From: Chao Yu <yuch...@huawei.com>
f2fs_super_block.encrypt_pw_salt can be udpated and persisted
concurrently, result in getting different pwsalt in separated
threads, so let's introduce sb_lock to exclude concurrent
accessers.
Signed-off-by: Chao Yu <yuch...@huawei.com>
---
fs/f2fs/f2fs.h | 1 +
fs/f2fs/file.c | 19 +++++++++++--------
fs/f2fs/super.c | 2 ++
3 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 7ed17cd657b5..0332c44a1d93 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1048,6 +1048,7 @@ struct f2fs_sb_info {
struct super_block *sb; /* pointer to VFS super block */
struct proc_dir_entry *s_proc; /* proc entry */
struct f2fs_super_block *raw_super; /* raw super block pointer */
+ struct mutex sb_lock; /* lock for raw super block */
int valid_super_block; /* valid super block no */
unsigned long s_flag; /* flags for sbi */
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ef362899df4e..f26a0bd17469 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1965,13 +1965,15 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file
*filp, unsigned long arg)
if (!f2fs_sb_has_encrypt(inode->i_sb))
return -EOPNOTSUPP;
- if (uuid_is_nonzero(sbi->raw_super->encrypt_pw_salt))
- goto got_it;
-
err = mnt_want_write_file(filp);
if (err)
return err;
+ mutex_lock(&sbi->sb_lock);
+
+ if (uuid_is_nonzero(sbi->raw_super->encrypt_pw_salt))
+ goto got_it;
+
/* update superblock with uuid */
generate_random_uuid(sbi->raw_super->encrypt_pw_salt);
@@ -1979,15 +1981,16 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file
*filp, unsigned long arg)
if (err) {
/* undo new data */
memset(sbi->raw_super->encrypt_pw_salt, 0, 16);
- mnt_drop_write_file(filp);
- return err;
+ goto out_err;
}
- mnt_drop_write_file(filp);
got_it:
if (copy_to_user((__u8 __user *)arg, sbi->raw_super->encrypt_pw_salt,
16))
- return -EFAULT;
- return 0;
+ err = -EFAULT;
+out_err:
+ mutex_unlock(&sbi->sb_lock);
+ mnt_drop_write_file(filp);
+ return err;
}
static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 52986c9cc677..1b49ad477dd9 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2232,6 +2232,8 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
sbi->dirty_device = 0;
spin_lock_init(&sbi->dev_lock);
+
+ mutex_init(&sbi->sb_lock);
}
static int init_percpu_info(struct f2fs_sb_info *sbi)
--
2.14.1.145.gb3622a4ee
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