[PATCH v2 4/7] libfs: add alloc_anon_inode wrapper

[Emanuele Giuseppe Esposito]

libfs.c has many functions that are useful to implement dentry and inode
operations, but not many at the filesystem level. Start adding file
creation wrappers, the simplest returns an anonymous inode.

There is no functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit at redhat.com>
---
 drivers/gpu/drm/drm_drv.c       |  2 +-
 drivers/misc/cxl/api.c          |  2 +-
 drivers/scsi/cxlflash/ocxl_hw.c |  2 +-
 fs/libfs.c                      | 10 +++++++++-
 include/linux/fs.h              |  2 ++
 5 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index e29424d64874..1854f760ad39 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -539,7 +539,7 @@ static struct inode *drm_fs_inode_new(void)
 		return ERR_PTR(r);
 	}
 
-	inode = alloc_anon_inode(drm_fs.mount->mnt_sb);
+	inode = simple_alloc_anon_inode(&drm_fs);
 	if (IS_ERR(inode))
 		simple_release_fs(&drm_fs);
 
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index 67e4808bce49..57672abb6223 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -72,7 +72,7 @@ static struct file *cxl_getfile(const char *name,
 		goto err_module;
 	}
 
-	inode = alloc_anon_inode(cxl_fs.mount->mnt_sb);
+	inode = simple_alloc_anon_inode(&cxl_fs);
 	if (IS_ERR(inode)) {
 		file = ERR_CAST(inode);
 		goto err_fs;
diff --git a/drivers/scsi/cxlflash/ocxl_hw.c b/drivers/scsi/cxlflash/ocxl_hw.c
index 7fa98dd4fa28..0e9f2ae7eebf 100644
--- a/drivers/scsi/cxlflash/ocxl_hw.c
+++ b/drivers/scsi/cxlflash/ocxl_hw.c
@@ -85,7 +85,7 @@ static struct file *ocxlflash_getfile(struct device *dev, const char *name,
 		goto err2;
 	}
 
-	inode = alloc_anon_inode(ocxlflash_fs.mount->mnt_sb);
+	inode = simple_alloc_anon_inode(&ocxlflash_fs);
 	if (IS_ERR(inode)) {
 		rc = PTR_ERR(inode);
 		dev_err(dev, "%s: alloc_anon_inode failed rc=%d\n",
diff --git a/fs/libfs.c b/fs/libfs.c
index 3fa0cd27ab06..5c76e4c648dc 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -741,7 +741,15 @@ void simple_release_fs(struct simple_fs *fs)
 }
 EXPORT_SYMBOL(simple_release_fs);
 
-
+/**
+ * simple_alloc_anon_inode - wrapper for alloc_anon_inode
+ * @fs: a pointer to a struct simple_fs containing a valid vfs_mount pointer
+ **/
+struct inode *simple_alloc_anon_inode(struct simple_fs *fs)
+{
+	return alloc_anon_inode(fs->mount->mnt_sb);
+}
+EXPORT_SYMBOL(simple_alloc_anon_inode);
 
 /**
  * simple_read_from_buffer - copy data from the buffer to user space
diff --git a/include/linux/fs.h b/include/linux/fs.h
index de2577df30ae..5e93de72118b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3373,6 +3373,8 @@ struct simple_fs {
 extern int simple_pin_fs(struct simple_fs *, struct file_system_type *);
 extern void simple_release_fs(struct simple_fs *);
 
+extern struct inode *simple_alloc_anon_inode(struct simple_fs *fs);
+
 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
 			loff_t *ppos, const void *from, size_t available);
 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
-- 
2.25.2