1/*
   2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#include "xfs.h"
  19#include "xfs_fs.h"
  20#include "xfs_types.h"
  21#include "xfs_bit.h"
  22#include "xfs_log.h"
  23#include "xfs_inum.h"
  24#include "xfs_trans.h"
  25#include "xfs_sb.h"
  26#include "xfs_ag.h"
  27#include "xfs_mount.h"
  28#include "xfs_bmap_btree.h"
  29#include "xfs_alloc_btree.h"
  30#include "xfs_ialloc_btree.h"
  31#include "xfs_dinode.h"
  32#include "xfs_inode.h"
  33#include "xfs_inode_item.h"
  34#include "xfs_btree.h"
  35#include "xfs_error.h"
  36#include "xfs_trace.h"
  37
  38/*
  39 * Cursor allocation zone.
  40 */
  41kmem_zone_t	*xfs_btree_cur_zone;
  42
  43/*
  44 * Btree magic numbers.
  45 */
  46const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
  47	XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
  48};
  49
  50
  51STATIC int				/* error (0 or EFSCORRUPTED) */
  52xfs_btree_check_lblock(
  53	struct xfs_btree_cur	*cur,	/* btree cursor */
  54	struct xfs_btree_block	*block,	/* btree long form block pointer */
  55	int			level,	/* level of the btree block */
  56	struct xfs_buf		*bp)	/* buffer for block, if any */
  57{
  58	int			lblock_ok; /* block passes checks */
  59	struct xfs_mount	*mp;	/* file system mount point */
  60
  61	mp = cur->bc_mp;
  62	lblock_ok =
  63		be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
  64		be16_to_cpu(block->bb_level) == level &&
  65		be16_to_cpu(block->bb_numrecs) <=
  66			cur->bc_ops->get_maxrecs(cur, level) &&
  67		block->bb_u.l.bb_leftsib &&
  68		(block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
  69		 XFS_FSB_SANITY_CHECK(mp,
  70		 	be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
  71		block->bb_u.l.bb_rightsib &&
  72		(block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) ||
  73		 XFS_FSB_SANITY_CHECK(mp,
  74		 	be64_to_cpu(block->bb_u.l.bb_rightsib)));
  75	if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
  76			XFS_ERRTAG_BTREE_CHECK_LBLOCK,
  77			XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
  78		if (bp)
  79			trace_xfs_btree_corrupt(bp, _RET_IP_);
  80		XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
  81				 mp);
  82		return XFS_ERROR(EFSCORRUPTED);
  83	}
  84	return 0;
  85}
  86
  87STATIC int				/* error (0 or EFSCORRUPTED) */
  88xfs_btree_check_sblock(
  89	struct xfs_btree_cur	*cur,	/* btree cursor */
  90	struct xfs_btree_block	*block,	/* btree short form block pointer */
  91	int			level,	/* level of the btree block */
  92	struct xfs_buf		*bp)	/* buffer containing block */
  93{
  94	struct xfs_buf		*agbp;	/* buffer for ag. freespace struct */
  95	struct xfs_agf		*agf;	/* ag. freespace structure */
  96	xfs_agblock_t		agflen;	/* native ag. freespace length */
  97	int			sblock_ok; /* block passes checks */
  98
  99	agbp = cur->bc_private.a.agbp;
 100	agf = XFS_BUF_TO_AGF(agbp);
 101	agflen = be32_to_cpu(agf->agf_length);
 102	sblock_ok =
 103		be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
 104		be16_to_cpu(block->bb_level) == level &&
 105		be16_to_cpu(block->bb_numrecs) <=
 106			cur->bc_ops->get_maxrecs(cur, level) &&
 107		(block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
 108		 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
 109		block->bb_u.s.bb_leftsib &&
 110		(block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
 111		 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
 112		block->bb_u.s.bb_rightsib;
 113	if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
 114			XFS_ERRTAG_BTREE_CHECK_SBLOCK,
 115			XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
 116		if (bp)
 117			trace_xfs_btree_corrupt(bp, _RET_IP_);
 118		XFS_CORRUPTION_ERROR("xfs_btree_check_sblock",
 119			XFS_ERRLEVEL_LOW, cur->bc_mp, block);
 120		return XFS_ERROR(EFSCORRUPTED);
 121	}
 122	return 0;
 123}
 124
 125/*
 126 * Debug routine: check that block header is ok.
 127 */
 128int
 129xfs_btree_check_block(
 130	struct xfs_btree_cur	*cur,	/* btree cursor */
 131	struct xfs_btree_block	*block,	/* generic btree block pointer */
 132	int			level,	/* level of the btree block */
 133	struct xfs_buf		*bp)	/* buffer containing block, if any */
 134{
 135	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 136		return xfs_btree_check_lblock(cur, block, level, bp);
 137	else
 138		return xfs_btree_check_sblock(cur, block, level, bp);
 139}
 140
 141/*
 142 * Check that (long) pointer is ok.
 143 */
 144int					/* error (0 or EFSCORRUPTED) */
 145xfs_btree_check_lptr(
 146	struct xfs_btree_cur	*cur,	/* btree cursor */
 147	xfs_dfsbno_t		bno,	/* btree block disk address */
 148	int			level)	/* btree block level */
 149{
 150	XFS_WANT_CORRUPTED_RETURN(
 151		level > 0 &&
 152		bno != NULLDFSBNO &&
 153		XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
 154	return 0;
 155}
 156
 157#ifdef DEBUG
 158/*
 159 * Check that (short) pointer is ok.
 160 */
 161STATIC int				/* error (0 or EFSCORRUPTED) */
 162xfs_btree_check_sptr(
 163	struct xfs_btree_cur	*cur,	/* btree cursor */
 164	xfs_agblock_t		bno,	/* btree block disk address */
 165	int			level)	/* btree block level */
 166{
 167	xfs_agblock_t		agblocks = cur->bc_mp->m_sb.sb_agblocks;
 168
 169	XFS_WANT_CORRUPTED_RETURN(
 170		level > 0 &&
 171		bno != NULLAGBLOCK &&
 172		bno != 0 &&
 173		bno < agblocks);
 174	return 0;
 175}
 176
 177/*
 178 * Check that block ptr is ok.
 179 */
 180STATIC int				/* error (0 or EFSCORRUPTED) */
 181xfs_btree_check_ptr(
 182	struct xfs_btree_cur	*cur,	/* btree cursor */
 183	union xfs_btree_ptr	*ptr,	/* btree block disk address */
 184	int			index,	/* offset from ptr to check */
 185	int			level)	/* btree block level */
 186{
 187	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 188		return xfs_btree_check_lptr(cur,
 189				be64_to_cpu((&ptr->l)[index]), level);
 190	} else {
 191		return xfs_btree_check_sptr(cur,
 192				be32_to_cpu((&ptr->s)[index]), level);
 193	}
 194}
 195#endif
 196
 197/*
 198 * Delete the btree cursor.
 199 */
 200void
 201xfs_btree_del_cursor(
 202	xfs_btree_cur_t	*cur,		/* btree cursor */
 203	int		error)		/* del because of error */
 204{
 205	int		i;		/* btree level */
 206
 207	/*
 208	 * Clear the buffer pointers, and release the buffers.
 209	 * If we're doing this in the face of an error, we
 210	 * need to make sure to inspect all of the entries
 211	 * in the bc_bufs array for buffers to be unlocked.
 212	 * This is because some of the btree code works from
 213	 * level n down to 0, and if we get an error along
 214	 * the way we won't have initialized all the entries
 215	 * down to 0.
 216	 */
 217	for (i = 0; i < cur->bc_nlevels; i++) {
 218		if (cur->bc_bufs[i])
 219			xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
 220		else if (!error)
 221			break;
 222	}
 223	/*
 224	 * Can't free a bmap cursor without having dealt with the
 225	 * allocated indirect blocks' accounting.
 226	 */
 227	ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
 228	       cur->bc_private.b.allocated == 0);
 229	/*
 230	 * Free the cursor.
 231	 */
 232	kmem_zone_free(xfs_btree_cur_zone, cur);
 233}
 234
 235/*
 236 * Duplicate the btree cursor.
 237 * Allocate a new one, copy the record, re-get the buffers.
 238 */
 239int					/* error */
 240xfs_btree_dup_cursor(
 241	xfs_btree_cur_t	*cur,		/* input cursor */
 242	xfs_btree_cur_t	**ncur)		/* output cursor */
 243{
 244	xfs_buf_t	*bp;		/* btree block's buffer pointer */
 245	int		error;		/* error return value */
 246	int		i;		/* level number of btree block */
 247	xfs_mount_t	*mp;		/* mount structure for filesystem */
 248	xfs_btree_cur_t	*new;		/* new cursor value */
 249	xfs_trans_t	*tp;		/* transaction pointer, can be NULL */
 250
 251	tp = cur->bc_tp;
 252	mp = cur->bc_mp;
 253
 254	/*
 255	 * Allocate a new cursor like the old one.
 256	 */
 257	new = cur->bc_ops->dup_cursor(cur);
 258
 259	/*
 260	 * Copy the record currently in the cursor.
 261	 */
 262	new->bc_rec = cur->bc_rec;
 263
 264	/*
 265	 * For each level current, re-get the buffer and copy the ptr value.
 266	 */
 267	for (i = 0; i < new->bc_nlevels; i++) {
 268		new->bc_ptrs[i] = cur->bc_ptrs[i];
 269		new->bc_ra[i] = cur->bc_ra[i];
 270		if ((bp = cur->bc_bufs[i])) {
 271			if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 272				XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
 273				xfs_btree_del_cursor(new, error);
 274				*ncur = NULL;
 275				return error;
 276			}
 277			new->bc_bufs[i] = bp;
 278			ASSERT(!xfs_buf_geterror(bp));
 279		} else
 280			new->bc_bufs[i] = NULL;
 281	}
 282	*ncur = new;
 283	return 0;
 284}
 285
 286/*
 287 * XFS btree block layout and addressing:
 288 *
 289 * There are two types of blocks in the btree: leaf and non-leaf blocks.
 290 *
 291 * The leaf record start with a header then followed by records containing
 292 * the values.  A non-leaf block also starts with the same header, and
 293 * then first contains lookup keys followed by an equal number of pointers
 294 * to the btree blocks at the previous level.
 295 *
 296 *		+--------+-------+-------+-------+-------+-------+-------+
 297 * Leaf:	| header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
 298 *		+--------+-------+-------+-------+-------+-------+-------+
 299 *
 300 *		+--------+-------+-------+-------+-------+-------+-------+
 301 * Non-Leaf:	| header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
 302 *		+--------+-------+-------+-------+-------+-------+-------+
 303 *
 304 * The header is called struct xfs_btree_block for reasons better left unknown
 305 * and comes in different versions for short (32bit) and long (64bit) block
 306 * pointers.  The record and key structures are defined by the btree instances
 307 * and opaque to the btree core.  The block pointers are simple disk endian
 308 * integers, available in a short (32bit) and long (64bit) variant.
 309 *
 310 * The helpers below calculate the offset of a given record, key or pointer
 311 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
 312 * record, key or pointer (xfs_btree_*_addr).  Note that all addressing
 313 * inside the btree block is done using indices starting at one, not zero!
 314 */
 315
 316/*
 317 * Return size of the btree block header for this btree instance.
 318 */
 319static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
 320{
 321	return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
 322		XFS_BTREE_LBLOCK_LEN :
 323		XFS_BTREE_SBLOCK_LEN;
 324}
 325
 326/*
 327 * Return size of btree block pointers for this btree instance.
 328 */
 329static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
 330{
 331	return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
 332		sizeof(__be64) : sizeof(__be32);
 333}
 334
 335/*
 336 * Calculate offset of the n-th record in a btree block.
 337 */
 338STATIC size_t
 339xfs_btree_rec_offset(
 340	struct xfs_btree_cur	*cur,
 341	int			n)
 342{
 343	return xfs_btree_block_len(cur) +
 344		(n - 1) * cur->bc_ops->rec_len;
 345}
 346
 347/*
 348 * Calculate offset of the n-th key in a btree block.
 349 */
 350STATIC size_t
 351xfs_btree_key_offset(
 352	struct xfs_btree_cur	*cur,
 353	int			n)
 354{
 355	return xfs_btree_block_len(cur) +
 356		(n - 1) * cur->bc_ops->key_len;
 357}
 358
 359/*
 360 * Calculate offset of the n-th block pointer in a btree block.
 361 */
 362STATIC size_t
 363xfs_btree_ptr_offset(
 364	struct xfs_btree_cur	*cur,
 365	int			n,
 366	int			level)
 367{
 368	return xfs_btree_block_len(cur) +
 369		cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
 370		(n - 1) * xfs_btree_ptr_len(cur);
 371}
 372
 373/*
 374 * Return a pointer to the n-th record in the btree block.
 375 */
 376STATIC union xfs_btree_rec *
 377xfs_btree_rec_addr(
 378	struct xfs_btree_cur	*cur,
 379	int			n,
 380	struct xfs_btree_block	*block)
 381{
 382	return (union xfs_btree_rec *)
 383		((char *)block + xfs_btree_rec_offset(cur, n));
 384}
 385
 386/*
 387 * Return a pointer to the n-th key in the btree block.
 388 */
 389STATIC union xfs_btree_key *
 390xfs_btree_key_addr(
 391	struct xfs_btree_cur	*cur,
 392	int			n,
 393	struct xfs_btree_block	*block)
 394{
 395	return (union xfs_btree_key *)
 396		((char *)block + xfs_btree_key_offset(cur, n));
 397}
 398
 399/*
 400 * Return a pointer to the n-th block pointer in the btree block.
 401 */
 402STATIC union xfs_btree_ptr *
 403xfs_btree_ptr_addr(
 404	struct xfs_btree_cur	*cur,
 405	int			n,
 406	struct xfs_btree_block	*block)
 407{
 408	int			level = xfs_btree_get_level(block);
 409
 410	ASSERT(block->bb_level != 0);
 411
 412	return (union xfs_btree_ptr *)
 413		((char *)block + xfs_btree_ptr_offset(cur, n, level));
 414}
 415
 416/*
 417 * Get a the root block which is stored in the inode.
 418 *
 419 * For now this btree implementation assumes the btree root is always
 420 * stored in the if_broot field of an inode fork.
 421 */
 422STATIC struct xfs_btree_block *
 423xfs_btree_get_iroot(
 424       struct xfs_btree_cur    *cur)
 425{
 426       struct xfs_ifork        *ifp;
 427
 428       ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
 429       return (struct xfs_btree_block *)ifp->if_broot;
 430}
 431
 432/*
 433 * Retrieve the block pointer from the cursor at the given level.
 434 * This may be an inode btree root or from a buffer.
 435 */
 436STATIC struct xfs_btree_block *		/* generic btree block pointer */
 437xfs_btree_get_block(
 438	struct xfs_btree_cur	*cur,	/* btree cursor */
 439	int			level,	/* level in btree */
 440	struct xfs_buf		**bpp)	/* buffer containing the block */
 441{
 442	if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
 443	    (level == cur->bc_nlevels - 1)) {
 444		*bpp = NULL;
 445		return xfs_btree_get_iroot(cur);
 446	}
 447
 448	*bpp = cur->bc_bufs[level];
 449	return XFS_BUF_TO_BLOCK(*bpp);
 450}
 451
 452/*
 453 * Get a buffer for the block, return it with no data read.
 454 * Long-form addressing.
 455 */
 456xfs_buf_t *				/* buffer for fsbno */
 457xfs_btree_get_bufl(
 458	xfs_mount_t	*mp,		/* file system mount point */
 459	xfs_trans_t	*tp,		/* transaction pointer */
 460	xfs_fsblock_t	fsbno,		/* file system block number */
 461	uint		lock)		/* lock flags for get_buf */
 462{
 463	xfs_buf_t	*bp;		/* buffer pointer (return value) */
 464	xfs_daddr_t		d;		/* real disk block address */
 465
 466	ASSERT(fsbno != NULLFSBLOCK);
 467	d = XFS_FSB_TO_DADDR(mp, fsbno);
 468	bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
 469	ASSERT(!xfs_buf_geterror(bp));
 470	return bp;
 471}
 472
 473/*
 474 * Get a buffer for the block, return it with no data read.
 475 * Short-form addressing.
 476 */
 477xfs_buf_t *				/* buffer for agno/agbno */
 478xfs_btree_get_bufs(
 479	xfs_mount_t	*mp,		/* file system mount point */
 480	xfs_trans_t	*tp,		/* transaction pointer */
 481	xfs_agnumber_t	agno,		/* allocation group number */
 482	xfs_agblock_t	agbno,		/* allocation group block number */
 483	uint		lock)		/* lock flags for get_buf */
 484{
 485	xfs_buf_t	*bp;		/* buffer pointer (return value) */
 486	xfs_daddr_t		d;		/* real disk block address */
 487
 488	ASSERT(agno != NULLAGNUMBER);
 489	ASSERT(agbno != NULLAGBLOCK);
 490	d = XFS_AGB_TO_DADDR(mp, agno, agbno);
 491	bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
 492	ASSERT(!xfs_buf_geterror(bp));
 493	return bp;
 494}
 495
 496/*
 497 * Check for the cursor referring to the last block at the given level.
 498 */
 499int					/* 1=is last block, 0=not last block */
 500xfs_btree_islastblock(
 501	xfs_btree_cur_t		*cur,	/* btree cursor */
 502	int			level)	/* level to check */
 503{
 504	struct xfs_btree_block	*block;	/* generic btree block pointer */
 505	xfs_buf_t		*bp;	/* buffer containing block */
 506
 507	block = xfs_btree_get_block(cur, level, &bp);
 508	xfs_btree_check_block(cur, block, level, bp);
 509	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 510		return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO);
 511	else
 512		return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
 513}
 514
 515/*
 516 * Change the cursor to point to the first record at the given level.
 517 * Other levels are unaffected.
 518 */
 519STATIC int				/* success=1, failure=0 */
 520xfs_btree_firstrec(
 521	xfs_btree_cur_t		*cur,	/* btree cursor */
 522	int			level)	/* level to change */
 523{
 524	struct xfs_btree_block	*block;	/* generic btree block pointer */
 525	xfs_buf_t		*bp;	/* buffer containing block */
 526
 527	/*
 528	 * Get the block pointer for this level.
 529	 */
 530	block = xfs_btree_get_block(cur, level, &bp);
 531	xfs_btree_check_block(cur, block, level, bp);
 532	/*
 533	 * It's empty, there is no such record.
 534	 */
 535	if (!block->bb_numrecs)
 536		return 0;
 537	/*
 538	 * Set the ptr value to 1, that's the first record/key.
 539	 */
 540	cur->bc_ptrs[level] = 1;
 541	return 1;
 542}
 543
 544/*
 545 * Change the cursor to point to the last record in the current block
 546 * at the given level.  Other levels are unaffected.
 547 */
 548STATIC int				/* success=1, failure=0 */
 549xfs_btree_lastrec(
 550	xfs_btree_cur_t		*cur,	/* btree cursor */
 551	int			level)	/* level to change */
 552{
 553	struct xfs_btree_block	*block;	/* generic btree block pointer */
 554	xfs_buf_t		*bp;	/* buffer containing block */
 555
 556	/*
 557	 * Get the block pointer for this level.
 558	 */
 559	block = xfs_btree_get_block(cur, level, &bp);
 560	xfs_btree_check_block(cur, block, level, bp);
 561	/*
 562	 * It's empty, there is no such record.
 563	 */
 564	if (!block->bb_numrecs)
 565		return 0;
 566	/*
 567	 * Set the ptr value to numrecs, that's the last record/key.
 568	 */
 569	cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
 570	return 1;
 571}
 572
 573/*
 574 * Compute first and last byte offsets for the fields given.
 575 * Interprets the offsets table, which contains struct field offsets.
 576 */
 577void
 578xfs_btree_offsets(
 579	__int64_t	fields,		/* bitmask of fields */
 580	const short	*offsets,	/* table of field offsets */
 581	int		nbits,		/* number of bits to inspect */
 582	int		*first,		/* output: first byte offset */
 583	int		*last)		/* output: last byte offset */
 584{
 585	int		i;		/* current bit number */
 586	__int64_t	imask;		/* mask for current bit number */
 587
 588	ASSERT(fields != 0);
 589	/*
 590	 * Find the lowest bit, so the first byte offset.
 591	 */
 592	for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
 593		if (imask & fields) {
 594			*first = offsets[i];
 595			break;
 596		}
 597	}
 598	/*
 599	 * Find the highest bit, so the last byte offset.
 600	 */
 601	for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
 602		if (imask & fields) {
 603			*last = offsets[i + 1] - 1;
 604			break;
 605		}
 606	}
 607}
 608
 609/*
 610 * Get a buffer for the block, return it read in.
 611 * Long-form addressing.
 612 */
 613int					/* error */
 614xfs_btree_read_bufl(
 615	xfs_mount_t	*mp,		/* file system mount point */
 616	xfs_trans_t	*tp,		/* transaction pointer */
 617	xfs_fsblock_t	fsbno,		/* file system block number */
 618	uint		lock,		/* lock flags for read_buf */
 619	xfs_buf_t	**bpp,		/* buffer for fsbno */
 620	int		refval)		/* ref count value for buffer */
 621{
 622	xfs_buf_t	*bp;		/* return value */
 623	xfs_daddr_t		d;		/* real disk block address */
 624	int		error;
 625
 626	ASSERT(fsbno != NULLFSBLOCK);
 627	d = XFS_FSB_TO_DADDR(mp, fsbno);
 628	if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
 629			mp->m_bsize, lock, &bp))) {
 630		return error;
 631	}
 632	ASSERT(!xfs_buf_geterror(bp));
 633	if (bp)
 634		XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
 635	*bpp = bp;
 636	return 0;
 637}
 638
 639/*
 640 * Read-ahead the block, don't wait for it, don't return a buffer.
 641 * Long-form addressing.
 642 */
 643/* ARGSUSED */
 644void
 645xfs_btree_reada_bufl(
 646	xfs_mount_t	*mp,		/* file system mount point */
 647	xfs_fsblock_t	fsbno,		/* file system block number */
 648	xfs_extlen_t	count)		/* count of filesystem blocks */
 649{
 650	xfs_daddr_t		d;
 651
 652	ASSERT(fsbno != NULLFSBLOCK);
 653	d = XFS_FSB_TO_DADDR(mp, fsbno);
 654	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
 655}
 656
 657/*
 658 * Read-ahead the block, don't wait for it, don't return a buffer.
 659 * Short-form addressing.
 660 */
 661/* ARGSUSED */
 662void
 663xfs_btree_reada_bufs(
 664	xfs_mount_t	*mp,		/* file system mount point */
 665	xfs_agnumber_t	agno,		/* allocation group number */
 666	xfs_agblock_t	agbno,		/* allocation group block number */
 667	xfs_extlen_t	count)		/* count of filesystem blocks */
 668{
 669	xfs_daddr_t		d;
 670
 671	ASSERT(agno != NULLAGNUMBER);
 672	ASSERT(agbno != NULLAGBLOCK);
 673	d = XFS_AGB_TO_DADDR(mp, agno, agbno);
 674	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
 675}
 676
 677STATIC int
 678xfs_btree_readahead_lblock(
 679	struct xfs_btree_cur	*cur,
 680	int			lr,
 681	struct xfs_btree_block	*block)
 682{
 683	int			rval = 0;
 684	xfs_dfsbno_t		left = be64_to_cpu(block->bb_u.l.bb_leftsib);
 685	xfs_dfsbno_t		right = be64_to_cpu(block->bb_u.l.bb_rightsib);
 686
 687	if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
 688		xfs_btree_reada_bufl(cur->bc_mp, left, 1);
 689		rval++;
 690	}
 691
 692	if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
 693		xfs_btree_reada_bufl(cur->bc_mp, right, 1);
 694		rval++;
 695	}
 696
 697	return rval;
 698}
 699
 700STATIC int
 701xfs_btree_readahead_sblock(
 702	struct xfs_btree_cur	*cur,
 703	int			lr,
 704	struct xfs_btree_block *block)
 705{
 706	int			rval = 0;
 707	xfs_agblock_t		left = be32_to_cpu(block->bb_u.s.bb_leftsib);
 708	xfs_agblock_t		right = be32_to_cpu(block->bb_u.s.bb_rightsib);
 709
 710
 711	if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
 712		xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
 713				     left, 1);
 714		rval++;
 715	}
 716
 717	if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
 718		xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
 719				     right, 1);
 720		rval++;
 721	}
 722
 723	return rval;
 724}
 725
 726/*
 727 * Read-ahead btree blocks, at the given level.
 728 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
 729 */
 730STATIC int
 731xfs_btree_readahead(
 732	struct xfs_btree_cur	*cur,		/* btree cursor */
 733	int			lev,		/* level in btree */
 734	int			lr)		/* left/right bits */
 735{
 736	struct xfs_btree_block	*block;
 737
 738	/*
 739	 * No readahead needed if we are at the root level and the
 740	 * btree root is stored in the inode.
 741	 */
 742	if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
 743	    (lev == cur->bc_nlevels - 1))
 744		return 0;
 745
 746	if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
 747		return 0;
 748
 749	cur->bc_ra[lev] |= lr;
 750	block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
 751
 752	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 753		return xfs_btree_readahead_lblock(cur, lr, block);
 754	return xfs_btree_readahead_sblock(cur, lr, block);
 755}
 756
 757/*
 758 * Set the buffer for level "lev" in the cursor to bp, releasing
 759 * any previous buffer.
 760 */
 761STATIC void
 762xfs_btree_setbuf(
 763	xfs_btree_cur_t		*cur,	/* btree cursor */
 764	int			lev,	/* level in btree */
 765	xfs_buf_t		*bp)	/* new buffer to set */
 766{
 767	struct xfs_btree_block	*b;	/* btree block */
 768
 769	if (cur->bc_bufs[lev])
 770		xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
 771	cur->bc_bufs[lev] = bp;
 772	cur->bc_ra[lev] = 0;
 773
 774	b = XFS_BUF_TO_BLOCK(bp);
 775	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 776		if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO))
 777			cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
 778		if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO))
 779			cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
 780	} else {
 781		if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
 782			cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
 783		if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
 784			cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
 785	}
 786}
 787
 788STATIC int
 789xfs_btree_ptr_is_null(
 790	struct xfs_btree_cur	*cur,
 791	union xfs_btree_ptr	*ptr)
 792{
 793	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 794		return ptr->l == cpu_to_be64(NULLDFSBNO);
 795	else
 796		return ptr->s == cpu_to_be32(NULLAGBLOCK);
 797}
 798
 799STATIC void
 800xfs_btree_set_ptr_null(
 801	struct xfs_btree_cur	*cur,
 802	union xfs_btree_ptr	*ptr)
 803{
 804	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 805		ptr->l = cpu_to_be64(NULLDFSBNO);
 806	else
 807		ptr->s = cpu_to_be32(NULLAGBLOCK);
 808}
 809
 810/*
 811 * Get/set/init sibling pointers
 812 */
 813STATIC void
 814xfs_btree_get_sibling(
 815	struct xfs_btree_cur	*cur,
 816	struct xfs_btree_block	*block,
 817	union xfs_btree_ptr	*ptr,
 818	int			lr)
 819{
 820	ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
 821
 822	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 823		if (lr == XFS_BB_RIGHTSIB)
 824			ptr->l = block->bb_u.l.bb_rightsib;
 825		else
 826			ptr->l = block->bb_u.l.bb_leftsib;
 827	} else {
 828		if (lr == XFS_BB_RIGHTSIB)
 829			ptr->s = block->bb_u.s.bb_rightsib;
 830		else
 831			ptr->s = block->bb_u.s.bb_leftsib;
 832	}
 833}
 834
 835STATIC void
 836xfs_btree_set_sibling(
 837	struct xfs_btree_cur	*cur,
 838	struct xfs_btree_block	*block,
 839	union xfs_btree_ptr	*ptr,
 840	int			lr)
 841{
 842	ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
 843
 844	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 845		if (lr == XFS_BB_RIGHTSIB)
 846			block->bb_u.l.bb_rightsib = ptr->l;
 847		else
 848			block->bb_u.l.bb_leftsib = ptr->l;
 849	} else {
 850		if (lr == XFS_BB_RIGHTSIB)
 851			block->bb_u.s.bb_rightsib = ptr->s;
 852		else
 853			block->bb_u.s.bb_leftsib = ptr->s;
 854	}
 855}
 856
 857STATIC void
 858xfs_btree_init_block(
 859	struct xfs_btree_cur	*cur,
 860	int			level,
 861	int			numrecs,
 862	struct xfs_btree_block	*new)	/* new block */
 863{
 864	new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
 865	new->bb_level = cpu_to_be16(level);
 866	new->bb_numrecs = cpu_to_be16(numrecs);
 867
 868	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 869		new->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
 870		new->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
 871	} else {
 872		new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 873		new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 874	}
 875}
 876
 877/*
 878 * Return true if ptr is the last record in the btree and
 879 * we need to track updateѕ to this record.  The decision
 880 * will be further refined in the update_lastrec method.
 881 */
 882STATIC int
 883xfs_btree_is_lastrec(
 884	struct xfs_btree_cur	*cur,
 885	struct xfs_btree_block	*block,
 886	int			level)
 887{
 888	union xfs_btree_ptr	ptr;
 889
 890	if (level > 0)
 891		return 0;
 892	if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
 893		return 0;
 894
 895	xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
 896	if (!xfs_btree_ptr_is_null(cur, &ptr))
 897		return 0;
 898	return 1;
 899}
 900
 901STATIC void
 902xfs_btree_buf_to_ptr(
 903	struct xfs_btree_cur	*cur,
 904	struct xfs_buf		*bp,
 905	union xfs_btree_ptr	*ptr)
 906{
 907	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 908		ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
 909					XFS_BUF_ADDR(bp)));
 910	else {
 911		ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
 912					XFS_BUF_ADDR(bp)));
 913	}
 914}
 915
 916STATIC xfs_daddr_t
 917xfs_btree_ptr_to_daddr(
 918	struct xfs_btree_cur	*cur,
 919	union xfs_btree_ptr	*ptr)
 920{
 921	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 922		ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO));
 923
 924		return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
 925	} else {
 926		ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
 927		ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
 928
 929		return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
 930					be32_to_cpu(ptr->s));
 931	}
 932}
 933
 934STATIC void
 935xfs_btree_set_refs(
 936	struct xfs_btree_cur	*cur,
 937	struct xfs_buf		*bp)
 938{
 939	switch (cur->bc_btnum) {
 940	case XFS_BTNUM_BNO:
 941	case XFS_BTNUM_CNT:
 942		XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_ALLOC_BTREE_REF);
 943		break;
 944	case XFS_BTNUM_INO:
 945		XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, XFS_INO_BTREE_REF);
 946		break;
 947	case XFS_BTNUM_BMAP:
 948		XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_BMAP_BTREE_REF);
 949		break;
 950	default:
 951		ASSERT(0);
 952	}
 953}
 954
 955STATIC int
 956xfs_btree_get_buf_block(
 957	struct xfs_btree_cur	*cur,
 958	union xfs_btree_ptr	*ptr,
 959	int			flags,
 960	struct xfs_btree_block	**block,
 961	struct xfs_buf		**bpp)
 962{
 963	struct xfs_mount	*mp = cur->bc_mp;
 964	xfs_daddr_t		d;
 965
 966	/* need to sort out how callers deal with failures first */
 967	ASSERT(!(flags & XBF_TRYLOCK));
 968
 969	d = xfs_btree_ptr_to_daddr(cur, ptr);
 970	*bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
 971				 mp->m_bsize, flags);
 972
 973	ASSERT(!xfs_buf_geterror(*bpp));
 974
 975	*block = XFS_BUF_TO_BLOCK(*bpp);
 976	return 0;
 977}
 978
 979/*
 980 * Read in the buffer at the given ptr and return the buffer and
 981 * the block pointer within the buffer.
 982 */
 983STATIC int
 984xfs_btree_read_buf_block(
 985	struct xfs_btree_cur	*cur,
 986	union xfs_btree_ptr	*ptr,
 987	int			level,
 988	int			flags,
 989	struct xfs_btree_block	**block,
 990	struct xfs_buf		**bpp)
 991{
 992	struct xfs_mount	*mp = cur->bc_mp;
 993	xfs_daddr_t		d;
 994	int			error;
 995
 996	/* need to sort out how callers deal with failures first */
 997	ASSERT(!(flags & XBF_TRYLOCK));
 998
 999	d = xfs_btree_ptr_to_daddr(cur, ptr);
1000	error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1001				   mp->m_bsize, flags, bpp);
1002	if (error)
1003		return error;
1004
1005	ASSERT(!xfs_buf_geterror(*bpp));
1006
1007	xfs_btree_set_refs(cur, *bpp);
1008	*block = XFS_BUF_TO_BLOCK(*bpp);
1009
1010	error = xfs_btree_check_block(cur, *block, level, *bpp);
1011	if (error)
1012		xfs_trans_brelse(cur->bc_tp, *bpp);
1013	return error;
1014}
1015
1016/*
1017 * Copy keys from one btree block to another.
1018 */
1019STATIC void
1020xfs_btree_copy_keys(
1021	struct xfs_btree_cur	*cur,
1022	union xfs_btree_key	*dst_key,
1023	union xfs_btree_key	*src_key,
1024	int			numkeys)
1025{
1026	ASSERT(numkeys >= 0);
1027	memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1028}
1029
1030/*
1031 * Copy records from one btree block to another.
1032 */
1033STATIC void
1034xfs_btree_copy_recs(
1035	struct xfs_btree_cur	*cur,
1036	union xfs_btree_rec	*dst_rec,
1037	union xfs_btree_rec	*src_rec,
1038	int			numrecs)
1039{
1040	ASSERT(numrecs >= 0);
1041	memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1042}
1043
1044/*
1045 * Copy block pointers from one btree block to another.
1046 */
1047STATIC void
1048xfs_btree_copy_ptrs(
1049	struct xfs_btree_cur	*cur,
1050	union xfs_btree_ptr	*dst_ptr,
1051	union xfs_btree_ptr	*src_ptr,
1052	int			numptrs)
1053{
1054	ASSERT(numptrs >= 0);
1055	memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1056}
1057
1058/*
1059 * Shift keys one index left/right inside a single btree block.
1060 */
1061STATIC void
1062xfs_btree_shift_keys(
1063	struct xfs_btree_cur	*cur,
1064	union xfs_btree_key	*key,
1065	int			dir,
1066	int			numkeys)
1067{
1068	char			*dst_key;
1069
1070	ASSERT(numkeys >= 0);
1071	ASSERT(dir == 1 || dir == -1);
1072
1073	dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1074	memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1075}
1076
1077/*
1078 * Shift records one index left/right inside a single btree block.
1079 */
1080STATIC void
1081xfs_btree_shift_recs(
1082	struct xfs_btree_cur	*cur,
1083	union xfs_btree_rec	*rec,
1084	int			dir,
1085	int			numrecs)
1086{
1087	char			*dst_rec;
1088
1089	ASSERT(numrecs >= 0);
1090	ASSERT(dir == 1 || dir == -1);
1091
1092	dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1093	memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1094}
1095
1096/*
1097 * Shift block pointers one index left/right inside a single btree block.
1098 */
1099STATIC void
1100xfs_btree_shift_ptrs(
1101	struct xfs_btree_cur	*cur,
1102	union xfs_btree_ptr	*ptr,
1103	int			dir,
1104	int			numptrs)
1105{
1106	char			*dst_ptr;
1107
1108	ASSERT(numptrs >= 0);
1109	ASSERT(dir == 1 || dir == -1);
1110
1111	dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1112	memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1113}
1114
1115/*
1116 * Log key values from the btree block.
1117 */
1118STATIC void
1119xfs_btree_log_keys(
1120	struct xfs_btree_cur	*cur,
1121	struct xfs_buf		*bp,
1122	int			first,
1123	int			last)
1124{
1125	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1126	XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1127
1128	if (bp) {
1129		xfs_trans_log_buf(cur->bc_tp, bp,
1130				  xfs_btree_key_offset(cur, first),
1131				  xfs_btree_key_offset(cur, last + 1) - 1);
1132	} else {
1133		xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1134				xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1135	}
1136
1137	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1138}
1139
1140/*
1141 * Log record values from the btree block.
1142 */
1143void
1144xfs_btree_log_recs(
1145	struct xfs_btree_cur	*cur,
1146	struct xfs_buf		*bp,
1147	int			first,
1148	int			last)
1149{
1150	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1151	XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1152
1153	xfs_trans_log_buf(cur->bc_tp, bp,
1154			  xfs_btree_rec_offset(cur, first),
1155			  xfs_btree_rec_offset(cur, last + 1) - 1);
1156
1157	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1158}
1159
1160/*
1161 * Log block pointer fields from a btree block (nonleaf).
1162 */
1163STATIC void
1164xfs_btree_log_ptrs(
1165	struct xfs_btree_cur	*cur,	/* btree cursor */
1166	struct xfs_buf		*bp,	/* buffer containing btree block */
1167	int			first,	/* index of first pointer to log */
1168	int			last)	/* index of last pointer to log */
1169{
1170	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1171	XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1172
1173	if (bp) {
1174		struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
1175		int			level = xfs_btree_get_level(block);
1176
1177		xfs_trans_log_buf(cur->bc_tp, bp,
1178				xfs_btree_ptr_offset(cur, first, level),
1179				xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1180	} else {
1181		xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1182			xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1183	}
1184
1185	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1186}
1187
1188/*
1189 * Log fields from a btree block header.
1190 */
1191void
1192xfs_btree_log_block(
1193	struct xfs_btree_cur	*cur,	/* btree cursor */
1194	struct xfs_buf		*bp,	/* buffer containing btree block */
1195	int			fields)	/* mask of fields: XFS_BB_... */
1196{
1197	int			first;	/* first byte offset logged */
1198	int			last;	/* last byte offset logged */
1199	static const short	soffsets[] = {	/* table of offsets (short) */
1200		offsetof(struct xfs_btree_block, bb_magic),
1201		offsetof(struct xfs_btree_block, bb_level),
1202		offsetof(struct xfs_btree_block, bb_numrecs),
1203		offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1204		offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1205		XFS_BTREE_SBLOCK_LEN
1206	};
1207	static const short	loffsets[] = {	/* table of offsets (long) */
1208		offsetof(struct xfs_btree_block, bb_magic),
1209		offsetof(struct xfs_btree_block, bb_level),
1210		offsetof(struct xfs_btree_block, bb_numrecs),
1211		offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1212		offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1213		XFS_BTREE_LBLOCK_LEN
1214	};
1215
1216	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1217	XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1218
1219	if (bp) {
1220		xfs_btree_offsets(fields,
1221				  (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1222					loffsets : soffsets,
1223				  XFS_BB_NUM_BITS, &first, &last);
1224		xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1225	} else {
1226		xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1227			xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1228	}
1229
1230	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1231}
1232
1233/*
1234 * Increment cursor by one record at the level.
1235 * For nonzero levels the leaf-ward information is untouched.
1236 */
1237int						/* error */
1238xfs_btree_increment(
1239	struct xfs_btree_cur	*cur,
1240	int			level,
1241	int			*stat)		/* success/failure */
1242{
1243	struct xfs_btree_block	*block;
1244	union xfs_btree_ptr	ptr;
1245	struct xfs_buf		*bp;
1246	int			error;		/* error return value */
1247	int			lev;
1248
1249	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1250	XFS_BTREE_TRACE_ARGI(cur, level);
1251
1252	ASSERT(level < cur->bc_nlevels);
1253
1254	/* Read-ahead to the right at this level. */
1255	xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1256
1257	/* Get a pointer to the btree block. */
1258	block = xfs_btree_get_block(cur, level, &bp);
1259
1260#ifdef DEBUG
1261	error = xfs_btree_check_block(cur, block, level, bp);
1262	if (error)
1263		goto error0;
1264#endif
1265
1266	/* We're done if we remain in the block after the increment. */
1267	if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1268		goto out1;
1269
1270	/* Fail if we just went off the right edge of the tree. */
1271	xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1272	if (xfs_btree_ptr_is_null(cur, &ptr))
1273		goto out0;
1274
1275	XFS_BTREE_STATS_INC(cur, increment);
1276
1277	/*
1278	 * March up the tree incrementing pointers.
1279	 * Stop when we don't go off the right edge of a block.
1280	 */
1281	for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1282		block = xfs_btree_get_block(cur, lev, &bp);
1283
1284#ifdef DEBUG
1285		error = xfs_btree_check_block(cur, block, lev, bp);
1286		if (error)
1287			goto error0;
1288#endif
1289
1290		if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1291			break;
1292
1293		/* Read-ahead the right block for the next loop. */
1294		xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1295	}
1296
1297	/*
1298	 * If we went off the root then we are either seriously
1299	 * confused or have the tree root in an inode.
1300	 */
1301	if (lev == cur->bc_nlevels) {
1302		if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1303			goto out0;
1304		ASSERT(0);
1305		error = EFSCORRUPTED;
1306		goto error0;
1307	}
1308	ASSERT(lev < cur->bc_nlevels);
1309
1310	/*
1311	 * Now walk back down the tree, fixing up the cursor's buffer
1312	 * pointers and key numbers.
1313	 */
1314	for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1315		union xfs_btree_ptr	*ptrp;
1316
1317		ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1318		error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1319							0, &block, &bp);
1320		if (error)
1321			goto error0;
1322
1323		xfs_btree_setbuf(cur, lev, bp);
1324		cur->bc_ptrs[lev] = 1;
1325	}
1326out1:
1327	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1328	*stat = 1;
1329	return 0;
1330
1331out0:
1332	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1333	*stat = 0;
1334	return 0;
1335
1336error0:
1337	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1338	return error;
1339}
1340
1341/*
1342 * Decrement cursor by one record at the level.
1343 * For nonzero levels the leaf-ward information is untouched.
1344 */
1345int						/* error */
1346xfs_btree_decrement(
1347	struct xfs_btree_cur	*cur,
1348	int			level,
1349	int			*stat)		/* success/failure */
1350{
1351	struct xfs_btree_block	*block;
1352	xfs_buf_t		*bp;
1353	int			error;		/* error return value */
1354	int			lev;
1355	union xfs_btree_ptr	ptr;
1356
1357	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1358	XFS_BTREE_TRACE_ARGI(cur, level);
1359
1360	ASSERT(level < cur->bc_nlevels);
1361
1362	/* Read-ahead to the left at this level. */
1363	xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1364
1365	/* We're done if we remain in the block after the decrement. */
1366	if (--cur->bc_ptrs[level] > 0)
1367		goto out1;
1368
1369	/* Get a pointer to the btree block. */
1370	block = xfs_btree_get_block(cur, level, &bp);
1371
1372#ifdef DEBUG
1373	error = xfs_btree_check_block(cur, block, level, bp);
1374	if (error)
1375		goto error0;
1376#endif
1377
1378	/* Fail if we just went off the left edge of the tree. */
1379	xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1380	if (xfs_btree_ptr_is_null(cur, &ptr))
1381		goto out0;
1382
1383	XFS_BTREE_STATS_INC(cur, decrement);
1384
1385	/*
1386	 * March up the tree decrementing pointers.
1387	 * Stop when we don't go off the left edge of a block.
1388	 */
1389	for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1390		if (--cur->bc_ptrs[lev] > 0)
1391			break;
1392		/* Read-ahead the left block for the next loop. */
1393		xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1394	}
1395
1396	/*
1397	 * If we went off the root then we are seriously confused.
1398	 * or the root of the tree is in an inode.
1399	 */
1400	if (lev == cur->bc_nlevels) {
1401		if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1402			goto out0;
1403		ASSERT(0);
1404		error = EFSCORRUPTED;
1405		goto error0;
1406	}
1407	ASSERT(lev < cur->bc_nlevels);
1408
1409	/*
1410	 * Now walk back down the tree, fixing up the cursor's buffer
1411	 * pointers and key numbers.
1412	 */
1413	for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1414		union xfs_btree_ptr	*ptrp;
1415
1416		ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1417		error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1418							0, &block, &bp);
1419		if (error)
1420			goto error0;
1421		xfs_btree_setbuf(cur, lev, bp);
1422		cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1423	}
1424out1:
1425	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1426	*stat = 1;
1427	return 0;
1428
1429out0:
1430	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1431	*stat = 0;
1432	return 0;
1433
1434error0:
1435	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1436	return error;
1437}
1438
1439STATIC int
1440xfs_btree_lookup_get_block(
1441	struct xfs_btree_cur	*cur,	/* btree cursor */
1442	int			level,	/* level in the btree */
1443	union xfs_btree_ptr	*pp,	/* ptr to btree block */
1444	struct xfs_btree_block	**blkp) /* return btree block */
1445{
1446	struct xfs_buf		*bp;	/* buffer pointer for btree block */
1447	int			error = 0;
1448
1449	/* special case the root block if in an inode */
1450	if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1451	    (level == cur->bc_nlevels - 1)) {
1452		*blkp = xfs_btree_get_iroot(cur);
1453		return 0;
1454	}
1455
1456	/*
1457	 * If the old buffer at this level for the disk address we are
1458	 * looking for re-use it.
1459	 *
1460	 * Otherwise throw it away and get a new one.
1461	 */
1462	bp = cur->bc_bufs[level];
1463	if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1464		*blkp = XFS_BUF_TO_BLOCK(bp);
1465		return 0;
1466	}
1467
1468	error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
1469	if (error)
1470		return error;
1471
1472	xfs_btree_setbuf(cur, level, bp);
1473	return 0;
1474}
1475
1476/*
1477 * Get current search key.  For level 0 we don't actually have a key
1478 * structure so we make one up from the record.  For all other levels
1479 * we just return the right key.
1480 */
1481STATIC union xfs_btree_key *
1482xfs_lookup_get_search_key(
1483	struct xfs_btree_cur	*cur,
1484	int			level,
1485	int			keyno,
1486	struct xfs_btree_block	*block,
1487	union xfs_btree_key	*kp)
1488{
1489	if (level == 0) {
1490		cur->bc_ops->init_key_from_rec(kp,
1491				xfs_btree_rec_addr(cur, keyno, block));
1492		return kp;
1493	}
1494
1495	return xfs_btree_key_addr(cur, keyno, block);
1496}
1497
1498/*
1499 * Lookup the record.  The cursor is made to point to it, based on dir.
1500 * Return 0 if can't find any such record, 1 for success.
1501 */
1502int					/* error */
1503xfs_btree_lookup(
1504	struct xfs_btree_cur	*cur,	/* btree cursor */
1505	xfs_lookup_t		dir,	/* <=, ==, or >= */
1506	int			*stat)	/* success/failure */
1507{
1508	struct xfs_btree_block	*block;	/* current btree block */
1509	__int64_t		diff;	/* difference for the current key */
1510	int			error;	/* error return value */
1511	int			keyno;	/* current key number */
1512	int			level;	/* level in the btree */
1513	union xfs_btree_ptr	*pp;	/* ptr to btree block */
1514	union xfs_btree_ptr	ptr;	/* ptr to btree block */
1515
1516	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1517	XFS_BTREE_TRACE_ARGI(cur, dir);
1518
1519	XFS_BTREE_STATS_INC(cur, lookup);
1520
1521	block = NULL;
1522	keyno = 0;
1523
1524	/* initialise start pointer from cursor */
1525	cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1526	pp = &ptr;
1527
1528	/*
1529	 * Iterate over each level in the btree, starting at the root.
1530	 * For each level above the leaves, find the key we need, based
1531	 * on the lookup record, then follow the corresponding block
1532	 * pointer down to the next level.
1533	 */
1534	for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1535		/* Get the block we need to do the lookup on. */
1536		error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1537		if (error)
1538			goto error0;
1539
1540		if (diff == 0) {
1541			/*
1542			 * If we already had a key match at a higher level, we
1543			 * know we need to use the first entry in this block.
1544			 */
1545			keyno = 1;
1546		} else {
1547			/* Otherwise search this block. Do a binary search. */
1548
1549			int	high;	/* high entry number */
1550			int	low;	/* low entry number */
1551
1552			/* Set low and high entry numbers, 1-based. */
1553			low = 1;
1554			high = xfs_btree_get_numrecs(block);
1555			if (!high) {
1556				/* Block is empty, must be an empty leaf. */
1557				ASSERT(level == 0 && cur->bc_nlevels == 1);
1558
1559				cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1560				XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1561				*stat = 0;
1562				return 0;
1563			}
1564
1565			/* Binary search the block. */
1566			while (low <= high) {
1567				union xfs_btree_key	key;
1568				union xfs_btree_key	*kp;
1569
1570				XFS_BTREE_STATS_INC(cur, compare);
1571
1572				/* keyno is average of low and high. */
1573				keyno = (low + high) >> 1;
1574
1575				/* Get current search key */
1576				kp = xfs_lookup_get_search_key(cur, level,
1577						keyno, block, &key);
1578
1579				/*
1580				 * Compute difference to get next direction:
1581				 *  - less than, move right
1582				 *  - greater than, move left
1583				 *  - equal, we're done
1584				 */
1585				diff = cur->bc_ops->key_diff(cur, kp);
1586				if (diff < 0)
1587					low = keyno + 1;
1588				else if (diff > 0)
1589					high = keyno - 1;
1590				else
1591					break;
1592			}
1593		}
1594
1595		/*
1596		 * If there are more levels, set up for the next level
1597		 * by getting the block number and filling in the cursor.
1598		 */
1599		if (level > 0) {
1600			/*
1601			 * If we moved left, need the previous key number,
1602			 * unless there isn't one.
1603			 */
1604			if (diff > 0 && --keyno < 1)
1605				keyno = 1;
1606			pp = xfs_btree_ptr_addr(cur, keyno, block);
1607
1608#ifdef DEBUG
1609			error = xfs_btree_check_ptr(cur, pp, 0, level);
1610			if (error)
1611				goto error0;
1612#endif
1613			cur->bc_ptrs[level] = keyno;
1614		}
1615	}
1616
1617	/* Done with the search. See if we need to adjust the results. */
1618	if (dir != XFS_LOOKUP_LE && diff < 0) {
1619		keyno++;
1620		/*
1621		 * If ge search and we went off the end of the block, but it's
1622		 * not the last block, we're in the wrong block.
1623		 */
1624		xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1625		if (dir == XFS_LOOKUP_GE &&
1626		    keyno > xfs_btree_get_numrecs(block) &&
1627		    !xfs_btree_ptr_is_null(cur, &ptr)) {
1628			int	i;
1629
1630			cur->bc_ptrs[0] = keyno;
1631			error = xfs_btree_increment(cur, 0, &i);
1632			if (error)
1633				goto error0;
1634			XFS_WANT_CORRUPTED_RETURN(i == 1);
1635			XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1636			*stat = 1;
1637			return 0;
1638		}
1639	} else if (dir == XFS_LOOKUP_LE && diff > 0)
1640		keyno--;
1641	cur->bc_ptrs[0] = keyno;
1642
1643	/* Return if we succeeded or not. */
1644	if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1645		*stat = 0;
1646	else if (dir != XFS_LOOKUP_EQ || diff == 0)
1647		*stat = 1;
1648	else
1649		*stat = 0;
1650	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1651	return 0;
1652
1653error0:
1654	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1655	return error;
1656}
1657
1658/*
1659 * Update keys at all levels from here to the root along the cursor's path.
1660 */
1661STATIC int
1662xfs_btree_updkey(
1663	struct xfs_btree_cur	*cur,
1664	union xfs_btree_key	*keyp,
1665	int			level)
1666{
1667	struct xfs_btree_block	*block;
1668	struct xfs_buf		*bp;
1669	union xfs_btree_key	*kp;
1670	int			ptr;
1671
1672	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1673	XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1674
1675	ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1676
1677	/*
1678	 * Go up the tree from this level toward the root.
1679	 * At each level, update the key value to the value input.
1680	 * Stop when we reach a level where the cursor isn't pointing
1681	 * at the first entry in the block.
1682	 */
1683	for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1684#ifdef DEBUG
1685		int		error;
1686#endif
1687		block = xfs_btree_get_block(cur, level, &bp);
1688#ifdef DEBUG
1689		error = xfs_btree_check_block(cur, block, level, bp);
1690		if (error) {
1691			XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1692			return error;
1693		}
1694#endif
1695		ptr = cur->bc_ptrs[level];
1696		kp = xfs_btree_key_addr(cur, ptr, block);
1697		xfs_btree_copy_keys(cur, kp, keyp, 1);
1698		xfs_btree_log_keys(cur, bp, ptr, ptr);
1699	}
1700
1701	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1702	return 0;
1703}
1704
1705/*
1706 * Update the record referred to by cur to the value in the
1707 * given record. This either works (return 0) or gets an
1708 * EFSCORRUPTED error.
1709 */
1710int
1711xfs_btree_update(
1712	struct xfs_btree_cur	*cur,
1713	union xfs_btree_rec	*rec)
1714{
1715	struct xfs_btree_block	*block;
1716	struct xfs_buf		*bp;
1717	int			error;
1718	int			ptr;
1719	union xfs_btree_rec	*rp;
1720
1721	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1722	XFS_BTREE_TRACE_ARGR(cur, rec);
1723
1724	/* Pick up the current block. */
1725	block = xfs_btree_get_block(cur, 0, &bp);
1726
1727#ifdef DEBUG
1728	error = xfs_btree_check_block(cur, block, 0, bp);
1729	if (error)
1730		goto error0;
1731#endif
1732	/* Get the address of the rec to be updated. */
1733	ptr = cur->bc_ptrs[0];
1734	rp = xfs_btree_rec_addr(cur, ptr, block);
1735
1736	/* Fill in the new contents and log them. */
1737	xfs_btree_copy_recs(cur, rp, rec, 1);
1738	xfs_btree_log_recs(cur, bp, ptr, ptr);
1739
1740	/*
1741	 * If we are tracking the last record in the tree and
1742	 * we are at the far right edge of the tree, update it.
1743	 */
1744	if (xfs_btree_is_lastrec(cur, block, 0)) {
1745		cur->bc_ops->update_lastrec(cur, block, rec,
1746					    ptr, LASTREC_UPDATE);
1747	}
1748
1749	/* Updating first rec in leaf. Pass new key value up to our parent. */
1750	if (ptr == 1) {
1751		union xfs_btree_key	key;
1752
1753		cur->bc_ops->init_key_from_rec(&key, rec);
1754		error = xfs_btree_updkey(cur, &key, 1);
1755		if (error)
1756			goto error0;
1757	}
1758
1759	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1760	return 0;
1761
1762error0:
1763	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1764	return error;
1765}
1766
1767/*
1768 * Move 1 record left from cur/level if possible.
1769 * Update cur to reflect the new path.
1770 */
1771STATIC int					/* error */
1772xfs_btree_lshift(
1773	struct xfs_btree_cur	*cur,
1774	int			level,
1775	int			*stat)		/* success/failure */
1776{
1777	union xfs_btree_key	key;		/* btree key */
1778	struct xfs_buf		*lbp;		/* left buffer pointer */
1779	struct xfs_btree_block	*left;		/* left btree block */
1780	int			lrecs;		/* left record count */
1781	struct xfs_buf		*rbp;		/* right buffer pointer */
1782	struct xfs_btree_block	*right;		/* right btree block */
1783	int			rrecs;		/* right record count */
1784	union xfs_btree_ptr	lptr;		/* left btree pointer */
1785	union xfs_btree_key	*rkp = NULL;	/* right btree key */
1786	union xfs_btree_ptr	*rpp = NULL;	/* right address pointer */
1787	union xfs_btree_rec	*rrp = NULL;	/* right record pointer */
1788	int			error;		/* error return value */
1789
1790	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1791	XFS_BTREE_TRACE_ARGI(cur, level);
1792
1793	if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1794	    level == cur->bc_nlevels - 1)
1795		goto out0;
1796
1797	/* Set up variables for this block as "right". */
1798	right = xfs_btree_get_block(cur, level, &rbp);
1799
1800#ifdef DEBUG
1801	error = xfs_btree_check_block(cur, right, level, rbp);
1802	if (error)
1803		goto error0;
1804#endif
1805
1806	/* If we've got no left sibling then we can't shift an entry left. */
1807	xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
1808	if (xfs_btree_ptr_is_null(cur, &lptr))
1809		goto out0;
1810
1811	/*
1812	 * If the cursor entry is the one that would be moved, don't
1813	 * do it... it's too complicated.
1814	 */
1815	if (cur->bc_ptrs[level] <= 1)
1816		goto out0;
1817
1818	/* Set up the left neighbor as "left". */
1819	error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
1820	if (error)
1821		goto error0;
1822
1823	/* If it's full, it can't take another entry. */
1824	lrecs = xfs_btree_get_numrecs(left);
1825	if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
1826		goto out0;
1827
1828	rrecs = xfs_btree_get_numrecs(right);
1829
1830	/*
1831	 * We add one entry to the left side and remove one for the right side.
1832	 * Account for it here, the changes will be updated on disk and logged
1833	 * later.
1834	 */
1835	lrecs++;
1836	rrecs--;
1837
1838	XFS_BTREE_STATS_INC(cur, lshift);
1839	XFS_BTREE_STATS_ADD(cur, moves, 1);
1840
1841	/*
1842	 * If non-leaf, copy a key and a ptr to the left block.
1843	 * Log the changes to the left block.
1844	 */
1845	if (level > 0) {
1846		/* It's a non-leaf.  Move keys and pointers. */
1847		union xfs_btree_key	*lkp;	/* left btree key */
1848		union xfs_btree_ptr	*lpp;	/* left address pointer */
1849
1850		lkp = xfs_btree_key_addr(cur, lrecs, left);
1851		rkp = xfs_btree_key_addr(cur, 1, right);
1852
1853		lpp = xfs_btree_ptr_addr(cur, lrecs, left);
1854		rpp = xfs_btree_ptr_addr(cur, 1, right);
1855#ifdef DEBUG
1856		error = xfs_btree_check_ptr(cur, rpp, 0, level);
1857		if (error)
1858			goto error0;
1859#endif
1860		xfs_btree_copy_keys(cur, lkp, rkp, 1);
1861		xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
1862
1863		xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
1864		xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
1865
1866		ASSERT(cur->bc_ops->keys_inorder(cur,
1867			xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
1868	} else {
1869		/* It's a leaf.  Move records.  */
1870		union xfs_btree_rec	*lrp;	/* left record pointer */
1871
1872		lrp = xfs_btree_rec_addr(cur, lrecs, left);
1873		rrp = xfs_btree_rec_addr(cur, 1, right);
1874
1875		xfs_btree_copy_recs(cur, lrp, rrp, 1);
1876		xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
1877
1878		ASSERT(cur->bc_ops->recs_inorder(cur,
1879			xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
1880	}
1881
1882	xfs_btree_set_numrecs(left, lrecs);
1883	xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
1884
1885	xfs_btree_set_numrecs(right, rrecs);
1886	xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
1887
1888	/*
1889	 * Slide the contents of right down one entry.
1890	 */
1891	XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
1892	if (level > 0) {
1893		/* It's a nonleaf. operate on keys and ptrs */
1894#ifdef DEBUG
1895		int			i;		/* loop index */
1896
1897		for (i = 0; i < rrecs; i++) {
1898			error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
1899			if (error)
1900				goto error0;
1901		}
1902#endif
1903		xfs_btree_shift_keys(cur,
1904				xfs_btree_key_addr(cur, 2, right),
1905				-1, rrecs);
1906		xfs_btree_shift_ptrs(cur,
1907				xfs_btree_ptr_addr(cur, 2, right),
1908				-1, rrecs);
1909
1910		xfs_btree_log_keys(cur, rbp, 1, rrecs);
1911		xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
1912	} else {
1913		/* It's a leaf. operate on records */
1914		xfs_btree_shift_recs(cur,
1915			xfs_btree_rec_addr(cur, 2, right),
1916			-1, rrecs);
1917		xfs_btree_log_recs(cur, rbp, 1, rrecs);
1918
1919		/*
1920		 * If it's the first record in the block, we'll need a key
1921		 * structure to pass up to the next level (updkey).
1922		 */
1923		cur->bc_ops->init_key_from_rec(&key,
1924			xfs_btree_rec_addr(cur, 1, right));
1925		rkp = &key;
1926	}
1927
1928	/* Update the parent key values of right. */
1929	error = xfs_btree_updkey(cur, rkp, level + 1);
1930	if (error)
1931		goto error0;
1932
1933	/* Slide the cursor value left one. */
1934	cur->bc_ptrs[level]--;
1935
1936	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1937	*stat = 1;
1938	return 0;
1939
1940out0:
1941	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1942	*stat = 0;
1943	return 0;
1944
1945error0:
1946	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1947	return error;
1948}
1949
1950/*
1951 * Move 1 record right from cur/level if possible.
1952 * Update cur to reflect the new path.
1953 */
1954STATIC int					/* error */
1955xfs_btree_rshift(
1956	struct xfs_btree_cur	*cur,
1957	int			level,
1958	int			*stat)		/* success/failure */
1959{
1960	union xfs_btree_key	key;		/* btree key */
1961	struct xfs_buf		*lbp;		/* left buffer pointer */
1962	struct xfs_btree_block	*left;		/* left btree block */
1963	struct xfs_buf		*rbp;		/* right buffer pointer */
1964	struct xfs_btree_block	*right;		/* right btree block */
1965	struct xfs_btree_cur	*tcur;		/* temporary btree cursor */
1966	union xfs_btree_ptr	rptr;		/* right block pointer */
1967	union xfs_btree_key	*rkp;		/* right btree key */
1968	int			rrecs;		/* right record count */
1969	int			lrecs;		/* left record count */
1970	int			error;		/* error return value */
1971	int			i;		/* loop counter */
1972
1973	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1974	XFS_BTREE_TRACE_ARGI(cur, level);
1975
1976	if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1977	    (level == cur->bc_nlevels - 1))
1978		goto out0;
1979
1980	/* Set up variables for this block as "left". */
1981	left = xfs_btree_get_block(cur, level, &lbp);
1982
1983#ifdef DEBUG
1984	error = xfs_btree_check_block(cur, left, level, lbp);
1985	if (error)
1986		goto error0;
1987#endif
1988
1989	/* If we've got no right sibling then we can't shift an entry right. */
1990	xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
1991	if (xfs_btree_ptr_is_null(cur, &rptr))
1992		goto out0;
1993
1994	/*
1995	 * If the cursor entry is the one that would be moved, don't
1996	 * do it... it's too complicated.
1997	 */
1998	lrecs = xfs_btree_get_numrecs(left);
1999	if (cur->bc_ptrs[level] >= lrecs)
2000		goto out0;
2001
2002	/* Set up the right neighbor as "right". */
2003	error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
2004	if (error)
2005		goto error0;
2006
2007	/* If it's full, it can't take another entry. */
2008	rrecs = xfs_btree_get_numrecs(right);
2009	if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2010		goto out0;
2011
2012	XFS_BTREE_STATS_INC(cur, rshift);
2013	XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2014
2015	/*
2016	 * Make a hole at the start of the right neighbor block, then
2017	 * copy the last left block entry to the hole.
2018	 */
2019	if (level > 0) {
2020		/* It's a nonleaf. make a hole in the keys and ptrs */
2021		union xfs_btree_key	*lkp;
2022		union xfs_btree_ptr	*lpp;
2023		union xfs_btree_ptr	*rpp;
2024
2025		lkp = xfs_btree_key_addr(cur, lrecs, left);
2026		lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2027		rkp = xfs_btree_key_addr(cur, 1, right);
2028		rpp = xfs_btree_ptr_addr(cur, 1, right);
2029
2030#ifdef DEBUG
2031		for (i = rrecs - 1; i >= 0; i--) {
2032			error = xfs_btree_check_ptr(cur, rpp, i, level);
2033			if (error)
2034				goto error0;
2035		}
2036#endif
2037
2038		xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2039		xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2040
2041#ifdef DEBUG
2042		error = xfs_btree_check_ptr(cur, lpp, 0, level);
2043		if (error)
2044			goto error0;
2045#endif
2046
2047		/* Now put the new data in, and log it. */
2048		xfs_btree_copy_keys(cur, rkp, lkp, 1);
2049		xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2050
2051		xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2052		xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2053
2054		ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2055			xfs_btree_key_addr(cur, 2, right)));
2056	} else {
2057		/* It's a leaf. make a hole in the records */
2058		union xfs_btree_rec	*lrp;
2059		union xfs_btree_rec	*rrp;
2060
2061		lrp = xfs_btree_rec_addr(cur, lrecs, left);
2062		rrp = xfs_btree_rec_addr(cur, 1, right);
2063
2064		xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2065
2066		/* Now put the new data in, and log it. */
2067		xfs_btree_copy_recs(cur, rrp, lrp, 1);
2068		xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2069
2070		cur->bc_ops->init_key_from_rec(&key, rrp);
2071		rkp = &key;
2072
2073		ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
2074			xfs_btree_rec_addr(cur, 2, right)));
2075	}
2076
2077	/*
2078	 * Decrement and log left's numrecs, bump and log right's numrecs.
2079	 */
2080	xfs_btree_set_numrecs(left, --lrecs);
2081	xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2082
2083	xfs_btree_set_numrecs(right, ++rrecs);
2084	xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2085
2086	/*
2087	 * Using a temporary cursor, update the parent key values of the
2088	 * block on the right.
2089	 */
2090	error = xfs_btree_dup_cursor(cur, &tcur);
2091	if (error)
2092		goto error0;
2093	i = xfs_btree_lastrec(tcur, level);
2094	XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2095
2096	error = xfs_btree_increment(tcur, level, &i);
2097	if (error)
2098		goto error1;
2099
2100	error = xfs_btree_updkey(tcur, rkp, level + 1);
2101	if (error)
2102		goto error1;
2103
2104	xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2105
2106	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2107	*stat = 1;
2108	return 0;
2109
2110out0:
2111	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2112	*stat = 0;
2113	return 0;
2114
2115error0:
2116	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2117	return error;
2118
2119error1:
2120	XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2121	xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2122	return error;
2123}
2124
2125/*
2126 * Split cur/level block in half.
2127 * Return new block number and the key to its first
2128 * record (to be inserted into parent).
2129 */
2130STATIC int					/* error */
2131xfs_btree_split(
2132	struct xfs_btree_cur	*cur,
2133	int			level,
2134	union xfs_btree_ptr	*ptrp,
2135	union xfs_btree_key	*key,
2136	struct xfs_btree_cur	**curp,
2137	int			*stat)		/* success/failure */
2138{
2139	union xfs_btree_ptr	lptr;		/* left sibling block ptr */
2140	struct xfs_buf		*lbp;		/* left buffer pointer */
2141	struct xfs_btree_block	*left;		/* left btree block */
2142	union xfs_btree_ptr	rptr;		/* right sibling block ptr */
2143	struct xfs_buf		*rbp;		/* right buffer pointer */
2144	struct xfs_btree_block	*right;		/* right btree block */
2145	union xfs_btree_ptr	rrptr;		/* right-right sibling ptr */
2146	struct xfs_buf		*rrbp;		/* right-right buffer pointer */
2147	struct xfs_btree_block	*rrblock;	/* right-right btree block */
2148	int			lrecs;
2149	int			rrecs;
2150	int			src_index;
2151	int			error;		/* error return value */
2152#ifdef DEBUG
2153	int			i;
2154#endif
2155
2156	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2157	XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2158
2159	XFS_BTREE_STATS_INC(cur, split);
2160
2161	/* Set up left block (current one). */
2162	left = xfs_btree_get_block(cur, level, &lbp);
2163
2164#ifdef DEBUG
2165	error = xfs_btree_check_block(cur, left, level, lbp);
2166	if (error)
2167		goto error0;
2168#endif
2169
2170	xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2171
2172	/* Allocate the new block. If we can't do it, we're toast. Give up. */
2173	error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
2174	if (error)
2175		goto error0;
2176	if (*stat == 0)
2177		goto out0;
2178	XFS_BTREE_STATS_INC(cur, alloc);
2179
2180	/* Set up the new block as "right". */
2181	error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2182	if (error)
2183		goto error0;
2184
2185	/* Fill in the btree header for the new right block. */
2186	xfs_btree_init_block(cur, xfs_btree_get_level(left), 0, right);
2187
2188	/*
2189	 * Split the entries between the old and the new block evenly.
2190	 * Make sure that if there's an odd number of entries now, that
2191	 * each new block will have the same number of entries.
2192	 */
2193	lrecs = xfs_btree_get_numrecs(left);
2194	rrecs = lrecs / 2;
2195	if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2196		rrecs++;
2197	src_index = (lrecs - rrecs + 1);
2198
2199	XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2200
2201	/*
2202	 * Copy btree block entries from the left block over to the
2203	 * new block, the right. Update the right block and log the
2204	 * changes.
2205	 */
2206	if (level > 0) {
2207		/* It's a non-leaf.  Move keys and pointers. */
2208		union xfs_btree_key	*lkp;	/* left btree key */
2209		union xfs_btree_ptr	*lpp;	/* left address pointer */
2210		union xfs_btree_key	*rkp;	/* right btree key */
2211		union xfs_btree_ptr	*rpp;	/* right address pointer */
2212
2213		lkp = xfs_btree_key_addr(cur, src_index, left);
2214		lpp = xfs_btree_ptr_addr(cur, src_index, left);
2215		rkp = xfs_btree_key_addr(cur, 1, right);
2216		rpp = xfs_btree_ptr_addr(cur, 1, right);
2217
2218#ifdef DEBUG
2219		for (i = src_index; i < rrecs; i++) {
2220			error = xfs_btree_check_ptr(cur, lpp, i, level);
2221			if (error)
2222				goto error0;
2223		}
2224#endif
2225
2226		xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2227		xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2228
2229		xfs_btree_log_keys(cur, rbp, 1, rrecs);
2230		xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2231
2232		/* Grab the keys to the entries moved to the right block */
2233		xfs_btree_copy_keys(cur, key, rkp, 1);
2234	} else {
2235		/* It's a leaf.  Move records.  */
2236		union xfs_btree_rec	*lrp;	/* left record pointer */
2237		union xfs_btree_rec	*rrp;	/* right record pointer */
2238
2239		lrp = xfs_btree_rec_addr(cur, src_index, left);
2240		rrp = xfs_btree_rec_addr(cur, 1, right);
2241
2242		xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2243		xfs_btree_log_recs(cur, rbp, 1, rrecs);
2244
2245		cur->bc_ops->init_key_from_rec(key,
2246			xfs_btree_rec_addr(cur, 1, right));
2247	}
2248
2249
2250	/*
2251	 * Find the left block number by looking in the buffer.
2252	 * Adjust numrecs, sibling pointers.
2253	 */
2254	xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2255	xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2256	xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2257	xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2258
2259	lrecs -= rrecs;
2260	xfs_btree_set_numrecs(left, lrecs);
2261	xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2262
2263	xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2264	xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2265
2266	/*
2267	 * If there's a block to the new block's right, make that block
2268	 * point back to right instead of to left.
2269	 */
2270	if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2271		error = xfs_btree_read_buf_block(cur, &rrptr, level,
2272							0, &rrblock, &rrbp);
2273		if (error)
2274			goto error0;
2275		xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2276		xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2277	}
2278	/*
2279	 * If the cursor is really in the right block, move it there.
2280	 * If it's just pointing past the last entry in left, then we'll
2281	 * insert there, so don't change anything in that case.
2282	 */
2283	if (cur->bc_ptrs[level] > lrecs + 1) {
2284		xfs_btree_setbuf(cur, level, rbp);
2285		cur->bc_ptrs[level] -= lrecs;
2286	}
2287	/*
2288	 * If there are more levels, we'll need another cursor which refers
2289	 * the right block, no matter where this cursor was.
2290	 */
2291	if (level + 1 < cur->bc_nlevels) {
2292		error = xfs_btree_dup_cursor(cur, curp);
2293		if (error)
2294			goto error0;
2295		(*curp)->bc_ptrs[level + 1]++;
2296	}
2297	*ptrp = rptr;
2298	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2299	*stat = 1;
2300	return 0;
2301out0:
2302	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2303	*stat = 0;
2304	return 0;
2305
2306error0:
2307	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2308	return error;
2309}
2310
2311/*
2312 * Copy the old inode root contents into a real block and make the
2313 * broot point to it.
2314 */
2315int						/* error */
2316xfs_btree_new_iroot(
2317	struct xfs_btree_cur	*cur,		/* btree cursor */
2318	int			*logflags,	/* logging flags for inode */
2319	int			*stat)		/* return status - 0 fail */
2320{
2321	struct xfs_buf		*cbp;		/* buffer for cblock */
2322	struct xfs_btree_block	*block;		/* btree block */
2323	struct xfs_btree_block	*cblock;	/* child btree block */
2324	union xfs_btree_key	*ckp;		/* child key pointer */
2325	union xfs_btree_ptr	*cpp;		/* child ptr pointer */
2326	union xfs_btree_key	*kp;		/* pointer to btree key */
2327	union xfs_btree_ptr	*pp;		/* pointer to block addr */
2328	union xfs_btree_ptr	nptr;		/* new block addr */
2329	int			level;		/* btree level */
2330	int			error;		/* error return code */
2331#ifdef DEBUG
2332	int			i;		/* loop counter */
2333#endif
2334
2335	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2336	XFS_BTREE_STATS_INC(cur, newroot);
2337
2338	ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2339
2340	level = cur->bc_nlevels - 1;
2341
2342	block = xfs_btree_get_iroot(cur);
2343	pp = xfs_btree_ptr_addr(cur, 1, block);
2344
2345	/* Allocate the new block. If we can't do it, we're toast. Give up. */
2346	error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
2347	if (error)
2348		goto error0;
2349	if (*stat == 0) {
2350		XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2351		return 0;
2352	}
2353	XFS_BTREE_STATS_INC(cur, alloc);
2354
2355	/* Copy the root into a real block. */
2356	error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2357	if (error)
2358		goto error0;
2359
2360	memcpy(cblock, block, xfs_btree_block_len(cur));
2361
2362	be16_add_cpu(&block->bb_level, 1);
2363	xfs_btree_set_numrecs(block, 1);
2364	cur->bc_nlevels++;
2365	cur->bc_ptrs[level + 1] = 1;
2366
2367	kp = xfs_btree_key_addr(cur, 1, block);
2368	ckp = xfs_btree_key_addr(cur, 1, cblock);
2369	xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2370
2371	cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2372#ifdef DEBUG
2373	for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2374		error = xfs_btree_check_ptr(cur, pp, i, level);
2375		if (error)
2376			goto error0;
2377	}
2378#endif
2379	xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2380
2381#ifdef DEBUG
2382	error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2383	if (error)
2384		goto error0;
2385#endif
2386	xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2387
2388	xfs_iroot_realloc(cur->bc_private.b.ip,
2389			  1 - xfs_btree_get_numrecs(cblock),
2390			  cur->bc_private.b.whichfork);
2391
2392	xfs_btree_setbuf(cur, level, cbp);
2393
2394	/*
2395	 * Do all this logging at the end so that
2396	 * the root is at the right level.
2397	 */
2398	xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2399	xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2400	xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2401
2402	*logflags |=
2403		XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
2404	*stat = 1;
2405	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2406	return 0;
2407error0:
2408	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2409	return error;
2410}
2411
2412/*
2413 * Allocate a new root block, fill it in.
2414 */
2415STATIC int				/* error */
2416xfs_btree_new_root(
2417	struct xfs_btree_cur	*cur,	/* btree cursor */
2418	int			*stat)	/* success/failure */
2419{
2420	struct xfs_btree_block	*block;	/* one half of the old root block */
2421	struct xfs_buf		*bp;	/* buffer containing block */
2422	int			error;	/* error return value */
2423	struct xfs_buf		*lbp;	/* left buffer pointer */
2424	struct xfs_btree_block	*left;	/* left btree block */
2425	struct xfs_buf		*nbp;	/* new (root) buffer */
2426	struct xfs_btree_block	*new;	/* new (root) btree block */
2427	int			nptr;	/* new value for key index, 1 or 2 */
2428	struct xfs_buf		*rbp;	/* right buffer pointer */
2429	struct xfs_btree_block	*right;	/* right btree block */
2430	union xfs_btree_ptr	rptr;
2431	union xfs_btree_ptr	lptr;
2432
2433	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2434	XFS_BTREE_STATS_INC(cur, newroot);
2435
2436	/* initialise our start point from the cursor */
2437	cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2438
2439	/* Allocate the new block. If we can't do it, we're toast. Give up. */
2440	error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
2441	if (error)
2442		goto error0;
2443	if (*stat == 0)
2444		goto out0;
2445	XFS_BTREE_STATS_INC(cur, alloc);
2446
2447	/* Set up the new block. */
2448	error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2449	if (error)
2450		goto error0;
2451
2452	/* Set the root in the holding structure  increasing the level by 1. */
2453	cur->bc_ops->set_root(cur, &lptr, 1);
2454
2455	/*
2456	 * At the previous root level there are now two blocks: the old root,
2457	 * and the new block generated when it was split.  We don't know which
2458	 * one the cursor is pointing at, so we set up variables "left" and
2459	 * "right" for each case.
2460	 */
2461	block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2462
2463#ifdef DEBUG
2464	error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2465	if (error)
2466		goto error0;
2467#endif
2468
2469	xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2470	if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2471		/* Our block is left, pick up the right block. */
2472		lbp = bp;
2473		xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2474		left = block;
2475		error = xfs_btree_read_buf_block(cur, &rptr,
2476					cur->bc_nlevels - 1, 0, &right, &rbp);
2477		if (error)
2478			goto error0;
2479		bp = rbp;
2480		nptr = 1;
2481	} else {
2482		/* Our block is right, pick up the left block. */
2483		rbp = bp;
2484		xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2485		right = block;
2486		xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2487		error = xfs_btree_read_buf_block(cur, &lptr,
2488					cur->bc_nlevels - 1, 0, &left, &lbp);
2489		if (error)
2490			goto error0;
2491		bp = lbp;
2492		nptr = 2;
2493	}
2494	/* Fill in the new block's btree header and log it. */
2495	xfs_btree_init_block(cur, cur->bc_nlevels, 2, new);
2496	xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2497	ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2498			!xfs_btree_ptr_is_null(cur, &rptr));
2499
2500	/* Fill in the key data in the new root. */
2501	if (xfs_btree_get_level(left) > 0) {
2502		xfs_btree_copy_keys(cur,
2503				xfs_btree_key_addr(cur, 1, new),
2504				xfs_btree_key_addr(cur, 1, left), 1);
2505		xfs_btree_copy_keys(cur,
2506				xfs_btree_key_addr(cur, 2, new),
2507				xfs_btree_key_addr(cur, 1, right), 1);
2508	} else {
2509		cur->bc_ops->init_key_from_rec(
2510				xfs_btree_key_addr(cur, 1, new),
2511				xfs_btree_rec_addr(cur, 1, left));
2512		cur->bc_ops->init_key_from_rec(
2513				xfs_btree_key_addr(cur, 2, new),
2514				xfs_btree_rec_addr(cur, 1, right));
2515	}
2516	xfs_btree_log_keys(cur, nbp, 1, 2);
2517
2518	/* Fill in the pointer data in the new root. */
2519	xfs_btree_copy_ptrs(cur,
2520		xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2521	xfs_btree_copy_ptrs(cur,
2522		xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2523	xfs_btree_log_ptrs(cur, nbp, 1, 2);
2524
2525	/* Fix up the cursor. */
2526	xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2527	cur->bc_ptrs[cur->bc_nlevels] = nptr;
2528	cur->bc_nlevels++;
2529	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2530	*stat = 1;
2531	return 0;
2532error0:
2533	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2534	return error;
2535out0:
2536	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2537	*stat = 0;
2538	return 0;
2539}
2540
2541STATIC int
2542xfs_btree_make_block_unfull(
2543	struct xfs_btree_cur	*cur,	/* btree cursor */
2544	int			level,	/* btree level */
2545	int			numrecs,/* # of recs in block */
2546	int			*oindex,/* old tree index */
2547	int			*index,	/* new tree index */
2548	union xfs_btree_ptr	*nptr,	/* new btree ptr */
2549	struct xfs_btree_cur	**ncur,	/* new btree cursor */
2550	union xfs_btree_rec	*nrec,	/* new record */
2551	int			*stat)
2552{
2553	union xfs_btree_key	key;	/* new btree key value */
2554	int			error = 0;
2555
2556	if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2557	    level == cur->bc_nlevels - 1) {
2558	    	struct xfs_inode *ip = cur->bc_private.b.ip;
2559
2560		if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2561			/* A root block that can be made bigger. */
2562
2563			xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2564		} else {
2565			/* A root block that needs replacing */
2566			int	logflags = 0;
2567
2568			error = xfs_btree_new_iroot(cur, &logflags, stat);
2569			if (error || *stat == 0)
2570				return error;
2571
2572			xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2573		}
2574
2575		return 0;
2576	}
2577
2578	/* First, try shifting an entry to the right neighbor. */
2579	error = xfs_btree_rshift(cur, level, stat);
2580	if (error || *stat)
2581		return error;
2582
2583	/* Next, try shifting an entry to the left neighbor. */
2584	error = xfs_btree_lshift(cur, level, stat);
2585	if (error)
2586		return error;
2587
2588	if (*stat) {
2589		*oindex = *index = cur->bc_ptrs[level];
2590		return 0;
2591	}
2592
2593	/*
2594	 * Next, try splitting the current block in half.
2595	 *
2596	 * If this works we have to re-set our variables because we
2597	 * could be in a different block now.
2598	 */
2599	error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2600	if (error || *stat == 0)
2601		return error;
2602
2603
2604	*index = cur->bc_ptrs[level];
2605	cur->bc_ops->init_rec_from_key(&key, nrec);
2606	return 0;
2607}
2608
2609/*
2610 * Insert one record/level.  Return information to the caller
2611 * allowing the next level up to proceed if necessary.
2612 */
2613STATIC int
2614xfs_btree_insrec(
2615	struct xfs_btree_cur	*cur,	/* btree cursor */
2616	int			level,	/* level to insert record at */
2617	union xfs_btree_ptr	*ptrp,	/* i/o: block number inserted */
2618	union xfs_btree_rec	*recp,	/* i/o: record data inserted */
2619	struct xfs_btree_cur	**curp,	/* output: new cursor replacing cur */
2620	int			*stat)	/* success/failure */
2621{
2622	struct xfs_btree_block	*block;	/* btree block */
2623	struct xfs_buf		*bp;	/* buffer for block */
2624	union xfs_btree_key	key;	/* btree key */
2625	union xfs_btree_ptr	nptr;	/* new block ptr */
2626	struct xfs_btree_cur	*ncur;	/* new btree cursor */
2627	union xfs_btree_rec	nrec;	/* new record count */
2628	int			optr;	/* old key/record index */
2629	int			ptr;	/* key/record index */
2630	int			numrecs;/* number of records */
2631	int			error;	/* error return value */
2632#ifdef DEBUG
2633	int			i;
2634#endif
2635
2636	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2637	XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2638
2639	ncur = NULL;
2640
2641	/*
2642	 * If we have an external root pointer, and we've made it to the
2643	 * root level, allocate a new root block and we're done.
2644	 */
2645	if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2646	    (level >= cur->bc_nlevels)) {
2647		error = xfs_btree_new_root(cur, stat);
2648		xfs_btree_set_ptr_null(cur, ptrp);
2649
2650		XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2651		return error;
2652	}
2653
2654	/* If we're off the left edge, return failure. */
2655	ptr = cur->bc_ptrs[level];
2656	if (ptr == 0) {
2657		XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2658		*stat = 0;
2659		return 0;
2660	}
2661
2662	/* Make a key out of the record data to be inserted, and save it. */
2663	cur->bc_ops->init_key_from_rec(&key, recp);
2664
2665	optr = ptr;
2666
2667	XFS_BTREE_STATS_INC(cur, insrec);
2668
2669	/* Get pointers to the btree buffer and block. */
2670	block = xfs_btree_get_block(cur, level, &bp);
2671	numrecs = xfs_btree_get_numrecs(block);
2672
2673#ifdef DEBUG
2674	error = xfs_btree_check_block(cur, block, level, bp);
2675	if (error)
2676		goto error0;
2677
2678	/* Check that the new entry is being inserted in the right place. */
2679	if (ptr <= numrecs) {
2680		if (level == 0) {
2681			ASSERT(cur->bc_ops->recs_inorder(cur, recp,
2682				xfs_btree_rec_addr(cur, ptr, block)));
2683		} else {
2684			ASSERT(cur->bc_ops->keys_inorder(cur, &key,
2685				xfs_btree_key_addr(cur, ptr, block)));
2686		}
2687	}
2688#endif
2689
2690	/*
2691	 * If the block is full, we can't insert the new entry until we
2692	 * make the block un-full.
2693	 */
2694	xfs_btree_set_ptr_null(cur, &nptr);
2695	if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
2696		error = xfs_btree_make_block_unfull(cur, level, numrecs,
2697					&optr, &ptr, &nptr, &ncur, &nrec, stat);
2698		if (error || *stat == 0)
2699			goto error0;
2700	}
2701
2702	/*
2703	 * The current block may have changed if the block was
2704	 * previously full and we have just made space in it.
2705	 */
2706	block = xfs_btree_get_block(cur, level, &bp);
2707	numrecs = xfs_btree_get_numrecs(block);
2708
2709#ifdef DEBUG
2710	error = xfs_btree_check_block(cur, block, level, bp);
2711	if (error)
2712		return error;
2713#endif
2714
2715	/*
2716	 * At this point we know there's room for our new entry in the block
2717	 * we're pointing at.
2718	 */
2719	XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
2720
2721	if (level > 0) {
2722		/* It's a nonleaf. make a hole in the keys and ptrs */
2723		union xfs_btree_key	*kp;
2724		union xfs_btree_ptr	*pp;
2725
2726		kp = xfs_btree_key_addr(cur, ptr, block);
2727		pp = xfs_btree_ptr_addr(cur, ptr, block);
2728
2729#ifdef DEBUG
2730		for (i = numrecs - ptr; i >= 0; i--) {
2731			error = xfs_btree_check_ptr(cur, pp, i, level);
2732			if (error)
2733				return error;
2734		}
2735#endif
2736
2737		xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
2738		xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
2739
2740#ifdef DEBUG
2741		error = xfs_btree_check_ptr(cur, ptrp, 0, level);
2742		if (error)
2743			goto error0;
2744#endif
2745
2746		/* Now put the new data in, bump numrecs and log it. */
2747		xfs_btree_copy_keys(cur, kp, &key, 1);
2748		xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
2749		numrecs++;
2750		xfs_btree_set_numrecs(block, numrecs);
2751		xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
2752		xfs_btree_log_keys(cur, bp, ptr, numrecs);
2753#ifdef DEBUG
2754		if (ptr < numrecs) {
2755			ASSERT(cur->bc_ops->keys_inorder(cur, kp,
2756				xfs_btree_key_addr(cur, ptr + 1, block)));
2757		}
2758#endif
2759	} else {
2760		/* It's a leaf. make a hole in the records */
2761		union xfs_btree_rec             *rp;
2762
2763		rp = xfs_btree_rec_addr(cur, ptr, block);
2764
2765		xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
2766
2767		/* Now put the new data in, bump numrecs and log it. */
2768		xfs_btree_copy_recs(cur, rp, recp, 1);
2769		xfs_btree_set_numrecs(block, ++numrecs);
2770		xfs_btree_log_recs(cur, bp, ptr, numrecs);
2771#ifdef DEBUG
2772		if (ptr < numrecs) {
2773			ASSERT(cur->bc_ops->recs_inorder(cur, rp,
2774				xfs_btree_rec_addr(cur, ptr + 1, block)));
2775		}
2776#endif
2777	}
2778
2779	/* Log the new number of records in the btree header. */
2780	xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
2781
2782	/* If we inserted at the start of a block, update the parents' keys. */
2783	if (optr == 1) {
2784		error = xfs_btree_updkey(cur, &key, level + 1);
2785		if (error)
2786			goto error0;
2787	}
2788
2789	/*
2790	 * If we are tracking the last record in the tree and
2791	 * we are at the far right edge of the tree, update it.
2792	 */
2793	if (xfs_btree_is_lastrec(cur, block, level)) {
2794		cur->bc_ops->update_lastrec(cur, block, recp,
2795					    ptr, LASTREC_INSREC);
2796	}
2797
2798	/*
2799	 * Return the new block number, if any.
2800	 * If there is one, give back a record value and a cursor too.
2801	 */
2802	*ptrp = nptr;
2803	if (!xfs_btree_ptr_is_null(cur, &nptr)) {
2804		*recp = nrec;
2805		*curp = ncur;
2806	}
2807
2808	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2809	*stat = 1;
2810	return 0;
2811
2812error0:
2813	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2814	return error;
2815}
2816
2817/*
2818 * Insert the record at the point referenced by cur.
2819 *
2820 * A multi-level split of the tree on insert will invalidate the original
2821 * cursor.  All callers of this function should assume that the cursor is
2822 * no longer valid and revalidate it.
2823 */
2824int
2825xfs_btree_insert(
2826	struct xfs_btree_cur	*cur,
2827	int			*stat)
2828{
2829	int			error;	/* error return value */
2830	int			i;	/* result value, 0 for failure */
2831	int			level;	/* current level number in btree */
2832	union xfs_btree_ptr	nptr;	/* new block number (split result) */
2833	struct xfs_btree_cur	*ncur;	/* new cursor (split result) */
2834	struct xfs_btree_cur	*pcur;	/* previous level's cursor */
2835	union xfs_btree_rec	rec;	/* record to insert */
2836
2837	level = 0;
2838	ncur = NULL;
2839	pcur = cur;
2840
2841	xfs_btree_set_ptr_null(cur, &nptr);
2842	cur->bc_ops->init_rec_from_cur(cur, &rec);
2843
2844	/*
2845	 * Loop going up the tree, starting at the leaf level.
2846	 * Stop when we don't get a split block, that must mean that
2847	 * the insert is finished with this level.
2848	 */
2849	do {
2850		/*
2851		 * Insert nrec/nptr into this level of the tree.
2852		 * Note if we fail, nptr will be null.
2853		 */
2854		error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
2855		if (error) {
2856			if (pcur != cur)
2857				xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
2858			goto error0;
2859		}
2860
2861		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2862		level++;
2863
2864		/*
2865		 * See if the cursor we just used is trash.
2866		 * Can't trash the caller's cursor, but otherwise we should
2867		 * if ncur is a new cursor or we're about to be done.
2868		 */
2869		if (pcur != cur &&
2870		    (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
2871			/* Save the state from the cursor before we trash it */
2872			if (cur->bc_ops->update_cursor)
2873				cur->bc_ops->update_cursor(pcur, cur);
2874			cur->bc_nlevels = pcur->bc_nlevels;
2875			xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
2876		}
2877		/* If we got a new cursor, switch to it. */
2878		if (ncur) {
2879			pcur = ncur;
2880			ncur = NULL;
2881		}
2882	} while (!xfs_btree_ptr_is_null(cur, &nptr));
2883
2884	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2885	*stat = i;
2886	return 0;
2887error0:
2888	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2889	return error;
2890}
2891
2892/*
2893 * Try to merge a non-leaf block back into the inode root.
2894 *
2895 * Note: the killroot names comes from the fact that we're effectively
2896 * killing the old root block.  But because we can't just delete the
2897 * inode we have to copy the single block it was pointing to into the
2898 * inode.
2899 */
2900STATIC int
2901xfs_btree_kill_iroot(
2902	struct xfs_btree_cur	*cur)
2903{
2904	int			whichfork = cur->bc_private.b.whichfork;
2905	struct xfs_inode	*ip = cur->bc_private.b.ip;
2906	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
2907	struct xfs_btree_block	*block;
2908	struct xfs_btree_block	*cblock;
2909	union xfs_btree_key	*kp;
2910	union xfs_btree_key	*ckp;
2911	union xfs_btree_ptr	*pp;
2912	union xfs_btree_ptr	*cpp;
2913	struct xfs_buf		*cbp;
2914	int			level;
2915	int			index;
2916	int			numrecs;
2917#ifdef DEBUG
2918	union xfs_btree_ptr	ptr;
2919	int			i;
2920#endif
2921
2922	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2923
2924	ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2925	ASSERT(cur->bc_nlevels > 1);
2926
2927	/*
2928	 * Don't deal with the root block needs to be a leaf case.
2929	 * We're just going to turn the thing back into extents anyway.
2930	 */
2931	level = cur->bc_nlevels - 1;
2932	if (level == 1)
2933		goto out0;
2934
2935	/*
2936	 * Give up if the root has multiple children.
2937	 */
2938	block = xfs_btree_get_iroot(cur);
2939	if (xfs_btree_get_numrecs(block) != 1)
2940		goto out0;
2941
2942	cblock = xfs_btree_get_block(cur, level - 1, &cbp);
2943	numrecs = xfs_btree_get_numrecs(cblock);
2944
2945	/*
2946	 * Only do this if the next level will fit.
2947	 * Then the data must be copied up to the inode,
2948	 * instead of freeing the root you free the next level.
2949	 */
2950	if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
2951		goto out0;
2952
2953	XFS_BTREE_STATS_INC(cur, killroot);
2954
2955#ifdef DEBUG
2956	xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
2957	ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2958	xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
2959	ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
2960#endif
2961
2962	index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
2963	if (index) {
2964		xfs_iroot_realloc(cur->bc_private.b.ip, index,
2965				  cur->bc_private.b.whichfork);
2966		block = ifp->if_broot;
2967	}
2968
2969	be16_add_cpu(&block->bb_numrecs, index);
2970	ASSERT(block->bb_numrecs == cblock->bb_numrecs);
2971
2972	kp = xfs_btree_key_addr(cur, 1, block);
2973	ckp = xfs_btree_key_addr(cur, 1, cblock);
2974	xfs_btree_copy_keys(cur, kp, ckp, numrecs);
2975
2976	pp = xfs_btree_ptr_addr(cur, 1, block);
2977	cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2978#ifdef DEBUG
2979	for (i = 0; i < numrecs; i++) {
2980		int		error;
2981
2982		error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
2983		if (error) {
2984			XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2985			return error;
2986		}
2987	}
2988#endif
2989	xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
2990
2991	cur->bc_ops->free_block(cur, cbp);
2992	XFS_BTREE_STATS_INC(cur, free);
2993
2994	cur->bc_bufs[level - 1] = NULL;
2995	be16_add_cpu(&block->bb_level, -1);
2996	xfs_trans_log_inode(cur->bc_tp, ip,
2997		XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
2998	cur->bc_nlevels--;
2999out0:
3000	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3001	return 0;
3002}
3003
3004/*
3005 * Kill the current root node, and replace it with it's only child node.
3006 */
3007STATIC int
3008xfs_btree_kill_root(
3009	struct xfs_btree_cur	*cur,
3010	struct xfs_buf		*bp,
3011	int			level,
3012	union xfs_btree_ptr	*newroot)
3013{
3014	int			error;
3015
3016	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3017	XFS_BTREE_STATS_INC(cur, killroot);
3018
3019	/*
3020	 * Update the root pointer, decreasing the level by 1 and then
3021	 * free the old root.
3022	 */
3023	cur->bc_ops->set_root(cur, newroot, -1);
3024
3025	error = cur->bc_ops->free_block(cur, bp);
3026	if (error) {
3027		XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3028		return error;
3029	}
3030
3031	XFS_BTREE_STATS_INC(cur, free);
3032
3033	cur->bc_bufs[level] = NULL;
3034	cur->bc_ra[level] = 0;
3035	cur->bc_nlevels--;
3036
3037	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3038	return 0;
3039}
3040
3041STATIC int
3042xfs_btree_dec_cursor(
3043	struct xfs_btree_cur	*cur,
3044	int			level,
3045	int			*stat)
3046{
3047	int			error;
3048	int			i;
3049
3050	if (level > 0) {
3051		error = xfs_btree_decrement(cur, level, &i);
3052		if (error)
3053			return error;
3054	}
3055
3056	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3057	*stat = 1;
3058	return 0;
3059}
3060
3061/*
3062 * Single level of the btree record deletion routine.
3063 * Delete record pointed to by cur/level.
3064 * Remove the record from its block then rebalance the tree.
3065 * Return 0 for error, 1 for done, 2 to go on to the next level.
3066 */
3067STATIC int					/* error */
3068xfs_btree_delrec(
3069	struct xfs_btree_cur	*cur,		/* btree cursor */
3070	int			level,		/* level removing record from */
3071	int			*stat)		/* fail/done/go-on */
3072{
3073	struct xfs_btree_block	*block;		/* btree block */
3074	union xfs_btree_ptr	cptr;		/* current block ptr */
3075	struct xfs_buf		*bp;		/* buffer for block */
3076	int			error;		/* error return value */
3077	int			i;		/* loop counter */
3078	union xfs_btree_key	key;		/* storage for keyp */
3079	union xfs_btree_key	*keyp = &key;	/* passed to the next level */
3080	union xfs_btree_ptr	lptr;		/* left sibling block ptr */
3081	struct xfs_buf		*lbp;		/* left buffer pointer */
3082	struct xfs_btree_block	*left;		/* left btree block */
3083	int			lrecs = 0;	/* left record count */
3084	int			ptr;		/* key/record index */
3085	union xfs_btree_ptr	rptr;		/* right sibling block ptr */
3086	struct xfs_buf		*rbp;		/* right buffer pointer */
3087	struct xfs_btree_block	*right;		/* right btree block */
3088	struct xfs_btree_block	*rrblock;	/* right-right btree block */
3089	struct xfs_buf		*rrbp;		/* right-right buffer pointer */
3090	int			rrecs = 0;	/* right record count */
3091	struct xfs_btree_cur	*tcur;		/* temporary btree cursor */
3092	int			numrecs;	/* temporary numrec count */
3093
3094	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3095	XFS_BTREE_TRACE_ARGI(cur, level);
3096
3097	tcur = NULL;
3098
3099	/* Get the index of the entry being deleted, check for nothing there. */
3100	ptr = cur->bc_ptrs[level];
3101	if (ptr == 0) {
3102		XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3103		*stat = 0;
3104		return 0;
3105	}
3106
3107	/* Get the buffer & block containing the record or key/ptr. */
3108	block = xfs_btree_get_block(cur, level, &bp);
3109	numrecs = xfs_btree_get_numrecs(block);
3110
3111#ifdef DEBUG
3112	error = xfs_btree_check_block(cur, block, level, bp);
3113	if (error)
3114		goto error0;
3115#endif
3116
3117	/* Fail if we're off the end of the block. */
3118	if (ptr > numrecs) {
3119		XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3120		*stat = 0;
3121		return 0;
3122	}
3123
3124	XFS_BTREE_STATS_INC(cur, delrec);
3125	XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3126
3127	/* Excise the entries being deleted. */
3128	if (level > 0) {
3129		/* It's a nonleaf. operate on keys and ptrs */
3130		union xfs_btree_key	*lkp;
3131		union xfs_btree_ptr	*lpp;
3132
3133		lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3134		lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3135
3136#ifdef DEBUG
3137		for (i = 0; i < numrecs - ptr; i++) {
3138			error = xfs_btree_check_ptr(cur, lpp, i, level);
3139			if (error)
3140				goto error0;
3141		}
3142#endif
3143
3144		if (ptr < numrecs) {
3145			xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3146			xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3147			xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3148			xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3149		}
3150
3151		/*
3152		 * If it's the first record in the block, we'll need to pass a
3153		 * key up to the next level (updkey).
3154		 */
3155		if (ptr == 1)
3156			keyp = xfs_btree_key_addr(cur, 1, block);
3157	} else {
3158		/* It's a leaf. operate on records */
3159		if (ptr < numrecs) {
3160			xfs_btree_shift_recs(cur,
3161				xfs_btree_rec_addr(cur, ptr + 1, block),
3162				-1, numrecs - ptr);
3163			xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3164		}
3165
3166		/*
3167		 * If it's the first record in the block, we'll need a key
3168		 * structure to pass up to the next level (updkey).
3169		 */
3170		if (ptr == 1) {
3171			cur->bc_ops->init_key_from_rec(&key,
3172					xfs_btree_rec_addr(cur, 1, block));
3173			keyp = &key;
3174		}
3175	}
3176
3177	/*
3178	 * Decrement and log the number of entries in the block.
3179	 */
3180	xfs_btree_set_numrecs(block, --numrecs);
3181	xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3182
3183	/*
3184	 * If we are tracking the last record in the tree and
3185	 * we are at the far right edge of the tree, update it.
3186	 */
3187	if (xfs_btree_is_lastrec(cur, block, level)) {
3188		cur->bc_ops->update_lastrec(cur, block, NULL,
3189					    ptr, LASTREC_DELREC);
3190	}
3191
3192	/*
3193	 * We're at the root level.  First, shrink the root block in-memory.
3194	 * Try to get rid of the next level down.  If we can't then there's
3195	 * nothing left to do.
3196	 */
3197	if (level == cur->bc_nlevels - 1) {
3198		if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3199			xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3200					  cur->bc_private.b.whichfork);
3201
3202			error = xfs_btree_kill_iroot(cur);
3203			if (error)
3204				goto error0;
3205
3206			error = xfs_btree_dec_cursor(cur, level, stat);
3207			if (error)
3208				goto error0;
3209			*stat = 1;
3210			return 0;
3211		}
3212
3213		/*
3214		 * If this is the root level, and there's only one entry left,
3215		 * and it's NOT the leaf level, then we can get rid of this
3216		 * level.
3217		 */
3218		if (numrecs == 1 && level > 0) {
3219			union xfs_btree_ptr	*pp;
3220			/*
3221			 * pp is still set to the first pointer in the block.
3222			 * Make it the new root of the btree.
3223			 */
3224			pp = xfs_btree_ptr_addr(cur, 1, block);
3225			error = xfs_btree_kill_root(cur, bp, level, pp);
3226			if (error)
3227				goto error0;
3228		} else if (level > 0) {
3229			error = xfs_btree_dec_cursor(cur, level, stat);
3230			if (error)
3231				goto error0;
3232		}
3233		*stat = 1;
3234		return 0;
3235	}
3236
3237	/*
3238	 * If we deleted the leftmost entry in the block, update the
3239	 * key values above us in the tree.
3240	 */
3241	if (ptr == 1) {
3242		error = xfs_btree_updkey(cur, keyp, level + 1);
3243		if (error)
3244			goto error0;
3245	}
3246
3247	/*
3248	 * If the number of records remaining in the block is at least
3249	 * the minimum, we're done.
3250	 */
3251	if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3252		error = xfs_btree_dec_cursor(cur, level, stat);
3253		if (error)
3254			goto error0;
3255		return 0;
3256	}
3257
3258	/*
3259	 * Otherwise, we have to move some records around to keep the
3260	 * tree balanced.  Look at the left and right sibling blocks to
3261	 * see if we can re-balance by moving only one record.
3262	 */
3263	xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3264	xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3265
3266	if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3267		/*
3268		 * One child of root, need to get a chance to copy its contents
3269		 * into the root and delete it. Can't go up to next level,
3270		 * there's nothing to delete there.
3271		 */
3272		if (xfs_btree_ptr_is_null(cur, &rptr) &&
3273		    xfs_btree_ptr_is_null(cur, &lptr) &&
3274		    level == cur->bc_nlevels - 2) {
3275			error = xfs_btree_kill_iroot(cur);
3276			if (!error)
3277				error = xfs_btree_dec_cursor(cur, level, stat);
3278			if (error)
3279				goto error0;
3280			return 0;
3281		}
3282	}
3283
3284	ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3285	       !xfs_btree_ptr_is_null(cur, &lptr));
3286
3287	/*
3288	 * Duplicate the cursor so our btree manipulations here won't
3289	 * disrupt the next level up.
3290	 */
3291	error = xfs_btree_dup_cursor(cur, &tcur);
3292	if (error)
3293		goto error0;
3294
3295	/*
3296	 * If there's a right sibling, see if it's ok to shift an entry
3297	 * out of it.
3298	 */
3299	if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3300		/*
3301		 * Move the temp cursor to the last entry in the next block.
3302		 * Actually any entry but the first would suffice.
3303		 */
3304		i = xfs_btree_lastrec(tcur, level);
3305		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3306
3307		error = xfs_btree_increment(tcur, level, &i);
3308		if (error)
3309			goto error0;
3310		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3311
3312		i = xfs_btree_lastrec(tcur, level);
3313		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3314
3315		/* Grab a pointer to the block. */
3316		right = xfs_btree_get_block(tcur, level, &rbp);
3317#ifdef DEBUG
3318		error = xfs_btree_check_block(tcur, right, level, rbp);
3319		if (error)
3320			goto error0;
3321#endif
3322		/* Grab the current block number, for future use. */
3323		xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3324
3325		/*
3326		 * If right block is full enough so that removing one entry
3327		 * won't make it too empty, and left-shifting an entry out
3328		 * of right to us works, we're done.
3329		 */
3330		if (xfs_btree_get_numrecs(right) - 1 >=
3331		    cur->bc_ops->get_minrecs(tcur, level)) {
3332			error = xfs_btree_lshift(tcur, level, &i);
3333			if (error)
3334				goto error0;
3335			if (i) {
3336				ASSERT(xfs_btree_get_numrecs(block) >=
3337				       cur->bc_ops->get_minrecs(tcur, level));
3338
3339				xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3340				tcur = NULL;
3341
3342				error = xfs_btree_dec_cursor(cur, level, stat);
3343				if (error)
3344					goto error0;
3345				return 0;
3346			}
3347		}
3348
3349		/*
3350		 * Otherwise, grab the number of records in right for
3351		 * future reference, and fix up the temp cursor to point
3352		 * to our block again (last record).
3353		 */
3354		rrecs = xfs_btree_get_numrecs(right);
3355		if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3356			i = xfs_btree_firstrec(tcur, level);
3357			XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3358
3359			error = xfs_btree_decrement(tcur, level, &i);
3360			if (error)
3361				goto error0;
3362			XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3363		}
3364	}
3365
3366	/*
3367	 * If there's a left sibling, see if it's ok to shift an entry
3368	 * out of it.
3369	 */
3370	if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3371		/*
3372		 * Move the temp cursor to the first entry in the
3373		 * previous block.
3374		 */
3375		i = xfs_btree_firstrec(tcur, level);
3376		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3377
3378		error = xfs_btree_decrement(tcur, level, &i);
3379		if (error)
3380			goto error0;
3381		i = xfs_btree_firstrec(tcur, level);
3382		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3383
3384		/* Grab a pointer to the block. */
3385		left = xfs_btree_get_block(tcur, level, &lbp);
3386#ifdef DEBUG
3387		error = xfs_btree_check_block(cur, left, level, lbp);
3388		if (error)
3389			goto error0;
3390#endif
3391		/* Grab the current block number, for future use. */
3392		xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3393
3394		/*
3395		 * If left block is full enough so that removing one entry
3396		 * won't make it too empty, and right-shifting an entry out
3397		 * of left to us works, we're done.
3398		 */
3399		if (xfs_btree_get_numrecs(left) - 1 >=
3400		    cur->bc_ops->get_minrecs(tcur, level)) {
3401			error = xfs_btree_rshift(tcur, level, &i);
3402			if (error)
3403				goto error0;
3404			if (i) {
3405				ASSERT(xfs_btree_get_numrecs(block) >=
3406				       cur->bc_ops->get_minrecs(tcur, level));
3407				xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3408				tcur = NULL;
3409				if (level == 0)
3410					cur->bc_ptrs[0]++;
3411				XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3412				*stat = 1;
3413				return 0;
3414			}
3415		}
3416
3417		/*
3418		 * Otherwise, grab the number of records in right for
3419		 * future reference.
3420		 */
3421		lrecs = xfs_btree_get_numrecs(left);
3422	}
3423
3424	/* Delete the temp cursor, we're done with it. */
3425	xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3426	tcur = NULL;
3427
3428	/* If here, we need to do a join to keep the tree balanced. */
3429	ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3430
3431	if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3432	    lrecs + xfs_btree_get_numrecs(block) <=
3433			cur->bc_ops->get_maxrecs(cur, level)) {
3434		/*
3435		 * Set "right" to be the starting block,
3436		 * "left" to be the left neighbor.
3437		 */
3438		rptr = cptr;
3439		right = block;
3440		rbp = bp;
3441		error = xfs_btree_read_buf_block(cur, &lptr, level,
3442							0, &left, &lbp);
3443		if (error)
3444			goto error0;
3445
3446	/*
3447	 * If that won't work, see if we can join with the right neighbor block.
3448	 */
3449	} else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3450		   rrecs + xfs_btree_get_numrecs(block) <=
3451			cur->bc_ops->get_maxrecs(cur, level)) {
3452		/*
3453		 * Set "left" to be the starting block,
3454		 * "right" to be the right neighbor.
3455		 */
3456		lptr = cptr;
3457		left = block;
3458		lbp = bp;
3459		error = xfs_btree_read_buf_block(cur, &rptr, level,
3460							0, &right, &rbp);
3461		if (error)
3462			goto error0;
3463
3464	/*
3465	 * Otherwise, we can't fix the imbalance.
3466	 * Just return.  This is probably a logic error, but it's not fatal.
3467	 */
3468	} else {
3469		error = xfs_btree_dec_cursor(cur, level, stat);
3470		if (error)
3471			goto error0;
3472		return 0;
3473	}
3474
3475	rrecs = xfs_btree_get_numrecs(right);
3476	lrecs = xfs_btree_get_numrecs(left);
3477
3478	/*
3479	 * We're now going to join "left" and "right" by moving all the stuff
3480	 * in "right" to "left" and deleting "right".
3481	 */
3482	XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3483	if (level > 0) {
3484		/* It's a non-leaf.  Move keys and pointers. */
3485		union xfs_btree_key	*lkp;	/* left btree key */
3486		union xfs_btree_ptr	*lpp;	/* left address pointer */
3487		union xfs_btree_key	*rkp;	/* right btree key */
3488		union xfs_btree_ptr	*rpp;	/* right address pointer */
3489
3490		lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3491		lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3492		rkp = xfs_btree_key_addr(cur, 1, right);
3493		rpp = xfs_btree_ptr_addr(cur, 1, right);
3494#ifdef DEBUG
3495		for (i = 1; i < rrecs; i++) {
3496			error = xfs_btree_check_ptr(cur, rpp, i, level);
3497			if (error)
3498				goto error0;
3499		}
3500#endif
3501		xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3502		xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3503
3504		xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3505		xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3506	} else {
3507		/* It's a leaf.  Move records.  */
3508		union xfs_btree_rec	*lrp;	/* left record pointer */
3509		union xfs_btree_rec	*rrp;	/* right record pointer */
3510
3511		lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3512		rrp = xfs_btree_rec_addr(cur, 1, right);
3513
3514		xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3515		xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3516	}
3517
3518	XFS_BTREE_STATS_INC(cur, join);
3519
3520	/*
3521	 * Fix up the number of records and right block pointer in the
3522	 * surviving block, and log it.
3523	 */
3524	xfs_btree_set_numrecs(left, lrecs + rrecs);
3525	xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3526	xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3527	xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3528
3529	/* If there is a right sibling, point it to the remaining block. */
3530	xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3531	if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3532		error = xfs_btree_read_buf_block(cur, &cptr, level,
3533							0, &rrblock, &rrbp);
3534		if (error)
3535			goto error0;
3536		xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3537		xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3538	}
3539
3540	/* Free the deleted block. */
3541	error = cur->bc_ops->free_block(cur, rbp);
3542	if (error)
3543		goto error0;
3544	XFS_BTREE_STATS_INC(cur, free);
3545
3546	/*
3547	 * If we joined with the left neighbor, set the buffer in the
3548	 * cursor to the left block, and fix up the index.
3549	 */
3550	if (bp != lbp) {
3551		cur->bc_bufs[level] = lbp;
3552		cur->bc_ptrs[level] += lrecs;
3553		cur->bc_ra[level] = 0;
3554	}
3555	/*
3556	 * If we joined with the right neighbor and there's a level above
3557	 * us, increment the cursor at that level.
3558	 */
3559	else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3560		   (level + 1 < cur->bc_nlevels)) {
3561		error = xfs_btree_increment(cur, level + 1, &i);
3562		if (error)
3563			goto error0;
3564	}
3565
3566	/*
3567	 * Readjust the ptr at this level if it's not a leaf, since it's
3568	 * still pointing at the deletion point, which makes the cursor
3569	 * inconsistent.  If this makes the ptr 0, the caller fixes it up.
3570	 * We can't use decrement because it would change the next level up.
3571	 */
3572	if (level > 0)
3573		cur->bc_ptrs[level]--;
3574
3575	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3576	/* Return value means the next level up has something to do. */
3577	*stat = 2;
3578	return 0;
3579
3580error0:
3581	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3582	if (tcur)
3583		xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3584	return error;
3585}
3586
3587/*
3588 * Delete the record pointed to by cur.
3589 * The cursor refers to the place where the record was (could be inserted)
3590 * when the operation returns.
3591 */
3592int					/* error */
3593xfs_btree_delete(
3594	struct xfs_btree_cur	*cur,
3595	int			*stat)	/* success/failure */
3596{
3597	int			error;	/* error return value */
3598	int			level;
3599	int			i;
3600
3601	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3602
3603	/*
3604	 * Go up the tree, starting at leaf level.
3605	 *
3606	 * If 2 is returned then a join was done; go to the next level.
3607	 * Otherwise we are done.
3608	 */
3609	for (level = 0, i = 2; i == 2; level++) {
3610		error = xfs_btree_delrec(cur, level, &i);
3611		if (error)
3612			goto error0;
3613	}
3614
3615	if (i == 0) {
3616		for (level = 1; level < cur->bc_nlevels; level++) {
3617			if (cur->bc_ptrs[level] == 0) {
3618				error = xfs_btree_decrement(cur, level, &i);
3619				if (error)
3620					goto error0;
3621				break;
3622			}
3623		}
3624	}
3625
3626	XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3627	*stat = i;
3628	return 0;
3629error0:
3630	XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3631	return error;
3632}
3633
3634/*
3635 * Get the data from the pointed-to record.
3636 */
3637int					/* error */
3638xfs_btree_get_rec(
3639	struct xfs_btree_cur	*cur,	/* btree cursor */
3640	union xfs_btree_rec	**recp,	/* output: btree record */
3641	int			*stat)	/* output: success/failure */
3642{
3643	struct xfs_btree_block	*block;	/* btree block */
3644	struct xfs_buf		*bp;	/* buffer pointer */
3645	int			ptr;	/* record number */
3646#ifdef DEBUG
3647	int			error;	/* error return value */
3648#endif
3649
3650	ptr = cur->bc_ptrs[0];
3651	block = xfs_btree_get_block(cur, 0, &bp);
3652
3653#ifdef DEBUG
3654	error = xfs_btree_check_block(cur, block, 0, bp);
3655	if (error)
3656		return error;
3657#endif
3658
3659	/*
3660	 * Off the right end or left end, return failure.
3661	 */
3662	if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3663		*stat = 0;
3664		return 0;
3665	}
3666
3667	/*
3668	 * Point to the record and extract its data.
3669	 */
3670	*recp = xfs_btree_rec_addr(cur, ptr, block);
3671	*stat = 1;
3672	return 0;
3673}