From dfc2d2594e4a79204a3967585245f00644b8f838 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 19 Mar 2020 17:10:15 +0200 Subject: [PATCH] fsnotify: replace inode pointer with an object id 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@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara --- fs/notify/fanotify/fanotify.c | 4 ++-- fs/notify/inotify/inotify_fsnotify.c | 4 ++-- fs/notify/inotify/inotify_user.c | 2 +- include/linux/fsnotify_backend.h | 7 +++---- 4 files changed, 8 insertions(+), 9 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 19ec7a4f4d50..6a202aaf941f 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; @@ -312,7 +312,7 @@ 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 6bb98522bbfd..2ebc89047153 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; @@ -116,7 +116,7 @@ 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 107537a543fd..81ffc8629fc4 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 337c87cf34d6..c72cbea20ef7 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -132,8 +132,7 @@ 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 */ }; /* @@ -526,10 +525,10 @@ 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