define FS_RENAME 0x10000000 /* File was renamed */
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#define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */
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#define FS_ISDIR 0x40000000 /* event occurred against dir */
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#define FS_MOVE (FS_MOVED_FROM | FS_MOVED_TO)
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/*
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* Directory entry modification events - reported only to directory
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* where entry is modified and not to a watching parent.
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* The watching parent may get an FS_ATTRIB|FS_EVENT_ON_CHILD event
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* when a directory entry inside a child subdir changes.
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*/
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#define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE | FS_RENAME)
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#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \
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FS_OPEN_EXEC_PERM)
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/*
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* This is a list of all events that may get sent to a parent that is watching
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* with flag FS_EVENT_ON_CHILD based on fs event on a child of that directory.
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*/
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#define FS_EVENTS_POSS_ON_CHILD (ALL_FSNOTIFY_PERM_EVENTS | \
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FS_ACCESS | FS_MODIFY | FS_ATTRIB | \
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FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | \
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FS_OPEN | FS_OPEN_EXEC)
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/*
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* This is a list of all events that may get sent with the parent inode as the
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* @to_tell argument of fsnotify().
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* It may include events that can be sent to an inode/sb/mount mark, but cannot
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* be sent to a parent watching children.
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*/
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#define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD)
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/* Events that can be reported to backends */
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#define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \
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FS_EVENTS_POSS_ON_CHILD | \
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FS_DELETE_SELF | FS_MOVE_SELF | \
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FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED | \
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FS_ERROR)
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/* Extra flags that may be reported with event or control handling of events */
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#define ALL_FSNOTIFY_FLAGS (FS_ISDIR | FS_EVENT_ON_CHILD | FS_DN_MULTISHOT)
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#define ALL_FSNOTIFY_BITS (ALL_FSNOTIFY_EVENTS | ALL_FSNOTIFY_FLAGS)
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struct fsnotify_group;
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struct fsnotify_event;
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struct fsnotify_mark;
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struct fsnotify_event_private_data;
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struct fsnotify_fname;
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struct fsnotify_iter_info;
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struct mem_cgroup;
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/*
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* Each group much define these ops. The fsnotify infrastructure will call
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* these operations for each relevant group.
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*
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* handle_event - main call for a group to handle an fs event
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* @group: group to notify
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* @mask: event type and flags
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* @data: object that event happened on
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* @data_type: type of object for fanotify_data_XXX() accessors
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* @dir: optional directory associated with event -
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* if @file_name is not NULL, this is the directory that
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* @file_name is relative to
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* @file_name: optional file name associated with event
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* @cookie: inotify rename cookie
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* @iter_info: array of marks from this group that are interested in the event
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*
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* handle_inode_event - simple variant of handle_event() for groups that only
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* have inode marks and don't have ignore mask
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* @mark: mark to notify
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* @mask: event type and flags
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* @inode: inode that event happened on
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* @dir: optional directory associated with event -
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* if @file_name is not NULL, this is the directory that
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* @file_name is relative to.
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* Either @inode or @dir must be non-NULL.
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* @file_name: optional file name associated with event
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* @cookie: inotify rename cookie
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*
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* free_group_priv - called when a group refcnt hits 0 to clean up the private union
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* freeing_mark - called when a mark is being destroyed for some reason. The group
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* MUST be holding a reference on each mark and that reference must be
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* dropped in this function. inotify uses this function to send
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* userspace messages that marks have been removed.
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*/
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struct fsnotify_ops {
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int (*handle_event)(struct fsnotify_group *group, u32 mask,
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const void *data, int data_type, struct inode *dir,
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const struct qstr *file_name, u32 cookie,
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struct fsnotify_iter_info *iter_info);
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int (*handle_inode_event)(struct fsnotify_mark *mark, u32 mask,
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struct inode *inode, struct inode *dir,
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const struct qstr *file_name, u32 cookie);
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void (*free_group_priv)(struct fsnotify_group *group);
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void (*freeing_mark)(struct fsnotify_mark *mark, struct fsnotify_group *group);
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void (*free_event)(struct fsnotify_group *group, struct fsnotify_event *event);
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/* called on final put+free to free memory */
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void (*free_mark)(struct fsnotify_mark *mark);
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};
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/*
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* all of the information about the original object we want to now send to
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* a group. If you want to carry more info from the accessing task to the
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* listener this structure is where you need to be adding fields.
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*/
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struct fsnotify_event {
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struct list_head list;
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};
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/*
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* A group is a "thing" that wants to receive notification about filesystem
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* events. The mask holds the subset of event types this group cares about.
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* refcnt on a group is up to the implementor and at any moment if it goes 0
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* everything will be cleaned up.
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*/
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struct fsnotify_group {
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const struct fsnotify_ops *ops; /* how this group handles things */
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/*
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* How the refcnt is used is up to each group. When the refcnt hits 0
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* fsnotify will clean up all of the resources associated with this group.
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* As an example, the dnotify group will always have a refcnt=1 and that
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* will never change. Inotify, on the other hand, has a group per
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* inotify_init() and the refcnt will hit 0 only when that fd has been
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* closed.
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*/
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refcount_t refcnt; /* things with interest in this group */
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/* needed to send notification to userspace */
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spinlock_t notification_lock; /* protect the notification_list */
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struct list_head notification_list; /* list of event_holder this group needs to send to userspace */
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wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */
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unsigned int q_len; /* events on the queue */
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unsigned int max_events; /* maximum events allowed on the list */
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/*
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* Valid fsnotify group priorities. Events are send in order from highest
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* priority to lowest priority. We default to the lowest priority.
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*/
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#define FS_PRIO_0 0 /* normal notifiers, no permissions */
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#define FS_PRIO_1 1 /* fanotify content based access control */
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#define FS_PRIO_2 2 /* fanotify pre-content access */
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unsigned int priority;
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bool shutdown; /* group is being shut down, don't queue more events */
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#define FSNOTIFY_GROUP_USER 0x01 /* user allocated group */
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#define FSNOTIFY_GROUP_DUPS 0x02 /* allow multiple marks per object */
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#define FSNOTIFY_GROUP_NOFS 0x04 /* group lock is not direct reclaim safe */
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int flags;
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unsigned int owner_flags; /* stored flags of mark_mutex owner */
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/* stores all fastpath marks assoc with this group so they can be cleaned on unregister */
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struct mutex mark_mutex; /* protect marks_list */
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atomic_t user_waits; /* Number of tasks waiting for user
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* response */
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struct list_head marks_list; /* all inode marks for this group */
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struct fasync_struct *fsn_fa; /* async notification */
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struct fsnotify_event *overflow_event; /* Event we queue when the
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* notification list is too
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* full */
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struct mem_cgroup *memcg; /* memcg to charge allocations */
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/* groups can define private fields here or use the void *private */
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union {
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void *private;
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#ifdef CONFIG_INOTIFY_USER
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struct inotify_group_private_data {
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spinlock_t idr_lock;
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struct idr idr;
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struct ucounts *ucounts;
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} inotify_data;
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#endif
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#ifdef CONFIG_FANOTIFY
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struct fanotify_group_private_data {
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/* Hash table of events for merge */
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struct hlist_head *merge_hash;
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/* allows a group to block waiting for a userspace response */
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struct list_head access_list;
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wait_queue_head_t access_waitq;
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int flags; /* flags from fanotify_init() */
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int f_flags; /* event_f_flags from fanotify_init() */
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struct ucounts *ucounts;
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mempool_t error_events_pool;
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} fanotify_data;
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#endif /* CONFIG_FANOTIFY */
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};
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};
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/*
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* These helpers are used to prevent deadlock when reclaiming inodes with
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* evictable marks of the same group that is allocating a new mark.
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*/
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static inline void fsnotify_group_lock(struct fsnotify_group *group)
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{
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mutex_lock(&group->mark_mutex);
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if (group->flags & FSNOTIFY_GROUP_NOFS)
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group->owner_flags = memalloc_nofs_save();
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}
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static inline void fsnotify_group_unlock(struct fsnotify_group *group)
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{
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if (group->flags & FSNOTIFY_GROUP_NOFS)
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memalloc_nofs_restore(group->owner_flags);
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mutex_unlock(&group->mark_mutex);
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}
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static inline void fsnotify_group_assert_locked(struct fsnotify_group *group)
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{
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WARN_ON_ONCE(!mutex_is_locked(&group->mark_mutex));
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if (group->flags & FSNOTIFY_GROUP_NOFS)
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WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
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}
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/* When calling fsnotify tell it if the data is a path or inode */
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enum fsnotify_data_type {
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FSNOTIFY_EVENT_NONE,
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FSNOTIFY_EVENT_PATH,
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FSNOTIFY_EVENT_INODE,
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FSNOTIFY_EVENT_DENTRY,
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FSNOTIFY_EVENT_ERROR,
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};
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struct fs_error_report {
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int error;
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struct inode *inode;
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struct super_block *sb;
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};
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static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
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{
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switch (data_type) {
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case FSNOTIFY_EVENT_INODE:
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return (struct inode *)data;
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case FSNOTIFY_EVENT_DENTRY:
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return d_inode(data);
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case FSNOTIFY_EVENT_PATH:
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return d_inode(((const struct path *)data)->dentry);
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case FSNOTIFY_EVENT_ERROR:
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return ((struct fs_error_report *)data)->inode;
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default:
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return NULL;
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}
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}
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static inline struct dentry *fsnotify_data_dentry(const void *data, int data_type)
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{
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switch (data_type) {
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case FSNOTIFY_EVENT_DENTRY:
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/* Non const is needed for dget() */
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return (struct dentry *)data;
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case FSNOTIFY_EVENT_PATH:
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return ((const struct path *)data)->dentry;
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default:
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return NULL;
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}
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}
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static inline const struct path *fsnotify_data_path(const void *data,
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int data_type)
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{
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switch (data_type) {
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case FSNOTIFY_EVENT_PATH:
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return data;
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default:
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return NULL;
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}
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}
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static inline struct super_block *fsnotify_data_sb(const void *data,
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int data_type)
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{
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switch (data_type) {
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case FSNOTIFY_EVENT_INODE:
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return ((struct inode *)data)->i_sb;
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case FSNOTIFY_EVENT_DENTRY:
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return ((struct dentry *)data)->d_sb;
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case FSNOTIFY_EVENT_PATH:
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return ((const struct path *)data)->dentry->d_sb;
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case FSNOTIFY_EVENT_ERROR:
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return ((struct fs_error_report *) data)->sb;
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default:
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return NULL;
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}
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}
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static inline struct fs_error_report *fsnotify_data_error_report(
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const void *data,
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int data_type)
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{
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switch (data_type) {
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case FSNOTIFY_EVENT_ERROR:
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return (struct fs_error_report *) data;
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default:
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return NULL;
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}
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}
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/*
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* Index to merged marks iterator array that correlates to a type of watch.
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* The type of watched object can be deduced from the iterator type, but not
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* the other way around, because an event can match different watched objects
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* of the same object type.
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* For example, both parent and child are watching an object of type inode.
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*/
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enum fsnotify_iter_type {
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FSNOTIFY_ITER_TYPE_INODE,
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FSNOTIFY_ITER_TYPE_VFSMOUNT,
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FSNOTIFY_ITER_TYPE_SB,
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FSNOTIFY_ITER_TYPE_PARENT,
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FSNOTIFY_ITER_TYPE_INODE2,
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FSNOTIFY_ITER_TYPE_COUNT
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};
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/* The type of object that a mark is attached to */
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enum fsnotify_obj_type {
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FSNOTIFY_OBJ_TYPE_ANY = -1,
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FSNOTIFY_OBJ_TYPE_INODE,
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FSNOTIFY_OBJ_TYPE_VFSMOUNT,
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FSNOTIFY_OBJ_TYPE_SB,
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FSNOTIFY_OBJ_TYPE_COUNT,
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FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT
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};
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static inline bool fsnotify_valid_obj_type(unsigned int obj_type)
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{
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return (obj_type < FSNOTIFY_OBJ_TYPE_COUNT);
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}
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struct fsnotify_iter_info {
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struct fsnotify_mark *marks[FSNOTIFY_ITER_TYPE_COUNT];
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struct fsnotify_group *current_group;
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unsigned int report_mask;
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int srcu_idx;
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};
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static inline bool fsnotify_iter_should_report_type(
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struct fsnotify_iter_info *iter_info, int iter_type)
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{
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return (iter_info->report_mask & (1U << iter_type));
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}
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static inline void fsnotify_iter_set_report_type(
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struct fsnotify_iter_info *iter_info, int iter_type)
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{
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iter_info->report_mask |= (1U << iter_type);
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}
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static inline struct fsnotify_mark *fsnotify_iter_mark(
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struct fsnotify_iter_info *iter_info, int iter_type)
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{
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if (fsnotify_iter_should_report_type(iter_info, iter_type))
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return iter_info->marks[iter_type];
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return NULL;
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}
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static inline int fsnotify_iter_step(struct fsnotify_iter_info *iter, int type,
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struct fsnotify_mark **markp)
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{
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while (type < FSNOTIFY_ITER_TYPE_COUNT) {
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*markp = fsnotify_iter_mark(iter, type);
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if (*markp)
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break;
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type++;
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}
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return type;
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}
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#define FSNOTIFY_ITER_FUNCS(name, NAME) \
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static inline struct fsnotify_mark *fsnotify_iter_##name##_mark( \
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struct fsnotify_iter_info *iter_info) \
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{ \
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return fsnotify_iter_mark(iter_info, FSNOTIFY_ITER_TYPE_##NAME); \
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}
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FSNOTIFY_ITER_FUNCS(inode, INODE)
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FSNOTIFY_ITER_FUNCS(parent, PARENT)
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FSNOTIFY_ITER_FUNCS(vfsmount, VFSMOUNT)
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FSNOTIFY_ITER_FUNCS(sb, SB)
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#define fsnotify_foreach_iter_type(type) \
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for (type = 0; type < FSNOTIFY_ITER_TYPE_COUNT; type++)
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#define fsnotify_foreach_iter_mark_type(iter, mark, type) \
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for (type = 0; \
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type = fsnotify_iter_step(iter, type, &mark), \
|
|
type < FSNOTIFY_ITER_TYPE_COUNT; \
|
|
type++)
|
|
|
|
/*
|
|
* fsnotify_connp_t is what we embed in objects which connector can be attached
|
|
* to. fsnotify_connp_t * is how we refer from connector back to object.
|
|
*/
|
|
struct fsnotify_mark_connector;
|
|
typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t;
|
|
|
|
/*
|
|
* Inode/vfsmount/sb point to this structure which tracks all marks attached to
|
|
* the inode/vfsmount/sb. The reference to inode/vfsmount/sb is held by this
|
|
* structure. We destroy this structure when there are no more marks attached
|
|
* to it. The structure is protected by fsnotify_mark_srcu.
|
|
*/
|
|
struct fsnotify_mark_connector {
|
|
spinlock_t lock;
|
|
unsigned short type; /* Type of object [lock] */
|
|
#define FSNOTIFY_CONN_FLAG_HAS_FSID 0x01
|
|
#define FSNOTIFY_CONN_FLAG_HAS_IREF 0x02
|
|
unsigned short flags; /* flags [lock] */
|
|
__kernel_fsid_t fsid; /* fsid of filesystem containing object */
|
|
union {
|
|
/* Object pointer [lock] */
|
|
fsnotify_connp_t *obj;
|
|
/* Used listing heads to free after srcu period expires */
|
|
struct fsnotify_mark_connector *destroy_next;
|
|
};
|
|
struct hlist_head list;
|
|
};
|
|
|
|
/*
|
|
* A mark is simply an object attached to an in core inode which allows an
|
|
* fsnotify listener to indicate they are either no longer interested in events
|
|
* of a type matching mask or only interested in those events.
|
|
*
|
|
* These are flushed when an inode is evicted from core and may be flushed
|
|
* when the inode is modified (as seen by fsnotify_access). Some fsnotify
|
|
* users (such as dnotify) will flush these when the open fd is closed and not
|
|
* at inode eviction or modification.
|
|
*
|
|
* Text in brackets is showing the lock(s) protecting modifications of a
|
|
* particular entry. obj_lock means either inode->i_lock or
|
|
* mnt->mnt_root->d_lock depending on the mark type.
|
|
*/
|
|
struct fsnotify_mark {
|
|
/* Mask this mark is for [mark->lock, group->mark_mutex] */
|
|
__u32 mask;
|
|
/* We hold one for presence in g_list. Also one ref for each 'thing'
|
|
* in kernel that found and may be using this mark. */
|
|
refcount_t refcnt;
|
|
/* Group this mark is for. Set on mark creation, stable until last ref
|
|
* is dropped */
|
|
struct fsnotify_group *group;
|
|
/* List of marks by group->marks_list. Also reused for queueing
|
|
* mark into destroy_list when it's waiting for the end of SRCU period
|
|
* before it can be freed. [group->mark_mutex] */
|
|
struct list_head g_list;
|
|
/* Protects inode / mnt pointers, flags, masks */
|
|
spinlock_t lock;
|
|
/* List of marks for inode / vfsmount [connector->lock, mark ref] */
|
|
struct hlist_node obj_list;
|
|
/* Head of list of marks for an object [mark ref] */
|
|
struct fsnotify_mark_connector *connector;
|
|
/* Events types and flags to ignore [mark->lock, group->mark_mutex] */
|
|
__u32 ignore_mask;
|
|
/* General fsnotify mark flags */
|
|
#define FSNOTIFY_MARK_FLAG_ALIVE 0x0001
|
|
#define FSNOTIFY_MARK_FLAG_ATTACHED 0x0002
|
|
/* inotify mark flags */
|
|
#define FSNOTIFY_MARK_FLAG_EXCL_UNLINK 0x0010
|
|
#define FSNOTIFY_MARK_FLAG_IN_ONESHOT 0x0020
|
|
/* fanotify mark flags */
|
|
#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x0100
|
|
#define FSNOTIFY_MARK_FLAG_NO_IREF 0x0200
|
|
#define FSNOTIFY_MARK_FLAG_HAS_IGNORE_FLAGS 0x0400
|
|
unsigned int flags; /* flags [mark->lock] */
|
|
};
|
|
|
|
#ifdef CONFIG_FSNOTIFY
|
|
|
|
/* called from the vfs helpers */
|
|
|
|
/* main fsnotify call to send events */
|
|
extern int fsnotify(__u32 mask, const void *data, int data_type,
|
|
struct inode *dir, const struct qstr *name,
|
|
struct inode *inode, u32 cookie);
|
|
extern int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data,
|
|
int data_type);
|
|
extern void __fsnotify_inode_delete(struct inode *inode);
|
|
extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt);
|
|
extern void fsnotify_sb_delete(struct super_block *sb);
|
|
extern u32 fsnotify_get_cookie(void);
|
|
|
|
static inline __u32 fsnotify_parent_needed_mask(__u32 mask)
|
|
{
|
|
/* FS_EVENT_ON_CHILD is set on marks that want parent/name info */
|
|
if (!(mask & FS_EVENT_ON_CHILD))
|
|
return 0;
|
|
/*
|
|
* This object might be watched by a mark that cares about parent/name
|
|
* info, does it care about the specific set of events that can be
|
|
* reported with parent/name info?
|
|
*/
|
|
return mask & FS_EVENTS_POSS_TO_PARENT;
|
|
}
|
|
|
|
static inline int fsnotify_inode_watches_children(struct inode *inode)
|
|
{
|
|
/* FS_EVENT_ON_CHILD is set if the inode may care */
|
|
if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD))
|
|
return 0;
|
|
/* this inode might care about child events, does it care about the
|
|
* specific set of events that can happen on a child? */
|
|
return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD;
|
|
}
|
|
|
|
/*
|
|
* Update the dentry with a flag indicating the interest of its parent to receive
|
|
* filesystem events when those events happens to this dentry->d_inode.
|
|
*/
|
|
static inline void fsnotify_update_flags(struct dentry *dentry)
|
|
{
|
|
assert_spin_locked(&dentry->d_lock);
|
|
|
|
/*
|
|
* Serialisation of setting PARENT_WATCHED on the dentries is provided
|
|
* by d_lock. If inotify_inode_watched changes after we have taken
|
|
* d_lock, the following __fsnotify_update_child_dentry_flags call will
|
|
* find our entry, so it will spin until we complete here, and update
|
|
* us with the new state.
|
|
*/
|
|
if (fsnotify_inode_watches_children(dentry->d_parent->d_inode))
|
|
dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
|
|
else
|
|
dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
|
|
}
|
|
|
|
/* called from fsnotify listeners, such as fanotify or dnotify */
|
|
|
|
/* create a new group */
|
|
extern struct fsnotify_group *fsnotify_alloc_group(
|
|
const struct fsnotify_ops *ops,
|
|
int flags);
|
|
/* get reference to a group */
|
|
extern void fsnotify_get_group(struct fsnotify_group *group);
|
|
/* drop reference on a group from fsnotify_alloc_group */
|
|
extern void fsnotify_put_group(struct fsnotify_group *group);
|
|
/* group destruction begins, stop queuing new events */
|
|
extern void fsnotify_group_stop_queueing(struct fsnotify_group *group);
|
|
/* destroy group */
|
|
extern void fsnotify_destroy_group(struct fsnotify_group *group);
|
|
/* fasync handler function */
|
|
extern int fsnotify_fasync(int fd, struct file *file, int on);
|
|
/* Free event from memory */
|
|
extern void fsnotify_destroy_event(struct fsnotify_group *group,
|
|
struct fsnotify_event *event);
|
|
/* attach the event to the group notification queue */
|
|
extern int fsnotify_insert_event(struct fsnotify_group *group,
|
|
struct fsnotify_event *event,
|
|
int (*merge)(struct fsnotify_group *,
|
|
struct fsnotify_event *),
|
|
void (*insert)(struct fsnotify_group *,
|
|
struct fsnotify_event *));
|
|
|
|
static inline int fsnotify_add_event(struct fsnotify_group *group,
|
|
struct fsnotify_event *event,
|
|
int (*merge)(struct fsnotify_group *,
|
|
struct fsnotify_event *))
|
|
{
|
|
return fsnotify_insert_event(group, event, merge, NULL);
|
|
}
|
|
|
|
/* Queue overflow event to a notification group */
|
|
static inline void fsnotify_queue_overflow(struct fsnotify_group *group)
|
|
{
|
|
fsnotify_add_event(group, group->overflow_event, NULL);
|
|
}
|
|
|
|
static inline bool fsnotify_is_overflow_event(u32 mask)
|
|
{
|
|
return mask & FS_Q_OVERFLOW;
|
|
}
|
|
|
|
static inline bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group)
|
|
{
|
|
assert_spin_locked(&group->notification_lock);
|
|
|
|
return list_empty(&group->notification_list);
|
|
}
|
|
|
|
extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group);
|
|
/* return, but do not dequeue the first event on the notification queue */
|
|
extern struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group);
|
|
/* return AND dequeue the first event on the notification queue */
|
|
extern struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group);
|
|
/* Remove event queued in the notification list */
|
|
extern void fsnotify_remove_queued_event(struct fsnotify_group *group,
|
|
struct fsnotify_event *event);
|
|
|
|
/* functions used to manipulate the marks attached to inodes */
|
|
|
|
/*
|
|
* Canonical "ignore mask" including event flags.
|
|
*
|
|
* Note the subtle semantic difference from the legacy ->ignored_mask.
|
|
* ->ignored_mask traditionally only meant which events should be ignored,
|
|
* while ->ignore_mask also includes flags regarding the type of objects on
|
|
* which events should be ignored.
|
|
*/
|
|
static inline __u32 fsnotify_ignore_mask(struct fsnotify_mark *mark)
|
|
{
|
|
__u32 ignore_mask = mark->ignore_mask;
|
|
|
|
/* The event flags in ignore mask take effect */
|
|
if (mark->flags & FSNOTIFY_MARK_FLAG_HAS_IGNORE_FLAGS)
|
|
return ignore_mask;
|
|
|
|
/*
|
|
* Legacy behavior:
|
|
* - Always ignore events on dir
|
|
* - Ignore events on child if parent is watching children
|
|
*/
|
|
ignore_mask |= FS_ISDIR;
|
|
ignore_mask &= ~FS_EVENT_ON_CHILD;
|
|
ignore_mask |= mark->mask & FS_EVENT_ON_CHILD;
|
|
|
|
return ignore_mask;
|
|
}
|
|
|
|
/* Legacy ignored_mask - only event types to ignore */
|
|
static inline __u32 fsnotify_ignored_events(struct fsnotify_mark *mark)
|
|
{
|
|
return mark->ignore_mask & ALL_FSNOTIFY_EVENTS;
|
|
}
|
|
|
|
/*
|
|
* Check if mask (or ignore mask) should be applied depending if victim is a
|
|
* directory and whether it is reported to a watching parent.
|
|
*/
|
|
static inline bool fsnotify_mask_applicable(__u32 mask, bool is_dir,
|
|
int iter_type)
|
|
{
|
|
/* Should mask be applied to a directory? */
|
|
if (is_dir && !(mask & FS_ISDIR))
|
|
return false;
|
|
|
|
/* Should mask be applied to a child? */
|
|
if (iter_type == FSNOTIFY_ITER_TYPE_PARENT &&
|
|
!(mask & FS_EVENT_ON_CHILD))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Effective ignore mask taking into account if event victim is a
|
|
* directory and whether it is reported to a watching parent.
|
|
*/
|
|
static inline __u32 fsnotify_effective_ignore_mask(struct fsnotify_mark *mark,
|
|
bool is_dir, int iter_type)
|
|
{
|
|
__u32 ignore_mask = fsnotify_ignored_events(mark);
|
|
|
|
if (!ignore_mask)
|
|
return 0;
|
|
|
|
/* For non-dir and non-child, no need to consult the event flags */
|
|
if (!is_dir && iter_type != FSNOTIFY_ITER_TYPE_PARENT)
|
|
return ignore_mask;
|
|
|
|
ignore_mask = fsnotify_ignore_mask(mark);
|
|
if (!fsnotify_mask_applicable(ignore_mask, is_dir, iter_type))
|
|
return 0;
|
|
|
|
return ignore_mask & ALL_FSNOTIFY_EVENTS;
|
|
}
|
|
|
|
/* Get mask for calculating object interest taking ignore mask into account */
|
|
static inline __u32 fsnotify_calc_mask(struct fsnotify_mark *mark)
|
|
{
|
|
__u32 mask = mark->mask;
|
|
|
|
if (!fsnotify_ignored_events(mark))
|
|
return mask;
|
|
|
|
/* Interest in FS_MODIFY may be needed for clearing ignore mask */
|
|
if (!(mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
|
|
mask |= FS_MODIFY;
|
|
|
|
/*
|
|
* If mark is interested in ignoring events on children, the object must
|
|
* show interest in those events for fsnotify_parent() to notice it.
|
|
*/
|
|
return mask | mark->ignore_mask;
|
|
}
|
|
|
|
/* Get mask of events for a list of marks */
|
|
extern __u32 fsnotify_conn_mask(struct fsnotify_mark_connector *conn);
|
|
/* Calculate mask of events for a list of marks */
|
|
extern void fsnotify_recalc_mask(struct fsnotify_mark_connector *conn);
|
|
extern void fsnotify_init_mark(struct fsnotify_mark *mark,
|
|
struct fsnotify_group *group);
|
|
/* Find mark belonging to given group in the list of marks */
|
|
extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp,
|
|
struct fsnotify_group *group);
|
|
/* Get cached fsid of filesystem containing object */
|
|
extern int fsnotify_get_conn_fsid(const struct fsnotify_mark_connector *conn,
|
|
__kernel_fsid_t *fsid);
|
|
/* attach the mark to the object */
|
|
extern int fsnotify_add_mark(struct fsnotify_mark *mark,
|
|
fsnotify_connp_t *connp, unsigned int obj_type,
|
|
int add_flags, __kernel_fsid_t *fsid);
|
|
extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
|
|
fsnotify_connp_t *connp,
|
|
unsigned int obj_type, int add_flags,
|
|
__kernel_fsid_t *fsid);
|
|
|
|
/* attach the mark to the inode */
|
|
static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
|
|
struct inode *inode,
|
|
int add_flags)
|
|
{
|
|
return fsnotify_add_mark(mark, &inode->i_fsnotify_marks,
|
|
FSNOTIFY_OBJ_TYPE_INODE, add_flags, NULL);
|
|
}
|
|
static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark,
|
|
struct inode *inode,
|
|
int add_flags)
|
|
{
|
|
return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks,
|
|
FSNOTIFY_OBJ_TYPE_INODE, add_flags,
|
|
NULL);
|
|
}
|
|
|
|
/* given a group and a mark, flag mark to be freed when all references are dropped */
|
|
extern void fsnotify_destroy_mark(struct fsnotify_mark *mark,
|
|
struct fsnotify_group *group);
|
|
/* detach mark from inode / mount list, group list, drop inode reference */
|
|
extern void fsnotify_detach_mark(struct fsnotify_mark *mark);
|
|
/* free mark */
|
|
extern void fsnotify_free_mark(struct fsnotify_mark *mark);
|
|
/* Wait until all marks queued for destruction are destroyed */
|
|
extern void fsnotify_wait_marks_destroyed(void);
|
|
/* Clear all of the marks of a group attached to a given object type */
|
|
extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group,
|
|
unsigned int obj_type);
|
|
/* run all the marks in a group, and clear all of the vfsmount marks */
|
|
static inline void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
|
|
{
|
|
fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_VFSMOUNT);
|
|
}
|
|
/* run all the marks in a group, and clear all of the inode marks */
|
|
static inline void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
|
|
{
|
|
fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_INODE);
|
|
}
|
|
/* run all the marks in a group, and clear all of the sn marks */
|
|
static inline void fsnotify_clear_sb_marks_by_group(struct fsnotify_group *group)
|
|
{
|
|
fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_SB);
|
|
}
|
|
extern void fsnotify_get_mark(struct fsnotify_mark *mark);
|
|
extern void fsnotify_put_mark(struct fsnotify_mark *mark);
|
|
extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info);
|
|
extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info);
|
|
|
|
static inline void fsnotify_init_event(struct fsnotify_event *event)
|
|
{
|
|
INIT_LIST_HEAD(&event->list);
|
|
}
|
|
|
|
#else
|
|
|
|
static inline int fsnotify(__u32 mask, const void *data, int data_type,
|
|
struct inode *dir, const struct qstr *name,
|
|
struct inode *inode, u32 cookie)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int __fsnotify_parent(struct dentry *dentry, __u32 mask,
|
|
const void *data, int data_type)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void __fsnotify_inode_delete(struct inode *inode)
|
|
{}
|
|
|
|
static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
|
|
{}
|
|
|
|
static inline void fsnotify_sb_delete(struct super_block *sb)
|
|
{}
|
|
|
|
static inline void fsnotify_update_flags(struct dentry *dentry)
|
|
{}
|
|
|
|
static inline u32 fsnotify_get_cookie(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void fsnotify_unmount_inodes(struct super_block *sb)
|
|
{}
|
|
|
|
#endif /* CONFIG_FSNOTIFY */
|
|
|
|
#endif /* __KERNEL __ */
|
|
|
|
#endif /* __LINUX_FSNOTIFY_BACKEND_H */
|