Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 773 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
new file mode 100644
index 000000000..758aacd81
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -0,0 +1,773 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_ag.h"
+#include "xfs_inode.h"
+#include "xfs_errortag.h"
+#include "xfs_error.h"
+#include "xfs_icache.h"
+#include "xfs_trans.h"
+#include "xfs_ialloc.h"
+#include "xfs_dir2.h"
+
+#include <linux/iversion.h>
+
+/*
+ * If we are doing readahead on an inode buffer, we might be in log recovery
+ * reading an inode allocation buffer that hasn't yet been replayed, and hence
+ * has not had the inode cores stamped into it. Hence for readahead, the buffer
+ * may be potentially invalid.
+ *
+ * If the readahead buffer is invalid, we need to mark it with an error and
+ * clear the DONE status of the buffer so that a followup read will re-read it
+ * from disk. We don't report the error otherwise to avoid warnings during log
+ * recovery and we don't get unnecessary panics on debug kernels. We use EIO here
+ * because all we want to do is say readahead failed; there is no-one to report
+ * the error to, so this will distinguish it from a non-ra verifier failure.
+ * Changes to this readahead error behaviour also need to be reflected in
+ * xfs_dquot_buf_readahead_verify().
+ */
+static void
+xfs_inode_buf_verify(
+	struct xfs_buf	*bp,
+	bool		readahead)
+{
+	struct xfs_mount *mp = bp->b_mount;
+	int		i;
+	int		ni;
+
+	/*
+	 * Validate the magic number and version of every inode in the buffer
+	 */
+	ni = XFS_BB_TO_FSB(mp, bp->b_length) * mp->m_sb.sb_inopblock;
+	for (i = 0; i < ni; i++) {
+		struct xfs_dinode	*dip;
+		xfs_agino_t		unlinked_ino;
+		int			di_ok;
+
+		dip = xfs_buf_offset(bp, (i << mp->m_sb.sb_inodelog));
+		unlinked_ino = be32_to_cpu(dip->di_next_unlinked);
+		di_ok = xfs_verify_magic16(bp, dip->di_magic) &&
+			xfs_dinode_good_version(mp, dip->di_version) &&
+			xfs_verify_agino_or_null(bp->b_pag, unlinked_ino);
+		if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
+						XFS_ERRTAG_ITOBP_INOTOBP))) {
+			if (readahead) {
+				bp->b_flags &= ~XBF_DONE;
+				xfs_buf_ioerror(bp, -EIO);
+				return;
+			}
+
+#ifdef DEBUG
+			xfs_alert(mp,
+				"bad inode magic/vsn daddr %lld #%d (magic=%x)",
+				(unsigned long long)xfs_buf_daddr(bp), i,
+				be16_to_cpu(dip->di_magic));
+#endif
+			xfs_buf_verifier_error(bp, -EFSCORRUPTED,
+					__func__, dip, sizeof(*dip),
+					NULL);
+			return;
+		}
+	}
+}
+
+
+static void
+xfs_inode_buf_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp, false);
+}
+
+static void
+xfs_inode_buf_readahead_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp, true);
+}
+
+static void
+xfs_inode_buf_write_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp, false);
+}
+
+const struct xfs_buf_ops xfs_inode_buf_ops = {
+	.name = "xfs_inode",
+	.magic16 = { cpu_to_be16(XFS_DINODE_MAGIC),
+		     cpu_to_be16(XFS_DINODE_MAGIC) },
+	.verify_read = xfs_inode_buf_read_verify,
+	.verify_write = xfs_inode_buf_write_verify,
+};
+
+const struct xfs_buf_ops xfs_inode_buf_ra_ops = {
+	.name = "xfs_inode_ra",
+	.magic16 = { cpu_to_be16(XFS_DINODE_MAGIC),
+		     cpu_to_be16(XFS_DINODE_MAGIC) },
+	.verify_read = xfs_inode_buf_readahead_verify,
+	.verify_write = xfs_inode_buf_write_verify,
+};
+
+
+/*
+ * This routine is called to map an inode to the buffer containing the on-disk
+ * version of the inode.  It returns a pointer to the buffer containing the
+ * on-disk inode in the bpp parameter.
+ */
+int
+xfs_imap_to_bp(
+	struct xfs_mount	*mp,
+	struct xfs_trans	*tp,
+	struct xfs_imap		*imap,
+	struct xfs_buf		**bpp)
+{
+	return xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap->im_blkno,
+				   imap->im_len, XBF_UNMAPPED, bpp,
+				   &xfs_inode_buf_ops);
+}
+
+static inline struct timespec64 xfs_inode_decode_bigtime(uint64_t ts)
+{
+	struct timespec64	tv;
+	uint32_t		n;
+
+	tv.tv_sec = xfs_bigtime_to_unix(div_u64_rem(ts, NSEC_PER_SEC, &n));
+	tv.tv_nsec = n;
+
+	return tv;
+}
+
+/* Convert an ondisk timestamp to an incore timestamp. */
+struct timespec64
+xfs_inode_from_disk_ts(
+	struct xfs_dinode		*dip,
+	const xfs_timestamp_t		ts)
+{
+	struct timespec64		tv;
+	struct xfs_legacy_timestamp	*lts;
+
+	if (xfs_dinode_has_bigtime(dip))
+		return xfs_inode_decode_bigtime(be64_to_cpu(ts));
+
+	lts = (struct xfs_legacy_timestamp *)&ts;
+	tv.tv_sec = (int)be32_to_cpu(lts->t_sec);
+	tv.tv_nsec = (int)be32_to_cpu(lts->t_nsec);
+
+	return tv;
+}
+
+int
+xfs_inode_from_disk(
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*from)
+{
+	struct inode		*inode = VFS_I(ip);
+	int			error;
+	xfs_failaddr_t		fa;
+
+	ASSERT(ip->i_cowfp == NULL);
+
+	fa = xfs_dinode_verify(ip->i_mount, ip->i_ino, from);
+	if (fa) {
+		xfs_inode_verifier_error(ip, -EFSCORRUPTED, "dinode", from,
+				sizeof(*from), fa);
+		return -EFSCORRUPTED;
+	}
+
+	/*
+	 * First get the permanent information that is needed to allocate an
+	 * inode. If the inode is unused, mode is zero and we shouldn't mess
+	 * with the uninitialized part of it.
+	 */
+	if (!xfs_has_v3inodes(ip->i_mount))
+		ip->i_flushiter = be16_to_cpu(from->di_flushiter);
+	inode->i_generation = be32_to_cpu(from->di_gen);
+	inode->i_mode = be16_to_cpu(from->di_mode);
+	if (!inode->i_mode)
+		return 0;
+
+	/*
+	 * Convert v1 inodes immediately to v2 inode format as this is the
+	 * minimum inode version format we support in the rest of the code.
+	 * They will also be unconditionally written back to disk as v2 inodes.
+	 */
+	if (unlikely(from->di_version == 1)) {
+		set_nlink(inode, be16_to_cpu(from->di_onlink));
+		ip->i_projid = 0;
+	} else {
+		set_nlink(inode, be32_to_cpu(from->di_nlink));
+		ip->i_projid = (prid_t)be16_to_cpu(from->di_projid_hi) << 16 |
+					be16_to_cpu(from->di_projid_lo);
+	}
+
+	i_uid_write(inode, be32_to_cpu(from->di_uid));
+	i_gid_write(inode, be32_to_cpu(from->di_gid));
+
+	/*
+	 * Time is signed, so need to convert to signed 32 bit before
+	 * storing in inode timestamp which may be 64 bit. Otherwise
+	 * a time before epoch is converted to a time long after epoch
+	 * on 64 bit systems.
+	 */
+	inode->i_atime = xfs_inode_from_disk_ts(from, from->di_atime);
+	inode->i_mtime = xfs_inode_from_disk_ts(from, from->di_mtime);
+	inode->i_ctime = xfs_inode_from_disk_ts(from, from->di_ctime);
+
+	ip->i_disk_size = be64_to_cpu(from->di_size);
+	ip->i_nblocks = be64_to_cpu(from->di_nblocks);
+	ip->i_extsize = be32_to_cpu(from->di_extsize);
+	ip->i_forkoff = from->di_forkoff;
+	ip->i_diflags = be16_to_cpu(from->di_flags);
+	ip->i_next_unlinked = be32_to_cpu(from->di_next_unlinked);
+
+	if (from->di_dmevmask || from->di_dmstate)
+		xfs_iflags_set(ip, XFS_IPRESERVE_DM_FIELDS);
+
+	if (xfs_has_v3inodes(ip->i_mount)) {
+		inode_set_iversion_queried(inode,
+					   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);
+		ip->i_cowextsize = be32_to_cpu(from->di_cowextsize);
+	}
+
+	error = xfs_iformat_data_fork(ip, from);
+	if (error)
+		return error;
+	if (from->di_forkoff) {
+		error = xfs_iformat_attr_fork(ip, from);
+		if (error)
+			goto out_destroy_data_fork;
+	}
+	if (xfs_is_reflink_inode(ip))
+		xfs_ifork_init_cow(ip);
+	return 0;
+
+out_destroy_data_fork:
+	xfs_idestroy_fork(&ip->i_df);
+	return error;
+}
+
+/* Convert an incore timestamp to an ondisk timestamp. */
+static inline xfs_timestamp_t
+xfs_inode_to_disk_ts(
+	struct xfs_inode		*ip,
+	const struct timespec64		tv)
+{
+	struct xfs_legacy_timestamp	*lts;
+	xfs_timestamp_t			ts;
+
+	if (xfs_inode_has_bigtime(ip))
+		return cpu_to_be64(xfs_inode_encode_bigtime(tv));
+
+	lts = (struct xfs_legacy_timestamp *)&ts;
+	lts->t_sec = cpu_to_be32(tv.tv_sec);
+	lts->t_nsec = cpu_to_be32(tv.tv_nsec);
+
+	return ts;
+}
+
+static inline void
+xfs_inode_to_disk_iext_counters(
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*to)
+{
+	if (xfs_inode_has_large_extent_counts(ip)) {
+		to->di_big_nextents = cpu_to_be64(xfs_ifork_nextents(&ip->i_df));
+		to->di_big_anextents = cpu_to_be32(xfs_ifork_nextents(&ip->i_af));
+		/*
+		 * We might be upgrading the inode to use larger extent counters
+		 * than was previously used. Hence zero the unused field.
+		 */
+		to->di_nrext64_pad = cpu_to_be16(0);
+	} else {
+		to->di_nextents = cpu_to_be32(xfs_ifork_nextents(&ip->i_df));
+		to->di_anextents = cpu_to_be16(xfs_ifork_nextents(&ip->i_af));
+	}
+}
+
+void
+xfs_inode_to_disk(
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*to,
+	xfs_lsn_t		lsn)
+{
+	struct inode		*inode = VFS_I(ip);
+
+	to->di_magic = cpu_to_be16(XFS_DINODE_MAGIC);
+	to->di_onlink = 0;
+
+	to->di_format = xfs_ifork_format(&ip->i_df);
+	to->di_uid = cpu_to_be32(i_uid_read(inode));
+	to->di_gid = cpu_to_be32(i_gid_read(inode));
+	to->di_projid_lo = cpu_to_be16(ip->i_projid & 0xffff);
+	to->di_projid_hi = cpu_to_be16(ip->i_projid >> 16);
+
+	to->di_atime = xfs_inode_to_disk_ts(ip, inode->i_atime);
+	to->di_mtime = xfs_inode_to_disk_ts(ip, inode->i_mtime);
+	to->di_ctime = xfs_inode_to_disk_ts(ip, inode->i_ctime);
+	to->di_nlink = cpu_to_be32(inode->i_nlink);
+	to->di_gen = cpu_to_be32(inode->i_generation);
+	to->di_mode = cpu_to_be16(inode->i_mode);
+
+	to->di_size = cpu_to_be64(ip->i_disk_size);
+	to->di_nblocks = cpu_to_be64(ip->i_nblocks);
+	to->di_extsize = cpu_to_be32(ip->i_extsize);
+	to->di_forkoff = ip->i_forkoff;
+	to->di_aformat = xfs_ifork_format(&ip->i_af);
+	to->di_flags = cpu_to_be16(ip->i_diflags);
+
+	if (xfs_has_v3inodes(ip->i_mount)) {
+		to->di_version = 3;
+		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);
+		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);
+		memset(to->di_pad2, 0, sizeof(to->di_pad2));
+		uuid_copy(&to->di_uuid, &ip->i_mount->m_sb.sb_meta_uuid);
+		to->di_v3_pad = 0;
+	} else {
+		to->di_version = 2;
+		to->di_flushiter = cpu_to_be16(ip->i_flushiter);
+		memset(to->di_v2_pad, 0, sizeof(to->di_v2_pad));
+	}
+
+	xfs_inode_to_disk_iext_counters(ip, to);
+}
+
+static xfs_failaddr_t
+xfs_dinode_verify_fork(
+	struct xfs_dinode	*dip,
+	struct xfs_mount	*mp,
+	int			whichfork)
+{
+	xfs_extnum_t		di_nextents;
+	xfs_extnum_t		max_extents;
+	mode_t			mode = be16_to_cpu(dip->di_mode);
+	uint32_t		fork_size = XFS_DFORK_SIZE(dip, mp, whichfork);
+	uint32_t		fork_format = XFS_DFORK_FORMAT(dip, whichfork);
+
+	di_nextents = xfs_dfork_nextents(dip, whichfork);
+
+	/*
+	 * For fork types that can contain local data, check that the fork
+	 * format matches the size of local data contained within the fork.
+	 *
+	 * For all types, check that when the size says the should be in extent
+	 * or btree format, the inode isn't claiming it is in local format.
+	 */
+	if (whichfork == XFS_DATA_FORK) {
+		if (S_ISDIR(mode) || S_ISLNK(mode)) {
+			if (be64_to_cpu(dip->di_size) <= fork_size &&
+			    fork_format != XFS_DINODE_FMT_LOCAL)
+				return __this_address;
+		}
+
+		if (be64_to_cpu(dip->di_size) > fork_size &&
+		    fork_format == XFS_DINODE_FMT_LOCAL)
+			return __this_address;
+	}
+
+	switch (fork_format) {
+	case XFS_DINODE_FMT_LOCAL:
+		/*
+		 * No local regular files yet.
+		 */
+		if (S_ISREG(mode) && whichfork == XFS_DATA_FORK)
+			return __this_address;
+		if (di_nextents)
+			return __this_address;
+		break;
+	case XFS_DINODE_FMT_EXTENTS:
+		if (di_nextents > XFS_DFORK_MAXEXT(dip, mp, whichfork))
+			return __this_address;
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		max_extents = xfs_iext_max_nextents(
+					xfs_dinode_has_large_extent_counts(dip),
+					whichfork);
+		if (di_nextents > max_extents)
+			return __this_address;
+		break;
+	default:
+		return __this_address;
+	}
+	return NULL;
+}
+
+static xfs_failaddr_t
+xfs_dinode_verify_forkoff(
+	struct xfs_dinode	*dip,
+	struct xfs_mount	*mp)
+{
+	if (!dip->di_forkoff)
+		return NULL;
+
+	switch (dip->di_format)  {
+	case XFS_DINODE_FMT_DEV:
+		if (dip->di_forkoff != (roundup(sizeof(xfs_dev_t), 8) >> 3))
+			return __this_address;
+		break;
+	case XFS_DINODE_FMT_LOCAL:	/* fall through ... */
+	case XFS_DINODE_FMT_EXTENTS:    /* fall through ... */
+	case XFS_DINODE_FMT_BTREE:
+		if (dip->di_forkoff >= (XFS_LITINO(mp) >> 3))
+			return __this_address;
+		break;
+	default:
+		return __this_address;
+	}
+	return NULL;
+}
+
+static xfs_failaddr_t
+xfs_dinode_verify_nrext64(
+	struct xfs_mount	*mp,
+	struct xfs_dinode	*dip)
+{
+	if (xfs_dinode_has_large_extent_counts(dip)) {
+		if (!xfs_has_large_extent_counts(mp))
+			return __this_address;
+		if (dip->di_nrext64_pad != 0)
+			return __this_address;
+	} else if (dip->di_version >= 3) {
+		if (dip->di_v3_pad != 0)
+			return __this_address;
+	}
+
+	return NULL;
+}
+
+xfs_failaddr_t
+xfs_dinode_verify(
+	struct xfs_mount	*mp,
+	xfs_ino_t		ino,
+	struct xfs_dinode	*dip)
+{
+	xfs_failaddr_t		fa;
+	uint16_t		mode;
+	uint16_t		flags;
+	uint64_t		flags2;
+	uint64_t		di_size;
+	xfs_extnum_t		nextents;
+	xfs_extnum_t		naextents;
+	xfs_filblks_t		nblocks;
+
+	if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC))
+		return __this_address;
+
+	/* Verify v3 integrity information first */
+	if (dip->di_version >= 3) {
+		if (!xfs_has_v3inodes(mp))
+			return __this_address;
+		if (!xfs_verify_cksum((char *)dip, mp->m_sb.sb_inodesize,
+				      XFS_DINODE_CRC_OFF))
+			return __this_address;
+		if (be64_to_cpu(dip->di_ino) != ino)
+			return __this_address;
+		if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_meta_uuid))
+			return __this_address;
+	}
+
+	/* don't allow invalid i_size */
+	di_size = be64_to_cpu(dip->di_size);
+	if (di_size & (1ULL << 63))
+		return __this_address;
+
+	mode = be16_to_cpu(dip->di_mode);
+	if (mode && xfs_mode_to_ftype(mode) == XFS_DIR3_FT_UNKNOWN)
+		return __this_address;
+
+	/* No zero-length symlinks/dirs. */
+	if ((S_ISLNK(mode) || S_ISDIR(mode)) && di_size == 0)
+		return __this_address;
+
+	fa = xfs_dinode_verify_nrext64(mp, dip);
+	if (fa)
+		return fa;
+
+	nextents = xfs_dfork_data_extents(dip);
+	naextents = xfs_dfork_attr_extents(dip);
+	nblocks = be64_to_cpu(dip->di_nblocks);
+
+	/* Fork checks carried over from xfs_iformat_fork */
+	if (mode && nextents + naextents > nblocks)
+		return __this_address;
+
+	if (S_ISDIR(mode) && nextents > mp->m_dir_geo->max_extents)
+		return __this_address;
+
+	if (mode && XFS_DFORK_BOFF(dip) > mp->m_sb.sb_inodesize)
+		return __this_address;
+
+	flags = be16_to_cpu(dip->di_flags);
+
+	if (mode && (flags & XFS_DIFLAG_REALTIME) && !mp->m_rtdev_targp)
+		return __this_address;
+
+	/* check for illegal values of forkoff */
+	fa = xfs_dinode_verify_forkoff(dip, mp);
+	if (fa)
+		return fa;
+
+	/* Do we have appropriate data fork formats for the mode? */
+	switch (mode & S_IFMT) {
+	case S_IFIFO:
+	case S_IFCHR:
+	case S_IFBLK:
+	case S_IFSOCK:
+		if (dip->di_format != XFS_DINODE_FMT_DEV)
+			return __this_address;
+		break;
+	case S_IFREG:
+	case S_IFLNK:
+	case S_IFDIR:
+		fa = xfs_dinode_verify_fork(dip, mp, XFS_DATA_FORK);
+		if (fa)
+			return fa;
+		break;
+	case 0:
+		/* Uninitialized inode ok. */
+		break;
+	default:
+		return __this_address;
+	}
+
+	if (dip->di_forkoff) {
+		fa = xfs_dinode_verify_fork(dip, mp, XFS_ATTR_FORK);
+		if (fa)
+			return fa;
+	} else {
+		/*
+		 * If there is no fork offset, this may be a freshly-made inode
+		 * in a new disk cluster, in which case di_aformat is zeroed.
+		 * Otherwise, such an inode must be in EXTENTS format; this goes
+		 * for freed inodes as well.
+		 */
+		switch (dip->di_aformat) {
+		case 0:
+		case XFS_DINODE_FMT_EXTENTS:
+			break;
+		default:
+			return __this_address;
+		}
+		if (naextents)
+			return __this_address;
+	}
+
+	/* extent size hint validation */
+	fa = xfs_inode_validate_extsize(mp, be32_to_cpu(dip->di_extsize),
+			mode, flags);
+	if (fa)
+		return fa;
+
+	/* only version 3 or greater inodes are extensively verified here */
+	if (dip->di_version < 3)
+		return NULL;
+
+	flags2 = be64_to_cpu(dip->di_flags2);
+
+	/* don't allow reflink/cowextsize if we don't have reflink */
+	if ((flags2 & (XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE)) &&
+	     !xfs_has_reflink(mp))
+		return __this_address;
+
+	/* only regular files get reflink */
+	if ((flags2 & XFS_DIFLAG2_REFLINK) && (mode & S_IFMT) != S_IFREG)
+		return __this_address;
+
+	/* don't let reflink and realtime mix */
+	if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags & XFS_DIFLAG_REALTIME))
+		return __this_address;
+
+	/* 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) &&
+	    !xfs_has_bigtime(mp))
+		return __this_address;
+
+	return NULL;
+}
+
+void
+xfs_dinode_calc_crc(
+	struct xfs_mount	*mp,
+	struct xfs_dinode	*dip)
+{
+	uint32_t		crc;
+
+	if (dip->di_version < 3)
+		return;
+
+	ASSERT(xfs_has_crc(mp));
+	crc = xfs_start_cksum_update((char *)dip, mp->m_sb.sb_inodesize,
+			      XFS_DINODE_CRC_OFF);
+	dip->di_crc = xfs_end_cksum(crc);
+}
+
+/*
+ * Validate di_extsize hint.
+ *
+ * 1. Extent size hint is only valid for directories and regular files.
+ * 2. FS_XFLAG_EXTSIZE is only valid for regular files.
+ * 3. FS_XFLAG_EXTSZINHERIT is only valid for directories.
+ * 4. Hint cannot be larger than MAXTEXTLEN.
+ * 5. Can be changed on directories at any time.
+ * 6. Hint value of 0 turns off hints, clears inode flags.
+ * 7. Extent size must be a multiple of the appropriate block size.
+ *    For realtime files, this is the rt extent size.
+ * 8. For non-realtime files, the extent size hint must be limited
+ *    to half the AG size to avoid alignment extending the extent beyond the
+ *    limits of the AG.
+ */
+xfs_failaddr_t
+xfs_inode_validate_extsize(
+	struct xfs_mount		*mp,
+	uint32_t			extsize,
+	uint16_t			mode,
+	uint16_t			flags)
+{
+	bool				rt_flag;
+	bool				hint_flag;
+	bool				inherit_flag;
+	uint32_t			extsize_bytes;
+	uint32_t			blocksize_bytes;
+
+	rt_flag = (flags & XFS_DIFLAG_REALTIME);
+	hint_flag = (flags & XFS_DIFLAG_EXTSIZE);
+	inherit_flag = (flags & XFS_DIFLAG_EXTSZINHERIT);
+	extsize_bytes = XFS_FSB_TO_B(mp, extsize);
+
+	/*
+	 * This comment describes a historic gap in this verifier function.
+	 *
+	 * For a directory with both RTINHERIT and EXTSZINHERIT flags set, this
+	 * function has never checked that the extent size hint is an integer
+	 * multiple of the realtime extent size.  Since we allow users to set
+	 * this combination  on non-rt filesystems /and/ to change the rt
+	 * extent size when adding a rt device to a filesystem, the net effect
+	 * is that users can configure a filesystem anticipating one rt
+	 * geometry and change their minds later.  Directories do not use the
+	 * extent size hint, so this is harmless for them.
+	 *
+	 * If a directory with a misaligned extent size hint is allowed to
+	 * propagate that hint into a new regular realtime file, the result
+	 * is that the inode cluster buffer verifier will trigger a corruption
+	 * shutdown the next time it is run, because the verifier has always
+	 * enforced the alignment rule for regular files.
+	 *
+	 * Because we allow administrators to set a new rt extent size when
+	 * adding a rt section, we cannot add a check to this verifier because
+	 * that will result a new source of directory corruption errors when
+	 * reading an existing filesystem.  Instead, we rely on callers to
+	 * decide when alignment checks are appropriate, and fix things up as
+	 * needed.
+	 */
+
+	if (rt_flag)
+		blocksize_bytes = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize);
+	else
+		blocksize_bytes = mp->m_sb.sb_blocksize;
+
+	if ((hint_flag || inherit_flag) && !(S_ISDIR(mode) || S_ISREG(mode)))
+		return __this_address;
+
+	if (hint_flag && !S_ISREG(mode))
+		return __this_address;
+
+	if (inherit_flag && !S_ISDIR(mode))
+		return __this_address;
+
+	if ((hint_flag || inherit_flag) && extsize == 0)
+		return __this_address;
+
+	/* free inodes get flags set to zero but extsize remains */
+	if (mode && !(hint_flag || inherit_flag) && extsize != 0)
+		return __this_address;
+
+	if (extsize_bytes % blocksize_bytes)
+		return __this_address;
+
+	if (extsize > XFS_MAX_BMBT_EXTLEN)
+		return __this_address;
+
+	if (!rt_flag && extsize > mp->m_sb.sb_agblocks / 2)
+		return __this_address;
+
+	return NULL;
+}
+
+/*
+ * Validate di_cowextsize hint.
+ *
+ * 1. CoW extent size hint can only be set if reflink is enabled on the fs.
+ *    The inode does not have to have any shared blocks, but it must be a v3.
+ * 2. FS_XFLAG_COWEXTSIZE is only valid for directories and regular files;
+ *    for a directory, the hint is propagated to new files.
+ * 3. Can be changed on files & directories at any time.
+ * 4. Hint value of 0 turns off hints, clears inode flags.
+ * 5. Extent size must be a multiple of the appropriate block size.
+ * 6. The extent size hint must be limited to half the AG size to avoid
+ *    alignment extending the extent beyond the limits of the AG.
+ */
+xfs_failaddr_t
+xfs_inode_validate_cowextsize(
+	struct xfs_mount		*mp,
+	uint32_t			cowextsize,
+	uint16_t			mode,
+	uint16_t			flags,
+	uint64_t			flags2)
+{
+	bool				rt_flag;
+	bool				hint_flag;
+	uint32_t			cowextsize_bytes;
+
+	rt_flag = (flags & XFS_DIFLAG_REALTIME);
+	hint_flag = (flags2 & XFS_DIFLAG2_COWEXTSIZE);
+	cowextsize_bytes = XFS_FSB_TO_B(mp, cowextsize);
+
+	if (hint_flag && !xfs_has_reflink(mp))
+		return __this_address;
+
+	if (hint_flag && !(S_ISDIR(mode) || S_ISREG(mode)))
+		return __this_address;
+
+	if (hint_flag && cowextsize == 0)
+		return __this_address;
+
+	/* free inodes get flags set to zero but cowextsize remains */
+	if (mode && !hint_flag && cowextsize != 0)
+		return __this_address;
+
+	if (hint_flag && rt_flag)
+		return __this_address;
+
+	if (cowextsize_bytes % mp->m_sb.sb_blocksize)
+		return __this_address;
+
+	if (cowextsize > XFS_MAX_BMBT_EXTLEN)
+		return __this_address;
+
+	if (cowextsize > mp->m_sb.sb_agblocks / 2)
+		return __this_address;
+
+	return NULL;
+}