linux-kernel - [PATCH v4] f2fs: reduce expensive checkpoint trigger frequency

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Message-Id: <20240625065459.3665791-1-chao@kernel.org>
Date: Tue, 25 Jun 2024 14:54:59 +0800
From: Chao Yu <chao@...nel.org>
To: jaegeuk@...nel.org
Cc: linux-f2fs-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org,
	Chao Yu <chao@...nel.org>,
	wangzijie <wangzijie1@...or.com>,
	Zhiguo Niu <zhiguo.niu@...soc.com>,
	Yunlei He <heyunlei@...onor.com>
Subject: [PATCH v4] 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 bbf156f7afa7 ("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: bbf156f7afa7 ("f2fs: fix lost xattrs of directories")
Reported-by: wangzijie <wangzijie1@...or.com>
Reported-by: Zhiguo Niu <zhiguo.niu@...soc.com>
Tested-by: Zhiguo Niu <zhiguo.niu@...soc.com>
Reported-by: Yunlei He <heyunlei@...onor.com>
Signed-off-by: Chao Yu <chao@...nel.org>
---
 fs/f2fs/f2fs.h              |  2 ++
 fs/f2fs/file.c              |  3 +++
 fs/f2fs/xattr.c             | 14 ++++++++++++--
 include/trace/events/f2fs.h |  3 ++-
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f1d65ee3addf..f3c910b8983b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -284,6 +284,7 @@ enum {
 	APPEND_INO,		/* for append ino list */
 	UPDATE_INO,		/* for update ino list */
 	TRANS_DIR_INO,		/* for transactions dir ino list */
+	ENC_DIR_INO,		/* for encrypted dir ino list */
 	FLUSH_INO,		/* for multiple device flushing */
 	MAX_INO_ENTRY,		/* max. list */
 };
@@ -1150,6 +1151,7 @@ enum cp_reason_type {
 	CP_FASTBOOT_MODE,
 	CP_SPEC_LOG_NUM,
 	CP_RECOVER_DIR,
+	CP_ENC_DIR,
 };
 
 enum iostat_type {
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index a527de1e7a2f..278573974db4 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -217,6 +217,9 @@ 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,
+							ENC_DIR_INO))
+		cp_reason = CP_ENC_DIR;
 
 	return cp_reason;
 }
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index f290fe9327c4..d04c0b47a4e4 100644
--- a/fs/f2fs/xattr.c
+++ b/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, ENC_DIR_INO);
 same:
 	if (is_inode_flag_set(inode, FI_ACL_MODE)) {
 		inode->i_mode = F2FS_I(inode)->i_acl_mode;
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index ed794b5fefbe..e4a94995e9a8 100644
--- a/include/trace/events/f2fs.h
+++ b/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_ENC_DIR,		"persist encryption policy" })
 
 #define show_shutdown_mode(type)					\
 	__print_symbolic(type,						\
-- 
2.40.1