[LU-13900] don't call aio_complete() in lustre upon errors

• Type: Bug
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.14.0
• Severity: 3
• Assignee: Wang Shilong (Inactive)
• Reporter: Wang Shilong (Inactive)

Description

See following codes in aio_ret():

    static inline ssize_t aio_ret(struct kiocb *req, ssize_t ret)
    {
            switch (ret) {
            case -EIOCBQUEUED:
                    return ret;
            case -ERESTARTSYS:
            case -ERESTARTNOINTR:
            case -ERESTARTNOHAND:
            case -ERESTART_RESTARTBLOCK:
                    /*
                     * There's no easy way to restart the
                     * syscall since other AIO's may be already running.
                     * Just fail this IO with EINTR.
                     */
                    ret = -EINTR;
                    /*FALLTHRU*/
            default:
                    aio_complete(req, ret, 0);
                    return 0;
            }
    }
   

VFS will call aio_complete() if ret is not -EIOCBQUEUED,
this could happen when we don't pass user buffer as page
alignment or some other errors happen in Lustre.

So in Lustre, we need be careful to handle this case to avoid double
aio_complete() called.

Issue Links

• is related to: LU-4198 Improve IO performance when using DIRECT IO using libaio