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| author | Jan Kara <jack@suse.cz> | 2019-05-01 18:05:11 +0200 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2019-05-01 18:05:11 +0200 |
| commit | 11a6f8e2db26519b6468686411deafab81c14741 (patch) | |
| tree | 0739bb2a32546805eb2e2665f17f384aec85cf14 /fs/notify | |
| parent | b1da6a51871c6929dced1a7fad81990988b36ed6 (diff) | |
| download | lwn-11a6f8e2db26519b6468686411deafab81c14741.tar.gz lwn-11a6f8e2db26519b6468686411deafab81c14741.zip | |
fsnotify: Clarify connector assignment in fsnotify_add_mark_list()
Add a comment explaining why WRITE_ONCE() is enough when setting
mark->connector which can get dereferenced by RCU protected readers.
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/mark.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 22acb0a79b53..b251105f646f 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -619,6 +619,11 @@ restart: /* mark should be the last entry. last is the current last entry */ hlist_add_behind_rcu(&mark->obj_list, &last->obj_list); added: + /* + * Since connector is attached to object using cmpxchg() we are + * guaranteed that connector initialization is fully visible by anyone + * seeing mark->connector set. + */ WRITE_ONCE(mark->connector, conn); out_err: spin_unlock(&conn->lock); |