From b4e4e1407312ae5a267ed7d716e6d4e7120a8430 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 17 Dec 2009 21:24:21 -0500 Subject: [PATCH] fsnotify: clone existing events fsnotify_clone_event will take an event, clone it, and return the cloned event to the caller. Since events may be in use by multiple fsnotify groups simultaneously certain event entries (such as the mask) cannot be changed after the event was created. Since fanotify would like to merge events happening on the same file it needs a new clean event to work with so it can change any fields it wishes. Signed-off-by: Eric Paris --- fs/notify/notification.c | 29 +++++++++++++++++++++++++---- include/linux/fsnotify_backend.h | 3 +++ 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 6dc96b35e4a..bc9470c7ece 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -284,11 +284,33 @@ static void initialize_event(struct fsnotify_event *event) spin_lock_init(&event->lock); - event->data_type = FSNOTIFY_EVENT_NONE; - INIT_LIST_HEAD(&event->private_data_list); } +struct fsnotify_event *fsnotify_clone_event(struct fsnotify_event *old_event) +{ + struct fsnotify_event *event; + + event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL); + if (!event) + return NULL; + + memcpy(event, old_event, sizeof(*event)); + initialize_event(event); + + if (event->name_len) { + event->file_name = kstrdup(old_event->file_name, GFP_KERNEL); + if (!event->file_name) { + kmem_cache_free(fsnotify_event_cachep, event); + return NULL; + } + } + if (event->data_type == FSNOTIFY_EVENT_PATH) + path_get(&event->path); + + return event; +} + /* * fsnotify_create_event - Allocate a new event which will be sent to each * group's handle_event function if the group was interested in this @@ -324,6 +346,7 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, event->sync_cookie = cookie; event->to_tell = to_tell; + event->data_type = data_type; switch (data_type) { case FSNOTIFY_EVENT_FILE: { @@ -340,12 +363,10 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, event->path.dentry = path->dentry; event->path.mnt = path->mnt; path_get(&event->path); - event->data_type = FSNOTIFY_EVENT_PATH; break; } case FSNOTIFY_EVENT_INODE: event->inode = data; - event->data_type = FSNOTIFY_EVENT_INODE; break; case FSNOTIFY_EVENT_NONE: event->inode = NULL; diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 25789d45fad..3a7fff23553 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -363,6 +363,9 @@ extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 void *data, int data_is, const char *name, u32 cookie, gfp_t gfp); +/* fanotify likes to change events after they are on lists... */ +extern struct fsnotify_event *fsnotify_clone_event(struct fsnotify_event *old_event); + #else static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, -- 2.20.1