#ifdef __KERNEL__
+#include <linux/idr.h> /* inotify uses this */
#include <linux/fs.h> /* struct inode */
#include <linux/list.h>
#include <linux/path.h> /* struct path */
#define FS_DN_RENAME 0x10000000 /* file renamed */
#define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */
+/* This inode cares about things that happen to its children. Always set for
+ * dnotify and inotify. */
+#define FS_EVENT_ON_CHILD 0x08000000
+
+/* This is a list of all events that may get sent to a parernt based on fs event
+ * happening to inodes inside that directory */
+#define FS_EVENTS_POSS_ON_CHILD (FS_ACCESS | FS_MODIFY | FS_ATTRIB |\
+ FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN |\
+ FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE |\
+ FS_DELETE)
+
+/* listeners that hard code group numbers near the top */
+#define DNOTIFY_GROUP_NUM UINT_MAX
+#define INOTIFY_GROUP_NUM (DNOTIFY_GROUP_NUM-1)
+
struct fsnotify_group;
struct fsnotify_event;
+struct fsnotify_mark_entry;
+struct fsnotify_event_private_data;
/*
* Each group much define these ops. The fsnotify infrastructure will call
* these operations for each relevant group.
*
+ * should_send_event - given a group, inode, and mask this function determines
+ * if the group is interested in this event.
* handle_event - main call for a group to handle an fs event
* free_group_priv - called when a group refcnt hits 0 to clean up the private union
+ * freeing-mark - this means that a mark has been flagged to die when everything
+ * finishes using it. The function is supplied with what must be a
+ * valid group and inode to use to clean up.
*/
struct fsnotify_ops {
+ bool (*should_send_event)(struct fsnotify_group *group, struct inode *inode, __u32 mask);
int (*handle_event)(struct fsnotify_group *group, struct fsnotify_event *event);
void (*free_group_priv)(struct fsnotify_group *group);
+ void (*freeing_mark)(struct fsnotify_mark_entry *entry, struct fsnotify_group *group);
+ void (*free_event_priv)(struct fsnotify_event_private_data *priv);
};
/*
const struct fsnotify_ops *ops; /* how this group handles things */
- /* prevents double list_del of group_list. protected by global fsnotify_gr_mutex */
+ /* needed to send notification to userspace */
+ struct mutex notification_mutex; /* protect the notification_list */
+ struct list_head notification_list; /* list of event_holder this group needs to send to userspace */
+ wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */
+ unsigned int q_len; /* events on the queue */
+ unsigned int max_events; /* maximum events allowed on the list */
+
+ /* stores all fastapth entries assoc with this group so they can be cleaned on unregister */
+ spinlock_t mark_lock; /* protect mark_entries list */
+ atomic_t num_marks; /* 1 for each mark entry and 1 for not being
+ * past the point of no return when freeing
+ * a group */
+ struct list_head mark_entries; /* all inode mark entries for this group */
+
+ /* prevents double list_del of group_list. protected by global fsnotify_grp_mutex */
bool on_group_list;
/* groups can define private fields here or use the void *private */
union {
void *private;
+#ifdef CONFIG_INOTIFY_USER
+ struct inotify_group_private_data {
+ spinlock_t idr_lock;
+ struct idr idr;
+ u32 last_wd;
+ struct fasync_struct *fa; /* async notification */
+ struct user_struct *user;
+ } inotify_data;
+#endif
};
};
/*
+ * A single event can be queued in multiple group->notification_lists.
+ *
+ * each group->notification_list will point to an event_holder which in turns points
+ * to the actual event that needs to be sent to userspace.
+ *
+ * Seemed cheaper to create a refcnt'd event and a small holder for every group
+ * than create a different event for every group
+ *
+ */
+struct fsnotify_event_holder {
+ struct fsnotify_event *event;
+ struct list_head event_list;
+};
+
+/*
+ * Inotify needs to tack data onto an event. This struct lets us later find the
+ * correct private data of the correct group.
+ */
+struct fsnotify_event_private_data {
+ struct fsnotify_group *group;
+ struct list_head event_list;
+};
+
+/*
* all of the information about the original object we want to now send to
* a group. If you want to carry more info from the accessing task to the
* listener this structure is where you need to be adding fields.
*/
struct fsnotify_event {
+ /*
+ * If we create an event we are also likely going to need a holder
+ * to link to a group. So embed one holder in the event. Means only
+ * one allocation for the common case where we only have one group
+ */
+ struct fsnotify_event_holder holder;
spinlock_t lock; /* protection for the associated event_holder and private_list */
/* to_tell may ONLY be dereferenced during handle_event(). */
struct inode *to_tell; /* either the inode the event happened to or its parent */
int data_type; /* which of the above union we have */
atomic_t refcnt; /* how many groups still are using/need to send this event */
__u32 mask; /* the type of access, bitwise OR for FS_* event types */
+
+ u32 sync_cookie; /* used to corrolate events, namely inotify mv events */
+ char *file_name;
+ size_t name_len;
+
+ struct list_head private_data_list; /* groups can store private data here */
+};
+
+/*
+ * a mark is simply an entry 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.
+ */
+struct fsnotify_mark_entry {
+ __u32 mask; /* mask this mark entry is for */
+ /* we hold ref for each i_list and g_list. also one ref for each 'thing'
+ * in kernel that found and may be using this mark. */
+ atomic_t refcnt; /* active things looking at this mark */
+ struct inode *inode; /* inode this entry is associated with */
+ struct fsnotify_group *group; /* group this mark entry is for */
+ struct hlist_node i_list; /* list of mark_entries by inode->i_fsnotify_mark_entries */
+ struct list_head g_list; /* list of mark_entries by group->i_fsnotify_mark_entries */
+ spinlock_t lock; /* protect group, inode, and killme */
+ struct list_head free_i_list; /* tmp list used when freeing this mark */
+ struct list_head free_g_list; /* tmp list used when freeing this mark */
+ void (*free_mark)(struct fsnotify_mark_entry *entry); /* called on final put+free */
};
#ifdef CONFIG_FSNOTIFY
/* called from the vfs helpers */
/* main fsnotify call to send events */
-extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is);
+extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
+ const char *name, u32 cookie);
+extern void __fsnotify_parent(struct dentry *dentry, __u32 mask);
+extern void __fsnotify_inode_delete(struct inode *inode);
+extern u32 fsnotify_get_cookie(void);
+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_dcache_flags(struct dentry *dentry)
+{
+ struct dentry *parent;
+
+ assert_spin_locked(&dcache_lock);
+ assert_spin_locked(&dentry->d_lock);
+
+ parent = dentry->d_parent;
+ if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode))
+ dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
+ else
+ dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
+}
+
+/*
+ * fsnotify_d_instantiate - instantiate a dentry for inode
+ * Called with dcache_lock held.
+ */
+static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
+{
+ if (!inode)
+ return;
+
+ assert_spin_locked(&dcache_lock);
+
+ spin_lock(&dentry->d_lock);
+ __fsnotify_update_dcache_flags(dentry);
+ spin_unlock(&dentry->d_lock);
+}
/* called from fsnotify listeners, such as fanotify or dnotify */
extern struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num,
__u32 mask,
const struct fsnotify_ops *ops);
+/* run all marks associated with this group and update group->mask */
+extern void fsnotify_recalc_group_mask(struct fsnotify_group *group);
/* drop reference on a group from fsnotify_obtain_group */
extern void fsnotify_put_group(struct fsnotify_group *group);
/* take a reference to an event */
extern void fsnotify_get_event(struct fsnotify_event *event);
extern void fsnotify_put_event(struct fsnotify_event *event);
-/* find private data previously attached to an event */
-extern struct fsnotify_event_private_data *fsnotify_get_priv_from_event(struct fsnotify_group *group,
- struct fsnotify_event *event);
+/* find private data previously attached to an event and unlink it */
+extern struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnotify_group *group,
+ struct fsnotify_event *event);
+
+/* attach the event to the group notification queue */
+extern int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event,
+ struct fsnotify_event_private_data *priv);
+/* true if the group notification queue is empty */
+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_notify_event(struct fsnotify_group *group);
+/* return AND dequeue the first event on the notification queue */
+extern struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group);
+
+/* functions used to manipulate the marks attached to inodes */
+
+/* run all marks associated with an inode and update inode->i_fsnotify_mask */
+extern void fsnotify_recalc_inode_mask(struct inode *inode);
+extern void fsnotify_init_mark(struct fsnotify_mark_entry *entry, void (*free_mark)(struct fsnotify_mark_entry *entry));
+/* find (and take a reference) to a mark associated with group and inode */
+extern struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *group, struct inode *inode);
+/* attach the mark to both the group and the inode */
+extern int fsnotify_add_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group, struct inode *inode);
+/* given a mark, flag it to be freed when all references are dropped */
+extern void fsnotify_destroy_mark_by_entry(struct fsnotify_mark_entry *entry);
+/* run all the marks in a group, and flag them to be freed */
+extern void fsnotify_clear_marks_by_group(struct fsnotify_group *group);
+extern void fsnotify_get_mark(struct fsnotify_mark_entry *entry);
+extern void fsnotify_put_mark(struct fsnotify_mark_entry *entry);
+extern void fsnotify_unmount_inodes(struct list_head *list);
/* put here because inotify does some weird stuff when destroying watches */
extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
- void *data, int data_is);
+ void *data, int data_is, const char *name,
+ u32 cookie, gfp_t gfp);
+
#else
-static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is)
+static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
+ const char *name, u32 cookie)
{}
+
+static inline void __fsnotify_parent(struct dentry *dentry, __u32 mask)
+{}
+
+static inline void __fsnotify_inode_delete(struct inode *inode)
+{}
+
+static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
+{}
+
+static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
+{}
+
+static inline u32 fsnotify_get_cookie(void)
+{
+ return 0;
+}
+
+static inline void fsnotify_unmount_inodes(struct list_head *list)
+{}
+
#endif /* CONFIG_FSNOTIFY */
#endif /* __KERNEL __ */
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