[PATCH 5.10 91/96] vboxsf: Add vboxsf_[create|release]_sf_handle() helpers

Greg Kroah-Hartman
2021-08-16T13:14:41Z

From: Hans de Goede <hdegoede@redhat.com>

commit 02f840f90764f22f5c898901849bdbf0cee752ba upstream.

Factor out the code to create / release a struct vboxsf_handle into
2 new helper functions.

This is a preparation patch for adding atomic_open support.

Fixes: 0fd169576648 ("fs: Add VirtualBox guest shared folder (vboxsf) support")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/vboxsf/file.c | 71 ++++++++++++++++++++++++++++++++---------------------
fs/vboxsf/vfsmod.h | 7 +++++
2 files changed, 51 insertions(+), 27 deletions(-)

--- a/fs/vboxsf/file.c
+++ b/fs/vboxsf/file.c
@@ -20,17 +20,39 @@ struct vboxsf_handle {
struct list_head head;
};

-static int vboxsf_file_open(struct inode *inode, struct file *file)
+struct vboxsf_handle *vboxsf_create_sf_handle(struct inode *inode,
+ u64 handle, u32 access_flags)
{
struct vboxsf_inode *sf_i = VBOXSF_I(inode);
- struct shfl_createparms params = {};
struct vboxsf_handle *sf_handle;
- u32 access_flags = 0;
- int err;

sf_handle = kmalloc(sizeof(*sf_handle), GFP_KERNEL);
if (!sf_handle)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
+
+ /* the host may have given us different attr then requested */
+ sf_i->force_restat = 1;
+
+ /* init our handle struct and add it to the inode's handles list */
+ sf_handle->handle = handle;
+ sf_handle->root = VBOXSF_SBI(inode->i_sb)->root;
+ sf_handle->access_flags = access_flags;
+ kref_init(&sf_handle->refcount);
+
+ mutex_lock(&sf_i->handle_list_mutex);
+ list_add(&sf_handle->head, &sf_i->handle_list);
+ mutex_unlock(&sf_i->handle_list_mutex);
+
+ return sf_handle;
+}
+
+static int vboxsf_file_open(struct inode *inode, struct file *file)
+{
+ struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb);
+ struct shfl_createparms params = {};
+ struct vboxsf_handle *sf_handle;
+ u32 access_flags = 0;
+ int err;

/*
* We check the value of params.handle afterwards to find out if
@@ -83,23 +105,14 @@ static int vboxsf_file_open(struct inode
err = vboxsf_create_at_dentry(file_dentry(file), &params);
if (err == 0 && params.handle == SHFL_HANDLE_NIL)
err = (params.result == SHFL_FILE_EXISTS) ? -EEXIST : -ENOENT;
- if (err) {
- kfree(sf_handle);
+ if (err)
return err;
- }

- /* the host may have given us different attr then requested */
- sf_i->force_restat = 1;
-
- /* init our handle struct and add it to the inode's handles list */
- sf_handle->handle = params.handle;
- sf_handle->root = VBOXSF_SBI(inode->i_sb)->root;
- sf_handle->access_flags = access_flags;
- kref_init(&sf_handle->refcount);
-
- mutex_lock(&sf_i->handle_list_mutex);
- list_add(&sf_handle->head, &sf_i->handle_list);
- mutex_unlock(&sf_i->handle_list_mutex);
+ sf_handle = vboxsf_create_sf_handle(inode, params.handle, access_flags);
+ if (IS_ERR(sf_handle)) {
+ vboxsf_close(sbi->root, params.handle);
+ return PTR_ERR(sf_handle);
+ }

file->private_data = sf_handle;
return 0;
@@ -114,22 +127,26 @@ static void vboxsf_handle_release(struct
kfree(sf_handle);
}

-static int vboxsf_file_release(struct inode *inode, struct file *file)
+void vboxsf_release_sf_handle(struct inode *inode, struct vboxsf_handle *sf_handle)
{
struct vboxsf_inode *sf_i = VBOXSF_I(inode);
- struct vboxsf_handle *sf_handle = file->private_data;

+ mutex_lock(&sf_i->handle_list_mutex);
+ list_del(&sf_handle->head);
+ mutex_unlock(&sf_i->handle_list_mutex);
+
+ kref_put(&sf_handle->refcount, vboxsf_handle_release);
+}
+
+static int vboxsf_file_release(struct inode *inode, struct file *file)
+{
/*
* When a file is closed on our (the guest) side, we want any subsequent
* accesses done on the host side to see all changes done from our side.
*/
filemap_write_and_wait(inode->i_mapping);

- mutex_lock(&sf_i->handle_list_mutex);
- list_del(&sf_handle->head);
- mutex_unlock(&sf_i->handle_list_mutex);
-
- kref_put(&sf_handle->refcount, vboxsf_handle_release);
+ vboxsf_release_sf_handle(inode, file->private_data);
return 0;
}

--- a/fs/vboxsf/vfsmod.h
+++ b/fs/vboxsf/vfsmod.h
@@ -18,6 +18,8 @@
#define VBOXSF_SBI(sb) ((struct vboxsf_sbi *)(sb)->s_fs_info)
#define VBOXSF_I(i) container_of(i, struct vboxsf_inode, vfs_inode)

+struct vboxsf_handle;
+
struct vboxsf_options {
unsigned long ttl;
kuid_t uid;
@@ -80,6 +82,11 @@ extern const struct file_operations vbox
extern const struct address_space_operations vboxsf_reg_aops;
extern const struct dentry_operations vboxsf_dentry_ops;

+/* from file.c */
+struct vboxsf_handle *vboxsf_create_sf_handle(struct inode *inode,
+ u64 handle, u32 access_flags);
+void vboxsf_release_sf_handle(struct inode *inode, struct vboxsf_handle *sf_handle);
+
/* from utils.c */
struct inode *vboxsf_new_inode(struct super_block *sb);
void vboxsf_init_inode(struct vboxsf_sbi *sbi, struct inode *inode,