diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index ed6a6ec..0dc8ee8 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -20,11 +20,73 @@
 #include "f2fs.h"
 #include "segment.h"
 #include "node.h"
+#include "trace.h"
 #include <trace/events/f2fs.h>
 
 #define __reverse_ffz(x) __reverse_ffs(~(x))
 
 static struct kmem_cache *discard_entry_slab;
+static struct kmem_cache *sit_entry_set_slab;
+static struct kmem_cache *inmem_entry_slab;
+
+/**
+ * Copied from latest lib/llist.c
+ * llist_for_each_entry_safe - iterate over some deleted entries of
+ *                             lock-less list of given type
+ *			       safe against removal of list entry
+ * @pos:	the type * to use as a loop cursor.
+ * @n:		another type * to use as temporary storage
+ * @node:	the first entry of deleted list entries.
+ * @member:	the name of the llist_node with the struct.
+ *
+ * In general, some entries of the lock-less list can be traversed
+ * safely only after being removed from list, so start with an entry
+ * instead of list head.
+ *
+ * If being used on entries deleted from lock-less list directly, the
+ * traverse order is from the newest to the oldest added entry.  If
+ * you want to traverse from the oldest to the newest, you must
+ * reverse the order by yourself before traversing.
+ */
+#define llist_for_each_entry_safe(pos, n, node, member)			       \
+	for (pos = llist_entry((node), typeof(*pos), member);		       \
+		&pos->member != NULL &&					       \
+		(n = llist_entry(pos->member.next, typeof(*n), member), true); \
+		pos = n)
+
+/**
+ * Copied from latest lib/llist.c
+ * llist_reverse_order - reverse order of a llist chain
+ * @head:	first item of the list to be reversed
+ *
+ * Reverse the order of a chain of llist entries and return the
+ * new first entry.
+ */
+struct llist_node *llist_reverse_order(struct llist_node *head)
+{
+	struct llist_node *new_head = NULL;
+
+	while (head) {
+		struct llist_node *tmp = head;
+		head = head->next;
+		tmp->next = new_head;
+		new_head = tmp;
+	}
+
+	return new_head;
+}
+
+/**
+ * Copied from latest linux/list.h
+ * list_last_entry - get the last element from a list
+ * @ptr:	the list head to take the element from.
+ * @type:	the type of the struct this is embedded in.
+ * @member:	the name of the list_struct within the struct.
+ *
+ * Note, that list is expected to be not empty.
+ */
+#define list_last_entry(ptr, type, member) \
+	list_entry((ptr)->prev, type, member)
 
 /*
  * __reverse_ffs is copied from include/asm-generic/bitops/__ffs.h since
@@ -172,6 +234,90 @@
 	return result + __reverse_ffz(tmp);
 }
 
+void register_inmem_page(struct inode *inode, struct page *page)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct inmem_pages *new;
+	int err;
+
+	SetPagePrivate(page);
+	f2fs_trace_pid(page);
+
+	new = f2fs_kmem_cache_alloc(inmem_entry_slab, GFP_NOFS);
+
+	/* add atomic page indices to the list */
+	new->page = page;
+	INIT_LIST_HEAD(&new->list);
+retry:
+	/* increase reference count with clean state */
+	mutex_lock(&fi->inmem_lock);
+	err = radix_tree_insert(&fi->inmem_root, page->index, new);
+	if (err == -EEXIST) {
+		mutex_unlock(&fi->inmem_lock);
+		kmem_cache_free(inmem_entry_slab, new);
+		return;
+	} else if (err) {
+		mutex_unlock(&fi->inmem_lock);
+		goto retry;
+	}
+	get_page(page);
+	list_add_tail(&new->list, &fi->inmem_pages);
+	inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
+	mutex_unlock(&fi->inmem_lock);
+}
+
+void commit_inmem_pages(struct inode *inode, bool abort)
+{
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct inmem_pages *cur, *tmp;
+	bool submit_bio = false;
+	struct f2fs_io_info fio = {
+		.type = DATA,
+		.rw = WRITE_SYNC | REQ_PRIO,
+	};
+
+	/*
+	 * The abort is true only when f2fs_evict_inode is called.
+	 * Basically, the f2fs_evict_inode doesn't produce any data writes, so
+	 * that we don't need to call f2fs_balance_fs.
+	 * Otherwise, f2fs_gc in f2fs_balance_fs can wait forever until this
+	 * inode becomes free by iget_locked in f2fs_iget.
+	 */
+	if (!abort) {
+		f2fs_balance_fs(sbi);
+		f2fs_lock_op(sbi);
+	}
+
+	mutex_lock(&fi->inmem_lock);
+	list_for_each_entry_safe(cur, tmp, &fi->inmem_pages, list) {
+		if (!abort) {
+			lock_page(cur->page);
+			if (cur->page->mapping == inode->i_mapping) {
+				f2fs_wait_on_page_writeback(cur->page, DATA);
+				if (clear_page_dirty_for_io(cur->page))
+					inode_dec_dirty_pages(inode);
+				do_write_data_page(cur->page, &fio);
+				submit_bio = true;
+			}
+			f2fs_put_page(cur->page, 1);
+		} else {
+			put_page(cur->page);
+		}
+		radix_tree_delete(&fi->inmem_root, cur->page->index);
+		list_del(&cur->list);
+		kmem_cache_free(inmem_entry_slab, cur);
+		dec_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
+	}
+	mutex_unlock(&fi->inmem_lock);
+
+	if (!abort) {
+		f2fs_unlock_op(sbi);
+		if (submit_bio)
+			f2fs_submit_merged_bio(sbi, DATA, WRITE);
+	}
+}
+
 /*
  * This function balances dirty node and dentry pages.
  * In addition, it controls garbage collection.
@@ -192,7 +338,8 @@
 {
 	/* check the # of cached NAT entries and prefree segments */
 	if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK) ||
-				excess_prefree_segs(sbi))
+			excess_prefree_segs(sbi) ||
+			!available_free_memory(sbi, INO_ENTRIES))
 		f2fs_sync_fs(sbi->sb, true);
 }
 
@@ -232,24 +379,20 @@
 	if (kthread_should_stop())
 		return 0;
 
-	spin_lock(&fcc->issue_lock);
-	if (fcc->issue_list) {
-		fcc->dispatch_list = fcc->issue_list;
-		fcc->issue_list = fcc->issue_tail = NULL;
-	}
-	spin_unlock(&fcc->issue_lock);
-
-	if (fcc->dispatch_list) {
+	if (!llist_empty(&fcc->issue_list)) {
 		struct bio *bio = bio_alloc(GFP_NOIO, 0);
 		struct flush_cmd *cmd, *next;
 		int ret;
 
+		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
+		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
+
 		bio->bi_bdev = sbi->sb->s_bdev;
 		ret = __submit_bio_wait(WRITE_FLUSH, bio);
 
-		for (cmd = fcc->dispatch_list; cmd; cmd = next) {
+		llist_for_each_entry_safe(cmd, next,
+					  fcc->dispatch_list, llnode) {
 			cmd->ret = ret;
-			next = cmd->next;
 			complete(&cmd->wait);
 		}
 		bio_put(bio);
@@ -257,7 +400,7 @@
 	}
 
 	wait_event_interruptible(*q,
-			kthread_should_stop() || fcc->issue_list);
+		kthread_should_stop() || !llist_empty(&fcc->issue_list));
 	goto repeat;
 }
 
@@ -276,15 +419,8 @@
 		return blkdev_issue_flush(sbi->sb->s_bdev, GFP_KERNEL, NULL);
 
 	init_completion(&cmd.wait);
-	cmd.next = NULL;
 
-	spin_lock(&fcc->issue_lock);
-	if (fcc->issue_list)
-		fcc->issue_tail->next = &cmd;
-	else
-		fcc->issue_list = &cmd;
-	fcc->issue_tail = &cmd;
-	spin_unlock(&fcc->issue_lock);
+	llist_add(&cmd.llnode, &fcc->issue_list);
 
 	if (!fcc->dispatch_list)
 		wake_up(&fcc->flush_wait_queue);
@@ -303,8 +439,8 @@
 	fcc = kzalloc(sizeof(struct flush_cmd_control), GFP_KERNEL);
 	if (!fcc)
 		return -ENOMEM;
-	spin_lock_init(&fcc->issue_lock);
 	init_waitqueue_head(&fcc->flush_wait_queue);
+	init_llist_head(&fcc->issue_list);
 	SM_I(sbi)->cmd_control_info = fcc;
 	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
 				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
@@ -344,6 +480,10 @@
 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
 		enum dirty_type t = sentry->type;
 
+		if (unlikely(t >= DIRTY)) {
+			f2fs_bug_on(sbi, 1);
+			return;
+		}
 		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
 			dirty_i->nr_dirty[t]++;
 	}
@@ -403,17 +543,14 @@
 static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
 				block_t blkstart, block_t blklen)
 {
-	sector_t start = SECTOR_FROM_BLOCK(sbi, blkstart);
-	sector_t len = SECTOR_FROM_BLOCK(sbi, blklen);
+	sector_t start = SECTOR_FROM_BLOCK(blkstart);
+	sector_t len = SECTOR_FROM_BLOCK(blklen);
 	trace_f2fs_issue_discard(sbi->sb, blkstart, blklen);
 	return blkdev_issue_discard(sbi->sb->s_bdev, start, len, GFP_NOFS, 0);
 }
 
-void discard_next_dnode(struct f2fs_sb_info *sbi)
+void discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
 {
-	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
-	block_t blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
-
 	if (f2fs_issue_discard(sbi, blkaddr, 1)) {
 		struct page *page = grab_meta_page(sbi, blkaddr);
 		/* zero-filled page */
@@ -422,44 +559,98 @@
 	}
 }
 
-static void add_discard_addrs(struct f2fs_sb_info *sbi,
-			unsigned int segno, struct seg_entry *se)
+static void __add_discard_entry(struct f2fs_sb_info *sbi,
+		struct cp_control *cpc, unsigned int start, unsigned int end)
 {
 	struct list_head *head = &SM_I(sbi)->discard_list;
-	struct discard_entry *new;
+	struct discard_entry *new, *last;
+
+	if (!list_empty(head)) {
+		last = list_last_entry(head, struct discard_entry, list);
+		if (START_BLOCK(sbi, cpc->trim_start) + start ==
+						last->blkaddr + last->len) {
+			last->len += end - start;
+			goto done;
+		}
+	}
+
+	new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
+	INIT_LIST_HEAD(&new->list);
+	new->blkaddr = START_BLOCK(sbi, cpc->trim_start) + start;
+	new->len = end - start;
+	list_add_tail(&new->list, head);
+done:
+	SM_I(sbi)->nr_discards += end - start;
+	cpc->trimmed += end - start;
+}
+
+static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
 	int max_blocks = sbi->blocks_per_seg;
+	struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
-	unsigned long dmap[entries];
+	unsigned long *dmap = SIT_I(sbi)->tmp_map;
 	unsigned int start = 0, end = -1;
+	bool force = (cpc->reason == CP_DISCARD);
 	int i;
 
-	if (!test_opt(sbi, DISCARD))
+	if (!force && (!test_opt(sbi, DISCARD) ||
+			SM_I(sbi)->nr_discards >= SM_I(sbi)->max_discards))
 		return;
 
+	if (force && !se->valid_blocks) {
+		struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+		/*
+		 * if this segment is registered in the prefree list, then
+		 * we should skip adding a discard candidate, and let the
+		 * checkpoint do that later.
+		 */
+		mutex_lock(&dirty_i->seglist_lock);
+		if (test_bit(cpc->trim_start, dirty_i->dirty_segmap[PRE])) {
+			mutex_unlock(&dirty_i->seglist_lock);
+			cpc->trimmed += sbi->blocks_per_seg;
+			return;
+		}
+		mutex_unlock(&dirty_i->seglist_lock);
+
+		__add_discard_entry(sbi, cpc, 0, sbi->blocks_per_seg);
+		return;
+	}
+
 	/* zero block will be discarded through the prefree list */
 	if (!se->valid_blocks || se->valid_blocks == max_blocks)
 		return;
 
 	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
 	for (i = 0; i < entries; i++)
-		dmap[i] = (cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
+		dmap[i] = force ? ~ckpt_map[i] :
+				(cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
 
-	while (SM_I(sbi)->nr_discards <= SM_I(sbi)->max_discards) {
+	while (force || SM_I(sbi)->nr_discards <= SM_I(sbi)->max_discards) {
 		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
 		if (start >= max_blocks)
 			break;
 
 		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
 
-		new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
-		INIT_LIST_HEAD(&new->list);
-		new->blkaddr = START_BLOCK(sbi, segno) + start;
-		new->len = end - start;
+		if (end - start < cpc->trim_minlen)
+			continue;
 
-		list_add_tail(&new->list, head);
-		SM_I(sbi)->nr_discards += end - start;
+		__add_discard_entry(sbi, cpc, start, end);
+	}
+}
+
+void release_discard_addrs(struct f2fs_sb_info *sbi)
+{
+	struct list_head *head = &(SM_I(sbi)->discard_list);
+	struct discard_entry *entry, *this;
+
+	/* drop caches */
+	list_for_each_entry_safe(entry, this, head, list) {
+		list_del(&entry->list);
+		kmem_cache_free(discard_entry_slab, entry);
 	}
 }
 
@@ -470,10 +661,9 @@
 {
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 	unsigned int segno;
-	unsigned int total_segs = TOTAL_SEGS(sbi);
 
 	mutex_lock(&dirty_i->seglist_lock);
-	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], total_segs)
+	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], MAIN_SEGS(sbi))
 		__set_test_and_free(sbi, segno);
 	mutex_unlock(&dirty_i->seglist_lock);
 }
@@ -484,17 +674,17 @@
 	struct discard_entry *entry, *this;
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
-	unsigned int total_segs = TOTAL_SEGS(sbi);
 	unsigned int start = 0, end = -1;
 
 	mutex_lock(&dirty_i->seglist_lock);
 
 	while (1) {
 		int i;
-		start = find_next_bit(prefree_map, total_segs, end + 1);
-		if (start >= total_segs)
+		start = find_next_bit(prefree_map, MAIN_SEGS(sbi), end + 1);
+		if (start >= MAIN_SEGS(sbi))
 			break;
-		end = find_next_zero_bit(prefree_map, total_segs, start + 1);
+		end = find_next_zero_bit(prefree_map, MAIN_SEGS(sbi),
+								start + 1);
 
 		for (i = start; i < end; i++)
 			clear_bit(i, prefree_map);
@@ -518,11 +708,16 @@
 	}
 }
 
-static void __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
+static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
 {
 	struct sit_info *sit_i = SIT_I(sbi);
-	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap))
+
+	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap)) {
 		sit_i->dirty_sentries++;
+		return false;
+	}
+
+	return true;
 }
 
 static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
@@ -546,7 +741,7 @@
 	new_vblocks = se->valid_blocks + del;
 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
 
-	f2fs_bug_on((new_vblocks >> (sizeof(unsigned short) << 3) ||
+	f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) ||
 				(new_vblocks > sbi->blocks_per_seg)));
 
 	se->valid_blocks = new_vblocks;
@@ -555,11 +750,11 @@
 
 	/* Update valid block bitmap */
 	if (del > 0) {
-		if (f2fs_set_bit(offset, se->cur_valid_map))
-			BUG();
+		if (f2fs_test_and_set_bit(offset, se->cur_valid_map))
+			f2fs_bug_on(sbi, 1);
 	} else {
-		if (!f2fs_clear_bit(offset, se->cur_valid_map))
-			BUG();
+		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map))
+			f2fs_bug_on(sbi, 1);
 	}
 	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
 		se->ckpt_valid_blocks += del;
@@ -588,7 +783,7 @@
 	unsigned int segno = GET_SEGNO(sbi, addr);
 	struct sit_info *sit_i = SIT_I(sbi);
 
-	f2fs_bug_on(addr == NULL_ADDR);
+	f2fs_bug_on(sbi, addr == NULL_ADDR);
 	if (addr == NEW_ADDR)
 		return;
 
@@ -618,7 +813,7 @@
 /*
  * Calculate the number of current summary pages for writing
  */
-int npages_for_summary_flush(struct f2fs_sb_info *sbi)
+int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
 {
 	int valid_sum_count = 0;
 	int i, sum_in_page;
@@ -626,8 +821,13 @@
 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
 		if (sbi->ckpt->alloc_type[i] == SSR)
 			valid_sum_count += sbi->blocks_per_seg;
-		else
-			valid_sum_count += curseg_blkoff(sbi, i);
+		else {
+			if (for_ra)
+				valid_sum_count += le16_to_cpu(
+					F2FS_CKPT(sbi)->cur_data_blkoff[i]);
+			else
+				valid_sum_count += curseg_blkoff(sbi, i);
+		}
 	}
 
 	sum_in_page = (PAGE_CACHE_SIZE - 2 * SUM_JOURNAL_SIZE -
@@ -664,7 +864,7 @@
 	unsigned int segno = curseg->segno + 1;
 	struct free_segmap_info *free_i = FREE_I(sbi);
 
-	if (segno < TOTAL_SEGS(sbi) && segno % sbi->segs_per_sec)
+	if (segno < MAIN_SEGS(sbi) && segno % sbi->segs_per_sec)
 		return !test_bit(segno, free_i->free_segmap);
 	return 0;
 }
@@ -678,7 +878,7 @@
 {
 	struct free_segmap_info *free_i = FREE_I(sbi);
 	unsigned int segno, secno, zoneno;
-	unsigned int total_zones = TOTAL_SECS(sbi) / sbi->secs_per_zone;
+	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
 	unsigned int hint = *newseg / sbi->segs_per_sec;
 	unsigned int old_zoneno = GET_ZONENO_FROM_SEGNO(sbi, *newseg);
 	unsigned int left_start = hint;
@@ -686,22 +886,22 @@
 	int go_left = 0;
 	int i;
 
-	write_lock(&free_i->segmap_lock);
+	spin_lock(&free_i->segmap_lock);
 
 	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
 		segno = find_next_zero_bit(free_i->free_segmap,
-					TOTAL_SEGS(sbi), *newseg + 1);
+					MAIN_SEGS(sbi), *newseg + 1);
 		if (segno - *newseg < sbi->segs_per_sec -
 					(*newseg % sbi->segs_per_sec))
 			goto got_it;
 	}
 find_other_zone:
-	secno = find_next_zero_bit(free_i->free_secmap, TOTAL_SECS(sbi), hint);
-	if (secno >= TOTAL_SECS(sbi)) {
+	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
+	if (secno >= MAIN_SECS(sbi)) {
 		if (dir == ALLOC_RIGHT) {
 			secno = find_next_zero_bit(free_i->free_secmap,
-							TOTAL_SECS(sbi), 0);
-			f2fs_bug_on(secno >= TOTAL_SECS(sbi));
+							MAIN_SECS(sbi), 0);
+			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
 		} else {
 			go_left = 1;
 			left_start = hint - 1;
@@ -716,8 +916,8 @@
 			continue;
 		}
 		left_start = find_next_zero_bit(free_i->free_secmap,
-							TOTAL_SECS(sbi), 0);
-		f2fs_bug_on(left_start >= TOTAL_SECS(sbi));
+							MAIN_SECS(sbi), 0);
+		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
 		break;
 	}
 	secno = left_start;
@@ -756,10 +956,10 @@
 	}
 got_it:
 	/* set it as dirty segment in free segmap */
-	f2fs_bug_on(test_bit(segno, free_i->free_segmap));
+	f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
 	__set_inuse(sbi, segno);
 	*newseg = segno;
-	write_unlock(&free_i->segmap_lock);
+	spin_unlock(&free_i->segmap_lock);
 }
 
 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
@@ -810,7 +1010,7 @@
 {
 	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
-	unsigned long target_map[entries];
+	unsigned long *target_map = SIT_I(sbi)->tmp_map;
 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
 	int i, pos;
@@ -910,24 +1110,66 @@
 	stat_inc_seg_type(sbi, curseg);
 }
 
+static void __allocate_new_segments(struct f2fs_sb_info *sbi, int type)
+{
+	struct curseg_info *curseg = CURSEG_I(sbi, type);
+	unsigned int old_segno;
+
+	old_segno = curseg->segno;
+	SIT_I(sbi)->s_ops->allocate_segment(sbi, type, true);
+	locate_dirty_segment(sbi, old_segno);
+}
+
 void allocate_new_segments(struct f2fs_sb_info *sbi)
 {
-	struct curseg_info *curseg;
-	unsigned int old_curseg;
 	int i;
 
-	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
-		curseg = CURSEG_I(sbi, i);
-		old_curseg = curseg->segno;
-		SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
-		locate_dirty_segment(sbi, old_curseg);
-	}
+	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++)
+		__allocate_new_segments(sbi, i);
 }
 
 static const struct segment_allocation default_salloc_ops = {
 	.allocate_segment = allocate_segment_by_default,
 };
 
+int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
+{
+	__u64 start = F2FS_BYTES_TO_BLK(range->start);
+	__u64 end = start + F2FS_BYTES_TO_BLK(range->len) - 1;
+	unsigned int start_segno, end_segno;
+	struct cp_control cpc;
+
+	if (range->minlen > SEGMENT_SIZE(sbi) || start >= MAX_BLKADDR(sbi) ||
+						range->len < sbi->blocksize)
+		return -EINVAL;
+
+	cpc.trimmed = 0;
+	if (end <= MAIN_BLKADDR(sbi))
+		goto out;
+
+	/* start/end segment number in main_area */
+	start_segno = (start <= MAIN_BLKADDR(sbi)) ? 0 : GET_SEGNO(sbi, start);
+	end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
+						GET_SEGNO(sbi, end);
+	cpc.reason = CP_DISCARD;
+	cpc.trim_minlen = F2FS_BYTES_TO_BLK(range->minlen);
+
+	/* do checkpoint to issue discard commands safely */
+	for (; start_segno <= end_segno; start_segno = cpc.trim_end + 1) {
+		cpc.trim_start = start_segno;
+		cpc.trim_end = min_t(unsigned int, rounddown(start_segno +
+				BATCHED_TRIM_SEGMENTS(sbi),
+				sbi->segs_per_sec) - 1, end_segno);
+
+		mutex_lock(&sbi->gc_mutex);
+		write_checkpoint(sbi, &cpc);
+		mutex_unlock(&sbi->gc_mutex);
+	}
+out:
+	range->len = F2FS_BLK_TO_BYTES(cpc.trimmed);
+	return 0;
+}
+
 static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
 {
 	struct curseg_info *curseg = CURSEG_I(sbi, type);
@@ -954,8 +1196,8 @@
 		else
 			return CURSEG_COLD_DATA;
 	} else {
-		if (IS_DNODE(page) && !is_cold_node(page))
-			return CURSEG_HOT_NODE;
+		if (IS_DNODE(page) && is_cold_node(page))
+			return CURSEG_WARM_NODE;
 		else
 			return CURSEG_COLD_NODE;
 	}
@@ -983,15 +1225,15 @@
 
 static int __get_segment_type(struct page *page, enum page_type p_type)
 {
-	struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
-	switch (sbi->active_logs) {
+	switch (F2FS_P_SB(page)->active_logs) {
 	case 2:
 		return __get_segment_type_2(page, p_type);
 	case 4:
 		return __get_segment_type_4(page, p_type);
 	}
 	/* NR_CURSEG_TYPE(6) logs by default */
-	f2fs_bug_on(sbi->active_logs != NR_CURSEG_TYPE);
+	f2fs_bug_on(F2FS_P_SB(page),
+		F2FS_P_SB(page)->active_logs != NR_CURSEG_TYPE);
 	return __get_segment_type_6(page, p_type);
 }
 
@@ -1001,11 +1243,18 @@
 {
 	struct sit_info *sit_i = SIT_I(sbi);
 	struct curseg_info *curseg;
+	bool direct_io = (type == CURSEG_DIRECT_IO);
+
+	type = direct_io ? CURSEG_WARM_DATA : type;
 
 	curseg = CURSEG_I(sbi, type);
 
 	mutex_lock(&curseg->curseg_mutex);
 
+	/* direct_io'ed data is aligned to the segment for better performance */
+	if (direct_io && curseg->next_blkoff)
+		__allocate_new_segments(sbi, type);
+
 	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
 
 	/*
@@ -1037,57 +1286,55 @@
 }
 
 static void do_write_page(struct f2fs_sb_info *sbi, struct page *page,
-			block_t old_blkaddr, block_t *new_blkaddr,
-			struct f2fs_summary *sum, struct f2fs_io_info *fio)
+			struct f2fs_summary *sum,
+			struct f2fs_io_info *fio)
 {
 	int type = __get_segment_type(page, fio->type);
 
-	allocate_data_block(sbi, page, old_blkaddr, new_blkaddr, sum, type);
+	allocate_data_block(sbi, page, fio->blk_addr, &fio->blk_addr, sum, type);
 
 	/* writeout dirty page into bdev */
-	f2fs_submit_page_mbio(sbi, page, *new_blkaddr, fio);
+	f2fs_submit_page_mbio(sbi, page, fio);
 }
 
 void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
 {
 	struct f2fs_io_info fio = {
 		.type = META,
-		.rw = WRITE_SYNC | REQ_META | REQ_PRIO
+		.rw = WRITE_SYNC | REQ_META | REQ_PRIO,
+		.blk_addr = page->index,
 	};
 
 	set_page_writeback(page);
-	f2fs_submit_page_mbio(sbi, page, page->index, &fio);
+	f2fs_submit_page_mbio(sbi, page, &fio);
 }
 
 void write_node_page(struct f2fs_sb_info *sbi, struct page *page,
-		struct f2fs_io_info *fio,
-		unsigned int nid, block_t old_blkaddr, block_t *new_blkaddr)
+			unsigned int nid, struct f2fs_io_info *fio)
 {
 	struct f2fs_summary sum;
 	set_summary(&sum, nid, 0, 0);
-	do_write_page(sbi, page, old_blkaddr, new_blkaddr, &sum, fio);
+	do_write_page(sbi, page, &sum, fio);
 }
 
 void write_data_page(struct page *page, struct dnode_of_data *dn,
-		block_t *new_blkaddr, struct f2fs_io_info *fio)
+				struct f2fs_io_info *fio)
 {
-	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 	struct f2fs_summary sum;
 	struct node_info ni;
 
-	f2fs_bug_on(dn->data_blkaddr == NULL_ADDR);
+	f2fs_bug_on(sbi, dn->data_blkaddr == NULL_ADDR);
 	get_node_info(sbi, dn->nid, &ni);
 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
-
-	do_write_page(sbi, page, dn->data_blkaddr, new_blkaddr, &sum, fio);
+	do_write_page(sbi, page, &sum, fio);
+	dn->data_blkaddr = fio->blk_addr;
 }
 
-void rewrite_data_page(struct page *page, block_t old_blkaddr,
-					struct f2fs_io_info *fio)
+void rewrite_data_page(struct page *page, struct f2fs_io_info *fio)
 {
-	struct inode *inode = page->mapping->host;
-	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
-	f2fs_submit_page_mbio(sbi, page, old_blkaddr, fio);
+	stat_inc_inplace_blocks(F2FS_P_SB(page));
+	f2fs_submit_page_mbio(F2FS_P_SB(page), page, fio);
 }
 
 void recover_data_page(struct f2fs_sb_info *sbi,
@@ -1160,8 +1407,9 @@
 void f2fs_wait_on_page_writeback(struct page *page,
 				enum page_type type)
 {
-	struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
 	if (PageWriteback(page)) {
+		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
+
 		if (is_merged_page(sbi, page, type))
 			f2fs_submit_merged_bio(sbi, type, WRITE);
 		wait_on_page_writeback(page);
@@ -1244,7 +1492,7 @@
 		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
 							CURSEG_HOT_DATA]);
-		if (is_set_ckpt_flags(ckpt, CP_UMOUNT_FLAG))
+		if (__exist_node_summaries(sbi))
 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
 		else
 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
@@ -1253,7 +1501,7 @@
 							CURSEG_HOT_NODE]);
 		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
 							CURSEG_HOT_NODE]);
-		if (is_set_ckpt_flags(ckpt, CP_UMOUNT_FLAG))
+		if (__exist_node_summaries(sbi))
 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
 							type - CURSEG_HOT_NODE);
 		else
@@ -1264,7 +1512,7 @@
 	sum = (struct f2fs_summary_block *)page_address(new);
 
 	if (IS_NODESEG(type)) {
-		if (is_set_ckpt_flags(ckpt, CP_UMOUNT_FLAG)) {
+		if (__exist_node_summaries(sbi)) {
 			struct f2fs_summary *ns = &sum->entries[0];
 			int i;
 			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
@@ -1301,12 +1549,22 @@
 	int err;
 
 	if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG)) {
+		int npages = npages_for_summary_flush(sbi, true);
+
+		if (npages >= 2)
+			ra_meta_pages(sbi, start_sum_block(sbi), npages,
+								META_CP);
+
 		/* restore for compacted data summary */
 		if (read_compacted_summaries(sbi))
 			return -EINVAL;
 		type = CURSEG_HOT_NODE;
 	}
 
+	if (__exist_node_summaries(sbi))
+		ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
+					NR_CURSEG_TYPE - type, META_CP);
+
 	for (; type <= CURSEG_COLD_NODE; type++) {
 		err = read_normal_summaries(sbi, type);
 		if (err)
@@ -1400,8 +1658,7 @@
 
 void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
 {
-	if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG))
-		write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
+	write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
 }
 
 int lookup_journal_in_cursum(struct f2fs_summary_block *sum, int type,
@@ -1429,17 +1686,7 @@
 static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
 					unsigned int segno)
 {
-	struct sit_info *sit_i = SIT_I(sbi);
-	unsigned int offset = SIT_BLOCK_OFFSET(sit_i, segno);
-	block_t blk_addr = sit_i->sit_base_addr + offset;
-
-	check_seg_range(sbi, segno);
-
-	/* calculate sit block address */
-	if (f2fs_test_bit(offset, sit_i->sit_bitmap))
-		blk_addr += sit_i->sit_blocks;
-
-	return get_meta_page(sbi, blk_addr);
+	return get_meta_page(sbi, current_sit_addr(sbi, segno));
 }
 
 static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
@@ -1456,7 +1703,7 @@
 	/* get current sit block page without lock */
 	src_page = get_meta_page(sbi, src_off);
 	dst_page = grab_meta_page(sbi, dst_off);
-	f2fs_bug_on(PageDirty(src_page));
+	f2fs_bug_on(sbi, PageDirty(src_page));
 
 	src_addr = page_address(src_page);
 	dst_addr = page_address(dst_page);
@@ -1470,101 +1717,192 @@
 	return dst_page;
 }
 
-static bool flush_sits_in_journal(struct f2fs_sb_info *sbi)
+static struct sit_entry_set *grab_sit_entry_set(void)
+{
+	struct sit_entry_set *ses =
+			f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_ATOMIC);
+
+	ses->entry_cnt = 0;
+	INIT_LIST_HEAD(&ses->set_list);
+	return ses;
+}
+
+static void release_sit_entry_set(struct sit_entry_set *ses)
+{
+	list_del(&ses->set_list);
+	kmem_cache_free(sit_entry_set_slab, ses);
+}
+
+static void adjust_sit_entry_set(struct sit_entry_set *ses,
+						struct list_head *head)
+{
+	struct sit_entry_set *next = ses;
+
+	if (list_is_last(&ses->set_list, head))
+		return;
+
+	list_for_each_entry_continue(next, head, set_list)
+		if (ses->entry_cnt <= next->entry_cnt)
+			break;
+
+	list_move_tail(&ses->set_list, &next->set_list);
+}
+
+static void add_sit_entry(unsigned int segno, struct list_head *head)
+{
+	struct sit_entry_set *ses;
+	unsigned int start_segno = START_SEGNO(segno);
+
+	list_for_each_entry(ses, head, set_list) {
+		if (ses->start_segno == start_segno) {
+			ses->entry_cnt++;
+			adjust_sit_entry_set(ses, head);
+			return;
+		}
+	}
+
+	ses = grab_sit_entry_set();
+
+	ses->start_segno = start_segno;
+	ses->entry_cnt++;
+	list_add(&ses->set_list, head);
+}
+
+static void add_sits_in_set(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_sm_info *sm_info = SM_I(sbi);
+	struct list_head *set_list = &sm_info->sit_entry_set;
+	unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
+	unsigned int segno;
+
+	for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
+		add_sit_entry(segno, set_list);
+}
+
+static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
 {
 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
 	struct f2fs_summary_block *sum = curseg->sum_blk;
 	int i;
 
-	/*
-	 * If the journal area in the current summary is full of sit entries,
-	 * all the sit entries will be flushed. Otherwise the sit entries
-	 * are not able to replace with newly hot sit entries.
-	 */
-	if (sits_in_cursum(sum) >= SIT_JOURNAL_ENTRIES) {
-		for (i = sits_in_cursum(sum) - 1; i >= 0; i--) {
-			unsigned int segno;
-			segno = le32_to_cpu(segno_in_journal(sum, i));
-			__mark_sit_entry_dirty(sbi, segno);
-		}
-		update_sits_in_cursum(sum, -sits_in_cursum(sum));
-		return true;
+	for (i = sits_in_cursum(sum) - 1; i >= 0; i--) {
+		unsigned int segno;
+		bool dirtied;
+
+		segno = le32_to_cpu(segno_in_journal(sum, i));
+		dirtied = __mark_sit_entry_dirty(sbi, segno);
+
+		if (!dirtied)
+			add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
 	}
-	return false;
+	update_sits_in_cursum(sum, -sits_in_cursum(sum));
 }
 
 /*
  * CP calls this function, which flushes SIT entries including sit_journal,
  * and moves prefree segs to free segs.
  */
-void flush_sit_entries(struct f2fs_sb_info *sbi)
+void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 {
 	struct sit_info *sit_i = SIT_I(sbi);
 	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
 	struct f2fs_summary_block *sum = curseg->sum_blk;
-	unsigned long nsegs = TOTAL_SEGS(sbi);
-	struct page *page = NULL;
-	struct f2fs_sit_block *raw_sit = NULL;
-	unsigned int start = 0, end = 0;
-	unsigned int segno;
-	bool flushed;
+	struct sit_entry_set *ses, *tmp;
+	struct list_head *head = &SM_I(sbi)->sit_entry_set;
+	bool to_journal = true;
+	struct seg_entry *se;
 
 	mutex_lock(&curseg->curseg_mutex);
 	mutex_lock(&sit_i->sentry_lock);
 
 	/*
-	 * "flushed" indicates whether sit entries in journal are flushed
-	 * to the SIT area or not.
+	 * add and account sit entries of dirty bitmap in sit entry
+	 * set temporarily
 	 */
-	flushed = flush_sits_in_journal(sbi);
+	add_sits_in_set(sbi);
 
-	for_each_set_bit(segno, bitmap, nsegs) {
-		struct seg_entry *se = get_seg_entry(sbi, segno);
-		int sit_offset, offset;
+	/*
+	 * if there are no enough space in journal to store dirty sit
+	 * entries, remove all entries from journal and add and account
+	 * them in sit entry set.
+	 */
+	if (!__has_cursum_space(sum, sit_i->dirty_sentries, SIT_JOURNAL))
+		remove_sits_in_journal(sbi);
 
-		sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
+	if (!sit_i->dirty_sentries)
+		goto out;
 
-		/* add discard candidates */
-		if (SM_I(sbi)->nr_discards < SM_I(sbi)->max_discards)
-			add_discard_addrs(sbi, segno, se);
+	/*
+	 * there are two steps to flush sit entries:
+	 * #1, flush sit entries to journal in current cold data summary block.
+	 * #2, flush sit entries to sit page.
+	 */
+	list_for_each_entry_safe(ses, tmp, head, set_list) {
+		struct page *page = NULL;
+		struct f2fs_sit_block *raw_sit = NULL;
+		unsigned int start_segno = ses->start_segno;
+		unsigned int end = min(start_segno + SIT_ENTRY_PER_BLOCK,
+						(unsigned long)MAIN_SEGS(sbi));
+		unsigned int segno = start_segno;
 
-		if (flushed)
-			goto to_sit_page;
+		if (to_journal &&
+			!__has_cursum_space(sum, ses->entry_cnt, SIT_JOURNAL))
+			to_journal = false;
 
-		offset = lookup_journal_in_cursum(sum, SIT_JOURNAL, segno, 1);
-		if (offset >= 0) {
-			segno_in_journal(sum, offset) = cpu_to_le32(segno);
-			seg_info_to_raw_sit(se, &sit_in_journal(sum, offset));
-			goto flush_done;
-		}
-to_sit_page:
-		if (!page || (start > segno) || (segno > end)) {
-			if (page) {
-				f2fs_put_page(page, 1);
-				page = NULL;
-			}
-
-			start = START_SEGNO(sit_i, segno);
-			end = start + SIT_ENTRY_PER_BLOCK - 1;
-
-			/* read sit block that will be updated */
-			page = get_next_sit_page(sbi, start);
+		if (!to_journal) {
+			page = get_next_sit_page(sbi, start_segno);
 			raw_sit = page_address(page);
 		}
 
-		/* udpate entry in SIT block */
-		seg_info_to_raw_sit(se, &raw_sit->entries[sit_offset]);
-flush_done:
-		__clear_bit(segno, bitmap);
-		sit_i->dirty_sentries--;
+		/* flush dirty sit entries in region of current sit set */
+		for_each_set_bit_from(segno, bitmap, end) {
+			int offset, sit_offset;
+
+			se = get_seg_entry(sbi, segno);
+
+			/* add discard candidates */
+			if (cpc->reason != CP_DISCARD) {
+				cpc->trim_start = segno;
+				add_discard_addrs(sbi, cpc);
+			}
+
+			if (to_journal) {
+				offset = lookup_journal_in_cursum(sum,
+							SIT_JOURNAL, segno, 1);
+				f2fs_bug_on(sbi, offset < 0);
+				segno_in_journal(sum, offset) =
+							cpu_to_le32(segno);
+				seg_info_to_raw_sit(se,
+						&sit_in_journal(sum, offset));
+			} else {
+				sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
+				seg_info_to_raw_sit(se,
+						&raw_sit->entries[sit_offset]);
+			}
+
+			__clear_bit(segno, bitmap);
+			sit_i->dirty_sentries--;
+			ses->entry_cnt--;
+		}
+
+		if (!to_journal)
+			f2fs_put_page(page, 1);
+
+		f2fs_bug_on(sbi, ses->entry_cnt);
+		release_sit_entry_set(ses);
+	}
+
+	f2fs_bug_on(sbi, !list_empty(head));
+	f2fs_bug_on(sbi, sit_i->dirty_sentries);
+out:
+	if (cpc->reason == CP_DISCARD) {
+		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
+			add_discard_addrs(sbi, cpc);
 	}
 	mutex_unlock(&sit_i->sentry_lock);
 	mutex_unlock(&curseg->curseg_mutex);
 
-	/* writeout last modified SIT block */
-	f2fs_put_page(page, 1);
-
 	set_prefree_as_free_segments(sbi);
 }
 
@@ -1584,16 +1922,16 @@
 
 	SM_I(sbi)->sit_info = sit_i;
 
-	sit_i->sentries = vzalloc(TOTAL_SEGS(sbi) * sizeof(struct seg_entry));
+	sit_i->sentries = vzalloc(MAIN_SEGS(sbi) * sizeof(struct seg_entry));
 	if (!sit_i->sentries)
 		return -ENOMEM;
 
-	bitmap_size = f2fs_bitmap_size(TOTAL_SEGS(sbi));
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
 	sit_i->dirty_sentries_bitmap = kzalloc(bitmap_size, GFP_KERNEL);
 	if (!sit_i->dirty_sentries_bitmap)
 		return -ENOMEM;
 
-	for (start = 0; start < TOTAL_SEGS(sbi); start++) {
+	for (start = 0; start < MAIN_SEGS(sbi); start++) {
 		sit_i->sentries[start].cur_valid_map
 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
 		sit_i->sentries[start].ckpt_valid_map
@@ -1603,8 +1941,12 @@
 			return -ENOMEM;
 	}
 
+	sit_i->tmp_map = kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+	if (!sit_i->tmp_map)
+		return -ENOMEM;
+
 	if (sbi->segs_per_sec > 1) {
-		sit_i->sec_entries = vzalloc(TOTAL_SECS(sbi) *
+		sit_i->sec_entries = vzalloc(MAIN_SECS(sbi) *
 					sizeof(struct sec_entry));
 		if (!sit_i->sec_entries)
 			return -ENOMEM;
@@ -1639,7 +1981,6 @@
 
 static int build_free_segmap(struct f2fs_sb_info *sbi)
 {
-	struct f2fs_sm_info *sm_info = SM_I(sbi);
 	struct free_segmap_info *free_i;
 	unsigned int bitmap_size, sec_bitmap_size;
 
@@ -1650,12 +1991,12 @@
 
 	SM_I(sbi)->free_info = free_i;
 
-	bitmap_size = f2fs_bitmap_size(TOTAL_SEGS(sbi));
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
 	free_i->free_segmap = kmalloc(bitmap_size, GFP_KERNEL);
 	if (!free_i->free_segmap)
 		return -ENOMEM;
 
-	sec_bitmap_size = f2fs_bitmap_size(TOTAL_SECS(sbi));
+	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
 	free_i->free_secmap = kmalloc(sec_bitmap_size, GFP_KERNEL);
 	if (!free_i->free_secmap)
 		return -ENOMEM;
@@ -1665,11 +2006,10 @@
 	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
 
 	/* init free segmap information */
-	free_i->start_segno =
-		(unsigned int) GET_SEGNO_FROM_SEG0(sbi, sm_info->main_blkaddr);
+	free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi));
 	free_i->free_segments = 0;
 	free_i->free_sections = 0;
-	rwlock_init(&free_i->segmap_lock);
+	spin_lock_init(&free_i->segmap_lock);
 	return 0;
 }
 
@@ -1703,7 +2043,7 @@
 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
 	unsigned int i, start, end;
 	unsigned int readed, start_blk = 0;
-	int nrpages = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
+	int nrpages = MAX_BIO_BLOCKS(sbi);
 
 	do {
 		readed = ra_meta_pages(sbi, start_blk, nrpages, META_SIT);
@@ -1711,7 +2051,7 @@
 		start = start_blk * sit_i->sents_per_block;
 		end = (start_blk + readed) * sit_i->sents_per_block;
 
-		for (; start < end && start < TOTAL_SEGS(sbi); start++) {
+		for (; start < end && start < MAIN_SEGS(sbi); start++) {
 			struct seg_entry *se = &sit_i->sentries[start];
 			struct f2fs_sit_block *sit_blk;
 			struct f2fs_sit_entry sit;
@@ -1749,7 +2089,7 @@
 	unsigned int start;
 	int type;
 
-	for (start = 0; start < TOTAL_SEGS(sbi); start++) {
+	for (start = 0; start < MAIN_SEGS(sbi); start++) {
 		struct seg_entry *sentry = get_seg_entry(sbi, start);
 		if (!sentry->valid_blocks)
 			__set_free(sbi, start);
@@ -1766,18 +2106,22 @@
 {
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 	struct free_segmap_info *free_i = FREE_I(sbi);
-	unsigned int segno = 0, offset = 0, total_segs = TOTAL_SEGS(sbi);
+	unsigned int segno = 0, offset = 0;
 	unsigned short valid_blocks;
 
 	while (1) {
 		/* find dirty segment based on free segmap */
-		segno = find_next_inuse(free_i, total_segs, offset);
-		if (segno >= total_segs)
+		segno = find_next_inuse(free_i, MAIN_SEGS(sbi), offset);
+		if (segno >= MAIN_SEGS(sbi))
 			break;
 		offset = segno + 1;
 		valid_blocks = get_valid_blocks(sbi, segno, 0);
-		if (valid_blocks >= sbi->blocks_per_seg || !valid_blocks)
+		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
 			continue;
+		if (valid_blocks > sbi->blocks_per_seg) {
+			f2fs_bug_on(sbi, 1);
+			continue;
+		}
 		mutex_lock(&dirty_i->seglist_lock);
 		__locate_dirty_segment(sbi, segno, DIRTY);
 		mutex_unlock(&dirty_i->seglist_lock);
@@ -1787,7 +2131,7 @@
 static int init_victim_secmap(struct f2fs_sb_info *sbi)
 {
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
-	unsigned int bitmap_size = f2fs_bitmap_size(TOTAL_SECS(sbi));
+	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
 
 	dirty_i->victim_secmap = kzalloc(bitmap_size, GFP_KERNEL);
 	if (!dirty_i->victim_secmap)
@@ -1808,7 +2152,7 @@
 	SM_I(sbi)->dirty_info = dirty_i;
 	mutex_init(&dirty_i->seglist_lock);
 
-	bitmap_size = f2fs_bitmap_size(TOTAL_SEGS(sbi));
+	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
 
 	for (i = 0; i < NR_DIRTY_TYPE; i++) {
 		dirty_i->dirty_segmap[i] = kzalloc(bitmap_size, GFP_KERNEL);
@@ -1832,7 +2176,7 @@
 
 	sit_i->min_mtime = LLONG_MAX;
 
-	for (segno = 0; segno < TOTAL_SEGS(sbi); segno += sbi->segs_per_sec) {
+	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
 		unsigned int i;
 		unsigned long long mtime = 0;
 
@@ -1870,13 +2214,18 @@
 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
 	sm_info->rec_prefree_segments = sm_info->main_segments *
 					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
-	sm_info->ipu_policy = F2FS_IPU_DISABLE;
+	sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
+	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
 
 	INIT_LIST_HEAD(&sm_info->discard_list);
 	sm_info->nr_discards = 0;
 	sm_info->max_discards = 0;
 
+	sm_info->trim_sections = DEF_BATCHED_TRIM_SECTIONS;
+
+	INIT_LIST_HEAD(&sm_info->sit_entry_set);
+
 	if (test_opt(sbi, FLUSH_MERGE) && !f2fs_readonly(sbi->sb)) {
 		err = create_flush_cmd_control(sbi);
 		if (err)
@@ -1972,11 +2321,13 @@
 		return;
 
 	if (sit_i->sentries) {
-		for (start = 0; start < TOTAL_SEGS(sbi); start++) {
+		for (start = 0; start < MAIN_SEGS(sbi); start++) {
 			kfree(sit_i->sentries[start].cur_valid_map);
 			kfree(sit_i->sentries[start].ckpt_valid_map);
 		}
 	}
+	kfree(sit_i->tmp_map);
+
 	vfree(sit_i->sentries);
 	vfree(sit_i->sec_entries);
 	kfree(sit_i->dirty_sentries_bitmap);
@@ -2006,11 +2357,30 @@
 	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
 			sizeof(struct discard_entry));
 	if (!discard_entry_slab)
-		return -ENOMEM;
+		goto fail;
+
+	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
+			sizeof(struct sit_entry_set));
+	if (!sit_entry_set_slab)
+		goto destory_discard_entry;
+
+	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
+			sizeof(struct inmem_pages));
+	if (!inmem_entry_slab)
+		goto destroy_sit_entry_set;
 	return 0;
+
+destroy_sit_entry_set:
+	kmem_cache_destroy(sit_entry_set_slab);
+destory_discard_entry:
+	kmem_cache_destroy(discard_entry_slab);
+fail:
+	return -ENOMEM;
 }
 
 void destroy_segment_manager_caches(void)
 {
+	kmem_cache_destroy(sit_entry_set_slab);
 	kmem_cache_destroy(discard_entry_slab);
+	kmem_cache_destroy(inmem_entry_slab);
 }