f2fs: reduce expensive checkpoint trigger frequency

We may trigger high frequent checkpoint for below case:
1. mkdir /mnt/dir1; set dir1 encrypted
2. touch /mnt/file1; fsync /mnt/file1
3. mkdir /mnt/dir2; set dir2 encrypted
4. touch /mnt/file2; fsync /mnt/file2
...

Although, newly created dir and file are not related, due to
commit bbf156f7 ("f2fs: fix lost xattrs of directories"), we will
trigger checkpoint whenever fsync() comes after a new encrypted dir
created.

In order to avoid such performance regression issue, let's record an
entry including directory's ino in global cache whenever we update
directory's xattr data, and then triggerring checkpoint() only if
xattr metadata of target file's parent was updated.

This patch updates to cover below no encryption case as well:
1) parent is checkpointed
2) set_xattr(dir) w/ new xnid
3) create(file)
4) fsync(file)

Fixes: bbf156f7 ("f2fs: fix lost xattrs of directories")
Reported-by: wangzijie <wangzijie1@honor.com>
Reported-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Tested-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reported-by: Yunlei He <heyunlei@hihonor.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -291,6 +291,7 @@ enum {
 	APPEND_INO,		/* for append ino list */
 	UPDATE_INO,		/* for update ino list */
 	TRANS_DIR_INO,		/* for transactions dir ino list */
+	XATTR_DIR_INO,		/* for xattr updated dir ino list */
 	FLUSH_INO,		/* for multiple device flushing */
 	MAX_INO_ENTRY,		/* max. list */
 };
@@ -1161,6 +1162,7 @@ enum cp_reason_type {
 	CP_FASTBOOT_MODE,
 	CP_SPEC_LOG_NUM,
 	CP_RECOVER_DIR,
+	CP_XATTR_DIR,
 };
 
 enum iostat_type {

fs/f2fs/file.c

@@ -218,6 +218,9 @@ static inline enum cp_reason_type need_do_checkpoint(struct inode *inode)
 		f2fs_exist_written_data(sbi, F2FS_I(inode)->i_pino,
 							TRANS_DIR_INO))
 		cp_reason = CP_RECOVER_DIR;
+	else if (f2fs_exist_written_data(sbi, F2FS_I(inode)->i_pino,
+							XATTR_DIR_INO))
+		cp_reason = CP_XATTR_DIR;
 
 	return cp_reason;
 }

fs/f2fs/xattr.c

@@ -629,6 +629,7 @@ static int __f2fs_setxattr(struct inode *inode, int index,
 			const char *name, const void *value, size_t size,
 			struct page *ipage, int flags)
 {
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct f2fs_xattr_entry *here, *last;
 	void *base_addr, *last_base_addr;
 	int found, newsize;
@@ -772,9 +773,18 @@ static int __f2fs_setxattr(struct inode *inode, int index,
 	if (index == F2FS_XATTR_INDEX_ENCRYPTION &&
 			!strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT))
 		f2fs_set_encrypted_inode(inode);
-	if (S_ISDIR(inode->i_mode))
-		set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP);
 
+	if (!S_ISDIR(inode->i_mode))
+		goto same;
+	/*
+	 * In restrict mode, fsync() always try to trigger checkpoint for all
+	 * metadata consistency, in other mode, it triggers checkpoint when
+	 * parent's xattr metadata was updated.
+	 */
+	if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
+		set_sbi_flag(sbi, SBI_NEED_CP);
+	else
+		f2fs_add_ino_entry(sbi, inode->i_ino, XATTR_DIR_INO);
 same:
 	if (is_inode_flag_set(inode, FI_ACL_MODE)) {
 		inode->i_mode = F2FS_I(inode)->i_acl_mode;

include/trace/events/f2fs.h

@@ -139,7 +139,8 @@ TRACE_DEFINE_ENUM(EX_BLOCK_AGE);
 		{ CP_NODE_NEED_CP,	"node needs cp" },		\
 		{ CP_FASTBOOT_MODE,	"fastboot mode" },		\
 		{ CP_SPEC_LOG_NUM,	"log type is 2" },		\
-		{ CP_RECOVER_DIR,	"dir needs recovery" })
+		{ CP_RECOVER_DIR,	"dir needs recovery" },		\
+		{ CP_XATTR_DIR,		"dir's xattr updated" })
 
 #define show_shutdown_mode(type)					\
 	__print_symbolic(type,						\