fs/bcachefs/fs-ioctl.c - linux/torvalds/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 #ifndef NO_BCACHEFS_FS

 #include "bcachefs.h"
 #include "chardev.h"
 #include "dirent.h"
 #include "fs.h"
 #include "fs-ioctl.h"
 #include "namei.h"
 #include "quota.h"

 #include <linux/compat.h>
 #include <linux/fsnotify.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/security.h>
 #include <linux/writeback.h>

 #define FS_IOC_GOINGDOWN	     _IOR('X', 125, __u32)
 #define FSOP_GOING_FLAGS_DEFAULT	0x0	/* going down */
 #define FSOP_GOING_FLAGS_LOGFLUSH	0x1	/* flush log but not data */
 #define FSOP_GOING_FLAGS_NOLOGFLUSH	0x2	/* don't flush log nor data */

 static int bch2_reinherit_attrs_fn(struct btree_trans *trans,
 				   struct bch_inode_info *inode,
 				   struct bch_inode_unpacked *bi,
 				   void *p)
 {
 	struct bch_inode_info *dir = p;

 	return !bch2_reinherit_attrs(bi, &dir->ei_inode);
 }

 static int bch2_ioc_reinherit_attrs(struct bch_fs *c,
 				    struct file *file,
 				    struct bch_inode_info *src,
 				    const char __user *name)
 {
 	struct bch_hash_info hash = bch2_hash_info_init(c, &src->ei_inode);
 	struct bch_inode_info *dst;
 	struct inode *vinode = NULL;
 	char *kname = NULL;
 	struct qstr qstr;
 	int ret = 0;
 	subvol_inum inum;

 	kname = kmalloc(BCH_NAME_MAX, GFP_KERNEL);
 	if (!kname)
 		return -ENOMEM;

 	ret = strncpy_from_user(kname, name, BCH_NAME_MAX);
 	if (unlikely(ret < 0))
 		goto err1;

 	qstr.len	= ret;
 	qstr.name	= kname;

 	ret = bch2_dirent_lookup(c, inode_inum(src), &hash, &qstr, &inum);
 	if (ret)
 		goto err1;

 	vinode = bch2_vfs_inode_get(c, inum);
 	ret = PTR_ERR_OR_ZERO(vinode);
 	if (ret)
 		goto err1;

 	dst = to_bch_ei(vinode);

 	ret = mnt_want_write_file(file);
 	if (ret)
 		goto err2;

 	bch2_lock_inodes(INODE_UPDATE_LOCK, src, dst);

 	if (inode_attr_changing(src, dst, Inode_opt_project)) {
 		ret = bch2_fs_quota_transfer(c, dst,
 					     src->ei_qid,
 					     1 << QTYP_PRJ,
 					     KEY_TYPE_QUOTA_PREALLOC);
 		if (ret)
 			goto err3;
 	}

 	ret = bch2_write_inode(c, dst, bch2_reinherit_attrs_fn, src, 0);
 err3:
 	bch2_unlock_inodes(INODE_UPDATE_LOCK, src, dst);

 	/* return true if we did work */
 	if (ret >= 0)
 		ret = !ret;

 	mnt_drop_write_file(file);
 err2:
 	iput(vinode);
 err1:
 	kfree(kname);

 	return ret;
 }

 static int bch2_ioc_getversion(struct bch_inode_info *inode, u32 __user *arg)
 {
 	return put_user(inode->v.i_generation, arg);
 }

 static int bch2_ioc_getlabel(struct bch_fs *c, char __user *user_label)
 {
 	int ret;
 	size_t len;
 	char label[BCH_SB_LABEL_SIZE];

 	BUILD_BUG_ON(BCH_SB_LABEL_SIZE >= FSLABEL_MAX);

 	mutex_lock(&c->sb_lock);
 	memcpy(label, c->disk_sb.sb->label, BCH_SB_LABEL_SIZE);
 	mutex_unlock(&c->sb_lock);

 	len = strnlen(label, BCH_SB_LABEL_SIZE);
 	if (len == BCH_SB_LABEL_SIZE) {
 		bch_warn(c,
 			"label is too long, return the first %zu bytes",
 			--len);
 	}

 	ret = copy_to_user(user_label, label, len);

 	return ret ? -EFAULT : 0;
 }

 static int bch2_ioc_setlabel(struct bch_fs *c,
 			     struct file *file,
 			     struct bch_inode_info *inode,
 			     const char __user *user_label)
 {
 	int ret;
 	char label[BCH_SB_LABEL_SIZE];

 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;

 	if (copy_from_user(label, user_label, sizeof(label)))
 		return -EFAULT;

 	if (strnlen(label, BCH_SB_LABEL_SIZE) == BCH_SB_LABEL_SIZE) {
 		bch_err(c,
 			"unable to set label with more than %d bytes",
 			BCH_SB_LABEL_SIZE - 1);
 		return -EINVAL;
 	}

 	ret = mnt_want_write_file(file);
 	if (ret)
 		return ret;

 	mutex_lock(&c->sb_lock);
 	strscpy(c->disk_sb.sb->label, label, BCH_SB_LABEL_SIZE);
 	ret = bch2_write_super(c);
 	mutex_unlock(&c->sb_lock);

 	mnt_drop_write_file(file);
 	return ret;
 }

 static int bch2_ioc_goingdown(struct bch_fs *c, u32 __user *arg)
 {
 	u32 flags;
 	int ret = 0;

 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;

 	if (get_user(flags, arg))
 		return -EFAULT;

 	bch_notice(c, "shutdown by ioctl type %u", flags);

 	switch (flags) {
 	case FSOP_GOING_FLAGS_DEFAULT:
 		ret = bdev_freeze(c->vfs_sb->s_bdev);
 		if (ret)
 			break;
 		bch2_journal_flush(&c->journal);
 		bch2_fs_emergency_read_only(c);
 		bdev_thaw(c->vfs_sb->s_bdev);
 		break;
 	case FSOP_GOING_FLAGS_LOGFLUSH:
 		bch2_journal_flush(&c->journal);
 		fallthrough;
 	case FSOP_GOING_FLAGS_NOLOGFLUSH:
 		bch2_fs_emergency_read_only(c);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	return ret;
 }

 static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
 					struct bch_ioctl_subvolume arg)
 {
 	struct inode *dir;
 	struct bch_inode_info *inode;
 	struct user_namespace *s_user_ns;
 	struct dentry *dst_dentry;
 	struct path src_path, dst_path;
 	int how = LOOKUP_FOLLOW;
 	int error;
 	subvol_inum snapshot_src = { 0 };
 	unsigned lookup_flags = 0;
 	unsigned create_flags = BCH_CREATE_SUBVOL;

 	if (arg.flags & ~(BCH_SUBVOL_SNAPSHOT_CREATE|
 			  BCH_SUBVOL_SNAPSHOT_RO))
 		return -EINVAL;

 	if (!(arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
 	    (arg.src_ptr ||
 	     (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)))
 		return -EINVAL;

 	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
 		create_flags |= BCH_CREATE_SNAPSHOT;

 	if (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)
 		create_flags |= BCH_CREATE_SNAPSHOT_RO;

 	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) {
 		/* sync_inodes_sb enforce s_umount is locked */
 		down_read(&c->vfs_sb->s_umount);
 		sync_inodes_sb(c->vfs_sb);
 		up_read(&c->vfs_sb->s_umount);
 	}

 	if (arg.src_ptr) {
 		error = user_path_at(arg.dirfd,
 				(const char __user *)(unsigned long)arg.src_ptr,
 				how, &src_path);
 		if (error)
 			goto err1;

 		if (src_path.dentry->d_sb->s_fs_info != c) {
 			path_put(&src_path);
 			error = -EXDEV;
 			goto err1;
 		}

 		snapshot_src = inode_inum(to_bch_ei(src_path.dentry->d_inode));
 	}

 	dst_dentry = user_path_create(arg.dirfd,
 			(const char __user *)(unsigned long)arg.dst_ptr,
 			&dst_path, lookup_flags);
 	error = PTR_ERR_OR_ZERO(dst_dentry);
 	if (error)
 		goto err2;

 	if (dst_dentry->d_sb->s_fs_info != c) {
 		error = -EXDEV;
 		goto err3;
 	}

 	if (dst_dentry->d_inode) {
 		error = -BCH_ERR_EEXIST_subvolume_create;
 		goto err3;
 	}

 	dir = dst_path.dentry->d_inode;
 	if (IS_DEADDIR(dir)) {
 		error = -BCH_ERR_ENOENT_directory_dead;
 		goto err3;
 	}

 	s_user_ns = dir->i_sb->s_user_ns;
 	if (!kuid_has_mapping(s_user_ns, current_fsuid()) ||
 	    !kgid_has_mapping(s_user_ns, current_fsgid())) {
 		error = -EOVERFLOW;
 		goto err3;
 	}

 	error = inode_permission(file_mnt_idmap(filp),
 				 dir, MAY_WRITE | MAY_EXEC);
 	if (error)
 		goto err3;

 	if (!IS_POSIXACL(dir))
 		arg.mode &= ~current_umask();

 	error = security_path_mkdir(&dst_path, dst_dentry, arg.mode);
 	if (error)
 		goto err3;

 	if ((arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
 	    !arg.src_ptr)
 		snapshot_src.subvol = inode_inum(to_bch_ei(dir)).subvol;

 	down_write(&c->snapshot_create_lock);
 	inode = __bch2_create(file_mnt_idmap(filp), to_bch_ei(dir),
 			      dst_dentry, arg.mode|S_IFDIR,
 			      0, snapshot_src, create_flags);
 	up_write(&c->snapshot_create_lock);

 	error = PTR_ERR_OR_ZERO(inode);
 	if (error)
 		goto err3;

 	d_instantiate(dst_dentry, &inode->v);
 	fsnotify_mkdir(dir, dst_dentry);
 err3:
 	done_path_create(&dst_path, dst_dentry);
 err2:
 	if (arg.src_ptr)
 		path_put(&src_path);
 err1:
 	return error;
 }

 static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
 				struct bch_ioctl_subvolume arg)
 {
 	const char __user *name = (void __user *)(unsigned long)arg.dst_ptr;
 	struct path path;
 	struct inode *dir;
 	struct dentry *victim;
 	int ret = 0;

 	if (arg.flags)
 		return -EINVAL;

 	victim = user_path_locked_at(arg.dirfd, name, &path);
 	if (IS_ERR(victim))
 		return PTR_ERR(victim);

 	dir = d_inode(path.dentry);
 	if (victim->d_sb->s_fs_info != c) {
 		ret = -EXDEV;
 		goto err;
 	}

 	ret =   inode_permission(file_mnt_idmap(filp), d_inode(victim), MAY_WRITE) ?:
 		__bch2_unlink(dir, victim, true);
 	if (!ret) {
 		fsnotify_rmdir(dir, victim);
 		d_invalidate(victim);
 	}
 err:
 	inode_unlock(dir);
 	dput(victim);
 	path_put(&path);
 	return ret;
 }

 long bch2_fs_file_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
 	struct bch_inode_info *inode = file_bch_inode(file);
 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
 	long ret;

 	switch (cmd) {
 	case BCHFS_IOC_REINHERIT_ATTRS:
 		ret = bch2_ioc_reinherit_attrs(c, file, inode,
 					       (void __user *) arg);
 		break;

 	case FS_IOC_GETVERSION:
 		ret = bch2_ioc_getversion(inode, (u32 __user *) arg);
 		break;

 	case FS_IOC_SETVERSION:
 		ret = -ENOTTY;
 		break;

 	case FS_IOC_GETFSLABEL:
 		ret = bch2_ioc_getlabel(c, (void __user *) arg);
 		break;

 	case FS_IOC_SETFSLABEL:
 		ret = bch2_ioc_setlabel(c, file, inode, (const void __user *) arg);
 		break;

 	case FS_IOC_GOINGDOWN:
 		ret = bch2_ioc_goingdown(c, (u32 __user *) arg);
 		break;

 	case BCH_IOCTL_SUBVOLUME_CREATE: {
 		struct bch_ioctl_subvolume i;

 		ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
 			? -EFAULT
 			: bch2_ioctl_subvolume_create(c, file, i);
 		break;
 	}

 	case BCH_IOCTL_SUBVOLUME_DESTROY: {
 		struct bch_ioctl_subvolume i;

 		ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
 			? -EFAULT
 			: bch2_ioctl_subvolume_destroy(c, file, i);
 		break;
 	}

 	default:
 		ret = bch2_fs_ioctl(c, cmd, (void __user *) arg);
 		break;
 	}

 	return bch2_err_class(ret);
 }

 #ifdef CONFIG_COMPAT
 long bch2_compat_fs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
 	/* These are just misnamed, they actually get/put from/to user an int */
 	switch (cmd) {
 	case FS_IOC32_GETFLAGS:
 		cmd = FS_IOC_GETFLAGS;
 		break;
 	case FS_IOC32_SETFLAGS:
 		cmd = FS_IOC_SETFLAGS;
 		break;
 	case FS_IOC32_GETVERSION:
 		cmd = FS_IOC_GETVERSION;
 		break;
 	case FS_IOC_GETFSLABEL:
 	case FS_IOC_SETFSLABEL:
 		break;
 	default:
 		return -ENOIOCTLCMD;
 	}
 	return bch2_fs_file_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 }
 #endif

 #endif /* NO_BCACHEFS_FS */
	// SPDX-License-Identifier: GPL-2.0
	#ifndef NO_BCACHEFS_FS

	#include "bcachefs.h"
	#include "chardev.h"
	#include "dirent.h"
	#include "fs.h"
	#include "fs-ioctl.h"
	#include "namei.h"
	#include "quota.h"

	#include <linux/compat.h>
	#include <linux/fsnotify.h>
	#include <linux/mount.h>
	#include <linux/namei.h>
	#include <linux/security.h>
	#include <linux/writeback.h>

	#define FS_IOC_GOINGDOWN _IOR('X', 125, __u32)
	#define FSOP_GOING_FLAGS_DEFAULT 0x0 /* going down */
	#define FSOP_GOING_FLAGS_LOGFLUSH 0x1 /* flush log but not data */
	#define FSOP_GOING_FLAGS_NOLOGFLUSH 0x2 /* don't flush log nor data */

	static int bch2_reinherit_attrs_fn(struct btree_trans *trans,
	struct bch_inode_info *inode,
	struct bch_inode_unpacked *bi,
	void *p)
	{
	struct bch_inode_info *dir = p;

	return !bch2_reinherit_attrs(bi, &dir->ei_inode);
	}

	static int bch2_ioc_reinherit_attrs(struct bch_fs *c,
	struct file *file,
	struct bch_inode_info *src,
	const char __user *name)
	{
	struct bch_hash_info hash = bch2_hash_info_init(c, &src->ei_inode);
	struct bch_inode_info *dst;
	struct inode *vinode = NULL;
	char *kname = NULL;
	struct qstr qstr;
	int ret = 0;
	subvol_inum inum;

	kname = kmalloc(BCH_NAME_MAX, GFP_KERNEL);
	if (!kname)
	return -ENOMEM;

	ret = strncpy_from_user(kname, name, BCH_NAME_MAX);
	if (unlikely(ret < 0))
	goto err1;

	qstr.len = ret;
	qstr.name = kname;

	ret = bch2_dirent_lookup(c, inode_inum(src), &hash, &qstr, &inum);
	if (ret)
	goto err1;

	vinode = bch2_vfs_inode_get(c, inum);
	ret = PTR_ERR_OR_ZERO(vinode);
	if (ret)
	goto err1;

	dst = to_bch_ei(vinode);

	ret = mnt_want_write_file(file);
	if (ret)
	goto err2;

	bch2_lock_inodes(INODE_UPDATE_LOCK, src, dst);

	if (inode_attr_changing(src, dst, Inode_opt_project)) {
	ret = bch2_fs_quota_transfer(c, dst,
	src->ei_qid,
	1 << QTYP_PRJ,
	KEY_TYPE_QUOTA_PREALLOC);
	if (ret)
	goto err3;
	}

	ret = bch2_write_inode(c, dst, bch2_reinherit_attrs_fn, src, 0);
	err3:
	bch2_unlock_inodes(INODE_UPDATE_LOCK, src, dst);

	/* return true if we did work */
	if (ret >= 0)
	ret = !ret;

	mnt_drop_write_file(file);
	err2:
	iput(vinode);
	err1:
	kfree(kname);

	return ret;
	}

	static int bch2_ioc_getversion(struct bch_inode_info inode, u32 __user arg)
	{
	return put_user(inode->v.i_generation, arg);
	}

	static int bch2_ioc_getlabel(struct bch_fs c, char __user user_label)
	{
	int ret;
	size_t len;
	char label[BCH_SB_LABEL_SIZE];

	BUILD_BUG_ON(BCH_SB_LABEL_SIZE >= FSLABEL_MAX);

	mutex_lock(&c->sb_lock);
	memcpy(label, c->disk_sb.sb->label, BCH_SB_LABEL_SIZE);
	mutex_unlock(&c->sb_lock);

	len = strnlen(label, BCH_SB_LABEL_SIZE);
	if (len == BCH_SB_LABEL_SIZE) {
	bch_warn(c,
	"label is too long, return the first %zu bytes",
	--len);
	}

	ret = copy_to_user(user_label, label, len);

	return ret ? -EFAULT : 0;
	}

	static int bch2_ioc_setlabel(struct bch_fs *c,
	struct file *file,
	struct bch_inode_info *inode,
	const char __user *user_label)
	{
	int ret;
	char label[BCH_SB_LABEL_SIZE];

	if (!capable(CAP_SYS_ADMIN))
	return -EPERM;

	if (copy_from_user(label, user_label, sizeof(label)))
	return -EFAULT;

	if (strnlen(label, BCH_SB_LABEL_SIZE) == BCH_SB_LABEL_SIZE) {
	bch_err(c,
	"unable to set label with more than %d bytes",
	BCH_SB_LABEL_SIZE - 1);
	return -EINVAL;
	}

	ret = mnt_want_write_file(file);
	if (ret)
	return ret;

	mutex_lock(&c->sb_lock);
	strscpy(c->disk_sb.sb->label, label, BCH_SB_LABEL_SIZE);
	ret = bch2_write_super(c);
	mutex_unlock(&c->sb_lock);

	mnt_drop_write_file(file);
	return ret;
	}

	static int bch2_ioc_goingdown(struct bch_fs c, u32 __user arg)
	{
	u32 flags;
	int ret = 0;

	if (!capable(CAP_SYS_ADMIN))
	return -EPERM;

	if (get_user(flags, arg))
	return -EFAULT;

	bch_notice(c, "shutdown by ioctl type %u", flags);

	switch (flags) {
	case FSOP_GOING_FLAGS_DEFAULT:
	ret = bdev_freeze(c->vfs_sb->s_bdev);
	if (ret)
	break;
	bch2_journal_flush(&c->journal);
	bch2_fs_emergency_read_only(c);
	bdev_thaw(c->vfs_sb->s_bdev);
	break;
	case FSOP_GOING_FLAGS_LOGFLUSH:
	bch2_journal_flush(&c->journal);
	fallthrough;
	case FSOP_GOING_FLAGS_NOLOGFLUSH:
	bch2_fs_emergency_read_only(c);
	break;
	default:
	ret = -EINVAL;
	break;
	}

	return ret;
	}

	static long bch2_ioctl_subvolume_create(struct bch_fs c, struct file filp,
	struct bch_ioctl_subvolume arg)
	{
	struct inode *dir;
	struct bch_inode_info *inode;
	struct user_namespace *s_user_ns;
	struct dentry *dst_dentry;
	struct path src_path, dst_path;
	int how = LOOKUP_FOLLOW;
	int error;
	subvol_inum snapshot_src = { 0 };
	unsigned lookup_flags = 0;
	unsigned create_flags = BCH_CREATE_SUBVOL;

	if (arg.flags & ~(BCH_SUBVOL_SNAPSHOT_CREATE\|
	BCH_SUBVOL_SNAPSHOT_RO))
	return -EINVAL;

	if (!(arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
	(arg.src_ptr \|\|
	(arg.flags & BCH_SUBVOL_SNAPSHOT_RO)))
	return -EINVAL;

	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
	create_flags \|= BCH_CREATE_SNAPSHOT;

	if (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)
	create_flags \|= BCH_CREATE_SNAPSHOT_RO;

	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) {
	/* sync_inodes_sb enforce s_umount is locked */
	down_read(&c->vfs_sb->s_umount);
	sync_inodes_sb(c->vfs_sb);
	up_read(&c->vfs_sb->s_umount);
	}

	if (arg.src_ptr) {
	error = user_path_at(arg.dirfd,
	(const char __user *)(unsigned long)arg.src_ptr,
	how, &src_path);
	if (error)
	goto err1;

	if (src_path.dentry->d_sb->s_fs_info != c) {
	path_put(&src_path);
	error = -EXDEV;
	goto err1;
	}

	snapshot_src = inode_inum(to_bch_ei(src_path.dentry->d_inode));
	}

	dst_dentry = user_path_create(arg.dirfd,
	(const char __user *)(unsigned long)arg.dst_ptr,
	&dst_path, lookup_flags);
	error = PTR_ERR_OR_ZERO(dst_dentry);
	if (error)
	goto err2;

	if (dst_dentry->d_sb->s_fs_info != c) {
	error = -EXDEV;
	goto err3;
	}

	if (dst_dentry->d_inode) {
	error = -BCH_ERR_EEXIST_subvolume_create;
	goto err3;
	}

	dir = dst_path.dentry->d_inode;
	if (IS_DEADDIR(dir)) {
	error = -BCH_ERR_ENOENT_directory_dead;
	goto err3;
	}

	s_user_ns = dir->i_sb->s_user_ns;
	if (!kuid_has_mapping(s_user_ns, current_fsuid()) \|\|
	!kgid_has_mapping(s_user_ns, current_fsgid())) {
	error = -EOVERFLOW;
	goto err3;
	}

	error = inode_permission(file_mnt_idmap(filp),
	dir, MAY_WRITE \| MAY_EXEC);
	if (error)
	goto err3;

	if (!IS_POSIXACL(dir))
	arg.mode &= ~current_umask();

	error = security_path_mkdir(&dst_path, dst_dentry, arg.mode);
	if (error)
	goto err3;

	if ((arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
	!arg.src_ptr)
	snapshot_src.subvol = inode_inum(to_bch_ei(dir)).subvol;

	down_write(&c->snapshot_create_lock);
	inode = __bch2_create(file_mnt_idmap(filp), to_bch_ei(dir),
	dst_dentry, arg.mode\|S_IFDIR,
	0, snapshot_src, create_flags);
	up_write(&c->snapshot_create_lock);

	error = PTR_ERR_OR_ZERO(inode);
	if (error)
	goto err3;

	d_instantiate(dst_dentry, &inode->v);
	fsnotify_mkdir(dir, dst_dentry);
	err3:
	done_path_create(&dst_path, dst_dentry);
	err2:
	if (arg.src_ptr)
	path_put(&src_path);
	err1:
	return error;
	}

	static long bch2_ioctl_subvolume_destroy(struct bch_fs c, struct file filp,
	struct bch_ioctl_subvolume arg)
	{
	const char __user name = (void __user )(unsigned long)arg.dst_ptr;
	struct path path;
	struct inode *dir;
	struct dentry *victim;
	int ret = 0;

	if (arg.flags)
	return -EINVAL;

	victim = user_path_locked_at(arg.dirfd, name, &path);
	if (IS_ERR(victim))
	return PTR_ERR(victim);

	dir = d_inode(path.dentry);
	if (victim->d_sb->s_fs_info != c) {
	ret = -EXDEV;
	goto err;
	}

	ret = inode_permission(file_mnt_idmap(filp), d_inode(victim), MAY_WRITE) ?:
	__bch2_unlink(dir, victim, true);
	if (!ret) {
	fsnotify_rmdir(dir, victim);
	d_invalidate(victim);
	}
	err:
	inode_unlock(dir);
	dput(victim);
	path_put(&path);
	return ret;
	}

	long bch2_fs_file_ioctl(struct file *file, unsigned cmd, unsigned long arg)
	{
	struct bch_inode_info *inode = file_bch_inode(file);
	struct bch_fs *c = inode->v.i_sb->s_fs_info;
	long ret;

	switch (cmd) {
	case BCHFS_IOC_REINHERIT_ATTRS:
	ret = bch2_ioc_reinherit_attrs(c, file, inode,
	(void __user *) arg);
	break;

	case FS_IOC_GETVERSION:
	ret = bch2_ioc_getversion(inode, (u32 __user *) arg);
	break;

	case FS_IOC_SETVERSION:
	ret = -ENOTTY;
	break;

	case FS_IOC_GETFSLABEL:
	ret = bch2_ioc_getlabel(c, (void __user *) arg);
	break;

	case FS_IOC_SETFSLABEL:
	ret = bch2_ioc_setlabel(c, file, inode, (const void __user *) arg);
	break;

	case FS_IOC_GOINGDOWN:
	ret = bch2_ioc_goingdown(c, (u32 __user *) arg);
	break;

	case BCH_IOCTL_SUBVOLUME_CREATE: {
	struct bch_ioctl_subvolume i;

	ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
	? -EFAULT
	: bch2_ioctl_subvolume_create(c, file, i);
	break;
	}

	case BCH_IOCTL_SUBVOLUME_DESTROY: {
	struct bch_ioctl_subvolume i;

	ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
	? -EFAULT
	: bch2_ioctl_subvolume_destroy(c, file, i);
	break;
	}

	default:
	ret = bch2_fs_ioctl(c, cmd, (void __user *) arg);
	break;
	}

	return bch2_err_class(ret);
	}

	#ifdef CONFIG_COMPAT
	long bch2_compat_fs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
	{
	/* These are just misnamed, they actually get/put from/to user an int */
	switch (cmd) {
	case FS_IOC32_GETFLAGS:
	cmd = FS_IOC_GETFLAGS;
	break;
	case FS_IOC32_SETFLAGS:
	cmd = FS_IOC_SETFLAGS;
	break;
	case FS_IOC32_GETVERSION:
	cmd = FS_IOC_GETVERSION;
	break;
	case FS_IOC_GETFSLABEL:
	case FS_IOC_SETFSLABEL:
	break;
	default:
	return -ENOIOCTLCMD;
	}
	return bch2_fs_file_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
	}
	#endif

	#endif /* NO_BCACHEFS_FS */