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_icache.c b/fs/xfs/xfs_icache.c
index 0bea604..0ca0b19 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1916,6 +1916,24 @@ xfs_inodegc_start(
 	xfs_inodegc_queue_all(mp);
 }
 
+#ifdef CONFIG_XFS_RT
+static inline bool
+xfs_inodegc_want_queue_rt_file(
+	struct xfs_inode	*ip)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	uint64_t		freertx;
+
+	if (!XFS_IS_REALTIME_INODE(ip))
+		return false;
+
+	freertx = READ_ONCE(mp->m_sb.sb_frextents);
+	return freertx < mp->m_low_rtexts[XFS_LOWSP_5_PCNT];
+}
+#else
+# define xfs_inodegc_want_queue_rt_file(ip)	(false)
+#endif /* CONFIG_XFS_RT */
+
 /*
  * Schedule the inactivation worker when:
  *
@@ -1938,6 +1956,9 @@ xfs_inodegc_want_queue_work(
 				XFS_FDBLOCKS_BATCH) < 0)
 		return true;
 
+	if (xfs_inodegc_want_queue_rt_file(ip))
+		return true;
+
 	if (xfs_inode_near_dquot_enforcement(ip, XFS_DQTYPE_USER))
 		return true;
 
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 5fe6f1d..ed1e7e3 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -365,13 +365,16 @@ void
 xfs_set_low_space_thresholds(
 	struct xfs_mount	*mp)
 {
-	int i;
+	uint64_t		dblocks = mp->m_sb.sb_dblocks;
+	uint64_t		rtexts = mp->m_sb.sb_rextents;
+	int			i;
+
+	do_div(dblocks, 100);
+	do_div(rtexts, 100);
 
 	for (i = 0; i < XFS_LOWSP_MAX; i++) {
-		uint64_t space = mp->m_sb.sb_dblocks;
-
-		do_div(space, 100);
-		mp->m_low_space[i] = space * (i + 1);
+		mp->m_low_space[i] = dblocks * (i + 1);
+		mp->m_low_rtexts[i] = rtexts * (i + 1);
 	}
 }
 
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 */