xfs: add background scanning to clear eofblocks inodes
Create a new mount workqueue and delayed_work to enable background
scanning and freeing of eofblocks inodes. The scanner kicks in once
speculative preallocation occurs and stops requeueing itself when
no eofblocks inodes exist.
The scan interval is based on the new
'speculative_prealloc_lifetime' tunable (default to 5m). The
background scanner performs unfiltered, best effort scans (which
skips inodes under lock contention or with a dirty cache mapping).
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 906e6dc..96e344e 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -615,6 +615,32 @@
return last_error;
}
+/*
+ * Background scanning to trim post-EOF preallocated space. This is queued
+ * based on the 'background_prealloc_discard_period' tunable (5m by default).
+ */
+STATIC void
+xfs_queue_eofblocks(
+ struct xfs_mount *mp)
+{
+ rcu_read_lock();
+ if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_EOFBLOCKS_TAG))
+ queue_delayed_work(mp->m_eofblocks_workqueue,
+ &mp->m_eofblocks_work,
+ msecs_to_jiffies(xfs_eofb_secs * 1000));
+ rcu_read_unlock();
+}
+
+void
+xfs_eofblocks_worker(
+ struct work_struct *work)
+{
+ struct xfs_mount *mp = container_of(to_delayed_work(work),
+ struct xfs_mount, m_eofblocks_work);
+ xfs_icache_free_eofblocks(mp, NULL);
+ xfs_queue_eofblocks(mp);
+}
+
int
xfs_inode_ag_iterator(
struct xfs_mount *mp,
@@ -1273,6 +1299,9 @@
XFS_ICI_EOFBLOCKS_TAG);
spin_unlock(&ip->i_mount->m_perag_lock);
+ /* kick off background trimming */
+ xfs_queue_eofblocks(ip->i_mount);
+
trace_xfs_perag_set_eofblocks(ip->i_mount, pag->pag_agno,
-1, _RET_IP_);
}