Merge tag 'vboxsf-v5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hansg/linux

Pull vboxsf fixes from Hans de Goede:
 "This adds support for the atomic_open directory-inode op to vboxsf.

  Note this is not just an enhancement this also fixes an actual issue
  which users are hitting, see the commit message of the "boxsf: Add
  support for the atomic_open directory-inode" patch"

* tag 'vboxsf-v5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hansg/linux:
  vboxsf: Add support for the atomic_open directory-inode op
  vboxsf: Add vboxsf_[create|release]_sf_handle() helpers
  vboxsf: Make vboxsf_dir_create() return the handle for the created file
  vboxsf: Honor excl flag to the dir-inode create op

3 files changed, 116 insertions, 38 deletions

diff --git a/fs/vboxsf/dir.c b/fs/vboxsf/dir.c
index eac6788fc6cf..c4769a9396c5 100644
--- a/fs/vboxsf/dir.c
+++ b/fs/vboxsf/dir.c
@@ -253,7 +253,7 @@ static int vboxsf_dir_instantiate(struct inode *parent, struct dentry *dentry,
 }
 
 static int vboxsf_dir_create(struct inode *parent, struct dentry *dentry,
-			     umode_t mode, int is_dir)
+			     umode_t mode, bool is_dir, bool excl, u64 *handle_ret)
 {
 	struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
 	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
@@ -261,10 +261,12 @@ static int vboxsf_dir_create(struct inode *parent, struct dentry *dentry,
 	int err;
 
 	params.handle = SHFL_HANDLE_NIL;
-	params.create_flags = SHFL_CF_ACT_CREATE_IF_NEW |
-			      SHFL_CF_ACT_FAIL_IF_EXISTS |
-			      SHFL_CF_ACCESS_READWRITE |
-			      (is_dir ? SHFL_CF_DIRECTORY : 0);
+	params.create_flags = SHFL_CF_ACT_CREATE_IF_NEW | SHFL_CF_ACCESS_READWRITE;
+	if (is_dir)
+		params.create_flags |= SHFL_CF_DIRECTORY;
+	if (excl)
+		params.create_flags |= SHFL_CF_ACT_FAIL_IF_EXISTS;
+
 	params.info.attr.mode = (mode & 0777) |
 				(is_dir ? SHFL_TYPE_DIRECTORY : SHFL_TYPE_FILE);
 	params.info.attr.additional = SHFLFSOBJATTRADD_NOTHING;
@@ -276,30 +278,81 @@ static int vboxsf_dir_create(struct inode *parent, struct dentry *dentry,
 	if (params.result != SHFL_FILE_CREATED)
 		return -EPERM;
 
-	vboxsf_close(sbi->root, params.handle);
-
 	err = vboxsf_dir_instantiate(parent, dentry, &params.info);
 	if (err)
-		return err;
+		goto out;
 
 	/* parent directory access/change time changed */
 	sf_parent_i->force_restat = 1;
 
-	return 0;
+out:
+	if (err == 0 && handle_ret)
+		*handle_ret = params.handle;
+	else
+		vboxsf_close(sbi->root, params.handle);
+
+	return err;
 }
 
 static int vboxsf_dir_mkfile(struct user_namespace *mnt_userns,
 			     struct inode *parent, struct dentry *dentry,
 			     umode_t mode, bool excl)
 {
-	return vboxsf_dir_create(parent, dentry, mode, 0);
+	return vboxsf_dir_create(parent, dentry, mode, false, excl, NULL);
 }
 
 static int vboxsf_dir_mkdir(struct user_namespace *mnt_userns,
 			    struct inode *parent, struct dentry *dentry,
 			    umode_t mode)
 {
-	return vboxsf_dir_create(parent, dentry, mode, 1);
+	return vboxsf_dir_create(parent, dentry, mode, true, true, NULL);
+}
+
+static int vboxsf_dir_atomic_open(struct inode *parent, struct dentry *dentry,
+				  struct file *file, unsigned int flags, umode_t mode)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
+	struct vboxsf_handle *sf_handle;
+	struct dentry *res = NULL;
+	u64 handle;
+	int err;
+
+	if (d_in_lookup(dentry)) {
+		res = vboxsf_dir_lookup(parent, dentry, 0);
+		if (IS_ERR(res))
+			return PTR_ERR(res);
+
+		if (res)
+			dentry = res;
+	}
+
+	/* Only creates */
+	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
+		return finish_no_open(file, res);
+
+	err = vboxsf_dir_create(parent, dentry, mode, false, flags & O_EXCL, &handle);
+	if (err)
+		goto out;
+
+	sf_handle = vboxsf_create_sf_handle(d_inode(dentry), handle, SHFL_CF_ACCESS_READWRITE);
+	if (IS_ERR(sf_handle)) {
+		vboxsf_close(sbi->root, handle);
+		err = PTR_ERR(sf_handle);
+		goto out;
+	}
+
+	err = finish_open(file, dentry, generic_file_open);
+	if (err) {
+		/* This also closes the handle passed to vboxsf_create_sf_handle() */
+		vboxsf_release_sf_handle(d_inode(dentry), sf_handle);
+		goto out;
+	}
+
+	file->private_data = sf_handle;
+	file->f_mode |= FMODE_CREATED;
+out:
+	dput(res);
+	return err;
 }
 
 static int vboxsf_dir_unlink(struct inode *parent, struct dentry *dentry)
@@ -422,6 +475,7 @@ const struct inode_operations vboxsf_dir_iops = {
 	.lookup  = vboxsf_dir_lookup,
 	.create  = vboxsf_dir_mkfile,
 	.mkdir   = vboxsf_dir_mkdir,
+	.atomic_open = vboxsf_dir_atomic_open,
 	.rmdir   = vboxsf_dir_unlink,
 	.unlink  = vboxsf_dir_unlink,
 	.rename  = vboxsf_dir_rename,
diff --git a/fs/vboxsf/file.c b/fs/vboxsf/file.c
index c4ab5996d97a..864c2fad23be 100644
--- 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 *inode, struct file *file)
 	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 kref *refcount)
 	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;
 }
 
diff --git a/fs/vboxsf/vfsmod.h b/fs/vboxsf/vfsmod.h
index 6a7a9cedebc6..9047befa66c5 100644
--- 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 vboxsf_reg_fops;
 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);
 int vboxsf_init_inode(struct vboxsf_sbi *sbi, struct inode *inode,