Merge tag 'for-f2fs-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
 "The major work includes fixing and enhancing the existing extent_cache
  feature, which has been well settling down so far and now it becomes a
  default mount option accordingly.

  Also, this version newly registers a f2fs memory shrinker to reclaim
  several objects consumed by a couple of data structures in order to
  avoid memory pressures.

  Another new feature is to add ioctl(F2FS_GARBAGE_COLLECT) which
  triggers a cleaning job explicitly by users.

  Most of the other patches are to fix bugs occurred in the corner cases
  across the whole code area"

* tag 'for-f2fs-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (85 commits)
  f2fs: upset segment_info repair
  f2fs: avoid accessing NULL pointer in f2fs_drop_largest_extent
  f2fs: update extent tree in batches
  f2fs: fix to release inode correctly
  f2fs: handle f2fs_truncate error correctly
  f2fs: avoid unneeded initializing when converting inline dentry
  f2fs: atomically set inode->i_flags
  f2fs: fix wrong pointer access during try_to_free_nids
  f2fs: use __GFP_NOFAIL to avoid infinite loop
  f2fs: lookup neighbor extent nodes for merging later
  f2fs: split __insert_extent_tree_ret for readability
  f2fs: kill dead code in __insert_extent_tree
  f2fs: adjust showing of extent cache stat
  f2fs: add largest/cached stat in extent cache
  f2fs: fix incorrect mapping for bmap
  f2fs: add annotation for space utilization of regular/inline dentry
  f2fs: fix to update cached_en of extent tree properly
  f2fs: fix typo
  f2fs: check the node block address of newly allocated nid
  f2fs: go out for insert_inode_locked failure
  ...

1 files changed, 139 insertions, 0 deletions

diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
new file mode 100644
index 000000000000..da0d8e0b55a5
--- /dev/null
+++ b/fs/f2fs/shrinker.c
@@ -0,0 +1,139 @@
+/*
+ * f2fs shrinker support
+ *   the basic infra was copied from fs/ubifs/shrinker.c
+ *
+ * Copyright (c) 2015 Motorola Mobility
+ * Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+
+#include "f2fs.h"
+
+static LIST_HEAD(f2fs_list);
+static DEFINE_SPINLOCK(f2fs_list_lock);
+static unsigned int shrinker_run_no;
+
+static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
+{
+	return NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
+}
+
+static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
+{
+	if (NM_I(sbi)->fcnt > NAT_ENTRY_PER_BLOCK)
+		return NM_I(sbi)->fcnt - NAT_ENTRY_PER_BLOCK;
+	return 0;
+}
+
+static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi)
+{
+	return sbi->total_ext_tree + atomic_read(&sbi->total_ext_node);
+}
+
+unsigned long f2fs_shrink_count(struct shrinker *shrink,
+				struct shrink_control *sc)
+{
+	struct f2fs_sb_info *sbi;
+	struct list_head *p;
+	unsigned long count = 0;
+
+	spin_lock(&f2fs_list_lock);
+	p = f2fs_list.next;
+	while (p != &f2fs_list) {
+		sbi = list_entry(p, struct f2fs_sb_info, s_list);
+
+		/* stop f2fs_put_super */
+		if (!mutex_trylock(&sbi->umount_mutex)) {
+			p = p->next;
+			continue;
+		}
+		spin_unlock(&f2fs_list_lock);
+
+		/* count extent cache entries */
+		count += __count_extent_cache(sbi);
+
+		/* shrink clean nat cache entries */
+		count += __count_nat_entries(sbi);
+
+		/* count free nids cache entries */
+		count += __count_free_nids(sbi);
+
+		spin_lock(&f2fs_list_lock);
+		p = p->next;
+		mutex_unlock(&sbi->umount_mutex);
+	}
+	spin_unlock(&f2fs_list_lock);
+	return count;
+}
+
+unsigned long f2fs_shrink_scan(struct shrinker *shrink,
+				struct shrink_control *sc)
+{
+	unsigned long nr = sc->nr_to_scan;
+	struct f2fs_sb_info *sbi;
+	struct list_head *p;
+	unsigned int run_no;
+	unsigned long freed = 0;
+
+	spin_lock(&f2fs_list_lock);
+	do {
+		run_no = ++shrinker_run_no;
+	} while (run_no == 0);
+	p = f2fs_list.next;
+	while (p != &f2fs_list) {
+		sbi = list_entry(p, struct f2fs_sb_info, s_list);
+
+		if (sbi->shrinker_run_no == run_no)
+			break;
+
+		/* stop f2fs_put_super */
+		if (!mutex_trylock(&sbi->umount_mutex)) {
+			p = p->next;
+			continue;
+		}
+		spin_unlock(&f2fs_list_lock);
+
+		sbi->shrinker_run_no = run_no;
+
+		/* shrink extent cache entries */
+		freed += f2fs_shrink_extent_tree(sbi, nr >> 1);
+
+		/* shrink clean nat cache entries */
+		if (freed < nr)
+			freed += try_to_free_nats(sbi, nr - freed);
+
+		/* shrink free nids cache entries */
+		if (freed < nr)
+			freed += try_to_free_nids(sbi, nr - freed);
+
+		spin_lock(&f2fs_list_lock);
+		p = p->next;
+		list_move_tail(&sbi->s_list, &f2fs_list);
+		mutex_unlock(&sbi->umount_mutex);
+		if (freed >= nr)
+			break;
+	}
+	spin_unlock(&f2fs_list_lock);
+	return freed;
+}
+
+void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
+{
+	spin_lock(&f2fs_list_lock);
+	list_add_tail(&sbi->s_list, &f2fs_list);
+	spin_unlock(&f2fs_list_lock);
+}
+
+void f2fs_leave_shrinker(struct f2fs_sb_info *sbi)
+{
+	f2fs_shrink_extent_tree(sbi, __count_extent_cache(sbi));
+
+	spin_lock(&f2fs_list_lock);
+	list_del(&sbi->s_list);
+	spin_unlock(&f2fs_list_lock);
+}