From: Gao Xiang <hsiangkao@linux.alibaba.com>

  - Move the `struct erofs_anon_fs_type` to super.c and expose it
    in preparation for the upcoming page cache share feature;

  - Remove the `.owner` field, as they are all internal mounts and
    fully managed by EROFS.  Retaining `.owner` would unnecessarily
    increment module reference counts, preventing the EROFS kernel
    module from being unloaded.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
 fs/erofs/fscache.c  | 13 -------------
 fs/erofs/internal.h |  2 ++
 fs/erofs/super.c    | 14 ++++++++++++++
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index 7a346e20f7b7..f4937b025038 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -3,7 +3,6 @@
  * Copyright (C) 2022, Alibaba Cloud
  * Copyright (C) 2022, Bytedance Inc. All rights reserved.
  */
-#include <linux/pseudo_fs.h>
 #include <linux/fscache.h>
 #include "internal.h"
 
@@ -13,18 +12,6 @@ static LIST_HEAD(erofs_domain_list);
 static LIST_HEAD(erofs_domain_cookies_list);
 static struct vfsmount *erofs_pseudo_mnt;
 
-static int erofs_anon_init_fs_context(struct fs_context *fc)
-{
-	return init_pseudo(fc, EROFS_SUPER_MAGIC) ? 0 : -ENOMEM;
-}
-
-static struct file_system_type erofs_anon_fs_type = {
-	.owner		= THIS_MODULE,
-	.name           = "pseudo_erofs",
-	.init_fs_context = erofs_anon_init_fs_context,
-	.kill_sb        = kill_anon_super,
-};
-
 struct erofs_fscache_io {
 	struct netfs_cache_resources cres;
 	struct iov_iter		iter;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index f7f622836198..98fe652aea33 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -188,6 +188,8 @@ static inline bool erofs_is_fileio_mode(struct erofs_sb_info *sbi)
 	return IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) && sbi->dif0.file;
 }
 
+extern struct file_system_type erofs_anon_fs_type;
+
 static inline bool erofs_is_fscache_mode(struct super_block *sb)
 {
 	return IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) &&
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 937a215f626c..f18f43b78fca 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -11,6 +11,7 @@
 #include <linux/fs_parser.h>
 #include <linux/exportfs.h>
 #include <linux/backing-dev.h>
+#include <linux/pseudo_fs.h>
 #include "xattr.h"
 
 #define CREATE_TRACE_POINTS
@@ -936,6 +937,19 @@ static struct file_system_type erofs_fs_type = {
 };
 MODULE_ALIAS_FS("erofs");
 
+#if defined(CONFIG_EROFS_FS_ONDEMAND)
+static int erofs_anon_init_fs_context(struct fs_context *fc)
+{
+	return init_pseudo(fc, EROFS_SUPER_MAGIC) ? 0 : -ENOMEM;
+}
+
+struct file_system_type erofs_anon_fs_type = {
+	.name           = "pseudo_erofs",
+	.init_fs_context = erofs_anon_init_fs_context,
+	.kill_sb        = kill_anon_super,
+};
+#endif
+
 static int __init erofs_module_init(void)
 {
 	int err;
-- 
2.22.0

> +#if defined(CONFIG_EROFS_FS_ONDEMAND)

Normally this would just use #ifdef.

Hi, Xiang

On 2026/1/16 23:38, Christoph Hellwig wrote:
>> +#if defined(CONFIG_EROFS_FS_ONDEMAND)
> 
> Normally this would just use #ifdef.
> 
How about using #ifdef for all of them? I checked and there are only 
three places in total, and all of them are related to 
FS_PAGE_CACHE_SHARE or FS_ONDEMAND config macro.

Thanks,
Hongbo

On 2026/1/19 09:34, Hongbo Li wrote:
> Hi, Xiang
> 
> On 2026/1/16 23:38, Christoph Hellwig wrote:
>>> +#if defined(CONFIG_EROFS_FS_ONDEMAND)
>>
>> Normally this would just use #ifdef.
>>
> How about using #ifdef for all of them? I checked and there are only three places in total, and all of them are related to FS_PAGE_CACHE_SHARE or FS_ONDEMAND config macro.

I'm fine with most cases (including here).

But I'm not sure if there is a case as `#if defined() || defined()`,
it seems it cannot be simply replaced with `#ifdef`.

Thanks,
Gao Xiang

> 
> Thanks,
> Hongbo

On Mon, Jan 19, 2026 at 09:44:59AM +0800, Gao Xiang wrote:
> But I'm not sure if there is a case as `#if defined() || defined()`,
> it seems it cannot be simply replaced with `#ifdef`.

They can't.  If you have multiple statements compined using operators
you need to use #if and defined().

Hi,

On 2026/1/19 9:44, Gao Xiang wrote:
> 
> 
> On 2026/1/19 09:34, Hongbo Li wrote:
>> Hi, Xiang
>>
>> On 2026/1/16 23:38, Christoph Hellwig wrote:
>>>> +#if defined(CONFIG_EROFS_FS_ONDEMAND)
>>>
>>> Normally this would just use #ifdef.
>>>
>> How about using #ifdef for all of them? I checked and there are only 
>> three places in total, and all of them are related to 
>> FS_PAGE_CACHE_SHARE or FS_ONDEMAND config macro.
> 
> I'm fine with most cases (including here).
> 
> But I'm not sure if there is a case as `#if defined() || defined()`,
> it seems it cannot be simply replaced with `#ifdef`.
> 
Yeah, we cannot replace it in this case. So I will keep it here because 
it will be changed into `#if defined() || defined()` in following steps. 
Instead, I will use this way in other place, such as:

```
#if defined(CONFIG_EROFS_FS_PAGE_CACHE_SHARE)
                 set_opt(&sbi->opt, INODE_SHARE);
#else
...
```

Thanks,
Hongbo


> Thanks,
> Gao Xiang
> 
>>
>> Thanks,
>> Hongbo
>