Merge branch 'for-6.15/amd_sfh' into for-linus

From: Mario Limonciello <mario.limonciello@amd.com>

Some platforms include a human presence detection (HPD) sensor. When
enabled and a user is detected a wake event will be emitted from the
sensor fusion hub that software can react to.

Example use cases are "wake from suspend on approach" or to "lock
when leaving".

This is currently enabled by default on supported systems, but users
can't control it. This essentially means that wake on approach is
enabled which is a really surprising behavior to users that don't
expect it.

Instead of defaulting to enabled add a sysfs knob that users can
use to enable the feature if desirable and set it to disabled by
default.

1 files changed, 1035 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.c b/fs/xfs/libxfs/xfs_rtrmap_btree.c
new file mode 100644
index 0000000000000..e4ec36943cb7c
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_rtrmap_btree.c
@@ -0,0 +1,1035 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2018-2024 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#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_bit.h"
+#include "xfs_sb.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_alloc.h"
+#include "xfs_btree.h"
+#include "xfs_btree_staging.h"
+#include "xfs_metafile.h"
+#include "xfs_rmap.h"
+#include "xfs_rtrmap_btree.h"
+#include "xfs_trace.h"
+#include "xfs_cksum.h"
+#include "xfs_error.h"
+#include "xfs_extent_busy.h"
+#include "xfs_rtgroup.h"
+#include "xfs_bmap.h"
+#include "xfs_health.h"
+#include "xfs_buf_mem.h"
+#include "xfs_btree_mem.h"
+
+static struct kmem_cache	*xfs_rtrmapbt_cur_cache;
+
+/*
+ * Realtime Reverse Map btree.
+ *
+ * This is a btree used to track the owner(s) of a given extent in the realtime
+ * device.  See the comments in xfs_rmap_btree.c for more information.
+ *
+ * This tree is basically the same as the regular rmap btree except that it
+ * is rooted in an inode and does not live in free space.
+ */
+
+static struct xfs_btree_cur *
+xfs_rtrmapbt_dup_cursor(
+	struct xfs_btree_cur	*cur)
+{
+	return xfs_rtrmapbt_init_cursor(cur->bc_tp, to_rtg(cur->bc_group));
+}
+
+STATIC int
+xfs_rtrmapbt_get_minrecs(
+	struct xfs_btree_cur	*cur,
+	int			level)
+{
+	if (level == cur->bc_nlevels - 1) {
+		struct xfs_ifork	*ifp = xfs_btree_ifork_ptr(cur);
+
+		return xfs_rtrmapbt_maxrecs(cur->bc_mp, ifp->if_broot_bytes,
+				level == 0) / 2;
+	}
+
+	return cur->bc_mp->m_rtrmap_mnr[level != 0];
+}
+
+STATIC int
+xfs_rtrmapbt_get_maxrecs(
+	struct xfs_btree_cur	*cur,
+	int			level)
+{
+	if (level == cur->bc_nlevels - 1) {
+		struct xfs_ifork	*ifp = xfs_btree_ifork_ptr(cur);
+
+		return xfs_rtrmapbt_maxrecs(cur->bc_mp, ifp->if_broot_bytes,
+				level == 0);
+	}
+
+	return cur->bc_mp->m_rtrmap_mxr[level != 0];
+}
+
+/* Calculate number of records in the ondisk realtime rmap btree inode root. */
+unsigned int
+xfs_rtrmapbt_droot_maxrecs(
+	unsigned int		blocklen,
+	bool			leaf)
+{
+	blocklen -= sizeof(struct xfs_rtrmap_root);
+
+	if (leaf)
+		return blocklen / sizeof(struct xfs_rmap_rec);
+	return blocklen / (2 * sizeof(struct xfs_rmap_key) +
+			sizeof(xfs_rtrmap_ptr_t));
+}
+
+/*
+ * Get the maximum records we could store in the on-disk format.
+ *
+ * For non-root nodes this is equivalent to xfs_rtrmapbt_get_maxrecs, but
+ * for the root node this checks the available space in the dinode fork
+ * so that we can resize the in-memory buffer to match it.  After a
+ * resize to the maximum size this function returns the same value
+ * as xfs_rtrmapbt_get_maxrecs for the root node, too.
+ */
+STATIC int
+xfs_rtrmapbt_get_dmaxrecs(
+	struct xfs_btree_cur	*cur,
+	int			level)
+{
+	if (level != cur->bc_nlevels - 1)
+		return cur->bc_mp->m_rtrmap_mxr[level != 0];
+	return xfs_rtrmapbt_droot_maxrecs(cur->bc_ino.forksize, level == 0);
+}
+
+/*
+ * Convert the ondisk record's offset field into the ondisk key's offset field.
+ * Fork and bmbt are significant parts of the rmap record key, but written
+ * status is merely a record attribute.
+ */
+static inline __be64 ondisk_rec_offset_to_key(const union xfs_btree_rec *rec)
+{
+	return rec->rmap.rm_offset & ~cpu_to_be64(XFS_RMAP_OFF_UNWRITTEN);
+}
+
+STATIC void
+xfs_rtrmapbt_init_key_from_rec(
+	union xfs_btree_key		*key,
+	const union xfs_btree_rec	*rec)
+{
+	key->rmap.rm_startblock = rec->rmap.rm_startblock;
+	key->rmap.rm_owner = rec->rmap.rm_owner;
+	key->rmap.rm_offset = ondisk_rec_offset_to_key(rec);
+}
+
+STATIC void
+xfs_rtrmapbt_init_high_key_from_rec(
+	union xfs_btree_key		*key,
+	const union xfs_btree_rec	*rec)
+{
+	uint64_t			off;
+	int				adj;
+
+	adj = be32_to_cpu(rec->rmap.rm_blockcount) - 1;
+
+	key->rmap.rm_startblock = rec->rmap.rm_startblock;
+	be32_add_cpu(&key->rmap.rm_startblock, adj);
+	key->rmap.rm_owner = rec->rmap.rm_owner;
+	key->rmap.rm_offset = ondisk_rec_offset_to_key(rec);
+	if (XFS_RMAP_NON_INODE_OWNER(be64_to_cpu(rec->rmap.rm_owner)) ||
+	    XFS_RMAP_IS_BMBT_BLOCK(be64_to_cpu(rec->rmap.rm_offset)))
+		return;
+	off = be64_to_cpu(key->rmap.rm_offset);
+	off = (XFS_RMAP_OFF(off) + adj) | (off & ~XFS_RMAP_OFF_MASK);
+	key->rmap.rm_offset = cpu_to_be64(off);
+}
+
+STATIC void
+xfs_rtrmapbt_init_rec_from_cur(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_rec	*rec)
+{
+	rec->rmap.rm_startblock = cpu_to_be32(cur->bc_rec.r.rm_startblock);
+	rec->rmap.rm_blockcount = cpu_to_be32(cur->bc_rec.r.rm_blockcount);
+	rec->rmap.rm_owner = cpu_to_be64(cur->bc_rec.r.rm_owner);
+	rec->rmap.rm_offset = cpu_to_be64(
+			xfs_rmap_irec_offset_pack(&cur->bc_rec.r));
+}
+
+STATIC void
+xfs_rtrmapbt_init_ptr_from_cur(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_ptr	*ptr)
+{
+	ptr->l = 0;
+}
+
+/*
+ * Mask the appropriate parts of the ondisk key field for a key comparison.
+ * Fork and bmbt are significant parts of the rmap record key, but written
+ * status is merely a record attribute.
+ */
+static inline uint64_t offset_keymask(uint64_t offset)
+{
+	return offset & ~XFS_RMAP_OFF_UNWRITTEN;
+}
+
+STATIC int64_t
+xfs_rtrmapbt_key_diff(
+	struct xfs_btree_cur		*cur,
+	const union xfs_btree_key	*key)
+{
+	struct xfs_rmap_irec		*rec = &cur->bc_rec.r;
+	const struct xfs_rmap_key	*kp = &key->rmap;
+	__u64				x, y;
+	int64_t				d;
+
+	d = (int64_t)be32_to_cpu(kp->rm_startblock) - rec->rm_startblock;
+	if (d)
+		return d;
+
+	x = be64_to_cpu(kp->rm_owner);
+	y = rec->rm_owner;
+	if (x > y)
+		return 1;
+	else if (y > x)
+		return -1;
+
+	x = offset_keymask(be64_to_cpu(kp->rm_offset));
+	y = offset_keymask(xfs_rmap_irec_offset_pack(rec));
+	if (x > y)
+		return 1;
+	else if (y > x)
+		return -1;
+	return 0;
+}
+
+STATIC int64_t
+xfs_rtrmapbt_diff_two_keys(
+	struct xfs_btree_cur		*cur,
+	const union xfs_btree_key	*k1,
+	const union xfs_btree_key	*k2,
+	const union xfs_btree_key	*mask)
+{
+	const struct xfs_rmap_key	*kp1 = &k1->rmap;
+	const struct xfs_rmap_key	*kp2 = &k2->rmap;
+	int64_t				d;
+	__u64				x, y;
+
+	/* Doesn't make sense to mask off the physical space part */
+	ASSERT(!mask || mask->rmap.rm_startblock);
+
+	d = (int64_t)be32_to_cpu(kp1->rm_startblock) -
+		     be32_to_cpu(kp2->rm_startblock);
+	if (d)
+		return d;
+
+	if (!mask || mask->rmap.rm_owner) {
+		x = be64_to_cpu(kp1->rm_owner);
+		y = be64_to_cpu(kp2->rm_owner);
+		if (x > y)
+			return 1;
+		else if (y > x)
+			return -1;
+	}
+
+	if (!mask || mask->rmap.rm_offset) {
+		/* Doesn't make sense to allow offset but not owner */
+		ASSERT(!mask || mask->rmap.rm_owner);
+
+		x = offset_keymask(be64_to_cpu(kp1->rm_offset));
+		y = offset_keymask(be64_to_cpu(kp2->rm_offset));
+		if (x > y)
+			return 1;
+		else if (y > x)
+			return -1;
+	}
+
+	return 0;
+}
+
+static xfs_failaddr_t
+xfs_rtrmapbt_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+	xfs_failaddr_t		fa;
+	int			level;
+
+	if (!xfs_verify_magic(bp, block->bb_magic))
+		return __this_address;
+
+	if (!xfs_has_rmapbt(mp))
+		return __this_address;
+	fa = xfs_btree_fsblock_v5hdr_verify(bp, XFS_RMAP_OWN_UNKNOWN);
+	if (fa)
+		return fa;
+	level = be16_to_cpu(block->bb_level);
+	if (level > mp->m_rtrmap_maxlevels)
+		return __this_address;
+
+	return xfs_btree_fsblock_verify(bp, mp->m_rtrmap_mxr[level != 0]);
+}
+
+static void
+xfs_rtrmapbt_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_failaddr_t	fa;
+
+	if (!xfs_btree_fsblock_verify_crc(bp))
+		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
+	else {
+		fa = xfs_rtrmapbt_verify(bp);
+		if (fa)
+			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
+	}
+
+	if (bp->b_error)
+		trace_xfs_btree_corrupt(bp, _RET_IP_);
+}
+
+static void
+xfs_rtrmapbt_write_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_failaddr_t	fa;
+
+	fa = xfs_rtrmapbt_verify(bp);
+	if (fa) {
+		trace_xfs_btree_corrupt(bp, _RET_IP_);
+		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
+		return;
+	}
+	xfs_btree_fsblock_calc_crc(bp);
+
+}
+
+const struct xfs_buf_ops xfs_rtrmapbt_buf_ops = {
+	.name			= "xfs_rtrmapbt",
+	.magic			= { 0, cpu_to_be32(XFS_RTRMAP_CRC_MAGIC) },
+	.verify_read		= xfs_rtrmapbt_read_verify,
+	.verify_write		= xfs_rtrmapbt_write_verify,
+	.verify_struct		= xfs_rtrmapbt_verify,
+};
+
+STATIC int
+xfs_rtrmapbt_keys_inorder(
+	struct xfs_btree_cur		*cur,
+	const union xfs_btree_key	*k1,
+	const union xfs_btree_key	*k2)
+{
+	uint32_t			x;
+	uint32_t			y;
+	uint64_t			a;
+	uint64_t			b;
+
+	x = be32_to_cpu(k1->rmap.rm_startblock);
+	y = be32_to_cpu(k2->rmap.rm_startblock);
+	if (x < y)
+		return 1;
+	else if (x > y)
+		return 0;
+	a = be64_to_cpu(k1->rmap.rm_owner);
+	b = be64_to_cpu(k2->rmap.rm_owner);
+	if (a < b)
+		return 1;
+	else if (a > b)
+		return 0;
+	a = offset_keymask(be64_to_cpu(k1->rmap.rm_offset));
+	b = offset_keymask(be64_to_cpu(k2->rmap.rm_offset));
+	if (a <= b)
+		return 1;
+	return 0;
+}
+
+STATIC int
+xfs_rtrmapbt_recs_inorder(
+	struct xfs_btree_cur		*cur,
+	const union xfs_btree_rec	*r1,
+	const union xfs_btree_rec	*r2)
+{
+	uint32_t			x;
+	uint32_t			y;
+	uint64_t			a;
+	uint64_t			b;
+
+	x = be32_to_cpu(r1->rmap.rm_startblock);
+	y = be32_to_cpu(r2->rmap.rm_startblock);
+	if (x < y)
+		return 1;
+	else if (x > y)
+		return 0;
+	a = be64_to_cpu(r1->rmap.rm_owner);
+	b = be64_to_cpu(r2->rmap.rm_owner);
+	if (a < b)
+		return 1;
+	else if (a > b)
+		return 0;
+	a = offset_keymask(be64_to_cpu(r1->rmap.rm_offset));
+	b = offset_keymask(be64_to_cpu(r2->rmap.rm_offset));
+	if (a <= b)
+		return 1;
+	return 0;
+}
+
+STATIC enum xbtree_key_contig
+xfs_rtrmapbt_keys_contiguous(
+	struct xfs_btree_cur		*cur,
+	const union xfs_btree_key	*key1,
+	const union xfs_btree_key	*key2,
+	const union xfs_btree_key	*mask)
+{
+	ASSERT(!mask || mask->rmap.rm_startblock);
+
+	/*
+	 * We only support checking contiguity of the physical space component.
+	 * If any callers ever need more specificity than that, they'll have to
+	 * implement it here.
+	 */
+	ASSERT(!mask || (!mask->rmap.rm_owner && !mask->rmap.rm_offset));
+
+	return xbtree_key_contig(be32_to_cpu(key1->rmap.rm_startblock),
+				 be32_to_cpu(key2->rmap.rm_startblock));
+}
+
+static inline void
+xfs_rtrmapbt_move_ptrs(
+	struct xfs_mount	*mp,
+	struct xfs_btree_block	*broot,
+	short			old_size,
+	size_t			new_size,
+	unsigned int		numrecs)
+{
+	void			*dptr;
+	void			*sptr;
+
+	sptr = xfs_rtrmap_broot_ptr_addr(mp, broot, 1, old_size);
+	dptr = xfs_rtrmap_broot_ptr_addr(mp, broot, 1, new_size);
+	memmove(dptr, sptr, numrecs * sizeof(xfs_rtrmap_ptr_t));
+}
+
+static struct xfs_btree_block *
+xfs_rtrmapbt_broot_realloc(
+	struct xfs_btree_cur	*cur,
+	unsigned int		new_numrecs)
+{
+	struct xfs_mount	*mp = cur->bc_mp;
+	struct xfs_ifork	*ifp = xfs_btree_ifork_ptr(cur);
+	struct xfs_btree_block	*broot;
+	unsigned int		new_size;
+	unsigned int		old_size = ifp->if_broot_bytes;
+	const unsigned int	level = cur->bc_nlevels - 1;
+
+	new_size = xfs_rtrmap_broot_space_calc(mp, level, new_numrecs);
+
+	/* Handle the nop case quietly. */
+	if (new_size == old_size)
+		return ifp->if_broot;
+
+	if (new_size > old_size) {
+		unsigned int	old_numrecs;
+
+		/*
+		 * If there wasn't any memory allocated before, just allocate
+		 * it now and get out.
+		 */
+		if (old_size == 0)
+			return xfs_broot_realloc(ifp, new_size);
+
+		/*
+		 * If there is already an existing if_broot, then we need to
+		 * realloc it and possibly move the node block pointers because
+		 * those are not butted up against the btree block header.
+		 */
+		old_numrecs = xfs_rtrmapbt_maxrecs(mp, old_size, level == 0);
+		broot = xfs_broot_realloc(ifp, new_size);
+		if (level > 0)
+			xfs_rtrmapbt_move_ptrs(mp, broot, old_size, new_size,
+					old_numrecs);
+		goto out_broot;
+	}
+
+	/*
+	 * We're reducing numrecs.  If we're going all the way to zero, just
+	 * free the block.
+	 */
+	ASSERT(ifp->if_broot != NULL && old_size > 0);
+	if (new_size == 0)
+		return xfs_broot_realloc(ifp, 0);
+
+	/*
+	 * Shrink the btree root by possibly moving the rtrmapbt pointers,
+	 * since they are not butted up against the btree block header.  Then
+	 * reallocate broot.
+	 */
+	if (level > 0)
+		xfs_rtrmapbt_move_ptrs(mp, ifp->if_broot, old_size, new_size,
+				new_numrecs);
+	broot = xfs_broot_realloc(ifp, new_size);
+
+out_broot:
+	ASSERT(xfs_rtrmap_droot_space(broot) <=
+	       xfs_inode_fork_size(cur->bc_ino.ip, cur->bc_ino.whichfork));
+	return broot;
+}
+
+const struct xfs_btree_ops xfs_rtrmapbt_ops = {
+	.name			= "rtrmap",
+	.type			= XFS_BTREE_TYPE_INODE,
+	.geom_flags		= XFS_BTGEO_OVERLAPPING |
+				  XFS_BTGEO_IROOT_RECORDS,
+
+	.rec_len		= sizeof(struct xfs_rmap_rec),
+	/* Overlapping btree; 2 keys per pointer. */
+	.key_len		= 2 * sizeof(struct xfs_rmap_key),
+	.ptr_len		= XFS_BTREE_LONG_PTR_LEN,
+
+	.lru_refs		= XFS_RMAP_BTREE_REF,
+	.statoff		= XFS_STATS_CALC_INDEX(xs_rtrmap_2),
+	.sick_mask		= XFS_SICK_RG_RMAPBT,
+
+	.dup_cursor		= xfs_rtrmapbt_dup_cursor,
+	.alloc_block		= xfs_btree_alloc_metafile_block,
+	.free_block		= xfs_btree_free_metafile_block,
+	.get_minrecs		= xfs_rtrmapbt_get_minrecs,
+	.get_maxrecs		= xfs_rtrmapbt_get_maxrecs,
+	.get_dmaxrecs		= xfs_rtrmapbt_get_dmaxrecs,
+	.init_key_from_rec	= xfs_rtrmapbt_init_key_from_rec,
+	.init_high_key_from_rec	= xfs_rtrmapbt_init_high_key_from_rec,
+	.init_rec_from_cur	= xfs_rtrmapbt_init_rec_from_cur,
+	.init_ptr_from_cur	= xfs_rtrmapbt_init_ptr_from_cur,
+	.key_diff		= xfs_rtrmapbt_key_diff,
+	.buf_ops		= &xfs_rtrmapbt_buf_ops,
+	.diff_two_keys		= xfs_rtrmapbt_diff_two_keys,
+	.keys_inorder		= xfs_rtrmapbt_keys_inorder,
+	.recs_inorder		= xfs_rtrmapbt_recs_inorder,
+	.keys_contiguous	= xfs_rtrmapbt_keys_contiguous,
+	.broot_realloc		= xfs_rtrmapbt_broot_realloc,
+};
+
+/* Allocate a new rt rmap btree cursor. */
+struct xfs_btree_cur *
+xfs_rtrmapbt_init_cursor(
+	struct xfs_trans	*tp,
+	struct xfs_rtgroup	*rtg)
+{
+	struct xfs_inode	*ip = rtg_rmap(rtg);
+	struct xfs_mount	*mp = rtg_mount(rtg);
+	struct xfs_btree_cur	*cur;
+
+	xfs_assert_ilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL);
+
+	cur = xfs_btree_alloc_cursor(mp, tp, &xfs_rtrmapbt_ops,
+			mp->m_rtrmap_maxlevels, xfs_rtrmapbt_cur_cache);
+
+	cur->bc_ino.ip = ip;
+	cur->bc_group = xfs_group_hold(rtg_group(rtg));
+	cur->bc_ino.whichfork = XFS_DATA_FORK;
+	cur->bc_nlevels = be16_to_cpu(ip->i_df.if_broot->bb_level) + 1;
+	cur->bc_ino.forksize = xfs_inode_fork_size(ip, XFS_DATA_FORK);
+
+	return cur;
+}
+
+#ifdef CONFIG_XFS_BTREE_IN_MEM
+/*
+ * Validate an in-memory realtime rmap btree block.  Callers are allowed to
+ * generate an in-memory btree even if the ondisk feature is not enabled.
+ */
+static xfs_failaddr_t
+xfs_rtrmapbt_mem_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = bp->b_mount;
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+	xfs_failaddr_t		fa;
+	unsigned int		level;
+	unsigned int		maxrecs;
+
+	if (!xfs_verify_magic(bp, block->bb_magic))
+		return __this_address;
+
+	fa = xfs_btree_fsblock_v5hdr_verify(bp, XFS_RMAP_OWN_UNKNOWN);
+	if (fa)
+		return fa;
+
+	level = be16_to_cpu(block->bb_level);
+	if (xfs_has_rmapbt(mp)) {
+		if (level >= mp->m_rtrmap_maxlevels)
+			return __this_address;
+	} else {
+		if (level >= xfs_rtrmapbt_maxlevels_ondisk())
+			return __this_address;
+	}
+
+	maxrecs = xfs_rtrmapbt_maxrecs(mp, XFBNO_BLOCKSIZE, level == 0);
+	return xfs_btree_memblock_verify(bp, maxrecs);
+}
+
+static void
+xfs_rtrmapbt_mem_rw_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_failaddr_t	fa = xfs_rtrmapbt_mem_verify(bp);
+
+	if (fa)
+		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
+}
+
+/* skip crc checks on in-memory btrees to save time */
+static const struct xfs_buf_ops xfs_rtrmapbt_mem_buf_ops = {
+	.name			= "xfs_rtrmapbt_mem",
+	.magic			= { 0, cpu_to_be32(XFS_RTRMAP_CRC_MAGIC) },
+	.verify_read		= xfs_rtrmapbt_mem_rw_verify,
+	.verify_write		= xfs_rtrmapbt_mem_rw_verify,
+	.verify_struct		= xfs_rtrmapbt_mem_verify,
+};
+
+const struct xfs_btree_ops xfs_rtrmapbt_mem_ops = {
+	.type			= XFS_BTREE_TYPE_MEM,
+	.geom_flags		= XFS_BTGEO_OVERLAPPING,
+
+	.rec_len		= sizeof(struct xfs_rmap_rec),
+	/* Overlapping btree; 2 keys per pointer. */
+	.key_len		= 2 * sizeof(struct xfs_rmap_key),
+	.ptr_len		= XFS_BTREE_LONG_PTR_LEN,
+
+	.lru_refs		= XFS_RMAP_BTREE_REF,
+	.statoff		= XFS_STATS_CALC_INDEX(xs_rtrmap_mem_2),
+
+	.dup_cursor		= xfbtree_dup_cursor,
+	.set_root		= xfbtree_set_root,
+	.alloc_block		= xfbtree_alloc_block,
+	.free_block		= xfbtree_free_block,
+	.get_minrecs		= xfbtree_get_minrecs,
+	.get_maxrecs		= xfbtree_get_maxrecs,
+	.init_key_from_rec	= xfs_rtrmapbt_init_key_from_rec,
+	.init_high_key_from_rec	= xfs_rtrmapbt_init_high_key_from_rec,
+	.init_rec_from_cur	= xfs_rtrmapbt_init_rec_from_cur,
+	.init_ptr_from_cur	= xfbtree_init_ptr_from_cur,
+	.key_diff		= xfs_rtrmapbt_key_diff,
+	.buf_ops		= &xfs_rtrmapbt_mem_buf_ops,
+	.diff_two_keys		= xfs_rtrmapbt_diff_two_keys,
+	.keys_inorder		= xfs_rtrmapbt_keys_inorder,
+	.recs_inorder		= xfs_rtrmapbt_recs_inorder,
+	.keys_contiguous	= xfs_rtrmapbt_keys_contiguous,
+};
+
+/* Create a cursor for an in-memory btree. */
+struct xfs_btree_cur *
+xfs_rtrmapbt_mem_cursor(
+	struct xfs_rtgroup	*rtg,
+	struct xfs_trans	*tp,
+	struct xfbtree		*xfbt)
+{
+	struct xfs_mount	*mp = rtg_mount(rtg);
+	struct xfs_btree_cur	*cur;
+
+	cur = xfs_btree_alloc_cursor(mp, tp, &xfs_rtrmapbt_mem_ops,
+			mp->m_rtrmap_maxlevels, xfs_rtrmapbt_cur_cache);
+	cur->bc_mem.xfbtree = xfbt;
+	cur->bc_nlevels = xfbt->nlevels;
+	cur->bc_group = xfs_group_hold(rtg_group(rtg));
+	return cur;
+}
+
+/* Create an in-memory realtime rmap btree. */
+int
+xfs_rtrmapbt_mem_init(
+	struct xfs_mount	*mp,
+	struct xfbtree		*xfbt,
+	struct xfs_buftarg	*btp,
+	xfs_rgnumber_t		rgno)
+{
+	xfbt->owner = rgno;
+	return xfbtree_init(mp, xfbt, btp, &xfs_rtrmapbt_mem_ops);
+}
+#endif /* CONFIG_XFS_BTREE_IN_MEM */
+
+/*
+ * Install a new rt reverse mapping btree root.  Caller is responsible for
+ * invalidating and freeing the old btree blocks.
+ */
+void
+xfs_rtrmapbt_commit_staged_btree(
+	struct xfs_btree_cur	*cur,
+	struct xfs_trans	*tp)
+{
+	struct xbtree_ifakeroot	*ifake = cur->bc_ino.ifake;
+	struct xfs_ifork	*ifp;
+	int			flags = XFS_ILOG_CORE | XFS_ILOG_DBROOT;
+
+	ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
+	ASSERT(ifake->if_fork->if_format == XFS_DINODE_FMT_META_BTREE);
+
+	/*
+	 * Free any resources hanging off the real fork, then shallow-copy the
+	 * staging fork's contents into the real fork to transfer everything
+	 * we just built.
+	 */
+	ifp = xfs_ifork_ptr(cur->bc_ino.ip, XFS_DATA_FORK);
+	xfs_idestroy_fork(ifp);
+	memcpy(ifp, ifake->if_fork, sizeof(struct xfs_ifork));
+
+	cur->bc_ino.ip->i_projid = cur->bc_group->xg_gno;
+	xfs_trans_log_inode(tp, cur->bc_ino.ip, flags);
+	xfs_btree_commit_ifakeroot(cur, tp, XFS_DATA_FORK);
+}
+
+/* Calculate number of records in a rt reverse mapping btree block. */
+static inline unsigned int
+xfs_rtrmapbt_block_maxrecs(
+	unsigned int		blocklen,
+	bool			leaf)
+{
+	if (leaf)
+		return blocklen / sizeof(struct xfs_rmap_rec);
+	return blocklen /
+		(2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rtrmap_ptr_t));
+}
+
+/*
+ * Calculate number of records in an rt reverse mapping btree block.
+ */
+unsigned int
+xfs_rtrmapbt_maxrecs(
+	struct xfs_mount	*mp,
+	unsigned int		blocklen,
+	bool			leaf)
+{
+	blocklen -= XFS_RTRMAP_BLOCK_LEN;
+	return xfs_rtrmapbt_block_maxrecs(blocklen, leaf);
+}
+
+/* Compute the max possible height for realtime reverse mapping btrees. */
+unsigned int
+xfs_rtrmapbt_maxlevels_ondisk(void)
+{
+	unsigned long long	max_dblocks;
+	unsigned int		minrecs[2];
+	unsigned int		blocklen;
+
+	blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_LBLOCK_CRC_LEN;
+
+	minrecs[0] = xfs_rtrmapbt_block_maxrecs(blocklen, true) / 2;
+	minrecs[1] = xfs_rtrmapbt_block_maxrecs(blocklen, false) / 2;
+
+	/*
+	 * Compute the asymptotic maxlevels for an rtrmapbt on any rtreflink fs.
+	 *
+	 * On a reflink filesystem, each block in an rtgroup can have up to
+	 * 2^32 (per the refcount record format) owners, which means that
+	 * theoretically we could face up to 2^64 rmap records.  However, we're
+	 * likely to run out of blocks in the data device long before that
+	 * happens, which means that we must compute the max height based on
+	 * what the btree will look like if it consumes almost all the blocks
+	 * in the data device due to maximal sharing factor.
+	 */
+	max_dblocks = -1U; /* max ag count */
+	max_dblocks *= XFS_MAX_CRC_AG_BLOCKS;
+	return xfs_btree_space_to_height(minrecs, max_dblocks);
+}
+
+int __init
+xfs_rtrmapbt_init_cur_cache(void)
+{
+	xfs_rtrmapbt_cur_cache = kmem_cache_create("xfs_rtrmapbt_cur",
+			xfs_btree_cur_sizeof(xfs_rtrmapbt_maxlevels_ondisk()),
+			0, 0, NULL);
+
+	if (!xfs_rtrmapbt_cur_cache)
+		return -ENOMEM;
+	return 0;
+}
+
+void
+xfs_rtrmapbt_destroy_cur_cache(void)
+{
+	kmem_cache_destroy(xfs_rtrmapbt_cur_cache);
+	xfs_rtrmapbt_cur_cache = NULL;
+}
+
+/* Compute the maximum height of an rt reverse mapping btree. */
+void
+xfs_rtrmapbt_compute_maxlevels(
+	struct xfs_mount	*mp)
+{
+	unsigned int		d_maxlevels, r_maxlevels;
+
+	if (!xfs_has_rtrmapbt(mp)) {
+		mp->m_rtrmap_maxlevels = 0;
+		return;
+	}
+
+	/*
+	 * The realtime rmapbt lives on the data device, which means that its
+	 * maximum height is constrained by the size of the data device and
+	 * the height required to store one rmap record for each block in an
+	 * rt group.
+	 *
+	 * On a reflink filesystem, each rt block can have up to 2^32 (per the
+	 * refcount record format) owners, which means that theoretically we
+	 * could face up to 2^64 rmap records.  This makes the computation of
+	 * maxlevels based on record count meaningless, so we only consider the
+	 * size of the data device.
+	 */
+	d_maxlevels = xfs_btree_space_to_height(mp->m_rtrmap_mnr,
+				mp->m_sb.sb_dblocks);
+	if (xfs_has_rtreflink(mp)) {
+		mp->m_rtrmap_maxlevels = d_maxlevels + 1;
+		return;
+	}
+
+	r_maxlevels = xfs_btree_compute_maxlevels(mp->m_rtrmap_mnr,
+				mp->m_groups[XG_TYPE_RTG].blocks);
+
+	/* Add one level to handle the inode root level. */
+	mp->m_rtrmap_maxlevels = min(d_maxlevels, r_maxlevels) + 1;
+}
+
+/* Calculate the rtrmap btree size for some records. */
+unsigned long long
+xfs_rtrmapbt_calc_size(
+	struct xfs_mount	*mp,
+	unsigned long long	len)
+{
+	return xfs_btree_calc_size(mp->m_rtrmap_mnr, len);
+}
+
+/*
+ * Calculate the maximum rmap btree size.
+ */
+static unsigned long long
+xfs_rtrmapbt_max_size(
+	struct xfs_mount	*mp,
+	xfs_rtblock_t		rtblocks)
+{
+	/* Bail out if we're uninitialized, which can happen in mkfs. */
+	if (mp->m_rtrmap_mxr[0] == 0)
+		return 0;
+
+	return xfs_rtrmapbt_calc_size(mp, rtblocks);
+}
+
+/*
+ * Figure out how many blocks to reserve and how many are used by this btree.
+ */
+xfs_filblks_t
+xfs_rtrmapbt_calc_reserves(
+	struct xfs_mount	*mp)
+{
+	uint32_t		blocks = mp->m_groups[XG_TYPE_RTG].blocks;
+
+	if (!xfs_has_rtrmapbt(mp))
+		return 0;
+
+	/* Reserve 1% of the rtgroup or enough for 1 block per record. */
+	return max_t(xfs_filblks_t, blocks / 100,
+			xfs_rtrmapbt_max_size(mp, blocks));
+}
+
+/* Convert on-disk form of btree root to in-memory form. */
+STATIC void
+xfs_rtrmapbt_from_disk(
+	struct xfs_inode	*ip,
+	struct xfs_rtrmap_root	*dblock,
+	unsigned int		dblocklen,
+	struct xfs_btree_block	*rblock)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_rmap_key	*fkp;
+	__be64			*fpp;
+	struct xfs_rmap_key	*tkp;
+	__be64			*tpp;
+	struct xfs_rmap_rec	*frp;
+	struct xfs_rmap_rec	*trp;
+	unsigned int		rblocklen = xfs_rtrmap_broot_space(mp, dblock);
+	unsigned int		numrecs;
+	unsigned int		maxrecs;
+
+	xfs_btree_init_block(mp, rblock, &xfs_rtrmapbt_ops, 0, 0, ip->i_ino);
+
+	rblock->bb_level = dblock->bb_level;
+	rblock->bb_numrecs = dblock->bb_numrecs;
+	numrecs = be16_to_cpu(dblock->bb_numrecs);
+
+	if (be16_to_cpu(rblock->bb_level) > 0) {
+		maxrecs = xfs_rtrmapbt_droot_maxrecs(dblocklen, false);
+		fkp = xfs_rtrmap_droot_key_addr(dblock, 1);
+		tkp = xfs_rtrmap_key_addr(rblock, 1);
+		fpp = xfs_rtrmap_droot_ptr_addr(dblock, 1, maxrecs);
+		tpp = xfs_rtrmap_broot_ptr_addr(mp, rblock, 1, rblocklen);
+		memcpy(tkp, fkp, 2 * sizeof(*fkp) * numrecs);
+		memcpy(tpp, fpp, sizeof(*fpp) * numrecs);
+	} else {
+		frp = xfs_rtrmap_droot_rec_addr(dblock, 1);
+		trp = xfs_rtrmap_rec_addr(rblock, 1);
+		memcpy(trp, frp, sizeof(*frp) * numrecs);
+	}
+}
+
+/* Load a realtime reverse mapping btree root in from disk. */
+int
+xfs_iformat_rtrmap(
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*dip)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_rtrmap_root	*dfp = XFS_DFORK_PTR(dip, XFS_DATA_FORK);
+	struct xfs_btree_block	*broot;
+	unsigned int		numrecs;
+	unsigned int		level;
+	int			dsize;
+
+	/*
+	 * growfs must create the rtrmap inodes before adding a realtime volume
+	 * to the filesystem, so we cannot use the rtrmapbt predicate here.
+	 */
+	if (!xfs_has_rmapbt(ip->i_mount)) {
+		xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
+		return -EFSCORRUPTED;
+	}
+
+	dsize = XFS_DFORK_SIZE(dip, mp, XFS_DATA_FORK);
+	numrecs = be16_to_cpu(dfp->bb_numrecs);
+	level = be16_to_cpu(dfp->bb_level);
+
+	if (level > mp->m_rtrmap_maxlevels ||
+	    xfs_rtrmap_droot_space_calc(level, numrecs) > dsize) {
+		xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
+		return -EFSCORRUPTED;
+	}
+
+	broot = xfs_broot_alloc(xfs_ifork_ptr(ip, XFS_DATA_FORK),
+			xfs_rtrmap_broot_space_calc(mp, level, numrecs));
+	if (broot)
+		xfs_rtrmapbt_from_disk(ip, dfp, dsize, broot);
+	return 0;
+}
+
+/* Convert in-memory form of btree root to on-disk form. */
+void
+xfs_rtrmapbt_to_disk(
+	struct xfs_mount	*mp,
+	struct xfs_btree_block	*rblock,
+	unsigned int		rblocklen,
+	struct xfs_rtrmap_root	*dblock,
+	unsigned int		dblocklen)
+{
+	struct xfs_rmap_key	*fkp;
+	__be64			*fpp;
+	struct xfs_rmap_key	*tkp;
+	__be64			*tpp;
+	struct xfs_rmap_rec	*frp;
+	struct xfs_rmap_rec	*trp;
+	unsigned int		numrecs;
+	unsigned int		maxrecs;
+
+	ASSERT(rblock->bb_magic == cpu_to_be32(XFS_RTRMAP_CRC_MAGIC));
+	ASSERT(uuid_equal(&rblock->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid));
+	ASSERT(rblock->bb_u.l.bb_blkno == cpu_to_be64(XFS_BUF_DADDR_NULL));
+	ASSERT(rblock->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK));
+	ASSERT(rblock->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK));
+
+	dblock->bb_level = rblock->bb_level;
+	dblock->bb_numrecs = rblock->bb_numrecs;
+	numrecs = be16_to_cpu(rblock->bb_numrecs);
+
+	if (be16_to_cpu(rblock->bb_level) > 0) {
+		maxrecs = xfs_rtrmapbt_droot_maxrecs(dblocklen, false);
+		fkp = xfs_rtrmap_key_addr(rblock, 1);
+		tkp = xfs_rtrmap_droot_key_addr(dblock, 1);
+		fpp = xfs_rtrmap_broot_ptr_addr(mp, rblock, 1, rblocklen);
+		tpp = xfs_rtrmap_droot_ptr_addr(dblock, 1, maxrecs);
+		memcpy(tkp, fkp, 2 * sizeof(*fkp) * numrecs);
+		memcpy(tpp, fpp, sizeof(*fpp) * numrecs);
+	} else {
+		frp = xfs_rtrmap_rec_addr(rblock, 1);
+		trp = xfs_rtrmap_droot_rec_addr(dblock, 1);
+		memcpy(trp, frp, sizeof(*frp) * numrecs);
+	}
+}
+
+/* Flush a realtime reverse mapping btree root out to disk. */
+void
+xfs_iflush_rtrmap(
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*dip)
+{
+	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
+	struct xfs_rtrmap_root	*dfp = XFS_DFORK_PTR(dip, XFS_DATA_FORK);
+
+	ASSERT(ifp->if_broot != NULL);
+	ASSERT(ifp->if_broot_bytes > 0);
+	ASSERT(xfs_rtrmap_droot_space(ifp->if_broot) <=
+			xfs_inode_fork_size(ip, XFS_DATA_FORK));
+	xfs_rtrmapbt_to_disk(ip->i_mount, ifp->if_broot, ifp->if_broot_bytes,
+			dfp, XFS_DFORK_SIZE(dip, ip->i_mount, XFS_DATA_FORK));
+}
+
+/*
+ * Create a realtime rmap btree inode.
+ */
+int
+xfs_rtrmapbt_create(
+	struct xfs_rtgroup	*rtg,
+	struct xfs_inode	*ip,
+	struct xfs_trans	*tp,
+	bool			init)
+{
+	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_btree_block	*broot;
+
+	ifp->if_format = XFS_DINODE_FMT_META_BTREE;
+	ASSERT(ifp->if_broot_bytes == 0);
+	ASSERT(ifp->if_bytes == 0);
+
+	/* Initialize the empty incore btree root. */
+	broot = xfs_broot_realloc(ifp, xfs_rtrmap_broot_space_calc(mp, 0, 0));
+	if (broot)
+		xfs_btree_init_block(mp, broot, &xfs_rtrmapbt_ops, 0, 0,
+				ip->i_ino);
+	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE | XFS_ILOG_DBROOT);
+
+	return 0;
+}
+
+/*
+ * Initialize an rmap for a realtime superblock using the potentially updated
+ * rt geometry in the provided @mp.
+ */
+int
+xfs_rtrmapbt_init_rtsb(
+	struct xfs_mount	*mp,
+	struct xfs_rtgroup	*rtg,
+	struct xfs_trans	*tp)
+{
+	struct xfs_rmap_irec	rmap = {
+		.rm_blockcount	= mp->m_sb.sb_rextsize,
+		.rm_owner	= XFS_RMAP_OWN_FS,
+	};
+	struct xfs_btree_cur	*cur;
+	int			error;
+
+	ASSERT(xfs_has_rtsb(mp));
+	ASSERT(rtg_rgno(rtg) == 0);
+
+	cur = xfs_rtrmapbt_init_cursor(tp, rtg);
+	error = xfs_rmap_map_raw(cur, &rmap);
+	xfs_btree_del_cursor(cur, error);
+	return error;
+}