This is a note to let you know that I've just added the patch titled fsnotify: replace inode pointer with an object id to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fsnotify-replace-inode-pointer-with-an-object-id.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3f96da8b1c76aa55994f98022967521b21fb1eb2 Author: Amir Goldstein <amir73il@xxxxxxxxx> Date: Thu Mar 19 17:10:15 2020 +0200 fsnotify: replace inode pointer with an object id [ Upstream commit dfc2d2594e4a79204a3967585245f00644b8f838 ] The event inode field is used only for comparison in queue merges and cannot be dereferenced after handle_event(), because it does not hold a refcount on the inode. Replace it with an abstract id to do the same thing. Link: https://lore.kernel.org/r/20200319151022.31456-8-amir73il@xxxxxxxxx Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 5778d1347b351..14d0ac4664595 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -26,7 +26,7 @@ static bool should_merge(struct fsnotify_event *old_fsn, old = FANOTIFY_E(old_fsn); new = FANOTIFY_E(new_fsn); - if (old_fsn->inode != new_fsn->inode || old->pid != new->pid || + if (old_fsn->objectid != new_fsn->objectid || old->pid != new->pid || old->fh_type != new->fh_type || old->fh_len != new->fh_len) return false; @@ -314,7 +314,7 @@ struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, if (!event) goto out; init: __maybe_unused - fsnotify_init_event(&event->fse, inode); + fsnotify_init_event(&event->fse, (unsigned long)inode); event->mask = mask; if (FAN_GROUP_FLAG(group, FAN_REPORT_TID)) event->pid = get_pid(task_pid(current)); diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index d510223d302ca..589dee9629938 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -39,7 +39,7 @@ static bool event_compare(struct fsnotify_event *old_fsn, if (old->mask & FS_IN_IGNORED) return false; if ((old->mask == new->mask) && - (old_fsn->inode == new_fsn->inode) && + (old_fsn->objectid == new_fsn->objectid) && (old->name_len == new->name_len) && (!old->name_len || !strcmp(old->name, new->name))) return true; @@ -118,7 +118,7 @@ int inotify_handle_event(struct fsnotify_group *group, mask &= ~IN_ISDIR; fsn_event = &event->fse; - fsnotify_init_event(fsn_event, inode); + fsnotify_init_event(fsn_event, (unsigned long)inode); event->mask = mask; event->wd = i_mark->wd; event->sync_cookie = cookie; diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index 107537a543fd8..81ffc8629fc4b 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -635,7 +635,7 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events) return ERR_PTR(-ENOMEM); } group->overflow_event = &oevent->fse; - fsnotify_init_event(group->overflow_event, NULL); + fsnotify_init_event(group->overflow_event, 0); oevent->mask = FS_Q_OVERFLOW; oevent->wd = -1; oevent->sync_cookie = 0; diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 1915bdba2fad9..64cfb5446f4d4 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -133,8 +133,7 @@ struct fsnotify_ops { */ struct fsnotify_event { struct list_head list; - /* inode may ONLY be dereferenced during handle_event(). */ - struct inode *inode; /* either the inode the event happened to or its parent */ + unsigned long objectid; /* identifier for queue merges */ }; /* @@ -500,10 +499,10 @@ 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, - struct inode *inode) + unsigned long objectid) { INIT_LIST_HEAD(&event->list); - event->inode = inode; + event->objectid = objectid; } #else