在 2024/4/24 11:39, libao...@huaweicloud.com 写道:
From: Baokun Li <libaok...@huawei.com> Replacing wait_for_completion() with wait_for_completion_killable() in cachefiles_ondemand_send_req() allows us to kill processes that might trigger a hunk_task if the daemon is abnormal. But now only CACHEFILES_OP_READ is killable, because OP_CLOSE and OP_OPEN is initiated from kworker context and the signal is prohibited in these kworker. Note that when the req in xas changes, i.e. xas_load(&xas) != req, it means that a process will complete the current request soon, so wait again for the request to be completed. Suggested-by: Hou Tao <hout...@huawei.com> Signed-off-by: Baokun Li <libaok...@huawei.com>
Reviewed-by: Jia Zhu <zhujia...@bytedance.com>
--- fs/cachefiles/ondemand.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index 673e7ad52041..b766430f4abf 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -525,8 +525,25 @@ static int cachefiles_ondemand_send_req(struct cachefiles_object *object, goto out;wake_up_all(&cache->daemon_pollwq);- wait_for_completion(&req->done); - ret = req->error; +wait: + ret = wait_for_completion_killable(&req->done); + if (!ret) { + ret = req->error; + } else { + xas_reset(&xas); + xas_lock(&xas); + if (xas_load(&xas) == req) { + xas_store(&xas, NULL); + ret = -EINTR; + } + xas_unlock(&xas); + + /* Someone will complete it soon. */ + if (ret != -EINTR) { + cpu_relax(); + goto wait; + } + } cachefiles_req_put(req); return ret; out:
