[PATCH RFC v4 1/4] erofs: move `struct erofs_anon_fs_type` to super.c

[Hongzhen Luo <hongzhen@linux.alibaba.com>]

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

Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com>
---
v4: There are no changes compared to v3.
v3: https://lore.kernel.org/all/20240828111959.3677011-2-hongzhen@linux.alibaba.com/
v2: The patch set v2 does not move the `struct erofs_anon_fs_type` to super.c.
v1: https://lore.kernel.org/all/20240722065355.1396365-2-hongzhen@linux.alibaba.com/
---
 fs/erofs/fscache.c  | 13 -------------
 fs/erofs/internal.h |  2 ++
 fs/erofs/super.c    | 21 +++++++++++++++++++++
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index fda16eedafb5..826b2893acb2 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 45dc15ebd870..3d6bb1b36378 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -387,6 +387,8 @@ extern const struct file_operations erofs_dir_fops;
 
 extern const struct iomap_ops z_erofs_iomap_report_ops;
 
+extern struct file_system_type erofs_anon_fs_type;
+
 /* flags for erofs_fscache_register_cookie() */
 #define EROFS_REG_COOKIE_SHARE		0x0001
 #define EROFS_REG_COOKIE_NEED_NOEXIST	0x0002
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 6cb5c8916174..afca576144ca 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -10,6 +10,7 @@
 #include <linux/fs_context.h>
 #include <linux/fs_parser.h>
 #include <linux/exportfs.h>
+#include <linux/pseudo_fs.h>
 #include "xattr.h"
 
 #define CREATE_TRACE_POINTS
@@ -834,6 +835,26 @@ static struct file_system_type erofs_fs_type = {
 };
 MODULE_ALIAS_FS("erofs");
 
+static const struct super_operations erofs_anon_sops = {
+	.statfs	= simple_statfs,
+};
+
+static int erofs_anon_init_fs_context(struct fs_context *fc)
+{
+	struct pseudo_fs_context *ctx = init_pseudo(fc, EROFS_SUPER_MAGIC);
+
+	if (ctx)
+		ctx->ops = &erofs_anon_sops;
+	return ctx ? 0 : -ENOMEM;
+}
+
+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,
+};
+
 static int __init erofs_module_init(void)
 {
 	int err;
-- 
2.43.5