xfs: queue inactivation immediately when free realtime extents are tight

Now that we have made the inactivation of unlinked inodes a background
task to increase the throughput of file deletions, we need to be a
little more careful about how long of a delay we can tolerate.

Similar to the patch doing this for free space on the data device, if
the file being inactivated is a realtime file and the realtime volume is
running low on free extents, we want to run the worker ASAP so that the
realtime allocator can make better decisions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 60468a2..fbb18c2 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -147,7 +147,8 @@ typedef struct xfs_mount {
 	int			m_fixedfsid[2];	/* unchanged for life of FS */
 	uint			m_qflags;	/* quota status flags */
 	uint64_t		m_flags;	/* global mount flags */
-	int64_t			m_low_space[XFS_LOWSP_MAX];
+	uint64_t		m_low_space[XFS_LOWSP_MAX];
+	uint64_t		m_low_rtexts[XFS_LOWSP_MAX];
 	struct xfs_ino_geometry	m_ino_geo;	/* inode geometry */
 	struct xfs_trans_resv	m_resv;		/* precomputed res values */
 						/* low free space thresholds */