1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
   4 * Copyright (c) 2013 Red Hat, Inc.
   5 * All Rights Reserved.
   6 */
   7#include "xfs.h"
   8#include "xfs_fs.h"
   9#include "xfs_shared.h"
  10#include "xfs_format.h"
  11#include "xfs_log_format.h"
  12#include "xfs_trans_resv.h"
  13#include "xfs_mount.h"
  14#include "xfs_inode.h"
  15#include "xfs_bmap.h"
  16#include "xfs_dir2.h"
  17#include "xfs_dir2_priv.h"
  18#include "xfs_error.h"
  19#include "xfs_trace.h"
  20#include "xfs_trans.h"
  21#include "xfs_buf_item.h"
  22#include "xfs_health.h"
  23
  24/*
  25 * Local function declarations.
  26 */
  27static int xfs_dir2_leaf_lookup_int(xfs_da_args_t *args, struct xfs_buf **lbpp,
  28				    int *indexp, struct xfs_buf **dbpp,
  29				    struct xfs_dir3_icleaf_hdr *leafhdr);
  30static void xfs_dir3_leaf_log_bests(struct xfs_da_args *args,
  31				    struct xfs_buf *bp, int first, int last);
  32static void xfs_dir3_leaf_log_tail(struct xfs_da_args *args,
  33				   struct xfs_buf *bp);
  34
  35void
  36xfs_dir2_leaf_hdr_from_disk(
  37	struct xfs_mount		*mp,
  38	struct xfs_dir3_icleaf_hdr	*to,
  39	struct xfs_dir2_leaf		*from)
  40{
  41	if (xfs_has_crc(mp)) {
  42		struct xfs_dir3_leaf *from3 = (struct xfs_dir3_leaf *)from;
  43
  44		to->forw = be32_to_cpu(from3->hdr.info.hdr.forw);
  45		to->back = be32_to_cpu(from3->hdr.info.hdr.back);
  46		to->magic = be16_to_cpu(from3->hdr.info.hdr.magic);
  47		to->count = be16_to_cpu(from3->hdr.count);
  48		to->stale = be16_to_cpu(from3->hdr.stale);
  49		to->ents = from3->__ents;
  50
  51		ASSERT(to->magic == XFS_DIR3_LEAF1_MAGIC ||
  52		       to->magic == XFS_DIR3_LEAFN_MAGIC);
  53	} else {
  54		to->forw = be32_to_cpu(from->hdr.info.forw);
  55		to->back = be32_to_cpu(from->hdr.info.back);
  56		to->magic = be16_to_cpu(from->hdr.info.magic);
  57		to->count = be16_to_cpu(from->hdr.count);
  58		to->stale = be16_to_cpu(from->hdr.stale);
  59		to->ents = from->__ents;
  60
  61		ASSERT(to->magic == XFS_DIR2_LEAF1_MAGIC ||
  62		       to->magic == XFS_DIR2_LEAFN_MAGIC);
  63	}
  64}
  65
  66void
  67xfs_dir2_leaf_hdr_to_disk(
  68	struct xfs_mount		*mp,
  69	struct xfs_dir2_leaf		*to,
  70	struct xfs_dir3_icleaf_hdr	*from)
  71{
  72	if (xfs_has_crc(mp)) {
  73		struct xfs_dir3_leaf *to3 = (struct xfs_dir3_leaf *)to;
  74
  75		ASSERT(from->magic == XFS_DIR3_LEAF1_MAGIC ||
  76		       from->magic == XFS_DIR3_LEAFN_MAGIC);
  77
  78		to3->hdr.info.hdr.forw = cpu_to_be32(from->forw);
  79		to3->hdr.info.hdr.back = cpu_to_be32(from->back);
  80		to3->hdr.info.hdr.magic = cpu_to_be16(from->magic);
  81		to3->hdr.count = cpu_to_be16(from->count);
  82		to3->hdr.stale = cpu_to_be16(from->stale);
  83	} else {
  84		ASSERT(from->magic == XFS_DIR2_LEAF1_MAGIC ||
  85		       from->magic == XFS_DIR2_LEAFN_MAGIC);
  86
  87		to->hdr.info.forw = cpu_to_be32(from->forw);
  88		to->hdr.info.back = cpu_to_be32(from->back);
  89		to->hdr.info.magic = cpu_to_be16(from->magic);
  90		to->hdr.count = cpu_to_be16(from->count);
  91		to->hdr.stale = cpu_to_be16(from->stale);
  92	}
  93}
  94
  95/*
  96 * Check the internal consistency of a leaf1 block.
  97 * Pop an assert if something is wrong.
  98 */
  99#ifdef DEBUG
 100static xfs_failaddr_t
 101xfs_dir3_leaf1_check(
 102	struct xfs_inode	*dp,
 103	struct xfs_buf		*bp)
 104{
 105	struct xfs_dir2_leaf	*leaf = bp->b_addr;
 106	struct xfs_dir3_icleaf_hdr leafhdr;
 107
 108	xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr, leaf);
 109
 110	if (leafhdr.magic == XFS_DIR3_LEAF1_MAGIC) {
 111		struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr;
 112		if (be64_to_cpu(leaf3->info.blkno) != xfs_buf_daddr(bp))
 113			return __this_address;
 114	} else if (leafhdr.magic != XFS_DIR2_LEAF1_MAGIC)
 115		return __this_address;
 116
 117	return xfs_dir3_leaf_check_int(dp->i_mount, &leafhdr, leaf, false);
 118}
 119
 120static inline void
 121xfs_dir3_leaf_check(
 122	struct xfs_inode	*dp,
 123	struct xfs_buf		*bp)
 124{
 125	xfs_failaddr_t		fa;
 126
 127	fa = xfs_dir3_leaf1_check(dp, bp);
 128	if (!fa)
 129		return;
 130	xfs_corruption_error(__func__, XFS_ERRLEVEL_LOW, dp->i_mount,
 131			bp->b_addr, BBTOB(bp->b_length), __FILE__, __LINE__,
 132			fa);
 133	ASSERT(0);
 134}
 135#else
 136#define	xfs_dir3_leaf_check(dp, bp)
 137#endif
 138
 139xfs_failaddr_t
 140xfs_dir3_leaf_check_int(
 141	struct xfs_mount		*mp,
 142	struct xfs_dir3_icleaf_hdr	*hdr,
 143	struct xfs_dir2_leaf		*leaf,
 144	bool				expensive_checking)
 145{
 146	struct xfs_da_geometry		*geo = mp->m_dir_geo;
 147	xfs_dir2_leaf_tail_t		*ltp;
 148	int				stale;
 149	int				i;
 150	bool				isleaf1 = (hdr->magic == XFS_DIR2_LEAF1_MAGIC ||
 151						   hdr->magic == XFS_DIR3_LEAF1_MAGIC);
 152
 153	ltp = xfs_dir2_leaf_tail_p(geo, leaf);
 154
 155	/*
 156	 * XXX (dgc): This value is not restrictive enough.
 157	 * Should factor in the size of the bests table as well.
 158	 * We can deduce a value for that from i_disk_size.
 159	 */
 160	if (hdr->count > geo->leaf_max_ents)
 161		return __this_address;
 162
 163	/* Leaves and bests don't overlap in leaf format. */
 164	if (isleaf1 &&
 
 165	    (char *)&hdr->ents[hdr->count] > (char *)xfs_dir2_leaf_bests_p(ltp))
 166		return __this_address;
 167
 168	if (!expensive_checking)
 169		return NULL;
 170
 171	/* Check hash value order, count stale entries.  */
 172	for (i = stale = 0; i < hdr->count; i++) {
 173		if (i + 1 < hdr->count) {
 174			if (be32_to_cpu(hdr->ents[i].hashval) >
 175					be32_to_cpu(hdr->ents[i + 1].hashval))
 176				return __this_address;
 177		}
 178		if (hdr->ents[i].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 179			stale++;
 180		if (isleaf1 && xfs_dir2_dataptr_to_db(geo,
 181				be32_to_cpu(hdr->ents[i].address)) >=
 182				be32_to_cpu(ltp->bestcount))
 183			return __this_address;
 184	}
 185	if (hdr->stale != stale)
 186		return __this_address;
 187	return NULL;
 188}
 189
 190/*
 191 * We verify the magic numbers before decoding the leaf header so that on debug
 192 * kernels we don't get assertion failures in xfs_dir3_leaf_hdr_from_disk() due
 193 * to incorrect magic numbers.
 194 */
 195static xfs_failaddr_t
 196xfs_dir3_leaf_verify(
 197	struct xfs_buf			*bp)
 198{
 199	struct xfs_mount		*mp = bp->b_mount;
 200	struct xfs_dir3_icleaf_hdr	leafhdr;
 201	xfs_failaddr_t			fa;
 202
 203	fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
 204	if (fa)
 205		return fa;
 206
 207	xfs_dir2_leaf_hdr_from_disk(mp, &leafhdr, bp->b_addr);
 208	return xfs_dir3_leaf_check_int(mp, &leafhdr, bp->b_addr, true);
 209}
 210
 211static void
 212xfs_dir3_leaf_read_verify(
 213	struct xfs_buf  *bp)
 214{
 215	struct xfs_mount	*mp = bp->b_mount;
 216	xfs_failaddr_t		fa;
 217
 218	if (xfs_has_crc(mp) &&
 219	     !xfs_buf_verify_cksum(bp, XFS_DIR3_LEAF_CRC_OFF))
 220		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 221	else {
 222		fa = xfs_dir3_leaf_verify(bp);
 223		if (fa)
 224			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 225	}
 226}
 227
 228static void
 229xfs_dir3_leaf_write_verify(
 230	struct xfs_buf  *bp)
 231{
 232	struct xfs_mount	*mp = bp->b_mount;
 233	struct xfs_buf_log_item	*bip = bp->b_log_item;
 234	struct xfs_dir3_leaf_hdr *hdr3 = bp->b_addr;
 235	xfs_failaddr_t		fa;
 236
 237	fa = xfs_dir3_leaf_verify(bp);
 238	if (fa) {
 239		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 240		return;
 241	}
 242
 243	if (!xfs_has_crc(mp))
 244		return;
 245
 246	if (bip)
 247		hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
 248
 249	xfs_buf_update_cksum(bp, XFS_DIR3_LEAF_CRC_OFF);
 250}
 251
 252const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops = {
 253	.name = "xfs_dir3_leaf1",
 254	.magic16 = { cpu_to_be16(XFS_DIR2_LEAF1_MAGIC),
 255		     cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) },
 256	.verify_read = xfs_dir3_leaf_read_verify,
 257	.verify_write = xfs_dir3_leaf_write_verify,
 258	.verify_struct = xfs_dir3_leaf_verify,
 259};
 260
 261const struct xfs_buf_ops xfs_dir3_leafn_buf_ops = {
 262	.name = "xfs_dir3_leafn",
 263	.magic16 = { cpu_to_be16(XFS_DIR2_LEAFN_MAGIC),
 264		     cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) },
 265	.verify_read = xfs_dir3_leaf_read_verify,
 266	.verify_write = xfs_dir3_leaf_write_verify,
 267	.verify_struct = xfs_dir3_leaf_verify,
 268};
 269
 270int
 271xfs_dir3_leaf_read(
 272	struct xfs_trans	*tp,
 273	struct xfs_inode	*dp,
 274	xfs_dablk_t		fbno,
 275	struct xfs_buf		**bpp)
 276{
 277	int			err;
 278
 279	err = xfs_da_read_buf(tp, dp, fbno, 0, bpp, XFS_DATA_FORK,
 280			&xfs_dir3_leaf1_buf_ops);
 281	if (!err && tp && *bpp)
 282		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_LEAF1_BUF);
 283	return err;
 284}
 285
 286int
 287xfs_dir3_leafn_read(
 288	struct xfs_trans	*tp,
 289	struct xfs_inode	*dp,
 290	xfs_dablk_t		fbno,
 291	struct xfs_buf		**bpp)
 292{
 293	int			err;
 294
 295	err = xfs_da_read_buf(tp, dp, fbno, 0, bpp, XFS_DATA_FORK,
 296			&xfs_dir3_leafn_buf_ops);
 297	if (!err && tp && *bpp)
 298		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_LEAFN_BUF);
 299	return err;
 300}
 301
 302/*
 303 * Initialize a new leaf block, leaf1 or leafn magic accepted.
 304 */
 305static void
 306xfs_dir3_leaf_init(
 307	struct xfs_mount	*mp,
 308	struct xfs_trans	*tp,
 309	struct xfs_buf		*bp,
 310	xfs_ino_t		owner,
 311	uint16_t		type)
 312{
 313	struct xfs_dir2_leaf	*leaf = bp->b_addr;
 314
 315	ASSERT(type == XFS_DIR2_LEAF1_MAGIC || type == XFS_DIR2_LEAFN_MAGIC);
 316
 317	if (xfs_has_crc(mp)) {
 318		struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr;
 319
 320		memset(leaf3, 0, sizeof(*leaf3));
 321
 322		leaf3->info.hdr.magic = (type == XFS_DIR2_LEAF1_MAGIC)
 323					 ? cpu_to_be16(XFS_DIR3_LEAF1_MAGIC)
 324					 : cpu_to_be16(XFS_DIR3_LEAFN_MAGIC);
 325		leaf3->info.blkno = cpu_to_be64(xfs_buf_daddr(bp));
 326		leaf3->info.owner = cpu_to_be64(owner);
 327		uuid_copy(&leaf3->info.uuid, &mp->m_sb.sb_meta_uuid);
 328	} else {
 329		memset(leaf, 0, sizeof(*leaf));
 330		leaf->hdr.info.magic = cpu_to_be16(type);
 331	}
 332
 333	/*
 334	 * If it's a leaf-format directory initialize the tail.
 335	 * Caller is responsible for initialising the bests table.
 336	 */
 337	if (type == XFS_DIR2_LEAF1_MAGIC) {
 338		struct xfs_dir2_leaf_tail *ltp;
 339
 340		ltp = xfs_dir2_leaf_tail_p(mp->m_dir_geo, leaf);
 341		ltp->bestcount = 0;
 342		bp->b_ops = &xfs_dir3_leaf1_buf_ops;
 343		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAF1_BUF);
 344	} else {
 345		bp->b_ops = &xfs_dir3_leafn_buf_ops;
 346		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
 347	}
 348}
 349
 350int
 351xfs_dir3_leaf_get_buf(
 352	xfs_da_args_t		*args,
 353	xfs_dir2_db_t		bno,
 354	struct xfs_buf		**bpp,
 355	uint16_t		magic)
 356{
 357	struct xfs_inode	*dp = args->dp;
 358	struct xfs_trans	*tp = args->trans;
 359	struct xfs_mount	*mp = dp->i_mount;
 360	struct xfs_buf		*bp;
 361	int			error;
 362
 363	ASSERT(magic == XFS_DIR2_LEAF1_MAGIC || magic == XFS_DIR2_LEAFN_MAGIC);
 364	ASSERT(bno >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET) &&
 365	       bno < xfs_dir2_byte_to_db(args->geo, XFS_DIR2_FREE_OFFSET));
 366
 367	error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(args->geo, bno),
 368			       &bp, XFS_DATA_FORK);
 369	if (error)
 370		return error;
 371
 372	xfs_dir3_leaf_init(mp, tp, bp, dp->i_ino, magic);
 373	xfs_dir3_leaf_log_header(args, bp);
 374	if (magic == XFS_DIR2_LEAF1_MAGIC)
 375		xfs_dir3_leaf_log_tail(args, bp);
 376	*bpp = bp;
 377	return 0;
 378}
 379
 380/*
 381 * Convert a block form directory to a leaf form directory.
 382 */
 383int						/* error */
 384xfs_dir2_block_to_leaf(
 385	xfs_da_args_t		*args,		/* operation arguments */
 386	struct xfs_buf		*dbp)		/* input block's buffer */
 387{
 388	__be16			*bestsp;	/* leaf's bestsp entries */
 389	xfs_dablk_t		blkno;		/* leaf block's bno */
 390	xfs_dir2_data_hdr_t	*hdr;		/* block header */
 391	xfs_dir2_leaf_entry_t	*blp;		/* block's leaf entries */
 392	xfs_dir2_block_tail_t	*btp;		/* block's tail */
 393	xfs_inode_t		*dp;		/* incore directory inode */
 394	int			error;		/* error return code */
 395	struct xfs_buf		*lbp;		/* leaf block's buffer */
 396	xfs_dir2_db_t		ldb;		/* leaf block's bno */
 397	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
 398	xfs_dir2_leaf_tail_t	*ltp;		/* leaf's tail */
 399	int			needlog;	/* need to log block header */
 400	int			needscan;	/* need to rescan bestfree */
 401	xfs_trans_t		*tp;		/* transaction pointer */
 402	struct xfs_dir2_data_free *bf;
 403	struct xfs_dir3_icleaf_hdr leafhdr;
 404
 405	trace_xfs_dir2_block_to_leaf(args);
 406
 407	dp = args->dp;
 408	tp = args->trans;
 409	/*
 410	 * Add the leaf block to the inode.
 411	 * This interface will only put blocks in the leaf/node range.
 412	 * Since that's empty now, we'll get the root (block 0 in range).
 413	 */
 414	if ((error = xfs_da_grow_inode(args, &blkno))) {
 415		return error;
 416	}
 417	ldb = xfs_dir2_da_to_db(args->geo, blkno);
 418	ASSERT(ldb == xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET));
 419	/*
 420	 * Initialize the leaf block, get a buffer for it.
 421	 */
 422	error = xfs_dir3_leaf_get_buf(args, ldb, &lbp, XFS_DIR2_LEAF1_MAGIC);
 423	if (error)
 424		return error;
 425
 426	leaf = lbp->b_addr;
 427	hdr = dbp->b_addr;
 428	xfs_dir3_data_check(dp, dbp);
 429	btp = xfs_dir2_block_tail_p(args->geo, hdr);
 430	blp = xfs_dir2_block_leaf_p(btp);
 431	bf = xfs_dir2_data_bestfree_p(dp->i_mount, hdr);
 432
 433	/*
 434	 * Set the counts in the leaf header.
 435	 */
 436	xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr, leaf);
 437	leafhdr.count = be32_to_cpu(btp->count);
 438	leafhdr.stale = be32_to_cpu(btp->stale);
 439	xfs_dir2_leaf_hdr_to_disk(dp->i_mount, leaf, &leafhdr);
 440	xfs_dir3_leaf_log_header(args, lbp);
 441
 442	/*
 443	 * Could compact these but I think we always do the conversion
 444	 * after squeezing out stale entries.
 445	 */
 446	memcpy(leafhdr.ents, blp,
 447		be32_to_cpu(btp->count) * sizeof(struct xfs_dir2_leaf_entry));
 448	xfs_dir3_leaf_log_ents(args, &leafhdr, lbp, 0, leafhdr.count - 1);
 449	needscan = 0;
 450	needlog = 1;
 451	/*
 452	 * Make the space formerly occupied by the leaf entries and block
 453	 * tail be free.
 454	 */
 455	xfs_dir2_data_make_free(args, dbp,
 456		(xfs_dir2_data_aoff_t)((char *)blp - (char *)hdr),
 457		(xfs_dir2_data_aoff_t)((char *)hdr + args->geo->blksize -
 458				       (char *)blp),
 459		&needlog, &needscan);
 460	/*
 461	 * Fix up the block header, make it a data block.
 462	 */
 463	dbp->b_ops = &xfs_dir3_data_buf_ops;
 464	xfs_trans_buf_set_type(tp, dbp, XFS_BLFT_DIR_DATA_BUF);
 465	if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC))
 466		hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 467	else
 468		hdr->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
 469
 470	if (needscan)
 471		xfs_dir2_data_freescan(dp->i_mount, hdr, &needlog);
 472	/*
 473	 * Set up leaf tail and bests table.
 474	 */
 475	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
 476	ltp->bestcount = cpu_to_be32(1);
 477	bestsp = xfs_dir2_leaf_bests_p(ltp);
 478	bestsp[0] =  bf[0].length;
 479	/*
 480	 * Log the data header and leaf bests table.
 481	 */
 482	if (needlog)
 483		xfs_dir2_data_log_header(args, dbp);
 484	xfs_dir3_leaf_check(dp, lbp);
 485	xfs_dir3_data_check(dp, dbp);
 486	xfs_dir3_leaf_log_bests(args, lbp, 0, 0);
 487	return 0;
 488}
 489
 490STATIC void
 491xfs_dir3_leaf_find_stale(
 492	struct xfs_dir3_icleaf_hdr *leafhdr,
 493	struct xfs_dir2_leaf_entry *ents,
 494	int			index,
 495	int			*lowstale,
 496	int			*highstale)
 497{
 498	/*
 499	 * Find the first stale entry before our index, if any.
 500	 */
 501	for (*lowstale = index - 1; *lowstale >= 0; --*lowstale) {
 502		if (ents[*lowstale].address ==
 503		    cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 504			break;
 505	}
 506
 507	/*
 508	 * Find the first stale entry at or after our index, if any.
 509	 * Stop if the result would require moving more entries than using
 510	 * lowstale.
 511	 */
 512	for (*highstale = index; *highstale < leafhdr->count; ++*highstale) {
 513		if (ents[*highstale].address ==
 514		    cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 515			break;
 516		if (*lowstale >= 0 && index - *lowstale <= *highstale - index)
 517			break;
 518	}
 519}
 520
 521struct xfs_dir2_leaf_entry *
 522xfs_dir3_leaf_find_entry(
 523	struct xfs_dir3_icleaf_hdr *leafhdr,
 524	struct xfs_dir2_leaf_entry *ents,
 525	int			index,		/* leaf table position */
 526	int			compact,	/* need to compact leaves */
 527	int			lowstale,	/* index of prev stale leaf */
 528	int			highstale,	/* index of next stale leaf */
 529	int			*lfloglow,	/* low leaf logging index */
 530	int			*lfloghigh)	/* high leaf logging index */
 531{
 532	if (!leafhdr->stale) {
 533		xfs_dir2_leaf_entry_t	*lep;	/* leaf entry table pointer */
 534
 535		/*
 536		 * Now we need to make room to insert the leaf entry.
 537		 *
 538		 * If there are no stale entries, just insert a hole at index.
 539		 */
 540		lep = &ents[index];
 541		if (index < leafhdr->count)
 542			memmove(lep + 1, lep,
 543				(leafhdr->count - index) * sizeof(*lep));
 544
 545		/*
 546		 * Record low and high logging indices for the leaf.
 547		 */
 548		*lfloglow = index;
 549		*lfloghigh = leafhdr->count++;
 550		return lep;
 551	}
 552
 553	/*
 554	 * There are stale entries.
 555	 *
 556	 * We will use one of them for the new entry.  It's probably not at
 557	 * the right location, so we'll have to shift some up or down first.
 558	 *
 559	 * If we didn't compact before, we need to find the nearest stale
 560	 * entries before and after our insertion point.
 561	 */
 562	if (compact == 0)
 563		xfs_dir3_leaf_find_stale(leafhdr, ents, index,
 564					 &lowstale, &highstale);
 565
 566	/*
 567	 * If the low one is better, use it.
 568	 */
 569	if (lowstale >= 0 &&
 570	    (highstale == leafhdr->count ||
 571	     index - lowstale - 1 < highstale - index)) {
 572		ASSERT(index - lowstale - 1 >= 0);
 573		ASSERT(ents[lowstale].address ==
 574		       cpu_to_be32(XFS_DIR2_NULL_DATAPTR));
 575
 576		/*
 577		 * Copy entries up to cover the stale entry and make room
 578		 * for the new entry.
 579		 */
 580		if (index - lowstale - 1 > 0) {
 581			memmove(&ents[lowstale], &ents[lowstale + 1],
 582				(index - lowstale - 1) *
 583					sizeof(xfs_dir2_leaf_entry_t));
 584		}
 585		*lfloglow = min(lowstale, *lfloglow);
 586		*lfloghigh = max(index - 1, *lfloghigh);
 587		leafhdr->stale--;
 588		return &ents[index - 1];
 589	}
 590
 591	/*
 592	 * The high one is better, so use that one.
 593	 */
 594	ASSERT(highstale - index >= 0);
 595	ASSERT(ents[highstale].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR));
 596
 597	/*
 598	 * Copy entries down to cover the stale entry and make room for the
 599	 * new entry.
 600	 */
 601	if (highstale - index > 0) {
 602		memmove(&ents[index + 1], &ents[index],
 603			(highstale - index) * sizeof(xfs_dir2_leaf_entry_t));
 604	}
 605	*lfloglow = min(index, *lfloglow);
 606	*lfloghigh = max(highstale, *lfloghigh);
 607	leafhdr->stale--;
 608	return &ents[index];
 609}
 610
 611/*
 612 * Add an entry to a leaf form directory.
 613 */
 614int						/* error */
 615xfs_dir2_leaf_addname(
 616	struct xfs_da_args	*args)		/* operation arguments */
 617{
 618	struct xfs_dir3_icleaf_hdr leafhdr;
 619	struct xfs_trans	*tp = args->trans;
 620	__be16			*bestsp;	/* freespace table in leaf */
 621	__be16			*tagp;		/* end of data entry */
 622	struct xfs_buf		*dbp;		/* data block buffer */
 623	struct xfs_buf		*lbp;		/* leaf's buffer */
 624	struct xfs_dir2_leaf	*leaf;		/* leaf structure */
 625	struct xfs_inode	*dp = args->dp;	/* incore directory inode */
 626	struct xfs_dir2_data_hdr *hdr;		/* data block header */
 627	struct xfs_dir2_data_entry *dep;	/* data block entry */
 628	struct xfs_dir2_leaf_entry *lep;	/* leaf entry table pointer */
 629	struct xfs_dir2_leaf_entry *ents;
 630	struct xfs_dir2_data_unused *dup;	/* data unused entry */
 631	struct xfs_dir2_leaf_tail *ltp;		/* leaf tail pointer */
 632	struct xfs_dir2_data_free *bf;		/* bestfree table */
 633	int			compact;	/* need to compact leaves */
 634	int			error;		/* error return value */
 635	int			grown;		/* allocated new data block */
 636	int			highstale = 0;	/* index of next stale leaf */
 637	int			i;		/* temporary, index */
 638	int			index;		/* leaf table position */
 639	int			length;		/* length of new entry */
 640	int			lfloglow;	/* low leaf logging index */
 641	int			lfloghigh;	/* high leaf logging index */
 642	int			lowstale = 0;	/* index of prev stale leaf */
 643	int			needbytes;	/* leaf block bytes needed */
 644	int			needlog;	/* need to log data header */
 645	int			needscan;	/* need to rescan data free */
 646	xfs_dir2_db_t		use_block;	/* data block number */
 647
 648	trace_xfs_dir2_leaf_addname(args);
 649
 650	error = xfs_dir3_leaf_read(tp, dp, args->geo->leafblk, &lbp);
 651	if (error)
 652		return error;
 653
 654	/*
 655	 * Look up the entry by hash value and name.
 656	 * We know it's not there, our caller has already done a lookup.
 657	 * So the index is of the entry to insert in front of.
 658	 * But if there are dup hash values the index is of the first of those.
 659	 */
 660	index = xfs_dir2_leaf_search_hash(args, lbp);
 661	leaf = lbp->b_addr;
 662	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
 663	xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr, leaf);
 664	ents = leafhdr.ents;
 665	bestsp = xfs_dir2_leaf_bests_p(ltp);
 666	length = xfs_dir2_data_entsize(dp->i_mount, args->namelen);
 667
 668	/*
 669	 * See if there are any entries with the same hash value
 670	 * and space in their block for the new entry.
 671	 * This is good because it puts multiple same-hash value entries
 672	 * in a data block, improving the lookup of those entries.
 673	 */
 674	for (use_block = -1, lep = &ents[index];
 675	     index < leafhdr.count && be32_to_cpu(lep->hashval) == args->hashval;
 676	     index++, lep++) {
 677		if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
 678			continue;
 679		i = xfs_dir2_dataptr_to_db(args->geo, be32_to_cpu(lep->address));
 680		ASSERT(i < be32_to_cpu(ltp->bestcount));
 681		ASSERT(bestsp[i] != cpu_to_be16(NULLDATAOFF));
 682		if (be16_to_cpu(bestsp[i]) >= length) {
 683			use_block = i;
 684			break;
 685		}
 686	}
 687	/*
 688	 * Didn't find a block yet, linear search all the data blocks.
 689	 */
 690	if (use_block == -1) {
 691		for (i = 0; i < be32_to_cpu(ltp->bestcount); i++) {
 692			/*
 693			 * Remember a block we see that's missing.
 694			 */
 695			if (bestsp[i] == cpu_to_be16(NULLDATAOFF) &&
 696			    use_block == -1)
 697				use_block = i;
 698			else if (be16_to_cpu(bestsp[i]) >= length) {
 699				use_block = i;
 700				break;
 701			}
 702		}
 703	}
 704	/*
 705	 * How many bytes do we need in the leaf block?
 706	 */
 707	needbytes = 0;
 708	if (!leafhdr.stale)
 709		needbytes += sizeof(xfs_dir2_leaf_entry_t);
 710	if (use_block == -1)
 711		needbytes += sizeof(xfs_dir2_data_off_t);
 712
 713	/*
 714	 * Now kill use_block if it refers to a missing block, so we
 715	 * can use it as an indication of allocation needed.
 716	 */
 717	if (use_block != -1 && bestsp[use_block] == cpu_to_be16(NULLDATAOFF))
 718		use_block = -1;
 719	/*
 720	 * If we don't have enough free bytes but we can make enough
 721	 * by compacting out stale entries, we'll do that.
 722	 */
 723	if ((char *)bestsp - (char *)&ents[leafhdr.count] < needbytes &&
 724	    leafhdr.stale > 1)
 725		compact = 1;
 726
 727	/*
 728	 * Otherwise if we don't have enough free bytes we need to
 729	 * convert to node form.
 730	 */
 731	else if ((char *)bestsp - (char *)&ents[leafhdr.count] < needbytes) {
 732		/*
 733		 * Just checking or no space reservation, give up.
 734		 */
 735		if ((args->op_flags & XFS_DA_OP_JUSTCHECK) ||
 736							args->total == 0) {
 737			xfs_trans_brelse(tp, lbp);
 738			return -ENOSPC;
 739		}
 740		/*
 741		 * Convert to node form.
 742		 */
 743		error = xfs_dir2_leaf_to_node(args, lbp);
 744		if (error)
 745			return error;
 746		/*
 747		 * Then add the new entry.
 748		 */
 749		return xfs_dir2_node_addname(args);
 750	}
 751	/*
 752	 * Otherwise it will fit without compaction.
 753	 */
 754	else
 755		compact = 0;
 756	/*
 757	 * If just checking, then it will fit unless we needed to allocate
 758	 * a new data block.
 759	 */
 760	if (args->op_flags & XFS_DA_OP_JUSTCHECK) {
 761		xfs_trans_brelse(tp, lbp);
 762		return use_block == -1 ? -ENOSPC : 0;
 763	}
 764	/*
 765	 * If no allocations are allowed, return now before we've
 766	 * changed anything.
 767	 */
 768	if (args->total == 0 && use_block == -1) {
 769		xfs_trans_brelse(tp, lbp);
 770		return -ENOSPC;
 771	}
 772	/*
 773	 * Need to compact the leaf entries, removing stale ones.
 774	 * Leave one stale entry behind - the one closest to our
 775	 * insertion index - and we'll shift that one to our insertion
 776	 * point later.
 777	 */
 778	if (compact) {
 779		xfs_dir3_leaf_compact_x1(&leafhdr, ents, &index, &lowstale,
 780			&highstale, &lfloglow, &lfloghigh);
 781	}
 782	/*
 783	 * There are stale entries, so we'll need log-low and log-high
 784	 * impossibly bad values later.
 785	 */
 786	else if (leafhdr.stale) {
 787		lfloglow = leafhdr.count;
 788		lfloghigh = -1;
 789	}
 790	/*
 791	 * If there was no data block space found, we need to allocate
 792	 * a new one.
 793	 */
 794	if (use_block == -1) {
 795		/*
 796		 * Add the new data block.
 797		 */
 798		if ((error = xfs_dir2_grow_inode(args, XFS_DIR2_DATA_SPACE,
 799				&use_block))) {
 800			xfs_trans_brelse(tp, lbp);
 801			return error;
 802		}
 803		/*
 804		 * Initialize the block.
 805		 */
 806		if ((error = xfs_dir3_data_init(args, use_block, &dbp))) {
 807			xfs_trans_brelse(tp, lbp);
 808			return error;
 809		}
 810		/*
 811		 * If we're adding a new data block on the end we need to
 812		 * extend the bests table.  Copy it up one entry.
 813		 */
 814		if (use_block >= be32_to_cpu(ltp->bestcount)) {
 815			bestsp--;
 816			memmove(&bestsp[0], &bestsp[1],
 817				be32_to_cpu(ltp->bestcount) * sizeof(bestsp[0]));
 818			be32_add_cpu(&ltp->bestcount, 1);
 819			xfs_dir3_leaf_log_tail(args, lbp);
 820			xfs_dir3_leaf_log_bests(args, lbp, 0,
 821						be32_to_cpu(ltp->bestcount) - 1);
 822		}
 823		/*
 824		 * If we're filling in a previously empty block just log it.
 825		 */
 826		else
 827			xfs_dir3_leaf_log_bests(args, lbp, use_block, use_block);
 828		hdr = dbp->b_addr;
 829		bf = xfs_dir2_data_bestfree_p(dp->i_mount, hdr);
 830		bestsp[use_block] = bf[0].length;
 831		grown = 1;
 832	} else {
 833		/*
 834		 * Already had space in some data block.
 835		 * Just read that one in.
 836		 */
 837		error = xfs_dir3_data_read(tp, dp,
 838				   xfs_dir2_db_to_da(args->geo, use_block),
 839				   0, &dbp);
 840		if (error) {
 841			xfs_trans_brelse(tp, lbp);
 842			return error;
 843		}
 844		hdr = dbp->b_addr;
 845		bf = xfs_dir2_data_bestfree_p(dp->i_mount, hdr);
 846		grown = 0;
 847	}
 848	/*
 849	 * Point to the biggest freespace in our data block.
 850	 */
 851	dup = (xfs_dir2_data_unused_t *)
 852	      ((char *)hdr + be16_to_cpu(bf[0].offset));
 853	needscan = needlog = 0;
 854	/*
 855	 * Mark the initial part of our freespace in use for the new entry.
 856	 */
 857	error = xfs_dir2_data_use_free(args, dbp, dup,
 858			(xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr),
 859			length, &needlog, &needscan);
 860	if (error) {
 861		xfs_trans_brelse(tp, lbp);
 862		return error;
 863	}
 864	/*
 865	 * Initialize our new entry (at last).
 866	 */
 867	dep = (xfs_dir2_data_entry_t *)dup;
 868	dep->inumber = cpu_to_be64(args->inumber);
 869	dep->namelen = args->namelen;
 870	memcpy(dep->name, args->name, dep->namelen);
 871	xfs_dir2_data_put_ftype(dp->i_mount, dep, args->filetype);
 872	tagp = xfs_dir2_data_entry_tag_p(dp->i_mount, dep);
 873	*tagp = cpu_to_be16((char *)dep - (char *)hdr);
 874	/*
 875	 * Need to scan fix up the bestfree table.
 876	 */
 877	if (needscan)
 878		xfs_dir2_data_freescan(dp->i_mount, hdr, &needlog);
 879	/*
 880	 * Need to log the data block's header.
 881	 */
 882	if (needlog)
 883		xfs_dir2_data_log_header(args, dbp);
 884	xfs_dir2_data_log_entry(args, dbp, dep);
 885	/*
 886	 * If the bests table needs to be changed, do it.
 887	 * Log the change unless we've already done that.
 888	 */
 889	if (be16_to_cpu(bestsp[use_block]) != be16_to_cpu(bf[0].length)) {
 890		bestsp[use_block] = bf[0].length;
 891		if (!grown)
 892			xfs_dir3_leaf_log_bests(args, lbp, use_block, use_block);
 893	}
 894
 895	lep = xfs_dir3_leaf_find_entry(&leafhdr, ents, index, compact, lowstale,
 896				       highstale, &lfloglow, &lfloghigh);
 897
 898	/*
 899	 * Fill in the new leaf entry.
 900	 */
 901	lep->hashval = cpu_to_be32(args->hashval);
 902	lep->address = cpu_to_be32(
 903				xfs_dir2_db_off_to_dataptr(args->geo, use_block,
 904				be16_to_cpu(*tagp)));
 905	/*
 906	 * Log the leaf fields and give up the buffers.
 907	 */
 908	xfs_dir2_leaf_hdr_to_disk(dp->i_mount, leaf, &leafhdr);
 909	xfs_dir3_leaf_log_header(args, lbp);
 910	xfs_dir3_leaf_log_ents(args, &leafhdr, lbp, lfloglow, lfloghigh);
 911	xfs_dir3_leaf_check(dp, lbp);
 912	xfs_dir3_data_check(dp, dbp);
 913	return 0;
 914}
 915
 916/*
 917 * Compact out any stale entries in the leaf.
 918 * Log the header and changed leaf entries, if any.
 919 */
 920void
 921xfs_dir3_leaf_compact(
 922	xfs_da_args_t	*args,		/* operation arguments */
 923	struct xfs_dir3_icleaf_hdr *leafhdr,
 924	struct xfs_buf	*bp)		/* leaf buffer */
 925{
 926	int		from;		/* source leaf index */
 927	xfs_dir2_leaf_t	*leaf;		/* leaf structure */
 928	int		loglow;		/* first leaf entry to log */
 929	int		to;		/* target leaf index */
 930	struct xfs_inode *dp = args->dp;
 931
 932	leaf = bp->b_addr;
 933	if (!leafhdr->stale)
 934		return;
 935
 936	/*
 937	 * Compress out the stale entries in place.
 938	 */
 939	for (from = to = 0, loglow = -1; from < leafhdr->count; from++) {
 940		if (leafhdr->ents[from].address ==
 941		    cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 942			continue;
 943		/*
 944		 * Only actually copy the entries that are different.
 945		 */
 946		if (from > to) {
 947			if (loglow == -1)
 948				loglow = to;
 949			leafhdr->ents[to] = leafhdr->ents[from];
 950		}
 951		to++;
 952	}
 953	/*
 954	 * Update and log the header, log the leaf entries.
 955	 */
 956	ASSERT(leafhdr->stale == from - to);
 957	leafhdr->count -= leafhdr->stale;
 958	leafhdr->stale = 0;
 959
 960	xfs_dir2_leaf_hdr_to_disk(dp->i_mount, leaf, leafhdr);
 961	xfs_dir3_leaf_log_header(args, bp);
 962	if (loglow != -1)
 963		xfs_dir3_leaf_log_ents(args, leafhdr, bp, loglow, to - 1);
 964}
 965
 966/*
 967 * Compact the leaf entries, removing stale ones.
 968 * Leave one stale entry behind - the one closest to our
 969 * insertion index - and the caller will shift that one to our insertion
 970 * point later.
 971 * Return new insertion index, where the remaining stale entry is,
 972 * and leaf logging indices.
 973 */
 974void
 975xfs_dir3_leaf_compact_x1(
 976	struct xfs_dir3_icleaf_hdr *leafhdr,
 977	struct xfs_dir2_leaf_entry *ents,
 978	int		*indexp,	/* insertion index */
 979	int		*lowstalep,	/* out: stale entry before us */
 980	int		*highstalep,	/* out: stale entry after us */
 981	int		*lowlogp,	/* out: low log index */
 982	int		*highlogp)	/* out: high log index */
 983{
 984	int		from;		/* source copy index */
 985	int		highstale;	/* stale entry at/after index */
 986	int		index;		/* insertion index */
 987	int		keepstale;	/* source index of kept stale */
 988	int		lowstale;	/* stale entry before index */
 989	int		newindex=0;	/* new insertion index */
 990	int		to;		/* destination copy index */
 991
 992	ASSERT(leafhdr->stale > 1);
 993	index = *indexp;
 994
 995	xfs_dir3_leaf_find_stale(leafhdr, ents, index, &lowstale, &highstale);
 996
 997	/*
 998	 * Pick the better of lowstale and highstale.
 999	 */
1000	if (lowstale >= 0 &&
1001	    (highstale == leafhdr->count ||
1002	     index - lowstale <= highstale - index))
1003		keepstale = lowstale;
1004	else
1005		keepstale = highstale;
1006	/*
1007	 * Copy the entries in place, removing all the stale entries
1008	 * except keepstale.
1009	 */
1010	for (from = to = 0; from < leafhdr->count; from++) {
1011		/*
1012		 * Notice the new value of index.
1013		 */
1014		if (index == from)
1015			newindex = to;
1016		if (from != keepstale &&
1017		    ents[from].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR)) {
1018			if (from == to)
1019				*lowlogp = to;
1020			continue;
1021		}
1022		/*
1023		 * Record the new keepstale value for the insertion.
1024		 */
1025		if (from == keepstale)
1026			lowstale = highstale = to;
1027		/*
1028		 * Copy only the entries that have moved.
1029		 */
1030		if (from > to)
1031			ents[to] = ents[from];
1032		to++;
1033	}
1034	ASSERT(from > to);
1035	/*
1036	 * If the insertion point was past the last entry,
1037	 * set the new insertion point accordingly.
1038	 */
1039	if (index == from)
1040		newindex = to;
1041	*indexp = newindex;
1042	/*
1043	 * Adjust the leaf header values.
1044	 */
1045	leafhdr->count -= from - to;
1046	leafhdr->stale = 1;
1047	/*
1048	 * Remember the low/high stale value only in the "right"
1049	 * direction.
1050	 */
1051	if (lowstale >= newindex)
1052		lowstale = -1;
1053	else
1054		highstale = leafhdr->count;
1055	*highlogp = leafhdr->count - 1;
1056	*lowstalep = lowstale;
1057	*highstalep = highstale;
1058}
1059
1060/*
1061 * Log the bests entries indicated from a leaf1 block.
1062 */
1063static void
1064xfs_dir3_leaf_log_bests(
1065	struct xfs_da_args	*args,
1066	struct xfs_buf		*bp,		/* leaf buffer */
1067	int			first,		/* first entry to log */
1068	int			last)		/* last entry to log */
1069{
1070	__be16			*firstb;	/* pointer to first entry */
1071	__be16			*lastb;		/* pointer to last entry */
1072	struct xfs_dir2_leaf	*leaf = bp->b_addr;
1073	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
1074
1075	ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC) ||
1076	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC));
1077
1078	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
1079	firstb = xfs_dir2_leaf_bests_p(ltp) + first;
1080	lastb = xfs_dir2_leaf_bests_p(ltp) + last;
1081	xfs_trans_log_buf(args->trans, bp,
1082		(uint)((char *)firstb - (char *)leaf),
1083		(uint)((char *)lastb - (char *)leaf + sizeof(*lastb) - 1));
1084}
1085
1086/*
1087 * Log the leaf entries indicated from a leaf1 or leafn block.
1088 */
1089void
1090xfs_dir3_leaf_log_ents(
1091	struct xfs_da_args	*args,
1092	struct xfs_dir3_icleaf_hdr *hdr,
1093	struct xfs_buf		*bp,
1094	int			first,
1095	int			last)
1096{
1097	xfs_dir2_leaf_entry_t	*firstlep;	/* pointer to first entry */
1098	xfs_dir2_leaf_entry_t	*lastlep;	/* pointer to last entry */
1099	struct xfs_dir2_leaf	*leaf = bp->b_addr;
1100
1101	ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC) ||
1102	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) ||
1103	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1104	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC));
1105
1106	firstlep = &hdr->ents[first];
1107	lastlep = &hdr->ents[last];
1108	xfs_trans_log_buf(args->trans, bp,
1109		(uint)((char *)firstlep - (char *)leaf),
1110		(uint)((char *)lastlep - (char *)leaf + sizeof(*lastlep) - 1));
1111}
1112
1113/*
1114 * Log the header of the leaf1 or leafn block.
1115 */
1116void
1117xfs_dir3_leaf_log_header(
1118	struct xfs_da_args	*args,
1119	struct xfs_buf		*bp)
1120{
1121	struct xfs_dir2_leaf	*leaf = bp->b_addr;
1122
1123	ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC) ||
1124	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) ||
1125	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1126	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC));
1127
1128	xfs_trans_log_buf(args->trans, bp,
1129			  (uint)((char *)&leaf->hdr - (char *)leaf),
1130			  args->geo->leaf_hdr_size - 1);
1131}
1132
1133/*
1134 * Log the tail of the leaf1 block.
1135 */
1136STATIC void
1137xfs_dir3_leaf_log_tail(
1138	struct xfs_da_args	*args,
1139	struct xfs_buf		*bp)
1140{
1141	struct xfs_dir2_leaf	*leaf = bp->b_addr;
1142	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
1143
1144	ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC) ||
1145	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) ||
1146	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1147	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC));
1148
1149	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
1150	xfs_trans_log_buf(args->trans, bp, (uint)((char *)ltp - (char *)leaf),
1151		(uint)(args->geo->blksize - 1));
1152}
1153
1154/*
1155 * Look up the entry referred to by args in the leaf format directory.
1156 * Most of the work is done by the xfs_dir2_leaf_lookup_int routine which
1157 * is also used by the node-format code.
1158 */
1159int
1160xfs_dir2_leaf_lookup(
1161	xfs_da_args_t		*args)		/* operation arguments */
1162{
1163	struct xfs_buf		*dbp;		/* data block buffer */
1164	xfs_dir2_data_entry_t	*dep;		/* data block entry */
1165	xfs_inode_t		*dp;		/* incore directory inode */
1166	int			error;		/* error return code */
1167	int			index;		/* found entry index */
1168	struct xfs_buf		*lbp;		/* leaf buffer */
1169	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1170	xfs_trans_t		*tp;		/* transaction pointer */
1171	struct xfs_dir3_icleaf_hdr leafhdr;
1172
1173	trace_xfs_dir2_leaf_lookup(args);
1174
1175	/*
1176	 * Look up name in the leaf block, returning both buffers and index.
1177	 */
1178	error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp, &leafhdr);
1179	if (error)
1180		return error;
1181
1182	tp = args->trans;
1183	dp = args->dp;
1184	xfs_dir3_leaf_check(dp, lbp);
1185
1186	/*
1187	 * Get to the leaf entry and contained data entry address.
1188	 */
1189	lep = &leafhdr.ents[index];
1190
1191	/*
1192	 * Point to the data entry.
1193	 */
1194	dep = (xfs_dir2_data_entry_t *)
1195	      ((char *)dbp->b_addr +
1196	       xfs_dir2_dataptr_to_off(args->geo, be32_to_cpu(lep->address)));
1197	/*
1198	 * Return the found inode number & CI name if appropriate
1199	 */
1200	args->inumber = be64_to_cpu(dep->inumber);
1201	args->filetype = xfs_dir2_data_get_ftype(dp->i_mount, dep);
1202	error = xfs_dir_cilookup_result(args, dep->name, dep->namelen);
1203	xfs_trans_brelse(tp, dbp);
1204	xfs_trans_brelse(tp, lbp);
1205	return error;
1206}
1207
1208/*
1209 * Look up name/hash in the leaf block.
1210 * Fill in indexp with the found index, and dbpp with the data buffer.
1211 * If not found dbpp will be NULL, and ENOENT comes back.
1212 * lbpp will always be filled in with the leaf buffer unless there's an error.
1213 */
1214static int					/* error */
1215xfs_dir2_leaf_lookup_int(
1216	xfs_da_args_t		*args,		/* operation arguments */
1217	struct xfs_buf		**lbpp,		/* out: leaf buffer */
1218	int			*indexp,	/* out: index in leaf block */
1219	struct xfs_buf		**dbpp,		/* out: data buffer */
1220	struct xfs_dir3_icleaf_hdr *leafhdr)
1221{
1222	xfs_dir2_db_t		curdb = -1;	/* current data block number */
1223	struct xfs_buf		*dbp = NULL;	/* data buffer */
1224	xfs_dir2_data_entry_t	*dep;		/* data entry */
1225	xfs_inode_t		*dp;		/* incore directory inode */
1226	int			error;		/* error return code */
1227	int			index;		/* index in leaf block */
1228	struct xfs_buf		*lbp;		/* leaf buffer */
1229	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1230	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1231	xfs_mount_t		*mp;		/* filesystem mount point */
1232	xfs_dir2_db_t		newdb;		/* new data block number */
1233	xfs_trans_t		*tp;		/* transaction pointer */
1234	xfs_dir2_db_t		cidb = -1;	/* case match data block no. */
1235	enum xfs_dacmp		cmp;		/* name compare result */
1236
1237	dp = args->dp;
1238	tp = args->trans;
1239	mp = dp->i_mount;
1240
1241	error = xfs_dir3_leaf_read(tp, dp, args->geo->leafblk, &lbp);
1242	if (error)
1243		return error;
1244
1245	*lbpp = lbp;
1246	leaf = lbp->b_addr;
1247	xfs_dir3_leaf_check(dp, lbp);
1248	xfs_dir2_leaf_hdr_from_disk(mp, leafhdr, leaf);
1249
1250	/*
1251	 * Look for the first leaf entry with our hash value.
1252	 */
1253	index = xfs_dir2_leaf_search_hash(args, lbp);
1254	/*
1255	 * Loop over all the entries with the right hash value
1256	 * looking to match the name.
1257	 */
1258	for (lep = &leafhdr->ents[index];
1259	     index < leafhdr->count &&
1260			be32_to_cpu(lep->hashval) == args->hashval;
1261	     lep++, index++) {
1262		/*
1263		 * Skip over stale leaf entries.
1264		 */
1265		if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
1266			continue;
1267		/*
1268		 * Get the new data block number.
1269		 */
1270		newdb = xfs_dir2_dataptr_to_db(args->geo,
1271					       be32_to_cpu(lep->address));
1272		/*
1273		 * If it's not the same as the old data block number,
1274		 * need to pitch the old one and read the new one.
1275		 */
1276		if (newdb != curdb) {
1277			if (dbp)
1278				xfs_trans_brelse(tp, dbp);
1279			error = xfs_dir3_data_read(tp, dp,
1280					   xfs_dir2_db_to_da(args->geo, newdb),
1281					   0, &dbp);
1282			if (error) {
1283				xfs_trans_brelse(tp, lbp);
1284				return error;
1285			}
1286			curdb = newdb;
1287		}
1288		/*
1289		 * Point to the data entry.
1290		 */
1291		dep = (xfs_dir2_data_entry_t *)((char *)dbp->b_addr +
1292			xfs_dir2_dataptr_to_off(args->geo,
1293						be32_to_cpu(lep->address)));
1294		/*
1295		 * Compare name and if it's an exact match, return the index
1296		 * and buffer. If it's the first case-insensitive match, store
1297		 * the index and buffer and continue looking for an exact match.
1298		 */
1299		cmp = xfs_dir2_compname(args, dep->name, dep->namelen);
1300		if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
1301			args->cmpresult = cmp;
1302			*indexp = index;
1303			/* case exact match: return the current buffer. */
1304			if (cmp == XFS_CMP_EXACT) {
1305				*dbpp = dbp;
1306				return 0;
1307			}
1308			cidb = curdb;
1309		}
1310	}
1311	ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1312	/*
1313	 * Here, we can only be doing a lookup (not a rename or remove).
1314	 * If a case-insensitive match was found earlier, re-read the
1315	 * appropriate data block if required and return it.
1316	 */
1317	if (args->cmpresult == XFS_CMP_CASE) {
1318		ASSERT(cidb != -1);
1319		if (cidb != curdb) {
1320			xfs_trans_brelse(tp, dbp);
1321			error = xfs_dir3_data_read(tp, dp,
1322					   xfs_dir2_db_to_da(args->geo, cidb),
1323					   0, &dbp);
1324			if (error) {
1325				xfs_trans_brelse(tp, lbp);
1326				return error;
1327			}
1328		}
1329		*dbpp = dbp;
1330		return 0;
1331	}
1332	/*
1333	 * No match found, return -ENOENT.
1334	 */
1335	ASSERT(cidb == -1);
1336	if (dbp)
1337		xfs_trans_brelse(tp, dbp);
1338	xfs_trans_brelse(tp, lbp);
1339	return -ENOENT;
1340}
1341
1342/*
1343 * Remove an entry from a leaf format directory.
1344 */
1345int						/* error */
1346xfs_dir2_leaf_removename(
1347	xfs_da_args_t		*args)		/* operation arguments */
1348{
1349	struct xfs_da_geometry	*geo = args->geo;
1350	__be16			*bestsp;	/* leaf block best freespace */
1351	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
1352	xfs_dir2_db_t		db;		/* data block number */
1353	struct xfs_buf		*dbp;		/* data block buffer */
1354	xfs_dir2_data_entry_t	*dep;		/* data entry structure */
1355	xfs_inode_t		*dp;		/* incore directory inode */
1356	int			error;		/* error return code */
1357	xfs_dir2_db_t		i;		/* temporary data block # */
1358	int			index;		/* index into leaf entries */
1359	struct xfs_buf		*lbp;		/* leaf buffer */
1360	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1361	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1362	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
1363	int			needlog;	/* need to log data header */
1364	int			needscan;	/* need to rescan data frees */
1365	xfs_dir2_data_off_t	oldbest;	/* old value of best free */
1366	struct xfs_dir2_data_free *bf;		/* bestfree table */
1367	struct xfs_dir3_icleaf_hdr leafhdr;
1368
1369	trace_xfs_dir2_leaf_removename(args);
1370
1371	/*
1372	 * Lookup the leaf entry, get the leaf and data blocks read in.
1373	 */
1374	error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp, &leafhdr);
1375	if (error)
1376		return error;
1377
1378	dp = args->dp;
1379	leaf = lbp->b_addr;
1380	hdr = dbp->b_addr;
1381	xfs_dir3_data_check(dp, dbp);
1382	bf = xfs_dir2_data_bestfree_p(dp->i_mount, hdr);
1383
1384	/*
1385	 * Point to the leaf entry, use that to point to the data entry.
1386	 */
1387	lep = &leafhdr.ents[index];
1388	db = xfs_dir2_dataptr_to_db(geo, be32_to_cpu(lep->address));
1389	dep = (xfs_dir2_data_entry_t *)((char *)hdr +
1390		xfs_dir2_dataptr_to_off(geo, be32_to_cpu(lep->address)));
1391	needscan = needlog = 0;
1392	oldbest = be16_to_cpu(bf[0].length);
1393	ltp = xfs_dir2_leaf_tail_p(geo, leaf);
1394	bestsp = xfs_dir2_leaf_bests_p(ltp);
1395	if (be16_to_cpu(bestsp[db]) != oldbest) {
1396		xfs_buf_mark_corrupt(lbp);
1397		xfs_da_mark_sick(args);
1398		return -EFSCORRUPTED;
1399	}
1400
1401	/*
1402	 * Mark the former data entry unused.
1403	 */
1404	xfs_dir2_data_make_free(args, dbp,
1405		(xfs_dir2_data_aoff_t)((char *)dep - (char *)hdr),
1406		xfs_dir2_data_entsize(dp->i_mount, dep->namelen), &needlog,
1407		&needscan);
1408	/*
1409	 * We just mark the leaf entry stale by putting a null in it.
1410	 */
1411	leafhdr.stale++;
1412	xfs_dir2_leaf_hdr_to_disk(dp->i_mount, leaf, &leafhdr);
1413	xfs_dir3_leaf_log_header(args, lbp);
1414
1415	lep->address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
1416	xfs_dir3_leaf_log_ents(args, &leafhdr, lbp, index, index);
1417
1418	/*
1419	 * Scan the freespace in the data block again if necessary,
1420	 * log the data block header if necessary.
1421	 */
1422	if (needscan)
1423		xfs_dir2_data_freescan(dp->i_mount, hdr, &needlog);
1424	if (needlog)
1425		xfs_dir2_data_log_header(args, dbp);
1426	/*
1427	 * If the longest freespace in the data block has changed,
1428	 * put the new value in the bests table and log that.
1429	 */
1430	if (be16_to_cpu(bf[0].length) != oldbest) {
1431		bestsp[db] = bf[0].length;
1432		xfs_dir3_leaf_log_bests(args, lbp, db, db);
1433	}
1434	xfs_dir3_data_check(dp, dbp);
1435	/*
1436	 * If the data block is now empty then get rid of the data block.
1437	 */
1438	if (be16_to_cpu(bf[0].length) ==
1439	    geo->blksize - geo->data_entry_offset) {
1440		ASSERT(db != geo->datablk);
1441		if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
1442			/*
1443			 * Nope, can't get rid of it because it caused
1444			 * allocation of a bmap btree block to do so.
1445			 * Just go on, returning success, leaving the
1446			 * empty block in place.
1447			 */
1448			if (error == -ENOSPC && args->total == 0)
1449				error = 0;
1450			xfs_dir3_leaf_check(dp, lbp);
1451			return error;
1452		}
1453		dbp = NULL;
1454		/*
1455		 * If this is the last data block then compact the
1456		 * bests table by getting rid of entries.
1457		 */
1458		if (db == be32_to_cpu(ltp->bestcount) - 1) {
1459			/*
1460			 * Look for the last active entry (i).
1461			 */
1462			for (i = db - 1; i > 0; i--) {
1463				if (bestsp[i] != cpu_to_be16(NULLDATAOFF))
1464					break;
1465			}
1466			/*
1467			 * Copy the table down so inactive entries at the
1468			 * end are removed.
1469			 */
1470			memmove(&bestsp[db - i], bestsp,
1471				(be32_to_cpu(ltp->bestcount) - (db - i)) * sizeof(*bestsp));
1472			be32_add_cpu(&ltp->bestcount, -(db - i));
1473			xfs_dir3_leaf_log_tail(args, lbp);
1474			xfs_dir3_leaf_log_bests(args, lbp, 0,
1475						be32_to_cpu(ltp->bestcount) - 1);
1476		} else
1477			bestsp[db] = cpu_to_be16(NULLDATAOFF);
1478	}
1479	/*
1480	 * If the data block was not the first one, drop it.
1481	 */
1482	else if (db != geo->datablk)
1483		dbp = NULL;
1484
1485	xfs_dir3_leaf_check(dp, lbp);
1486	/*
1487	 * See if we can convert to block form.
1488	 */
1489	return xfs_dir2_leaf_to_block(args, lbp, dbp);
1490}
1491
1492/*
1493 * Replace the inode number in a leaf format directory entry.
1494 */
1495int						/* error */
1496xfs_dir2_leaf_replace(
1497	xfs_da_args_t		*args)		/* operation arguments */
1498{
1499	struct xfs_buf		*dbp;		/* data block buffer */
1500	xfs_dir2_data_entry_t	*dep;		/* data block entry */
1501	xfs_inode_t		*dp;		/* incore directory inode */
1502	int			error;		/* error return code */
1503	int			index;		/* index of leaf entry */
1504	struct xfs_buf		*lbp;		/* leaf buffer */
1505	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1506	xfs_trans_t		*tp;		/* transaction pointer */
1507	struct xfs_dir3_icleaf_hdr leafhdr;
1508
1509	trace_xfs_dir2_leaf_replace(args);
1510
1511	/*
1512	 * Look up the entry.
1513	 */
1514	error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp, &leafhdr);
1515	if (error)
1516		return error;
1517
1518	dp = args->dp;
1519	/*
1520	 * Point to the leaf entry, get data address from it.
1521	 */
1522	lep = &leafhdr.ents[index];
1523	/*
1524	 * Point to the data entry.
1525	 */
1526	dep = (xfs_dir2_data_entry_t *)
1527	      ((char *)dbp->b_addr +
1528	       xfs_dir2_dataptr_to_off(args->geo, be32_to_cpu(lep->address)));
1529	ASSERT(args->inumber != be64_to_cpu(dep->inumber));
1530	/*
1531	 * Put the new inode number in, log it.
1532	 */
1533	dep->inumber = cpu_to_be64(args->inumber);
1534	xfs_dir2_data_put_ftype(dp->i_mount, dep, args->filetype);
1535	tp = args->trans;
1536	xfs_dir2_data_log_entry(args, dbp, dep);
1537	xfs_dir3_leaf_check(dp, lbp);
1538	xfs_trans_brelse(tp, lbp);
1539	return 0;
1540}
1541
1542/*
1543 * Return index in the leaf block (lbp) which is either the first
1544 * one with this hash value, or if there are none, the insert point
1545 * for that hash value.
1546 */
1547int						/* index value */
1548xfs_dir2_leaf_search_hash(
1549	xfs_da_args_t		*args,		/* operation arguments */
1550	struct xfs_buf		*lbp)		/* leaf buffer */
1551{
1552	xfs_dahash_t		hash=0;		/* hash from this entry */
1553	xfs_dahash_t		hashwant;	/* hash value looking for */
1554	int			high;		/* high leaf index */
1555	int			low;		/* low leaf index */
1556	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1557	int			mid=0;		/* current leaf index */
1558	struct xfs_dir3_icleaf_hdr leafhdr;
1559
1560	xfs_dir2_leaf_hdr_from_disk(args->dp->i_mount, &leafhdr, lbp->b_addr);
1561
1562	/*
1563	 * Note, the table cannot be empty, so we have to go through the loop.
1564	 * Binary search the leaf entries looking for our hash value.
1565	 */
1566	for (lep = leafhdr.ents, low = 0, high = leafhdr.count - 1,
1567		hashwant = args->hashval;
1568	     low <= high; ) {
1569		mid = (low + high) >> 1;
1570		if ((hash = be32_to_cpu(lep[mid].hashval)) == hashwant)
1571			break;
1572		if (hash < hashwant)
1573			low = mid + 1;
1574		else
1575			high = mid - 1;
1576	}
1577	/*
1578	 * Found one, back up through all the equal hash values.
1579	 */
1580	if (hash == hashwant) {
1581		while (mid > 0 && be32_to_cpu(lep[mid - 1].hashval) == hashwant) {
1582			mid--;
1583		}
1584	}
1585	/*
1586	 * Need to point to an entry higher than ours.
1587	 */
1588	else if (hash < hashwant)
1589		mid++;
1590	return mid;
1591}
1592
1593/*
1594 * Trim off a trailing data block.  We know it's empty since the leaf
1595 * freespace table says so.
1596 */
1597int						/* error */
1598xfs_dir2_leaf_trim_data(
1599	xfs_da_args_t		*args,		/* operation arguments */
1600	struct xfs_buf		*lbp,		/* leaf buffer */
1601	xfs_dir2_db_t		db)		/* data block number */
1602{
1603	struct xfs_da_geometry	*geo = args->geo;
1604	__be16			*bestsp;	/* leaf bests table */
1605	struct xfs_buf		*dbp;		/* data block buffer */
1606	xfs_inode_t		*dp;		/* incore directory inode */
1607	int			error;		/* error return value */
1608	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1609	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
1610	xfs_trans_t		*tp;		/* transaction pointer */
1611
1612	dp = args->dp;
1613	tp = args->trans;
1614	/*
1615	 * Read the offending data block.  We need its buffer.
1616	 */
1617	error = xfs_dir3_data_read(tp, dp, xfs_dir2_db_to_da(geo, db), 0, &dbp);
1618	if (error)
1619		return error;
1620
1621	leaf = lbp->b_addr;
1622	ltp = xfs_dir2_leaf_tail_p(geo, leaf);
1623
1624#ifdef DEBUG
1625{
1626	struct xfs_dir2_data_hdr *hdr = dbp->b_addr;
1627	struct xfs_dir2_data_free *bf =
1628		xfs_dir2_data_bestfree_p(dp->i_mount, hdr);
1629
1630	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
1631	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC));
1632	ASSERT(be16_to_cpu(bf[0].length) ==
1633	       geo->blksize - geo->data_entry_offset);
1634	ASSERT(db == be32_to_cpu(ltp->bestcount) - 1);
1635}
1636#endif
1637
1638	/*
1639	 * Get rid of the data block.
1640	 */
1641	if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
1642		ASSERT(error != -ENOSPC);
1643		xfs_trans_brelse(tp, dbp);
1644		return error;
1645	}
1646	/*
1647	 * Eliminate the last bests entry from the table.
1648	 */
1649	bestsp = xfs_dir2_leaf_bests_p(ltp);
1650	be32_add_cpu(&ltp->bestcount, -1);
1651	memmove(&bestsp[1], &bestsp[0], be32_to_cpu(ltp->bestcount) * sizeof(*bestsp));
1652	xfs_dir3_leaf_log_tail(args, lbp);
1653	xfs_dir3_leaf_log_bests(args, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1654	return 0;
1655}
1656
1657static inline size_t
1658xfs_dir3_leaf_size(
1659	struct xfs_dir3_icleaf_hdr	*hdr,
1660	int				counts)
1661{
1662	int	entries;
1663	int	hdrsize;
1664
1665	entries = hdr->count - hdr->stale;
1666	if (hdr->magic == XFS_DIR2_LEAF1_MAGIC ||
1667	    hdr->magic == XFS_DIR2_LEAFN_MAGIC)
1668		hdrsize = sizeof(struct xfs_dir2_leaf_hdr);
1669	else
1670		hdrsize = sizeof(struct xfs_dir3_leaf_hdr);
1671
1672	return hdrsize + entries * sizeof(xfs_dir2_leaf_entry_t)
1673	               + counts * sizeof(xfs_dir2_data_off_t)
1674		       + sizeof(xfs_dir2_leaf_tail_t);
1675}
1676
1677/*
1678 * Convert node form directory to leaf form directory.
1679 * The root of the node form dir needs to already be a LEAFN block.
1680 * Just return if we can't do anything.
1681 */
1682int						/* error */
1683xfs_dir2_node_to_leaf(
1684	xfs_da_state_t		*state)		/* directory operation state */
1685{
1686	xfs_da_args_t		*args;		/* operation arguments */
1687	xfs_inode_t		*dp;		/* incore directory inode */
1688	int			error;		/* error return code */
1689	struct xfs_buf		*fbp;		/* buffer for freespace block */
1690	xfs_fileoff_t		fo;		/* freespace file offset */
1691	struct xfs_buf		*lbp;		/* buffer for leaf block */
1692	xfs_dir2_leaf_tail_t	*ltp;		/* tail of leaf structure */
1693	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1694	xfs_mount_t		*mp;		/* filesystem mount point */
1695	int			rval;		/* successful free trim? */
1696	xfs_trans_t		*tp;		/* transaction pointer */
1697	struct xfs_dir3_icleaf_hdr leafhdr;
1698	struct xfs_dir3_icfree_hdr freehdr;
1699
1700	/*
1701	 * There's more than a leaf level in the btree, so there must
1702	 * be multiple leafn blocks.  Give up.
1703	 */
1704	if (state->path.active > 1)
1705		return 0;
1706	args = state->args;
1707
1708	trace_xfs_dir2_node_to_leaf(args);
1709
1710	mp = state->mp;
1711	dp = args->dp;
1712	tp = args->trans;
1713	/*
1714	 * Get the last offset in the file.
1715	 */
1716	if ((error = xfs_bmap_last_offset(dp, &fo, XFS_DATA_FORK))) {
1717		return error;
1718	}
1719	fo -= args->geo->fsbcount;
1720	/*
1721	 * If there are freespace blocks other than the first one,
1722	 * take this opportunity to remove trailing empty freespace blocks
1723	 * that may have been left behind during no-space-reservation
1724	 * operations.
1725	 */
1726	while (fo > args->geo->freeblk) {
1727		if ((error = xfs_dir2_node_trim_free(args, fo, &rval))) {
1728			return error;
1729		}
1730		if (rval)
1731			fo -= args->geo->fsbcount;
1732		else
1733			return 0;
1734	}
1735	/*
1736	 * Now find the block just before the freespace block.
1737	 */
1738	if ((error = xfs_bmap_last_before(tp, dp, &fo, XFS_DATA_FORK))) {
1739		return error;
1740	}
1741	/*
1742	 * If it's not the single leaf block, give up.
1743	 */
1744	if (XFS_FSB_TO_B(mp, fo) > XFS_DIR2_LEAF_OFFSET + args->geo->blksize)
1745		return 0;
1746	lbp = state->path.blk[0].bp;
1747	leaf = lbp->b_addr;
1748	xfs_dir2_leaf_hdr_from_disk(mp, &leafhdr, leaf);
1749
1750	ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
1751	       leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
1752
1753	/*
1754	 * Read the freespace block.
1755	 */
1756	error = xfs_dir2_free_read(tp, dp,  args->geo->freeblk, &fbp);
1757	if (error)
1758		return error;
1759	xfs_dir2_free_hdr_from_disk(mp, &freehdr, fbp->b_addr);
1760
1761	ASSERT(!freehdr.firstdb);
1762
1763	/*
1764	 * Now see if the leafn and free data will fit in a leaf1.
1765	 * If not, release the buffer and give up.
1766	 */
1767	if (xfs_dir3_leaf_size(&leafhdr, freehdr.nvalid) > args->geo->blksize) {
1768		xfs_trans_brelse(tp, fbp);
1769		return 0;
1770	}
1771
1772	/*
1773	 * If the leaf has any stale entries in it, compress them out.
1774	 */
1775	if (leafhdr.stale)
1776		xfs_dir3_leaf_compact(args, &leafhdr, lbp);
1777
1778	lbp->b_ops = &xfs_dir3_leaf1_buf_ops;
1779	xfs_trans_buf_set_type(tp, lbp, XFS_BLFT_DIR_LEAF1_BUF);
1780	leafhdr.magic = (leafhdr.magic == XFS_DIR2_LEAFN_MAGIC)
1781					? XFS_DIR2_LEAF1_MAGIC
1782					: XFS_DIR3_LEAF1_MAGIC;
1783
1784	/*
1785	 * Set up the leaf tail from the freespace block.
1786	 */
1787	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
1788	ltp->bestcount = cpu_to_be32(freehdr.nvalid);
1789
1790	/*
1791	 * Set up the leaf bests table.
1792	 */
1793	memcpy(xfs_dir2_leaf_bests_p(ltp), freehdr.bests,
1794		freehdr.nvalid * sizeof(xfs_dir2_data_off_t));
1795
1796	xfs_dir2_leaf_hdr_to_disk(mp, leaf, &leafhdr);
1797	xfs_dir3_leaf_log_header(args, lbp);
1798	xfs_dir3_leaf_log_bests(args, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1799	xfs_dir3_leaf_log_tail(args, lbp);
1800	xfs_dir3_leaf_check(dp, lbp);
1801
1802	/*
1803	 * Get rid of the freespace block.
1804	 */
1805	error = xfs_dir2_shrink_inode(args,
1806			xfs_dir2_byte_to_db(args->geo, XFS_DIR2_FREE_OFFSET),
1807			fbp);
1808	if (error) {
1809		/*
1810		 * This can't fail here because it can only happen when
1811		 * punching out the middle of an extent, and this is an
1812		 * isolated block.
1813		 */
1814		ASSERT(error != -ENOSPC);
1815		return error;
1816	}
1817	fbp = NULL;
1818	/*
1819	 * Now see if we can convert the single-leaf directory
1820	 * down to a block form directory.
1821	 * This routine always kills the dabuf for the leaf, so
1822	 * eliminate it from the path.
1823	 */
1824	error = xfs_dir2_leaf_to_block(args, lbp, NULL);
1825	state->path.blk[0].bp = NULL;
1826	return error;
1827}