Initial import

1 files changed, 1864 insertions, 0 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
new file mode 100644
index 000000000..1e1aae669
--- /dev/null
+++ b/fs/f2fs/data.c
@@ -0,0 +1,1864 @@
+/*
+ * fs/f2fs/data.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ *
+ * 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 <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/prefetch.h>
+#include <linux/uio.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "trace.h"
+#include <trace/events/f2fs.h>
+
+static struct kmem_cache *extent_tree_slab;
+static struct kmem_cache *extent_node_slab;
+
+static void f2fs_read_end_io(struct bio *bio, int err)
+{
+	struct bio_vec *bvec;
+	int i;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		struct page *page = bvec->bv_page;
+
+		if (!err) {
+			SetPageUptodate(page);
+		} else {
+			ClearPageUptodate(page);
+			SetPageError(page);
+		}
+		unlock_page(page);
+	}
+	bio_put(bio);
+}
+
+static void f2fs_write_end_io(struct bio *bio, int err)
+{
+	struct f2fs_sb_info *sbi = bio->bi_private;
+	struct bio_vec *bvec;
+	int i;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		struct page *page = bvec->bv_page;
+
+		if (unlikely(err)) {
+			set_page_dirty(page);
+			set_bit(AS_EIO, &page->mapping->flags);
+			f2fs_stop_checkpoint(sbi);
+		}
+		end_page_writeback(page);
+		dec_page_count(sbi, F2FS_WRITEBACK);
+	}
+
+	if (!get_pages(sbi, F2FS_WRITEBACK) &&
+			!list_empty(&sbi->cp_wait.task_list))
+		wake_up(&sbi->cp_wait);
+
+	bio_put(bio);
+}
+
+/*
+ * Low-level block read/write IO operations.
+ */
+static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
+				int npages, bool is_read)
+{
+	struct bio *bio;
+
+	/* No failure on bio allocation */
+	bio = bio_alloc(GFP_NOIO, npages);
+
+	bio->bi_bdev = sbi->sb->s_bdev;
+	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
+	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
+	bio->bi_private = sbi;
+
+	return bio;
+}
+
+static void __submit_merged_bio(struct f2fs_bio_info *io)
+{
+	struct f2fs_io_info *fio = &io->fio;
+
+	if (!io->bio)
+		return;
+
+	if (is_read_io(fio->rw))
+		trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
+	else
+		trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
+
+	submit_bio(fio->rw, io->bio);
+	io->bio = NULL;
+}
+
+void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
+				enum page_type type, int rw)
+{
+	enum page_type btype = PAGE_TYPE_OF_BIO(type);
+	struct f2fs_bio_info *io;
+
+	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
+
+	down_write(&io->io_rwsem);
+
+	/* change META to META_FLUSH in the checkpoint procedure */
+	if (type >= META_FLUSH) {
+		io->fio.type = META_FLUSH;
+		if (test_opt(sbi, NOBARRIER))
+			io->fio.rw = WRITE_FLUSH | REQ_META | REQ_PRIO;
+		else
+			io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
+	}
+	__submit_merged_bio(io);
+	up_write(&io->io_rwsem);
+}
+
+/*
+ * Fill the locked page with data located in the block address.
+ * Return unlocked page.
+ */
+int f2fs_submit_page_bio(struct f2fs_sb_info *sbi, struct page *page,
+					struct f2fs_io_info *fio)
+{
+	struct bio *bio;
+
+	trace_f2fs_submit_page_bio(page, fio);
+	f2fs_trace_ios(page, fio, 0);
+
+	/* Allocate a new bio */
+	bio = __bio_alloc(sbi, fio->blk_addr, 1, is_read_io(fio->rw));
+
+	if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
+		bio_put(bio);
+		f2fs_put_page(page, 1);
+		return -EFAULT;
+	}
+
+	submit_bio(fio->rw, bio);
+	return 0;
+}
+
+void f2fs_submit_page_mbio(struct f2fs_sb_info *sbi, struct page *page,
+					struct f2fs_io_info *fio)
+{
+	enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
+	struct f2fs_bio_info *io;
+	bool is_read = is_read_io(fio->rw);
+
+	io = is_read ? &sbi->read_io : &sbi->write_io[btype];
+
+	verify_block_addr(sbi, fio->blk_addr);
+
+	down_write(&io->io_rwsem);
+
+	if (!is_read)
+		inc_page_count(sbi, F2FS_WRITEBACK);
+
+	if (io->bio && (io->last_block_in_bio != fio->blk_addr - 1 ||
+						io->fio.rw != fio->rw))
+		__submit_merged_bio(io);
+alloc_new:
+	if (io->bio == NULL) {
+		int bio_blocks = MAX_BIO_BLOCKS(sbi);
+
+		io->bio = __bio_alloc(sbi, fio->blk_addr, bio_blocks, is_read);
+		io->fio = *fio;
+	}
+
+	if (bio_add_page(io->bio, page, PAGE_CACHE_SIZE, 0) <
+							PAGE_CACHE_SIZE) {
+		__submit_merged_bio(io);
+		goto alloc_new;
+	}
+
+	io->last_block_in_bio = fio->blk_addr;
+	f2fs_trace_ios(page, fio, 0);
+
+	up_write(&io->io_rwsem);
+	trace_f2fs_submit_page_mbio(page, fio);
+}
+
+/*
+ * Lock ordering for the change of data block address:
+ * ->data_page
+ *  ->node_page
+ *    update block addresses in the node page
+ */
+void set_data_blkaddr(struct dnode_of_data *dn)
+{
+	struct f2fs_node *rn;
+	__le32 *addr_array;
+	struct page *node_page = dn->node_page;
+	unsigned int ofs_in_node = dn->ofs_in_node;
+
+	f2fs_wait_on_page_writeback(node_page, NODE);
+
+	rn = F2FS_NODE(node_page);
+
+	/* Get physical address of data block */
+	addr_array = blkaddr_in_node(rn);
+	addr_array[ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
+	set_page_dirty(node_page);
+}
+
+int reserve_new_block(struct dnode_of_data *dn)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+
+	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
+		return -EPERM;
+	if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
+		return -ENOSPC;
+
+	trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
+
+	dn->data_blkaddr = NEW_ADDR;
+	set_data_blkaddr(dn);
+	mark_inode_dirty(dn->inode);
+	sync_inode_page(dn);
+	return 0;
+}
+
+int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
+{
+	bool need_put = dn->inode_page ? false : true;
+	int err;
+
+	err = get_dnode_of_data(dn, index, ALLOC_NODE);
+	if (err)
+		return err;
+
+	if (dn->data_blkaddr == NULL_ADDR)
+		err = reserve_new_block(dn);
+	if (err || need_put)
+		f2fs_put_dnode(dn);
+	return err;
+}
+
+static void f2fs_map_bh(struct super_block *sb, pgoff_t pgofs,
+			struct extent_info *ei, struct buffer_head *bh_result)
+{
+	unsigned int blkbits = sb->s_blocksize_bits;
+	size_t max_size = bh_result->b_size;
+	size_t mapped_size;
+
+	clear_buffer_new(bh_result);
+	map_bh(bh_result, sb, ei->blk + pgofs - ei->fofs);
+	mapped_size = (ei->fofs + ei->len - pgofs) << blkbits;
+	bh_result->b_size = min(max_size, mapped_size);
+}
+
+static bool lookup_extent_info(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	pgoff_t start_fofs, end_fofs;
+	block_t start_blkaddr;
+
+	read_lock(&fi->ext_lock);
+	if (fi->ext.len == 0) {
+		read_unlock(&fi->ext_lock);
+		return false;
+	}
+
+	stat_inc_total_hit(inode->i_sb);
+
+	start_fofs = fi->ext.fofs;
+	end_fofs = fi->ext.fofs + fi->ext.len - 1;
+	start_blkaddr = fi->ext.blk;
+
+	if (pgofs >= start_fofs && pgofs <= end_fofs) {
+		*ei = fi->ext;
+		stat_inc_read_hit(inode->i_sb);
+		read_unlock(&fi->ext_lock);
+		return true;
+	}
+	read_unlock(&fi->ext_lock);
+	return false;
+}
+
+static bool update_extent_info(struct inode *inode, pgoff_t fofs,
+								block_t blkaddr)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	pgoff_t start_fofs, end_fofs;
+	block_t start_blkaddr, end_blkaddr;
+	int need_update = true;
+
+	write_lock(&fi->ext_lock);
+
+	start_fofs = fi->ext.fofs;
+	end_fofs = fi->ext.fofs + fi->ext.len - 1;
+	start_blkaddr = fi->ext.blk;
+	end_blkaddr = fi->ext.blk + fi->ext.len - 1;
+
+	/* Drop and initialize the matched extent */
+	if (fi->ext.len == 1 && fofs == start_fofs)
+		fi->ext.len = 0;
+
+	/* Initial extent */
+	if (fi->ext.len == 0) {
+		if (blkaddr != NULL_ADDR) {
+			fi->ext.fofs = fofs;
+			fi->ext.blk = blkaddr;
+			fi->ext.len = 1;
+		}
+		goto end_update;
+	}
+
+	/* Front merge */
+	if (fofs == start_fofs - 1 && blkaddr == start_blkaddr - 1) {
+		fi->ext.fofs--;
+		fi->ext.blk--;
+		fi->ext.len++;
+		goto end_update;
+	}
+
+	/* Back merge */
+	if (fofs == end_fofs + 1 && blkaddr == end_blkaddr + 1) {
+		fi->ext.len++;
+		goto end_update;
+	}
+
+	/* Split the existing extent */
+	if (fi->ext.len > 1 &&
+		fofs >= start_fofs && fofs <= end_fofs) {
+		if ((end_fofs - fofs) < (fi->ext.len >> 1)) {
+			fi->ext.len = fofs - start_fofs;
+		} else {
+			fi->ext.fofs = fofs + 1;
+			fi->ext.blk = start_blkaddr + fofs - start_fofs + 1;
+			fi->ext.len -= fofs - start_fofs + 1;
+		}
+	} else {
+		need_update = false;
+	}
+
+	/* Finally, if the extent is very fragmented, let's drop the cache. */
+	if (fi->ext.len < F2FS_MIN_EXTENT_LEN) {
+		fi->ext.len = 0;
+		set_inode_flag(fi, FI_NO_EXTENT);
+		need_update = true;
+	}
+end_update:
+	write_unlock(&fi->ext_lock);
+	return need_update;
+}
+
+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)
+{
+	struct extent_node *en;
+
+	en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
+	if (!en)
+		return NULL;
+
+	en->ei = *ei;
+	INIT_LIST_HEAD(&en->list);
+
+	rb_link_node(&en->rb_node, parent, p);
+	rb_insert_color(&en->rb_node, &et->root);
+	et->count++;
+	atomic_inc(&sbi->total_ext_node);
+	return en;
+}
+
+static void __detach_extent_node(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	rb_erase(&en->rb_node, &et->root);
+	et->count--;
+	atomic_dec(&sbi->total_ext_node);
+
+	if (et->cached_en == en)
+		et->cached_en = NULL;
+}
+
+static struct extent_tree *__find_extent_tree(struct f2fs_sb_info *sbi,
+							nid_t ino)
+{
+	struct extent_tree *et;
+
+	down_read(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
+	if (!et) {
+		up_read(&sbi->extent_tree_lock);
+		return NULL;
+	}
+	atomic_inc(&et->refcount);
+	up_read(&sbi->extent_tree_lock);
+
+	return et;
+}
+
+static struct extent_tree *__grab_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	nid_t ino = inode->i_ino;
+
+	down_write(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
+	if (!et) {
+		et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
+		f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
+		memset(et, 0, sizeof(struct extent_tree));
+		et->ino = ino;
+		et->root = RB_ROOT;
+		et->cached_en = NULL;
+		rwlock_init(&et->lock);
+		atomic_set(&et->refcount, 0);
+		et->count = 0;
+		sbi->total_ext_tree++;
+	}
+	atomic_inc(&et->refcount);
+	up_write(&sbi->extent_tree_lock);
+
+	return et;
+}
+
+static struct extent_node *__lookup_extent_tree(struct extent_tree *et,
+							unsigned int fofs)
+{
+	struct rb_node *node = et->root.rb_node;
+	struct extent_node *en;
+
+	if (et->cached_en) {
+		struct extent_info *cei = &et->cached_en->ei;
+
+		if (cei->fofs <= fofs && cei->fofs + cei->len > fofs)
+			return et->cached_en;
+	}
+
+	while (node) {
+		en = rb_entry(node, struct extent_node, rb_node);
+
+		if (fofs < en->ei.fofs) {
+			node = node->rb_left;
+		} else if (fofs >= en->ei.fofs + en->ei.len) {
+			node = node->rb_right;
+		} else {
+			et->cached_en = en;
+			return en;
+		}
+	}
+	return NULL;
+}
+
+static struct extent_node *__try_back_merge(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	struct extent_node *prev;
+	struct rb_node *node;
+
+	node = rb_prev(&en->rb_node);
+	if (!node)
+		return NULL;
+
+	prev = rb_entry(node, struct extent_node, rb_node);
+	if (__is_back_mergeable(&en->ei, &prev->ei)) {
+		en->ei.fofs = prev->ei.fofs;
+		en->ei.blk = prev->ei.blk;
+		en->ei.len += prev->ei.len;
+		__detach_extent_node(sbi, et, prev);
+		return prev;
+	}
+	return NULL;
+}
+
+static struct extent_node *__try_front_merge(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_node *en)
+{
+	struct extent_node *next;
+	struct rb_node *node;
+
+	node = rb_next(&en->rb_node);
+	if (!node)
+		return NULL;
+
+	next = rb_entry(node, struct extent_node, rb_node);
+	if (__is_front_mergeable(&en->ei, &next->ei)) {
+		en->ei.len += next->ei.len;
+		__detach_extent_node(sbi, et, next);
+		return next;
+	}
+	return NULL;
+}
+
+static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
+				struct extent_tree *et, struct extent_info *ei,
+				struct extent_node **den)
+{
+	struct rb_node **p = &et->root.rb_node;
+	struct rb_node *parent = NULL;
+	struct extent_node *en;
+
+	while (*p) {
+		parent = *p;
+		en = rb_entry(parent, struct extent_node, rb_node);
+
+		if (ei->fofs < en->ei.fofs) {
+			if (__is_front_mergeable(ei, &en->ei)) {
+				f2fs_bug_on(sbi, !den);
+				en->ei.fofs = ei->fofs;
+				en->ei.blk = ei->blk;
+				en->ei.len += ei->len;
+				*den = __try_back_merge(sbi, et, en);
+				return en;
+			}
+			p = &(*p)->rb_left;
+		} else if (ei->fofs >= en->ei.fofs + en->ei.len) {
+			if (__is_back_mergeable(ei, &en->ei)) {
+				f2fs_bug_on(sbi, !den);
+				en->ei.len += ei->len;
+				*den = __try_front_merge(sbi, et, en);
+				return en;
+			}
+			p = &(*p)->rb_right;
+		} else {
+			f2fs_bug_on(sbi, 1);
+		}
+	}
+
+	return __attach_extent_node(sbi, et, ei, parent, p);
+}
+
+static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
+					struct extent_tree *et, bool free_all)
+{
+	struct rb_node *node, *next;
+	struct extent_node *en;
+	unsigned int count = et->count;
+
+	node = rb_first(&et->root);
+	while (node) {
+		next = rb_next(node);
+		en = rb_entry(node, struct extent_node, rb_node);
+
+		if (free_all) {
+			spin_lock(&sbi->extent_lock);
+			if (!list_empty(&en->list))
+				list_del_init(&en->list);
+			spin_unlock(&sbi->extent_lock);
+		}
+
+		if (free_all || list_empty(&en->list)) {
+			__detach_extent_node(sbi, et, en);
+			kmem_cache_free(extent_node_slab, en);
+		}
+		node = next;
+	}
+
+	return count - et->count;
+}
+
+static void f2fs_init_extent_tree(struct inode *inode,
+						struct f2fs_extent *i_ext)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en;
+	struct extent_info ei;
+
+	if (le32_to_cpu(i_ext->len) < F2FS_MIN_EXTENT_LEN)
+		return;
+
+	et = __grab_extent_tree(inode);
+
+	write_lock(&et->lock);
+	if (et->count)
+		goto out;
+
+	set_extent_info(&ei, le32_to_cpu(i_ext->fofs),
+		le32_to_cpu(i_ext->blk), le32_to_cpu(i_ext->len));
+
+	en = __insert_extent_tree(sbi, et, &ei, NULL);
+	if (en) {
+		et->cached_en = en;
+
+		spin_lock(&sbi->extent_lock);
+		list_add_tail(&en->list, &sbi->extent_list);
+		spin_unlock(&sbi->extent_lock);
+	}
+out:
+	write_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+}
+
+static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en;
+
+	trace_f2fs_lookup_extent_tree_start(inode, pgofs);
+
+	et = __find_extent_tree(sbi, inode->i_ino);
+	if (!et)
+		return false;
+
+	read_lock(&et->lock);
+	en = __lookup_extent_tree(et, pgofs);
+	if (en) {
+		*ei = en->ei;
+		spin_lock(&sbi->extent_lock);
+		if (!list_empty(&en->list))
+			list_move_tail(&en->list, &sbi->extent_list);
+		spin_unlock(&sbi->extent_lock);
+		stat_inc_read_hit(sbi->sb);
+	}
+	stat_inc_total_hit(sbi->sb);
+	read_unlock(&et->lock);
+
+	trace_f2fs_lookup_extent_tree_end(inode, pgofs, en);
+
+	atomic_dec(&et->refcount);
+	return en ? true : false;
+}
+
+static void f2fs_update_extent_tree(struct inode *inode, pgoff_t fofs,
+							block_t blkaddr)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	struct extent_node *en = NULL, *en1 = NULL, *en2 = NULL, *en3 = NULL;
+	struct extent_node *den = NULL;
+	struct extent_info ei, dei;
+	unsigned int endofs;
+
+	trace_f2fs_update_extent_tree(inode, fofs, blkaddr);
+
+	et = __grab_extent_tree(inode);
+
+	write_lock(&et->lock);
+
+	/* 1. lookup and remove existing extent info in cache */
+	en = __lookup_extent_tree(et, fofs);
+	if (!en)
+		goto update_extent;
+
+	dei = en->ei;
+	__detach_extent_node(sbi, et, en);
+
+	/* 2. if extent can be split more, split and insert the left part */
+	if (dei.len > 1) {
+		/*  insert left part of split extent into cache */
+		if (fofs - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
+			set_extent_info(&ei, dei.fofs, dei.blk,
+							fofs - dei.fofs);
+			en1 = __insert_extent_tree(sbi, et, &ei, NULL);
+		}
+
+		/* insert right part of split extent into cache */
+		endofs = dei.fofs + dei.len - 1;
+		if (endofs - fofs >= F2FS_MIN_EXTENT_LEN) {
+			set_extent_info(&ei, fofs + 1,
+				fofs - dei.fofs + dei.blk, endofs - fofs);
+			en2 = __insert_extent_tree(sbi, et, &ei, NULL);
+		}
+	}
+
+update_extent:
+	/* 3. update extent in extent cache */
+	if (blkaddr) {
+		set_extent_info(&ei, fofs, blkaddr, 1);
+		en3 = __insert_extent_tree(sbi, et, &ei, &den);
+	}
+
+	/* 4. update in global extent list */
+	spin_lock(&sbi->extent_lock);
+	if (en && !list_empty(&en->list))
+		list_del(&en->list);
+	/*
+	 * en1 and en2 split from en, they will become more and more smaller
+	 * fragments after splitting several times. So if the length is smaller
+	 * than F2FS_MIN_EXTENT_LEN, we will not add them into extent tree.
+	 */
+	if (en1)
+		list_add_tail(&en1->list, &sbi->extent_list);
+	if (en2)
+		list_add_tail(&en2->list, &sbi->extent_list);
+	if (en3) {
+		if (list_empty(&en3->list))
+			list_add_tail(&en3->list, &sbi->extent_list);
+		else
+			list_move_tail(&en3->list, &sbi->extent_list);
+	}
+	if (den && !list_empty(&den->list))
+		list_del(&den->list);
+	spin_unlock(&sbi->extent_lock);
+
+	/* 5. release extent node */
+	if (en)
+		kmem_cache_free(extent_node_slab, en);
+	if (den)
+		kmem_cache_free(extent_node_slab, den);
+
+	write_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+}
+
+void f2fs_preserve_extent_tree(struct inode *inode)
+{
+	struct extent_tree *et;
+	struct extent_info *ext = &F2FS_I(inode)->ext;
+	bool sync = false;
+
+	if (!test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		return;
+
+	et = __find_extent_tree(F2FS_I_SB(inode), inode->i_ino);
+	if (!et) {
+		if (ext->len) {
+			ext->len = 0;
+			update_inode_page(inode);
+		}
+		return;
+	}
+
+	read_lock(&et->lock);
+	if (et->count) {
+		struct extent_node *en;
+
+		if (et->cached_en) {
+			en = et->cached_en;
+		} else {
+			struct rb_node *node = rb_first(&et->root);
+
+			if (!node)
+				node = rb_last(&et->root);
+			en = rb_entry(node, struct extent_node, rb_node);
+		}
+
+		if (__is_extent_same(ext, &en->ei))
+			goto out;
+
+		*ext = en->ei;
+		sync = true;
+	} else if (ext->len) {
+		ext->len = 0;
+		sync = true;
+	}
+out:
+	read_unlock(&et->lock);
+	atomic_dec(&et->refcount);
+
+	if (sync)
+		update_inode_page(inode);
+}
+
+void f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+	struct extent_tree *treevec[EXT_TREE_VEC_SIZE];
+	struct extent_node *en, *tmp;
+	unsigned long ino = F2FS_ROOT_INO(sbi);
+	struct radix_tree_iter iter;
+	void **slot;
+	unsigned int found;
+	unsigned int node_cnt = 0, tree_cnt = 0;
+
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return;
+
+	if (available_free_memory(sbi, EXTENT_CACHE))
+		return;
+
+	spin_lock(&sbi->extent_lock);
+	list_for_each_entry_safe(en, tmp, &sbi->extent_list, list) {
+		if (!nr_shrink--)
+			break;
+		list_del_init(&en->list);
+	}
+	spin_unlock(&sbi->extent_lock);
+
+	down_read(&sbi->extent_tree_lock);
+	while ((found = radix_tree_gang_lookup(&sbi->extent_tree_root,
+				(void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
+		unsigned i;
+
+		ino = treevec[found - 1]->ino + 1;
+		for (i = 0; i < found; i++) {
+			struct extent_tree *et = treevec[i];
+
+			atomic_inc(&et->refcount);
+			write_lock(&et->lock);
+			node_cnt += __free_extent_tree(sbi, et, false);
+			write_unlock(&et->lock);
+			atomic_dec(&et->refcount);
+		}
+	}
+	up_read(&sbi->extent_tree_lock);
+
+	down_write(&sbi->extent_tree_lock);
+	radix_tree_for_each_slot(slot, &sbi->extent_tree_root, &iter,
+							F2FS_ROOT_INO(sbi)) {
+		struct extent_tree *et = (struct extent_tree *)*slot;
+
+		if (!atomic_read(&et->refcount) && !et->count) {
+			radix_tree_delete(&sbi->extent_tree_root, et->ino);
+			kmem_cache_free(extent_tree_slab, et);
+			sbi->total_ext_tree--;
+			tree_cnt++;
+		}
+	}
+	up_write(&sbi->extent_tree_lock);
+
+	trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
+}
+
+void f2fs_destroy_extent_tree(struct inode *inode)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct extent_tree *et;
+	unsigned int node_cnt = 0;
+
+	if (!test_opt(sbi, EXTENT_CACHE))
+		return;
+
+	et = __find_extent_tree(sbi, inode->i_ino);
+	if (!et)
+		goto out;
+
+	/* free all extent info belong to this extent tree */
+	write_lock(&et->lock);
+	node_cnt = __free_extent_tree(sbi, et, true);
+	write_unlock(&et->lock);
+
+	atomic_dec(&et->refcount);
+
+	/* try to find and delete extent tree entry in radix tree */
+	down_write(&sbi->extent_tree_lock);
+	et = radix_tree_lookup(&sbi->extent_tree_root, inode->i_ino);
+	if (!et) {
+		up_write(&sbi->extent_tree_lock);
+		goto out;
+	}
+	f2fs_bug_on(sbi, atomic_read(&et->refcount) || et->count);
+	radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
+	kmem_cache_free(extent_tree_slab, et);
+	sbi->total_ext_tree--;
+	up_write(&sbi->extent_tree_lock);
+out:
+	trace_f2fs_destroy_extent_tree(inode, node_cnt);
+	return;
+}
+
+void f2fs_init_extent_cache(struct inode *inode, struct f2fs_extent *i_ext)
+{
+	if (test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		f2fs_init_extent_tree(inode, i_ext);
+
+	write_lock(&F2FS_I(inode)->ext_lock);
+	get_extent_info(&F2FS_I(inode)->ext, *i_ext);
+	write_unlock(&F2FS_I(inode)->ext_lock);
+}
+
+static bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
+							struct extent_info *ei)
+{
+	if (is_inode_flag_set(F2FS_I(inode), FI_NO_EXTENT))
+		return false;
+
+	if (test_opt(F2FS_I_SB(inode), EXTENT_CACHE))
+		return f2fs_lookup_extent_tree(inode, pgofs, ei);
+
+	return lookup_extent_info(inode, pgofs, ei);
+}
+
+void f2fs_update_extent_cache(struct dnode_of_data *dn)
+{
+	struct f2fs_inode_info *fi = F2FS_I(dn->inode);
+	pgoff_t fofs;
+
+	f2fs_bug_on(F2FS_I_SB(dn->inode), dn->data_blkaddr == NEW_ADDR);
+
+	if (is_inode_flag_set(fi, FI_NO_EXTENT))
+		return;
+
+	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
+							dn->ofs_in_node;
+
+	if (test_opt(F2FS_I_SB(dn->inode), EXTENT_CACHE))
+		return f2fs_update_extent_tree(dn->inode, fofs,
+							dn->data_blkaddr);
+
+	if (update_extent_info(dn->inode, fofs, dn->data_blkaddr))
+		sync_inode_page(dn);
+}
+
+struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct dnode_of_data dn;
+	struct page *page;
+	struct extent_info ei;
+	int err;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = sync ? READ_SYNC : READA,
+	};
+
+	/*
+	 * If sync is false, it needs to check its block allocation.
+	 * This is need and triggered by two flows:
+	 *   gc and truncate_partial_data_page.
+	 */
+	if (!sync)
+		goto search;
+
+	page = find_get_page(mapping, index);
+	if (page && PageUptodate(page))
+		return page;
+	f2fs_put_page(page, 0);
+search:
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+	if (err)
+		return ERR_PTR(err);
+	f2fs_put_dnode(&dn);
+
+	if (dn.data_blkaddr == NULL_ADDR)
+		return ERR_PTR(-ENOENT);
+
+	/* By fallocate(), there is no cached page, but with NEW_ADDR */
+	if (unlikely(dn.data_blkaddr == NEW_ADDR))
+		return ERR_PTR(-EINVAL);
+
+got_it:
+	page = grab_cache_page(mapping, index);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	if (PageUptodate(page)) {
+		unlock_page(page);
+		return page;
+	}
+
+	fio.blk_addr = dn.data_blkaddr;
+	err = f2fs_submit_page_bio(F2FS_I_SB(inode), page, &fio);
+	if (err)
+		return ERR_PTR(err);
+
+	if (sync) {
+		wait_on_page_locked(page);
+		if (unlikely(!PageUptodate(page))) {
+			f2fs_put_page(page, 0);
+			return ERR_PTR(-EIO);
+		}
+	}
+	return page;
+}
+
+/*
+ * If it tries to access a hole, return an error.
+ * Because, the callers, functions in dir.c and GC, should be able to know
+ * whether this page exists or not.
+ */
+struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct dnode_of_data dn;
+	struct page *page;
+	struct extent_info ei;
+	int err;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = READ_SYNC,
+	};
+repeat:
+	page = grab_cache_page(mapping, index);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+		dn.data_blkaddr = ei.blk + index - ei.fofs;
+		goto got_it;
+	}
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
+	if (err) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(err);
+	}
+	f2fs_put_dnode(&dn);
+
+	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(-ENOENT);
+	}
+
+got_it:
+	if (PageUptodate(page))
+		return page;
+
+	/*
+	 * A new dentry page is allocated but not able to be written, since its
+	 * new inode page couldn't be allocated due to -ENOSPC.
+	 * In such the case, its blkaddr can be remained as NEW_ADDR.
+	 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
+	 */
+	if (dn.data_blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+		SetPageUptodate(page);
+		return page;
+	}
+
+	fio.blk_addr = dn.data_blkaddr;
+	err = f2fs_submit_page_bio(F2FS_I_SB(inode), page, &fio);
+	if (err)
+		return ERR_PTR(err);
+
+	lock_page(page);
+	if (unlikely(!PageUptodate(page))) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(-EIO);
+	}
+	if (unlikely(page->mapping != mapping)) {
+		f2fs_put_page(page, 1);
+		goto repeat;
+	}
+	return page;
+}
+
+/*
+ * Caller ensures that this data page is never allocated.
+ * A new zero-filled data page is allocated in the page cache.
+ *
+ * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
+ * f2fs_unlock_op().
+ * Note that, ipage is set only by make_empty_dir.
+ */
+struct page *get_new_data_page(struct inode *inode,
+		struct page *ipage, pgoff_t index, bool new_i_size)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct page *page;
+	struct dnode_of_data dn;
+	int err;
+
+	set_new_dnode(&dn, inode, ipage, NULL, 0);
+	err = f2fs_reserve_block(&dn, index);
+	if (err)
+		return ERR_PTR(err);
+repeat:
+	page = grab_cache_page(mapping, index);
+	if (!page) {
+		err = -ENOMEM;
+		goto put_err;
+	}
+
+	if (PageUptodate(page))
+		return page;
+
+	if (dn.data_blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+		SetPageUptodate(page);
+	} else {
+		struct f2fs_io_info fio = {
+			.type = DATA,
+			.rw = READ_SYNC,
+			.blk_addr = dn.data_blkaddr,
+		};
+		err = f2fs_submit_page_bio(F2FS_I_SB(inode), page, &fio);
+		if (err)
+			goto put_err;
+
+		lock_page(page);
+		if (unlikely(!PageUptodate(page))) {
+			f2fs_put_page(page, 1);
+			err = -EIO;
+			goto put_err;
+		}
+		if (unlikely(page->mapping != mapping)) {
+			f2fs_put_page(page, 1);
+			goto repeat;
+		}
+	}
+
+	if (new_i_size &&
+		i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
+		i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT));
+		/* Only the directory inode sets new_i_size */
+		set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
+	}
+	return page;
+
+put_err:
+	f2fs_put_dnode(&dn);
+	return ERR_PTR(err);
+}
+
+static int __allocate_data_block(struct dnode_of_data *dn)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+	struct f2fs_inode_info *fi = F2FS_I(dn->inode);
+	struct f2fs_summary sum;
+	struct node_info ni;
+	int seg = CURSEG_WARM_DATA;
+	pgoff_t fofs;
+
+	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
+		return -EPERM;
+
+	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
+	if (dn->data_blkaddr == NEW_ADDR)
+		goto alloc;
+
+	if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
+		return -ENOSPC;
+
+alloc:
+	get_node_info(sbi, dn->nid, &ni);
+	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
+
+	if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
+		seg = CURSEG_DIRECT_IO;
+
+	allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
+								&sum, seg);
+
+	/* direct IO doesn't use extent cache to maximize the performance */
+	set_data_blkaddr(dn);
+
+	/* update i_size */
+	fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
+							dn->ofs_in_node;
+	if (i_size_read(dn->inode) < ((fofs + 1) << PAGE_CACHE_SHIFT))
+		i_size_write(dn->inode, ((fofs + 1) << PAGE_CACHE_SHIFT));
+
+	return 0;
+}
+
+static void __allocate_data_blocks(struct inode *inode, loff_t offset,
+							size_t count)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct dnode_of_data dn;
+	u64 start = F2FS_BYTES_TO_BLK(offset);
+	u64 len = F2FS_BYTES_TO_BLK(count);
+	bool allocated;
+	u64 end_offset;
+
+	while (len) {
+		f2fs_balance_fs(sbi);
+		f2fs_lock_op(sbi);
+
+		/* When reading holes, we need its node page */
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		if (get_dnode_of_data(&dn, start, ALLOC_NODE))
+			goto out;
+
+		allocated = false;
+		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+
+		while (dn.ofs_in_node < end_offset && len) {
+			block_t blkaddr;
+
+			blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
+			if (blkaddr == NULL_ADDR || blkaddr == NEW_ADDR) {
+				if (__allocate_data_block(&dn))
+					goto sync_out;
+				allocated = true;
+			}
+			len--;
+			start++;
+			dn.ofs_in_node++;
+		}
+
+		if (allocated)
+			sync_inode_page(&dn);
+
+		f2fs_put_dnode(&dn);
+		f2fs_unlock_op(sbi);
+	}
+	return;
+
+sync_out:
+	if (allocated)
+		sync_inode_page(&dn);
+	f2fs_put_dnode(&dn);
+out:
+	f2fs_unlock_op(sbi);
+	return;
+}
+
+/*
+ * get_data_block() now supported readahead/bmap/rw direct_IO with mapped bh.
+ * If original data blocks are allocated, then give them to blockdev.
+ * Otherwise,
+ *     a. preallocate requested block addresses
+ *     b. do not use extent cache for better performance
+ *     c. give the block addresses to blockdev
+ */
+static int __get_data_block(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create, bool fiemap)
+{
+	unsigned int blkbits = inode->i_sb->s_blocksize_bits;
+	unsigned maxblocks = bh_result->b_size >> blkbits;
+	struct dnode_of_data dn;
+	int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
+	pgoff_t pgofs, end_offset;
+	int err = 0, ofs = 1;
+	struct extent_info ei;
+	bool allocated = false;
+
+	/* Get the page offset from the block offset(iblock) */
+	pgofs =	(pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
+
+	if (f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
+		f2fs_map_bh(inode->i_sb, pgofs, &ei, bh_result);
+		goto out;
+	}
+
+	if (create)
+		f2fs_lock_op(F2FS_I_SB(inode));
+
+	/* When reading holes, we need its node page */
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, pgofs, mode);
+	if (err) {
+		if (err == -ENOENT)
+			err = 0;
+		goto unlock_out;
+	}
+	if (dn.data_blkaddr == NEW_ADDR && !fiemap)
+		goto put_out;
+
+	if (dn.data_blkaddr != NULL_ADDR) {
+		clear_buffer_new(bh_result);
+		map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
+	} else if (create) {
+		err = __allocate_data_block(&dn);
+		if (err)
+			goto put_out;
+		allocated = true;
+		set_buffer_new(bh_result);
+		map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
+	} else {
+		goto put_out;
+	}
+
+	end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+	bh_result->b_size = (((size_t)1) << blkbits);
+	dn.ofs_in_node++;
+	pgofs++;
+
+get_next:
+	if (dn.ofs_in_node >= end_offset) {
+		if (allocated)
+			sync_inode_page(&dn);
+		allocated = false;
+		f2fs_put_dnode(&dn);
+
+		set_new_dnode(&dn, inode, NULL, NULL, 0);
+		err = get_dnode_of_data(&dn, pgofs, mode);
+		if (err) {
+			if (err == -ENOENT)
+				err = 0;
+			goto unlock_out;
+		}
+		if (dn.data_blkaddr == NEW_ADDR && !fiemap)
+			goto put_out;
+
+		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
+	}
+
+	if (maxblocks > (bh_result->b_size >> blkbits)) {
+		block_t blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
+		if (blkaddr == NULL_ADDR && create) {
+			err = __allocate_data_block(&dn);
+			if (err)
+				goto sync_out;
+			allocated = true;
+			set_buffer_new(bh_result);
+			blkaddr = dn.data_blkaddr;
+		}
+		/* Give more consecutive addresses for the readahead */
+		if (blkaddr == (bh_result->b_blocknr + ofs)) {
+			ofs++;
+			dn.ofs_in_node++;
+			pgofs++;
+			bh_result->b_size += (((size_t)1) << blkbits);
+			goto get_next;
+		}
+	}
+sync_out:
+	if (allocated)
+		sync_inode_page(&dn);
+put_out:
+	f2fs_put_dnode(&dn);
+unlock_out:
+	if (create)
+		f2fs_unlock_op(F2FS_I_SB(inode));
+out:
+	trace_f2fs_get_data_block(inode, iblock, bh_result, err);
+	return err;
+}
+
+static int get_data_block(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create)
+{
+	return __get_data_block(inode, iblock, bh_result, create, false);
+}
+
+static int get_data_block_fiemap(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create)
+{
+	return __get_data_block(inode, iblock, bh_result, create, true);
+}
+
+int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+		u64 start, u64 len)
+{
+	return generic_block_fiemap(inode, fieinfo,
+				start, len, get_data_block_fiemap);
+}
+
+static int f2fs_read_data_page(struct file *file, struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	int ret = -EAGAIN;
+
+	trace_f2fs_readpage(page, DATA);
+
+	/* If the file has inline data, try to read it directly */
+	if (f2fs_has_inline_data(inode))
+		ret = f2fs_read_inline_data(inode, page);
+	if (ret == -EAGAIN)
+		ret = mpage_readpage(page, get_data_block);
+
+	return ret;
+}
+
+static int f2fs_read_data_pages(struct file *file,
+			struct address_space *mapping,
+			struct list_head *pages, unsigned nr_pages)
+{
+	struct inode *inode = file->f_mapping->host;
+
+	/* If the file has inline data, skip readpages */
+	if (f2fs_has_inline_data(inode))
+		return 0;
+
+	return mpage_readpages(mapping, pages, nr_pages, get_data_block);
+}
+
+int do_write_data_page(struct page *page, struct f2fs_io_info *fio)
+{
+	struct inode *inode = page->mapping->host;
+	struct dnode_of_data dn;
+	int err = 0;
+
+	set_new_dnode(&dn, inode, NULL, NULL, 0);
+	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
+	if (err)
+		return err;
+
+	fio->blk_addr = dn.data_blkaddr;
+
+	/* This page is already truncated */
+	if (fio->blk_addr == NULL_ADDR) {
+		ClearPageUptodate(page);
+		goto out_writepage;
+	}
+
+	set_page_writeback(page);
+
+	/*
+	 * If current allocation needs SSR,
+	 * it had better in-place writes for updated data.
+	 */
+	if (unlikely(fio->blk_addr != NEW_ADDR &&
+			!is_cold_data(page) &&
+			need_inplace_update(inode))) {
+		rewrite_data_page(page, fio);
+		set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
+		trace_f2fs_do_write_data_page(page, IPU);
+	} else {
+		write_data_page(page, &dn, fio);
+		set_data_blkaddr(&dn);
+		f2fs_update_extent_cache(&dn);
+		trace_f2fs_do_write_data_page(page, OPU);
+		set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
+		if (page->index == 0)
+			set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
+	}
+out_writepage:
+	f2fs_put_dnode(&dn);
+	return err;
+}
+
+static int f2fs_write_data_page(struct page *page,
+					struct writeback_control *wbc)
+{
+	struct inode *inode = page->mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	loff_t i_size = i_size_read(inode);
+	const pgoff_t end_index = ((unsigned long long) i_size)
+							>> PAGE_CACHE_SHIFT;
+	unsigned offset = 0;
+	bool need_balance_fs = false;
+	int err = 0;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
+	};
+
+	trace_f2fs_writepage(page, DATA);
+
+	if (page->index < end_index)
+		goto write;
+
+	/*
+	 * If the offset is out-of-range of file size,
+	 * this page does not have to be written to disk.
+	 */
+	offset = i_size & (PAGE_CACHE_SIZE - 1);
+	if ((page->index >= end_index + 1) || !offset)
+		goto out;
+
+	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
+write:
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto redirty_out;
+	if (f2fs_is_drop_cache(inode))
+		goto out;
+	if (f2fs_is_volatile_file(inode) && !wbc->for_reclaim &&
+			available_free_memory(sbi, BASE_CHECK))
+		goto redirty_out;
+
+	/* Dentry blocks are controlled by checkpoint */
+	if (S_ISDIR(inode->i_mode)) {
+		if (unlikely(f2fs_cp_error(sbi)))
+			goto redirty_out;
+		err = do_write_data_page(page, &fio);
+		goto done;
+	}
+
+	/* we should bypass data pages to proceed the kworkder jobs */
+	if (unlikely(f2fs_cp_error(sbi))) {
+		SetPageError(page);
+		goto out;
+	}
+
+	if (!wbc->for_reclaim)
+		need_balance_fs = true;
+	else if (has_not_enough_free_secs(sbi, 0))
+		goto redirty_out;
+
+	err = -EAGAIN;
+	f2fs_lock_op(sbi);
+	if (f2fs_has_inline_data(inode))
+		err = f2fs_write_inline_data(inode, page);
+	if (err == -EAGAIN)
+		err = do_write_data_page(page, &fio);
+	f2fs_unlock_op(sbi);
+done:
+	if (err && err != -ENOENT)
+		goto redirty_out;
+
+	clear_cold_data(page);
+out:
+	inode_dec_dirty_pages(inode);
+	if (err)
+		ClearPageUptodate(page);
+	unlock_page(page);
+	if (need_balance_fs)
+		f2fs_balance_fs(sbi);
+	if (wbc->for_reclaim)
+		f2fs_submit_merged_bio(sbi, DATA, WRITE);
+	return 0;
+
+redirty_out:
+	redirty_page_for_writepage(wbc, page);
+	return AOP_WRITEPAGE_ACTIVATE;
+}
+
+static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
+			void *data)
+{
+	struct address_space *mapping = data;
+	int ret = mapping->a_ops->writepage(page, wbc);
+	mapping_set_error(mapping, ret);
+	return ret;
+}
+
+static int f2fs_write_data_pages(struct address_space *mapping,
+			    struct writeback_control *wbc)
+{
+	struct inode *inode = mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	bool locked = false;
+	int ret;
+	long diff;
+
+	trace_f2fs_writepages(mapping->host, wbc, DATA);
+
+	/* deal with chardevs and other special file */
+	if (!mapping->a_ops->writepage)
+		return 0;
+
+	if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
+			get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
+			available_free_memory(sbi, DIRTY_DENTS))
+		goto skip_write;
+
+	/* during POR, we don't need to trigger writepage at all. */
+	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
+		goto skip_write;
+
+	diff = nr_pages_to_write(sbi, DATA, wbc);
+
+	if (!S_ISDIR(inode->i_mode)) {
+		mutex_lock(&sbi->writepages);
+		locked = true;
+	}
+	ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
+	if (locked)
+		mutex_unlock(&sbi->writepages);
+
+	f2fs_submit_merged_bio(sbi, DATA, WRITE);
+
+	remove_dirty_dir_inode(inode);
+
+	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
+	return ret;
+
+skip_write:
+	wbc->pages_skipped += get_dirty_pages(inode);
+	return 0;
+}
+
+static void f2fs_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	if (to > inode->i_size) {
+		truncate_pagecache(inode, inode->i_size);
+		truncate_blocks(inode, inode->i_size, true);
+	}
+}
+
+static int f2fs_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned flags,
+		struct page **pagep, void **fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct page *page, *ipage;
+	pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
+	struct dnode_of_data dn;
+	int err = 0;
+
+	trace_f2fs_write_begin(inode, pos, len, flags);
+
+	f2fs_balance_fs(sbi);
+
+	/*
+	 * We should check this at this moment to avoid deadlock on inode page
+	 * and #0 page. The locking rule for inline_data conversion should be:
+	 * lock_page(page #0) -> lock_page(inode_page)
+	 */
+	if (index != 0) {
+		err = f2fs_convert_inline_inode(inode);
+		if (err)
+			goto fail;
+	}
+repeat:
+	page = grab_cache_page_write_begin(mapping, index, flags);
+	if (!page) {
+		err = -ENOMEM;
+		goto fail;
+	}
+
+	*pagep = page;
+
+	f2fs_lock_op(sbi);
+
+	/* check inline_data */
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage)) {
+		err = PTR_ERR(ipage);
+		goto unlock_fail;
+	}
+
+	set_new_dnode(&dn, inode, ipage, ipage, 0);
+
+	if (f2fs_has_inline_data(inode)) {
+		if (pos + len <= MAX_INLINE_DATA) {
+			read_inline_data(page, ipage);
+			set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
+			sync_inode_page(&dn);
+			goto put_next;
+		}
+		err = f2fs_convert_inline_page(&dn, page);
+		if (err)
+			goto put_fail;
+	}
+	err = f2fs_reserve_block(&dn, index);
+	if (err)
+		goto put_fail;
+put_next:
+	f2fs_put_dnode(&dn);
+	f2fs_unlock_op(sbi);
+
+	if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
+		return 0;
+
+	f2fs_wait_on_page_writeback(page, DATA);
+
+	if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
+		unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+		unsigned end = start + len;
+
+		/* Reading beyond i_size is simple: memset to zero */
+		zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
+		goto out;
+	}
+
+	if (dn.data_blkaddr == NEW_ADDR) {
+		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+	} else {
+		struct f2fs_io_info fio = {
+			.type = DATA,
+			.rw = READ_SYNC,
+			.blk_addr = dn.data_blkaddr,
+		};
+		err = f2fs_submit_page_bio(sbi, page, &fio);
+		if (err)
+			goto fail;
+
+		lock_page(page);
+		if (unlikely(!PageUptodate(page))) {
+			f2fs_put_page(page, 1);
+			err = -EIO;
+			goto fail;
+		}
+		if (unlikely(page->mapping != mapping)) {
+			f2fs_put_page(page, 1);
+			goto repeat;
+		}
+	}
+out:
+	SetPageUptodate(page);
+	clear_cold_data(page);
+	return 0;
+
+put_fail:
+	f2fs_put_dnode(&dn);
+unlock_fail:
+	f2fs_unlock_op(sbi);
+	f2fs_put_page(page, 1);
+fail:
+	f2fs_write_failed(mapping, pos + len);
+	return err;
+}
+
+static int f2fs_write_end(struct file *file,
+			struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
+{
+	struct inode *inode = page->mapping->host;
+
+	trace_f2fs_write_end(inode, pos, len, copied);
+
+	set_page_dirty(page);
+
+	if (pos + copied > i_size_read(inode)) {
+		i_size_write(inode, pos + copied);
+		mark_inode_dirty(inode);
+		update_inode_page(inode);
+	}
+
+	f2fs_put_page(page, 1);
+	return copied;
+}
+
+static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
+			   loff_t offset)
+{
+	unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
+
+	if (iov_iter_rw(iter) == READ)
+		return 0;
+
+	if (offset & blocksize_mask)
+		return -EINVAL;
+
+	if (iov_iter_alignment(iter) & blocksize_mask)
+		return -EINVAL;
+
+	return 0;
+}
+
+static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
+			      loff_t offset)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	size_t count = iov_iter_count(iter);
+	int err;
+
+	/* we don't need to use inline_data strictly */
+	if (f2fs_has_inline_data(inode)) {
+		err = f2fs_convert_inline_inode(inode);
+		if (err)
+			return err;
+	}
+
+	if (check_direct_IO(inode, iter, offset))
+		return 0;
+
+	trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
+
+	if (iov_iter_rw(iter) == WRITE)
+		__allocate_data_blocks(inode, offset, count);
+
+	err = blockdev_direct_IO(iocb, inode, iter, offset, get_data_block);
+	if (err < 0 && iov_iter_rw(iter) == WRITE)
+		f2fs_write_failed(mapping, offset + count);
+
+	trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err);
+
+	return err;
+}
+
+void f2fs_invalidate_page(struct page *page, unsigned int offset,
+							unsigned int length)
+{
+	struct inode *inode = page->mapping->host;
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+
+	if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
+		(offset % PAGE_CACHE_SIZE || length != PAGE_CACHE_SIZE))
+		return;
+
+	if (PageDirty(page)) {
+		if (inode->i_ino == F2FS_META_INO(sbi))
+			dec_page_count(sbi, F2FS_DIRTY_META);
+		else if (inode->i_ino == F2FS_NODE_INO(sbi))
+			dec_page_count(sbi, F2FS_DIRTY_NODES);
+		else
+			inode_dec_dirty_pages(inode);
+	}
+	ClearPagePrivate(page);
+}
+
+int f2fs_release_page(struct page *page, gfp_t wait)
+{
+	/* If this is dirty page, keep PagePrivate */
+	if (PageDirty(page))
+		return 0;
+
+	ClearPagePrivate(page);
+	return 1;
+}
+
+static int f2fs_set_data_page_dirty(struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
+
+	trace_f2fs_set_page_dirty(page, DATA);
+
+	SetPageUptodate(page);
+
+	if (f2fs_is_atomic_file(inode)) {
+		register_inmem_page(inode, page);
+		return 1;
+	}
+
+	mark_inode_dirty(inode);
+
+	if (!PageDirty(page)) {
+		__set_page_dirty_nobuffers(page);
+		update_dirty_page(inode, page);
+		return 1;
+	}
+	return 0;
+}
+
+static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
+{
+	struct inode *inode = mapping->host;
+
+	/* we don't need to use inline_data strictly */
+	if (f2fs_has_inline_data(inode)) {
+		int err = f2fs_convert_inline_inode(inode);
+		if (err)
+			return err;
+	}
+	return generic_block_bmap(mapping, block, get_data_block);
+}
+
+void init_extent_cache_info(struct f2fs_sb_info *sbi)
+{
+	INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
+	init_rwsem(&sbi->extent_tree_lock);
+	INIT_LIST_HEAD(&sbi->extent_list);
+	spin_lock_init(&sbi->extent_lock);
+	sbi->total_ext_tree = 0;
+	atomic_set(&sbi->total_ext_node, 0);
+}
+
+int __init 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 destroy_extent_cache(void)
+{
+	kmem_cache_destroy(extent_node_slab);
+	kmem_cache_destroy(extent_tree_slab);
+}
+
+const struct address_space_operations f2fs_dblock_aops = {
+	.readpage	= f2fs_read_data_page,
+	.readpages	= f2fs_read_data_pages,
+	.writepage	= f2fs_write_data_page,
+	.writepages	= f2fs_write_data_pages,
+	.write_begin	= f2fs_write_begin,
+	.write_end	= f2fs_write_end,
+	.set_page_dirty	= f2fs_set_data_page_dirty,
+	.invalidatepage	= f2fs_invalidate_page,
+	.releasepage	= f2fs_release_page,
+	.direct_IO	= f2fs_direct_IO,
+	.bmap		= f2fs_bmap,
+};