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 <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_discard.h b/fs/xfs/linux-2.6/xfs_discard.h
index e82b6dd..344879a 100644
--- a/fs/xfs/linux-2.6/xfs_discard.h
+++ b/fs/xfs/linux-2.6/xfs_discard.h
@@ -2,7 +2,9 @@
#define XFS_DISCARD_H 1
struct fstrim_range;
+struct list_head;
extern int xfs_ioc_trim(struct xfs_mount *, struct fstrim_range __user *);
+extern int xfs_discard_extents(struct xfs_mount *, struct list_head *);
#endif /* XFS_DISCARD_H */