[f2fs-dev,3/3,v2] f2fs: use lock_buffer when changing superblock

Commit Message

Jaegeuk Kim Dec. 9, 2015, 5:54 p.m. UTC

Agreed.

Change log from v1:
 o apply for _undo_ flow as well

From ea212a4a7a432e0ecd0f0f53971b70172b3e7f96 Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <[e-mail]>
Date: Mon, 7 Dec 2015 10:18:54 -0800
Subject: [PATCH] f2fs: use lock_buffer when changing superblock

When modifying sb contents, we need to use lock its buffer.

Signed-off-by: Jaegeuk Kim <[e-mail]>
---
 fs/f2fs/file.c | 4 ++++
 1 file changed, 4 insertions(+)

Patch

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index a018ed3..294e715 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1591,14 +1591,18 @@  static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
 		return err;
 
 	/* update superblock with uuid */
+	lock_buffer(sbi->raw_super_buf);
 	generate_random_uuid(sbi->raw_super->encrypt_pw_salt);
+	unlock_buffer(sbi->raw_super_buf);
 
 	err = f2fs_commit_super(sbi, false);
 
 	mnt_drop_write_file(filp);
 	if (err) {
 		/* undo new data */
+		lock_buffer(sbi->raw_super_buf);
 		memset(sbi->raw_super->encrypt_pw_salt, 0, 16);
+		unlock_buffer(sbi->raw_super_buf);
 		return err;
 	}
 got_it: