// SPDX-License-Identifier: GPL-2.0-only #include "dev.h"#include "fuse_i.h" static int fuse_fill_creds(struct fuse_mount *fm, struct fuse_args *args, struct mnt_idmap *idmap){	struct fuse_conn *fc = fm->fc;	bool no_idmap = !fm->sb || (fm->sb->s_iflags & SB_I_NOIDMAP);	kuid_t fsuid = mapped_fsuid(idmap, fc->user_ns);	kgid_t fsgid = mapped_fsgid(idmap, fc->user_ns); 	args->pid = pid_nr_ns(task_pid(current), fc->pid_ns); 	if (args->force) {		if (args->nocreds)			return 0; 		if (no_idmap) {			args->uid = from_kuid_munged(fc->user_ns, current_fsuid());			args->gid = from_kgid_munged(fc->user_ns, current_fsgid());		} else {			args->uid = FUSE_INVALID_UIDGID;			args->gid = FUSE_INVALID_UIDGID;		}		return 0;	} 	WARN_ON(args->nocreds);	/*	 * Keep the old behavior when idmappings support was not	 * declared by a FUSE server.	 *	 * For those FUSE servers who support idmapped mounts, we send UID/GID	 * only along with "inode creation" fuse requests, otherwise idmap ==	 * &invalid_mnt_idmap and req->in.h.{u,g}id will be equal to	 * FUSE_INVALID_UIDGID.	 */	if (no_idmap) {		fsuid = current_fsuid();		fsgid = current_fsgid();	}	args->uid = from_kuid(fc->user_ns, fsuid);	args->gid = from_kgid(fc->user_ns, fsgid); 	if (no_idmap && unlikely(args->uid == ((uid_t)-1) || args->gid == ((gid_t)-1)))		return -EOVERFLOW; 	return 0;} static int fuse_req_prep(struct fuse_mount *fm, struct fuse_args *args, struct mnt_idmap *idmap){	if (!args->force && fm->fc->conn_error)		return -ECONNREFUSED; 	return fuse_fill_creds(fm, args, idmap);} ssize_t __fuse_simple_request(struct mnt_idmap *idmap, struct fuse_mount *fm,			      struct fuse_args *args){	struct fuse_conn *fc = fm->fc;	int err = fuse_req_prep(fm, args, idmap); 	if (err)		return err; 	return fuse_chan_send(fc->chan, args);} int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args, gfp_t gfp_flags){	struct fuse_conn *fc = fm->fc;	int err; 	WARN_ON(args->force && !args->nocreds); 	err = fuse_req_prep(fm, args, &invalid_mnt_idmap);	if (err)		return err; 	return fuse_chan_send_bg(fc->chan, args, gfp_flags);}EXPORT_SYMBOL_GPL(fuse_simple_background); int fuse_simple_notify_reply(struct fuse_mount *fm, struct fuse_args *args, u64 unique){	struct fuse_conn *fc = fm->fc;	int err; 	WARN_ON(args->force && !args->nocreds); 	err = fuse_req_prep(fm, args, &invalid_mnt_idmap);	if (err)		return err; 	return fuse_chan_send_notify_reply(fc->chan, args, unique);}