From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id E24057F54 for ; Tue, 3 Sep 2013 13:25:50 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id D0AE9304082 for ; Tue, 3 Sep 2013 11:25:47 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id DlI5Vz8UOi9lfiM1 for ; Tue, 03 Sep 2013 11:25:47 -0700 (PDT) Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r83IPkQm031727 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 3 Sep 2013 14:25:46 -0400 Received: from bfoster.bfoster ([10.18.41.237]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r83IPkxp005897 for ; Tue, 3 Sep 2013 14:25:46 -0400 From: Brian Foster Subject: [RFC PATCH 02/11] xfs: reserve v5 superblock read-only compat. feature bit for finobt Date: Tue, 3 Sep 2013 14:24:59 -0400 Message-Id: <1378232708-57156-3-git-send-email-bfoster@redhat.com> In-Reply-To: <1378232708-57156-1-git-send-email-bfoster@redhat.com> References: <1378232708-57156-1-git-send-email-bfoster@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Reserve a v5 read-only compatibility feature bit for the finobt and create the xfs_sb_version_hasfinobt() helper to determine whether an fs has the feature enabled. The finobt does not change existing on-disk structures, but must remain consistent with the ialloc btree. Modifications from older kernels would violate that constrant. Therefore, we restrict older kernels to read-only mounts of finobt-enabled filesystems. Signed-off-by: Brian Foster --- fs/xfs/xfs_sb.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_sb.h b/fs/xfs/xfs_sb.h index 6835b44..c48d95d 100644 --- a/fs/xfs/xfs_sb.h +++ b/fs/xfs/xfs_sb.h @@ -585,7 +585,9 @@ xfs_sb_has_compat_feature( return (sbp->sb_features_compat & feature) != 0; } -#define XFS_SB_FEAT_RO_COMPAT_ALL 0 +#define XFS_SB_FEAT_RO_COMPAT_FINOBT (1 << 0) /* free inode btree */ +#define XFS_SB_FEAT_RO_COMPAT_ALL \ + (XFS_SB_FEAT_RO_COMPAT_FINOBT) #define XFS_SB_FEAT_RO_COMPAT_UNKNOWN ~XFS_SB_FEAT_RO_COMPAT_ALL static inline bool xfs_sb_has_ro_compat_feature( @@ -639,6 +641,12 @@ static inline int xfs_sb_version_hasftype(struct xfs_sb *sbp) (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE)); } +static inline int xfs_sb_version_hasfinobt(xfs_sb_t *sbp) +{ + return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) && + (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT); +} + /* * end of superblock version macros */ -- 1.8.1.4 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs