diff options
Diffstat (limited to 'fs/bcachefs/fs-ioctl.c')
-rw-r--r-- | fs/bcachefs/fs-ioctl.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/fs/bcachefs/fs-ioctl.c b/fs/bcachefs/fs-ioctl.c index 91f52ab9b4e2..ae402d350d4c 100644 --- a/fs/bcachefs/fs-ioctl.c +++ b/fs/bcachefs/fs-ioctl.c @@ -10,7 +10,11 @@ #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 */ @@ -292,6 +296,154 @@ err: 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 = -ENOENT; + 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 = to_bch_ei(dir)->ei_inode.bi_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_destroy(struct bch_fs *c, struct file *filp, + struct bch_ioctl_subvolume arg) +{ + struct path path; + 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) { + path_put(&path); + return -EXDEV; + } + + ret = __bch2_unlink(path.dentry->d_parent->d_inode, path.dentry, 1); + 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); @@ -322,6 +474,22 @@ long bch2_fs_file_ioctl(struct file *file, unsigned cmd, unsigned long arg) case FS_IOC_GOINGDOWN: return bch2_ioc_goingdown(c, (u32 __user *) arg); + case BCH_IOCTL_SUBVOLUME_CREATE: { + struct bch_ioctl_subvolume i; + + if (copy_from_user(&i, (void __user *) arg, sizeof(i))) + return -EFAULT; + return bch2_ioctl_subvolume_create(c, file, i); + } + + case BCH_IOCTL_SUBVOLUME_DESTROY: { + struct bch_ioctl_subvolume i; + + if (copy_from_user(&i, (void __user *) arg, sizeof(i))) + return -EFAULT; + return bch2_ioctl_subvolume_destroy(c, file, i); + } + default: return bch2_fs_ioctl(c, cmd, (void __user *) arg); } |