On 03/15/2018 09:13 AM, Misono, Tomohiro wrote: > This is a preparetion work to allow normal user to call > "subvolume list/show". > > Signed-off-by: Tomohiro Misono <misono.tomoh...@jp.fujitsu.com> > --- > btrfs-list.c | 33 +++++++++++++++++++++++++++++++++ > btrfs-list.h | 1 + > 2 files changed, 34 insertions(+) > > diff --git a/btrfs-list.c b/btrfs-list.c > index 50e5ce5f..88689a9d 100644 > --- a/btrfs-list.c > +++ b/btrfs-list.c > @@ -958,6 +958,39 @@ out: > return 0; > } > > +/* > + * Check the permission for tree search ioctl by searching a key > + * which alwasys exists > + */ > +int check_perm_for_tree_search(int fd) > +{
In what this is different from '(getuid() == 0)' ? Which would be the cases where an error different from EPERM would be returned (other than the filesystem is not a BTRFS one )? I am not against to this kind of function. However with this implementation is not clear its behavior: - does it check if the user has enough privileges to perform a BTRFS_IOC_TREE_SEARCH or - does it check if BTRFS_IOC_TREE_SEARCH might return some error ? If the former, I would put this function into utils.[hc] checking only the [e]uid of the user. If the latter the name is confusing... > + struct btrfs_ioctl_search_args args; > + struct btrfs_ioctl_search_key *sk = &args.key; > + int ret; > + > + memset(&args, 0, sizeof(args)); > + sk->tree_id = BTRFS_ROOT_TREE_OBJECTID; > + sk->min_objectid = BTRFS_EXTENT_TREE_OBJECTID; > + sk->max_objectid = BTRFS_EXTENT_TREE_OBJECTID; > + sk->min_type = BTRFS_ROOT_ITEM_KEY; > + sk->max_type = BTRFS_ROOT_ITEM_KEY; > + sk->min_offset = 0; > + sk->max_offset = (u64)-1; > + sk->min_transid = 0; > + sk->max_transid = (u64)-1; > + sk->nr_items = 1; > + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args); > + > + if (!ret) > + ret = 1; > + else if (ret < 0 && errno == EPERM) > + ret = 0; > + else > + ret = -errno; > + > + return ret; > +} > + > static int list_subvol_search(int fd, struct root_lookup *root_lookup) > { > int ret; > diff --git a/btrfs-list.h b/btrfs-list.h > index 6e5fc778..6225311d 100644 > --- a/btrfs-list.h > +++ b/btrfs-list.h > @@ -176,5 +176,6 @@ char *btrfs_list_path_for_root(int fd, u64 root); > int btrfs_list_get_path_rootid(int fd, u64 *treeid); > int btrfs_get_subvol(int fd, struct root_info *the_ri); > int btrfs_get_toplevel_subvol(int fd, struct root_info *the_ri); > +int check_perm_for_tree_search(int fd); > > #endif > -- gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html