[PATCH 1/2] f2fs: introduce sb_lock to make encrypt pwsalt update exclusive

[PATCH 1/2] f2fs: introduce sb_lock to make encrypt pwsalt update exclusive

[Chao Yu]

From: Chao Yu <yuchao0@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 <yuchao0@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

[PATCH 2/2] f2fs: expose extension_list sysfs entry

[Chao Yu]

From: Chao Yu <yuchao0@huawei.com>

This patch adds a sysfs entry 'extension_list' to support lookup/
add/delete item in extension list.

Lookup:
cat /sys/fs/f2fs/<device>/extentsion_list

Add:
echo 'extension' > /sys/fs/f2fs/<device>/extentsion_list

Delete:
echo '!extension' > /sys/fs/f2fs/<device>/extentsion_list

Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 fs/f2fs/f2fs.h          |  4 +++-
 fs/f2fs/file.c          |  4 ++--
 fs/f2fs/namei.c         | 42 +++++++++++++++++++++++++++++++++++++++---
 fs/f2fs/super.c         |  2 +-
 fs/f2fs/sysfs.c         | 40 ++++++++++++++++++++++++++++++++++++++++
 include/linux/f2fs_fs.h |  3 ++-
 6 files changed, 87 insertions(+), 8 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 0332c44a1d93..030436be2a35 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1048,7 +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 */
+	struct rw_semaphore sb_lock;		/* lock for raw super block */
 	int valid_super_block;			/* valid super block no */
 	unsigned long s_flag;				/* flags for sbi */
 
@@ -2612,6 +2612,8 @@ void handle_failed_inode(struct inode *inode);
 /*
  * namei.c
  */
+int update_extension_list(struct f2fs_sb_info *sbi, const char *name,
+								bool set);
 struct dentry *f2fs_get_parent(struct dentry *child);
 
 /*
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index f26a0bd17469..f64bcd0a7f73 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1969,7 +1969,7 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
 	if (err)
 		return err;
 
-	mutex_lock(&sbi->sb_lock);
+	down_write(&sbi->sb_lock);
 
 	if (uuid_is_nonzero(sbi->raw_super->encrypt_pw_salt))
 		goto got_it;
@@ -1988,7 +1988,7 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
 									16))
 		err = -EFAULT;
 out_err:
-	mutex_unlock(&sbi->sb_lock);
+	up_write(&sbi->sb_lock);
 	mnt_drop_write_file(filp);
 	return err;
 }
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index c4c94c7e9f4f..fa8e5c06ba39 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -171,16 +171,52 @@ static int is_multimedia_file(const unsigned char *s, const char *sub)
 static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
 		const unsigned char *name)
 {
-	int i;
-	__u8 (*extlist)[8] = sbi->raw_super->extension_list;
+	__u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
+	int i, count;
+
+	down_read(&sbi->sb_lock);
+
+	count = le32_to_cpu(sbi->raw_super->extension_count);
 
-	int count = le32_to_cpu(sbi->raw_super->extension_count);
 	for (i = 0; i < count; i++) {
 		if (is_multimedia_file(name, extlist[i])) {
 			file_set_cold(inode);
 			break;
 		}
 	}
+
+	up_read(&sbi->sb_lock);
+}
+
+int update_extension_list(struct f2fs_sb_info *sbi, const char *name, bool set)
+{
+	__u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
+	int count = le32_to_cpu(sbi->raw_super->extension_count);
+	int i;
+
+	for (i = 0; i < count; i++) {
+		if (strcmp(name, extlist[i]))
+			continue;
+
+		if (set)
+			return -EINVAL;
+
+		memcpy(extlist[i], extlist[i + 1],
+				F2FS_EXTENSION_LEN * (count - i - 1));
+		memset(extlist[count - 1], 0, F2FS_EXTENSION_LEN);
+		sbi->raw_super->extension_count = cpu_to_le32(count - 1);
+		return 0;
+	}
+
+	if (!set)
+		return -EINVAL;
+
+	if (count == F2FS_MAX_EXTENSION)
+		return -EINVAL;
+
+	strncpy(extlist[count], name, strlen(name));
+	sbi->raw_super->extension_count = cpu_to_le32(count + 1);
+	return 0;
 }
 
 static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 1b49ad477dd9..9b17355434f6 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2233,7 +2233,7 @@ 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);
+	init_rwsem(&sbi->sb_lock);
 }
 
 static int init_percpu_info(struct f2fs_sb_info *sbi)
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 374ee5c82f94..d27b28e602a6 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -136,6 +136,18 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
 	if (!ptr)
 		return -EINVAL;
 
+	if (!strcmp(a->attr.name, "extension_list")) {
+		__u8 (*extlist)[F2FS_EXTENSION_LEN] =
+					sbi->raw_super->extension_list;
+		int count = le32_to_cpu(sbi->raw_super->extension_count);
+		int len = 0, i;
+
+		for (i = 0; i < count; i++)
+			len += snprintf(buf + len, PAGE_SIZE - len, "%s\n",
+								extlist[i]);
+		return len;
+	}
+
 	ui = (unsigned int *)(ptr + a->offset);
 
 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
@@ -154,6 +166,32 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
 	if (!ptr)
 		return -EINVAL;
 
+	if (!strcmp(a->attr.name, "extension_list")) {
+		const char *name = strim((char *)buf);
+		bool set = true;
+
+		if (name[0] == '!') {
+			name++;
+			set = false;
+		}
+
+		if (strlen(name) >= F2FS_EXTENSION_LEN)
+			return -EINVAL;
+
+		down_write(&sbi->sb_lock);
+
+		ret = update_extension_list(sbi, name, set);
+		if (ret)
+			goto out;
+
+		ret = f2fs_commit_super(sbi, false);
+		if (ret)
+			update_extension_list(sbi, name, !set);
+out:
+		up_write(&sbi->sb_lock);
+		return ret ? ret : count;
+	}
+
 	ui = (unsigned int *)(ptr + a->offset);
 
 	ret = kstrtoul(skip_spaces(buf), 0, &t);
@@ -307,6 +345,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh, gc_pin_file_threshold);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_super_block, extension_list, extension_list);
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
 F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
@@ -357,6 +396,7 @@ static struct attribute *f2fs_attrs[] = {
 	ATTR_LIST(iostat_enable),
 	ATTR_LIST(readdir_ra),
 	ATTR_LIST(gc_pin_file_thresh),
+	ATTR_LIST(extension_list),
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 	ATTR_LIST(inject_rate),
 	ATTR_LIST(inject_type),
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index f7f09907e69d..3d03f51282ac 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -21,6 +21,7 @@
 #define F2FS_BLKSIZE			4096	/* support only 4KB block */
 #define F2FS_BLKSIZE_BITS		12	/* bits for F2FS_BLKSIZE */
 #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
+#define F2FS_EXTENSION_LEN		8	/* max size of extension */
 #define F2FS_BLK_ALIGN(x)	(((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)
 
 #define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
@@ -102,7 +103,7 @@ struct f2fs_super_block {
 	__u8 uuid[16];			/* 128-bit uuid for volume */
 	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
 	__le32 extension_count;		/* # of extensions below */
-	__u8 extension_list[F2FS_MAX_EXTENSION][8];	/* extension array */
+	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
 	__le32 cp_payload;
 	__u8 version[VERSION_LEN];	/* the kernel version */
 	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
-- 
2.14.1.145.gb3622a4ee

Re: [PATCH 2/2] f2fs: expose extension_list sysfs entry

[Jaegeuk Kim]

On 02/11, Chao Yu wrote:
> From: Chao Yu <yuchao0@huawei.com>
> 
> This patch adds a sysfs entry 'extension_list' to support lookup/
> add/delete item in extension list.

Hi Chao,

We need Doc change as well.

Thanks,

> 
> Lookup:
> cat /sys/fs/f2fs/<device>/extentsion_list
> 
> Add:
> echo 'extension' > /sys/fs/f2fs/<device>/extentsion_list
> 
> Delete:
> echo '!extension' > /sys/fs/f2fs/<device>/extentsion_list
> 
> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> ---
>  fs/f2fs/f2fs.h          |  4 +++-
>  fs/f2fs/file.c          |  4 ++--
>  fs/f2fs/namei.c         | 42 +++++++++++++++++++++++++++++++++++++++---
>  fs/f2fs/super.c         |  2 +-
>  fs/f2fs/sysfs.c         | 40 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/f2fs_fs.h |  3 ++-
>  6 files changed, 87 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 0332c44a1d93..030436be2a35 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -1048,7 +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 */
> +	struct rw_semaphore sb_lock;		/* lock for raw super block */
>  	int valid_super_block;			/* valid super block no */
>  	unsigned long s_flag;				/* flags for sbi */
>  
> @@ -2612,6 +2612,8 @@ void handle_failed_inode(struct inode *inode);
>  /*
>   * namei.c
>   */
> +int update_extension_list(struct f2fs_sb_info *sbi, const char *name,
> +								bool set);
>  struct dentry *f2fs_get_parent(struct dentry *child);
>  
>  /*
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index f26a0bd17469..f64bcd0a7f73 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -1969,7 +1969,7 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
>  	if (err)
>  		return err;
>  
> -	mutex_lock(&sbi->sb_lock);
> +	down_write(&sbi->sb_lock);
>  
>  	if (uuid_is_nonzero(sbi->raw_super->encrypt_pw_salt))
>  		goto got_it;
> @@ -1988,7 +1988,7 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
>  									16))
>  		err = -EFAULT;
>  out_err:
> -	mutex_unlock(&sbi->sb_lock);
> +	up_write(&sbi->sb_lock);
>  	mnt_drop_write_file(filp);
>  	return err;
>  }
> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
> index c4c94c7e9f4f..fa8e5c06ba39 100644
> --- a/fs/f2fs/namei.c
> +++ b/fs/f2fs/namei.c
> @@ -171,16 +171,52 @@ static int is_multimedia_file(const unsigned char *s, const char *sub)
>  static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
>  		const unsigned char *name)
>  {
> -	int i;
> -	__u8 (*extlist)[8] = sbi->raw_super->extension_list;
> +	__u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
> +	int i, count;
> +
> +	down_read(&sbi->sb_lock);
> +
> +	count = le32_to_cpu(sbi->raw_super->extension_count);
>  
> -	int count = le32_to_cpu(sbi->raw_super->extension_count);
>  	for (i = 0; i < count; i++) {
>  		if (is_multimedia_file(name, extlist[i])) {
>  			file_set_cold(inode);
>  			break;
>  		}
>  	}
> +
> +	up_read(&sbi->sb_lock);
> +}
> +
> +int update_extension_list(struct f2fs_sb_info *sbi, const char *name, bool set)
> +{
> +	__u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
> +	int count = le32_to_cpu(sbi->raw_super->extension_count);
> +	int i;
> +
> +	for (i = 0; i < count; i++) {
> +		if (strcmp(name, extlist[i]))
> +			continue;
> +
> +		if (set)
> +			return -EINVAL;
> +
> +		memcpy(extlist[i], extlist[i + 1],
> +				F2FS_EXTENSION_LEN * (count - i - 1));
> +		memset(extlist[count - 1], 0, F2FS_EXTENSION_LEN);
> +		sbi->raw_super->extension_count = cpu_to_le32(count - 1);
> +		return 0;
> +	}
> +
> +	if (!set)
> +		return -EINVAL;
> +
> +	if (count == F2FS_MAX_EXTENSION)
> +		return -EINVAL;
> +
> +	strncpy(extlist[count], name, strlen(name));
> +	sbi->raw_super->extension_count = cpu_to_le32(count + 1);
> +	return 0;
>  }
>  
>  static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 1b49ad477dd9..9b17355434f6 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2233,7 +2233,7 @@ 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);
> +	init_rwsem(&sbi->sb_lock);
>  }
>  
>  static int init_percpu_info(struct f2fs_sb_info *sbi)
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index 374ee5c82f94..d27b28e602a6 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -136,6 +136,18 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
>  	if (!ptr)
>  		return -EINVAL;
>  
> +	if (!strcmp(a->attr.name, "extension_list")) {
> +		__u8 (*extlist)[F2FS_EXTENSION_LEN] =
> +					sbi->raw_super->extension_list;
> +		int count = le32_to_cpu(sbi->raw_super->extension_count);
> +		int len = 0, i;
> +
> +		for (i = 0; i < count; i++)
> +			len += snprintf(buf + len, PAGE_SIZE - len, "%s\n",
> +								extlist[i]);
> +		return len;
> +	}
> +
>  	ui = (unsigned int *)(ptr + a->offset);
>  
>  	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
> @@ -154,6 +166,32 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
>  	if (!ptr)
>  		return -EINVAL;
>  
> +	if (!strcmp(a->attr.name, "extension_list")) {
> +		const char *name = strim((char *)buf);
> +		bool set = true;
> +
> +		if (name[0] == '!') {
> +			name++;
> +			set = false;
> +		}
> +
> +		if (strlen(name) >= F2FS_EXTENSION_LEN)
> +			return -EINVAL;
> +
> +		down_write(&sbi->sb_lock);
> +
> +		ret = update_extension_list(sbi, name, set);
> +		if (ret)
> +			goto out;
> +
> +		ret = f2fs_commit_super(sbi, false);
> +		if (ret)
> +			update_extension_list(sbi, name, !set);
> +out:
> +		up_write(&sbi->sb_lock);
> +		return ret ? ret : count;
> +	}
> +
>  	ui = (unsigned int *)(ptr + a->offset);
>  
>  	ret = kstrtoul(skip_spaces(buf), 0, &t);
> @@ -307,6 +345,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
>  F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
>  F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
>  F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh, gc_pin_file_threshold);
> +F2FS_RW_ATTR(F2FS_SBI, f2fs_super_block, extension_list, extension_list);
>  #ifdef CONFIG_F2FS_FAULT_INJECTION
>  F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
>  F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
> @@ -357,6 +396,7 @@ static struct attribute *f2fs_attrs[] = {
>  	ATTR_LIST(iostat_enable),
>  	ATTR_LIST(readdir_ra),
>  	ATTR_LIST(gc_pin_file_thresh),
> +	ATTR_LIST(extension_list),
>  #ifdef CONFIG_F2FS_FAULT_INJECTION
>  	ATTR_LIST(inject_rate),
>  	ATTR_LIST(inject_type),
> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> index f7f09907e69d..3d03f51282ac 100644
> --- a/include/linux/f2fs_fs.h
> +++ b/include/linux/f2fs_fs.h
> @@ -21,6 +21,7 @@
>  #define F2FS_BLKSIZE			4096	/* support only 4KB block */
>  #define F2FS_BLKSIZE_BITS		12	/* bits for F2FS_BLKSIZE */
>  #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
> +#define F2FS_EXTENSION_LEN		8	/* max size of extension */
>  #define F2FS_BLK_ALIGN(x)	(((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)
>  
>  #define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
> @@ -102,7 +103,7 @@ struct f2fs_super_block {
>  	__u8 uuid[16];			/* 128-bit uuid for volume */
>  	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
>  	__le32 extension_count;		/* # of extensions below */
> -	__u8 extension_list[F2FS_MAX_EXTENSION][8];	/* extension array */
> +	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
>  	__le32 cp_payload;
>  	__u8 version[VERSION_LEN];	/* the kernel version */
>  	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
> -- 
> 2.14.1.145.gb3622a4ee

Re: [PATCH 2/2] f2fs: expose extension_list sysfs entry

[Chao Yu]

Hi Jaegeuk,

On 2018/2/25 17:29, Jaegeuk Kim wrote:
> On 02/11, Chao Yu wrote:
>> From: Chao Yu <yuchao0@huawei.com>
>>
>> This patch adds a sysfs entry 'extension_list' to support lookup/
>> add/delete item in extension list.
> 
> Hi Chao,
> 
> We need Doc change as well.

Oh, right, let me add it.

Thanks,

> 
> Thanks,
> 
>>
>> Lookup:
>> cat /sys/fs/f2fs/<device>/extentsion_list
>>
>> Add:
>> echo 'extension' > /sys/fs/f2fs/<device>/extentsion_list
>>
>> Delete:
>> echo '!extension' > /sys/fs/f2fs/<device>/extentsion_list
>>
>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>> ---
>>  fs/f2fs/f2fs.h          |  4 +++-
>>  fs/f2fs/file.c          |  4 ++--
>>  fs/f2fs/namei.c         | 42 +++++++++++++++++++++++++++++++++++++++---
>>  fs/f2fs/super.c         |  2 +-
>>  fs/f2fs/sysfs.c         | 40 ++++++++++++++++++++++++++++++++++++++++
>>  include/linux/f2fs_fs.h |  3 ++-
>>  6 files changed, 87 insertions(+), 8 deletions(-)
>>
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index 0332c44a1d93..030436be2a35 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -1048,7 +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 */
>> +	struct rw_semaphore sb_lock;		/* lock for raw super block */
>>  	int valid_super_block;			/* valid super block no */
>>  	unsigned long s_flag;				/* flags for sbi */
>>  
>> @@ -2612,6 +2612,8 @@ void handle_failed_inode(struct inode *inode);
>>  /*
>>   * namei.c
>>   */
>> +int update_extension_list(struct f2fs_sb_info *sbi, const char *name,
>> +								bool set);
>>  struct dentry *f2fs_get_parent(struct dentry *child);
>>  
>>  /*
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>> index f26a0bd17469..f64bcd0a7f73 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -1969,7 +1969,7 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
>>  	if (err)
>>  		return err;
>>  
>> -	mutex_lock(&sbi->sb_lock);
>> +	down_write(&sbi->sb_lock);
>>  
>>  	if (uuid_is_nonzero(sbi->raw_super->encrypt_pw_salt))
>>  		goto got_it;
>> @@ -1988,7 +1988,7 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
>>  									16))
>>  		err = -EFAULT;
>>  out_err:
>> -	mutex_unlock(&sbi->sb_lock);
>> +	up_write(&sbi->sb_lock);
>>  	mnt_drop_write_file(filp);
>>  	return err;
>>  }
>> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
>> index c4c94c7e9f4f..fa8e5c06ba39 100644
>> --- a/fs/f2fs/namei.c
>> +++ b/fs/f2fs/namei.c
>> @@ -171,16 +171,52 @@ static int is_multimedia_file(const unsigned char *s, const char *sub)
>>  static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
>>  		const unsigned char *name)
>>  {
>> -	int i;
>> -	__u8 (*extlist)[8] = sbi->raw_super->extension_list;
>> +	__u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
>> +	int i, count;
>> +
>> +	down_read(&sbi->sb_lock);
>> +
>> +	count = le32_to_cpu(sbi->raw_super->extension_count);
>>  
>> -	int count = le32_to_cpu(sbi->raw_super->extension_count);
>>  	for (i = 0; i < count; i++) {
>>  		if (is_multimedia_file(name, extlist[i])) {
>>  			file_set_cold(inode);
>>  			break;
>>  		}
>>  	}
>> +
>> +	up_read(&sbi->sb_lock);
>> +}
>> +
>> +int update_extension_list(struct f2fs_sb_info *sbi, const char *name, bool set)
>> +{
>> +	__u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
>> +	int count = le32_to_cpu(sbi->raw_super->extension_count);
>> +	int i;
>> +
>> +	for (i = 0; i < count; i++) {
>> +		if (strcmp(name, extlist[i]))
>> +			continue;
>> +
>> +		if (set)
>> +			return -EINVAL;
>> +
>> +		memcpy(extlist[i], extlist[i + 1],
>> +				F2FS_EXTENSION_LEN * (count - i - 1));
>> +		memset(extlist[count - 1], 0, F2FS_EXTENSION_LEN);
>> +		sbi->raw_super->extension_count = cpu_to_le32(count - 1);
>> +		return 0;
>> +	}
>> +
>> +	if (!set)
>> +		return -EINVAL;
>> +
>> +	if (count == F2FS_MAX_EXTENSION)
>> +		return -EINVAL;
>> +
>> +	strncpy(extlist[count], name, strlen(name));
>> +	sbi->raw_super->extension_count = cpu_to_le32(count + 1);
>> +	return 0;
>>  }
>>  
>>  static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>> index 1b49ad477dd9..9b17355434f6 100644
>> --- a/fs/f2fs/super.c
>> +++ b/fs/f2fs/super.c
>> @@ -2233,7 +2233,7 @@ 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);
>> +	init_rwsem(&sbi->sb_lock);
>>  }
>>  
>>  static int init_percpu_info(struct f2fs_sb_info *sbi)
>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
>> index 374ee5c82f94..d27b28e602a6 100644
>> --- a/fs/f2fs/sysfs.c
>> +++ b/fs/f2fs/sysfs.c
>> @@ -136,6 +136,18 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
>>  	if (!ptr)
>>  		return -EINVAL;
>>  
>> +	if (!strcmp(a->attr.name, "extension_list")) {
>> +		__u8 (*extlist)[F2FS_EXTENSION_LEN] =
>> +					sbi->raw_super->extension_list;
>> +		int count = le32_to_cpu(sbi->raw_super->extension_count);
>> +		int len = 0, i;
>> +
>> +		for (i = 0; i < count; i++)
>> +			len += snprintf(buf + len, PAGE_SIZE - len, "%s\n",
>> +								extlist[i]);
>> +		return len;
>> +	}
>> +
>>  	ui = (unsigned int *)(ptr + a->offset);
>>  
>>  	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
>> @@ -154,6 +166,32 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
>>  	if (!ptr)
>>  		return -EINVAL;
>>  
>> +	if (!strcmp(a->attr.name, "extension_list")) {
>> +		const char *name = strim((char *)buf);
>> +		bool set = true;
>> +
>> +		if (name[0] == '!') {
>> +			name++;
>> +			set = false;
>> +		}
>> +
>> +		if (strlen(name) >= F2FS_EXTENSION_LEN)
>> +			return -EINVAL;
>> +
>> +		down_write(&sbi->sb_lock);
>> +
>> +		ret = update_extension_list(sbi, name, set);
>> +		if (ret)
>> +			goto out;
>> +
>> +		ret = f2fs_commit_super(sbi, false);
>> +		if (ret)
>> +			update_extension_list(sbi, name, !set);
>> +out:
>> +		up_write(&sbi->sb_lock);
>> +		return ret ? ret : count;
>> +	}
>> +
>>  	ui = (unsigned int *)(ptr + a->offset);
>>  
>>  	ret = kstrtoul(skip_spaces(buf), 0, &t);
>> @@ -307,6 +345,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
>>  F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
>>  F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
>>  F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh, gc_pin_file_threshold);
>> +F2FS_RW_ATTR(F2FS_SBI, f2fs_super_block, extension_list, extension_list);
>>  #ifdef CONFIG_F2FS_FAULT_INJECTION
>>  F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
>>  F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
>> @@ -357,6 +396,7 @@ static struct attribute *f2fs_attrs[] = {
>>  	ATTR_LIST(iostat_enable),
>>  	ATTR_LIST(readdir_ra),
>>  	ATTR_LIST(gc_pin_file_thresh),
>> +	ATTR_LIST(extension_list),
>>  #ifdef CONFIG_F2FS_FAULT_INJECTION
>>  	ATTR_LIST(inject_rate),
>>  	ATTR_LIST(inject_type),
>> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
>> index f7f09907e69d..3d03f51282ac 100644
>> --- a/include/linux/f2fs_fs.h
>> +++ b/include/linux/f2fs_fs.h
>> @@ -21,6 +21,7 @@
>>  #define F2FS_BLKSIZE			4096	/* support only 4KB block */
>>  #define F2FS_BLKSIZE_BITS		12	/* bits for F2FS_BLKSIZE */
>>  #define F2FS_MAX_EXTENSION		64	/* # of extension entries */
>> +#define F2FS_EXTENSION_LEN		8	/* max size of extension */
>>  #define F2FS_BLK_ALIGN(x)	(((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)
>>  
>>  #define NULL_ADDR		((block_t)0)	/* used as block_t addresses */
>> @@ -102,7 +103,7 @@ struct f2fs_super_block {
>>  	__u8 uuid[16];			/* 128-bit uuid for volume */
>>  	__le16 volume_name[MAX_VOLUME_NAME];	/* volume name */
>>  	__le32 extension_count;		/* # of extensions below */
>> -	__u8 extension_list[F2FS_MAX_EXTENSION][8];	/* extension array */
>> +	__u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
>>  	__le32 cp_payload;
>>  	__u8 version[VERSION_LEN];	/* the kernel version */
>>  	__u8 init_version[VERSION_LEN];	/* the initial kernel version */
>> -- 
>> 2.14.1.145.gb3622a4ee
> 
> .
>