xfs: implement busy extent tracking for rtgroups

For rtgroups filesystems, track newly freed (rt) space through the log
until the rt EFIs have been committed to disk.  This way we ensure that
space cannot be reused until all traces of the old owner are gone.

As a fringe benefit, we now support -o discard on the realtime device.

Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>

1 files changed, 11 insertions, 1 deletions

diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index 30220bf8c3f4..4ddfb7e395b3 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -24,6 +24,7 @@
 #include "xfs_errortag.h"
 #include "xfs_log.h"
 #include "xfs_buf_item.h"
+#include "xfs_extent_busy.h"
 
 /*
  * Realtime allocator bitmap functions shared with userspace.
@@ -1120,6 +1121,7 @@ xfs_rtfree_blocks(
 {
 	struct xfs_mount	*mp = tp->t_mountp;
 	xfs_extlen_t		mod;
+	int			error;
 
 	ASSERT(rtlen <= XFS_MAX_BMBT_EXTLEN);
 
@@ -1135,8 +1137,16 @@ xfs_rtfree_blocks(
 		return -EIO;
 	}
 
-	return xfs_rtfree_extent(tp, rtg, xfs_rtb_to_rtx(mp, rtbno),
+	error = xfs_rtfree_extent(tp, rtg, xfs_rtb_to_rtx(mp, rtbno),
 			xfs_extlen_to_rtxlen(mp, rtlen));
+	if (error)
+		return error;
+
+	if (xfs_has_rtgroups(mp))
+		xfs_extent_busy_insert(tp, rtg_group(rtg),
+				xfs_rtb_to_rgbno(mp, rtbno), rtlen, 0);
+
+	return 0;
 }
 
 /* Find all the free records within a given range. */