1 files changed, 918 insertions, 255 deletions

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 0d8802453758..f964b68718c1 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -16,6 +16,7 @@
 #include <linux/kthread.h>
 #include <linux/swap.h>
 #include <linux/timer.h>
+#include <linux/freezer.h>
 
 #include "f2fs.h"
 #include "segment.h"
@@ -26,7 +27,7 @@
 #define __reverse_ffz(x) __reverse_ffs(~(x))
 
 static struct kmem_cache *discard_entry_slab;
-static struct kmem_cache *bio_entry_slab;
+static struct kmem_cache *discard_cmd_slab;
 static struct kmem_cache *sit_entry_set_slab;
 static struct kmem_cache *inmem_entry_slab;
 
@@ -242,11 +243,42 @@ void drop_inmem_pages(struct inode *inode)
 {
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 
+	mutex_lock(&fi->inmem_lock);
+	__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
+	mutex_unlock(&fi->inmem_lock);
+
 	clear_inode_flag(inode, FI_ATOMIC_FILE);
+	stat_dec_atomic_write(inode);
+}
+
+void drop_inmem_page(struct inode *inode, struct page *page)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+	struct list_head *head = &fi->inmem_pages;
+	struct inmem_pages *cur = NULL;
+
+	f2fs_bug_on(sbi, !IS_ATOMIC_WRITTEN_PAGE(page));
 
 	mutex_lock(&fi->inmem_lock);
-	__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
+	list_for_each_entry(cur, head, list) {
+		if (cur->page == page)
+			break;
+	}
+
+	f2fs_bug_on(sbi, !cur || cur->page != page);
+	list_del(&cur->list);
 	mutex_unlock(&fi->inmem_lock);
+
+	dec_page_count(sbi, F2FS_INMEM_PAGES);
+	kmem_cache_free(inmem_entry_slab, cur);
+
+	ClearPageUptodate(page);
+	set_page_private(page, 0);
+	ClearPagePrivate(page);
+	f2fs_put_page(page, 0);
+
+	trace_f2fs_commit_inmem_page(page, INMEM_INVALIDATE);
 }
 
 static int __commit_inmem_pages(struct inode *inode,
@@ -260,9 +292,8 @@ static int __commit_inmem_pages(struct inode *inode,
 		.type = DATA,
 		.op = REQ_OP_WRITE,
 		.op_flags = REQ_SYNC | REQ_PRIO,
-		.encrypted_page = NULL,
 	};
-	bool submit_bio = false;
+	pgoff_t last_idx = ULONG_MAX;
 	int err = 0;
 
 	list_for_each_entry_safe(cur, tmp, &fi->inmem_pages, list) {
@@ -280,6 +311,9 @@ static int __commit_inmem_pages(struct inode *inode,
 			}
 
 			fio.page = page;
+			fio.old_blkaddr = NULL_ADDR;
+			fio.encrypted_page = NULL;
+			fio.need_lock = LOCK_DONE;
 			err = do_write_data_page(&fio);
 			if (err) {
 				unlock_page(page);
@@ -288,15 +322,14 @@ static int __commit_inmem_pages(struct inode *inode,
 
 			/* record old blkaddr for revoking */
 			cur->old_addr = fio.old_blkaddr;
-
-			submit_bio = true;
+			last_idx = page->index;
 		}
 		unlock_page(page);
 		list_move_tail(&cur->list, revoke_list);
 	}
 
-	if (submit_bio)
-		f2fs_submit_merged_bio_cond(sbi, inode, NULL, 0, DATA, WRITE);
+	if (last_idx != ULONG_MAX)
+		f2fs_submit_merged_write_cond(sbi, inode, 0, last_idx, DATA);
 
 	if (!err)
 		__revoke_inmem_pages(inode, revoke_list, false, false);
@@ -315,6 +348,8 @@ int commit_inmem_pages(struct inode *inode)
 	f2fs_balance_fs(sbi, true);
 	f2fs_lock_op(sbi);
 
+	set_inode_flag(inode, FI_ATOMIC_COMMIT);
+
 	mutex_lock(&fi->inmem_lock);
 	err = __commit_inmem_pages(inode, &revoke_list);
 	if (err) {
@@ -336,6 +371,8 @@ int commit_inmem_pages(struct inode *inode)
 	}
 	mutex_unlock(&fi->inmem_lock);
 
+	clear_inode_flag(inode, FI_ATOMIC_COMMIT);
+
 	f2fs_unlock_op(sbi);
 	return err;
 }
@@ -347,15 +384,14 @@ int commit_inmem_pages(struct inode *inode)
 void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
 {
 #ifdef CONFIG_F2FS_FAULT_INJECTION
-	if (time_to_inject(sbi, FAULT_CHECKPOINT))
+	if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
+		f2fs_show_injection_info(FAULT_CHECKPOINT);
 		f2fs_stop_checkpoint(sbi, false);
+	}
 #endif
 
-	if (!need)
-		return;
-
 	/* balance_fs_bg is able to be pending */
-	if (excess_cached_nats(sbi))
+	if (need && excess_cached_nats(sbi))
 		f2fs_balance_fs_bg(sbi);
 
 	/*
@@ -364,7 +400,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
 	 */
 	if (has_not_enough_free_secs(sbi, 0, 0)) {
 		mutex_lock(&sbi->gc_mutex);
-		f2fs_gc(sbi, false, false);
+		f2fs_gc(sbi, false, false, NULL_SEGNO);
 	}
 }
 
@@ -381,9 +417,9 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
 	if (!available_free_memory(sbi, FREE_NIDS))
 		try_to_free_nids(sbi, MAX_FREE_NIDS);
 	else
-		build_free_nids(sbi, false);
+		build_free_nids(sbi, false, false);
 
-	if (!is_idle(sbi))
+	if (!is_idle(sbi) && !excess_dirty_nats(sbi))
 		return;
 
 	/* checkpoint is the only way to shrink partial cached entries */
@@ -404,29 +440,34 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
 	}
 }
 
-static int __submit_flush_wait(struct block_device *bdev)
+static int __submit_flush_wait(struct f2fs_sb_info *sbi,
+				struct block_device *bdev)
 {
 	struct bio *bio = f2fs_bio_alloc(0);
 	int ret;
 
-	bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
+	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
 	bio->bi_bdev = bdev;
 	ret = submit_bio_wait(bio);
 	bio_put(bio);
+
+	trace_f2fs_issue_flush(bdev, test_opt(sbi, NOBARRIER),
+				test_opt(sbi, FLUSH_MERGE), ret);
 	return ret;
 }
 
 static int submit_flush_wait(struct f2fs_sb_info *sbi)
 {
-	int ret = __submit_flush_wait(sbi->sb->s_bdev);
+	int ret = __submit_flush_wait(sbi, sbi->sb->s_bdev);
 	int i;
 
-	if (sbi->s_ndevs && !ret) {
-		for (i = 1; i < sbi->s_ndevs; i++) {
-			ret = __submit_flush_wait(FDEV(i).bdev);
-			if (ret)
-				break;
-		}
+	if (!sbi->s_ndevs || ret)
+		return ret;
+
+	for (i = 1; i < sbi->s_ndevs; i++) {
+		ret = __submit_flush_wait(sbi, FDEV(i).bdev);
+		if (ret)
+			break;
 	}
 	return ret;
 }
@@ -434,7 +475,7 @@ static int submit_flush_wait(struct f2fs_sb_info *sbi)
 static int issue_flush_thread(void *data)
 {
 	struct f2fs_sb_info *sbi = data;
-	struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
+	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
 	wait_queue_head_t *q = &fcc->flush_wait_queue;
 repeat:
 	if (kthread_should_stop())
@@ -448,6 +489,8 @@ repeat:
 		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
 
 		ret = submit_flush_wait(sbi);
+		atomic_inc(&fcc->issued_flush);
+
 		llist_for_each_entry_safe(cmd, next,
 					  fcc->dispatch_list, llnode) {
 			cmd->ret = ret;
@@ -463,27 +506,31 @@ repeat:
 
 int f2fs_issue_flush(struct f2fs_sb_info *sbi)
 {
-	struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
+	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
 	struct flush_cmd cmd;
-
-	trace_f2fs_issue_flush(sbi->sb, test_opt(sbi, NOBARRIER),
-					test_opt(sbi, FLUSH_MERGE));
+	int ret;
 
 	if (test_opt(sbi, NOBARRIER))
 		return 0;
 
-	if (!test_opt(sbi, FLUSH_MERGE) || !atomic_read(&fcc->submit_flush)) {
-		int ret;
+	if (!test_opt(sbi, FLUSH_MERGE)) {
+		ret = submit_flush_wait(sbi);
+		atomic_inc(&fcc->issued_flush);
+		return ret;
+	}
 
-		atomic_inc(&fcc->submit_flush);
+	if (!atomic_read(&fcc->issing_flush)) {
+		atomic_inc(&fcc->issing_flush);
 		ret = submit_flush_wait(sbi);
-		atomic_dec(&fcc->submit_flush);
+		atomic_dec(&fcc->issing_flush);
+
+		atomic_inc(&fcc->issued_flush);
 		return ret;
 	}
 
 	init_completion(&cmd.wait);
 
-	atomic_inc(&fcc->submit_flush);
+	atomic_inc(&fcc->issing_flush);
 	llist_add(&cmd.llnode, &fcc->issue_list);
 
 	if (!fcc->dispatch_list)
@@ -491,10 +538,10 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
 
 	if (fcc->f2fs_issue_flush) {
 		wait_for_completion(&cmd.wait);
-		atomic_dec(&fcc->submit_flush);
+		atomic_dec(&fcc->issing_flush);
 	} else {
 		llist_del_all(&fcc->issue_list);
-		atomic_set(&fcc->submit_flush, 0);
+		atomic_set(&fcc->issing_flush, 0);
 	}
 
 	return cmd.ret;
@@ -506,25 +553,31 @@ int create_flush_cmd_control(struct f2fs_sb_info *sbi)
 	struct flush_cmd_control *fcc;
 	int err = 0;
 
-	if (SM_I(sbi)->cmd_control_info) {
-		fcc = SM_I(sbi)->cmd_control_info;
+	if (SM_I(sbi)->fcc_info) {
+		fcc = SM_I(sbi)->fcc_info;
+		if (fcc->f2fs_issue_flush)
+			return err;
 		goto init_thread;
 	}
 
 	fcc = kzalloc(sizeof(struct flush_cmd_control), GFP_KERNEL);
 	if (!fcc)
 		return -ENOMEM;
-	atomic_set(&fcc->submit_flush, 0);
+	atomic_set(&fcc->issued_flush, 0);
+	atomic_set(&fcc->issing_flush, 0);
 	init_waitqueue_head(&fcc->flush_wait_queue);
 	init_llist_head(&fcc->issue_list);
-	SM_I(sbi)->cmd_control_info = fcc;
+	SM_I(sbi)->fcc_info = fcc;
+	if (!test_opt(sbi, FLUSH_MERGE))
+		return err;
+
 init_thread:
 	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
 				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
 	if (IS_ERR(fcc->f2fs_issue_flush)) {
 		err = PTR_ERR(fcc->f2fs_issue_flush);
 		kfree(fcc);
-		SM_I(sbi)->cmd_control_info = NULL;
+		SM_I(sbi)->fcc_info = NULL;
 		return err;
 	}
 
@@ -533,7 +586,7 @@ init_thread:
 
 void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free)
 {
-	struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
+	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
 
 	if (fcc && fcc->f2fs_issue_flush) {
 		struct task_struct *flush_thread = fcc->f2fs_issue_flush;
@@ -543,7 +596,7 @@ void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free)
 	}
 	if (free) {
 		kfree(fcc);
-		SM_I(sbi)->cmd_control_info = NULL;
+		SM_I(sbi)->fcc_info = NULL;
 	}
 }
 
@@ -587,8 +640,8 @@ static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
 		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
 			dirty_i->nr_dirty[t]--;
 
-		if (get_valid_blocks(sbi, segno, sbi->segs_per_sec) == 0)
-			clear_bit(GET_SECNO(sbi, segno),
+		if (get_valid_blocks(sbi, segno, true) == 0)
+			clear_bit(GET_SEC_FROM_SEG(sbi, segno),
 						dirty_i->victim_secmap);
 	}
 }
@@ -608,7 +661,7 @@ static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
 
 	mutex_lock(&dirty_i->seglist_lock);
 
-	valid_blocks = get_valid_blocks(sbi, segno, 0);
+	valid_blocks = get_valid_blocks(sbi, segno, false);
 
 	if (valid_blocks == 0) {
 		__locate_dirty_segment(sbi, segno, PRE);
@@ -623,104 +676,476 @@ static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
 	mutex_unlock(&dirty_i->seglist_lock);
 }
 
-static struct bio_entry *__add_bio_entry(struct f2fs_sb_info *sbi,
-							struct bio *bio)
+static struct discard_cmd *__create_discard_cmd(struct f2fs_sb_info *sbi,
+		struct block_device *bdev, block_t lstart,
+		block_t start, block_t len)
 {
-	struct list_head *wait_list = &(SM_I(sbi)->wait_list);
-	struct bio_entry *be = f2fs_kmem_cache_alloc(bio_entry_slab, GFP_NOFS);
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *pend_list;
+	struct discard_cmd *dc;
 
-	INIT_LIST_HEAD(&be->list);
-	be->bio = bio;
-	init_completion(&be->event);
-	list_add_tail(&be->list, wait_list);
+	f2fs_bug_on(sbi, !len);
 
-	return be;
+	pend_list = &dcc->pend_list[plist_idx(len)];
+
+	dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
+	INIT_LIST_HEAD(&dc->list);
+	dc->bdev = bdev;
+	dc->lstart = lstart;
+	dc->start = start;
+	dc->len = len;
+	dc->ref = 0;
+	dc->state = D_PREP;
+	dc->error = 0;
+	init_completion(&dc->wait);
+	list_add_tail(&dc->list, pend_list);
+	atomic_inc(&dcc->discard_cmd_cnt);
+	dcc->undiscard_blks += len;
+
+	return dc;
 }
 
-void f2fs_wait_all_discard_bio(struct f2fs_sb_info *sbi)
+static struct discard_cmd *__attach_discard_cmd(struct f2fs_sb_info *sbi,
+				struct block_device *bdev, block_t lstart,
+				block_t start, block_t len,
+				struct rb_node *parent, struct rb_node **p)
 {
-	struct list_head *wait_list = &(SM_I(sbi)->wait_list);
-	struct bio_entry *be, *tmp;
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_cmd *dc;
 
-	list_for_each_entry_safe(be, tmp, wait_list, list) {
-		struct bio *bio = be->bio;
-		int err;
+	dc = __create_discard_cmd(sbi, bdev, lstart, start, len);
 
-		wait_for_completion_io(&be->event);
-		err = be->error;
-		if (err == -EOPNOTSUPP)
-			err = 0;
+	rb_link_node(&dc->rb_node, parent, p);
+	rb_insert_color(&dc->rb_node, &dcc->root);
 
-		if (err)
-			f2fs_msg(sbi->sb, KERN_INFO,
-				"Issue discard failed, ret: %d", err);
+	return dc;
+}
 
-		bio_put(bio);
-		list_del(&be->list);
-		kmem_cache_free(bio_entry_slab, be);
-	}
+static void __detach_discard_cmd(struct discard_cmd_control *dcc,
+							struct discard_cmd *dc)
+{
+	if (dc->state == D_DONE)
+		atomic_dec(&dcc->issing_discard);
+
+	list_del(&dc->list);
+	rb_erase(&dc->rb_node, &dcc->root);
+	dcc->undiscard_blks -= dc->len;
+
+	kmem_cache_free(discard_cmd_slab, dc);
+
+	atomic_dec(&dcc->discard_cmd_cnt);
 }
 
-static void f2fs_submit_bio_wait_endio(struct bio *bio)
+static void __remove_discard_cmd(struct f2fs_sb_info *sbi,
+							struct discard_cmd *dc)
 {
-	struct bio_entry *be = (struct bio_entry *)bio->bi_private;
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+	f2fs_bug_on(sbi, dc->ref);
 
-	be->error = bio->bi_error;
-	complete(&be->event);
+	if (dc->error == -EOPNOTSUPP)
+		dc->error = 0;
+
+	if (dc->error)
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"Issue discard(%u, %u, %u) failed, ret: %d",
+			dc->lstart, dc->start, dc->len, dc->error);
+	__detach_discard_cmd(dcc, dc);
+}
+
+static void f2fs_submit_discard_endio(struct bio *bio)
+{
+	struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
+
+	dc->error = blk_status_to_errno(bio->bi_status);
+	dc->state = D_DONE;
+	complete_all(&dc->wait);
+	bio_put(bio);
+}
+
+void __check_sit_bitmap(struct f2fs_sb_info *sbi,
+				block_t start, block_t end)
+{
+#ifdef CONFIG_F2FS_CHECK_FS
+	struct seg_entry *sentry;
+	unsigned int segno;
+	block_t blk = start;
+	unsigned long offset, size, max_blocks = sbi->blocks_per_seg;
+	unsigned long *map;
+
+	while (blk < end) {
+		segno = GET_SEGNO(sbi, blk);
+		sentry = get_seg_entry(sbi, segno);
+		offset = GET_BLKOFF_FROM_SEG0(sbi, blk);
+
+		size = min((unsigned long)(end - blk), max_blocks);
+		map = (unsigned long *)(sentry->cur_valid_map);
+		offset = __find_rev_next_bit(map, size, offset);
+		f2fs_bug_on(sbi, offset != size);
+		blk += size;
+	}
+#endif
 }
 
 /* this function is copied from blkdev_issue_discard from block/blk-lib.c */
-static int __f2fs_issue_discard_async(struct f2fs_sb_info *sbi,
-		struct block_device *bdev, block_t blkstart, block_t blklen)
+static void __submit_discard_cmd(struct f2fs_sb_info *sbi,
+				struct discard_cmd *dc)
 {
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
 	struct bio *bio = NULL;
-	int err;
 
-	trace_f2fs_issue_discard(sbi->sb, blkstart, blklen);
+	if (dc->state != D_PREP)
+		return;
+
+	trace_f2fs_issue_discard(dc->bdev, dc->start, dc->len);
+
+	dc->error = __blkdev_issue_discard(dc->bdev,
+				SECTOR_FROM_BLOCK(dc->start),
+				SECTOR_FROM_BLOCK(dc->len),
+				GFP_NOFS, 0, &bio);
+	if (!dc->error) {
+		/* should keep before submission to avoid D_DONE right away */
+		dc->state = D_SUBMIT;
+		atomic_inc(&dcc->issued_discard);
+		atomic_inc(&dcc->issing_discard);
+		if (bio) {
+			bio->bi_private = dc;
+			bio->bi_end_io = f2fs_submit_discard_endio;
+			bio->bi_opf |= REQ_SYNC;
+			submit_bio(bio);
+			list_move_tail(&dc->list, &dcc->wait_list);
+			__check_sit_bitmap(sbi, dc->start, dc->start + dc->len);
+		}
+	} else {
+		__remove_discard_cmd(sbi, dc);
+	}
+}
+
+static struct discard_cmd *__insert_discard_tree(struct f2fs_sb_info *sbi,
+				struct block_device *bdev, block_t lstart,
+				block_t start, block_t len,
+				struct rb_node **insert_p,
+				struct rb_node *insert_parent)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct rb_node **p = &dcc->root.rb_node;
+	struct rb_node *parent = NULL;
+	struct discard_cmd *dc = NULL;
+
+	if (insert_p && insert_parent) {
+		parent = insert_parent;
+		p = insert_p;
+		goto do_insert;
+	}
+
+	p = __lookup_rb_tree_for_insert(sbi, &dcc->root, &parent, lstart);
+do_insert:
+	dc = __attach_discard_cmd(sbi, bdev, lstart, start, len, parent, p);
+	if (!dc)
+		return NULL;
+
+	return dc;
+}
+
+static void __relocate_discard_cmd(struct discard_cmd_control *dcc,
+						struct discard_cmd *dc)
+{
+	list_move_tail(&dc->list, &dcc->pend_list[plist_idx(dc->len)]);
+}
+
+static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
+				struct discard_cmd *dc, block_t blkaddr)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_info di = dc->di;
+	bool modified = false;
+
+	if (dc->state == D_DONE || dc->len == 1) {
+		__remove_discard_cmd(sbi, dc);
+		return;
+	}
+
+	dcc->undiscard_blks -= di.len;
+
+	if (blkaddr > di.lstart) {
+		dc->len = blkaddr - dc->lstart;
+		dcc->undiscard_blks += dc->len;
+		__relocate_discard_cmd(dcc, dc);
+		modified = true;
+	}
+
+	if (blkaddr < di.lstart + di.len - 1) {
+		if (modified) {
+			__insert_discard_tree(sbi, dc->bdev, blkaddr + 1,
+					di.start + blkaddr + 1 - di.lstart,
+					di.lstart + di.len - 1 - blkaddr,
+					NULL, NULL);
+		} else {
+			dc->lstart++;
+			dc->len--;
+			dc->start++;
+			dcc->undiscard_blks += dc->len;
+			__relocate_discard_cmd(dcc, dc);
+		}
+	}
+}
+
+static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
+				struct block_device *bdev, block_t lstart,
+				block_t start, block_t len)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_cmd *prev_dc = NULL, *next_dc = NULL;
+	struct discard_cmd *dc;
+	struct discard_info di = {0};
+	struct rb_node **insert_p = NULL, *insert_parent = NULL;
+	block_t end = lstart + len;
+
+	mutex_lock(&dcc->cmd_lock);
+
+	dc = (struct discard_cmd *)__lookup_rb_tree_ret(&dcc->root,
+					NULL, lstart,
+					(struct rb_entry **)&prev_dc,
+					(struct rb_entry **)&next_dc,
+					&insert_p, &insert_parent, true);
+	if (dc)
+		prev_dc = dc;
+
+	if (!prev_dc) {
+		di.lstart = lstart;
+		di.len = next_dc ? next_dc->lstart - lstart : len;
+		di.len = min(di.len, len);
+		di.start = start;
+	}
+
+	while (1) {
+		struct rb_node *node;
+		bool merged = false;
+		struct discard_cmd *tdc = NULL;
+
+		if (prev_dc) {
+			di.lstart = prev_dc->lstart + prev_dc->len;
+			if (di.lstart < lstart)
+				di.lstart = lstart;
+			if (di.lstart >= end)
+				break;
+
+			if (!next_dc || next_dc->lstart > end)
+				di.len = end - di.lstart;
+			else
+				di.len = next_dc->lstart - di.lstart;
+			di.start = start + di.lstart - lstart;
+		}
+
+		if (!di.len)
+			goto next;
+
+		if (prev_dc && prev_dc->state == D_PREP &&
+			prev_dc->bdev == bdev &&
+			__is_discard_back_mergeable(&di, &prev_dc->di)) {
+			prev_dc->di.len += di.len;
+			dcc->undiscard_blks += di.len;
+			__relocate_discard_cmd(dcc, prev_dc);
+			di = prev_dc->di;
+			tdc = prev_dc;
+			merged = true;
+		}
+
+		if (next_dc && next_dc->state == D_PREP &&
+			next_dc->bdev == bdev &&
+			__is_discard_front_mergeable(&di, &next_dc->di)) {
+			next_dc->di.lstart = di.lstart;
+			next_dc->di.len += di.len;
+			next_dc->di.start = di.start;
+			dcc->undiscard_blks += di.len;
+			__relocate_discard_cmd(dcc, next_dc);
+			if (tdc)
+				__remove_discard_cmd(sbi, tdc);
+			merged = true;
+		}
+
+		if (!merged) {
+			__insert_discard_tree(sbi, bdev, di.lstart, di.start,
+							di.len, NULL, NULL);
+		}
+ next:
+		prev_dc = next_dc;
+		if (!prev_dc)
+			break;
+
+		node = rb_next(&prev_dc->rb_node);
+		next_dc = rb_entry_safe(node, struct discard_cmd, rb_node);
+	}
+
+	mutex_unlock(&dcc->cmd_lock);
+}
+
+static int __queue_discard_cmd(struct f2fs_sb_info *sbi,
+		struct block_device *bdev, block_t blkstart, block_t blklen)
+{
+	block_t lblkstart = blkstart;
+
+	trace_f2fs_queue_discard(bdev, blkstart, blklen);
 
 	if (sbi->s_ndevs) {
 		int devi = f2fs_target_device_index(sbi, blkstart);
 
 		blkstart -= FDEV(devi).start_blk;
 	}
-	err = __blkdev_issue_discard(bdev,
-				SECTOR_FROM_BLOCK(blkstart),
-				SECTOR_FROM_BLOCK(blklen),
-				GFP_NOFS, 0, &bio);
-	if (!err && bio) {
-		struct bio_entry *be = __add_bio_entry(sbi, bio);
+	__update_discard_tree_range(sbi, bdev, lblkstart, blkstart, blklen);
+	return 0;
+}
+
+static void __issue_discard_cmd(struct f2fs_sb_info *sbi, bool issue_cond)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *pend_list;
+	struct discard_cmd *dc, *tmp;
+	struct blk_plug plug;
+	int i, iter = 0;
 
-		bio->bi_private = be;
-		bio->bi_end_io = f2fs_submit_bio_wait_endio;
-		bio->bi_opf |= REQ_SYNC;
-		submit_bio(bio);
+	mutex_lock(&dcc->cmd_lock);
+	f2fs_bug_on(sbi,
+		!__check_rb_tree_consistence(sbi, &dcc->root));
+	blk_start_plug(&plug);
+	for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
+		pend_list = &dcc->pend_list[i];
+		list_for_each_entry_safe(dc, tmp, pend_list, list) {
+			f2fs_bug_on(sbi, dc->state != D_PREP);
+
+			if (!issue_cond || is_idle(sbi))
+				__submit_discard_cmd(sbi, dc);
+			if (issue_cond && iter++ > DISCARD_ISSUE_RATE)
+				goto out;
+		}
 	}
+out:
+	blk_finish_plug(&plug);
+	mutex_unlock(&dcc->cmd_lock);
+}
 
-	return err;
+static void __wait_one_discard_bio(struct f2fs_sb_info *sbi,
+							struct discard_cmd *dc)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+	wait_for_completion_io(&dc->wait);
+	mutex_lock(&dcc->cmd_lock);
+	f2fs_bug_on(sbi, dc->state != D_DONE);
+	dc->ref--;
+	if (!dc->ref)
+		__remove_discard_cmd(sbi, dc);
+	mutex_unlock(&dcc->cmd_lock);
+}
+
+static void __wait_discard_cmd(struct f2fs_sb_info *sbi, bool wait_cond)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct list_head *wait_list = &(dcc->wait_list);
+	struct discard_cmd *dc, *tmp;
+	bool need_wait;
+
+next:
+	need_wait = false;
+
+	mutex_lock(&dcc->cmd_lock);
+	list_for_each_entry_safe(dc, tmp, wait_list, list) {
+		if (!wait_cond || (dc->state == D_DONE && !dc->ref)) {
+			wait_for_completion_io(&dc->wait);
+			__remove_discard_cmd(sbi, dc);
+		} else {
+			dc->ref++;
+			need_wait = true;
+			break;
+		}
+	}
+	mutex_unlock(&dcc->cmd_lock);
+
+	if (need_wait) {
+		__wait_one_discard_bio(sbi, dc);
+		goto next;
+	}
+}
+
+/* This should be covered by global mutex, &sit_i->sentry_lock */
+void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	struct discard_cmd *dc;
+	bool need_wait = false;
+
+	mutex_lock(&dcc->cmd_lock);
+	dc = (struct discard_cmd *)__lookup_rb_tree(&dcc->root, NULL, blkaddr);
+	if (dc) {
+		if (dc->state == D_PREP) {
+			__punch_discard_cmd(sbi, dc, blkaddr);
+		} else {
+			dc->ref++;
+			need_wait = true;
+		}
+	}
+	mutex_unlock(&dcc->cmd_lock);
+
+	if (need_wait)
+		__wait_one_discard_bio(sbi, dc);
+}
+
+void stop_discard_thread(struct f2fs_sb_info *sbi)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+	if (dcc && dcc->f2fs_issue_discard) {
+		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
+
+		dcc->f2fs_issue_discard = NULL;
+		kthread_stop(discard_thread);
+	}
+}
+
+/* This comes from f2fs_put_super */
+void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
+{
+	__issue_discard_cmd(sbi, false);
+	__wait_discard_cmd(sbi, false);
+}
+
+static int issue_discard_thread(void *data)
+{
+	struct f2fs_sb_info *sbi = data;
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+	wait_queue_head_t *q = &dcc->discard_wait_queue;
+
+	set_freezable();
+
+	do {
+		wait_event_interruptible(*q, kthread_should_stop() ||
+					freezing(current) ||
+					atomic_read(&dcc->discard_cmd_cnt));
+		if (try_to_freeze())
+			continue;
+		if (kthread_should_stop())
+			return 0;
+
+		__issue_discard_cmd(sbi, true);
+		__wait_discard_cmd(sbi, true);
+
+		congestion_wait(BLK_RW_SYNC, HZ/50);
+	} while (!kthread_should_stop());
+	return 0;
 }
 
 #ifdef CONFIG_BLK_DEV_ZONED
 static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
 		struct block_device *bdev, block_t blkstart, block_t blklen)
 {
-	sector_t nr_sects = SECTOR_FROM_BLOCK(blklen);
-	sector_t sector;
+	sector_t sector, nr_sects;
+	block_t lblkstart = blkstart;
 	int devi = 0;
 
 	if (sbi->s_ndevs) {
 		devi = f2fs_target_device_index(sbi, blkstart);
 		blkstart -= FDEV(devi).start_blk;
 	}
-	sector = SECTOR_FROM_BLOCK(blkstart);
-
-	if (sector & (bdev_zone_sectors(bdev) - 1) ||
-	    nr_sects != bdev_zone_sectors(bdev)) {
-		f2fs_msg(sbi->sb, KERN_INFO,
-			"(%d) %s: Unaligned discard attempted (block %x + %x)",
-			devi, sbi->s_ndevs ? FDEV(devi).path: "",
-			blkstart, blklen);
-		return -EIO;
-	}
 
 	/*
 	 * We need to know the type of the zone: for conventional zones,
@@ -732,10 +1157,21 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
 	case BLK_ZONE_TYPE_CONVENTIONAL:
 		if (!blk_queue_discard(bdev_get_queue(bdev)))
 			return 0;
-		return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
+		return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
 	case BLK_ZONE_TYPE_SEQWRITE_REQ:
 	case BLK_ZONE_TYPE_SEQWRITE_PREF:
-		trace_f2fs_issue_reset_zone(sbi->sb, blkstart);
+		sector = SECTOR_FROM_BLOCK(blkstart);
+		nr_sects = SECTOR_FROM_BLOCK(blklen);
+
+		if (sector & (bdev_zone_sectors(bdev) - 1) ||
+				nr_sects != bdev_zone_sectors(bdev)) {
+			f2fs_msg(sbi->sb, KERN_INFO,
+				"(%d) %s: Unaligned discard attempted (block %x + %x)",
+				devi, sbi->s_ndevs ? FDEV(devi).path: "",
+				blkstart, blklen);
+			return -EIO;
+		}
+		trace_f2fs_issue_reset_zone(bdev, blkstart);
 		return blkdev_reset_zones(bdev, sector,
 					  nr_sects, GFP_NOFS);
 	default:
@@ -753,7 +1189,7 @@ static int __issue_discard_async(struct f2fs_sb_info *sbi,
 				bdev_zoned_model(bdev) != BLK_ZONED_NONE)
 		return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen);
 #endif
-	return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
+	return __queue_discard_cmd(sbi, bdev, blkstart, blklen);
 }
 
 static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
@@ -796,32 +1232,8 @@ static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
 	return err;
 }
 
-static void __add_discard_entry(struct f2fs_sb_info *sbi,
-		struct cp_control *cpc, struct seg_entry *se,
-		unsigned int start, unsigned int end)
-{
-	struct list_head *head = &SM_I(sbi)->discard_list;
-	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;
-}
-
-static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc,
+							bool check_only)
 {
 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
 	int max_blocks = sbi->blocks_per_seg;
@@ -831,16 +1243,19 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	unsigned long *discard_map = (unsigned long *)se->discard_map;
 	unsigned long *dmap = SIT_I(sbi)->tmp_map;
 	unsigned int start = 0, end = -1;
-	bool force = (cpc->reason == CP_DISCARD);
+	bool force = (cpc->reason & CP_DISCARD);
+	struct discard_entry *de = NULL;
+	struct list_head *head = &SM_I(sbi)->dcc_info->entry_list;
 	int i;
 
 	if (se->valid_blocks == max_blocks || !f2fs_discard_en(sbi))
-		return;
+		return false;
 
 	if (!force) {
 		if (!test_opt(sbi, DISCARD) || !se->valid_blocks ||
-		    SM_I(sbi)->nr_discards >= SM_I(sbi)->max_discards)
-			return;
+			SM_I(sbi)->dcc_info->nr_discards >=
+				SM_I(sbi)->dcc_info->max_discards)
+			return false;
 	}
 
 	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
@@ -848,7 +1263,8 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 		dmap[i] = force ? ~ckpt_map[i] & ~discard_map[i] :
 				(cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
 
-	while (force || SM_I(sbi)->nr_discards <= SM_I(sbi)->max_discards) {
+	while (force || SM_I(sbi)->dcc_info->nr_discards <=
+				SM_I(sbi)->dcc_info->max_discards) {
 		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
 		if (start >= max_blocks)
 			break;
@@ -858,13 +1274,27 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 					&& (end - start) < cpc->trim_minlen)
 			continue;
 
-		__add_discard_entry(sbi, cpc, se, start, end);
+		if (check_only)
+			return true;
+
+		if (!de) {
+			de = f2fs_kmem_cache_alloc(discard_entry_slab,
+								GFP_F2FS_ZERO);
+			de->start_blkaddr = START_BLOCK(sbi, cpc->trim_start);
+			list_add_tail(&de->list, head);
+		}
+
+		for (i = start; i < end; i++)
+			__set_bit_le(i, (void *)de->discard_map);
+
+		SM_I(sbi)->dcc_info->nr_discards += end - start;
 	}
+	return false;
 }
 
 void release_discard_addrs(struct f2fs_sb_info *sbi)
 {
-	struct list_head *head = &(SM_I(sbi)->discard_list);
+	struct list_head *head = &(SM_I(sbi)->dcc_info->entry_list);
 	struct discard_entry *entry, *this;
 
 	/* drop caches */
@@ -890,16 +1320,13 @@ static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
 
 void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 {
-	struct list_head *head = &(SM_I(sbi)->discard_list);
+	struct list_head *head = &(SM_I(sbi)->dcc_info->entry_list);
 	struct discard_entry *entry, *this;
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
-	struct blk_plug plug;
 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
 	unsigned int start = 0, end = -1;
 	unsigned int secno, start_segno;
-	bool force = (cpc->reason == CP_DISCARD);
-
-	blk_start_plug(&plug);
+	bool force = (cpc->reason & CP_DISCARD);
 
 	mutex_lock(&dirty_i->seglist_lock);
 
@@ -916,41 +1343,126 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 
 		dirty_i->nr_dirty[PRE] -= end - start;
 
-		if (force || !test_opt(sbi, DISCARD))
+		if (!test_opt(sbi, DISCARD))
 			continue;
 
+		if (force && start >= cpc->trim_start &&
+					(end - 1) <= cpc->trim_end)
+				continue;
+
 		if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) {
 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
 				(end - start) << sbi->log_blocks_per_seg);
 			continue;
 		}
 next:
-		secno = GET_SECNO(sbi, start);
-		start_segno = secno * sbi->segs_per_sec;
+		secno = GET_SEC_FROM_SEG(sbi, start);
+		start_segno = GET_SEG_FROM_SEC(sbi, secno);
 		if (!IS_CURSEC(sbi, secno) &&
-			!get_valid_blocks(sbi, start, sbi->segs_per_sec))
+			!get_valid_blocks(sbi, start, true))
 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start_segno),
 				sbi->segs_per_sec << sbi->log_blocks_per_seg);
 
 		start = start_segno + sbi->segs_per_sec;
 		if (start < end)
 			goto next;
+		else
+			end = start - 1;
 	}
 	mutex_unlock(&dirty_i->seglist_lock);
 
 	/* send small discards */
 	list_for_each_entry_safe(entry, this, head, list) {
-		if (force && entry->len < cpc->trim_minlen)
-			goto skip;
-		f2fs_issue_discard(sbi, entry->blkaddr, entry->len);
-		cpc->trimmed += entry->len;
+		unsigned int cur_pos = 0, next_pos, len, total_len = 0;
+		bool is_valid = test_bit_le(0, entry->discard_map);
+
+find_next:
+		if (is_valid) {
+			next_pos = find_next_zero_bit_le(entry->discard_map,
+					sbi->blocks_per_seg, cur_pos);
+			len = next_pos - cur_pos;
+
+			if (f2fs_sb_mounted_blkzoned(sbi->sb) ||
+			    (force && len < cpc->trim_minlen))
+				goto skip;
+
+			f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos,
+									len);
+			cpc->trimmed += len;
+			total_len += len;
+		} else {
+			next_pos = find_next_bit_le(entry->discard_map,
+					sbi->blocks_per_seg, cur_pos);
+		}
 skip:
+		cur_pos = next_pos;
+		is_valid = !is_valid;
+
+		if (cur_pos < sbi->blocks_per_seg)
+			goto find_next;
+
 		list_del(&entry->list);
-		SM_I(sbi)->nr_discards -= entry->len;
+		SM_I(sbi)->dcc_info->nr_discards -= total_len;
 		kmem_cache_free(discard_entry_slab, entry);
 	}
 
-	blk_finish_plug(&plug);
+	wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
+}
+
+static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
+{
+	dev_t dev = sbi->sb->s_bdev->bd_dev;
+	struct discard_cmd_control *dcc;
+	int err = 0, i;
+
+	if (SM_I(sbi)->dcc_info) {
+		dcc = SM_I(sbi)->dcc_info;
+		goto init_thread;
+	}
+
+	dcc = kzalloc(sizeof(struct discard_cmd_control), GFP_KERNEL);
+	if (!dcc)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&dcc->entry_list);
+	for (i = 0; i < MAX_PLIST_NUM; i++)
+		INIT_LIST_HEAD(&dcc->pend_list[i]);
+	INIT_LIST_HEAD(&dcc->wait_list);
+	mutex_init(&dcc->cmd_lock);
+	atomic_set(&dcc->issued_discard, 0);
+	atomic_set(&dcc->issing_discard, 0);
+	atomic_set(&dcc->discard_cmd_cnt, 0);
+	dcc->nr_discards = 0;
+	dcc->max_discards = MAIN_SEGS(sbi) << sbi->log_blocks_per_seg;
+	dcc->undiscard_blks = 0;
+	dcc->root = RB_ROOT;
+
+	init_waitqueue_head(&dcc->discard_wait_queue);
+	SM_I(sbi)->dcc_info = dcc;
+init_thread:
+	dcc->f2fs_issue_discard = kthread_run(issue_discard_thread, sbi,
+				"f2fs_discard-%u:%u", MAJOR(dev), MINOR(dev));
+	if (IS_ERR(dcc->f2fs_issue_discard)) {
+		err = PTR_ERR(dcc->f2fs_issue_discard);
+		kfree(dcc);
+		SM_I(sbi)->dcc_info = NULL;
+		return err;
+	}
+
+	return err;
+}
+
+static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi)
+{
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+
+	if (!dcc)
+		return;
+
+	stop_discard_thread(sbi);
+
+	kfree(dcc);
+	SM_I(sbi)->dcc_info = NULL;
 }
 
 static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
@@ -995,14 +1507,38 @@ static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
 
 	/* Update valid block bitmap */
 	if (del > 0) {
-		if (f2fs_test_and_set_bit(offset, se->cur_valid_map))
+		if (f2fs_test_and_set_bit(offset, se->cur_valid_map)) {
+#ifdef CONFIG_F2FS_CHECK_FS
+			if (f2fs_test_and_set_bit(offset,
+						se->cur_valid_map_mir))
+				f2fs_bug_on(sbi, 1);
+			else
+				WARN_ON(1);
+#else
 			f2fs_bug_on(sbi, 1);
+#endif
+		}
 		if (f2fs_discard_en(sbi) &&
 			!f2fs_test_and_set_bit(offset, se->discard_map))
 			sbi->discard_blks--;
+
+		/* don't overwrite by SSR to keep node chain */
+		if (se->type == CURSEG_WARM_NODE) {
+			if (!f2fs_test_and_set_bit(offset, se->ckpt_valid_map))
+				se->ckpt_valid_blocks++;
+		}
 	} else {
-		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map))
+		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map)) {
+#ifdef CONFIG_F2FS_CHECK_FS
+			if (!f2fs_test_and_clear_bit(offset,
+						se->cur_valid_map_mir))
+				f2fs_bug_on(sbi, 1);
+			else
+				WARN_ON(1);
+#else
 			f2fs_bug_on(sbi, 1);
+#endif
+		}
 		if (f2fs_discard_en(sbi) &&
 			f2fs_test_and_clear_bit(offset, se->discard_map))
 			sbi->discard_blks++;
@@ -1188,8 +1724,8 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
 	struct free_segmap_info *free_i = FREE_I(sbi);
 	unsigned int segno, secno, zoneno;
 	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 hint = GET_SEC_FROM_SEG(sbi, *newseg);
+	unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
 	unsigned int left_start = hint;
 	bool init = true;
 	int go_left = 0;
@@ -1199,8 +1735,8 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
 
 	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
 		segno = find_next_zero_bit(free_i->free_segmap,
-				(hint + 1) * sbi->segs_per_sec, *newseg + 1);
-		if (segno < (hint + 1) * sbi->segs_per_sec)
+			GET_SEG_FROM_SEC(sbi, hint + 1), *newseg + 1);
+		if (segno < GET_SEG_FROM_SEC(sbi, hint + 1))
 			goto got_it;
 	}
 find_other_zone:
@@ -1231,8 +1767,8 @@ find_other_zone:
 	secno = left_start;
 skip_left:
 	hint = secno;
-	segno = secno * sbi->segs_per_sec;
-	zoneno = secno / sbi->secs_per_zone;
+	segno = GET_SEG_FROM_SEC(sbi, secno);
+	zoneno = GET_ZONE_FROM_SEC(sbi, secno);
 
 	/* give up on finding another zone */
 	if (!init)
@@ -1276,7 +1812,7 @@ static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
 	struct summary_footer *sum_footer;
 
 	curseg->segno = curseg->next_segno;
-	curseg->zone = GET_ZONENO_FROM_SEGNO(sbi, curseg->segno);
+	curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno);
 	curseg->next_blkoff = 0;
 	curseg->next_segno = NULL_SEGNO;
 
@@ -1289,6 +1825,20 @@ static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
 	__set_sit_entry_type(sbi, type, curseg->segno, modified);
 }
 
+static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
+{
+	/* if segs_per_sec is large than 1, we need to keep original policy. */
+	if (sbi->segs_per_sec != 1)
+		return CURSEG_I(sbi, type)->segno;
+
+	if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
+		return 0;
+
+	if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
+		return SIT_I(sbi)->last_victim[ALLOC_NEXT];
+	return CURSEG_I(sbi, type)->segno;
+}
+
 /*
  * Allocate a current working segment.
  * This function always allocates a free segment in LFS manner.
@@ -1307,6 +1857,7 @@ static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
 	if (test_opt(sbi, NOHEAP))
 		dir = ALLOC_RIGHT;
 
+	segno = __get_next_segno(sbi, type);
 	get_new_segment(sbi, &segno, new_sec, dir);
 	curseg->next_segno = segno;
 	reset_curseg(sbi, type, 1);
@@ -1382,16 +1933,43 @@ static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
 {
 	struct curseg_info *curseg = CURSEG_I(sbi, type);
 	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
+	unsigned segno = NULL_SEGNO;
+	int i, cnt;
+	bool reversed = false;
 
-	if (IS_NODESEG(type) || !has_not_enough_free_secs(sbi, 0, 0))
-		return v_ops->get_victim(sbi,
-				&(curseg)->next_segno, BG_GC, type, SSR);
+	/* need_SSR() already forces to do this */
+	if (v_ops->get_victim(sbi, &segno, BG_GC, type, SSR)) {
+		curseg->next_segno = segno;
+		return 1;
+	}
 
-	/* For data segments, let's do SSR more intensively */
-	for (; type >= CURSEG_HOT_DATA; type--)
-		if (v_ops->get_victim(sbi, &(curseg)->next_segno,
-						BG_GC, type, SSR))
+	/* For node segments, let's do SSR more intensively */
+	if (IS_NODESEG(type)) {
+		if (type >= CURSEG_WARM_NODE) {
+			reversed = true;
+			i = CURSEG_COLD_NODE;
+		} else {
+			i = CURSEG_HOT_NODE;
+		}
+		cnt = NR_CURSEG_NODE_TYPE;
+	} else {
+		if (type >= CURSEG_WARM_DATA) {
+			reversed = true;
+			i = CURSEG_COLD_DATA;
+		} else {
+			i = CURSEG_HOT_DATA;
+		}
+		cnt = NR_CURSEG_DATA_TYPE;
+	}
+
+	for (; cnt-- > 0; reversed ? i-- : i++) {
+		if (i == type)
+			continue;
+		if (v_ops->get_victim(sbi, &segno, BG_GC, i, SSR)) {
+			curseg->next_segno = segno;
 			return 1;
+		}
+	}
 	return 0;
 }
 
@@ -1406,7 +1984,8 @@ static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
 
 	if (force)
 		new_curseg(sbi, type, true);
-	else if (type == CURSEG_WARM_NODE)
+	else if (!is_set_ckpt_flags(sbi, CP_CRC_RECOVERY_FLAG) &&
+					type == CURSEG_WARM_NODE)
 		new_curseg(sbi, type, false);
 	else if (curseg->alloc_type == LFS && is_next_segment_free(sbi, type))
 		new_curseg(sbi, type, false);
@@ -1424,9 +2003,6 @@ void allocate_new_segments(struct f2fs_sb_info *sbi)
 	unsigned int old_segno;
 	int i;
 
-	if (test_opt(sbi, LFS))
-		return;
-
 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
 		curseg = CURSEG_I(sbi, i);
 		old_segno = curseg->segno;
@@ -1439,6 +2015,24 @@ static const struct segment_allocation default_salloc_ops = {
 	.allocate_segment = allocate_segment_by_default,
 };
 
+bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
+	__u64 trim_start = cpc->trim_start;
+	bool has_candidate = false;
+
+	mutex_lock(&SIT_I(sbi)->sentry_lock);
+	for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) {
+		if (add_discard_addrs(sbi, cpc, true)) {
+			has_candidate = true;
+			break;
+		}
+	}
+	mutex_unlock(&SIT_I(sbi)->sentry_lock);
+
+	cpc->trim_start = trim_start;
+	return has_candidate;
+}
+
 int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
 {
 	__u64 start = F2FS_BYTES_TO_BLK(range->start);
@@ -1502,68 +2096,80 @@ static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
 	return false;
 }
 
-static int __get_segment_type_2(struct page *page, enum page_type p_type)
+static int __get_segment_type_2(struct f2fs_io_info *fio)
 {
-	if (p_type == DATA)
+	if (fio->type == DATA)
 		return CURSEG_HOT_DATA;
 	else
 		return CURSEG_HOT_NODE;
 }
 
-static int __get_segment_type_4(struct page *page, enum page_type p_type)
+static int __get_segment_type_4(struct f2fs_io_info *fio)
 {
-	if (p_type == DATA) {
-		struct inode *inode = page->mapping->host;
+	if (fio->type == DATA) {
+		struct inode *inode = fio->page->mapping->host;
 
 		if (S_ISDIR(inode->i_mode))
 			return CURSEG_HOT_DATA;
 		else
 			return CURSEG_COLD_DATA;
 	} else {
-		if (IS_DNODE(page) && is_cold_node(page))
+		if (IS_DNODE(fio->page) && is_cold_node(fio->page))
 			return CURSEG_WARM_NODE;
 		else
 			return CURSEG_COLD_NODE;
 	}
 }
 
-static int __get_segment_type_6(struct page *page, enum page_type p_type)
+static int __get_segment_type_6(struct f2fs_io_info *fio)
 {
-	if (p_type == DATA) {
-		struct inode *inode = page->mapping->host;
+	if (fio->type == DATA) {
+		struct inode *inode = fio->page->mapping->host;
 
-		if (S_ISDIR(inode->i_mode))
-			return CURSEG_HOT_DATA;
-		else if (is_cold_data(page) || file_is_cold(inode))
+		if (is_cold_data(fio->page) || file_is_cold(inode))
 			return CURSEG_COLD_DATA;
-		else
-			return CURSEG_WARM_DATA;
+		if (is_inode_flag_set(inode, FI_HOT_DATA))
+			return CURSEG_HOT_DATA;
+		return CURSEG_WARM_DATA;
 	} else {
-		if (IS_DNODE(page))
-			return is_cold_node(page) ? CURSEG_WARM_NODE :
+		if (IS_DNODE(fio->page))
+			return is_cold_node(fio->page) ? CURSEG_WARM_NODE :
 						CURSEG_HOT_NODE;
-		else
-			return CURSEG_COLD_NODE;
+		return CURSEG_COLD_NODE;
 	}
 }
 
-static int __get_segment_type(struct page *page, enum page_type p_type)
+static int __get_segment_type(struct f2fs_io_info *fio)
 {
-	switch (F2FS_P_SB(page)->active_logs) {
+	int type = 0;
+
+	switch (fio->sbi->active_logs) {
 	case 2:
-		return __get_segment_type_2(page, p_type);
+		type = __get_segment_type_2(fio);
+		break;
 	case 4:
-		return __get_segment_type_4(page, p_type);
+		type = __get_segment_type_4(fio);
+		break;
+	case 6:
+		type = __get_segment_type_6(fio);
+		break;
+	default:
+		f2fs_bug_on(fio->sbi, true);
 	}
-	/* NR_CURSEG_TYPE(6) logs by default */
-	f2fs_bug_on(F2FS_P_SB(page),
-		F2FS_P_SB(page)->active_logs != NR_CURSEG_TYPE);
-	return __get_segment_type_6(page, p_type);
+
+	if (IS_HOT(type))
+		fio->temp = HOT;
+	else if (IS_WARM(type))
+		fio->temp = WARM;
+	else
+		fio->temp = COLD;
+	return type;
 }
 
 void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 		block_t old_blkaddr, block_t *new_blkaddr,
-		struct f2fs_summary *sum, int type)
+		struct f2fs_summary *sum, int type,
+		struct f2fs_io_info *fio, bool add_list)
 {
 	struct sit_info *sit_i = SIT_I(sbi);
 	struct curseg_info *curseg = CURSEG_I(sbi, type);
@@ -1573,6 +2179,8 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 
 	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
 
+	f2fs_wait_discard_bio(sbi, *new_blkaddr);
+
 	/*
 	 * __add_sum_entry should be resided under the curseg_mutex
 	 * because, this function updates a summary entry in the
@@ -1587,8 +2195,8 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	if (!__has_curseg_space(sbi, type))
 		sit_i->s_ops->allocate_segment(sbi, type, false);
 	/*
-	 * SIT information should be updated before segment allocation,
-	 * since SSR needs latest valid block information.
+	 * SIT information should be updated after segment allocation,
+	 * since we need to keep dirty segments precisely under SSR.
 	 */
 	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
 
@@ -1597,24 +2205,35 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	if (page && IS_NODESEG(type))
 		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
 
+	if (add_list) {
+		struct f2fs_bio_info *io;
+
+		INIT_LIST_HEAD(&fio->list);
+		fio->in_list = true;
+		io = sbi->write_io[fio->type] + fio->temp;
+		spin_lock(&io->io_lock);
+		list_add_tail(&fio->list, &io->io_list);
+		spin_unlock(&io->io_lock);
+	}
+
 	mutex_unlock(&curseg->curseg_mutex);
 }
 
 static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
 {
-	int type = __get_segment_type(fio->page, fio->type);
-
-	if (fio->type == NODE || fio->type == DATA)
-		mutex_lock(&fio->sbi->wio_mutex[fio->type]);
+	int type = __get_segment_type(fio);
+	int err;
 
+reallocate:
 	allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
-					&fio->new_blkaddr, sum, type);
+			&fio->new_blkaddr, sum, type, fio, true);
 
 	/* writeout dirty page into bdev */
-	f2fs_submit_page_mbio(fio);
-
-	if (fio->type == NODE || fio->type == DATA)
-		mutex_unlock(&fio->sbi->wio_mutex[fio->type]);
+	err = f2fs_submit_page_write(fio);
+	if (err == -EAGAIN) {
+		fio->old_blkaddr = fio->new_blkaddr;
+		goto reallocate;
+	}
 }
 
 void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
@@ -1628,13 +2247,14 @@ void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
 		.new_blkaddr = page->index,
 		.page = page,
 		.encrypted_page = NULL,
+		.in_list = false,
 	};
 
 	if (unlikely(page->index >= MAIN_BLKADDR(sbi)))
 		fio.op_flags &= ~REQ_META;
 
 	set_page_writeback(page);
-	f2fs_submit_page_mbio(&fio);
+	f2fs_submit_page_write(&fio);
 }
 
 void write_node_page(unsigned int nid, struct f2fs_io_info *fio)
@@ -1658,11 +2278,11 @@ void write_data_page(struct dnode_of_data *dn, struct f2fs_io_info *fio)
 	f2fs_update_data_blkaddr(dn, fio->new_blkaddr);
 }
 
-void rewrite_data_page(struct f2fs_io_info *fio)
+int rewrite_data_page(struct f2fs_io_info *fio)
 {
 	fio->new_blkaddr = fio->old_blkaddr;
 	stat_inc_inplace_blocks(fio->sbi);
-	f2fs_submit_page_mbio(fio);
+	return f2fs_submit_page_bio(fio);
 }
 
 void __f2fs_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
@@ -1753,7 +2373,8 @@ void f2fs_wait_on_page_writeback(struct page *page,
 	if (PageWriteback(page)) {
 		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
 
-		f2fs_submit_merged_bio_cond(sbi, NULL, page, 0, type, WRITE);
+		f2fs_submit_merged_write_cond(sbi, page->mapping->host,
+						0, page->index, type);
 		if (ordered)
 			wait_on_page_writeback(page);
 		else
@@ -1911,6 +2532,8 @@ static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
 
 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
 {
+	struct f2fs_journal *sit_j = CURSEG_I(sbi, CURSEG_COLD_DATA)->journal;
+	struct f2fs_journal *nat_j = CURSEG_I(sbi, CURSEG_HOT_DATA)->journal;
 	int type = CURSEG_HOT_DATA;
 	int err;
 
@@ -1937,6 +2560,11 @@ static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
 			return err;
 	}
 
+	/* sanity check for summary blocks */
+	if (nats_in_cursum(nat_j) > NAT_JOURNAL_ENTRIES ||
+			sits_in_cursum(sit_j) > SIT_JOURNAL_ENTRIES)
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -2226,9 +2854,9 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 			se = get_seg_entry(sbi, segno);
 
 			/* add discard candidates */
-			if (cpc->reason != CP_DISCARD) {
+			if (!(cpc->reason & CP_DISCARD)) {
 				cpc->trim_start = segno;
-				add_discard_addrs(sbi, cpc);
+				add_discard_addrs(sbi, cpc, false);
 			}
 
 			if (to_journal) {
@@ -2262,9 +2890,13 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	f2fs_bug_on(sbi, !list_empty(head));
 	f2fs_bug_on(sbi, sit_i->dirty_sentries);
 out:
-	if (cpc->reason == CP_DISCARD) {
+	if (cpc->reason & CP_DISCARD) {
+		__u64 trim_start = cpc->trim_start;
+
 		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
-			add_discard_addrs(sbi, cpc);
+			add_discard_addrs(sbi, cpc, false);
+
+		cpc->trim_start = trim_start;
 	}
 	mutex_unlock(&sit_i->sentry_lock);
 
@@ -2276,7 +2908,7 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
 	struct sit_info *sit_i;
 	unsigned int sit_segs, start;
-	char *src_bitmap, *dst_bitmap;
+	char *src_bitmap;
 	unsigned int bitmap_size;
 
 	/* allocate memory for SIT information */
@@ -2286,13 +2918,13 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 
 	SM_I(sbi)->sit_info = sit_i;
 
-	sit_i->sentries = f2fs_kvzalloc(MAIN_SEGS(sbi) *
+	sit_i->sentries = kvzalloc(MAIN_SEGS(sbi) *
 					sizeof(struct seg_entry), GFP_KERNEL);
 	if (!sit_i->sentries)
 		return -ENOMEM;
 
 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
-	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
+	sit_i->dirty_sentries_bitmap = kvzalloc(bitmap_size, GFP_KERNEL);
 	if (!sit_i->dirty_sentries_bitmap)
 		return -ENOMEM;
 
@@ -2305,6 +2937,13 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 				!sit_i->sentries[start].ckpt_valid_map)
 			return -ENOMEM;
 
+#ifdef CONFIG_F2FS_CHECK_FS
+		sit_i->sentries[start].cur_valid_map_mir
+			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
+		if (!sit_i->sentries[start].cur_valid_map_mir)
+			return -ENOMEM;
+#endif
+
 		if (f2fs_discard_en(sbi)) {
 			sit_i->sentries[start].discard_map
 				= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
@@ -2318,7 +2957,7 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 		return -ENOMEM;
 
 	if (sbi->segs_per_sec > 1) {
-		sit_i->sec_entries = f2fs_kvzalloc(MAIN_SECS(sbi) *
+		sit_i->sec_entries = kvzalloc(MAIN_SECS(sbi) *
 					sizeof(struct sec_entry), GFP_KERNEL);
 		if (!sit_i->sec_entries)
 			return -ENOMEM;
@@ -2331,22 +2970,27 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
 	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
 
-	dst_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
-	if (!dst_bitmap)
+	sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+	if (!sit_i->sit_bitmap)
 		return -ENOMEM;
 
+#ifdef CONFIG_F2FS_CHECK_FS
+	sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+	if (!sit_i->sit_bitmap_mir)
+		return -ENOMEM;
+#endif
+
 	/* init SIT information */
 	sit_i->s_ops = &default_salloc_ops;
 
 	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
 	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
 	sit_i->written_valid_blocks = 0;
-	sit_i->sit_bitmap = dst_bitmap;
 	sit_i->bitmap_size = bitmap_size;
 	sit_i->dirty_sentries = 0;
 	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
 	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
-	sit_i->mounted_time = CURRENT_TIME_SEC.tv_sec;
+	sit_i->mounted_time = ktime_get_real_seconds();
 	mutex_init(&sit_i->sentry_lock);
 	return 0;
 }
@@ -2364,12 +3008,12 @@ static int build_free_segmap(struct f2fs_sb_info *sbi)
 	SM_I(sbi)->free_info = free_i;
 
 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
-	free_i->free_segmap = f2fs_kvmalloc(bitmap_size, GFP_KERNEL);
+	free_i->free_segmap = kvmalloc(bitmap_size, GFP_KERNEL);
 	if (!free_i->free_segmap)
 		return -ENOMEM;
 
 	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
-	free_i->free_secmap = f2fs_kvmalloc(sec_bitmap_size, GFP_KERNEL);
+	free_i->free_secmap = kvmalloc(sec_bitmap_size, GFP_KERNEL);
 	if (!free_i->free_secmap)
 		return -ENOMEM;
 
@@ -2445,10 +3089,17 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
 
 			/* build discard map only one time */
 			if (f2fs_discard_en(sbi)) {
-				memcpy(se->discard_map, se->cur_valid_map,
-							SIT_VBLOCK_MAP_SIZE);
-				sbi->discard_blks += sbi->blocks_per_seg -
-							se->valid_blocks;
+				if (is_set_ckpt_flags(sbi, CP_TRIMMED_FLAG)) {
+					memset(se->discard_map, 0xff,
+						SIT_VBLOCK_MAP_SIZE);
+				} else {
+					memcpy(se->discard_map,
+						se->cur_valid_map,
+						SIT_VBLOCK_MAP_SIZE);
+					sbi->discard_blks +=
+						sbi->blocks_per_seg -
+						se->valid_blocks;
+				}
 			}
 
 			if (sbi->segs_per_sec > 1)
@@ -2472,10 +3123,15 @@ static void build_sit_entries(struct f2fs_sb_info *sbi)
 		seg_info_from_raw_sit(se, &sit);
 
 		if (f2fs_discard_en(sbi)) {
-			memcpy(se->discard_map, se->cur_valid_map,
-						SIT_VBLOCK_MAP_SIZE);
-			sbi->discard_blks += old_valid_blocks -
-						se->valid_blocks;
+			if (is_set_ckpt_flags(sbi, CP_TRIMMED_FLAG)) {
+				memset(se->discard_map, 0xff,
+							SIT_VBLOCK_MAP_SIZE);
+			} else {
+				memcpy(se->discard_map, se->cur_valid_map,
+							SIT_VBLOCK_MAP_SIZE);
+				sbi->discard_blks += old_valid_blocks -
+							se->valid_blocks;
+			}
 		}
 
 		if (sbi->segs_per_sec > 1)
@@ -2519,7 +3175,7 @@ static void init_dirty_segmap(struct f2fs_sb_info *sbi)
 		if (segno >= MAIN_SEGS(sbi))
 			break;
 		offset = segno + 1;
-		valid_blocks = get_valid_blocks(sbi, segno, 0);
+		valid_blocks = get_valid_blocks(sbi, segno, false);
 		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
 			continue;
 		if (valid_blocks > sbi->blocks_per_seg) {
@@ -2537,7 +3193,7 @@ 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(MAIN_SECS(sbi));
 
-	dirty_i->victim_secmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
+	dirty_i->victim_secmap = kvzalloc(bitmap_size, GFP_KERNEL);
 	if (!dirty_i->victim_secmap)
 		return -ENOMEM;
 	return 0;
@@ -2559,7 +3215,7 @@ static int build_dirty_segmap(struct f2fs_sb_info *sbi)
 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
 
 	for (i = 0; i < NR_DIRTY_TYPE; i++) {
-		dirty_i->dirty_segmap[i] = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
+		dirty_i->dirty_segmap[i] = kvzalloc(bitmap_size, GFP_KERNEL);
 		if (!dirty_i->dirty_segmap[i])
 			return -ENOMEM;
 	}
@@ -2625,22 +3281,22 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
 		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);
-	INIT_LIST_HEAD(&sm_info->wait_list);
-	sm_info->nr_discards = 0;
-	sm_info->max_discards = 0;
+	sm_info->min_hot_blocks = DEF_MIN_HOT_BLOCKS;
 
 	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)) {
+	if (!f2fs_readonly(sbi->sb)) {
 		err = create_flush_cmd_control(sbi);
 		if (err)
 			return err;
 	}
 
+	err = create_discard_cmd_control(sbi);
+	if (err)
+		return err;
+
 	err = build_sit_info(sbi);
 	if (err)
 		return err;
@@ -2734,6 +3390,9 @@ static void destroy_sit_info(struct f2fs_sb_info *sbi)
 	if (sit_i->sentries) {
 		for (start = 0; start < MAIN_SEGS(sbi); start++) {
 			kfree(sit_i->sentries[start].cur_valid_map);
+#ifdef CONFIG_F2FS_CHECK_FS
+			kfree(sit_i->sentries[start].cur_valid_map_mir);
+#endif
 			kfree(sit_i->sentries[start].ckpt_valid_map);
 			kfree(sit_i->sentries[start].discard_map);
 		}
@@ -2746,6 +3405,9 @@ static void destroy_sit_info(struct f2fs_sb_info *sbi)
 
 	SM_I(sbi)->sit_info = NULL;
 	kfree(sit_i->sit_bitmap);
+#ifdef CONFIG_F2FS_CHECK_FS
+	kfree(sit_i->sit_bitmap_mir);
+#endif
 	kfree(sit_i);
 }
 
@@ -2756,6 +3418,7 @@ void destroy_segment_manager(struct f2fs_sb_info *sbi)
 	if (!sm_info)
 		return;
 	destroy_flush_cmd_control(sbi, true);
+	destroy_discard_cmd_control(sbi);
 	destroy_dirty_segmap(sbi);
 	destroy_curseg(sbi);
 	destroy_free_segmap(sbi);
@@ -2771,15 +3434,15 @@ int __init create_segment_manager_caches(void)
 	if (!discard_entry_slab)
 		goto fail;
 
-	bio_entry_slab = f2fs_kmem_cache_create("bio_entry",
-			sizeof(struct bio_entry));
-	if (!bio_entry_slab)
+	discard_cmd_slab = f2fs_kmem_cache_create("discard_cmd",
+			sizeof(struct discard_cmd));
+	if (!discard_cmd_slab)
 		goto destroy_discard_entry;
 
 	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
 			sizeof(struct sit_entry_set));
 	if (!sit_entry_set_slab)
-		goto destroy_bio_entry;
+		goto destroy_discard_cmd;
 
 	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
 			sizeof(struct inmem_pages));
@@ -2789,8 +3452,8 @@ int __init create_segment_manager_caches(void)
 
 destroy_sit_entry_set:
 	kmem_cache_destroy(sit_entry_set_slab);
-destroy_bio_entry:
-	kmem_cache_destroy(bio_entry_slab);
+destroy_discard_cmd:
+	kmem_cache_destroy(discard_cmd_slab);
 destroy_discard_entry:
 	kmem_cache_destroy(discard_entry_slab);
 fail:
@@ -2800,7 +3463,7 @@ fail:
 void destroy_segment_manager_caches(void)
 {
 	kmem_cache_destroy(sit_entry_set_slab);
-	kmem_cache_destroy(bio_entry_slab);
+	kmem_cache_destroy(discard_cmd_slab);
 	kmem_cache_destroy(discard_entry_slab);
 	kmem_cache_destroy(inmem_entry_slab);
 }