Commit 9751b338 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

vfs: move open right after ->tmpfile() 



Create a helper finish_open_simple() that opens the file with the original
dentry.  Handle the error case here as well to simplify callers.

Call this helper right after ->tmpfile() is called.

Next patch will change the tmpfile API and move this call into tmpfile
instances.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 3e9d4c59

fs/namei.c

+33 −50
Original line number Diff line number Diff line
@@ -3583,44 +3583,44 @@ static int do_open(struct nameidata *nd, 
 * On non-idmapped mounts or if permission checking is to be performed on the

 * raw inode simply passs init_user_ns.

 */

static struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns,

			   struct dentry *dentry, umode_t mode, int open_flag)

static int vfs_tmpfile(struct user_namespace *mnt_userns,

		       const struct path *parentpath,

		       struct file *file, umode_t mode)

{

	struct dentry *child = NULL;

	struct inode *dir = dentry->d_inode;

	struct dentry *child;

	struct inode *dir = d_inode(parentpath->dentry);

	struct inode *inode;

	int error;



	/* we want directory to be writable */

	error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);

	if (error)

		goto out_err;

	error = -EOPNOTSUPP;

		return error;

	if (!dir->i_op->tmpfile)

		goto out_err;

	error = -ENOMEM;

	child = d_alloc(dentry, &slash_name);

		return -EOPNOTSUPP;

	child = d_alloc(parentpath->dentry, &slash_name);

	if (unlikely(!child))

		goto out_err;

		return -ENOMEM;

	file->f_path.mnt = parentpath->mnt;

	file->f_path.dentry = child;

	mode = vfs_prepare_mode(mnt_userns, dir, mode, mode, mode);

	error = dir->i_op->tmpfile(mnt_userns, dir, child, mode);

	error = finish_open_simple(file, error);

	dput(child);

	if (error)

		goto out_err;

	error = -ENOENT;

	inode = child->d_inode;

	if (unlikely(!inode))

		goto out_err;

	if (!(open_flag & O_EXCL)) {

		return error;

	/* Don't check for other permissions, the inode was just created */

	error = may_open(mnt_userns, &file->f_path, 0, file->f_flags);

	if (error)

		return error;

	inode = file_inode(file);

	if (!(file->f_flags & O_EXCL)) {

		spin_lock(&inode->i_lock);

		inode->i_state |= I_LINKABLE;

		spin_unlock(&inode->i_lock);

	}

	ima_post_create_tmpfile(mnt_userns, inode);

	return child;



out_err:

	dput(child);

	return ERR_PTR(error);

	return 0;

}



/**
@@ -3641,25 +3641,15 @@ struct file *vfs_tmpfile_open(struct user_namespace *mnt_userns, 
{

	struct file *file;

	int error;

	struct path path = { .mnt = parentpath->mnt };



	path.dentry = vfs_tmpfile(mnt_userns, parentpath->dentry, mode, open_flag);

	if (IS_ERR(path.dentry))

		return ERR_CAST(path.dentry);



	error = may_open(mnt_userns, &path, 0, open_flag);

	file = alloc_empty_file_noaccount(open_flag, cred);

	if (!IS_ERR(file)) {

		error = vfs_tmpfile(mnt_userns, parentpath, file, mode);

		if (error) {

			fput(file);

			file = ERR_PTR(error);

	if (error)

		goto out_dput;



	/*

	 * This relies on the "noaccount" property of fake open, otherwise

	 * equivalent to dentry_open().

	 */

	file = open_with_fake_path(&path, open_flag, d_inode(path.dentry), cred);

out_dput:

	dput(path.dentry);



		}

	}

	return file;

}

EXPORT_SYMBOL(vfs_tmpfile_open);
@@ -3669,26 +3659,19 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, 
		struct file *file)

{

	struct user_namespace *mnt_userns;

	struct dentry *child;

	struct path path;

	int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path);



	if (unlikely(error))

		return error;

	error = mnt_want_write(path.mnt);

	if (unlikely(error))

		goto out;

	mnt_userns = mnt_user_ns(path.mnt);

	child = vfs_tmpfile(mnt_userns, path.dentry, op->mode, op->open_flag);

	error = PTR_ERR(child);

	if (IS_ERR(child))

	error = vfs_tmpfile(mnt_userns, &path, file, op->mode);

	if (error)

		goto out2;

	dput(path.dentry);

	path.dentry = child;

	audit_inode(nd->name, child, 0);

	/* Don't check for other permissions, the inode was just created */

	error = may_open(mnt_userns, &path, 0, op->open_flag);

	if (!error)

		error = vfs_open(&path, file);

	audit_inode(nd->name, file->f_path.dentry, 0);

out2:

	mnt_drop_write(path.mnt);

out:

include/linux/fs.h

+9 −0
Original line number Diff line number Diff line
@@ -2780,6 +2780,15 @@ extern int finish_open(struct file *file, struct dentry *dentry, 
			int (*open)(struct inode *, struct file *));

extern int finish_no_open(struct file *file, struct dentry *dentry);



/* Helper for the simple case when original dentry is used */

static inline int finish_open_simple(struct file *file, int error)

{

	if (error)

		return error;



	return finish_open(file, file->f_path.dentry, NULL);

}



/* fs/dcache.c */

extern void __init vfs_caches_init_early(void);

extern void __init vfs_caches_init(void);