On Mon, Oct 07, 2019 at 04:17:36PM -0400, Dennis Zhou wrote: > When discard is enabled, everytime a pinned extent is released back to > the block_group's free space cache, a discard is issued for the extent. > This is an overeager approach when it comes to discarding and helping > the SSD maintain enough free space to prevent severe garbage collection > situations. > > This adds the beginning of async discard. Instead of issuing a discard > prior to returning it to the free space, it is just marked as untrimmed. > The block_group is then added to a LRU which then feeds into a workqueue > to issue discards at a much slower rate. Full discarding of unused block > groups is still done and will be address in a future patch in this > series. > > For now, we don't persist the discard state of extents and bitmaps. > Therefore, our failure recovery mode will be to consider extents > untrimmed. This lets us handle failure and unmounting as one in the > same. > > Signed-off-by: Dennis Zhou <[email protected]>
Reviewed-by: Josef Bacik <[email protected]> Thanks, Josef
