[v4] erofs: Add support for FS_IOC_GETFSLABEL

[PATCH v4] erofs: Add support for FS_IOC_GETFSLABEL

Posted by Bo Liu 1 week, 2 days ago

From: Bo Liu (OpenAnolis) <liubo03@inspur.com>

Add support for reading to the erofs volume label from the
FS_IOC_GETFSLABEL ioctls.

Signed-off-by: Bo Liu (OpenAnolis) <liubo03@inspur.com>
---

v1: https://lore.kernel.org/linux-erofs/20250825120617.19746-1-liubo03@inspur.com/
v2: https://lore.kernel.org/linux-erofs/20250826103926.4424-1-liubo03@inspur.com/
v3: https://lore.kernel.org/linux-erofs/20250920060455.24002-1-liubo03@inspur.com/

change since v3:
- move functions into inode.
- remove useless comment.

 fs/erofs/data.c     |  4 ++++
 fs/erofs/dir.c      |  4 ++++
 fs/erofs/inode.c    | 40 ++++++++++++++++++++++++++++++++++++----
 fs/erofs/internal.h |  6 ++++++
 fs/erofs/super.c    |  8 ++++++++
 5 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 3b1ba571c728..8ca29962a3dd 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -475,6 +475,10 @@ static loff_t erofs_file_llseek(struct file *file, loff_t offset, int whence)
 const struct file_operations erofs_file_fops = {
 	.llseek		= erofs_file_llseek,
 	.read_iter	= erofs_file_read_iter,
+	.unlocked_ioctl = erofs_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = erofs_compat_ioctl,
+#endif
 	.mmap_prepare	= erofs_file_mmap_prepare,
 	.get_unmapped_area = thp_get_unmapped_area,
 	.splice_read	= filemap_splice_read,
diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c
index debf469ad6bd..32b4f5aa60c9 100644
--- a/fs/erofs/dir.c
+++ b/fs/erofs/dir.c
@@ -123,4 +123,8 @@ const struct file_operations erofs_dir_fops = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.iterate_shared	= erofs_readdir,
+	.unlocked_ioctl = erofs_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = erofs_compat_ioctl,
+#endif
 };
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 9a2f59721522..7a9a9081f890 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -213,10 +213,7 @@ static int erofs_fill_inode(struct inode *inode)
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFREG:
 		inode->i_op = &erofs_generic_iops;
-		if (erofs_inode_is_data_compressed(vi->datalayout))
-			inode->i_fop = &generic_ro_fops;
-		else
-			inode->i_fop = &erofs_file_fops;
+		inode->i_fop = &erofs_file_fops;
 		break;
 	case S_IFDIR:
 		inode->i_op = &erofs_dir_iops;
@@ -341,6 +338,41 @@ int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
 	return 0;
 }
 
+static int erofs_ioctl_get_volume_label(struct inode *inode, void __user *arg)
+{
+	struct erofs_sb_info *sbi = EROFS_I_SB(inode);
+	int ret;
+
+	if (!sbi->volume_name)
+		ret = clear_user(arg, 1);
+	else
+		ret = copy_to_user(arg, sbi->volume_name,
+				   strlen(sbi->volume_name));
+
+	return ret ? -EFAULT : 0;
+}
+
+long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	void __user *argp = (void __user *)arg;
+
+	switch (cmd) {
+	case FS_IOC_GETFSLABEL:
+		return erofs_ioctl_get_volume_label(inode, argp);
+	default:
+		return -ENOTTY;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
+			unsigned long arg)
+{
+	return erofs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
 const struct inode_operations erofs_generic_iops = {
 	.getattr = erofs_getattr,
 	.listxattr = erofs_listxattr,
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 4ccc5f0ee8df..b70902e00586 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -166,6 +166,8 @@ struct erofs_sb_info {
 	struct erofs_domain *domain;
 	char *fsid;
 	char *domain_id;
+
+	char *volume_name;
 };
 
 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
@@ -535,6 +537,10 @@ static inline struct bio *erofs_fscache_bio_alloc(struct erofs_map_dev *mdev) {
 static inline void erofs_fscache_submit_bio(struct bio *bio) {}
 #endif
 
+long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
+long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
+			unsigned long arg);
+
 #define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
 
 #endif	/* __EROFS_INTERNAL_H */
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 1b529ace4db0..f1535ebe03ec 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -343,6 +343,13 @@ static int erofs_read_superblock(struct super_block *sb)
 	sbi->fixed_nsec = le32_to_cpu(dsb->fixed_nsec);
 	super_set_uuid(sb, (void *)dsb->uuid, sizeof(dsb->uuid));
 
+	if (dsb->volume_name[0]) {
+		sbi->volume_name = kstrndup(dsb->volume_name,
+					    sizeof(dsb->volume_name), GFP_KERNEL);
+		if (!sbi->volume_name)
+			return -ENOMEM;
+	}
+
 	/* parse on-disk compression configurations */
 	ret = z_erofs_parse_cfgs(sb, dsb);
 	if (ret < 0)
@@ -822,6 +829,7 @@ static void erofs_sb_free(struct erofs_sb_info *sbi)
 	kfree(sbi->domain_id);
 	if (sbi->dif0.file)
 		fput(sbi->dif0.file);
+	kfree(sbi->volume_name);
 	kfree(sbi);
 }
 
-- 
2.31.1

Re: [PATCH v4] erofs: Add support for FS_IOC_GETFSLABEL

Posted by kernel test robot 1 week, 2 days ago

Hi Bo,

kernel test robot noticed the following build errors:

[auto build test ERROR on xiang-erofs/dev-test]
[also build test ERROR on xiang-erofs/dev xiang-erofs/fixes linus/master v6.17-rc7 next-20250922]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Bo-Liu/erofs-Add-support-for-FS_IOC_GETFSLABEL/20250922-173127
base:   https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev-test
patch link:    https://lore.kernel.org/r/20250922092937.2055-1-liubo03%40inspur.com
patch subject: [PATCH v4] erofs: Add support for FS_IOC_GETFSLABEL
config: sparc64-randconfig-001-20250923 (https://download.01.org/0day-ci/archive/20250923/202509231033.ADjNYvqL-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project cafc064fc7a96b3979a023ddae1da2b499d6c954)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250923/202509231033.ADjNYvqL-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509231033.ADjNYvqL-lkp@intel.com/

All errors (new ones prefixed by >>):

>> fs/erofs/inode.c:372:47: error: call to undeclared function 'compat_ptr'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     372 |         return erofs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
         |                                                      ^
   1 error generated.


vim +/compat_ptr +372 fs/erofs/inode.c

   367	
   368	#ifdef CONFIG_COMPAT
   369	long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
   370				unsigned long arg)
   371	{
 > 372		return erofs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
   373	}
   374	#endif
   375	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v4] erofs: Add support for FS_IOC_GETFSLABEL

Posted by Chao Yu 1 week, 2 days ago

On 9/22/25 17:29, Bo Liu wrote:
> From: Bo Liu (OpenAnolis) <liubo03@inspur.com>
> 
> Add support for reading to the erofs volume label from the
> FS_IOC_GETFSLABEL ioctls.
> 
> Signed-off-by: Bo Liu (OpenAnolis) <liubo03@inspur.com>
> ---
> 
> v1: https://lore.kernel.org/linux-erofs/20250825120617.19746-1-liubo03@inspur.com/
> v2: https://lore.kernel.org/linux-erofs/20250826103926.4424-1-liubo03@inspur.com/
> v3: https://lore.kernel.org/linux-erofs/20250920060455.24002-1-liubo03@inspur.com/
> 
> change since v3:
> - move functions into inode.
> - remove useless comment.
> 
>  fs/erofs/data.c     |  4 ++++
>  fs/erofs/dir.c      |  4 ++++
>  fs/erofs/inode.c    | 40 ++++++++++++++++++++++++++++++++++++----
>  fs/erofs/internal.h |  6 ++++++
>  fs/erofs/super.c    |  8 ++++++++
>  5 files changed, 58 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/erofs/data.c b/fs/erofs/data.c
> index 3b1ba571c728..8ca29962a3dd 100644
> --- a/fs/erofs/data.c
> +++ b/fs/erofs/data.c
> @@ -475,6 +475,10 @@ static loff_t erofs_file_llseek(struct file *file, loff_t offset, int whence)
>  const struct file_operations erofs_file_fops = {
>  	.llseek		= erofs_file_llseek,
>  	.read_iter	= erofs_file_read_iter,
> +	.unlocked_ioctl = erofs_ioctl,
> +#ifdef CONFIG_COMPAT
> +	.compat_ioctl   = erofs_compat_ioctl,
> +#endif
>  	.mmap_prepare	= erofs_file_mmap_prepare,
>  	.get_unmapped_area = thp_get_unmapped_area,
>  	.splice_read	= filemap_splice_read,
> diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c
> index debf469ad6bd..32b4f5aa60c9 100644
> --- a/fs/erofs/dir.c
> +++ b/fs/erofs/dir.c
> @@ -123,4 +123,8 @@ const struct file_operations erofs_dir_fops = {
>  	.llseek		= generic_file_llseek,
>  	.read		= generic_read_dir,
>  	.iterate_shared	= erofs_readdir,
> +	.unlocked_ioctl = erofs_ioctl,
> +#ifdef CONFIG_COMPAT
> +	.compat_ioctl   = erofs_compat_ioctl,
> +#endif
>  };
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index 9a2f59721522..7a9a9081f890 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -213,10 +213,7 @@ static int erofs_fill_inode(struct inode *inode)
>  	switch (inode->i_mode & S_IFMT) {
>  	case S_IFREG:
>  		inode->i_op = &erofs_generic_iops;
> -		if (erofs_inode_is_data_compressed(vi->datalayout))
> -			inode->i_fop = &generic_ro_fops;
> -		else
> -			inode->i_fop = &erofs_file_fops;
> +		inode->i_fop = &erofs_file_fops;
>  		break;
>  	case S_IFDIR:
>  		inode->i_op = &erofs_dir_iops;
> @@ -341,6 +338,41 @@ int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
>  	return 0;
>  }
>  
> +static int erofs_ioctl_get_volume_label(struct inode *inode, void __user *arg)
> +{
> +	struct erofs_sb_info *sbi = EROFS_I_SB(inode);
> +	int ret;
> +
> +	if (!sbi->volume_name)
> +		ret = clear_user(arg, 1);
> +	else
> +		ret = copy_to_user(arg, sbi->volume_name,
> +				   strlen(sbi->volume_name));
> +
> +	return ret ? -EFAULT : 0;
> +}
> +
> +long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> +{
> +	struct inode *inode = file_inode(filp);
> +	void __user *argp = (void __user *)arg;
> +
> +	switch (cmd) {
> +	case FS_IOC_GETFSLABEL:
> +		return erofs_ioctl_get_volume_label(inode, argp);
> +	default:
> +		return -ENOTTY;
> +	}
> +}
> +
> +#ifdef CONFIG_COMPAT
> +long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
> +			unsigned long arg)
> +{
> +	return erofs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
> +}
> +#endif
> +
>  const struct inode_operations erofs_generic_iops = {
>  	.getattr = erofs_getattr,
>  	.listxattr = erofs_listxattr,
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index 4ccc5f0ee8df..b70902e00586 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -166,6 +166,8 @@ struct erofs_sb_info {
>  	struct erofs_domain *domain;
>  	char *fsid;
>  	char *domain_id;
> +
> +	char *volume_name;
>  };
>  
>  #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
> @@ -535,6 +537,10 @@ static inline struct bio *erofs_fscache_bio_alloc(struct erofs_map_dev *mdev) {
>  static inline void erofs_fscache_submit_bio(struct bio *bio) {}
>  #endif
>  
> +long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);

#ifdef CONFIG_COMPAT

> +long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
> +			unsigned long arg);

#endif

Thanks,

> +
>  #define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
>  
>  #endif	/* __EROFS_INTERNAL_H */
> diff --git a/fs/erofs/super.c b/fs/erofs/super.c
> index 1b529ace4db0..f1535ebe03ec 100644
> --- a/fs/erofs/super.c
> +++ b/fs/erofs/super.c
> @@ -343,6 +343,13 @@ static int erofs_read_superblock(struct super_block *sb)
>  	sbi->fixed_nsec = le32_to_cpu(dsb->fixed_nsec);
>  	super_set_uuid(sb, (void *)dsb->uuid, sizeof(dsb->uuid));
>  
> +	if (dsb->volume_name[0]) {
> +		sbi->volume_name = kstrndup(dsb->volume_name,
> +					    sizeof(dsb->volume_name), GFP_KERNEL);
> +		if (!sbi->volume_name)
> +			return -ENOMEM;
> +	}
> +
>  	/* parse on-disk compression configurations */
>  	ret = z_erofs_parse_cfgs(sb, dsb);
>  	if (ret < 0)
> @@ -822,6 +829,7 @@ static void erofs_sb_free(struct erofs_sb_info *sbi)
>  	kfree(sbi->domain_id);
>  	if (sbi->dif0.file)
>  		fput(sbi->dif0.file);
> +	kfree(sbi->volume_name);
>  	kfree(sbi);
>  }
>

Re: [PATCH v4] erofs: Add support for FS_IOC_GETFSLABEL

Posted by Gao Xiang 1 week, 2 days ago

Hi Chao,

On 2025/9/23 10:23, Chao Yu wrote:
> On 9/22/25 17:29, Bo Liu wrote:
>> From: Bo Liu (OpenAnolis) <liubo03@inspur.com>
>>
>> Add support for reading to the erofs volume label from the
>> FS_IOC_GETFSLABEL ioctls.
>>
>> Signed-off-by: Bo Liu (OpenAnolis) <liubo03@inspur.com>
>> ---

...

>>   
>> +long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
> 
> #ifdef CONFIG_COMPAT
> 
>> +long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
>> +			unsigned long arg);

Since it's a function declaration, when CONFIG_COMPAT is not defined,
there is no user to use erofs_compat_ioctl(), so I think it is fine
to just leave the declaration here?

Thanks,
Gao Xiang

> 
> #endif
> 
> Thanks,
> 
>> +
>

Re: [PATCH v4] erofs: Add support for FS_IOC_GETFSLABEL

Posted by Chao Yu 1 week, 2 days ago

On 9/23/25 10:34, Gao Xiang wrote:
> Hi Chao,
> 
> On 2025/9/23 10:23, Chao Yu wrote:
>> On 9/22/25 17:29, Bo Liu wrote:
>>> From: Bo Liu (OpenAnolis) <liubo03@inspur.com>
>>>
>>> Add support for reading to the erofs volume label from the
>>> FS_IOC_GETFSLABEL ioctls.
>>>
>>> Signed-off-by: Bo Liu (OpenAnolis) <liubo03@inspur.com>
>>> ---
> 
> ...
> 
>>>   +long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
>>
>> #ifdef CONFIG_COMPAT
>>
>>> +long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
>>> +            unsigned long arg);
> 
> Since it's a function declaration, when CONFIG_COMPAT is not defined,
> there is no user to use erofs_compat_ioctl(), so I think it is fine
> to just leave the declaration here?

Xiang,

Sure, it won't affect compile and link, we can leave it as it is since it's trivial.

Thanks,

> 
> Thanks,
> Gao Xiang
> 
>>
>> #endif
>>
>> Thanks,
>>
>>> +
>>
> 
>

Re: [PATCH v4] erofs: Add support for FS_IOC_GETFSLABEL

Posted by Gao Xiang 1 week, 2 days ago


On 2025/9/23 10:59, Chao Yu wrote:
> On 9/23/25 10:34, Gao Xiang wrote:
>> Hi Chao,
>>
>> On 2025/9/23 10:23, Chao Yu wrote:
>>> On 9/22/25 17:29, Bo Liu wrote:
>>>> From: Bo Liu (OpenAnolis) <liubo03@inspur.com>
>>>>
>>>> Add support for reading to the erofs volume label from the
>>>> FS_IOC_GETFSLABEL ioctls.
>>>>
>>>> Signed-off-by: Bo Liu (OpenAnolis) <liubo03@inspur.com>
>>>> ---
>>
>> ...
>>
>>>>    +long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
>>>
>>> #ifdef CONFIG_COMPAT
>>>
>>>> +long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
>>>> +            unsigned long arg);
>>
>> Since it's a function declaration, when CONFIG_COMPAT is not defined,
>> there is no user to use erofs_compat_ioctl(), so I think it is fine
>> to just leave the declaration here?
> 
> Xiang,
> 
> Sure, it won't affect compile and link, we can leave it as it is since it's trivial.

Yeah, my preference is to avoid unnecessary #ifdef if possible,
anyway (since unused function declarations won't affect anything..)

Thanks,
Gao Xiang

> 
> Thanks,
> 
>>
>> Thanks,
>> Gao Xiang
>>
>>>
>>> #endif
>>>
>>> Thanks,
>>>
>>>> +
>>>
>>
>>

Re: [PATCH v4] erofs: Add support for FS_IOC_GETFSLABEL

Posted by Gao Xiang 1 week, 2 days ago


On 2025/9/22 17:29, Bo Liu wrote:
> From: Bo Liu (OpenAnolis) <liubo03@inspur.com>
> 
> Add support for reading to the erofs volume label from the
> FS_IOC_GETFSLABEL ioctls.
> 
> Signed-off-by: Bo Liu (OpenAnolis) <liubo03@inspur.com>

Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Thanks,
Gao Xiang