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From:   Gabriel Krisman Bertazi <krisman@collabora.com>
To:     amir73il@gmail.com
Cc:     kernel@collabora.com, djwong@kernel.org, tytso@mit.edu,
        david@fromorbit.com, jack@suse.com, dhowells@redhat.com,
        khazhy@google.com, linux-fsdevel@vger.kernel.org,
        linux-ext4@vger.kernel.org,
        Gabriel Krisman Bertazi <krisman@collabora.com>
Subject: [PATCH v2 01/14] fsnotify: Don't call insert hook for overflow events
Date:   Tue, 15 Jun 2021 19:55:43 -0400
Message-Id: <20210615235556.970928-2-krisman@collabora.com>
In-Reply-To: <20210615235556.970928-1-krisman@collabora.com>
References: <20210615235556.970928-1-krisman@collabora.com>
MIME-Version: 1.0
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Overflow events are not mergeable, so they are not hashed_events.  But,
when failing inside fsnotify_add_event, for lack of space,
fsnotify_add_event() still calls the insert hook, which adds the
overflow event to the merge list.

Avoid calling the insert hook when adding an overflow event.

Fixes: 94e00d28a680 ("fsnotify: use hash table for faster events merge")
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 fs/notify/notification.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 32f45543b9c6..033294669e07 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -106,6 +106,11 @@ int fsnotify_add_event(struct fsnotify_group *group,
 			return ret;
 		}
 		event = group->overflow_event;
+		/*
+		 * Since overflow events are not mergeable, don't insert
+		 * them in the merge hash.
+		 */
+		insert = NULL;
 		goto queue;
 	}
 
-- 
2.31.0