In the Linux kernel, the following vulnerability has been resolved: md/raid1,raid10: don't ignore IO flags If blk-wbt is enabled by default, it's found that raid write performance is quite bad because all IO are throttled by wbt of underlying disks, due to flag REQIDLE is ignored. And turns out this behaviour exist since blk-wbt is introduced. Other than REQIDLE, other flags should not be ignored as well, for example REQMETA can be set for filesystems, clearing it can cause priority reverse problems; And REQNOWAIT should not be cleared as well, because io will wait instead of failing directly in underlying disks. Fix those problems by keep IO flags from master bio. Fises: f51d46d0e7cb ("md: add support for REQ_NOWAIT")