[PATCH 2/2] xfsprogs: Extend attr extent counter to 32-bits

[Chandan Rajendra <chandanrlinux@gmail.com>]

XFS has a per-inode xattr extent counter which is 16 bits wide. A workload
which
1. Creates 1,000,000 255-byte sized xattrs,
2. Deletes 50% of these xattrs in an alternating manner,
3. Tries to create 400,000 new 255-byte sized xattrs
causes the following message to be printed on the console,

XFS (loop0): xfs_iflush_int: detected corrupt incore inode 131, total extents = -19916, nblocks = 102937, ptr ffff9ce33b098c00
XFS (loop0): xfs_do_force_shutdown(0x8) called from line 3739 of file fs/xfs/xfs_inode.c. Return address = ffffffffa4a94173

This indicates that we overflowed the 16-bits wide xattr extent counter.

I have been informed that there are instances where a single file has
 > 100 million hardlinks. With parent pointers being stored in xattr,
we will overflow the 16-bits wide xattr extent counter when large
number of hardlinks are created.

Hence this commit extends xattr extent counter to 32-bits. It also
introduces an incompat flag to prevent older kernels from mounting
newer filesystems with 32-bit wide xattr extent counter.

Signed-off-by: Chandan Rajendra <chandanrlinux@gmail.com>
---
 db/bmap.c                |  4 ++--
 db/btdump.c              |  2 +-
 db/check.c               |  3 ++-
 db/field.c               |  2 --
 db/field.h               |  1 -
 db/frag.c                |  6 ++++--
 db/inode.c               | 10 ++++++----
 db/metadump.c            |  4 ++--
 libxfs/xfs_format.h      | 32 ++++++++++++++++++++++++--------
 libxfs/xfs_inode_buf.c   | 28 ++++++++++++++++++++--------
 libxfs/xfs_inode_fork.c  |  3 ++-
 libxfs/xfs_log_format.h  |  5 +++--
 libxfs/xfs_types.h       |  4 ++--
 logprint/log_misc.c      |  9 ++++++++-
 logprint/log_print_all.c |  9 ++++++++-
 mkfs/xfs_mkfs.c          |  1 +
 repair/attr_repair.c     |  2 +-
 repair/dinode.c          | 29 ++++++++++++++++++-----------
 18 files changed, 104 insertions(+), 50 deletions(-)

diff --git a/db/bmap.c b/db/bmap.c
index fdc70e95..2407a597 100644
--- a/db/bmap.c
+++ b/db/bmap.c
@@ -68,7 +68,7 @@ bmap(
 	ASSERT(fmt == XFS_DINODE_FMT_LOCAL || fmt == XFS_DINODE_FMT_EXTENTS ||
 		fmt == XFS_DINODE_FMT_BTREE);
 	if (fmt == XFS_DINODE_FMT_EXTENTS) {
-		nextents = XFS_DFORK_NEXTENTS(dip, whichfork);
+		nextents = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, whichfork);
 		xp = (xfs_bmbt_rec_t *)XFS_DFORK_PTR(dip, whichfork);
 		for (ep = xp; ep < &xp[nextents] && n < nex; ep++) {
 			if (!bmap_one_extent(ep, &curoffset, eoffset, &n, bep))
@@ -160,7 +160,7 @@ bmap_f(
 		dip = iocur_top->data;
 		if (be32_to_cpu(dip->di_nextents))
 			dfork = 1;
-		if (be16_to_cpu(dip->di_anextents))
+		if (XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_ATTR_FORK))
 			afork = 1;
 		pop_cur();
 	}
diff --git a/db/btdump.c b/db/btdump.c
index 920f595b..549fe5b3 100644
--- a/db/btdump.c
+++ b/db/btdump.c
@@ -166,7 +166,7 @@ dump_inode(
 
 	dip = iocur_top->data;
 	if (attrfork) {
-		if (!dip->di_anextents ||
+		if (!XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_ATTR_FORK) ||
 		    dip->di_aformat != XFS_DINODE_FMT_BTREE) {
 			dbprintf(_("attr fork not in btree format\n"));
 			return 0;
diff --git a/db/check.c b/db/check.c
index 3b713bdc..678557fa 100644
--- a/db/check.c
+++ b/db/check.c
@@ -2643,7 +2643,7 @@ process_exinode(
 	xfs_bmbt_rec_t		*rp;
 
 	rp = (xfs_bmbt_rec_t *)XFS_DFORK_PTR(dip, whichfork);
-	*nex = XFS_DFORK_NEXTENTS(dip, whichfork);
+	*nex = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, whichfork);
 	if (*nex < 0 || *nex > XFS_DFORK_SIZE(dip, mp, whichfork) /
 						sizeof(xfs_bmbt_rec_t)) {
 		if (!sflag || id->ilist)
@@ -2707,6 +2707,7 @@ process_inode(
 		"dev", "local", "extents", "btree", "uuid"
 	};
 
+	xino.i_mount = mp;
 	libxfs_inode_from_disk(&xino, dip);
 
 	ino = XFS_AGINO_TO_INO(mp, be32_to_cpu(agf->agf_seqno), agino);
diff --git a/db/field.c b/db/field.c
index aa0154d8..bbec8356 100644
--- a/db/field.c
+++ b/db/field.c
@@ -25,8 +25,6 @@
 #include "symlink.h"
 
 const ftattr_t	ftattrtab[] = {
-	{ FLDT_AEXTNUM, "aextnum", fp_num, "%d", SI(bitsz(xfs_aextnum_t)),
-	  FTARG_SIGNED, NULL, NULL },
 	{ FLDT_AGBLOCK, "agblock", fp_num, "%u", SI(bitsz(xfs_agblock_t)),
 	  FTARG_DONULL, fa_agblock, NULL },
 	{ FLDT_AGBLOCKNZ, "agblocknz", fp_num, "%u", SI(bitsz(xfs_agblock_t)),
diff --git a/db/field.h b/db/field.h
index 15065373..9e181d7a 100644
--- a/db/field.h
+++ b/db/field.h
@@ -5,7 +5,6 @@
  */
 
 typedef enum fldt	{
-	FLDT_AEXTNUM,
 	FLDT_AGBLOCK,
 	FLDT_AGBLOCKNZ,
 	FLDT_AGF,
diff --git a/db/frag.c b/db/frag.c
index 1cfc6c2c..16556a63 100644
--- a/db/frag.c
+++ b/db/frag.c
@@ -262,9 +262,11 @@ process_exinode(
 	int			whichfork)
 {
 	xfs_bmbt_rec_t		*rp;
+	int			nextents;
 
 	rp = (xfs_bmbt_rec_t *)XFS_DFORK_PTR(dip, whichfork);
-	process_bmbt_reclist(rp, XFS_DFORK_NEXTENTS(dip, whichfork), extmapp);
+	nextents = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, whichfork);
+	process_bmbt_reclist(rp, nextents, extmapp);
 }
 
 static void
@@ -275,7 +277,7 @@ process_fork(
 	extmap_t	*extmap;
 	int		nex;
 
-	nex = XFS_DFORK_NEXTENTS(dip, whichfork);
+	nex = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, whichfork);
 	if (!nex)
 		return;
 	extmap = extmap_alloc(nex);
diff --git a/db/inode.c b/db/inode.c
index 0cff9d63..802231c2 100644
--- a/db/inode.c
+++ b/db/inode.c
@@ -101,7 +101,7 @@ const field_t	inode_core_flds[] = {
 	{ "nblocks", FLDT_DRFSBNO, OI(COFF(nblocks)), C1, 0, TYP_NONE },
 	{ "extsize", FLDT_EXTLEN, OI(COFF(extsize)), C1, 0, TYP_NONE },
 	{ "nextents", FLDT_EXTNUM, OI(COFF(nextents)), C1, 0, TYP_NONE },
-	{ "naextents", FLDT_AEXTNUM, OI(COFF(anextents)), C1, 0, TYP_NONE },
+	{ "naextents_lo", FLDT_UINT16D, OI(COFF(anextents_lo)), C1, 0, TYP_NONE },
 	{ "forkoff", FLDT_UINT8D, OI(COFF(forkoff)), C1, 0, TYP_NONE },
 	{ "aformat", FLDT_DINODE_FMT, OI(COFF(aformat)), C1, 0, TYP_NONE },
 	{ "dmevmask", FLDT_UINT32X, OI(COFF(dmevmask)), C1, 0, TYP_NONE },
@@ -162,6 +162,7 @@ const field_t	inode_v3_flds[] = {
 	{ "lsn", FLDT_UINT64X, OI(COFF(lsn)), C1, 0, TYP_NONE },
 	{ "flags2", FLDT_UINT64X, OI(COFF(flags2)), C1, 0, TYP_NONE },
 	{ "cowextsize", FLDT_EXTLEN, OI(COFF(cowextsize)), C1, 0, TYP_NONE },
+	{ "naextents_hi", FLDT_UINT16D, OI(COFF(anextents_hi)), C1, 0, TYP_NONE },
 	{ "pad2", FLDT_UINT8X, OI(OFF(pad2)), CI(12), FLD_ARRAY|FLD_SKIPALL, TYP_NONE },
 	{ "crtime", FLDT_TIMESTAMP, OI(COFF(crtime)), C1, 0, TYP_NONE },
 	{ "inumber", FLDT_INO, OI(COFF(ino)), C1, 0, TYP_NONE },
@@ -271,7 +272,7 @@ inode_a_bmx_count(
 		return 0;
 	ASSERT((char *)XFS_DFORK_APTR(dip) - (char *)dip == byteize(startoff));
 	return dip->di_aformat == XFS_DINODE_FMT_EXTENTS ?
-		be16_to_cpu(dip->di_anextents) : 0;
+		XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_ATTR_FORK) : 0;
 }
 
 static int
@@ -325,6 +326,7 @@ inode_a_size(
 {
 	xfs_attr_shortform_t	*asf;
 	xfs_dinode_t		*dip;
+	int 			nextents;
 
 	ASSERT(startoff == 0);
 	ASSERT(idx == 0);
@@ -334,8 +336,8 @@ inode_a_size(
 		asf = (xfs_attr_shortform_t *)XFS_DFORK_APTR(dip);
 		return bitize(be16_to_cpu(asf->hdr.totsize));
 	case XFS_DINODE_FMT_EXTENTS:
-		return (int)be16_to_cpu(dip->di_anextents) *
-							bitsz(xfs_bmbt_rec_t);
+		nextents = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_ATTR_FORK);
+		return nextents * bitsz(xfs_bmbt_rec_t);
 	case XFS_DINODE_FMT_BTREE:
 		return bitize((int)XFS_DFORK_ASIZE(dip, mp));
 	default:
diff --git a/db/metadump.c b/db/metadump.c
index d542762e..182198eb 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -2282,7 +2282,7 @@ process_exinode(
 
 	whichfork = (itype == TYP_ATTR) ? XFS_ATTR_FORK : XFS_DATA_FORK;
 
-	nex = XFS_DFORK_NEXTENTS(dip, whichfork);
+	nex = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, whichfork);
 	used = nex * sizeof(xfs_bmbt_rec_t);
 	if (nex < 0 || used > XFS_DFORK_SIZE(dip, mp, whichfork)) {
 		if (show_warnings)
@@ -2335,7 +2335,7 @@ static int
 process_dev_inode(
 	xfs_dinode_t		*dip)
 {
-	if (XFS_DFORK_NEXTENTS(dip, XFS_DATA_FORK)) {
+	if (XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_DATA_FORK)) {
 		if (show_warnings)
 			print_warning("inode %llu has unexpected extents",
 				      (unsigned long long)cur_ino);
diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index e856e54c..61c3df6a 100644
--- a/libxfs/xfs_format.h
+++ b/libxfs/xfs_format.h
@@ -465,10 +465,13 @@ xfs_sb_has_ro_compat_feature(
 #define XFS_SB_FEAT_INCOMPAT_FTYPE	(1 << 0)	/* filetype in dirent */
 #define XFS_SB_FEAT_INCOMPAT_SPINODES	(1 << 1)	/* sparse inode chunks */
 #define XFS_SB_FEAT_INCOMPAT_META_UUID	(1 << 2)	/* metadata UUID */
-#define XFS_SB_FEAT_INCOMPAT_ALL \
+#define XFS_SB_FEAT_INCOMPAT_32BIT_AEXT_CNTR (1 << 3)
+#define XFS_SB_FEAT_INCOMPAT_ALL		\
 		(XFS_SB_FEAT_INCOMPAT_FTYPE|	\
 		 XFS_SB_FEAT_INCOMPAT_SPINODES|	\
-		 XFS_SB_FEAT_INCOMPAT_META_UUID)
+		 XFS_SB_FEAT_INCOMPAT_META_UUID | \
+		 XFS_SB_FEAT_INCOMPAT_32BIT_AEXT_CNTR)
+
 
 #define XFS_SB_FEAT_INCOMPAT_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_ALL
 static inline bool
@@ -866,7 +869,7 @@ typedef struct xfs_dinode {
 	__be64		di_nblocks;	/* # of direct & btree blocks used */
 	__be32		di_extsize;	/* basic/minimum extent size for file */
 	__be32		di_nextents;	/* number of extents in data fork */
-	__be16		di_anextents;	/* number of extents in attribute fork*/
+	__be16		di_anextents_lo;	/* number of extents in attribute fork*/
 	__u8		di_forkoff;	/* attr fork offs, <<3 for 64b align */
 	__s8		di_aformat;	/* format of attr fork's data */
 	__be32		di_dmevmask;	/* DMIG event mask */
@@ -883,7 +886,8 @@ typedef struct xfs_dinode {
 	__be64		di_lsn;		/* flush sequence */
 	__be64		di_flags2;	/* more random flags */
 	__be32		di_cowextsize;	/* basic cow extent size for file */
-	__u8		di_pad2[12];	/* more padding for future expansion */
+	__be16		di_anextents_hi;
+	__u8		di_pad2[10];	/* more padding for future expansion */
 
 	/* fields only written to during inode creation */
 	xfs_timestamp_t	di_crtime;	/* time created */
@@ -985,10 +989,22 @@ enum xfs_dinode_fmt {
 	((w) == XFS_DATA_FORK ? \
 		(dip)->di_format : \
 		(dip)->di_aformat)
-#define XFS_DFORK_NEXTENTS(dip,w) \
-	((w) == XFS_DATA_FORK ? \
-		be32_to_cpu((dip)->di_nextents) : \
-		be16_to_cpu((dip)->di_anextents))
+
+static inline int32_t XFS_DFORK_NEXTENTS(struct xfs_sb *sbp,
+					struct xfs_dinode *dip, int whichfork)
+{
+        int32_t anextents;
+
+        if (whichfork == XFS_DATA_FORK)
+                return be32_to_cpu((dip)->di_nextents);
+
+        anextents = be16_to_cpu((dip)->di_anextents_lo);
+        if (xfs_sb_version_hascrc(sbp))
+                anextents |=
+			((uint32_t)(be16_to_cpu((dip)->di_anextents_hi)) << 16);
+
+        return anextents;
+}
 
 /*
  * For block and character special files the 32bit dev_t is stored at the
diff --git a/libxfs/xfs_inode_buf.c b/libxfs/xfs_inode_buf.c
index 4c90e198..815cc944 100644
--- a/libxfs/xfs_inode_buf.c
+++ b/libxfs/xfs_inode_buf.c
@@ -241,7 +241,8 @@ xfs_inode_from_disk(
 	to->di_nblocks = be64_to_cpu(from->di_nblocks);
 	to->di_extsize = be32_to_cpu(from->di_extsize);
 	to->di_nextents = be32_to_cpu(from->di_nextents);
-	to->di_anextents = be16_to_cpu(from->di_anextents);
+	to->di_anextents = XFS_DFORK_NEXTENTS(&ip->i_mount->m_sb, from,
+				XFS_ATTR_FORK);
 	to->di_forkoff = from->di_forkoff;
 	to->di_aformat	= from->di_aformat;
 	to->di_dmevmask	= be32_to_cpu(from->di_dmevmask);
@@ -292,7 +293,8 @@ xfs_inode_to_disk(
 	to->di_nblocks = cpu_to_be64(from->di_nblocks);
 	to->di_extsize = cpu_to_be32(from->di_extsize);
 	to->di_nextents = cpu_to_be32(from->di_nextents);
-	to->di_anextents = cpu_to_be16(from->di_anextents);
+	to->di_anextents_lo =
+		cpu_to_be16((uint32_t)(from->di_anextents) & 0xffff);
 	to->di_forkoff = from->di_forkoff;
 	to->di_aformat = from->di_aformat;
 	to->di_dmevmask = cpu_to_be32(from->di_dmevmask);
@@ -305,6 +307,8 @@ xfs_inode_to_disk(
 		to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.tv_nsec);
 		to->di_flags2 = cpu_to_be64(from->di_flags2);
 		to->di_cowextsize = cpu_to_be32(from->di_cowextsize);
+		to->di_anextents_hi =
+			cpu_to_be16((uint32_t)(from->di_anextents) >> 16);
 		to->di_ino = cpu_to_be64(ip->i_ino);
 		to->di_lsn = cpu_to_be64(lsn);
 		memset(to->di_pad2, 0, sizeof(to->di_pad2));
@@ -343,7 +347,7 @@ xfs_log_dinode_to_disk(
 	to->di_nblocks = cpu_to_be64(from->di_nblocks);
 	to->di_extsize = cpu_to_be32(from->di_extsize);
 	to->di_nextents = cpu_to_be32(from->di_nextents);
-	to->di_anextents = cpu_to_be16(from->di_anextents);
+	to->di_anextents_lo = cpu_to_be16(from->di_anextents_lo);
 	to->di_forkoff = from->di_forkoff;
 	to->di_aformat = from->di_aformat;
 	to->di_dmevmask = cpu_to_be32(from->di_dmevmask);
@@ -357,6 +361,7 @@ xfs_log_dinode_to_disk(
 		to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.t_nsec);
 		to->di_flags2 = cpu_to_be64(from->di_flags2);
 		to->di_cowextsize = cpu_to_be32(from->di_cowextsize);
+		to->di_anextents_hi = cpu_to_be16(from->di_anextents_hi);
 		to->di_ino = cpu_to_be64(from->di_ino);
 		to->di_lsn = cpu_to_be64(from->di_lsn);
 		memcpy(to->di_pad2, from->di_pad2, sizeof(to->di_pad2));
@@ -373,7 +378,9 @@ xfs_dinode_verify_fork(
 	struct xfs_mount	*mp,
 	int			whichfork)
 {
-	uint32_t		di_nextents = XFS_DFORK_NEXTENTS(dip, whichfork);
+	uint32_t		di_nextents;
+
+	di_nextents = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, whichfork);
 
 	switch (XFS_DFORK_FORMAT(dip, whichfork)) {
 	case XFS_DINODE_FMT_LOCAL:
@@ -444,6 +451,9 @@ xfs_dinode_verify(
 	uint16_t		flags;
 	uint64_t		flags2;
 	uint64_t		di_size;
+	int32_t			nextents;
+	int32_t			anextents;
+	int64_t			nblocks;
 
 	if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
 		return __this_address;
@@ -474,10 +484,12 @@ xfs_dinode_verify(
 	if ((S_ISLNK(mode) || S_ISDIR(mode)) && di_size == 0)
 		return __this_address;
 
+	nextents = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_DATA_FORK);
+	anextents = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_ATTR_FORK);
+	nblocks = be64_to_cpu(dip->di_nblocks);
+
 	/* Fork checks carried over from xfs_iformat_fork */
-	if (mode &&
-	    be32_to_cpu(dip->di_nextents) + be16_to_cpu(dip->di_anextents) >
-			be64_to_cpu(dip->di_nblocks))
+	if (mode && nextents + anextents > nblocks)
 		return __this_address;
 
 	if (mode && XFS_DFORK_BOFF(dip) > mp->m_sb.sb_inodesize)
@@ -534,7 +546,7 @@ xfs_dinode_verify(
 		default:
 			return __this_address;
 		}
-		if (dip->di_anextents)
+		if (XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_ATTR_FORK))
 			return __this_address;
 	}
 
diff --git a/libxfs/xfs_inode_fork.c b/libxfs/xfs_inode_fork.c
index a4b5686e..deb04b35 100644
--- a/libxfs/xfs_inode_fork.c
+++ b/libxfs/xfs_inode_fork.c
@@ -205,9 +205,10 @@ xfs_iformat_extents(
 	int			whichfork)
 {
 	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_sb		*sb = &mp->m_sb;
 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
 	int			state = xfs_bmap_fork_to_state(whichfork);
-	int			nex = XFS_DFORK_NEXTENTS(dip, whichfork);
+	int			nex = XFS_DFORK_NEXTENTS(sb, dip, whichfork);
 	int			size = nex * sizeof(xfs_bmbt_rec_t);
 	struct xfs_iext_cursor	icur;
 	struct xfs_bmbt_rec	*dp;
diff --git a/libxfs/xfs_log_format.h b/libxfs/xfs_log_format.h
index 8ef31d71..0e18989d 100644
--- a/libxfs/xfs_log_format.h
+++ b/libxfs/xfs_log_format.h
@@ -397,7 +397,7 @@ struct xfs_log_dinode {
 	xfs_rfsblock_t	di_nblocks;	/* # of direct & btree blocks used */
 	xfs_extlen_t	di_extsize;	/* basic/minimum extent size for file */
 	xfs_extnum_t	di_nextents;	/* number of extents in data fork */
-	xfs_aextnum_t	di_anextents;	/* number of extents in attribute fork*/
+	uint16_t	di_anextents_lo;	/* number of extents in attribute fork*/
 	uint8_t		di_forkoff;	/* attr fork offs, <<3 for 64b align */
 	int8_t		di_aformat;	/* format of attr fork's data */
 	uint32_t	di_dmevmask;	/* DMIG event mask */
@@ -414,7 +414,8 @@ struct xfs_log_dinode {
 	xfs_lsn_t	di_lsn;		/* flush sequence */
 	uint64_t	di_flags2;	/* more random flags */
 	uint32_t	di_cowextsize;	/* basic cow extent size for file */
-	uint8_t		di_pad2[12];	/* more padding for future expansion */
+	uint16_t	di_anextents_hi;
+	uint8_t		di_pad2[10];	/* more padding for future expansion */
 
 	/* fields only written to during inode creation */
 	xfs_ictimestamp_t di_crtime;	/* time created */
diff --git a/libxfs/xfs_types.h b/libxfs/xfs_types.h
index a2005e2d..f5e73c20 100644
--- a/libxfs/xfs_types.h
+++ b/libxfs/xfs_types.h
@@ -13,7 +13,7 @@ typedef uint32_t	xfs_agino_t;	/* inode # within allocation grp */
 typedef uint32_t	xfs_extlen_t;	/* extent length in blocks */
 typedef uint32_t	xfs_agnumber_t;	/* allocation group number */
 typedef int32_t		xfs_extnum_t;	/* # of extents in a file */
-typedef int16_t		xfs_aextnum_t;	/* # extents in an attribute fork */
+typedef int32_t		xfs_aextnum_t;	/* # extents in an attribute fork */
 typedef int64_t		xfs_fsize_t;	/* bytes in a file */
 typedef uint64_t	xfs_ufsize_t;	/* unsigned bytes in a file */
 
@@ -60,7 +60,7 @@ typedef void *		xfs_failaddr_t;
  */
 #define	MAXEXTLEN	((xfs_extlen_t)0x001fffff)	/* 21 bits */
 #define	MAXEXTNUM	((xfs_extnum_t)0x7fffffff)	/* signed int */
-#define	MAXAEXTNUM	((xfs_aextnum_t)0x7fff)		/* signed short */
+#define	MAXAEXTNUM	((xfs_aextnum_t)0x7fffffff)	/* signed int */
 
 /*
  * Minimum and maximum blocksize and sectorsize.
diff --git a/logprint/log_misc.c b/logprint/log_misc.c
index 45f697fc..080941a0 100644
--- a/logprint/log_misc.c
+++ b/logprint/log_misc.c
@@ -440,6 +440,8 @@ static void
 xlog_print_trans_inode_core(
 	struct xfs_log_dinode	*ip)
 {
+    uint32_t naextents;
+
     printf(_("INODE CORE\n"));
     printf(_("magic 0x%hx mode 0%ho version %d format %d\n"),
 	   ip->di_magic, ip->di_mode, (int)ip->di_version,
@@ -451,8 +453,13 @@ xlog_print_trans_inode_core(
     printf(_("size 0x%llx nblocks 0x%llx extsize 0x%x nextents 0x%x\n"),
 	   (unsigned long long)ip->di_size, (unsigned long long)ip->di_nblocks,
 	   ip->di_extsize, ip->di_nextents);
+
+    naextents = ip->di_anextents_lo;
+    if (ip->di_version == 3)
+	    naextents |= ((uint32_t)(ip->di_anextents_hi) << 16);
+
     printf(_("naextents 0x%x forkoff %d dmevmask 0x%x dmstate 0x%hx\n"),
-	   ip->di_anextents, (int)ip->di_forkoff, ip->di_dmevmask,
+	   naextents, (int)ip->di_forkoff, ip->di_dmevmask,
 	   ip->di_dmstate);
     printf(_("flags 0x%x gen 0x%x\n"),
 	   ip->di_flags, ip->di_gen);
diff --git a/logprint/log_print_all.c b/logprint/log_print_all.c
index d3d4c07b..8f4ffe2a 100644
--- a/logprint/log_print_all.c
+++ b/logprint/log_print_all.c
@@ -240,6 +240,8 @@ STATIC void
 xlog_recover_print_inode_core(
 	struct xfs_log_dinode	*di)
 {
+	uint32_t anextents;
+
 	printf(_("	CORE inode:\n"));
 	if (!print_inode)
 		return;
@@ -252,10 +254,15 @@ xlog_recover_print_inode_core(
 	printf(_("		atime:%d  mtime:%d  ctime:%d\n"),
 	       di->di_atime.t_sec, di->di_mtime.t_sec, di->di_ctime.t_sec);
 	printf(_("		flushiter:%d\n"), di->di_flushiter);
+
+	anextents = di->di_anextents_lo;
+	if (di->di_version == 3)
+		anextents |= ((uint32_t)(di->di_anextents_hi) << 16);
+
 	printf(_("		size:0x%llx  nblks:0x%llx  exsize:%d  "
 	     "nextents:%d  anextents:%d\n"), (unsigned long long)
 	       di->di_size, (unsigned long long)di->di_nblocks,
-	       di->di_extsize, di->di_nextents, (int)di->di_anextents);
+		di->di_extsize, di->di_nextents, (int)anextents);
 	printf(_("		forkoff:%d  dmevmask:0x%x  dmstate:%d  flags:0x%x  "
 	     "gen:%u\n"),
 	       (int)di->di_forkoff, di->di_dmevmask, (int)di->di_dmstate,
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 606f79da..9be87ef8 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -3018,6 +3018,7 @@ sb_set_features(
 		sbp->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_SPINODES;
 	}
 
+	sbp->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_32BIT_AEXT_CNTR;
 }
 
 /*
diff --git a/repair/attr_repair.c b/repair/attr_repair.c
index 9a44f610..2e4bcc68 100644
--- a/repair/attr_repair.c
+++ b/repair/attr_repair.c
@@ -983,7 +983,7 @@ process_longform_attr(
 
 	if ( bno == NULLFSBLOCK ) {
 		if (dip->di_aformat == XFS_DINODE_FMT_EXTENTS &&
-				be16_to_cpu(dip->di_anextents) == 0)
+			XFS_DFORK_NEXTENTS(&mp->m_sb, dip, XFS_ATTR_FORK) == 0)
 			return(0); /* the kernel can handle this state */
 		do_warn(
 	_("block 0 of inode %" PRIu64 " attribute fork is missing\n"),
diff --git a/repair/dinode.c b/repair/dinode.c
index 8af2cb25..7247e10a 100644
--- a/repair/dinode.c
+++ b/repair/dinode.c
@@ -68,10 +68,12 @@ _("clearing inode %" PRIu64 " attributes\n"), ino_num);
 		fprintf(stderr,
 _("would have cleared inode %" PRIu64 " attributes\n"), ino_num);
 
-	if (be16_to_cpu(dino->di_anextents) != 0)  {
+	if (XFS_DFORK_NEXTENTS(&mp->m_sb, dino, XFS_ATTR_FORK) != 0)  {
 		if (no_modify)
 			return(1);
-		dino->di_anextents = cpu_to_be16(0);
+		dino->di_anextents_lo = cpu_to_be16(0);
+		if (dino->di_version == 3)
+			dino->di_anextents_hi = cpu_to_be16(0);
 	}
 
 	if (dino->di_aformat != XFS_DINODE_FMT_EXTENTS)  {
@@ -999,7 +1001,7 @@ process_exinode(
 	lino = XFS_AGINO_TO_INO(mp, agno, ino);
 	rp = (xfs_bmbt_rec_t *)XFS_DFORK_PTR(dip, whichfork);
 	*tot = 0;
-	numrecs = XFS_DFORK_NEXTENTS(dip, whichfork);
+	numrecs = XFS_DFORK_NEXTENTS(&mp->m_sb, dip, whichfork);
 
 	/*
 	 * We've already decided on the maximum number of extents on the inode,
@@ -1836,6 +1838,7 @@ _("bad attr fork offset %d in inode %" PRIu64 ", max=%d\n"),
  */
 static int
 process_inode_blocks_and_extents(
+	xfs_mount_t	*mp,
 	xfs_dinode_t	*dino,
 	xfs_rfsblock_t	nblocks,
 	uint64_t	nextents,
@@ -1843,6 +1846,8 @@ process_inode_blocks_and_extents(
 	xfs_ino_t	lino,
 	int		*dirty)
 {
+	int32_t		anextents_disk;
+
 	if (nblocks != be64_to_cpu(dino->di_nblocks))  {
 		if (!no_modify)  {
 			do_warn(
@@ -1888,19 +1893,21 @@ _("too many attr fork extents (%" PRIu64 ") in inode %" PRIu64 "\n"),
 			anextents, lino);
 		return 1;
 	}
-	if (anextents != be16_to_cpu(dino->di_anextents))  {
+
+	anextents_disk = XFS_DFORK_NEXTENTS(&mp->m_sb, dino, XFS_ATTR_FORK);
+	if (anextents != anextents_disk)  {
 		if (!no_modify)  {
 			do_warn(
 _("correcting anextents for inode %" PRIu64 ", was %d - counted %" PRIu64 "\n"),
-				lino,
-				be16_to_cpu(dino->di_anextents), anextents);
-			dino->di_anextents = cpu_to_be16(anextents);
+				lino, anextents_disk, anextents);
+			dino->di_anextents_lo = cpu_to_be16(anextents & 0xffff);
+			if (dino->di_version == 3)
+				dino->di_anextents_hi = cpu_to_be16(anextents >> 16);
 			*dirty = 1;
 		} else  {
 			do_warn(
 _("bad anextents %d for inode %" PRIu64 ", would reset to %" PRIu64 "\n"),
-				be16_to_cpu(dino->di_anextents),
-				lino, anextents);
+				anextents_disk, lino, anextents);
 		}
 	}
 
@@ -2063,7 +2070,7 @@ process_inode_attr_fork(
 		return 0;
 	}
 
-	*anextents = be16_to_cpu(dino->di_anextents);
+	*anextents = XFS_DFORK_NEXTENTS(&mp->m_sb, dino, XFS_ATTR_FORK);
 	if (*anextents > be64_to_cpu(dino->di_nblocks))
 		*anextents = 1;
 
@@ -2803,7 +2810,7 @@ _("Bad CoW extent size %u on inode %" PRIu64 ", "),
 	/*
 	 * correct space counters if required
 	 */
-	if (process_inode_blocks_and_extents(dino, totblocks + atotblocks,
+	if (process_inode_blocks_and_extents(mp, dino, totblocks + atotblocks,
 			nextents, anextents, lino, dirty) != 0)
 		goto clear_bad_out;
 
-- 
2.19.1