From e84661aa84e2e003738563f65155d4f12dc474e7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 20 May 2011 13:45:32 +0000 Subject: xfs: add online discard support Now that we have reliably tracking of deleted extents in a transaction we can easily implement "online" discard support which calls blkdev_issue_discard once a transaction commits. The actual discard is a two stage operation as we first have to mark the busy extent as not available for reuse before we can start the actual discard. Note that we don't bother supporting discard for the non-delaylog mode. Signed-off-by: Christoph Hellwig Signed-off-by: Alex Elder --- Documentation/filesystems/xfs.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt index 7bff3e4..3fc0c31 100644 --- a/Documentation/filesystems/xfs.txt +++ b/Documentation/filesystems/xfs.txt @@ -39,6 +39,12 @@ When mounting an XFS filesystem, the following options are accepted. drive level write caching to be enabled, for devices that support write barriers. + discard + Issue command to let the block device reclaim space freed by the + filesystem. This is useful for SSD devices, thinly provisioned + LUNs and virtual machine images, but may have a performance + impact. This option is incompatible with the nodelaylog option. + dmapi Enable the DMAPI (Data Management API) event callouts. Use with the "mtpt" option. -- cgit v1.1