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Commit 93cf93f1 authored by Junling Zheng's avatar Junling Zheng Committed by Jaegeuk Kim
Browse files

f2fs: introduce mount option for fsync mode 



Commit "0a007b97"(f2fs: recover directory operations by fsync)
fixed xfstest generic/342 case, but it also increased the written
data and caused the performance degradation. In most cases, there's
no need to do so heavy fsync actually.

So we introduce new mount option "fsync_mode={posix,strict}" to
control the policy of fsync. "fsync_mode=posix" is set by default,
and means that f2fs uses a light fsync, which follows POSIX semantics.
And "fsync_mode=strict" means that it's a heavy fsync, which behaves
in line with xfs, ext4 and btrfs, where generic/342 will pass, but
the performance will regress.

Signed-off-by: default avatarJunling Zheng <zhengjunling@huawei.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent eea52882

Documentation/filesystems/f2fs.txt

+7 −0
Original line number Diff line number Diff line
@@ -182,6 +182,13 @@ whint_mode=%s Control which write hints are passed down to block 
                       passes down hints with its policy.

alloc_mode=%s          Adjust block allocation policy, which supports "reuse"

                       and "default".

fsync_mode=%s          Control the policy of fsync. Currently supports "posix"

                       and "strict". In "posix" mode, which is default, fsync

                       will follow POSIX semantics and does a light operation

                       to improve the filesystem performance. In "strict" mode,

                       fsync will be heavy and behaves in line with xfs, ext4

                       and btrfs, where xfstest generic/342 will pass, but the

                       performance will regress.



================================================================================

DEBUGFS ENTRIES

fs/f2fs/dir.c

+2 −1
Original line number Diff line number Diff line
@@ -704,6 +704,7 @@ void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page, 


	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);



	if (F2FS_I_SB(dir)->fsync_mode == FSYNC_MODE_STRICT)

		add_ino_entry(F2FS_I_SB(dir), dir->i_ino, TRANS_DIR_INO);



	if (f2fs_has_inline_dentry(dir))

fs/f2fs/f2fs.h

+8 −0
Original line number Diff line number Diff line
@@ -1052,6 +1052,11 @@ enum { 
	ALLOC_MODE_REUSE,	/* reuse segments as much as possible */

};



enum fsync_mode {

	FSYNC_MODE_POSIX,	/* fsync follows posix semantics */

	FSYNC_MODE_STRICT,	/* fsync behaves in line with ext4 */

};



struct f2fs_sb_info {

	struct super_block *sb;			/* pointer to VFS super block */

	struct proc_dir_entry *s_proc;		/* proc entry */
@@ -1241,6 +1246,9 @@ struct f2fs_sb_info { 


	/* segment allocation policy */

	int alloc_mode;



	/* fsync policy */

	int fsync_mode;

};



#ifdef CONFIG_F2FS_FAULT_INJECTION

fs/f2fs/file.c

+2 −1
Original line number Diff line number Diff line
@@ -165,7 +165,8 @@ static inline enum cp_reason_type need_do_checkpoint(struct inode *inode) 
		cp_reason = CP_FASTBOOT_MODE;

	else if (sbi->active_logs == 2)

		cp_reason = CP_SPEC_LOG_NUM;

	else if (need_dentry_mark(sbi, inode->i_ino) &&

	else if (sbi->fsync_mode == FSYNC_MODE_STRICT &&

		need_dentry_mark(sbi, inode->i_ino) &&

		exist_written_data(sbi, F2FS_I(inode)->i_pino, TRANS_DIR_INO))

		cp_reason = CP_RECOVER_DIR;

fs/f2fs/namei.c

+6 −3
Original line number Diff line number Diff line
@@ -970,6 +970,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry, 
			f2fs_put_page(old_dir_page, 0);

		f2fs_i_links_write(old_dir, false);

	}

	if (sbi->fsync_mode == FSYNC_MODE_STRICT)

		add_ino_entry(sbi, new_dir->i_ino, TRANS_DIR_INO);



	f2fs_unlock_op(sbi);
@@ -1120,8 +1121,10 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 
	}

	f2fs_mark_inode_dirty_sync(new_dir, false);



	if (sbi->fsync_mode == FSYNC_MODE_STRICT) {

		add_ino_entry(sbi, old_dir->i_ino, TRANS_DIR_INO);

		add_ino_entry(sbi, new_dir->i_ino, TRANS_DIR_INO);

	}



	f2fs_unlock_op(sbi);