1 files changed, 562 insertions, 0 deletions

diff --git a/c_src/libbcachefs/fs-ioctl.c b/c_src/libbcachefs/fs-ioctl.c
new file mode 100644
index 00000000..e0a19a73
--- /dev/null
+++ b/c_src/libbcachefs/fs-ioctl.c
@@ -0,0 +1,562 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef NO_BCACHEFS_FS
+
+#include "bcachefs.h"
+#include "chardev.h"
+#include "dirent.h"
+#include "fs.h"
+#include "fs-common.h"
+#include "fs-ioctl.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 */
+
+struct flags_set {
+	unsigned		mask;
+	unsigned		flags;
+
+	unsigned		projid;
+
+	bool			set_projinherit;
+	bool			projinherit;
+};
+
+static int bch2_inode_flags_set(struct btree_trans *trans,
+				struct bch_inode_info *inode,
+				struct bch_inode_unpacked *bi,
+				void *p)
+{
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	/*
+	 * We're relying on btree locking here for exclusion with other ioctl
+	 * calls - use the flags in the btree (@bi), not inode->i_flags:
+	 */
+	struct flags_set *s = p;
+	unsigned newflags = s->flags;
+	unsigned oldflags = bi->bi_flags & s->mask;
+
+	if (((newflags ^ oldflags) & (BCH_INODE_append|BCH_INODE_immutable)) &&
+	    !capable(CAP_LINUX_IMMUTABLE))
+		return -EPERM;
+
+	if (!S_ISREG(bi->bi_mode) &&
+	    !S_ISDIR(bi->bi_mode) &&
+	    (newflags & (BCH_INODE_nodump|BCH_INODE_noatime)) != newflags)
+		return -EINVAL;
+
+	if (s->set_projinherit) {
+		bi->bi_fields_set &= ~(1 << Inode_opt_project);
+		bi->bi_fields_set |= ((int) s->projinherit << Inode_opt_project);
+	}
+
+	bi->bi_flags &= ~s->mask;
+	bi->bi_flags |= newflags;
+
+	bi->bi_ctime = timespec_to_bch2_time(c, current_time(&inode->v));
+	return 0;
+}
+
+static int bch2_ioc_getflags(struct bch_inode_info *inode, int __user *arg)
+{
+	unsigned flags = map_flags(bch_flags_to_uflags, inode->ei_inode.bi_flags);
+
+	return put_user(flags, arg);
+}
+
+static int bch2_ioc_setflags(struct bch_fs *c,
+			     struct file *file,
+			     struct bch_inode_info *inode,
+			     void __user *arg)
+{
+	struct flags_set s = { .mask = map_defined(bch_flags_to_uflags) };
+	unsigned uflags;
+	int ret;
+
+	if (get_user(uflags, (int __user *) arg))
+		return -EFAULT;
+
+	s.flags = map_flags_rev(bch_flags_to_uflags, uflags);
+	if (uflags)
+		return -EOPNOTSUPP;
+
+	ret = mnt_want_write_file(file);
+	if (ret)
+		return ret;
+
+	inode_lock(&inode->v);
+	if (!inode_owner_or_capable(file_mnt_idmap(file), &inode->v)) {
+		ret = -EACCES;
+		goto setflags_out;
+	}
+
+	mutex_lock(&inode->ei_update_lock);
+	ret   = bch2_subvol_is_ro(c, inode->ei_subvol) ?:
+		bch2_write_inode(c, inode, bch2_inode_flags_set, &s,
+			       ATTR_CTIME);
+	mutex_unlock(&inode->ei_update_lock);
+
+setflags_out:
+	inode_unlock(&inode->v);
+	mnt_drop_write_file(file);
+	return ret;
+}
+
+static int bch2_ioc_fsgetxattr(struct bch_inode_info *inode,
+			       struct fsxattr __user *arg)
+{
+	struct fsxattr fa = { 0 };
+
+	fa.fsx_xflags = map_flags(bch_flags_to_xflags, inode->ei_inode.bi_flags);
+
+	if (inode->ei_inode.bi_fields_set & (1 << Inode_opt_project))
+		fa.fsx_xflags |= FS_XFLAG_PROJINHERIT;
+
+	fa.fsx_projid = inode->ei_qid.q[QTYP_PRJ];
+
+	if (copy_to_user(arg, &fa, sizeof(fa)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int fssetxattr_inode_update_fn(struct btree_trans *trans,
+				      struct bch_inode_info *inode,
+				      struct bch_inode_unpacked *bi,
+				      void *p)
+{
+	struct flags_set *s = p;
+
+	if (s->projid != bi->bi_project) {
+		bi->bi_fields_set |= 1U << Inode_opt_project;
+		bi->bi_project = s->projid;
+	}
+
+	return bch2_inode_flags_set(trans, inode, bi, p);
+}
+
+static int bch2_ioc_fssetxattr(struct bch_fs *c,
+			       struct file *file,
+			       struct bch_inode_info *inode,
+			       struct fsxattr __user *arg)
+{
+	struct flags_set s = { .mask = map_defined(bch_flags_to_xflags) };
+	struct fsxattr fa;
+	int ret;
+
+	if (copy_from_user(&fa, arg, sizeof(fa)))
+		return -EFAULT;
+
+	s.set_projinherit = true;
+	s.projinherit = (fa.fsx_xflags & FS_XFLAG_PROJINHERIT) != 0;
+	fa.fsx_xflags &= ~FS_XFLAG_PROJINHERIT;
+
+	s.flags = map_flags_rev(bch_flags_to_xflags, fa.fsx_xflags);
+	if (fa.fsx_xflags)
+		return -EOPNOTSUPP;
+
+	if (fa.fsx_projid >= U32_MAX)
+		return -EINVAL;
+
+	/*
+	 * inode fields accessible via the xattr interface are stored with a +1
+	 * bias, so that 0 means unset:
+	 */
+	s.projid = fa.fsx_projid + 1;
+
+	ret = mnt_want_write_file(file);
+	if (ret)
+		return ret;
+
+	inode_lock(&inode->v);
+	if (!inode_owner_or_capable(file_mnt_idmap(file), &inode->v)) {
+		ret = -EACCES;
+		goto err;
+	}
+
+	mutex_lock(&inode->ei_update_lock);
+	ret   = bch2_subvol_is_ro(c, inode->ei_subvol) ?:
+		bch2_set_projid(c, inode, fa.fsx_projid) ?:
+		bch2_write_inode(c, inode, fssetxattr_inode_update_fn, &s,
+			       ATTR_CTIME);
+	mutex_unlock(&inode->ei_update_lock);
+err:
+	inode_unlock(&inode->v);
+	mnt_drop_write_file(file);
+	return ret;
+}
+
+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 + 1, 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_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 = freeze_bdev(c->vfs_sb->s_bdev);
+		if (ret)
+			break;
+		bch2_journal_flush(&c->journal);
+		bch2_fs_emergency_read_only(c);
+		thaw_bdev(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;
+
+	/* why do we need this lock? */
+	down_read(&c->vfs_sb->s_umount);
+
+	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
+		sync_inodes_sb(c->vfs_sb);
+retry:
+	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 = -EEXIST;
+		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;
+
+	inode = __bch2_create(file_mnt_idmap(filp), to_bch_ei(dir),
+			      dst_dentry, arg.mode|S_IFDIR,
+			      0, snapshot_src, create_flags);
+	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);
+
+	if (retry_estale(error, lookup_flags)) {
+		lookup_flags |= LOOKUP_REVAL;
+		goto retry;
+	}
+err1:
+	up_read(&c->vfs_sb->s_umount);
+
+	return error;
+}
+
+static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
+					struct bch_ioctl_subvolume arg)
+{
+	down_write(&c->snapshot_create_lock);
+	long ret = __bch2_ioctl_subvolume_create(c, filp, arg);
+	up_write(&c->snapshot_create_lock);
+
+	return ret;
+}
+
+static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
+				struct bch_ioctl_subvolume arg)
+{
+	struct path path;
+	struct inode *dir;
+	int ret = 0;
+
+	if (arg.flags)
+		return -EINVAL;
+
+	ret = user_path_at(arg.dirfd,
+			(const char __user *)(unsigned long)arg.dst_ptr,
+			LOOKUP_FOLLOW, &path);
+	if (ret)
+		return ret;
+
+	if (path.dentry->d_sb->s_fs_info != c) {
+		ret = -EXDEV;
+		goto err;
+	}
+
+	dir = path.dentry->d_parent->d_inode;
+
+	ret = __bch2_unlink(dir, path.dentry, true);
+	if (ret)
+		goto err;
+
+	fsnotify_rmdir(dir, path.dentry);
+	d_delete(path.dentry);
+err:
+	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 FS_IOC_GETFLAGS:
+		ret = bch2_ioc_getflags(inode, (int __user *) arg);
+		break;
+
+	case FS_IOC_SETFLAGS:
+		ret = bch2_ioc_setflags(c, file, inode, (int __user *) arg);
+		break;
+
+	case FS_IOC_FSGETXATTR:
+		ret = bch2_ioc_fsgetxattr(inode, (void __user *) arg);
+		break;
+
+	case FS_IOC_FSSETXATTR:
+		ret = bch2_ioc_fssetxattr(c, file, inode,
+					  (void __user *) arg);
+		break;
+
+	case BCHFS_IOC_REINHERIT_ATTRS:
+		ret = bch2_ioc_reinherit_attrs(c, file, inode,
+					       (void __user *) arg);
+		break;
+
+	case FS_IOC_GETVERSION:
+		ret = -ENOTTY;
+		break;
+
+	case FS_IOC_SETVERSION:
+		ret = -ENOTTY;
+		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_IOC_GETFLAGS:
+		cmd = FS_IOC_GETFLAGS;
+		break;
+	case FS_IOC32_SETFLAGS:
+		cmd = FS_IOC_SETFLAGS;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return bch2_fs_file_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif
+
+#endif /* NO_BCACHEFS_FS */