On 10/15/20 4:11 AM, Pavel Begunkov wrote: > On 15/10/2020 09:53, Nathan Chancellor wrote: >> On Wed, Oct 14, 2020 at 08:44:22PM +0100, Pavel Begunkov wrote: >>> - io_put_req_deferred(link, 2); >>> + >>> + /* >>> + * It's ok to free under spinlock as they're not linked anymore, >>> + * but avoid REQ_F_WORK_INITIALIZED because it may deadlock on >>> + * work.fs->lock. >>> + */ >>> + if (link->flags | REQ_F_WORK_INITIALIZED) >>> + io_put_req_deferred(link, 2); >>> + else >>> + io_double_put_req(link); >> >> fs/io_uring.c:1816:19: warning: bitwise or with non-zero value always >> evaluates to true [-Wtautological-bitwise-compare] >> if (link->flags | REQ_F_WORK_INITIALIZED) >> ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ >> 1 warning generated. >> >> According to the comment, was it intended for that to be a bitwise AND >> then negated to check for the absence of it? If so, wouldn't it be >> clearer to flip the condition so that a negation is not necessary like >> below? I can send a formal patch if my analysis is correct but if not, >> feel free to fix it yourself and add > > I have no idea what have happened, but yeah, there should be "&", > though without any additional negation. That's because deferred > version is safer. > > Nathan, thanks for letting know! > Jens, could you please fold in the change below. Done. -- Jens Axboe
