diff options
| -rw-r--r-- | fs/btrfs/ctree.h | 4 | ||||
| -rw-r--r-- | fs/btrfs/ioctl.c | 75 | ||||
| -rw-r--r-- | fs/btrfs/ioctl.h | 2 |
3 files changed, 80 insertions, 1 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 07d956977a07..1166b15e9bf6 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -373,11 +373,13 @@ struct btrfs_super_block { * ones specified below then we will fail to mount */ #define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF (1ULL << 0) +#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (2ULL << 0) #define BTRFS_FEATURE_COMPAT_SUPP 0ULL #define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL #define BTRFS_FEATURE_INCOMPAT_SUPP \ - BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF + (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \ + BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL) /* * A leaf is full of items. offset and size tell us where to find diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index c6044733198d..7875a75315d0 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1579,6 +1579,79 @@ out: return ret; } +static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) +{ + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_root *new_root; + struct btrfs_dir_item *di; + struct btrfs_trans_handle *trans; + struct btrfs_path *path; + struct btrfs_key location; + struct btrfs_disk_key disk_key; + struct btrfs_super_block *disk_super; + u64 features; + u64 objectid = 0; + u64 dir_id; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (copy_from_user(&objectid, argp, sizeof(objectid))) + return -EFAULT; + + if (!objectid) + objectid = root->root_key.objectid; + + location.objectid = objectid; + location.type = BTRFS_ROOT_ITEM_KEY; + location.offset = (u64)-1; + + new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); + if (IS_ERR(new_root)) + return PTR_ERR(new_root); + + if (btrfs_root_refs(&new_root->root_item) == 0) + return -ENOENT; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->leave_spinning = 1; + + trans = btrfs_start_transaction(root, 1); + if (!trans) { + btrfs_free_path(path); + return -ENOMEM; + } + + dir_id = btrfs_super_root_dir(&root->fs_info->super_copy); + di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path, + dir_id, "default", 7, 1); + if (!di) { + btrfs_free_path(path); + btrfs_end_transaction(trans, root); + printk(KERN_ERR "Umm, you don't have the default dir item, " + "this isn't going to work\n"); + return -ENOENT; + } + + btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key); + btrfs_set_dir_item_key(path->nodes[0], di, &disk_key); + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_free_path(path); + + disk_super = &root->fs_info->super_copy; + features = btrfs_super_incompat_flags(disk_super); + if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) { + features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL; + btrfs_set_super_incompat_flags(disk_super, features); + } + btrfs_end_transaction(trans, root); + + return 0; +} + /* * there are many ways the trans_start and trans_end ioctls can lead * to deadlocks. They should only be used by applications that @@ -1625,6 +1698,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_snap_create(file, argp, 1); case BTRFS_IOC_SNAP_DESTROY: return btrfs_ioctl_snap_destroy(file, argp); + case BTRFS_IOC_DEFAULT_SUBVOL: + return btrfs_ioctl_default_subvol(file, argp); case BTRFS_IOC_DEFRAG: return btrfs_ioctl_defrag(file); case BTRFS_IOC_RESIZE: diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 79c07b104f91..f1923e0260e3 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -1,3 +1,4 @@ + /* * Copyright (C) 2007 Oracle. All rights reserved. * @@ -133,4 +134,5 @@ struct btrfs_ioctl_clone_range_args { struct btrfs_ioctl_search_args) #define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \ struct btrfs_ioctl_ino_lookup_args) +#define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, u64) #endif |