f2fs: add f2fs_destroy_trace_ios to free radix tree

This patch removes radix tree after finishing tracing IOs.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/fs/f2fs/trace.c b/fs/f2fs/trace.c
index 92fa38a47e63..b3570dcca945 100644
--- a/fs/f2fs/trace.c
+++ b/fs/f2fs/trace.c
@@ -11,6 +11,7 @@
 #include <linux/fs.h>
 #include <linux/f2fs_fs.h>
 #include <linux/sched.h>
+#include <linux/radix-tree.h>
 
 #include "f2fs.h"
 #include "trace.h"
@@ -120,3 +121,39 @@ void f2fs_build_trace_ios(void)
 {
 	spin_lock_init(&pids_lock);
 }
+
+#define PIDVEC_SIZE	128
+static unsigned int gang_lookup_pids(pid_t *results, unsigned long first_index,
+							unsigned int max_items)
+{
+	struct radix_tree_iter iter;
+	void **slot;
+	unsigned int ret = 0;
+
+	if (unlikely(!max_items))
+		return 0;
+
+	radix_tree_for_each_slot(slot, &pids, &iter, first_index) {
+		results[ret] = iter.index;
+		if (++ret == PIDVEC_SIZE)
+			break;
+	}
+	return ret;
+}
+
+void f2fs_destroy_trace_ios(void)
+{
+	pid_t pid[PIDVEC_SIZE];
+	pid_t next_pid = 0;
+	unsigned int found;
+
+	spin_lock(&pids_lock);
+	while ((found = gang_lookup_pids(pid, next_pid, PIDVEC_SIZE))) {
+		unsigned idx;
+
+		next_pid = pid[found - 1] + 1;
+		for (idx = 0; idx < found; idx++)
+			radix_tree_delete(&pids, pid[idx]);
+	}
+	spin_unlock(&pids_lock);
+}