xfs: define the zoned on-disk format

Zone file systems reuse the basic RT group enabled XFS file system
structure to support a mode where each RT group is always written from
start to end and then reset for reuse (after moving out any remaining
data).  There are few minor but important changes, which are indicated
by a new incompat flag:

1) there are no bitmap and summary inodes, thus the
   /rtgroups/{rgno}.{bitmap,summary} metadir files do not exist and the
   sb_rbmblocks superblock field must be cleared to zero.

2) there is a new superblock field that specifies the start of an
   internal RT section.  This allows supporting SMR HDDs that have random
   writable space at the beginning which is used for the XFS data device
   (which really is the metadata device for this configuration), directly
   followed by a RT device on the same block device.  While something
   similar could be achieved using dm-linear just having a single device
   directly consumed by XFS makes handling the file systems a lot easier.

3) Another superblock field that tracks the amount of reserved space (or
   overprovisioning) that is never used for user capacity, but allows GC
   to run more smoothly.

4) an overlay of the cowextsize field for the rtrmap inode so that we
   can persistently track the total amount of rtblocks currently used in
   a RT group.  There is no data structure other than the rmap that
   tracks used space in an RT group, and this counter is used to decide
   when a RT group has been entirely emptied, and to select one that
   is relatively empty if garbage collection needs to be performed.
   While this counter could be tracked entirely in memory and rebuilt
   from the rmap at mount time, that would lead to very long mount times
   with the large number of RT groups implied by the number of hardware
   zones especially on SMR hard drives with 256MB zone sizes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

fs/xfs/libxfs/xfs_format.h

@@ -178,9 +178,10 @@ typedef struct xfs_sb {
 
 	xfs_rgnumber_t	sb_rgcount;	/* number of realtime groups */
 	xfs_rtxlen_t	sb_rgextents;	/* size of a realtime group in rtx */
-
 	uint8_t		sb_rgblklog;    /* rt group number shift */
 	uint8_t		sb_pad[7];	/* zeroes */
+	xfs_rfsblock_t	sb_rtstart;	/* start of internal RT section (FSB) */
+	xfs_filblks_t	sb_rtreserved;	/* reserved (zoned) RT blocks */
 
 	/* must be padded to 64 bit alignment */
 } xfs_sb_t;
@@ -270,9 +271,10 @@ struct xfs_dsb {
 	__be64		sb_metadirino;	/* metadata directory tree root */
 	__be32		sb_rgcount;	/* # of realtime groups */
 	__be32		sb_rgextents;	/* size of rtgroup in rtx */
-
 	__u8		sb_rgblklog;    /* rt group number shift */
 	__u8		sb_pad[7];	/* zeroes */
+	__be64		sb_rtstart;	/* start of internal RT section (FSB) */
+	__be64		sb_rtreserved;	/* reserved (zoned) RT blocks */
 
 	/*
 	 * The size of this structure must be padded to 64 bit alignment.
@@ -395,6 +397,8 @@ xfs_sb_has_ro_compat_feature(
 #define XFS_SB_FEAT_INCOMPAT_EXCHRANGE	(1 << 6)  /* exchangerange supported */
 #define XFS_SB_FEAT_INCOMPAT_PARENT	(1 << 7)  /* parent pointers */
 #define XFS_SB_FEAT_INCOMPAT_METADIR	(1 << 8)  /* metadata dir tree */
+#define XFS_SB_FEAT_INCOMPAT_ZONED	(1 << 9)  /* zoned RT allocator */
+
 #define XFS_SB_FEAT_INCOMPAT_ALL \
 		(XFS_SB_FEAT_INCOMPAT_FTYPE | \
 		 XFS_SB_FEAT_INCOMPAT_SPINODES | \
@@ -952,7 +956,12 @@ struct xfs_dinode {
 	__be64		di_changecount;	/* number of attribute changes */
 	__be64		di_lsn;		/* flush sequence */
 	__be64		di_flags2;	/* more random flags */
-	__be32		di_cowextsize;	/* basic cow extent size for file */
+	union {
+		/* basic cow extent size for (regular) file */
+		__be32		di_cowextsize;
+		/* used blocks in RTG for (zoned) rtrmap inode */
+		__be32		di_used_blocks;
+	};
 	__u8		di_pad2[12];	/* more padding for future expansion */
 
 	/* fields only written to during inode creation */

fs/xfs/libxfs/xfs_inode_buf.c

@@ -252,7 +252,10 @@ xfs_inode_from_disk(
 					   be64_to_cpu(from->di_changecount));
 		ip->i_crtime = xfs_inode_from_disk_ts(from, from->di_crtime);
 		ip->i_diflags2 = be64_to_cpu(from->di_flags2);
+		/* also covers the di_used_blocks union arm: */
 		ip->i_cowextsize = be32_to_cpu(from->di_cowextsize);
+		BUILD_BUG_ON(sizeof(from->di_cowextsize) !=
+			     sizeof(from->di_used_blocks));
 	}
 
 	error = xfs_iformat_data_fork(ip, from);
@@ -349,6 +352,7 @@ xfs_inode_to_disk(
 		to->di_changecount = cpu_to_be64(inode_peek_iversion(inode));
 		to->di_crtime = xfs_inode_to_disk_ts(ip, ip->i_crtime);
 		to->di_flags2 = cpu_to_be64(ip->i_diflags2);
+		/* also covers the di_used_blocks union arm: */
 		to->di_cowextsize = cpu_to_be32(ip->i_cowextsize);
 		to->di_ino = cpu_to_be64(ip->i_ino);
 		to->di_lsn = cpu_to_be64(lsn);
@@ -752,11 +756,18 @@ xfs_dinode_verify(
 	    !xfs_has_rtreflink(mp))
 		return __this_address;
 
-	/* COW extent size hint validation */
+	if (xfs_has_zoned(mp) &&
-	fa = xfs_inode_validate_cowextsize(mp, be32_to_cpu(dip->di_cowextsize),
+	    dip->di_metatype == cpu_to_be16(XFS_METAFILE_RTRMAP)) {
-			mode, flags, flags2);
+		if (be32_to_cpu(dip->di_used_blocks) > mp->m_sb.sb_rgextents)
-	if (fa)
+			return __this_address;
-		return fa;
+	} else {
+		/* COW extent size hint validation */
+		fa = xfs_inode_validate_cowextsize(mp,
+				be32_to_cpu(dip->di_cowextsize),
+				mode, flags, flags2);
+		if (fa)
+			return fa;
+	}
 
 	/* bigtime iflag can only happen on bigtime filesystems */
 	if (xfs_dinode_has_bigtime(dip) &&

fs/xfs/libxfs/xfs_inode_util.c

@@ -322,6 +322,7 @@ xfs_inode_init(
 
 	if (xfs_has_v3inodes(mp)) {
 		inode_set_iversion(inode, 1);
+		/* also covers the di_used_blocks union arm: */
 		ip->i_cowextsize = 0;
 		times |= XFS_ICHGTIME_CREATE;
 	}

fs/xfs/libxfs/xfs_log_format.h

@@ -475,7 +475,12 @@ struct xfs_log_dinode {
 	xfs_lsn_t	di_lsn;
 
 	uint64_t	di_flags2;	/* more random flags */
-	uint32_t	di_cowextsize;	/* basic cow extent size for file */
+	union {
+		/* basic cow extent size for (regular) file */
+		uint32_t		di_cowextsize;
+		/* used blocks in RTG for (zoned) rtrmap inode */
+		uint32_t		di_used_blocks;
+	};
 	uint8_t		di_pad2[12];	/* more padding for future expansion */
 
 	/* fields only written to during inode creation */

fs/xfs/libxfs/xfs_ondisk.h

@@ -233,8 +233,8 @@ xfs_check_ondisk_structs(void)
 			16299260424LL);
 
 	/* superblock field checks we got from xfs/122 */
-	XFS_CHECK_STRUCT_SIZE(struct xfs_dsb,		288);
+	XFS_CHECK_STRUCT_SIZE(struct xfs_dsb,		304);
-	XFS_CHECK_STRUCT_SIZE(struct xfs_sb,		288);
+	XFS_CHECK_STRUCT_SIZE(struct xfs_sb,		304);
 	XFS_CHECK_SB_OFFSET(sb_magicnum,		0);
 	XFS_CHECK_SB_OFFSET(sb_blocksize,		4);
 	XFS_CHECK_SB_OFFSET(sb_dblocks,			8);
@@ -295,6 +295,8 @@ xfs_check_ondisk_structs(void)
 	XFS_CHECK_SB_OFFSET(sb_rgextents,		276);
 	XFS_CHECK_SB_OFFSET(sb_rgblklog,		280);
 	XFS_CHECK_SB_OFFSET(sb_pad,			281);
+	XFS_CHECK_SB_OFFSET(sb_rtstart,			288);
+	XFS_CHECK_SB_OFFSET(sb_rtreserved,		296);
 }
 
 #endif /* __XFS_ONDISK_H */

fs/xfs/libxfs/xfs_rtbitmap.c

@@ -1123,6 +1123,7 @@ xfs_rtfree_blocks(
 	xfs_extlen_t		mod;
 	int			error;
 
+	ASSERT(!xfs_has_zoned(mp));
 	ASSERT(rtlen <= XFS_MAX_BMBT_EXTLEN);
 
 	mod = xfs_blen_to_rtxoff(mp, rtlen);
@@ -1174,6 +1175,9 @@ xfs_rtalloc_query_range(
 
 	end = min(end, rtg->rtg_extents - 1);
 
+	if (xfs_has_zoned(mp))
+		return -EINVAL;
+
 	/* Iterate the bitmap, looking for discrepancies. */
 	while (start <= end) {
 		struct xfs_rtalloc_rec	rec;
@@ -1268,6 +1272,8 @@ xfs_rtbitmap_blockcount_len(
 	struct xfs_mount	*mp,
 	xfs_rtbxlen_t		rtextents)
 {
+	if (xfs_has_zoned(mp))
+		return 0;
 	return howmany_64(rtextents, xfs_rtbitmap_rtx_per_rbmblock(mp));
 }
 
@@ -1308,6 +1314,11 @@ xfs_rtsummary_blockcount(
 	xfs_rtbxlen_t		rextents = xfs_rtbitmap_bitcount(mp);
 	unsigned long long	rsumwords;
 
+	if (xfs_has_zoned(mp)) {
+		*rsumlevels = 0;
+		return 0;
+	}
+
 	*rsumlevels = xfs_compute_rextslog(rextents) + 1;
 	rsumwords = xfs_rtbitmap_blockcount_len(mp, rextents) * (*rsumlevels);
 	return howmany_64(rsumwords, mp->m_blockwsize);

fs/xfs/libxfs/xfs_rtgroup.c

@@ -194,15 +194,17 @@ xfs_rtgroup_lock(
 	ASSERT(!(rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED) ||
 	       !(rtglock_flags & XFS_RTGLOCK_BITMAP));
 
-	if (rtglock_flags & XFS_RTGLOCK_BITMAP) {
+	if (!xfs_has_zoned(rtg_mount(rtg))) {
-		/*
+		if (rtglock_flags & XFS_RTGLOCK_BITMAP) {
-		 * Lock both realtime free space metadata inodes for a freespace
+			/*
-		 * update.
+			 * Lock both realtime free space metadata inodes for a
-		 */
+			 * freespace update.
-		xfs_ilock(rtg_bitmap(rtg), XFS_ILOCK_EXCL);
+			 */
-		xfs_ilock(rtg_summary(rtg), XFS_ILOCK_EXCL);
+			xfs_ilock(rtg_bitmap(rtg), XFS_ILOCK_EXCL);
-	} else if (rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED) {
+			xfs_ilock(rtg_summary(rtg), XFS_ILOCK_EXCL);
-		xfs_ilock(rtg_bitmap(rtg), XFS_ILOCK_SHARED);
+		} else if (rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED) {
+			xfs_ilock(rtg_bitmap(rtg), XFS_ILOCK_SHARED);
+		}
 	}
 
 	if ((rtglock_flags & XFS_RTGLOCK_RMAP) && rtg_rmap(rtg))
@@ -228,11 +230,13 @@ xfs_rtgroup_unlock(
 	if ((rtglock_flags & XFS_RTGLOCK_RMAP) && rtg_rmap(rtg))
 		xfs_iunlock(rtg_rmap(rtg), XFS_ILOCK_EXCL);
 
-	if (rtglock_flags & XFS_RTGLOCK_BITMAP) {
+	if (!xfs_has_zoned(rtg_mount(rtg))) {
-		xfs_iunlock(rtg_summary(rtg), XFS_ILOCK_EXCL);
+		if (rtglock_flags & XFS_RTGLOCK_BITMAP) {
-		xfs_iunlock(rtg_bitmap(rtg), XFS_ILOCK_EXCL);
+			xfs_iunlock(rtg_summary(rtg), XFS_ILOCK_EXCL);
-	} else if (rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED) {
+			xfs_iunlock(rtg_bitmap(rtg), XFS_ILOCK_EXCL);
-		xfs_iunlock(rtg_bitmap(rtg), XFS_ILOCK_SHARED);
+		} else if (rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED) {
+			xfs_iunlock(rtg_bitmap(rtg), XFS_ILOCK_SHARED);
+		}
 	}
 }
 
@@ -249,7 +253,8 @@ xfs_rtgroup_trans_join(
 	ASSERT(!(rtglock_flags & ~XFS_RTGLOCK_ALL_FLAGS));
 	ASSERT(!(rtglock_flags & XFS_RTGLOCK_BITMAP_SHARED));
 
-	if (rtglock_flags & XFS_RTGLOCK_BITMAP) {
+	if (!xfs_has_zoned(rtg_mount(rtg)) &&
+	    (rtglock_flags & XFS_RTGLOCK_BITMAP)) {
 		xfs_trans_ijoin(tp, rtg_bitmap(rtg), XFS_ILOCK_EXCL);
 		xfs_trans_ijoin(tp, rtg_summary(rtg), XFS_ILOCK_EXCL);
 	}
@@ -354,6 +359,7 @@ static const struct xfs_rtginode_ops xfs_rtginode_ops[XFS_RTGI_MAX] = {
 		.sick		= XFS_SICK_RG_BITMAP,
 		.fmt_mask	= (1U << XFS_DINODE_FMT_EXTENTS) |
 				  (1U << XFS_DINODE_FMT_BTREE),
+		.enabled	= xfs_has_nonzoned,
 		.create		= xfs_rtbitmap_create,
 	},
 	[XFS_RTGI_SUMMARY] = {
@@ -362,6 +368,7 @@ static const struct xfs_rtginode_ops xfs_rtginode_ops[XFS_RTGI_MAX] = {
 		.sick		= XFS_SICK_RG_SUMMARY,
 		.fmt_mask	= (1U << XFS_DINODE_FMT_EXTENTS) |
 				  (1U << XFS_DINODE_FMT_BTREE),
+		.enabled	= xfs_has_nonzoned,
 		.create		= xfs_rtsummary_create,
 	},
 	[XFS_RTGI_RMAP] = {

fs/xfs/libxfs/xfs_sb.c

@@ -30,6 +30,7 @@
 #include "xfs_rtgroup.h"
 #include "xfs_rtrmap_btree.h"
 #include "xfs_rtrefcount_btree.h"
+#include "xfs_rtbitmap.h"
 
 /*
  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
@@ -185,6 +186,8 @@ xfs_sb_version_to_features(
 		features |= XFS_FEAT_PARENT;
 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR)
 		features |= XFS_FEAT_METADIR;
+	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_ZONED)
+		features |= XFS_FEAT_ZONED;
 
 	return features;
 }
@@ -266,6 +269,9 @@ static uint64_t
 xfs_expected_rbmblocks(
 	struct xfs_sb		*sbp)
 {
+	if (xfs_sb_is_v5(sbp) &&
+	    (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_ZONED))
+		return 0;
 	return howmany_64(xfs_extents_per_rbm(sbp),
 			  NBBY * xfs_rtbmblock_size(sbp));
 }
@@ -275,9 +281,15 @@ bool
 xfs_validate_rt_geometry(
 	struct xfs_sb		*sbp)
 {
-	if (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE ||
+	if (xfs_sb_is_v5(sbp) &&
-	    sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)
+	    (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_ZONED)) {
-		return false;
+		if (sbp->sb_rextsize != 1)
+			return false;
+	} else {
+		if (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE ||
+		    sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)
+			return false;
+	}
 
 	if (sbp->sb_rblocks == 0) {
 		if (sbp->sb_rextents != 0 || sbp->sb_rbmblocks != 0 ||
@@ -435,6 +447,34 @@ xfs_validate_sb_rtgroups(
 	return 0;
 }
 
+static int
+xfs_validate_sb_zoned(
+	struct xfs_mount	*mp,
+	struct xfs_sb		*sbp)
+{
+	if (sbp->sb_frextents != 0) {
+		xfs_warn(mp,
+"sb_frextents must be zero for zoned file systems.");
+		return -EINVAL;
+	}
+
+	if (sbp->sb_rtstart && sbp->sb_rtstart < sbp->sb_dblocks) {
+		xfs_warn(mp,
+"sb_rtstart (%lld) overlaps sb_dblocks (%lld).",
+			sbp->sb_rtstart, sbp->sb_dblocks);
+		return -EINVAL;
+	}
+
+	if (sbp->sb_rtreserved && sbp->sb_rtreserved >= sbp->sb_rblocks) {
+		xfs_warn(mp,
+"sb_rtreserved (%lld) larger than sb_rblocks (%lld).",
+			sbp->sb_rtreserved, sbp->sb_rblocks);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /* Check the validity of the SB. */
 STATIC int
 xfs_validate_sb_common(
@@ -523,6 +563,11 @@ xfs_validate_sb_common(
 			if (error)
 				return error;
 		}
+		if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_ZONED) {
+			error = xfs_validate_sb_zoned(mp, sbp);
+			if (error)
+				return error;
+		}
 	} else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
 				XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
 			xfs_notice(mp,
@@ -835,6 +880,14 @@ __xfs_sb_from_disk(
 		to->sb_rgcount = 1;
 		to->sb_rgextents = 0;
 	}
+
+	if (to->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_ZONED) {
+		to->sb_rtstart = be64_to_cpu(from->sb_rtstart);
+		to->sb_rtreserved = be64_to_cpu(from->sb_rtreserved);
+	} else {
+		to->sb_rtstart = 0;
+		to->sb_rtreserved = 0;
+	}
 }
 
 void
@@ -1001,6 +1054,11 @@ xfs_sb_to_disk(
 		to->sb_rbmino = cpu_to_be64(0);
 		to->sb_rsumino = cpu_to_be64(0);
 	}
+
+	if (from->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_ZONED) {
+		to->sb_rtstart = cpu_to_be64(from->sb_rtstart);
+		to->sb_rtreserved = cpu_to_be64(from->sb_rtreserved);
+	}
 }
 
 /*

fs/xfs/scrub/agheader.c

@@ -69,6 +69,8 @@ STATIC size_t
 xchk_superblock_ondisk_size(
 	struct xfs_mount	*mp)
 {
+	if (xfs_has_zoned(mp))
+		return offsetofend(struct xfs_dsb, sb_rtreserved);
 	if (xfs_has_metadir(mp))
 		return offsetofend(struct xfs_dsb, sb_pad);
 	if (xfs_has_metauuid(mp))

fs/xfs/scrub/inode.c

@@ -273,6 +273,13 @@ xchk_inode_cowextsize(
 	xfs_failaddr_t		fa;
 	uint32_t		value = be32_to_cpu(dip->di_cowextsize);
 
+	/*
+	 * The used block counter for rtrmap is checked and repaired elsewhere.
+	 */
+	if (xfs_has_zoned(sc->mp) &&
+	    dip->di_metatype == cpu_to_be16(XFS_METAFILE_RTRMAP))
+		return;
+
 	fa = xfs_inode_validate_cowextsize(sc->mp, value, mode, flags, flags2);
 	if (fa)
 		xchk_ino_set_corrupt(sc, ino);

fs/xfs/scrub/inode_repair.c

@@ -710,7 +710,9 @@ xrep_dinode_extsize_hints(
 					      XFS_DIFLAG_EXTSZINHERIT);
 	}
 
-	if (dip->di_version < 3)
+	if (dip->di_version < 3 ||
+	    (xfs_has_zoned(sc->mp) &&
+	     dip->di_metatype == cpu_to_be16(XFS_METAFILE_RTRMAP)))
 		return;
 
 	fa = xfs_inode_validate_cowextsize(mp, be32_to_cpu(dip->di_cowextsize),

fs/xfs/scrub/scrub.c

@@ -399,12 +399,14 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
 	},
 	[XFS_SCRUB_TYPE_RTBITMAP] = {	/* realtime bitmap */
 		.type	= ST_RTGROUP,
+		.has	= xfs_has_nonzoned,
 		.setup	= xchk_setup_rtbitmap,
 		.scrub	= xchk_rtbitmap,
 		.repair	= xrep_rtbitmap,
 	},
 	[XFS_SCRUB_TYPE_RTSUM] = {	/* realtime summary */
 		.type	= ST_RTGROUP,
+		.has	= xfs_has_nonzoned,
 		.setup	= xchk_setup_rtsummary,
 		.scrub	= xchk_rtsummary,
 		.repair	= xrep_rtsummary,

fs/xfs/xfs_fsmap.c

@@ -1138,7 +1138,11 @@ xfs_getfsmap(
 		handlers[1].fn = xfs_getfsmap_logdev;
 	}
 #ifdef CONFIG_XFS_RT
-	if (mp->m_rtdev_targp) {
+	/*
+	 * For zoned file systems there is no rtbitmap, so only support fsmap
+	 * if the callers is privileged enough to use the full rmap version.
+	 */
+	if (mp->m_rtdev_targp && (use_rmap || !xfs_has_zoned(mp))) {
 		handlers[2].nr_sectors = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
 		handlers[2].dev = new_encode_dev(mp->m_rtdev_targp->bt_dev);
 		if (use_rmap)

fs/xfs/xfs_inode.c

@@ -3074,5 +3074,6 @@ bool
 xfs_is_always_cow_inode(
 	const struct xfs_inode	*ip)
 {
-	return ip->i_mount->m_always_cow && xfs_has_reflink(ip->i_mount);
+	return xfs_is_zoned_inode(ip) ||
+		(ip->i_mount->m_always_cow && xfs_has_reflink(ip->i_mount));
 }

fs/xfs/xfs_inode.h

@@ -59,8 +59,13 @@ typedef struct xfs_inode {
 	xfs_rfsblock_t		i_nblocks;	/* # of direct & btree blocks */
 	prid_t			i_projid;	/* owner's project id */
 	xfs_extlen_t		i_extsize;	/* basic/minimum extent size */
-	/* cowextsize is only used for v3 inodes, flushiter for v1/2 */
+	/*
+	 * i_used_blocks is used for zoned rtrmap inodes,
+	 * i_cowextsize is used for other v3 inodes,
+	 * i_flushiter for v1/2 inodes
+	 */
 	union {
+		uint32_t	i_used_blocks;	/* used blocks in RTG */
 		xfs_extlen_t	i_cowextsize;	/* basic cow extent size */
 		uint16_t	i_flushiter;	/* incremented on flush */
 	};
@@ -299,6 +304,11 @@ static inline bool xfs_is_internal_inode(const struct xfs_inode *ip)
 	       xfs_is_quota_inode(&mp->m_sb, ip->i_ino);
 }
 
+static inline bool xfs_is_zoned_inode(const struct xfs_inode *ip)
+{
+	return xfs_has_zoned(ip->i_mount) && XFS_IS_REALTIME_INODE(ip);
+}
+
 bool xfs_is_always_cow_inode(const struct xfs_inode *ip);
 
 static inline bool xfs_is_cow_inode(const struct xfs_inode *ip)

fs/xfs/xfs_inode_item.c

@@ -596,6 +596,7 @@ xfs_inode_to_log_dinode(
 		to->di_changecount = inode_peek_iversion(inode);
 		to->di_crtime = xfs_inode_to_log_dinode_ts(ip, ip->i_crtime);
 		to->di_flags2 = ip->i_diflags2;
+		/* also covers the di_used_blocks union arm: */
 		to->di_cowextsize = ip->i_cowextsize;
 		to->di_ino = ip->i_ino;
 		to->di_lsn = lsn;

fs/xfs/xfs_inode_item_recover.c

@@ -203,6 +203,7 @@ xfs_log_dinode_to_disk(
 		to->di_crtime = xfs_log_dinode_to_disk_ts(from,
 							  from->di_crtime);
 		to->di_flags2 = cpu_to_be64(from->di_flags2);
+		/* also covers the di_used_blocks union arm: */
 		to->di_cowextsize = cpu_to_be32(from->di_cowextsize);
 		to->di_ino = cpu_to_be64(from->di_ino);
 		to->di_lsn = cpu_to_be64(lsn);

fs/xfs/xfs_iomap.c

@@ -1214,6 +1214,7 @@ retry:
 
 	fdblocks = indlen;
 	if (XFS_IS_REALTIME_INODE(ip)) {
+		ASSERT(!xfs_is_zoned_inode(ip));
 		error = xfs_dec_frextents(mp, xfs_blen_to_rtbxlen(mp, alen));
 		if (error)
 			goto out_unreserve_quota;

fs/xfs/xfs_message.c

@@ -173,6 +173,10 @@ xfs_warn_experimental(
 			.opstate	= XFS_OPSTATE_WARNED_METADIR,
 			.name		= "metadata directory tree",
 		},
+		[XFS_EXPERIMENTAL_ZONED] = {
+			.opstate	= XFS_OPSTATE_WARNED_ZONED,
+			.name		= "zoned RT device",
+		},
 	};
 	ASSERT(feat >= 0 && feat < XFS_EXPERIMENTAL_MAX);
 	BUILD_BUG_ON(ARRAY_SIZE(features) != XFS_EXPERIMENTAL_MAX);

fs/xfs/xfs_message.h

@@ -99,6 +99,7 @@ enum xfs_experimental_feat {
 	XFS_EXPERIMENTAL_EXCHRANGE,
 	XFS_EXPERIMENTAL_PPTR,
 	XFS_EXPERIMENTAL_METADIR,
+	XFS_EXPERIMENTAL_ZONED,
 
 	XFS_EXPERIMENTAL_MAX,
 };

fs/xfs/xfs_mount.h

@@ -352,6 +352,7 @@ typedef struct xfs_mount {
 #define XFS_FEAT_NREXT64	(1ULL << 26)	/* large extent counters */
 #define XFS_FEAT_EXCHANGE_RANGE	(1ULL << 27)	/* exchange range */
 #define XFS_FEAT_METADIR	(1ULL << 28)	/* metadata directory tree */
+#define XFS_FEAT_ZONED		(1ULL << 29)	/* zoned RT device */
 
 /* Mount features */
 #define XFS_FEAT_NOATTR2	(1ULL << 48)	/* disable attr2 creation */
@@ -408,6 +409,7 @@ __XFS_HAS_FEAT(needsrepair, NEEDSREPAIR)
 __XFS_HAS_FEAT(large_extent_counts, NREXT64)
 __XFS_HAS_FEAT(exchange_range, EXCHANGE_RANGE)
 __XFS_HAS_FEAT(metadir, METADIR)
+__XFS_HAS_FEAT(zoned, ZONED)
 
 static inline bool xfs_has_rtgroups(const struct xfs_mount *mp)
 {
@@ -418,7 +420,9 @@ static inline bool xfs_has_rtgroups(const struct xfs_mount *mp)
 static inline bool xfs_has_rtsb(const struct xfs_mount *mp)
 {
 	/* all rtgroups filesystems with an rt section have an rtsb */
-	return xfs_has_rtgroups(mp) && xfs_has_realtime(mp);
+	return xfs_has_rtgroups(mp) &&
+		xfs_has_realtime(mp) &&
+		!xfs_has_zoned(mp);
 }
 
 static inline bool xfs_has_rtrmapbt(const struct xfs_mount *mp)
@@ -433,6 +437,11 @@ static inline bool xfs_has_rtreflink(const struct xfs_mount *mp)
 	       xfs_has_reflink(mp);
 }
 
+static inline bool xfs_has_nonzoned(const struct xfs_mount *mp)
+{
+	return !xfs_has_zoned(mp);
+}
+
 /*
  * Some features are always on for v5 file systems, allow the compiler to
  * eliminiate dead code when building without v4 support.
@@ -536,6 +545,8 @@ __XFS_HAS_FEAT(nouuid, NOUUID)
 #define XFS_OPSTATE_WARNED_METADIR	17
 /* Filesystem should use qflags to determine quotaon status */
 #define XFS_OPSTATE_RESUMING_QUOTAON	18
+/* Kernel has logged a warning about zoned RT device being used on this fs. */
+#define XFS_OPSTATE_WARNED_ZONED	19
 
 #define __XFS_IS_OPSTATE(name, NAME) \
 static inline bool xfs_is_ ## name (struct xfs_mount *mp) \

fs/xfs/xfs_rtalloc.c

@@ -2056,6 +2056,8 @@ xfs_bmap_rtalloc(
 		ap->datatype & XFS_ALLOC_INITIAL_USER_DATA;
 	int			error;
 
+	ASSERT(!xfs_has_zoned(ap->tp->t_mountp));
+
 retry:
 	error = xfs_rtallocate_align(ap, &ralen, &raminlen, &prod, &noalign);
 	if (error)

fs/xfs/xfs_super.c

@@ -1792,8 +1792,17 @@ xfs_fs_fill_super(
 		mp->m_features &= ~XFS_FEAT_DISCARD;
 	}
 
-	if (xfs_has_metadir(mp))
+	if (xfs_has_zoned(mp)) {
+		if (!xfs_has_metadir(mp)) {
+			xfs_alert(mp,
+		"metadir feature required for zoned realtime devices.");
+			error = -EINVAL;
+			goto out_filestream_unmount;
+		}
+		xfs_warn_experimental(mp, XFS_EXPERIMENTAL_ZONED);
+	} else if (xfs_has_metadir(mp)) {
 		xfs_warn_experimental(mp, XFS_EXPERIMENTAL_METADIR);
+	}
 
 	if (xfs_has_reflink(mp)) {
 		if (xfs_has_realtime(mp) &&