f2fs: Fix recovery is too slow when power fail on much fsync

By default fsync option, if fsync is called frequently, and suddenly
lost power, the POR will consume too much memory at mounting, this
process may be very slow due to a large number of swapping.

Change-Id: I8235098cca062d7ab58af4ebed414aed9aba6c75
Signed-off-by: Cliff Chen <cliff.chen@rock-chips.com>

3 files changed, 27 insertions, 1 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2c10b09d9bcf..fb96427997f4 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1335,6 +1335,8 @@ struct f2fs_sb_info {
 	/* migration granularity of garbage collection, unit: segment */
 	unsigned int migration_granularity;
 
+	atomic_t no_cp_fsync_pages;
+
 	/*
 	 * for stat information.
 	 * one is for the LFS mode, and the other is for the SSR mode.
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 637a9dfbd578..78f0c3b78427 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -198,6 +198,25 @@ static void try_to_fix_pino(struct inode *inode)
 	up_write(&fi->i_sem);
 }
 
+static bool f2fs_update_fsync_count(struct f2fs_sb_info *sbi,
+					unsigned int npages)
+{
+	struct sysinfo val;
+	unsigned long avail_ram;
+
+	si_meminfo(&val);
+
+	/* only uses low memory */
+	avail_ram = val.totalram - val.totalhigh;
+	avail_ram = (avail_ram * DEF_RAM_THRESHOLD) / 100;
+
+	if ((atomic_read(&sbi->no_cp_fsync_pages) + npages) > avail_ram)
+		return false;
+
+	atomic_add(npages, &sbi->no_cp_fsync_pages);
+	return true;
+}
+
 static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
 						int datasync, bool atomic)
 {
@@ -205,6 +224,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	nid_t ino = inode->i_ino;
 	int ret = 0;
+	unsigned int npages = 0;
 	enum cp_reason_type cp_reason = 0;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_ALL,
@@ -223,6 +243,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
 		goto go_write;
 
 	/* if fdatasync is triggered, let's do in-place-update */
+	npages = get_dirty_pages(inode);
 	if (datasync || get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks)
 		set_inode_flag(inode, FI_NEED_IPU);
 	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
@@ -263,7 +284,7 @@ go_write:
 	cp_reason = need_do_checkpoint(inode);
 	up_read(&F2FS_I(inode)->i_sem);
 
-	if (cp_reason) {
+	if (cp_reason || !f2fs_update_fsync_count(sbi, npages)) {
 		/* all the dirty node pages should be flushed for POR */
 		ret = f2fs_sync_fs(inode->i_sb, 1);
 
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 463b21e3cd78..84eaa5e76d69 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1140,6 +1140,7 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
 
 		cpc.reason = __get_cp_reason(sbi);
 
+		atomic_set(&sbi->no_cp_fsync_pages, 0);
 		mutex_lock(&sbi->gc_mutex);
 		err = f2fs_write_checkpoint(sbi, &cpc);
 		mutex_unlock(&sbi->gc_mutex);
@@ -3305,6 +3306,8 @@ try_onemore:
 
 	f2fs_build_gc_manager(sbi);
 
+	atomic_set(&sbi->no_cp_fsync_pages, 0);
+
 	err = f2fs_build_stats(sbi);
 	if (err)
 		goto free_nm;