Merge branch 'xfs-feature-bit-cleanup' into for-next

Conflicts:
	fs/xfs/xfs_inode.c

11 files changed, 101 insertions, 327 deletions

diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c
index e365c98..93fcebd 100644
--- a/fs/xfs/xfs_dir2.c
+++ b/fs/xfs/xfs_dir2.c
@@ -92,7 +92,7 @@ xfs_dir_mount(
 	int	nodehdr_size;
 
 
-	ASSERT(xfs_sb_version_hasdirv2(&mp->m_sb));
+	ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
 	ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
 	       XFS_MAX_BLOCKSIZE);
 
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 3445ead..97886a7 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -74,23 +74,18 @@ xfs_fs_geometry(
 	}
 	if (new_version >= 3) {
 		geo->version = XFS_FSOP_GEOM_VERSION;
-		geo->flags =
+		geo->flags = XFS_FSOP_GEOM_FLAGS_NLINK |
+			     XFS_FSOP_GEOM_FLAGS_DIRV2 |
 			(xfs_sb_version_hasattr(&mp->m_sb) ?
 				XFS_FSOP_GEOM_FLAGS_ATTR : 0) |
-			(xfs_sb_version_hasnlink(&mp->m_sb) ?
-				XFS_FSOP_GEOM_FLAGS_NLINK : 0) |
 			(xfs_sb_version_hasquota(&mp->m_sb) ?
 				XFS_FSOP_GEOM_FLAGS_QUOTA : 0) |
 			(xfs_sb_version_hasalign(&mp->m_sb) ?
 				XFS_FSOP_GEOM_FLAGS_IALIGN : 0) |
 			(xfs_sb_version_hasdalign(&mp->m_sb) ?
 				XFS_FSOP_GEOM_FLAGS_DALIGN : 0) |
-			(xfs_sb_version_hasshared(&mp->m_sb) ?
-				XFS_FSOP_GEOM_FLAGS_SHARED : 0) |
 			(xfs_sb_version_hasextflgbit(&mp->m_sb) ?
 				XFS_FSOP_GEOM_FLAGS_EXTFLG : 0) |
-			(xfs_sb_version_hasdirv2(&mp->m_sb) ?
-				XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
 			(xfs_sb_version_hassector(&mp->m_sb) ?
 				XFS_FSOP_GEOM_FLAGS_SECTOR : 0) |
 			(xfs_sb_version_hasasciici(&mp->m_sb) ?
diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index 1313df7..e8dfaf0 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -280,10 +280,8 @@ xfs_ialloc_inode_init(
 		if (tp)
 			xfs_icreate_log(tp, agno, agbno, mp->m_ialloc_inos,
 					mp->m_sb.sb_inodesize, length, gen);
-	} else if (xfs_sb_version_hasnlink(&mp->m_sb))
+	} else
 		version = 2;
-	else
-		version = 1;
 
 	for (j = 0; j < nbufs; j++) {
 		/*
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 6d6b44a..a6115fe 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -681,6 +681,14 @@ xfs_ialloc(
 		return error;
 	ASSERT(ip != NULL);
 
+	/*
+	 * We always convert v1 inodes to v2 now - we only support filesystems
+	 * with >= v2 inode capability, so there is no reason for ever leaving
+	 * an inode in v1 format.
+	 */
+	if (ip->i_d.di_version == 1)
+		ip->i_d.di_version = 2;
+
 	ip->i_d.di_mode = mode;
 	ip->i_d.di_onlink = 0;
 	ip->i_d.di_nlink = nlink;
@@ -690,27 +698,6 @@ xfs_ialloc(
 	xfs_set_projid(ip, prid);
 	memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
 
-	/*
-	 * If the superblock version is up to where we support new format
-	 * inodes and this is currently an old format inode, then change
-	 * the inode version number now.  This way we only do the conversion
-	 * here rather than here and in the flush/logging code.
-	 */
-	if (xfs_sb_version_hasnlink(&mp->m_sb) &&
-	    ip->i_d.di_version == 1) {
-		ip->i_d.di_version = 2;
-		/*
-		 * We've already zeroed the old link count, the projid field,
-		 * and the pad field.
-		 */
-	}
-
-	/*
-	 * Project ids won't be stored on disk if we are using a version 1 inode.
-	 */
-	if ((prid != 0) && (ip->i_d.di_version == 1))
-		xfs_bump_ino_vers2(tp, ip);
-
 	if (pip && XFS_INHERIT_GID(pip)) {
 		ip->i_d.di_gid = pip->i_d.di_gid;
 		if ((pip->i_d.di_mode & S_ISGID) && S_ISDIR(mode)) {
@@ -1056,40 +1043,6 @@ xfs_droplink(
 }
 
 /*
- * This gets called when the inode's version needs to be changed from 1 to 2.
- * Currently this happens when the nlink field overflows the old 16-bit value
- * or when chproj is called to change the project for the first time.
- * As a side effect the superblock version will also get rev'd
- * to contain the NLINK bit.
- */
-void
-xfs_bump_ino_vers2(
-	xfs_trans_t	*tp,
-	xfs_inode_t	*ip)
-{
-	xfs_mount_t	*mp;
-
-	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
-	ASSERT(ip->i_d.di_version == 1);
-
-	ip->i_d.di_version = 2;
-	ip->i_d.di_onlink = 0;
-	memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
-	mp = tp->t_mountp;
-	if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
-		spin_lock(&mp->m_sb_lock);
-		if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
-			xfs_sb_version_addnlink(&mp->m_sb);
-			spin_unlock(&mp->m_sb_lock);
-			xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
-		} else {
-			spin_unlock(&mp->m_sb_lock);
-		}
-	}
-	/* Caller must log the inode */
-}
-
-/*
  * Increment the link count on an inode & log the change.
  */
 int
@@ -1099,22 +1052,10 @@ xfs_bumplink(
 {
 	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
 
+	ASSERT(ip->i_d.di_version > 1);
 	ASSERT(ip->i_d.di_nlink > 0 || (VFS_I(ip)->i_state & I_LINKABLE));
 	ip->i_d.di_nlink++;
 	inc_nlink(VFS_I(ip));
-	if ((ip->i_d.di_version == 1) &&
-	    (ip->i_d.di_nlink > XFS_MAXLINK_1)) {
-		/*
-		 * The inode has increased its number of links beyond
-		 * what can fit in an old format inode.  It now needs
-		 * to be converted to a version 2 inode with a 32 bit
-		 * link count.  If this is the first inode in the file
-		 * system to do this, then we need to bump the superblock
-		 * version number as well.
-		 */
-		xfs_bump_ino_vers2(tp, ip);
-	}
-
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 	return 0;
 }
@@ -3249,6 +3190,7 @@ xfs_iflush_int(
 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
 	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
 	ASSERT(iip != NULL && iip->ili_fields != 0);
+	ASSERT(ip->i_d.di_version > 1);
 
 	/* set *dip = inode's place in the buffer */
 	dip = (xfs_dinode_t *)xfs_buf_offset(bp, ip->i_imap.im_boffset);
@@ -3309,7 +3251,7 @@ xfs_iflush_int(
 	}
 
 	/*
-	 * Inode item log recovery for v1/v2 inodes are dependent on the
+	 * Inode item log recovery for v2 inodes are dependent on the
 	 * di_flushiter count for correct sequencing. We bump the flush
 	 * iteration count so we can detect flushes which postdate a log record
 	 * during recovery. This is redundant as we now log every change and
@@ -3332,37 +3274,6 @@ xfs_iflush_int(
 	if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
 		ip->i_d.di_flushiter = 0;
 
-	/*
-	 * If this is really an old format inode and the superblock version
-	 * has not been updated to support only new format inodes, then
-	 * convert back to the old inode format.  If the superblock version
-	 * has been updated, then make the conversion permanent.
-	 */
-	ASSERT(ip->i_d.di_version == 1 || xfs_sb_version_hasnlink(&mp->m_sb));
-	if (ip->i_d.di_version == 1) {
-		if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
-			/*
-			 * Convert it back.
-			 */
-			ASSERT(ip->i_d.di_nlink <= XFS_MAXLINK_1);
-			dip->di_onlink = cpu_to_be16(ip->i_d.di_nlink);
-		} else {
-			/*
-			 * The superblock version has already been bumped,
-			 * so just make the conversion to the new inode
-			 * format permanent.
-			 */
-			ip->i_d.di_version = 2;
-			dip->di_version = 2;
-			ip->i_d.di_onlink = 0;
-			dip->di_onlink = 0;
-			memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
-			memset(&(dip->di_pad[0]), 0,
-			      sizeof(dip->di_pad));
-			ASSERT(xfs_get_projid(ip) == 0);
-		}
-	}
-
 	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
 	if (XFS_IFORK_Q(ip))
 		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 13aea54..f72bffa 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -377,7 +377,6 @@ int		xfs_dir_ialloc(struct xfs_trans **, struct xfs_inode *, umode_t,
 			       struct xfs_inode **, int *);
 int		xfs_droplink(struct xfs_trans *, struct xfs_inode *);
 int		xfs_bumplink(struct xfs_trans *, struct xfs_inode *);
-void		xfs_bump_ino_vers2(struct xfs_trans *, struct xfs_inode *);
 
 /* from xfs_file.c */
 int		xfs_zero_eof(struct xfs_inode *, xfs_off_t, xfs_fsize_t);
diff --git a/fs/xfs/xfs_inode_buf.c b/fs/xfs/xfs_inode_buf.c
index 24e9939..cb35ae4 100644
--- a/fs/xfs/xfs_inode_buf.c
+++ b/fs/xfs/xfs_inode_buf.c
@@ -437,17 +437,16 @@ xfs_iread(
 	}
 
 	/*
-	 * The inode format changed when we moved the link count and
-	 * made it 32 bits long.  If this is an old format inode,
-	 * convert it in memory to look like a new one.  If it gets
-	 * flushed to disk we will convert back before flushing or
-	 * logging it.  We zero out the new projid field and the old link
-	 * count field.  We'll handle clearing the pad field (the remains
-	 * of the old uuid field) when we actually convert the inode to
-	 * the new format. We don't change the version number so that we
-	 * can distinguish this from a real new format inode.
+	 * Automatically convert version 1 inode formats in memory to version 2
+	 * inode format. If the inode is modified, it will get logged and
+	 * rewritten as a version 2 inode. We can do this because we set the
+	 * superblock feature bit for v2 inodes unconditionally during mount
+	 * and it means the reast of the code can assume the inode version is 2
+	 * or higher.
 	 */
 	if (ip->i_d.di_version == 1) {
+		ip->i_d.di_version = 2;
+		memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
 		ip->i_d.di_nlink = ip->i_d.di_onlink;
 		ip->i_d.di_onlink = 0;
 		xfs_set_projid(ip, 0);
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 686889b..a640137 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -145,34 +145,6 @@ xfs_inode_item_size(
 		xfs_inode_item_attr_fork_size(iip, nvecs, nbytes);
 }
 
-/*
- * If this is a v1 format inode, then we need to log it as such.  This means
- * that we have to copy the link count from the new field to the old.  We
- * don't have to worry about the new fields, because nothing trusts them as
- * long as the old inode version number is there.
- */
-STATIC void
-xfs_inode_item_format_v1_inode(
-	struct xfs_inode	*ip)
-{
-	if (!xfs_sb_version_hasnlink(&ip->i_mount->m_sb)) {
-		/*
-		 * Convert it back.
-		 */
-		ASSERT(ip->i_d.di_nlink <= XFS_MAXLINK_1);
-		ip->i_d.di_onlink = ip->i_d.di_nlink;
-	} else {
-		/*
-		 * The superblock version has already been bumped,
-		 * so just make the conversion to the new inode
-		 * format permanent.
-		 */
-		ip->i_d.di_version = 2;
-		ip->i_d.di_onlink = 0;
-		memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
-	}
-}
-
 STATIC void
 xfs_inode_item_format_data_fork(
 	struct xfs_inode_log_item *iip,
@@ -370,6 +342,8 @@ xfs_inode_item_format(
 	struct xfs_inode_log_format *ilf;
 	struct xfs_log_iovec	*vecp = NULL;
 
+	ASSERT(ip->i_d.di_version > 1);
+
 	ilf = xlog_prepare_iovec(lv, &vecp, XLOG_REG_TYPE_IFORMAT);
 	ilf->ilf_type = XFS_LI_INODE;
 	ilf->ilf_ino = ip->i_ino;
@@ -380,8 +354,6 @@ xfs_inode_item_format(
 	ilf->ilf_size = 2; /* format + core */
 	xlog_finish_iovec(lv, vecp, sizeof(struct xfs_inode_log_format));
 
-	if (ip->i_d.di_version == 1)
-		xfs_inode_item_format_v1_inode(ip);
 	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ICORE,
 			&ip->i_d,
 			xfs_icdinode_size(ip->i_d.di_version));
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 2d8f4fd..55724c8 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1228,15 +1228,8 @@ xfs_ioctl_setattr(
 				olddquot = xfs_qm_vop_chown(tp, ip,
 							&ip->i_pdquot, pdqp);
 			}
+			ASSERT(ip->i_d.di_version > 1);
 			xfs_set_projid(ip, fa->fsx_projid);
-
-			/*
-			 * We may have to rev the inode as well as
-			 * the superblock version number since projids didn't
-			 * exist before DINODE_VERSION_2 and SB_VERSION_NLINK.
-			 */
-			if (ip->i_d.di_version == 1)
-				xfs_bump_ino_vers2(tp, ip);
 		}
 
 	}
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 944f3d9..3f09782 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -697,6 +697,12 @@ xfs_mountfs(
 			mp->m_update_flags |= XFS_SB_VERSIONNUM;
 	}
 
+	/* always use v2 inodes by default now */
+	if (!(mp->m_sb.sb_versionnum & XFS_SB_VERSION_NLINKBIT)) {
+		mp->m_sb.sb_versionnum |= XFS_SB_VERSION_NLINKBIT;
+		mp->m_update_flags |= XFS_SB_VERSIONNUM;
+	}
+
 	/*
 	 * Check if sb_agblocks is aligned at stripe boundary
 	 * If sb_agblocks is NOT aligned turn off m_dalign since
diff --git a/fs/xfs/xfs_sb.c b/fs/xfs/xfs_sb.c
index 8baf61a..c3453b1 100644
--- a/fs/xfs/xfs_sb.c
+++ b/fs/xfs/xfs_sb.c
@@ -291,7 +291,8 @@ xfs_mount_validate_sb(
 	    (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)	||
 	    sbp->sb_dblocks == 0					||
 	    sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)			||
-	    sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp))) {
+	    sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)			||
+	    sbp->sb_shared_vn != 0)) {
 		xfs_notice(mp, "SB sanity check failed");
 		return XFS_ERROR(EFSCORRUPTED);
 	}
@@ -333,15 +334,6 @@ xfs_mount_validate_sb(
 		xfs_warn(mp, "Offline file system operation in progress!");
 		return XFS_ERROR(EFSCORRUPTED);
 	}
-
-	/*
-	 * Version 1 directory format has never worked on Linux.
-	 */
-	if (unlikely(!xfs_sb_version_hasdirv2(sbp))) {
-		xfs_warn(mp, "file system using version 1 directory format");
-		return XFS_ERROR(ENOSYS);
-	}
-
 	return 0;
 }
 
diff --git a/fs/xfs/xfs_sb.h b/fs/xfs/xfs_sb.h
index 950d1ea..c43c2d6 100644
--- a/fs/xfs/xfs_sb.h
+++ b/fs/xfs/xfs_sb.h
@@ -36,8 +36,6 @@ struct xfs_trans;
 #define	XFS_SB_VERSION_5	5		/* CRC enabled filesystem */
 #define	XFS_SB_VERSION_NUMBITS		0x000f
 #define	XFS_SB_VERSION_ALLFBITS		0xfff0
-#define	XFS_SB_VERSION_SASHFBITS	0xf000
-#define	XFS_SB_VERSION_REALFBITS	0x0ff0
 #define	XFS_SB_VERSION_ATTRBIT		0x0010
 #define	XFS_SB_VERSION_NLINKBIT		0x0020
 #define	XFS_SB_VERSION_QUOTABIT		0x0040
@@ -50,24 +48,15 @@ struct xfs_trans;
 #define	XFS_SB_VERSION_DIRV2BIT		0x2000
 #define	XFS_SB_VERSION_BORGBIT		0x4000	/* ASCII only case-insens. */
 #define	XFS_SB_VERSION_MOREBITSBIT	0x8000
-#define	XFS_SB_VERSION_OKSASHFBITS	\
-	(XFS_SB_VERSION_EXTFLGBIT | \
-	 XFS_SB_VERSION_DIRV2BIT | \
-	 XFS_SB_VERSION_BORGBIT)
-#define	XFS_SB_VERSION_OKREALFBITS	\
-	(XFS_SB_VERSION_ATTRBIT | \
-	 XFS_SB_VERSION_NLINKBIT | \
-	 XFS_SB_VERSION_QUOTABIT | \
-	 XFS_SB_VERSION_ALIGNBIT | \
-	 XFS_SB_VERSION_DALIGNBIT | \
-	 XFS_SB_VERSION_SHAREDBIT | \
-	 XFS_SB_VERSION_LOGV2BIT | \
-	 XFS_SB_VERSION_SECTORBIT | \
-	 XFS_SB_VERSION_MOREBITSBIT)
-#define	XFS_SB_VERSION_OKREALBITS	\
-	(XFS_SB_VERSION_NUMBITS | \
-	 XFS_SB_VERSION_OKREALFBITS | \
-	 XFS_SB_VERSION_OKSASHFBITS)
+
+/*
+ * Supported feature bit list is just all bits in the versionnum field because
+ * we've used them all up and understand them all. Except, of course, for the
+ * shared superblock bit, which nobody knows what it does and so is unsupported.
+ */
+#define	XFS_SB_VERSION_OKBITS		\
+	((XFS_SB_VERSION_NUMBITS | XFS_SB_VERSION_ALLFBITS) & \
+		~XFS_SB_VERSION_SHAREDBIT)
 
 /*
  * There are two words to hold XFS "feature" bits: the original
@@ -76,7 +65,6 @@ struct xfs_trans;
  *
  * These defines represent bits in sb_features2.
  */
-#define XFS_SB_VERSION2_REALFBITS	0x00ffffff	/* Mask: features */
 #define XFS_SB_VERSION2_RESERVED1BIT	0x00000001
 #define XFS_SB_VERSION2_LAZYSBCOUNTBIT	0x00000002	/* Superblk counters */
 #define XFS_SB_VERSION2_RESERVED4BIT	0x00000004
@@ -86,16 +74,11 @@ struct xfs_trans;
 #define XFS_SB_VERSION2_CRCBIT		0x00000100	/* metadata CRCs */
 #define XFS_SB_VERSION2_FTYPE		0x00000200	/* inode type in dir */
 
-#define	XFS_SB_VERSION2_OKREALFBITS	\
+#define	XFS_SB_VERSION2_OKBITS		\
 	(XFS_SB_VERSION2_LAZYSBCOUNTBIT	| \
 	 XFS_SB_VERSION2_ATTR2BIT	| \
 	 XFS_SB_VERSION2_PROJID32BIT	| \
 	 XFS_SB_VERSION2_FTYPE)
-#define	XFS_SB_VERSION2_OKSASHFBITS	\
-	(0)
-#define XFS_SB_VERSION2_OKREALBITS	\
-	(XFS_SB_VERSION2_OKREALFBITS |	\
-	 XFS_SB_VERSION2_OKSASHFBITS )
 
 /*
  * Superblock - in core version.  Must match the ondisk version below.
@@ -345,214 +328,140 @@ typedef enum {
 
 #define	XFS_SB_VERSION_NUM(sbp)	((sbp)->sb_versionnum & XFS_SB_VERSION_NUMBITS)
 
-static inline int xfs_sb_good_version(xfs_sb_t *sbp)
-{
-	/* We always support version 1-3 */
-	if (sbp->sb_versionnum >= XFS_SB_VERSION_1 &&
-	    sbp->sb_versionnum <= XFS_SB_VERSION_3)
-		return 1;
-
-	/* We support version 4 if all feature bits are supported */
-	if (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) {
-		if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKREALBITS) ||
-		    ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
-		     (sbp->sb_features2 & ~XFS_SB_VERSION2_OKREALBITS)))
-			return 0;
-
-		if (sbp->sb_shared_vn > XFS_SB_MAX_SHARED_VN)
-			return 0;
-		return 1;
-	}
-	if (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5)
-		return 1;
-
-	return 0;
-}
-
 /*
- * Detect a mismatched features2 field.  Older kernels read/wrote
- * this into the wrong slot, so to be safe we keep them in sync.
+ * The first XFS version we support is a v4 superblock with V2 directories.
  */
-static inline int xfs_sb_has_mismatched_features2(xfs_sb_t *sbp)
+static inline bool xfs_sb_good_v4_features(struct xfs_sb *sbp)
 {
-	return (sbp->sb_bad_features2 != sbp->sb_features2);
-}
+	if (!(sbp->sb_versionnum & XFS_SB_VERSION_DIRV2BIT))
+		return false;
 
-static inline unsigned xfs_sb_version_tonew(unsigned v)
-{
-	if (v == XFS_SB_VERSION_1)
-		return XFS_SB_VERSION_4;
+	/* check for unknown features in the fs */
+	if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
+	    ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
+	     (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS)))
+		return false;
 
-	if (v == XFS_SB_VERSION_2)
-		return XFS_SB_VERSION_4 | XFS_SB_VERSION_ATTRBIT;
-
-	return XFS_SB_VERSION_4 | XFS_SB_VERSION_ATTRBIT |
-		XFS_SB_VERSION_NLINKBIT;
+	return true;
 }
 
-static inline unsigned xfs_sb_version_toold(unsigned v)
+static inline bool xfs_sb_good_version(struct xfs_sb *sbp)
 {
-	if (v & (XFS_SB_VERSION_QUOTABIT | XFS_SB_VERSION_ALIGNBIT))
-		return 0;
-	if (v & XFS_SB_VERSION_NLINKBIT)
-		return XFS_SB_VERSION_3;
-	if (v & XFS_SB_VERSION_ATTRBIT)
-		return XFS_SB_VERSION_2;
-	return XFS_SB_VERSION_1;
-}
-
-static inline int xfs_sb_version_hasattr(xfs_sb_t *sbp)
-{
-	return sbp->sb_versionnum == XFS_SB_VERSION_2 ||
-		sbp->sb_versionnum == XFS_SB_VERSION_3 ||
-		(XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4 &&
-		 (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT));
+	if (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5)
+		return true;
+	if (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4)
+		return xfs_sb_good_v4_features(sbp);
+	return false;
 }
 
-static inline void xfs_sb_version_addattr(xfs_sb_t *sbp)
+/*
+ * 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 bool xfs_sb_has_mismatched_features2(struct xfs_sb *sbp)
 {
-	if (sbp->sb_versionnum == XFS_SB_VERSION_1)
-		sbp->sb_versionnum = XFS_SB_VERSION_2;
-	else if (XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4)
-		sbp->sb_versionnum |= XFS_SB_VERSION_ATTRBIT;
-	else
-		sbp->sb_versionnum = XFS_SB_VERSION_4 | XFS_SB_VERSION_ATTRBIT;
+	return sbp->sb_bad_features2 != sbp->sb_features2;
 }
 
-static inline int xfs_sb_version_hasnlink(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasattr(struct xfs_sb *sbp)
 {
-	return sbp->sb_versionnum == XFS_SB_VERSION_3 ||
-		 (XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4 &&
-		  (sbp->sb_versionnum & XFS_SB_VERSION_NLINKBIT));
+	return (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT);
 }
 
-static inline void xfs_sb_version_addnlink(xfs_sb_t *sbp)
+static inline void xfs_sb_version_addattr(struct xfs_sb *sbp)
 {
-	if (sbp->sb_versionnum <= XFS_SB_VERSION_2)
-		sbp->sb_versionnum = XFS_SB_VERSION_3;
-	else
-		sbp->sb_versionnum |= XFS_SB_VERSION_NLINKBIT;
+	sbp->sb_versionnum |= XFS_SB_VERSION_ATTRBIT;
 }
 
-static inline int xfs_sb_version_hasquota(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasquota(struct xfs_sb *sbp)
 {
-	return XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT);
+	return (sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT);
 }
 
-static inline void xfs_sb_version_addquota(xfs_sb_t *sbp)
+static inline void xfs_sb_version_addquota(struct xfs_sb *sbp)
 {
-	if (XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4)
-		sbp->sb_versionnum |= XFS_SB_VERSION_QUOTABIT;
-	else
-		sbp->sb_versionnum = xfs_sb_version_tonew(sbp->sb_versionnum) |
-					XFS_SB_VERSION_QUOTABIT;
+	sbp->sb_versionnum |= XFS_SB_VERSION_QUOTABIT;
 }
 
-static inline int xfs_sb_version_hasalign(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasalign(struct xfs_sb *sbp)
 {
-	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
-	       (XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4 &&
+	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 ||
 		(sbp->sb_versionnum & XFS_SB_VERSION_ALIGNBIT));
 }
 
-static inline int xfs_sb_version_hasdalign(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasdalign(struct xfs_sb *sbp)
 {
-	return XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT);
+	return (sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT);
 }
 
-static inline int xfs_sb_version_hasshared(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_haslogv2(struct xfs_sb *sbp)
 {
-	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_SHAREDBIT);
+	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 ||
+	       (sbp->sb_versionnum & XFS_SB_VERSION_LOGV2BIT);
 }
 
-static inline int xfs_sb_version_hasdirv2(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasextflgbit(struct xfs_sb *sbp)
 {
-	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
-	       (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_DIRV2BIT));
+	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 ||
+	       (sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT);
 }
 
-static inline int xfs_sb_version_haslogv2(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hassector(struct xfs_sb *sbp)
 {
-	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
-	       (XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_LOGV2BIT));
+	return (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT);
 }
 
-static inline int xfs_sb_version_hasextflgbit(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasasciici(struct xfs_sb *sbp)
 {
-	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
-	       (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT));
+	return (sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT);
 }
 
-static inline int xfs_sb_version_hassector(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasmorebits(struct xfs_sb *sbp)
 {
-	return XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT);
-}
-
-static inline int xfs_sb_version_hasasciici(xfs_sb_t *sbp)
-{
-	return XFS_SB_VERSION_NUM(sbp) >= XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT);
-}
-
-static inline int xfs_sb_version_hasmorebits(xfs_sb_t *sbp)
-{
-	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
-	       (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4 &&
-		(sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT));
+	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 ||
+	       (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT);
 }
 
 /*
  * sb_features2 bit version macros.
- *
- * For example, for a bit defined as XFS_SB_VERSION2_FUNBIT, has a macro:
- *
- * SB_VERSION_HASFUNBIT(xfs_sb_t *sbp)
- *	((xfs_sb_version_hasmorebits(sbp) &&
- *	 ((sbp)->sb_features2 & XFS_SB_VERSION2_FUNBIT)
  */
-
-static inline int xfs_sb_version_haslazysbcount(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_haslazysbcount(struct xfs_sb *sbp)
 {
 	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
 	       (xfs_sb_version_hasmorebits(sbp) &&
 		(sbp->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT));
 }
 
-static inline int xfs_sb_version_hasattr2(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasattr2(struct xfs_sb *sbp)
 {
 	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
 	       (xfs_sb_version_hasmorebits(sbp) &&
 		(sbp->sb_features2 & XFS_SB_VERSION2_ATTR2BIT));
 }
 
-static inline void xfs_sb_version_addattr2(xfs_sb_t *sbp)
+static inline void xfs_sb_version_addattr2(struct xfs_sb *sbp)
 {
 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
 	sbp->sb_features2 |= XFS_SB_VERSION2_ATTR2BIT;
+	sbp->sb_bad_features2 |= XFS_SB_VERSION2_ATTR2BIT;
 }
 
-static inline void xfs_sb_version_removeattr2(xfs_sb_t *sbp)
+static inline void xfs_sb_version_removeattr2(struct xfs_sb *sbp)
 {
 	sbp->sb_features2 &= ~XFS_SB_VERSION2_ATTR2BIT;
+	sbp->sb_bad_features2 &= ~XFS_SB_VERSION2_ATTR2BIT;
 	if (!sbp->sb_features2)
 		sbp->sb_versionnum &= ~XFS_SB_VERSION_MOREBITSBIT;
 }
 
-static inline int xfs_sb_version_hasprojid32bit(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasprojid32bit(struct xfs_sb *sbp)
 {
 	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
 	       (xfs_sb_version_hasmorebits(sbp) &&
 		(sbp->sb_features2 & XFS_SB_VERSION2_PROJID32BIT));
 }
 
-static inline void xfs_sb_version_addprojid32bit(xfs_sb_t *sbp)
+static inline void xfs_sb_version_addprojid32bit(struct xfs_sb *sbp)
 {
 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
 	sbp->sb_features2 |= XFS_SB_VERSION2_PROJID32BIT;
@@ -625,12 +534,12 @@ xfs_sb_has_incompat_log_feature(
 /*
  * V5 superblock specific feature checks
  */
-static inline int xfs_sb_version_hascrc(xfs_sb_t *sbp)
+static inline int xfs_sb_version_hascrc(struct xfs_sb *sbp)
 {
 	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
 }
 
-static inline int xfs_sb_version_has_pquotino(xfs_sb_t *sbp)
+static inline int xfs_sb_version_has_pquotino(struct xfs_sb *sbp)
 {
 	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
 }