Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1061 insertions, 0 deletions

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
new file mode 100644
index 000000000..16692c96e
--- /dev/null
+++ b/fs/f2fs/extent_cache.c
@@ -0,0 +1,1061 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * f2fs extent cache support
+ *
+ * Copyright (c) 2015 Motorola Mobility
+ * Copyright (c) 2015 Samsung Electronics
+ * Authors: Jaegeuk Kim <jaegeuk@kernel.org>
+ *          Chao Yu <chao2.yu@samsung.com>
+ */
+
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include <trace/events/f2fs.h>
+
+bool sanity_check_extent_cache(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct extent_info *ei;
+
+	if (!fi->extent_tree[EX_READ])
+		return true;
+
+	ei = &fi->extent_tree[EX_READ]->largest;
+
+	if (ei->len &&
+		(!f2fs_is_valid_blkaddr(sbi, ei->blk,
+					DATA_GENERIC_ENHANCE) ||
+		!f2fs_is_valid_blkaddr(sbi, ei->blk + ei->len - 1,
+					DATA_GENERIC_ENHANCE))) {
+		set_sbi_flag(sbi, SBI_NEED_FSCK);
+		f2fs_warn(sbi, "%s: inode (ino=%lx) extent info [%u, %u, %u] is incorrect, run fsck to fix",
+			  __func__, inode->i_ino,
+			  ei->blk, ei->fofs, ei->len);
+		return false;
+	}
+	return true;
+}
+
+static void __set_extent_info(struct extent_info *ei,
+				unsigned int fofs, unsigned int len,
+				block_t blk, bool keep_clen,
+				enum extent_type type)
+{
+	ei->fofs = fofs;
+	ei->len = len;
+
+	if (type == EX_READ) {
+		ei->blk = blk;
+		if (keep_clen)
+			return;
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+		ei->c_len = 0;
+#endif
+	}
+}
+
+static bool __may_read_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (!test_opt(sbi, READ_EXTENT_CACHE))
+		return false;
+	if (is_inode_flag_set(inode, FI_NO_EXTENT))
+		return false;
+	if (is_inode_flag_set(inode, FI_COMPRESSED_FILE) &&
+			 !f2fs_sb_has_readonly(sbi))
+		return false;
+	return S_ISREG(inode->i_mode);
+}
+
+static bool __init_may_extent_tree(struct inode *inode, enum extent_type type)
+{
+	if (type == EX_READ)
+		return __may_read_extent_tree(inode);
+	return false;
+}
+
+static bool __may_extent_tree(struct inode *inode, enum extent_type type)
+{
+	/*
+	 * for recovered files during mount do not create extents
+	 * if shrinker is not registered.
+	 */
+	if (list_empty(&F2FS_I_SB(inode)->s_list))
+		return false;
+
+	return __init_may_extent_tree(inode, type);
+}
+
+static void __try_update_largest_extent(struct extent_tree *et,
+						struct extent_node *en)
+{
+	if (et->type != EX_READ)
+		return;
+	if (en->ei.len <= et->largest.len)
+		return;
+
+	et->largest = en->ei;
+	et->largest_updated = true;
+}
+
+static bool __is_extent_mergeable(struct extent_info *back,
+		struct extent_info *front, enum extent_type type)
+{
+	if (type == EX_READ) {
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+		if (back->c_len && back->len != back->c_len)
+			return false;
+		if (front->c_len && front->len != front->c_len)
+			return false;
+#endif
+		return (back->fofs + back->len == front->fofs &&
+				back->blk + back->len == front->blk);
+	}
+	return false;
+}
+
+static bool __is_back_mergeable(struct extent_info *cur,
+		struct extent_info *back, enum extent_type type)
+{
+	return __is_extent_mergeable(back, cur, type);
+}
+
+static bool __is_front_mergeable(struct extent_info *cur,
+		struct extent_info *front, enum extent_type type)
+{
+	return __is_extent_mergeable(cur, front, type);
+}
+
+static struct rb_entry *__lookup_rb_tree_fast(struct rb_entry *cached_re,
+							unsigned int ofs)
+{
+	if (cached_re) {
+		if (cached_re->ofs <= ofs &&
+				cached_re->ofs + cached_re->len > ofs) {
+			return cached_re;
+		}
+	}
+	return NULL;
+}
+
+static struct rb_entry *__lookup_rb_tree_slow(struct rb_root_cached *root,
+							unsigned int ofs)
+{
+	struct rb_node *node = root->rb_root.rb_node;
+	struct rb_entry *re;
+
+	while (node) {
+		re = rb_entry(node, struct rb_entry, rb_node);
+
+		if (ofs < re->ofs)
+			node = node->rb_left;
+		else if (ofs >= re->ofs + re->len)
+			node = node->rb_right;
+		else
+			return re;
+	}
+	return NULL;
+}
+
+struct rb_entry *f2fs_lookup_rb_tree(struct rb_root_cached *root,
+				struct rb_entry *cached_re, unsigned int ofs)
+{
+	struct rb_entry *re;
+
+	re = __lookup_rb_tree_fast(cached_re, ofs);
+	if (!re)
+		return __lookup_rb_tree_slow(root, ofs);
+
+	return re;
+}
+
+struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
+				struct rb_root_cached *root,
+				struct rb_node **parent,
+				unsigned int ofs, bool *leftmost)
+{
+	struct rb_node **p = &root->rb_root.rb_node;
+	struct rb_entry *re;
+
+	while (*p) {
+		*parent = *p;
+		re = rb_entry(*parent, struct rb_entry, rb_node);
+
+		if (ofs < re->ofs) {
+			p = &(*p)->rb_left;
+		} else if (ofs >= re->ofs + re->len) {
+			p = &(*p)->rb_right;
+			*leftmost = false;
+		} else {
+			f2fs_bug_on(sbi, 1);
+		}
+	}
+
+	return p;
+}
+
+/*
+ * lookup rb entry in position of @ofs in rb-tree,
+ * if hit, return the entry, otherwise, return NULL
+ * @prev_ex: extent before ofs
+ * @next_ex: extent after ofs
+ * @insert_p: insert point for new extent at ofs
+ * in order to simpfy the insertion after.
+ * tree must stay unchanged between lookup and insertion.
+ */
+struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root,
+				struct rb_entry *cached_re,
+				unsigned int ofs,
+				struct rb_entry **prev_entry,
+				struct rb_entry **next_entry,
+				struct rb_node ***insert_p,
+				struct rb_node **insert_parent,
+				bool force, bool *leftmost)
+{
+	struct rb_node **pnode = &root->rb_root.rb_node;
+	struct rb_node *parent = NULL, *tmp_node;
+	struct rb_entry *re = cached_re;
+
+	*insert_p = NULL;
+	*insert_parent = NULL;
+	*prev_entry = NULL;
+	*next_entry = NULL;
+
+	if (RB_EMPTY_ROOT(&root->rb_root))
+		return NULL;
+
+	if (re) {
+		if (re->ofs <= ofs && re->ofs + re->len > ofs)
+			goto lookup_neighbors;
+	}
+
+	if (leftmost)
+		*leftmost = true;
+
+	while (*pnode) {
+		parent = *pnode;
+		re = rb_entry(*pnode, struct rb_entry, rb_node);
+
+		if (ofs < re->ofs) {
+			pnode = &(*pnode)->rb_left;
+		} else if (ofs >= re->ofs + re->len) {
+			pnode = &(*pnode)->rb_right;
+			if (leftmost)
+				*leftmost = false;
+		} else {
+			goto lookup_neighbors;
+		}
+	}
+
+	*insert_p = pnode;
+	*insert_parent = parent;
+
+	re = rb_entry(parent, struct rb_entry, rb_node);
+	tmp_node = parent;
+	if (parent && ofs > re->ofs)
+		tmp_node = rb_next(parent);
+	*next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
+
+	tmp_node = parent;
+	if (parent && ofs < re->ofs)
+		tmp_node = rb_prev(parent);
+	*prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
+	return NULL;
+
+lookup_neighbors:
+	if (ofs == re->ofs || force) {
+		/* lookup prev node for merging backward later */
+		tmp_node = rb_prev(&re->rb_node);
+		*prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
+	}
+	if (ofs == re->ofs + re->len - 1 || force) {
+		/* lookup next node for merging frontward later */
+		tmp_node = rb_next(&re->rb_node);
+		*next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
+	}
+	return re;
+}
+
+bool f2fs_check_rb_tree_consistence(struct f2fs_sb_info *sbi,
+				struct rb_root_cached *root)
+{
+#ifdef CONFIG_F2FS_CHECK_FS
+	struct rb_node *cur = rb_first_cached(root), *next;
+	struct rb_entry *cur_re, *next_re;
+
+	if (!cur)
+		return true;
+
+	while (cur) {
+		next = rb_next(cur);
+		if (!next)
+			return true;
+
+		cur_re = rb_entry(cur, struct rb_entry, rb_node);
+		next_re = rb_entry(next, struct rb_entry, rb_node);
+
+		if (cur_re->ofs + cur_re->len > next_re->ofs) {
+			f2fs_info(sbi, "inconsistent rbtree, cur(%u, %u) next(%u, %u)",
+				  cur_re->ofs, cur_re->len,
+				  next_re->ofs, next_re->len);
+			return false;
+		}
+		cur = next;
+	}
+#endif
+	return true;
+}
+
+static struct kmem_cache *extent_tree_slab;
+static struct kmem_cache *extent_node_slab;
+
+static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct rb_node *parent, struct rb_node **p,
+				bool leftmost)
+{
+	struct extent_tree_info *eti = &sbi->extent_tree[et->type];
+	struct extent_node *en;
+
+	en = f2fs_kmem_cache_alloc(extent_node_slab, GFP_ATOMIC, false, sbi);
+	if (!en)
+		return NULL;
+
+	en->ei = *ei;
+	INIT_LIST_HEAD(&en->list);
+	en->et = et;
+
+	rb_link_node(&en->rb_node, parent, p);
+	rb_insert_color_cached(&en->rb_node, &et->root, leftmost);
+	atomic_inc(&et->node_cnt);
+	atomic_inc(&eti->total_ext_node);
+	return en;
+}
+
+static void __detach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	struct extent_tree_info *eti = &sbi->extent_tree[et->type];
+
+	rb_erase_cached(&en->rb_node, &et->root);
+	atomic_dec(&et->node_cnt);
+	atomic_dec(&eti->total_ext_node);
+
+	if (et->cached_en == en)
+		et->cached_en = NULL;
+	kmem_cache_free(extent_node_slab, en);
+}
+
+/*
+ * Flow to release an extent_node:
+ * 1. list_del_init
+ * 2. __detach_extent_node
+ * 3. kmem_cache_free.
+ */
+static void __release_extent_node(struct f2fs_sb_info *sbi,
+			struct extent_tree *et, struct extent_node *en)
+{
+	struct extent_tree_info *eti = &sbi->extent_tree[et->type];
+
+	spin_lock(&eti->extent_lock);
+	f2fs_bug_on(sbi, list_empty(&en->list));
+	list_del_init(&en->list);
+	spin_unlock(&eti->extent_lock);
+
+	__detach_extent_node(sbi, et, en);
+}
+
+static struct extent_tree *__grab_extent_tree(struct inode *inode,
+						enum extent_type type)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree_info *eti = &sbi->extent_tree[type];
+	struct extent_tree *et;
+	nid_t ino = inode->i_ino;
+
+	mutex_lock(&eti->extent_tree_lock);
+	et = radix_tree_lookup(&eti->extent_tree_root, ino);
+	if (!et) {
+		et = f2fs_kmem_cache_alloc(extent_tree_slab,
+					GFP_NOFS, true, NULL);
+		f2fs_radix_tree_insert(&eti->extent_tree_root, ino, et);
+		memset(et, 0, sizeof(struct extent_tree));
+		et->ino = ino;
+		et->type = type;
+		et->root = RB_ROOT_CACHED;
+		et->cached_en = NULL;
+		rwlock_init(&et->lock);
+		INIT_LIST_HEAD(&et->list);
+		atomic_set(&et->node_cnt, 0);
+		atomic_inc(&eti->total_ext_tree);
+	} else {
+		atomic_dec(&eti->total_zombie_tree);
+		list_del_init(&et->list);
+	}
+	mutex_unlock(&eti->extent_tree_lock);
+
+	/* never died until evict_inode */
+	F2FS_I(inode)->extent_tree[type] = et;
+
+	return et;
+}
+
+static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
+					struct extent_tree *et)
+{
+	struct rb_node *node, *next;
+	struct extent_node *en;
+	unsigned int count = atomic_read(&et->node_cnt);
+
+	node = rb_first_cached(&et->root);
+	while (node) {
+		next = rb_next(node);
+		en = rb_entry(node, struct extent_node, rb_node);
+		__release_extent_node(sbi, et, en);
+		node = next;
+	}
+
+	return count - atomic_read(&et->node_cnt);
+}
+
+static void __drop_largest_extent(struct extent_tree *et,
+					pgoff_t fofs, unsigned int len)
+{
+	if (fofs < et->largest.fofs + et->largest.len &&
+			fofs + len > et->largest.fofs) {
+		et->largest.len = 0;
+		et->largest_updated = true;
+	}
+}
+
+void f2fs_init_read_extent_tree(struct inode *inode, struct page *ipage)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree_info *eti = &sbi->extent_tree[EX_READ];
+	struct f2fs_extent *i_ext = &F2FS_INODE(ipage)->i_ext;
+	struct extent_tree *et;
+	struct extent_node *en;
+	struct extent_info ei;
+
+	if (!__may_extent_tree(inode, EX_READ)) {
+		/* drop largest read extent */
+		if (i_ext && i_ext->len) {
+			f2fs_wait_on_page_writeback(ipage, NODE, true, true);
+			i_ext->len = 0;
+			set_page_dirty(ipage);
+		}
+		goto out;
+	}
+
+	et = __grab_extent_tree(inode, EX_READ);
+
+	if (!i_ext || !i_ext->len)
+		goto out;
+
+	get_read_extent_info(&ei, i_ext);
+
+	write_lock(&et->lock);
+	if (atomic_read(&et->node_cnt))
+		goto unlock_out;
+
+	en = __attach_extent_node(sbi, et, &ei, NULL,
+				&et->root.rb_root.rb_node, true);
+	if (en) {
+		et->largest = en->ei;
+		et->cached_en = en;
+
+		spin_lock(&eti->extent_lock);
+		list_add_tail(&en->list, &eti->extent_list);
+		spin_unlock(&eti->extent_lock);
+	}
+unlock_out:
+	write_unlock(&et->lock);
+out:
+	if (!F2FS_I(inode)->extent_tree[EX_READ])
+		set_inode_flag(inode, FI_NO_EXTENT);
+}
+
+void f2fs_init_extent_tree(struct inode *inode)
+{
+	/* initialize read cache */
+	if (__init_may_extent_tree(inode, EX_READ))
+		__grab_extent_tree(inode, EX_READ);
+}
+
+static bool __lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
+			struct extent_info *ei, enum extent_type type)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree_info *eti = &sbi->extent_tree[type];
+	struct extent_tree *et = F2FS_I(inode)->extent_tree[type];
+	struct extent_node *en;
+	bool ret = false;
+
+	if (!et)
+		return false;
+
+	trace_f2fs_lookup_extent_tree_start(inode, pgofs, type);
+
+	read_lock(&et->lock);
+
+	if (type == EX_READ &&
+			et->largest.fofs <= pgofs &&
+			et->largest.fofs + et->largest.len > pgofs) {
+		*ei = et->largest;
+		ret = true;
+		stat_inc_largest_node_hit(sbi);
+		goto out;
+	}
+
+	en = (struct extent_node *)f2fs_lookup_rb_tree(&et->root,
+				(struct rb_entry *)et->cached_en, pgofs);
+	if (!en)
+		goto out;
+
+	if (en == et->cached_en)
+		stat_inc_cached_node_hit(sbi, type);
+	else
+		stat_inc_rbtree_node_hit(sbi, type);
+
+	*ei = en->ei;
+	spin_lock(&eti->extent_lock);
+	if (!list_empty(&en->list)) {
+		list_move_tail(&en->list, &eti->extent_list);
+		et->cached_en = en;
+	}
+	spin_unlock(&eti->extent_lock);
+	ret = true;
+out:
+	stat_inc_total_hit(sbi, type);
+	read_unlock(&et->lock);
+
+	if (type == EX_READ)
+		trace_f2fs_lookup_read_extent_tree_end(inode, pgofs, ei);
+	return ret;
+}
+
+static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct extent_node *prev_ex,
+				struct extent_node *next_ex)
+{
+	struct extent_tree_info *eti = &sbi->extent_tree[et->type];
+	struct extent_node *en = NULL;
+
+	if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei, et->type)) {
+		prev_ex->ei.len += ei->len;
+		ei = &prev_ex->ei;
+		en = prev_ex;
+	}
+
+	if (next_ex && __is_front_mergeable(ei, &next_ex->ei, et->type)) {
+		next_ex->ei.fofs = ei->fofs;
+		next_ex->ei.len += ei->len;
+		if (et->type == EX_READ)
+			next_ex->ei.blk = ei->blk;
+		if (en)
+			__release_extent_node(sbi, et, prev_ex);
+
+		en = next_ex;
+	}
+
+	if (!en)
+		return NULL;
+
+	__try_update_largest_extent(et, en);
+
+	spin_lock(&eti->extent_lock);
+	if (!list_empty(&en->list)) {
+		list_move_tail(&en->list, &eti->extent_list);
+		et->cached_en = en;
+	}
+	spin_unlock(&eti->extent_lock);
+	return en;
+}
+
+static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct rb_node **insert_p,
+				struct rb_node *insert_parent,
+				bool leftmost)
+{
+	struct extent_tree_info *eti = &sbi->extent_tree[et->type];
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct extent_node *en = NULL;
+
+	if (insert_p && insert_parent) {
+		parent = insert_parent;
+		p = insert_p;
+		goto do_insert;
+	}
+
+	leftmost = true;
+
+	p = f2fs_lookup_rb_tree_for_insert(sbi, &et->root, &parent,
+						ei->fofs, &leftmost);
+do_insert:
+	en = __attach_extent_node(sbi, et, ei, parent, p, leftmost);
+	if (!en)
+		return NULL;
+
+	__try_update_largest_extent(et, en);
+
+	/* update in global extent list */
+	spin_lock(&eti->extent_lock);
+	list_add_tail(&en->list, &eti->extent_list);
+	et->cached_en = en;
+	spin_unlock(&eti->extent_lock);
+	return en;
+}
+
+static void __update_extent_tree_range(struct inode *inode,
+			struct extent_info *tei, enum extent_type type)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree[type];
+	struct extent_node *en = NULL, *en1 = NULL;
+	struct extent_node *prev_en = NULL, *next_en = NULL;
+	struct extent_info ei, dei, prev;
+	struct rb_node **insert_p = NULL, *insert_parent = NULL;
+	unsigned int fofs = tei->fofs, len = tei->len;
+	unsigned int end = fofs + len;
+	bool updated = false;
+	bool leftmost = false;
+
+	if (!et)
+		return;
+
+	if (type == EX_READ)
+		trace_f2fs_update_read_extent_tree_range(inode, fofs, len,
+						tei->blk, 0);
+	write_lock(&et->lock);
+
+	if (type == EX_READ) {
+		if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
+			write_unlock(&et->lock);
+			return;
+		}
+
+		prev = et->largest;
+		dei.len = 0;
+
+		/*
+		 * drop largest extent before lookup, in case it's already
+		 * been shrunk from extent tree
+		 */
+		__drop_largest_extent(et, fofs, len);
+	}
+
+	/* 1. lookup first extent node in range [fofs, fofs + len - 1] */
+	en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
+					(struct rb_entry *)et->cached_en, fofs,
+					(struct rb_entry **)&prev_en,
+					(struct rb_entry **)&next_en,
+					&insert_p, &insert_parent, false,
+					&leftmost);
+	if (!en)
+		en = next_en;
+
+	/* 2. invlidate all extent nodes in range [fofs, fofs + len - 1] */
+	while (en && en->ei.fofs < end) {
+		unsigned int org_end;
+		int parts = 0;	/* # of parts current extent split into */
+
+		next_en = en1 = NULL;
+
+		dei = en->ei;
+		org_end = dei.fofs + dei.len;
+		f2fs_bug_on(sbi, fofs >= org_end);
+
+		if (fofs > dei.fofs && (type != EX_READ ||
+				fofs - dei.fofs >= F2FS_MIN_EXTENT_LEN)) {
+			en->ei.len = fofs - en->ei.fofs;
+			prev_en = en;
+			parts = 1;
+		}
+
+		if (end < org_end && (type != EX_READ ||
+				org_end - end >= F2FS_MIN_EXTENT_LEN)) {
+			if (parts) {
+				__set_extent_info(&ei,
+					end, org_end - end,
+					end - dei.fofs + dei.blk, false,
+					type);
+				en1 = __insert_extent_tree(sbi, et, &ei,
+							NULL, NULL, true);
+				next_en = en1;
+			} else {
+				__set_extent_info(&en->ei,
+					end, en->ei.len - (end - dei.fofs),
+					en->ei.blk + (end - dei.fofs), true,
+					type);
+				next_en = en;
+			}
+			parts++;
+		}
+
+		if (!next_en) {
+			struct rb_node *node = rb_next(&en->rb_node);
+
+			next_en = rb_entry_safe(node, struct extent_node,
+						rb_node);
+		}
+
+		if (parts)
+			__try_update_largest_extent(et, en);
+		else
+			__release_extent_node(sbi, et, en);
+
+		/*
+		 * if original extent is split into zero or two parts, extent
+		 * tree has been altered by deletion or insertion, therefore
+		 * invalidate pointers regard to tree.
+		 */
+		if (parts != 1) {
+			insert_p = NULL;
+			insert_parent = NULL;
+		}
+		en = next_en;
+	}
+
+	/* 3. update extent in read extent cache */
+	BUG_ON(type != EX_READ);
+
+	if (tei->blk) {
+		__set_extent_info(&ei, fofs, len, tei->blk, false, EX_READ);
+		if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
+			__insert_extent_tree(sbi, et, &ei,
+					insert_p, insert_parent, leftmost);
+
+		/* give up extent_cache, if split and small updates happen */
+		if (dei.len >= 1 &&
+				prev.len < F2FS_MIN_EXTENT_LEN &&
+				et->largest.len < F2FS_MIN_EXTENT_LEN) {
+			et->largest.len = 0;
+			et->largest_updated = true;
+			set_inode_flag(inode, FI_NO_EXTENT);
+		}
+	}
+
+	if (is_inode_flag_set(inode, FI_NO_EXTENT))
+		__free_extent_tree(sbi, et);
+
+	if (et->largest_updated) {
+		et->largest_updated = false;
+		updated = true;
+	}
+
+	write_unlock(&et->lock);
+
+	if (updated)
+		f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+void f2fs_update_read_extent_tree_range_compressed(struct inode *inode,
+				pgoff_t fofs, block_t blkaddr, unsigned int llen,
+				unsigned int c_len)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree[EX_READ];
+	struct extent_node *en = NULL;
+	struct extent_node *prev_en = NULL, *next_en = NULL;
+	struct extent_info ei;
+	struct rb_node **insert_p = NULL, *insert_parent = NULL;
+	bool leftmost = false;
+
+	trace_f2fs_update_read_extent_tree_range(inode, fofs, llen,
+						blkaddr, c_len);
+
+	/* it is safe here to check FI_NO_EXTENT w/o et->lock in ro image */
+	if (is_inode_flag_set(inode, FI_NO_EXTENT))
+		return;
+
+	write_lock(&et->lock);
+
+	en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
+				(struct rb_entry *)et->cached_en, fofs,
+				(struct rb_entry **)&prev_en,
+				(struct rb_entry **)&next_en,
+				&insert_p, &insert_parent, false,
+				&leftmost);
+	if (en)
+		goto unlock_out;
+
+	__set_extent_info(&ei, fofs, llen, blkaddr, true, EX_READ);
+	ei.c_len = c_len;
+
+	if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
+		__insert_extent_tree(sbi, et, &ei,
+				insert_p, insert_parent, leftmost);
+unlock_out:
+	write_unlock(&et->lock);
+}
+#endif
+
+static void __update_extent_cache(struct dnode_of_data *dn, enum extent_type type)
+{
+	struct extent_info ei;
+
+	if (!__may_extent_tree(dn->inode, type))
+		return;
+
+	ei.fofs = f2fs_start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
+								dn->ofs_in_node;
+	ei.len = 1;
+
+	if (type == EX_READ) {
+		if (dn->data_blkaddr == NEW_ADDR)
+			ei.blk = NULL_ADDR;
+		else
+			ei.blk = dn->data_blkaddr;
+	}
+	__update_extent_tree_range(dn->inode, &ei, type);
+}
+
+static unsigned int __shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink,
+					enum extent_type type)
+{
+	struct extent_tree_info *eti = &sbi->extent_tree[type];
+	struct extent_tree *et, *next;
+	struct extent_node *en;
+	unsigned int node_cnt = 0, tree_cnt = 0;
+	int remained;
+
+	if (!atomic_read(&eti->total_zombie_tree))
+		goto free_node;
+
+	if (!mutex_trylock(&eti->extent_tree_lock))
+		goto out;
+
+	/* 1. remove unreferenced extent tree */
+	list_for_each_entry_safe(et, next, &eti->zombie_list, list) {
+		if (atomic_read(&et->node_cnt)) {
+			write_lock(&et->lock);
+			node_cnt += __free_extent_tree(sbi, et);
+			write_unlock(&et->lock);
+		}
+		f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
+		list_del_init(&et->list);
+		radix_tree_delete(&eti->extent_tree_root, et->ino);
+		kmem_cache_free(extent_tree_slab, et);
+		atomic_dec(&eti->total_ext_tree);
+		atomic_dec(&eti->total_zombie_tree);
+		tree_cnt++;
+
+		if (node_cnt + tree_cnt >= nr_shrink)
+			goto unlock_out;
+		cond_resched();
+	}
+	mutex_unlock(&eti->extent_tree_lock);
+
+free_node:
+	/* 2. remove LRU extent entries */
+	if (!mutex_trylock(&eti->extent_tree_lock))
+		goto out;
+
+	remained = nr_shrink - (node_cnt + tree_cnt);
+
+	spin_lock(&eti->extent_lock);
+	for (; remained > 0; remained--) {
+		if (list_empty(&eti->extent_list))
+			break;
+		en = list_first_entry(&eti->extent_list,
+					struct extent_node, list);
+		et = en->et;
+		if (!write_trylock(&et->lock)) {
+			/* refresh this extent node's position in extent list */
+			list_move_tail(&en->list, &eti->extent_list);
+			continue;
+		}
+
+		list_del_init(&en->list);
+		spin_unlock(&eti->extent_lock);
+
+		__detach_extent_node(sbi, et, en);
+
+		write_unlock(&et->lock);
+		node_cnt++;
+		spin_lock(&eti->extent_lock);
+	}
+	spin_unlock(&eti->extent_lock);
+
+unlock_out:
+	mutex_unlock(&eti->extent_tree_lock);
+out:
+	trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt, type);
+
+	return node_cnt + tree_cnt;
+}
+
+/* read extent cache operations */
+bool f2fs_lookup_read_extent_cache(struct inode *inode, pgoff_t pgofs,
+				struct extent_info *ei)
+{
+	if (!__may_extent_tree(inode, EX_READ))
+		return false;
+
+	return __lookup_extent_tree(inode, pgofs, ei, EX_READ);
+}
+
+void f2fs_update_read_extent_cache(struct dnode_of_data *dn)
+{
+	return __update_extent_cache(dn, EX_READ);
+}
+
+void f2fs_update_read_extent_cache_range(struct dnode_of_data *dn,
+				pgoff_t fofs, block_t blkaddr, unsigned int len)
+{
+	struct extent_info ei = {
+		.fofs = fofs,
+		.len = len,
+		.blk = blkaddr,
+	};
+
+	if (!__may_extent_tree(dn->inode, EX_READ))
+		return;
+
+	__update_extent_tree_range(dn->inode, &ei, EX_READ);
+}
+
+unsigned int f2fs_shrink_read_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	if (!test_opt(sbi, READ_EXTENT_CACHE))
+		return 0;
+
+	return __shrink_extent_tree(sbi, nr_shrink, EX_READ);
+}
+
+static unsigned int __destroy_extent_node(struct inode *inode,
+					enum extent_type type)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree[type];
+	unsigned int node_cnt = 0;
+
+	if (!et || !atomic_read(&et->node_cnt))
+		return 0;
+
+	write_lock(&et->lock);
+	node_cnt = __free_extent_tree(sbi, et);
+	write_unlock(&et->lock);
+
+	return node_cnt;
+}
+
+void f2fs_destroy_extent_node(struct inode *inode)
+{
+	__destroy_extent_node(inode, EX_READ);
+}
+
+static void __drop_extent_tree(struct inode *inode, enum extent_type type)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et = F2FS_I(inode)->extent_tree[type];
+	bool updated = false;
+
+	if (!__may_extent_tree(inode, type))
+		return;
+
+	write_lock(&et->lock);
+	__free_extent_tree(sbi, et);
+	if (type == EX_READ) {
+		set_inode_flag(inode, FI_NO_EXTENT);
+		if (et->largest.len) {
+			et->largest.len = 0;
+			updated = true;
+		}
+	}
+	write_unlock(&et->lock);
+	if (updated)
+		f2fs_mark_inode_dirty_sync(inode, true);
+}
+
+void f2fs_drop_extent_tree(struct inode *inode)
+{
+	__drop_extent_tree(inode, EX_READ);
+}
+
+static void __destroy_extent_tree(struct inode *inode, enum extent_type type)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree_info *eti = &sbi->extent_tree[type];
+	struct extent_tree *et = F2FS_I(inode)->extent_tree[type];
+	unsigned int node_cnt = 0;
+
+	if (!et)
+		return;
+
+	if (inode->i_nlink && !is_bad_inode(inode) &&
+					atomic_read(&et->node_cnt)) {
+		mutex_lock(&eti->extent_tree_lock);
+		list_add_tail(&et->list, &eti->zombie_list);
+		atomic_inc(&eti->total_zombie_tree);
+		mutex_unlock(&eti->extent_tree_lock);
+		return;
+	}
+
+	/* free all extent info belong to this extent tree */
+	node_cnt = __destroy_extent_node(inode, type);
+
+	/* delete extent tree entry in radix tree */
+	mutex_lock(&eti->extent_tree_lock);
+	f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
+	radix_tree_delete(&eti->extent_tree_root, inode->i_ino);
+	kmem_cache_free(extent_tree_slab, et);
+	atomic_dec(&eti->total_ext_tree);
+	mutex_unlock(&eti->extent_tree_lock);
+
+	F2FS_I(inode)->extent_tree[type] = NULL;
+
+	trace_f2fs_destroy_extent_tree(inode, node_cnt, type);
+}
+
+void f2fs_destroy_extent_tree(struct inode *inode)
+{
+	__destroy_extent_tree(inode, EX_READ);
+}
+
+static void __init_extent_tree_info(struct extent_tree_info *eti)
+{
+	INIT_RADIX_TREE(&eti->extent_tree_root, GFP_NOIO);
+	mutex_init(&eti->extent_tree_lock);
+	INIT_LIST_HEAD(&eti->extent_list);
+	spin_lock_init(&eti->extent_lock);
+	atomic_set(&eti->total_ext_tree, 0);
+	INIT_LIST_HEAD(&eti->zombie_list);
+	atomic_set(&eti->total_zombie_tree, 0);
+	atomic_set(&eti->total_ext_node, 0);
+}
+
+void f2fs_init_extent_cache_info(struct f2fs_sb_info *sbi)
+{
+	__init_extent_tree_info(&sbi->extent_tree[EX_READ]);
+}
+
+int __init f2fs_create_extent_cache(void)
+{
+	extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
+			sizeof(struct extent_tree));
+	if (!extent_tree_slab)
+		return -ENOMEM;
+	extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
+			sizeof(struct extent_node));
+	if (!extent_node_slab) {
+		kmem_cache_destroy(extent_tree_slab);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void f2fs_destroy_extent_cache(void)
+{
+	kmem_cache_destroy(extent_node_slab);
+	kmem_cache_destroy(extent_tree_slab);
+}