On 2018/08/12 10:33, Qu Wenruo wrote: > Provide an offline tool to disable quota. > > For kernel which skip_balance doesn't work, there is no way to disable > quota on huge fs with balance, as quota will cause balance to hang for a > long long time for each tree block switch. > > So add an offline rescue tool to disable quota. > > Reported-by: Dan Merillat <dan.merillat@xxxxxxxxx> > Signed-off-by: Qu Wenruo <wqu@xxxxxxxx> > --- > This can patch can be fetched from github repo: > https://github.com/adam900710/btrfs-progs/tree/quota_disable > --- > Documentation/btrfs-rescue.asciidoc | 6 +++ > cmds-rescue.c | 80 +++++++++++++++++++++++++++++ > 2 files changed, 86 insertions(+) > > diff --git a/Documentation/btrfs-rescue.asciidoc b/Documentation/btrfs-rescue.asciidoc > index f94a0ff2b45e..fb088c1a768a 100644 > --- a/Documentation/btrfs-rescue.asciidoc > +++ b/Documentation/btrfs-rescue.asciidoc > @@ -31,6 +31,12 @@ help. > NOTE: Since *chunk-recover* will scan the whole device, it will be *VERY* slow > especially executed on a large device. > > +*disable-quota* <device>:: > +disable quota offline > ++ > +Acts as a fallback method to disable quota for case where mount hangs due to > +balance and quota. > + > *fix-device-size* <device>:: > fix device size and super block total bytes values that are do not match > + > diff --git a/cmds-rescue.c b/cmds-rescue.c > index 38c4ab9b2ef6..c7cd92427e9d 100644 > --- a/cmds-rescue.c > +++ b/cmds-rescue.c > @@ -250,6 +250,84 @@ out: > return !!ret; > } > > +static const char * const cmd_rescue_disable_quota_usage[] = { > + "btrfs rescue disable-quota <device>", > + "Disable quota, especially useful for balance mount hang when quota enabled", > + "", > + NULL > +}; > + > +static int cmd_rescue_disable_quota(int argc, char **argv) > +{ > + struct btrfs_trans_handle *trans; > + struct btrfs_fs_info *fs_info; > + struct btrfs_path path; > + struct btrfs_root *root; > + struct btrfs_qgroup_status_item *qi; > + struct btrfs_key key; > + char *devname; > + int ret; > + > + clean_args_no_options(argc, argv, cmd_rescue_disable_quota_usage); > + if (check_argc_exact(argc, 2)) > + usage(cmd_rescue_disable_quota_usage); > + > + devname = argv[optind]; > + ret = check_mounted(devname); > + if (ret < 0) { > + error("could not check mount status: %s", strerror(-ret)); > + return !!ret; > + } else if (ret) { > + error("%s is currently mounted", devname); > + return !!ret; > + } > + fs_info = open_ctree_fs_info(devname, 0, 0, 0, OPEN_CTREE_WRITES); > + if (!fs_info) { > + error("could not open btrfs"); > + ret = -EIO; > + return !!ret; > + } > + root = fs_info->quota_root; > + if (!root) { > + printf("Quota is not enabled, no need to modify the fs\n"); > + goto close; > + } > + btrfs_init_path(&path); > + trans = btrfs_start_transaction(root, 1); > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + error("failed to start transaction: %s", strerror(-ret)); > + goto close; > + } > + key.objectid = 0; > + key.type = BTRFS_QGROUP_STATUS_KEY; > + key.offset = 0; > + ret = btrfs_search_slot(trans, root, &key, &path, 0, 1); > + if (ret < 0) { > + error("failed to search tree: %s", strerror(-ret)); > + goto close; > + } > + if (ret > 0) { > + printf( > + "qgroup status item not found, not need to modify the fs"); > + ret = 0; > + goto release; > + } > + qi = btrfs_item_ptr(path.nodes[0], path.slots[0], > + struct btrfs_qgroup_status_item); > + btrfs_set_qgroup_status_flags(path.nodes[0], qi, > + BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT); This is not what "btrfs quota disable" does (completely removes quota tree), so I think it is better to have different name other than "disable-quota" (I'm not sure about good name, maybe suspend?). btw, maybe we should add this ability to online fs too so that we can temporally disable quota during balance while keeping limit/inheritance settings? Thanks, Misono > + btrfs_mark_buffer_dirty(path.nodes[0]); > + ret = btrfs_commit_transaction(trans, root); > + if (ret < 0) > + error("failed to commit transaction: %s", strerror(-ret)); > +release: > + btrfs_release_path(&path); > +close: > + close_ctree(fs_info->tree_root); > + return !!ret; > +} > + > static const char rescue_cmd_group_info[] = > "toolbox for specific rescue operations"; > > @@ -262,6 +340,8 @@ const struct cmd_group rescue_cmd_group = { > { "zero-log", cmd_rescue_zero_log, cmd_rescue_zero_log_usage, NULL, 0}, > { "fix-device-size", cmd_rescue_fix_device_size, > cmd_rescue_fix_device_size_usage, NULL, 0}, > + { "disable-quota", cmd_rescue_disable_quota, > + cmd_rescue_disable_quota_usage, NULL, 0}, > NULL_CMD_STRUCT > } > }; >
