From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Sun, 30 Mar 2008 20:03:15 -0700 (PDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.168.28]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m2V337L4017874 for ; Sun, 30 Mar 2008 20:03:08 -0700 Received: from sandeen.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 5EDC88CA46E for ; Sun, 30 Mar 2008 20:03:42 -0700 (PDT) Received: from sandeen.net (sandeen.net [209.173.210.139]) by cuda.sgi.com with ESMTP id R24Tv8210m3su3k4 for ; Sun, 30 Mar 2008 20:03:42 -0700 (PDT) Received: from liberator.sandeen.net (liberator.sandeen.net [10.0.0.4]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by sandeen.net (Postfix) with ESMTP id 0BA94180307E3 for ; Sun, 30 Mar 2008 22:03:09 -0500 (CDT) Message-ID: <47F0546C.9070709@sandeen.net> Date: Sun, 30 Mar 2008 22:03:08 -0500 From: Eric Sandeen MIME-Version: 1.0 Subject: [PATCH] combined features2 fixup patches (updating/rewriting what was sent in other threads) Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: xfs-oss Ensure "both" features2 slots are consistent, and set mp attr2 flag. Since older kernels may look in the sb_bad_features2 slot for flags, rather than zeroing it out on fixup, we should make it equal to the sb_features2 value. Also, if the ATTR2 flag was not found prior to features2 fixup, it was not set in the mount flags, so re-check after the fixup so that the current session will use the feature. Also fix up the comments to reflect these changes. Signed-off-by: Eric Sandeen --- Index: linux-2.6-xfs/fs/xfs/xfs_mount.c =================================================================== --- linux-2.6-xfs.orig/fs/xfs/xfs_mount.c +++ linux-2.6-xfs/fs/xfs/xfs_mount.c @@ -967,22 +967,26 @@ xfs_mountfs( xfs_mount_common(mp, sbp); /* - * Check for a bad features2 field alignment. This happened on - * some platforms due to xfs_sb_t not being 64bit size aligned - * when sb_features was added and hence the compiler put it in - * the wrong place. + * Check for a mismatched features2 values. Older kernels + * read & wrote into the wrong sb offset for sb_features2 + * on some platforms due to xfs_sb_t not being 64bit size aligned + * when sb_features2 was added, which made older superblock + * reading/writing routines swap it as a 64-bit value. * - * If we detect a bad field, we or the set bits into the existing - * features2 field in case it has already been modified and we - * don't want to lose any features. Zero the bad one and mark - * the two fields as needing updates once the transaction subsystem - * is online. + * For backwards compatibility, we make both slots equal. + * + * If we detect a mismatched field, we OR the set bits into the + * existing features2 field in case it has already been modified; we + * don't want to lose any features. We then update the bad location + * with the ORed value so that older kernels will see any features2 + * flags, and mark the two fields as needing updates once the + * transaction subsystem is online. */ - if (xfs_sb_has_bad_features2(sbp)) { + if (xfs_sb_has_mismatched_features2(sbp)) { cmn_err(CE_WARN, "XFS: correcting sb_features alignment problem"); sbp->sb_features2 |= sbp->sb_bad_features2; - sbp->sb_bad_features2 = 0; + sbp->sb_bad_features2 = sbp->sb_features2; update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2; } @@ -1181,6 +1185,12 @@ xfs_mountfs( xfs_mount_log_sb(mp, update_flags); /* + * Re-check for ATTR2 in case it was found in bad_features2 slot. + */ + if (xfs_sb_version_hasattr2(&mp->m_sb)) + mp->m_flags |= XFS_MOUNT_ATTR2; + + /* * Initialise the XFS quota management subsystem for this mount */ error = XFS_QM_INIT(mp, "amount, "aflags); @@ -1890,7 +1900,8 @@ xfs_uuid_unmount( /* * Used to log changes to the superblock unit and width fields which could - * be altered by the mount options. Only the first superblock is updated. + * be altered by the mount options, as well as any potential sb_features2 + * fixup. Only the first superblock is updated. */ STATIC void xfs_mount_log_sb( Index: linux-2.6-xfs/fs/xfs/xfs_sb.h =================================================================== --- linux-2.6-xfs.orig/fs/xfs/xfs_sb.h +++ linux-2.6-xfs/fs/xfs/xfs_sb.h @@ -320,11 +320,12 @@ static inline int xfs_sb_good_version(xf #endif /* __KERNEL__ */ /* - * Detect a bad features2 field + * Detect a mismatched features2 field. Older kernels read/wrote + * this into the wrong slot, so to be safe we keep them in sync. */ -static inline int xfs_sb_has_bad_features2(xfs_sb_t *sbp) +static inline int xfs_sb_has_mismatched_features2(xfs_sb_t *sbp) { - return (sbp->sb_bad_features2 != 0); + return (sbp->sb_bad_features2 != sbp->sb_features2); } static inline unsigned xfs_sb_version_tonew(unsigned v)