From patchwork Mon Oct 7 09:11:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Thumshirn X-Patchwork-Id: 11177015 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6DD8A1599 for ; Mon, 7 Oct 2019 09:11:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 565402133F for ; Mon, 7 Oct 2019 09:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727505AbfJGJLK (ORCPT ); Mon, 7 Oct 2019 05:11:10 -0400 Received: from mx2.suse.de ([195.135.220.15]:38388 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727472AbfJGJLJ (ORCPT ); Mon, 7 Oct 2019 05:11:09 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 72D78B19B; Mon, 7 Oct 2019 09:11:07 +0000 (UTC) From: Johannes Thumshirn To: David Sterba Cc: Linux BTRFS Mailinglist , Nikolay Borisov , Johannes Thumshirn Subject: [PATCH 3/4] btrfs: sysfs: export supported checksums Date: Mon, 7 Oct 2019 11:11:03 +0200 Message-Id: <20191007091104.18095-4-jthumshirn@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20191007091104.18095-1-jthumshirn@suse.de> References: <20191007091104.18095-1-jthumshirn@suse.de> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: David Sterba Export supported checksum algorithms via sysfs. Co-developed-by: David Sterba Signed-off-by: Johannes Thumshirn --- fs/btrfs/ctree.c | 5 +++++ fs/btrfs/ctree.h | 2 ++ fs/btrfs/sysfs.c | 33 +++++++++++++++++++++++++++++++++ 3 files changed, 40 insertions(+) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index b66509ee62eb..5debd74dc61c 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -53,6 +53,11 @@ const char *btrfs_super_csum_name(u16 csum_type) return btrfs_csums[csum_type].name; } +size_t btrfs_get_num_csums(void) +{ + return ARRAY_SIZE(btrfs_csums); +} + struct btrfs_path *btrfs_alloc_path(void) { return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index d17e79a40930..0180554f6970 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2165,6 +2165,8 @@ BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block, int btrfs_super_csum_size(const struct btrfs_super_block *s); const char *btrfs_super_csum_name(u16 csum_type); +size_t btrfs_get_num_csums(void); + /* * The leaf data grows from end-to-front in the node. diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index f6d3c80f2e28..aeebbdfe1a98 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -246,6 +246,28 @@ static umode_t btrfs_feature_visible(struct kobject *kobj, return mode; } +static ssize_t btrfs_supported_checksums_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + ssize_t ret = 0; + int i; + + for (i = 0; i < btrfs_get_num_csums(); i++) { + /* + * This "trick" only works as long as 'enum btrfs_csum_type' has + * no holes in it + */ + ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s", + (i == 0 ? "" : ", "), + btrfs_super_csum_name(i)); + + } + + ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n"); + return ret; +} + BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); @@ -259,6 +281,14 @@ BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES); BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID); BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE); +static struct btrfs_feature_attr btrfs_attr_features_checksums_name = { + .kobj_attr = __INIT_KOBJ_ATTR(supported_checksums, S_IRUGO, + btrfs_supported_checksums_show, + NULL), + .feature_set = FEAT_INCOMPAT, + .feature_bit = 0, +}; + static struct attribute *btrfs_supported_feature_attrs[] = { BTRFS_FEAT_ATTR_PTR(mixed_backref), BTRFS_FEAT_ATTR_PTR(default_subvol), @@ -272,6 +302,9 @@ static struct attribute *btrfs_supported_feature_attrs[] = { BTRFS_FEAT_ATTR_PTR(no_holes), BTRFS_FEAT_ATTR_PTR(metadata_uuid), BTRFS_FEAT_ATTR_PTR(free_space_tree), + + &btrfs_attr_features_checksums_name.kobj_attr.attr, + NULL };