On 3/15/25 11:01 AM, Kent Overstreet wrote: > On Sat, Mar 15, 2025 at 10:47:09AM -0600, Jens Axboe wrote: >> On 3/11/25 2:15 PM, Kent Overstreet wrote: >>> REQ_FUA|REQ_READ means "do a read that bypasses the controller cache", >>> the same as writes. >>> >>> This is useful for when the filesystem gets a checksum error, it's >>> possible that a bit was flipped in the controller cache, and when we >>> retry we want to retry the entire IO, not just from cache. >>> >>> The nvme driver already passes through REQ_FUA for reads, not just >>> writes, so disabling the warning is sufficient to start using it, and >>> bcachefs is implementing additional retries for checksum errors so can >>> immediately use it. >> >> This one got effectively nak'ed by various folks here: >> >>> Link: https://lore.kernel.org/linux-block/20250311133517.3095878-1-kent.overstreet@xxxxxxxxx/ >> >> yet it's part of this series and in linux-next? Hmm? > > As I explained in that thread, they were only thinking about the caching > of writes. > > That's not what we're concerned about; when we retry a read due to a > checksum error we do not want the previous _read_ cached. Please follow the usual procedure of getting the patch acked/reviewed on the block list, and go through the usual trees. Until that happens, this patch should not be in your tree, not should it be staged in linux-next. -- Jens Axboe
