Re: [PATCH v3 09/15] fsnotify: Always run the merge hook
From: Amir Goldstein <amir73il@gmail.com>
Date: 2021-06-30 03:42:44
Also in:
linux-fsdevel
On Tue, Jun 29, 2021 at 10:12 PM Gabriel Krisman Bertazi [off-list ref] wrote:
FS_FAN_ERROR must be able to merge events even in the short window after they've been unqueued but prior to being read. Move the list_empty
This smells like trouble. Breaking abstractions like this should be done for a very good reason and I am not sure this is the case at hand. More on this on merge_error_event patch. Thanks, Amir.
quoted hunk ↗ jump to hunk
check into the merge hooks, such that merge() is always invoked if existing. Signed-off-by: Gabriel Krisman Bertazi <redacted> --- fs/notify/fanotify/fanotify.c | 3 ++- fs/notify/inotify/inotify_fsnotify.c | 3 +++ fs/notify/notification.c | 2 +- 3 files changed, 6 insertions(+), 2 deletions(-)diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index aba06b84da91..769703ef2b9a 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c@@ -168,7 +168,8 @@ static int fanotify_merge(struct fsnotify_group *group, * the event structure we have created in fanotify_handle_event() is the * one we should check for permission response. */ - if (fanotify_is_perm_event(new->mask)) + if (list_empty(&group->notification_list) || + fanotify_is_perm_event(new->mask)) return 0; hlist_for_each_entry(old, hlist, merge_list) {diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index a003a64ff8ee..2f357b4933c2 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c@@ -52,6 +52,9 @@ static int inotify_merge(struct fsnotify_group *group, struct list_head *list = &group->notification_list; struct fsnotify_event *last_event; + if (list_empty(list)) + return 0; + last_event = list_entry(list->prev, struct fsnotify_event, list); return event_compare(last_event, event); }diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 0d9ba592d725..1d06e0728a24 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c@@ -111,7 +111,7 @@ int fsnotify_add_event(struct fsnotify_group *group, goto queue; } - if (!list_empty(list) && merge) { + if (merge) { ret = merge(group, event); if (ret) { spin_unlock(&group->notification_lock); --2.32.0