f2fs: add new ioctl F2FS_IOC_GARBAGE_COLLECT
When background gc is off, the only way to trigger gc is executing
a force gc in some operations who wants to grab space in disk.
The executing condition is limited: to execute force gc, we should
wait for the time when there is almost no more free section for LFS
allocation. This seems not reasonable for our user who wants to
control triggering gc by himself.
This patch introduces F2FS_IOC_GARBAGE_COLLECT interface for
triggering garbage collection by using ioctl. It provides our users
one more option to trigger gc.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index b4a65be..c5a055b 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -19,6 +19,12 @@
#define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */
#define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */
+/*
+ * with this macro, we can control the max time we do garbage collection,
+ * when user triggers batch mode gc by ioctl.
+ */
+#define F2FS_BATCH_GC_MAX_NUM 16
+
/* Search max. number of dirty segments to select a victim segment */
#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */