From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:51767 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751507AbbFSFXa convert rfc822-to-8bit (ORCPT ); Fri, 19 Jun 2015 01:23:30 -0400 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t5J5LqNr032199 for ; Fri, 19 Jun 2015 13:21:52 +0800 Subject: Re: [PATCH v9 9/9] btrfs: Use sb_want_write() to protect sysfs feature change. To: References: <1424048525-26274-1-git-send-email-quwenruo@cn.fujitsu.com> <55559689.4090305@cn.fujitsu.com> From: Qu Wenruo Message-ID: <5583A74F.7010906@cn.fujitsu.com> Date: Fri, 19 Jun 2015 13:23:27 +0800 MIME-Version: 1.0 In-Reply-To: <55559689.4090305@cn.fujitsu.com> Content-Type: text/plain; charset="utf-8"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: OK, it's 4.2 merge windows now... But still no new comments? Thanks, Qu Qu Wenruo wrote on 2015/05/15 14:47 +0800: > Ping. > > Any comments? > Other v7 patchset is reviewed by David. > > But I didn't find it in 4.1 merge windows. > Is something wrong or we are waiting for the vfs patch merged first? > > Thanks, > Qu > > -------- Original Message -------- > Subject: [PATCH v9 9/9] btrfs: Use sb_want_write() to protect sysfs > feature change. > From: Qu Wenruo > To: > Date: 2015年02月16日 09:02 > >> Just like label change, use sb_want_write() to do a correct protection. >> >> Signed-off-by: Qu Wenruo >> --- >> v4: >> Newly introduced. >> v5: >> Change to sb_want_write(). >> v6: >> Move sb_want_write() to the beginning of the function. >> v7: >> None >> v8: >> Move sb_want_write() after get fs_info. >> v9: >> Fix a unpaired sb_drop_write() in error handler. >> --- >> fs/btrfs/sysfs.c | 25 +++++++++++++++++-------- >> 1 file changed, 17 insertions(+), 8 deletions(-) >> >> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c >> index 7e548f7..19876ba 100644 >> --- a/fs/btrfs/sysfs.c >> +++ b/fs/btrfs/sysfs.c >> @@ -121,10 +121,14 @@ static ssize_t btrfs_feature_attr_store(struct >> kobject *kobj, >> if (!fs_info) >> return -EPERM; >> >> - ret = kstrtoul(skip_spaces(buf), 0, &val); >> + ret = sb_want_write(fs_info->sb); >> if (ret) >> return ret; >> >> + ret = kstrtoul(skip_spaces(buf), 0, &val); >> + if (ret) >> + goto out; >> + >> if (fa->feature_set == FEAT_COMPAT) { >> set = BTRFS_FEATURE_COMPAT_SAFE_SET; >> clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; >> @@ -141,22 +145,25 @@ static ssize_t btrfs_feature_attr_store(struct >> kobject *kobj, >> /* Nothing to do */ >> if ((val && (features & fa->feature_bit)) || >> (!val && !(features & fa->feature_bit))) >> - return count; >> + goto out; >> >> if ((val && !(set & fa->feature_bit)) || >> (!val && !(clear & fa->feature_bit))) { >> btrfs_info(fs_info, >> "%sabling feature %s on mounted fs is not supported.", >> val ? "En" : "Dis", fa->kobj_attr.attr.name); >> - return -EPERM; >> + ret = -EPERM; >> + goto out; >> } >> >> btrfs_info(fs_info, "%s %s feature flag", >> val ? "Setting" : "Clearing", fa->kobj_attr.attr.name); >> >> trans = btrfs_start_transaction(fs_info->fs_root, 0); >> - if (IS_ERR(trans)) >> - return PTR_ERR(trans); >> + if (IS_ERR(trans)) { >> + ret = PTR_ERR(trans); >> + goto out; >> + } >> >> spin_lock(&fs_info->super_lock); >> features = get_features(fs_info, fa->feature_set); >> @@ -168,10 +175,12 @@ static ssize_t btrfs_feature_attr_store(struct >> kobject *kobj, >> spin_unlock(&fs_info->super_lock); >> >> ret = btrfs_commit_transaction(trans, fs_info->fs_root); >> - if (ret) >> - return ret; >> >> - return count; >> +out: >> + sb_drop_write(fs_info->sb); >> + if (!ret) >> + return count; >> + return ret; >> } >> >> static umode_t btrfs_feature_visible(struct kobject *kobj, >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html