From 39d787bec4f792e69e24b11aa3d61ae1c0e4830b Mon Sep 17 00:00:00 2001
From: Chao Yu <yuchao0@huawei.com>
Date: Fri, 29 Sep 2017 13:59:38 +0800
Subject: f2fs: enhance multiple device flush

When multiple device feature is enabled, during ->fsync we will issue
flush in all devices to make sure node/data of the file being persisted
into storage. But some flushes of device could be unneeded as file's
data may be not writebacked into those devices. So this patch adds and
manage bitmap per inode in global cache to indicate which device is
dirty and it needs to issue flush during ->fsync, hence, we could improve
performance of fsync in scenario of multiple device.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/segment.c | 46 +++++++++++++++++++++++++++++++++++-----------
 1 file changed, 35 insertions(+), 11 deletions(-)

(limited to 'fs/f2fs/segment.c')

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c695ff462ee6..8fcb1d3a6ea4 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -313,6 +313,7 @@ static int __commit_inmem_pages(struct inode *inode,
 	struct inmem_pages *cur, *tmp;
 	struct f2fs_io_info fio = {
 		.sbi = sbi,
+		.ino = inode->i_ino,
 		.type = DATA,
 		.op = REQ_OP_WRITE,
 		.op_flags = REQ_SYNC | REQ_PRIO,
@@ -485,15 +486,17 @@ static int __submit_flush_wait(struct f2fs_sb_info *sbi,
 	return ret;
 }
 
-static int submit_flush_wait(struct f2fs_sb_info *sbi)
+static int submit_flush_wait(struct f2fs_sb_info *sbi, nid_t ino)
 {
-	int ret = __submit_flush_wait(sbi, sbi->sb->s_bdev);
+	int ret = 0;
 	int i;
 
-	if (!sbi->s_ndevs || ret)
-		return ret;
+	if (!sbi->s_ndevs)
+		return __submit_flush_wait(sbi, sbi->sb->s_bdev);
 
-	for (i = 1; i < sbi->s_ndevs; i++) {
+	for (i = 0; i < sbi->s_ndevs; i++) {
+		if (!is_dirty_device(sbi, ino, i, FLUSH_INO))
+			continue;
 		ret = __submit_flush_wait(sbi, FDEV(i).bdev);
 		if (ret)
 			break;
@@ -519,7 +522,9 @@ repeat:
 		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
 		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
 
-		ret = submit_flush_wait(sbi);
+		cmd = llist_entry(fcc->dispatch_list, struct flush_cmd, llnode);
+
+		ret = submit_flush_wait(sbi, cmd->ino);
 		atomic_inc(&fcc->issued_flush);
 
 		llist_for_each_entry_safe(cmd, next,
@@ -537,7 +542,7 @@ repeat:
 	goto repeat;
 }
 
-int f2fs_issue_flush(struct f2fs_sb_info *sbi)
+int f2fs_issue_flush(struct f2fs_sb_info *sbi, nid_t ino)
 {
 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
 	struct flush_cmd cmd;
@@ -547,19 +552,20 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
 		return 0;
 
 	if (!test_opt(sbi, FLUSH_MERGE)) {
-		ret = submit_flush_wait(sbi);
+		ret = submit_flush_wait(sbi, ino);
 		atomic_inc(&fcc->issued_flush);
 		return ret;
 	}
 
-	if (atomic_inc_return(&fcc->issing_flush) == 1) {
-		ret = submit_flush_wait(sbi);
+	if (atomic_inc_return(&fcc->issing_flush) == 1 || sbi->s_ndevs > 1) {
+		ret = submit_flush_wait(sbi, ino);
 		atomic_dec(&fcc->issing_flush);
 
 		atomic_inc(&fcc->issued_flush);
 		return ret;
 	}
 
+	cmd.ino = ino;
 	init_completion(&cmd.wait);
 
 	llist_add(&cmd.llnode, &fcc->issue_list);
@@ -583,7 +589,7 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
 		} else {
 			struct flush_cmd *tmp, *next;
 
-			ret = submit_flush_wait(sbi);
+			ret = submit_flush_wait(sbi, ino);
 
 			llist_for_each_entry_safe(tmp, next, list, llnode) {
 				if (tmp == &cmd) {
@@ -2384,6 +2390,20 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	mutex_unlock(&curseg->curseg_mutex);
 }
 
+static void update_device_state(struct f2fs_io_info *fio)
+{
+	struct f2fs_sb_info *sbi = fio->sbi;
+	unsigned int devidx;
+
+	if (!sbi->s_ndevs)
+		return;
+
+	devidx = f2fs_target_device_index(sbi, fio->new_blkaddr);
+
+	/* update device state for fsync */
+	set_dirty_device(sbi, fio->ino, devidx, FLUSH_INO);
+}
+
 static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
 {
 	int type = __get_segment_type(fio);
@@ -2398,6 +2418,8 @@ reallocate:
 	if (err == -EAGAIN) {
 		fio->old_blkaddr = fio->new_blkaddr;
 		goto reallocate;
+	} else if (!err) {
+		update_device_state(fio);
 	}
 }
 
@@ -2458,6 +2480,8 @@ int rewrite_data_page(struct f2fs_io_info *fio)
 	stat_inc_inplace_blocks(fio->sbi);
 
 	err = f2fs_submit_page_bio(fio);
+	if (!err)
+		update_device_state(fio);
 
 	f2fs_update_iostat(fio->sbi, fio->io_type, F2FS_BLKSIZE);
 
-- 
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