[FOR INTERNAL REVIEW] [PATCH 4/4] staging: erofs: update .mount and .remount_sb

[Gao Xiang]

Hi David,

On 2018/7/31 15:38, Chao Yu wrote:
> Hi David,
> 
> Could you please help to check this patch as well?
> 

If you don't mind seeing more code, the patched code of super/inode.c can also be accessed at

https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git/tree/drivers/staging/erofs/super.c?h=erofs-dev
https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git/tree/drivers/staging/erofs/inode.c?h=erofs-dev

It will be of great help...Thank you..

Thanks,
Gao Xiang

> Thanks,
> 
> On 2018/7/30 17:18, Gao Xiang wrote:
>> This patch updates .mount and .remount_sb after
>> commit 286c6b145729 ("vfs: Require specification
>> of size of mount data for internal mounts").
>>
>> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
>> ---
>>
>> - Tested with images generated by mkfs.erofs:
>>    1) mount and unmount operations
>>    2) md5sum `find . -type f`
>>
>>  drivers/staging/erofs/internal.h |  1 -
>>  drivers/staging/erofs/super.c    | 61 +++++++++++-----------------------------
>>  2 files changed, 16 insertions(+), 46 deletions(-)
>>
>> diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
>> index 367b39f..9074a56 100644
>> --- a/drivers/staging/erofs/internal.h
>> +++ b/drivers/staging/erofs/internal.h
>> @@ -111,7 +111,6 @@ struct erofs_sb_info {
>>  
>>  	u8 uuid[16];                    /* 128-bit uuid for volume */
>>  	u8 volume_name[16];             /* volume name */
>> -	char *dev_name;
>>  
>>  	unsigned int mount_opt;
>>  	unsigned int shrinker_run_no;
>> diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
>> index ae1eb20..190a538 100644
>> --- a/drivers/staging/erofs/super.c
>> +++ b/drivers/staging/erofs/super.c
>> @@ -313,14 +313,18 @@ static struct inode *erofs_init_managed_cache(struct super_block *sb)
>>  
>>  #endif
>>  
>> -static int erofs_read_super(struct super_block *sb,
>> -	const char *dev_name, void *data, int silent)
>> +static int erofs_read_super(struct super_block *sb, void *data,
>> +			    size_t data_size, int silent)
>>  {
>>  	struct inode *inode;
>>  	struct erofs_sb_info *sbi;
>> +	char b[BDEVNAME_SIZE];
>>  	int err = -EINVAL;
>>  
>> -	infoln("read_super, device -> %s", dev_name);
>> +	/* get the block device name */
>> +	bdevname(sb->s_bdev, b);
>> +
>> +	infoln("read_super, device -> %s", b);
>>  	infoln("options -> %s", (char *)data);
>>  
>>  	if (unlikely(!sb_set_blocksize(sb, EROFS_BLKSIZ))) {
>> @@ -392,16 +396,6 @@ static int erofs_read_super(struct super_block *sb,
>>  		goto err_makeroot;
>>  	}
>>  
>> -	/* save the device name to sbi */
>> -	sbi->dev_name = __getname();
>> -	if (sbi->dev_name == NULL) {
>> -		err = -ENOMEM;
>> -		goto err_devname;
>> -	}
>> -
>> -	snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
>> -	sbi->dev_name[PATH_MAX - 1] = '\0';
>> -
>>  	erofs_register_super(sb);
>>  
>>  	/*
>> @@ -411,15 +405,13 @@ static int erofs_read_super(struct super_block *sb,
>>  	d_rehash(sb->s_root);
>>  
>>  	if (!silent)
>> -		infoln("mounted on %s with opts: %s.", dev_name,
>> -			(char *)data);
>> +		infoln("mounted on %s with opts: %s.", b, (char *)data);
>>  	return 0;
>>  	/*
>>  	 * please add a label for each exit point and use
>>  	 * the following name convention, thus new features
>>  	 * can be integrated easily without renaming labels.
>>  	 */
>> -err_devname:
>>  	dput(sb->s_root);
>>  err_makeroot:
>>  err_isdir:
>> @@ -445,6 +437,7 @@ static int erofs_read_super(struct super_block *sb,
>>  static void erofs_put_super(struct super_block *sb)
>>  {
>>  	struct erofs_sb_info *sbi = EROFS_SB(sb);
>> +	char b[BDEVNAME_SIZE];
>>  
>>  	/* for cases which are failed in "read_super" */
>>  	if (sbi == NULL)
>> @@ -452,8 +445,7 @@ static void erofs_put_super(struct super_block *sb)
>>  
>>  	WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
>>  
>> -	infoln("unmounted for %s", sbi->dev_name);
>> -	__putname(sbi->dev_name);
>> +	infoln("unmounted for %s", bdevname(sb->s_bdev, b));
>>  
>>  #ifdef EROFS_FS_HAS_MANAGED_CACHE
>>  	iput(sbi->managed_cache);
>> @@ -472,33 +464,11 @@ static void erofs_put_super(struct super_block *sb)
>>  	sb->s_fs_info = NULL;
>>  }
>>  
>> -
>> -struct erofs_mount_private {
>> -	const char *dev_name;
>> -	char *options;
>> -};
>> -
>> -/* support mount_bdev() with options */
>> -static int erofs_fill_super(struct super_block *sb,
>> -	void *_priv, int silent)
>> -{
>> -	struct erofs_mount_private *priv = _priv;
>> -
>> -	return erofs_read_super(sb, priv->dev_name,
>> -		priv->options, silent);
>> -}
>> -
>> -static struct dentry *erofs_mount(
>> -	struct file_system_type *fs_type, int flags,
>> -	const char *dev_name, void *data)
>> +static struct dentry *erofs_mount(struct file_system_type *fs_type, int flags,
>> +	const char *dev_name, void *data, size_t data_size)
>>  {
>> -	struct erofs_mount_private priv = {
>> -		.dev_name = dev_name,
>> -		.options = data
>> -	};
>> -
>> -	return mount_bdev(fs_type, flags, dev_name,
>> -		&priv, erofs_fill_super);
>> +	return mount_bdev(fs_type, flags, dev_name, data, data_size,
>> +		erofs_read_super);
>>  }
>>  
>>  static void erofs_kill_sb(struct super_block *sb)
>> @@ -623,7 +593,8 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root)
>>  	return 0;
>>  }
>>  
>> -static int erofs_remount(struct super_block *sb, int *flags, char *data)
>> +static int erofs_remount(struct super_block *sb, int *flags,
>> +	char *data, size_t data_size)
>>  {
>>  	BUG_ON(!sb_rdonly(sb));
>>  
>>
>