1/*
   2 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
   3 * Copyright (c) 2013 Red Hat, Inc.
   4 * All Rights Reserved.
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License as
   8 * published by the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope that it would be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write the Free Software Foundation,
  17 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18 */
  19#include "xfs.h"
  20#include "xfs_fs.h"
 
  21#include "xfs_format.h"
  22#include "xfs_log_format.h"
  23#include "xfs_trans_resv.h"
  24#include "xfs_mount.h"
  25#include "xfs_da_format.h"
  26#include "xfs_da_btree.h"
  27#include "xfs_inode.h"
  28#include "xfs_bmap.h"
  29#include "xfs_dir2.h"
  30#include "xfs_dir2_priv.h"
  31#include "xfs_error.h"
  32#include "xfs_trace.h"
  33#include "xfs_trans.h"
  34#include "xfs_buf_item.h"
  35#include "xfs_cksum.h"
  36#include "xfs_log.h"
  37
  38/*
  39 * Local function declarations.
  40 */
  41static int xfs_dir2_leaf_lookup_int(xfs_da_args_t *args, struct xfs_buf **lbpp,
  42				    int *indexp, struct xfs_buf **dbpp);
  43static void xfs_dir3_leaf_log_bests(struct xfs_da_args *args,
  44				    struct xfs_buf *bp, int first, int last);
  45static void xfs_dir3_leaf_log_tail(struct xfs_da_args *args,
  46				   struct xfs_buf *bp);
  47
  48/*
  49 * Check the internal consistency of a leaf1 block.
  50 * Pop an assert if something is wrong.
  51 */
  52#ifdef DEBUG
  53static xfs_failaddr_t
  54xfs_dir3_leaf1_check(
  55	struct xfs_inode	*dp,
  56	struct xfs_buf		*bp)
  57{
  58	struct xfs_dir2_leaf	*leaf = bp->b_addr;
  59	struct xfs_dir3_icleaf_hdr leafhdr;
  60
  61	dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
  62
  63	if (leafhdr.magic == XFS_DIR3_LEAF1_MAGIC) {
  64		struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr;
  65		if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn)
  66			return __this_address;
  67	} else if (leafhdr.magic != XFS_DIR2_LEAF1_MAGIC)
  68		return __this_address;
  69
  70	return xfs_dir3_leaf_check_int(dp->i_mount, dp, &leafhdr, leaf);
  71}
  72
  73static inline void
  74xfs_dir3_leaf_check(
  75	struct xfs_inode	*dp,
  76	struct xfs_buf		*bp)
  77{
  78	xfs_failaddr_t		fa;
  79
  80	fa = xfs_dir3_leaf1_check(dp, bp);
  81	if (!fa)
  82		return;
  83	xfs_corruption_error(__func__, XFS_ERRLEVEL_LOW, dp->i_mount,
  84			bp->b_addr, __FILE__, __LINE__, fa);
 
  85	ASSERT(0);
  86}
  87#else
  88#define	xfs_dir3_leaf_check(dp, bp)
  89#endif
  90
  91xfs_failaddr_t
  92xfs_dir3_leaf_check_int(
  93	struct xfs_mount	*mp,
  94	struct xfs_inode	*dp,
  95	struct xfs_dir3_icleaf_hdr *hdr,
  96	struct xfs_dir2_leaf	*leaf)
  97{
  98	struct xfs_dir2_leaf_entry *ents;
  99	xfs_dir2_leaf_tail_t	*ltp;
 100	int			stale;
 101	int			i;
 102	const struct xfs_dir_ops *ops;
 103	struct xfs_dir3_icleaf_hdr leafhdr;
 104	struct xfs_da_geometry	*geo = mp->m_dir_geo;
 105
 106	/*
 107	 * we can be passed a null dp here from a verifier, so we need to go the
 108	 * hard way to get them.
 109	 */
 110	ops = xfs_dir_get_ops(mp, dp);
 111
 112	if (!hdr) {
 113		ops->leaf_hdr_from_disk(&leafhdr, leaf);
 114		hdr = &leafhdr;
 115	}
 116
 117	ents = ops->leaf_ents_p(leaf);
 118	ltp = xfs_dir2_leaf_tail_p(geo, leaf);
 119
 120	/*
 121	 * XXX (dgc): This value is not restrictive enough.
 122	 * Should factor in the size of the bests table as well.
 123	 * We can deduce a value for that from di_size.
 124	 */
 125	if (hdr->count > ops->leaf_max_ents(geo))
 126		return __this_address;
 127
 128	/* Leaves and bests don't overlap in leaf format. */
 129	if ((hdr->magic == XFS_DIR2_LEAF1_MAGIC ||
 130	     hdr->magic == XFS_DIR3_LEAF1_MAGIC) &&
 131	    (char *)&ents[hdr->count] > (char *)xfs_dir2_leaf_bests_p(ltp))
 132		return __this_address;
 133
 134	/* Check hash value order, count stale entries.  */
 135	for (i = stale = 0; i < hdr->count; i++) {
 136		if (i + 1 < hdr->count) {
 137			if (be32_to_cpu(ents[i].hashval) >
 138					be32_to_cpu(ents[i + 1].hashval))
 139				return __this_address;
 140		}
 141		if (ents[i].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 142			stale++;
 143	}
 144	if (hdr->stale != stale)
 145		return __this_address;
 146	return NULL;
 147}
 148
 149/*
 150 * We verify the magic numbers before decoding the leaf header so that on debug
 151 * kernels we don't get assertion failures in xfs_dir3_leaf_hdr_from_disk() due
 152 * to incorrect magic numbers.
 153 */
 154static xfs_failaddr_t
 155xfs_dir3_leaf_verify(
 156	struct xfs_buf		*bp,
 157	uint16_t		magic)
 158{
 159	struct xfs_mount	*mp = bp->b_target->bt_mount;
 160	struct xfs_dir2_leaf	*leaf = bp->b_addr;
 
 161
 162	ASSERT(magic == XFS_DIR2_LEAF1_MAGIC || magic == XFS_DIR2_LEAFN_MAGIC);
 163
 164	if (xfs_sb_version_hascrc(&mp->m_sb)) {
 165		struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr;
 166		uint16_t		magic3;
 167
 168		magic3 = (magic == XFS_DIR2_LEAF1_MAGIC) ? XFS_DIR3_LEAF1_MAGIC
 169							 : XFS_DIR3_LEAFN_MAGIC;
 170
 171		if (leaf3->info.hdr.magic != cpu_to_be16(magic3))
 172			return __this_address;
 173		if (!uuid_equal(&leaf3->info.uuid, &mp->m_sb.sb_meta_uuid))
 174			return __this_address;
 175		if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn)
 176			return __this_address;
 177		if (!xfs_log_check_lsn(mp, be64_to_cpu(leaf3->info.lsn)))
 178			return __this_address;
 179	} else {
 180		if (leaf->hdr.info.magic != cpu_to_be16(magic))
 181			return __this_address;
 182	}
 183
 184	return xfs_dir3_leaf_check_int(mp, NULL, NULL, leaf);
 185}
 186
 187static void
 188__read_verify(
 189	struct xfs_buf  *bp,
 190	uint16_t	magic)
 191{
 192	struct xfs_mount	*mp = bp->b_target->bt_mount;
 193	xfs_failaddr_t		fa;
 194
 195	if (xfs_sb_version_hascrc(&mp->m_sb) &&
 196	     !xfs_buf_verify_cksum(bp, XFS_DIR3_LEAF_CRC_OFF))
 197		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 198	else {
 199		fa = xfs_dir3_leaf_verify(bp, magic);
 200		if (fa)
 201			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 202	}
 203}
 204
 205static void
 206__write_verify(
 207	struct xfs_buf  *bp,
 208	uint16_t	magic)
 209{
 210	struct xfs_mount	*mp = bp->b_target->bt_mount;
 211	struct xfs_buf_log_item	*bip = bp->b_log_item;
 212	struct xfs_dir3_leaf_hdr *hdr3 = bp->b_addr;
 213	xfs_failaddr_t		fa;
 214
 215	fa = xfs_dir3_leaf_verify(bp, magic);
 216	if (fa) {
 217		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 218		return;
 219	}
 220
 221	if (!xfs_sb_version_hascrc(&mp->m_sb))
 222		return;
 223
 224	if (bip)
 225		hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
 226
 227	xfs_buf_update_cksum(bp, XFS_DIR3_LEAF_CRC_OFF);
 228}
 229
 230static xfs_failaddr_t
 231xfs_dir3_leaf1_verify(
 232	struct xfs_buf	*bp)
 233{
 234	return xfs_dir3_leaf_verify(bp, XFS_DIR2_LEAF1_MAGIC);
 235}
 236
 237static void
 238xfs_dir3_leaf1_read_verify(
 239	struct xfs_buf	*bp)
 240{
 241	__read_verify(bp, XFS_DIR2_LEAF1_MAGIC);
 242}
 243
 244static void
 245xfs_dir3_leaf1_write_verify(
 246	struct xfs_buf	*bp)
 247{
 248	__write_verify(bp, XFS_DIR2_LEAF1_MAGIC);
 249}
 250
 251static xfs_failaddr_t
 252xfs_dir3_leafn_verify(
 253	struct xfs_buf	*bp)
 254{
 255	return xfs_dir3_leaf_verify(bp, XFS_DIR2_LEAFN_MAGIC);
 256}
 257
 258static void
 259xfs_dir3_leafn_read_verify(
 260	struct xfs_buf	*bp)
 261{
 262	__read_verify(bp, XFS_DIR2_LEAFN_MAGIC);
 263}
 264
 265static void
 266xfs_dir3_leafn_write_verify(
 267	struct xfs_buf	*bp)
 268{
 269	__write_verify(bp, XFS_DIR2_LEAFN_MAGIC);
 270}
 271
 272const struct xfs_buf_ops xfs_dir3_leaf1_buf_ops = {
 273	.name = "xfs_dir3_leaf1",
 274	.verify_read = xfs_dir3_leaf1_read_verify,
 275	.verify_write = xfs_dir3_leaf1_write_verify,
 276	.verify_struct = xfs_dir3_leaf1_verify,
 
 
 277};
 278
 279const struct xfs_buf_ops xfs_dir3_leafn_buf_ops = {
 280	.name = "xfs_dir3_leafn",
 281	.verify_read = xfs_dir3_leafn_read_verify,
 282	.verify_write = xfs_dir3_leafn_write_verify,
 283	.verify_struct = xfs_dir3_leafn_verify,
 
 
 284};
 285
 286int
 287xfs_dir3_leaf_read(
 288	struct xfs_trans	*tp,
 289	struct xfs_inode	*dp,
 290	xfs_dablk_t		fbno,
 291	xfs_daddr_t		mappedbno,
 292	struct xfs_buf		**bpp)
 293{
 294	int			err;
 295
 296	err = xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp,
 297				XFS_DATA_FORK, &xfs_dir3_leaf1_buf_ops);
 298	if (!err && tp && *bpp)
 299		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_LEAF1_BUF);
 300	return err;
 301}
 302
 303int
 304xfs_dir3_leafn_read(
 305	struct xfs_trans	*tp,
 306	struct xfs_inode	*dp,
 307	xfs_dablk_t		fbno,
 308	xfs_daddr_t		mappedbno,
 309	struct xfs_buf		**bpp)
 310{
 311	int			err;
 312
 313	err = xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp,
 314				XFS_DATA_FORK, &xfs_dir3_leafn_buf_ops);
 315	if (!err && tp && *bpp)
 316		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_LEAFN_BUF);
 317	return err;
 318}
 319
 320/*
 321 * Initialize a new leaf block, leaf1 or leafn magic accepted.
 322 */
 323static void
 324xfs_dir3_leaf_init(
 325	struct xfs_mount	*mp,
 326	struct xfs_trans	*tp,
 327	struct xfs_buf		*bp,
 328	xfs_ino_t		owner,
 329	uint16_t		type)
 330{
 331	struct xfs_dir2_leaf	*leaf = bp->b_addr;
 332
 333	ASSERT(type == XFS_DIR2_LEAF1_MAGIC || type == XFS_DIR2_LEAFN_MAGIC);
 334
 335	if (xfs_sb_version_hascrc(&mp->m_sb)) {
 336		struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr;
 337
 338		memset(leaf3, 0, sizeof(*leaf3));
 339
 340		leaf3->info.hdr.magic = (type == XFS_DIR2_LEAF1_MAGIC)
 341					 ? cpu_to_be16(XFS_DIR3_LEAF1_MAGIC)
 342					 : cpu_to_be16(XFS_DIR3_LEAFN_MAGIC);
 343		leaf3->info.blkno = cpu_to_be64(bp->b_bn);
 344		leaf3->info.owner = cpu_to_be64(owner);
 345		uuid_copy(&leaf3->info.uuid, &mp->m_sb.sb_meta_uuid);
 346	} else {
 347		memset(leaf, 0, sizeof(*leaf));
 348		leaf->hdr.info.magic = cpu_to_be16(type);
 349	}
 350
 351	/*
 352	 * If it's a leaf-format directory initialize the tail.
 353	 * Caller is responsible for initialising the bests table.
 354	 */
 355	if (type == XFS_DIR2_LEAF1_MAGIC) {
 356		struct xfs_dir2_leaf_tail *ltp;
 357
 358		ltp = xfs_dir2_leaf_tail_p(mp->m_dir_geo, leaf);
 359		ltp->bestcount = 0;
 360		bp->b_ops = &xfs_dir3_leaf1_buf_ops;
 361		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAF1_BUF);
 362	} else {
 363		bp->b_ops = &xfs_dir3_leafn_buf_ops;
 364		xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
 365	}
 366}
 367
 368int
 369xfs_dir3_leaf_get_buf(
 370	xfs_da_args_t		*args,
 371	xfs_dir2_db_t		bno,
 372	struct xfs_buf		**bpp,
 373	uint16_t		magic)
 374{
 375	struct xfs_inode	*dp = args->dp;
 376	struct xfs_trans	*tp = args->trans;
 377	struct xfs_mount	*mp = dp->i_mount;
 378	struct xfs_buf		*bp;
 379	int			error;
 380
 381	ASSERT(magic == XFS_DIR2_LEAF1_MAGIC || magic == XFS_DIR2_LEAFN_MAGIC);
 382	ASSERT(bno >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET) &&
 383	       bno < xfs_dir2_byte_to_db(args->geo, XFS_DIR2_FREE_OFFSET));
 384
 385	error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(args->geo, bno),
 386			       -1, &bp, XFS_DATA_FORK);
 387	if (error)
 388		return error;
 389
 390	xfs_dir3_leaf_init(mp, tp, bp, dp->i_ino, magic);
 391	xfs_dir3_leaf_log_header(args, bp);
 392	if (magic == XFS_DIR2_LEAF1_MAGIC)
 393		xfs_dir3_leaf_log_tail(args, bp);
 394	*bpp = bp;
 395	return 0;
 396}
 397
 398/*
 399 * Convert a block form directory to a leaf form directory.
 400 */
 401int						/* error */
 402xfs_dir2_block_to_leaf(
 403	xfs_da_args_t		*args,		/* operation arguments */
 404	struct xfs_buf		*dbp)		/* input block's buffer */
 405{
 406	__be16			*bestsp;	/* leaf's bestsp entries */
 407	xfs_dablk_t		blkno;		/* leaf block's bno */
 408	xfs_dir2_data_hdr_t	*hdr;		/* block header */
 409	xfs_dir2_leaf_entry_t	*blp;		/* block's leaf entries */
 410	xfs_dir2_block_tail_t	*btp;		/* block's tail */
 411	xfs_inode_t		*dp;		/* incore directory inode */
 412	int			error;		/* error return code */
 413	struct xfs_buf		*lbp;		/* leaf block's buffer */
 414	xfs_dir2_db_t		ldb;		/* leaf block's bno */
 415	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
 416	xfs_dir2_leaf_tail_t	*ltp;		/* leaf's tail */
 417	int			needlog;	/* need to log block header */
 418	int			needscan;	/* need to rescan bestfree */
 419	xfs_trans_t		*tp;		/* transaction pointer */
 420	struct xfs_dir2_data_free *bf;
 421	struct xfs_dir2_leaf_entry *ents;
 422	struct xfs_dir3_icleaf_hdr leafhdr;
 423
 424	trace_xfs_dir2_block_to_leaf(args);
 425
 426	dp = args->dp;
 427	tp = args->trans;
 428	/*
 429	 * Add the leaf block to the inode.
 430	 * This interface will only put blocks in the leaf/node range.
 431	 * Since that's empty now, we'll get the root (block 0 in range).
 432	 */
 433	if ((error = xfs_da_grow_inode(args, &blkno))) {
 434		return error;
 435	}
 436	ldb = xfs_dir2_da_to_db(args->geo, blkno);
 437	ASSERT(ldb == xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET));
 438	/*
 439	 * Initialize the leaf block, get a buffer for it.
 440	 */
 441	error = xfs_dir3_leaf_get_buf(args, ldb, &lbp, XFS_DIR2_LEAF1_MAGIC);
 442	if (error)
 443		return error;
 444
 445	leaf = lbp->b_addr;
 446	hdr = dbp->b_addr;
 447	xfs_dir3_data_check(dp, dbp);
 448	btp = xfs_dir2_block_tail_p(args->geo, hdr);
 449	blp = xfs_dir2_block_leaf_p(btp);
 450	bf = dp->d_ops->data_bestfree_p(hdr);
 451	ents = dp->d_ops->leaf_ents_p(leaf);
 452
 453	/*
 454	 * Set the counts in the leaf header.
 455	 */
 456	dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
 457	leafhdr.count = be32_to_cpu(btp->count);
 458	leafhdr.stale = be32_to_cpu(btp->stale);
 459	dp->d_ops->leaf_hdr_to_disk(leaf, &leafhdr);
 460	xfs_dir3_leaf_log_header(args, lbp);
 461
 462	/*
 463	 * Could compact these but I think we always do the conversion
 464	 * after squeezing out stale entries.
 465	 */
 466	memcpy(ents, blp, be32_to_cpu(btp->count) * sizeof(xfs_dir2_leaf_entry_t));
 467	xfs_dir3_leaf_log_ents(args, lbp, 0, leafhdr.count - 1);
 468	needscan = 0;
 469	needlog = 1;
 470	/*
 471	 * Make the space formerly occupied by the leaf entries and block
 472	 * tail be free.
 473	 */
 474	xfs_dir2_data_make_free(args, dbp,
 475		(xfs_dir2_data_aoff_t)((char *)blp - (char *)hdr),
 476		(xfs_dir2_data_aoff_t)((char *)hdr + args->geo->blksize -
 477				       (char *)blp),
 478		&needlog, &needscan);
 479	/*
 480	 * Fix up the block header, make it a data block.
 481	 */
 482	dbp->b_ops = &xfs_dir3_data_buf_ops;
 483	xfs_trans_buf_set_type(tp, dbp, XFS_BLFT_DIR_DATA_BUF);
 484	if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC))
 485		hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 486	else
 487		hdr->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
 488
 489	if (needscan)
 490		xfs_dir2_data_freescan(dp, hdr, &needlog);
 491	/*
 492	 * Set up leaf tail and bests table.
 493	 */
 494	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
 495	ltp->bestcount = cpu_to_be32(1);
 496	bestsp = xfs_dir2_leaf_bests_p(ltp);
 497	bestsp[0] =  bf[0].length;
 498	/*
 499	 * Log the data header and leaf bests table.
 500	 */
 501	if (needlog)
 502		xfs_dir2_data_log_header(args, dbp);
 503	xfs_dir3_leaf_check(dp, lbp);
 504	xfs_dir3_data_check(dp, dbp);
 505	xfs_dir3_leaf_log_bests(args, lbp, 0, 0);
 506	return 0;
 507}
 508
 509STATIC void
 510xfs_dir3_leaf_find_stale(
 511	struct xfs_dir3_icleaf_hdr *leafhdr,
 512	struct xfs_dir2_leaf_entry *ents,
 513	int			index,
 514	int			*lowstale,
 515	int			*highstale)
 516{
 517	/*
 518	 * Find the first stale entry before our index, if any.
 519	 */
 520	for (*lowstale = index - 1; *lowstale >= 0; --*lowstale) {
 521		if (ents[*lowstale].address ==
 522		    cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 523			break;
 524	}
 525
 526	/*
 527	 * Find the first stale entry at or after our index, if any.
 528	 * Stop if the result would require moving more entries than using
 529	 * lowstale.
 530	 */
 531	for (*highstale = index; *highstale < leafhdr->count; ++*highstale) {
 532		if (ents[*highstale].address ==
 533		    cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 534			break;
 535		if (*lowstale >= 0 && index - *lowstale <= *highstale - index)
 536			break;
 537	}
 538}
 539
 540struct xfs_dir2_leaf_entry *
 541xfs_dir3_leaf_find_entry(
 542	struct xfs_dir3_icleaf_hdr *leafhdr,
 543	struct xfs_dir2_leaf_entry *ents,
 544	int			index,		/* leaf table position */
 545	int			compact,	/* need to compact leaves */
 546	int			lowstale,	/* index of prev stale leaf */
 547	int			highstale,	/* index of next stale leaf */
 548	int			*lfloglow,	/* low leaf logging index */
 549	int			*lfloghigh)	/* high leaf logging index */
 550{
 551	if (!leafhdr->stale) {
 552		xfs_dir2_leaf_entry_t	*lep;	/* leaf entry table pointer */
 553
 554		/*
 555		 * Now we need to make room to insert the leaf entry.
 556		 *
 557		 * If there are no stale entries, just insert a hole at index.
 558		 */
 559		lep = &ents[index];
 560		if (index < leafhdr->count)
 561			memmove(lep + 1, lep,
 562				(leafhdr->count - index) * sizeof(*lep));
 563
 564		/*
 565		 * Record low and high logging indices for the leaf.
 566		 */
 567		*lfloglow = index;
 568		*lfloghigh = leafhdr->count++;
 569		return lep;
 570	}
 571
 572	/*
 573	 * There are stale entries.
 574	 *
 575	 * We will use one of them for the new entry.  It's probably not at
 576	 * the right location, so we'll have to shift some up or down first.
 577	 *
 578	 * If we didn't compact before, we need to find the nearest stale
 579	 * entries before and after our insertion point.
 580	 */
 581	if (compact == 0)
 582		xfs_dir3_leaf_find_stale(leafhdr, ents, index,
 583					 &lowstale, &highstale);
 584
 585	/*
 586	 * If the low one is better, use it.
 587	 */
 588	if (lowstale >= 0 &&
 589	    (highstale == leafhdr->count ||
 590	     index - lowstale - 1 < highstale - index)) {
 591		ASSERT(index - lowstale - 1 >= 0);
 592		ASSERT(ents[lowstale].address ==
 593		       cpu_to_be32(XFS_DIR2_NULL_DATAPTR));
 594
 595		/*
 596		 * Copy entries up to cover the stale entry and make room
 597		 * for the new entry.
 598		 */
 599		if (index - lowstale - 1 > 0) {
 600			memmove(&ents[lowstale], &ents[lowstale + 1],
 601				(index - lowstale - 1) *
 602					sizeof(xfs_dir2_leaf_entry_t));
 603		}
 604		*lfloglow = MIN(lowstale, *lfloglow);
 605		*lfloghigh = MAX(index - 1, *lfloghigh);
 606		leafhdr->stale--;
 607		return &ents[index - 1];
 608	}
 609
 610	/*
 611	 * The high one is better, so use that one.
 612	 */
 613	ASSERT(highstale - index >= 0);
 614	ASSERT(ents[highstale].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR));
 615
 616	/*
 617	 * Copy entries down to cover the stale entry and make room for the
 618	 * new entry.
 619	 */
 620	if (highstale - index > 0) {
 621		memmove(&ents[index + 1], &ents[index],
 622			(highstale - index) * sizeof(xfs_dir2_leaf_entry_t));
 623	}
 624	*lfloglow = MIN(index, *lfloglow);
 625	*lfloghigh = MAX(highstale, *lfloghigh);
 626	leafhdr->stale--;
 627	return &ents[index];
 628}
 629
 630/*
 631 * Add an entry to a leaf form directory.
 632 */
 633int						/* error */
 634xfs_dir2_leaf_addname(
 635	xfs_da_args_t		*args)		/* operation arguments */
 636{
 
 
 637	__be16			*bestsp;	/* freespace table in leaf */
 638	int			compact;	/* need to compact leaves */
 639	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
 640	struct xfs_buf		*dbp;		/* data block buffer */
 641	xfs_dir2_data_entry_t	*dep;		/* data block entry */
 642	xfs_inode_t		*dp;		/* incore directory inode */
 643	xfs_dir2_data_unused_t	*dup;		/* data unused entry */
 
 
 
 
 
 
 
 
 644	int			error;		/* error return value */
 645	int			grown;		/* allocated new data block */
 646	int			highstale;	/* index of next stale leaf */
 647	int			i;		/* temporary, index */
 648	int			index;		/* leaf table position */
 649	struct xfs_buf		*lbp;		/* leaf's buffer */
 650	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
 651	int			length;		/* length of new entry */
 652	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry table pointer */
 653	int			lfloglow;	/* low leaf logging index */
 654	int			lfloghigh;	/* high leaf logging index */
 655	int			lowstale;	/* index of prev stale leaf */
 656	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail pointer */
 657	int			needbytes;	/* leaf block bytes needed */
 658	int			needlog;	/* need to log data header */
 659	int			needscan;	/* need to rescan data free */
 660	__be16			*tagp;		/* end of data entry */
 661	xfs_trans_t		*tp;		/* transaction pointer */
 662	xfs_dir2_db_t		use_block;	/* data block number */
 663	struct xfs_dir2_data_free *bf;		/* bestfree table */
 664	struct xfs_dir2_leaf_entry *ents;
 665	struct xfs_dir3_icleaf_hdr leafhdr;
 666
 667	trace_xfs_dir2_leaf_addname(args);
 668
 669	dp = args->dp;
 670	tp = args->trans;
 671
 672	error = xfs_dir3_leaf_read(tp, dp, args->geo->leafblk, -1, &lbp);
 673	if (error)
 674		return error;
 675
 676	/*
 677	 * Look up the entry by hash value and name.
 678	 * We know it's not there, our caller has already done a lookup.
 679	 * So the index is of the entry to insert in front of.
 680	 * But if there are dup hash values the index is of the first of those.
 681	 */
 682	index = xfs_dir2_leaf_search_hash(args, lbp);
 683	leaf = lbp->b_addr;
 684	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
 685	ents = dp->d_ops->leaf_ents_p(leaf);
 686	dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
 687	bestsp = xfs_dir2_leaf_bests_p(ltp);
 688	length = dp->d_ops->data_entsize(args->namelen);
 689
 690	/*
 691	 * See if there are any entries with the same hash value
 692	 * and space in their block for the new entry.
 693	 * This is good because it puts multiple same-hash value entries
 694	 * in a data block, improving the lookup of those entries.
 695	 */
 696	for (use_block = -1, lep = &ents[index];
 697	     index < leafhdr.count && be32_to_cpu(lep->hashval) == args->hashval;
 698	     index++, lep++) {
 699		if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
 700			continue;
 701		i = xfs_dir2_dataptr_to_db(args->geo, be32_to_cpu(lep->address));
 702		ASSERT(i < be32_to_cpu(ltp->bestcount));
 703		ASSERT(bestsp[i] != cpu_to_be16(NULLDATAOFF));
 704		if (be16_to_cpu(bestsp[i]) >= length) {
 705			use_block = i;
 706			break;
 707		}
 708	}
 709	/*
 710	 * Didn't find a block yet, linear search all the data blocks.
 711	 */
 712	if (use_block == -1) {
 713		for (i = 0; i < be32_to_cpu(ltp->bestcount); i++) {
 714			/*
 715			 * Remember a block we see that's missing.
 716			 */
 717			if (bestsp[i] == cpu_to_be16(NULLDATAOFF) &&
 718			    use_block == -1)
 719				use_block = i;
 720			else if (be16_to_cpu(bestsp[i]) >= length) {
 721				use_block = i;
 722				break;
 723			}
 724		}
 725	}
 726	/*
 727	 * How many bytes do we need in the leaf block?
 728	 */
 729	needbytes = 0;
 730	if (!leafhdr.stale)
 731		needbytes += sizeof(xfs_dir2_leaf_entry_t);
 732	if (use_block == -1)
 733		needbytes += sizeof(xfs_dir2_data_off_t);
 734
 735	/*
 736	 * Now kill use_block if it refers to a missing block, so we
 737	 * can use it as an indication of allocation needed.
 738	 */
 739	if (use_block != -1 && bestsp[use_block] == cpu_to_be16(NULLDATAOFF))
 740		use_block = -1;
 741	/*
 742	 * If we don't have enough free bytes but we can make enough
 743	 * by compacting out stale entries, we'll do that.
 744	 */
 745	if ((char *)bestsp - (char *)&ents[leafhdr.count] < needbytes &&
 746	    leafhdr.stale > 1)
 747		compact = 1;
 748
 749	/*
 750	 * Otherwise if we don't have enough free bytes we need to
 751	 * convert to node form.
 752	 */
 753	else if ((char *)bestsp - (char *)&ents[leafhdr.count] < needbytes) {
 754		/*
 755		 * Just checking or no space reservation, give up.
 756		 */
 757		if ((args->op_flags & XFS_DA_OP_JUSTCHECK) ||
 758							args->total == 0) {
 759			xfs_trans_brelse(tp, lbp);
 760			return -ENOSPC;
 761		}
 762		/*
 763		 * Convert to node form.
 764		 */
 765		error = xfs_dir2_leaf_to_node(args, lbp);
 766		if (error)
 767			return error;
 768		/*
 769		 * Then add the new entry.
 770		 */
 771		return xfs_dir2_node_addname(args);
 772	}
 773	/*
 774	 * Otherwise it will fit without compaction.
 775	 */
 776	else
 777		compact = 0;
 778	/*
 779	 * If just checking, then it will fit unless we needed to allocate
 780	 * a new data block.
 781	 */
 782	if (args->op_flags & XFS_DA_OP_JUSTCHECK) {
 783		xfs_trans_brelse(tp, lbp);
 784		return use_block == -1 ? -ENOSPC : 0;
 785	}
 786	/*
 787	 * If no allocations are allowed, return now before we've
 788	 * changed anything.
 789	 */
 790	if (args->total == 0 && use_block == -1) {
 791		xfs_trans_brelse(tp, lbp);
 792		return -ENOSPC;
 793	}
 794	/*
 795	 * Need to compact the leaf entries, removing stale ones.
 796	 * Leave one stale entry behind - the one closest to our
 797	 * insertion index - and we'll shift that one to our insertion
 798	 * point later.
 799	 */
 800	if (compact) {
 801		xfs_dir3_leaf_compact_x1(&leafhdr, ents, &index, &lowstale,
 802			&highstale, &lfloglow, &lfloghigh);
 803	}
 804	/*
 805	 * There are stale entries, so we'll need log-low and log-high
 806	 * impossibly bad values later.
 807	 */
 808	else if (leafhdr.stale) {
 809		lfloglow = leafhdr.count;
 810		lfloghigh = -1;
 811	}
 812	/*
 813	 * If there was no data block space found, we need to allocate
 814	 * a new one.
 815	 */
 816	if (use_block == -1) {
 817		/*
 818		 * Add the new data block.
 819		 */
 820		if ((error = xfs_dir2_grow_inode(args, XFS_DIR2_DATA_SPACE,
 821				&use_block))) {
 822			xfs_trans_brelse(tp, lbp);
 823			return error;
 824		}
 825		/*
 826		 * Initialize the block.
 827		 */
 828		if ((error = xfs_dir3_data_init(args, use_block, &dbp))) {
 829			xfs_trans_brelse(tp, lbp);
 830			return error;
 831		}
 832		/*
 833		 * If we're adding a new data block on the end we need to
 834		 * extend the bests table.  Copy it up one entry.
 835		 */
 836		if (use_block >= be32_to_cpu(ltp->bestcount)) {
 837			bestsp--;
 838			memmove(&bestsp[0], &bestsp[1],
 839				be32_to_cpu(ltp->bestcount) * sizeof(bestsp[0]));
 840			be32_add_cpu(&ltp->bestcount, 1);
 841			xfs_dir3_leaf_log_tail(args, lbp);
 842			xfs_dir3_leaf_log_bests(args, lbp, 0,
 843						be32_to_cpu(ltp->bestcount) - 1);
 844		}
 845		/*
 846		 * If we're filling in a previously empty block just log it.
 847		 */
 848		else
 849			xfs_dir3_leaf_log_bests(args, lbp, use_block, use_block);
 850		hdr = dbp->b_addr;
 851		bf = dp->d_ops->data_bestfree_p(hdr);
 852		bestsp[use_block] = bf[0].length;
 853		grown = 1;
 854	} else {
 855		/*
 856		 * Already had space in some data block.
 857		 * Just read that one in.
 858		 */
 859		error = xfs_dir3_data_read(tp, dp,
 860				   xfs_dir2_db_to_da(args->geo, use_block),
 861				   -1, &dbp);
 862		if (error) {
 863			xfs_trans_brelse(tp, lbp);
 864			return error;
 865		}
 866		hdr = dbp->b_addr;
 867		bf = dp->d_ops->data_bestfree_p(hdr);
 868		grown = 0;
 869	}
 870	/*
 871	 * Point to the biggest freespace in our data block.
 872	 */
 873	dup = (xfs_dir2_data_unused_t *)
 874	      ((char *)hdr + be16_to_cpu(bf[0].offset));
 875	ASSERT(be16_to_cpu(dup->length) >= length);
 876	needscan = needlog = 0;
 877	/*
 878	 * Mark the initial part of our freespace in use for the new entry.
 879	 */
 880	error = xfs_dir2_data_use_free(args, dbp, dup,
 881			(xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr),
 882			length, &needlog, &needscan);
 883	if (error) {
 884		xfs_trans_brelse(tp, lbp);
 885		return error;
 886	}
 887	/*
 888	 * Initialize our new entry (at last).
 889	 */
 890	dep = (xfs_dir2_data_entry_t *)dup;
 891	dep->inumber = cpu_to_be64(args->inumber);
 892	dep->namelen = args->namelen;
 893	memcpy(dep->name, args->name, dep->namelen);
 894	dp->d_ops->data_put_ftype(dep, args->filetype);
 895	tagp = dp->d_ops->data_entry_tag_p(dep);
 896	*tagp = cpu_to_be16((char *)dep - (char *)hdr);
 897	/*
 898	 * Need to scan fix up the bestfree table.
 899	 */
 900	if (needscan)
 901		xfs_dir2_data_freescan(dp, hdr, &needlog);
 902	/*
 903	 * Need to log the data block's header.
 904	 */
 905	if (needlog)
 906		xfs_dir2_data_log_header(args, dbp);
 907	xfs_dir2_data_log_entry(args, dbp, dep);
 908	/*
 909	 * If the bests table needs to be changed, do it.
 910	 * Log the change unless we've already done that.
 911	 */
 912	if (be16_to_cpu(bestsp[use_block]) != be16_to_cpu(bf[0].length)) {
 913		bestsp[use_block] = bf[0].length;
 914		if (!grown)
 915			xfs_dir3_leaf_log_bests(args, lbp, use_block, use_block);
 916	}
 917
 918	lep = xfs_dir3_leaf_find_entry(&leafhdr, ents, index, compact, lowstale,
 919				       highstale, &lfloglow, &lfloghigh);
 920
 921	/*
 922	 * Fill in the new leaf entry.
 923	 */
 924	lep->hashval = cpu_to_be32(args->hashval);
 925	lep->address = cpu_to_be32(
 926				xfs_dir2_db_off_to_dataptr(args->geo, use_block,
 927				be16_to_cpu(*tagp)));
 928	/*
 929	 * Log the leaf fields and give up the buffers.
 930	 */
 931	dp->d_ops->leaf_hdr_to_disk(leaf, &leafhdr);
 932	xfs_dir3_leaf_log_header(args, lbp);
 933	xfs_dir3_leaf_log_ents(args, lbp, lfloglow, lfloghigh);
 934	xfs_dir3_leaf_check(dp, lbp);
 935	xfs_dir3_data_check(dp, dbp);
 936	return 0;
 937}
 938
 939/*
 940 * Compact out any stale entries in the leaf.
 941 * Log the header and changed leaf entries, if any.
 942 */
 943void
 944xfs_dir3_leaf_compact(
 945	xfs_da_args_t	*args,		/* operation arguments */
 946	struct xfs_dir3_icleaf_hdr *leafhdr,
 947	struct xfs_buf	*bp)		/* leaf buffer */
 948{
 949	int		from;		/* source leaf index */
 950	xfs_dir2_leaf_t	*leaf;		/* leaf structure */
 951	int		loglow;		/* first leaf entry to log */
 952	int		to;		/* target leaf index */
 953	struct xfs_dir2_leaf_entry *ents;
 954	struct xfs_inode *dp = args->dp;
 955
 956	leaf = bp->b_addr;
 957	if (!leafhdr->stale)
 958		return;
 959
 960	/*
 961	 * Compress out the stale entries in place.
 962	 */
 963	ents = dp->d_ops->leaf_ents_p(leaf);
 964	for (from = to = 0, loglow = -1; from < leafhdr->count; from++) {
 965		if (ents[from].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 966			continue;
 967		/*
 968		 * Only actually copy the entries that are different.
 969		 */
 970		if (from > to) {
 971			if (loglow == -1)
 972				loglow = to;
 973			ents[to] = ents[from];
 974		}
 975		to++;
 976	}
 977	/*
 978	 * Update and log the header, log the leaf entries.
 979	 */
 980	ASSERT(leafhdr->stale == from - to);
 981	leafhdr->count -= leafhdr->stale;
 982	leafhdr->stale = 0;
 983
 984	dp->d_ops->leaf_hdr_to_disk(leaf, leafhdr);
 985	xfs_dir3_leaf_log_header(args, bp);
 986	if (loglow != -1)
 987		xfs_dir3_leaf_log_ents(args, bp, loglow, to - 1);
 988}
 989
 990/*
 991 * Compact the leaf entries, removing stale ones.
 992 * Leave one stale entry behind - the one closest to our
 993 * insertion index - and the caller will shift that one to our insertion
 994 * point later.
 995 * Return new insertion index, where the remaining stale entry is,
 996 * and leaf logging indices.
 997 */
 998void
 999xfs_dir3_leaf_compact_x1(
1000	struct xfs_dir3_icleaf_hdr *leafhdr,
1001	struct xfs_dir2_leaf_entry *ents,
1002	int		*indexp,	/* insertion index */
1003	int		*lowstalep,	/* out: stale entry before us */
1004	int		*highstalep,	/* out: stale entry after us */
1005	int		*lowlogp,	/* out: low log index */
1006	int		*highlogp)	/* out: high log index */
1007{
1008	int		from;		/* source copy index */
1009	int		highstale;	/* stale entry at/after index */
1010	int		index;		/* insertion index */
1011	int		keepstale;	/* source index of kept stale */
1012	int		lowstale;	/* stale entry before index */
1013	int		newindex=0;	/* new insertion index */
1014	int		to;		/* destination copy index */
1015
1016	ASSERT(leafhdr->stale > 1);
1017	index = *indexp;
1018
1019	xfs_dir3_leaf_find_stale(leafhdr, ents, index, &lowstale, &highstale);
1020
1021	/*
1022	 * Pick the better of lowstale and highstale.
1023	 */
1024	if (lowstale >= 0 &&
1025	    (highstale == leafhdr->count ||
1026	     index - lowstale <= highstale - index))
1027		keepstale = lowstale;
1028	else
1029		keepstale = highstale;
1030	/*
1031	 * Copy the entries in place, removing all the stale entries
1032	 * except keepstale.
1033	 */
1034	for (from = to = 0; from < leafhdr->count; from++) {
1035		/*
1036		 * Notice the new value of index.
1037		 */
1038		if (index == from)
1039			newindex = to;
1040		if (from != keepstale &&
1041		    ents[from].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR)) {
1042			if (from == to)
1043				*lowlogp = to;
1044			continue;
1045		}
1046		/*
1047		 * Record the new keepstale value for the insertion.
1048		 */
1049		if (from == keepstale)
1050			lowstale = highstale = to;
1051		/*
1052		 * Copy only the entries that have moved.
1053		 */
1054		if (from > to)
1055			ents[to] = ents[from];
1056		to++;
1057	}
1058	ASSERT(from > to);
1059	/*
1060	 * If the insertion point was past the last entry,
1061	 * set the new insertion point accordingly.
1062	 */
1063	if (index == from)
1064		newindex = to;
1065	*indexp = newindex;
1066	/*
1067	 * Adjust the leaf header values.
1068	 */
1069	leafhdr->count -= from - to;
1070	leafhdr->stale = 1;
1071	/*
1072	 * Remember the low/high stale value only in the "right"
1073	 * direction.
1074	 */
1075	if (lowstale >= newindex)
1076		lowstale = -1;
1077	else
1078		highstale = leafhdr->count;
1079	*highlogp = leafhdr->count - 1;
1080	*lowstalep = lowstale;
1081	*highstalep = highstale;
1082}
1083
1084/*
1085 * Log the bests entries indicated from a leaf1 block.
1086 */
1087static void
1088xfs_dir3_leaf_log_bests(
1089	struct xfs_da_args	*args,
1090	struct xfs_buf		*bp,		/* leaf buffer */
1091	int			first,		/* first entry to log */
1092	int			last)		/* last entry to log */
1093{
1094	__be16			*firstb;	/* pointer to first entry */
1095	__be16			*lastb;		/* pointer to last entry */
1096	struct xfs_dir2_leaf	*leaf = bp->b_addr;
1097	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
1098
1099	ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC) ||
1100	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC));
1101
1102	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
1103	firstb = xfs_dir2_leaf_bests_p(ltp) + first;
1104	lastb = xfs_dir2_leaf_bests_p(ltp) + last;
1105	xfs_trans_log_buf(args->trans, bp,
1106		(uint)((char *)firstb - (char *)leaf),
1107		(uint)((char *)lastb - (char *)leaf + sizeof(*lastb) - 1));
1108}
1109
1110/*
1111 * Log the leaf entries indicated from a leaf1 or leafn block.
1112 */
1113void
1114xfs_dir3_leaf_log_ents(
1115	struct xfs_da_args	*args,
1116	struct xfs_buf		*bp,
1117	int			first,
1118	int			last)
1119{
1120	xfs_dir2_leaf_entry_t	*firstlep;	/* pointer to first entry */
1121	xfs_dir2_leaf_entry_t	*lastlep;	/* pointer to last entry */
1122	struct xfs_dir2_leaf	*leaf = bp->b_addr;
1123	struct xfs_dir2_leaf_entry *ents;
1124
1125	ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC) ||
1126	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) ||
1127	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1128	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC));
1129
1130	ents = args->dp->d_ops->leaf_ents_p(leaf);
1131	firstlep = &ents[first];
1132	lastlep = &ents[last];
1133	xfs_trans_log_buf(args->trans, bp,
1134		(uint)((char *)firstlep - (char *)leaf),
1135		(uint)((char *)lastlep - (char *)leaf + sizeof(*lastlep) - 1));
1136}
1137
1138/*
1139 * Log the header of the leaf1 or leafn block.
1140 */
1141void
1142xfs_dir3_leaf_log_header(
1143	struct xfs_da_args	*args,
1144	struct xfs_buf		*bp)
1145{
1146	struct xfs_dir2_leaf	*leaf = bp->b_addr;
1147
1148	ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC) ||
1149	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) ||
1150	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1151	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC));
1152
1153	xfs_trans_log_buf(args->trans, bp,
1154			  (uint)((char *)&leaf->hdr - (char *)leaf),
1155			  args->dp->d_ops->leaf_hdr_size - 1);
1156}
1157
1158/*
1159 * Log the tail of the leaf1 block.
1160 */
1161STATIC void
1162xfs_dir3_leaf_log_tail(
1163	struct xfs_da_args	*args,
1164	struct xfs_buf		*bp)
1165{
1166	struct xfs_dir2_leaf	*leaf = bp->b_addr;
1167	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
1168
1169	ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC) ||
1170	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAF1_MAGIC) ||
1171	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1172	       leaf->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC));
1173
1174	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
1175	xfs_trans_log_buf(args->trans, bp, (uint)((char *)ltp - (char *)leaf),
1176		(uint)(args->geo->blksize - 1));
1177}
1178
1179/*
1180 * Look up the entry referred to by args in the leaf format directory.
1181 * Most of the work is done by the xfs_dir2_leaf_lookup_int routine which
1182 * is also used by the node-format code.
1183 */
1184int
1185xfs_dir2_leaf_lookup(
1186	xfs_da_args_t		*args)		/* operation arguments */
1187{
1188	struct xfs_buf		*dbp;		/* data block buffer */
1189	xfs_dir2_data_entry_t	*dep;		/* data block entry */
1190	xfs_inode_t		*dp;		/* incore directory inode */
1191	int			error;		/* error return code */
1192	int			index;		/* found entry index */
1193	struct xfs_buf		*lbp;		/* leaf buffer */
1194	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1195	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1196	xfs_trans_t		*tp;		/* transaction pointer */
1197	struct xfs_dir2_leaf_entry *ents;
1198
1199	trace_xfs_dir2_leaf_lookup(args);
1200
1201	/*
1202	 * Look up name in the leaf block, returning both buffers and index.
1203	 */
1204	if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1205		return error;
1206	}
1207	tp = args->trans;
1208	dp = args->dp;
1209	xfs_dir3_leaf_check(dp, lbp);
1210	leaf = lbp->b_addr;
1211	ents = dp->d_ops->leaf_ents_p(leaf);
1212	/*
1213	 * Get to the leaf entry and contained data entry address.
1214	 */
1215	lep = &ents[index];
1216
1217	/*
1218	 * Point to the data entry.
1219	 */
1220	dep = (xfs_dir2_data_entry_t *)
1221	      ((char *)dbp->b_addr +
1222	       xfs_dir2_dataptr_to_off(args->geo, be32_to_cpu(lep->address)));
1223	/*
1224	 * Return the found inode number & CI name if appropriate
1225	 */
1226	args->inumber = be64_to_cpu(dep->inumber);
1227	args->filetype = dp->d_ops->data_get_ftype(dep);
1228	error = xfs_dir_cilookup_result(args, dep->name, dep->namelen);
1229	xfs_trans_brelse(tp, dbp);
1230	xfs_trans_brelse(tp, lbp);
1231	return error;
1232}
1233
1234/*
1235 * Look up name/hash in the leaf block.
1236 * Fill in indexp with the found index, and dbpp with the data buffer.
1237 * If not found dbpp will be NULL, and ENOENT comes back.
1238 * lbpp will always be filled in with the leaf buffer unless there's an error.
1239 */
1240static int					/* error */
1241xfs_dir2_leaf_lookup_int(
1242	xfs_da_args_t		*args,		/* operation arguments */
1243	struct xfs_buf		**lbpp,		/* out: leaf buffer */
1244	int			*indexp,	/* out: index in leaf block */
1245	struct xfs_buf		**dbpp)		/* out: data buffer */
1246{
1247	xfs_dir2_db_t		curdb = -1;	/* current data block number */
1248	struct xfs_buf		*dbp = NULL;	/* data buffer */
1249	xfs_dir2_data_entry_t	*dep;		/* data entry */
1250	xfs_inode_t		*dp;		/* incore directory inode */
1251	int			error;		/* error return code */
1252	int			index;		/* index in leaf block */
1253	struct xfs_buf		*lbp;		/* leaf buffer */
1254	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1255	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1256	xfs_mount_t		*mp;		/* filesystem mount point */
1257	xfs_dir2_db_t		newdb;		/* new data block number */
1258	xfs_trans_t		*tp;		/* transaction pointer */
1259	xfs_dir2_db_t		cidb = -1;	/* case match data block no. */
1260	enum xfs_dacmp		cmp;		/* name compare result */
1261	struct xfs_dir2_leaf_entry *ents;
1262	struct xfs_dir3_icleaf_hdr leafhdr;
1263
1264	dp = args->dp;
1265	tp = args->trans;
1266	mp = dp->i_mount;
1267
1268	error = xfs_dir3_leaf_read(tp, dp, args->geo->leafblk, -1, &lbp);
1269	if (error)
1270		return error;
1271
1272	*lbpp = lbp;
1273	leaf = lbp->b_addr;
1274	xfs_dir3_leaf_check(dp, lbp);
1275	ents = dp->d_ops->leaf_ents_p(leaf);
1276	dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
1277
1278	/*
1279	 * Look for the first leaf entry with our hash value.
1280	 */
1281	index = xfs_dir2_leaf_search_hash(args, lbp);
1282	/*
1283	 * Loop over all the entries with the right hash value
1284	 * looking to match the name.
1285	 */
1286	for (lep = &ents[index];
1287	     index < leafhdr.count && be32_to_cpu(lep->hashval) == args->hashval;
1288	     lep++, index++) {
1289		/*
1290		 * Skip over stale leaf entries.
1291		 */
1292		if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
1293			continue;
1294		/*
1295		 * Get the new data block number.
1296		 */
1297		newdb = xfs_dir2_dataptr_to_db(args->geo,
1298					       be32_to_cpu(lep->address));
1299		/*
1300		 * If it's not the same as the old data block number,
1301		 * need to pitch the old one and read the new one.
1302		 */
1303		if (newdb != curdb) {
1304			if (dbp)
1305				xfs_trans_brelse(tp, dbp);
1306			error = xfs_dir3_data_read(tp, dp,
1307					   xfs_dir2_db_to_da(args->geo, newdb),
1308					   -1, &dbp);
1309			if (error) {
1310				xfs_trans_brelse(tp, lbp);
1311				return error;
1312			}
1313			curdb = newdb;
1314		}
1315		/*
1316		 * Point to the data entry.
1317		 */
1318		dep = (xfs_dir2_data_entry_t *)((char *)dbp->b_addr +
1319			xfs_dir2_dataptr_to_off(args->geo,
1320						be32_to_cpu(lep->address)));
1321		/*
1322		 * Compare name and if it's an exact match, return the index
1323		 * and buffer. If it's the first case-insensitive match, store
1324		 * the index and buffer and continue looking for an exact match.
1325		 */
1326		cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
1327		if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
1328			args->cmpresult = cmp;
1329			*indexp = index;
1330			/* case exact match: return the current buffer. */
1331			if (cmp == XFS_CMP_EXACT) {
1332				*dbpp = dbp;
1333				return 0;
1334			}
1335			cidb = curdb;
1336		}
1337	}
1338	ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1339	/*
1340	 * Here, we can only be doing a lookup (not a rename or remove).
1341	 * If a case-insensitive match was found earlier, re-read the
1342	 * appropriate data block if required and return it.
1343	 */
1344	if (args->cmpresult == XFS_CMP_CASE) {
1345		ASSERT(cidb != -1);
1346		if (cidb != curdb) {
1347			xfs_trans_brelse(tp, dbp);
1348			error = xfs_dir3_data_read(tp, dp,
1349					   xfs_dir2_db_to_da(args->geo, cidb),
1350					   -1, &dbp);
1351			if (error) {
1352				xfs_trans_brelse(tp, lbp);
1353				return error;
1354			}
1355		}
1356		*dbpp = dbp;
1357		return 0;
1358	}
1359	/*
1360	 * No match found, return -ENOENT.
1361	 */
1362	ASSERT(cidb == -1);
1363	if (dbp)
1364		xfs_trans_brelse(tp, dbp);
1365	xfs_trans_brelse(tp, lbp);
1366	return -ENOENT;
1367}
1368
1369/*
1370 * Remove an entry from a leaf format directory.
1371 */
1372int						/* error */
1373xfs_dir2_leaf_removename(
1374	xfs_da_args_t		*args)		/* operation arguments */
1375{
1376	__be16			*bestsp;	/* leaf block best freespace */
1377	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
1378	xfs_dir2_db_t		db;		/* data block number */
1379	struct xfs_buf		*dbp;		/* data block buffer */
1380	xfs_dir2_data_entry_t	*dep;		/* data entry structure */
1381	xfs_inode_t		*dp;		/* incore directory inode */
1382	int			error;		/* error return code */
1383	xfs_dir2_db_t		i;		/* temporary data block # */
1384	int			index;		/* index into leaf entries */
1385	struct xfs_buf		*lbp;		/* leaf buffer */
1386	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1387	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1388	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
1389	int			needlog;	/* need to log data header */
1390	int			needscan;	/* need to rescan data frees */
1391	xfs_dir2_data_off_t	oldbest;	/* old value of best free */
1392	struct xfs_dir2_data_free *bf;		/* bestfree table */
1393	struct xfs_dir2_leaf_entry *ents;
1394	struct xfs_dir3_icleaf_hdr leafhdr;
1395
1396	trace_xfs_dir2_leaf_removename(args);
1397
1398	/*
1399	 * Lookup the leaf entry, get the leaf and data blocks read in.
1400	 */
1401	if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1402		return error;
1403	}
1404	dp = args->dp;
1405	leaf = lbp->b_addr;
1406	hdr = dbp->b_addr;
1407	xfs_dir3_data_check(dp, dbp);
1408	bf = dp->d_ops->data_bestfree_p(hdr);
1409	dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
1410	ents = dp->d_ops->leaf_ents_p(leaf);
1411	/*
1412	 * Point to the leaf entry, use that to point to the data entry.
1413	 */
1414	lep = &ents[index];
1415	db = xfs_dir2_dataptr_to_db(args->geo, be32_to_cpu(lep->address));
1416	dep = (xfs_dir2_data_entry_t *)((char *)hdr +
1417		xfs_dir2_dataptr_to_off(args->geo, be32_to_cpu(lep->address)));
1418	needscan = needlog = 0;
1419	oldbest = be16_to_cpu(bf[0].length);
1420	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
1421	bestsp = xfs_dir2_leaf_bests_p(ltp);
1422	if (be16_to_cpu(bestsp[db]) != oldbest)
1423		return -EFSCORRUPTED;
1424	/*
1425	 * Mark the former data entry unused.
1426	 */
1427	xfs_dir2_data_make_free(args, dbp,
1428		(xfs_dir2_data_aoff_t)((char *)dep - (char *)hdr),
1429		dp->d_ops->data_entsize(dep->namelen), &needlog, &needscan);
1430	/*
1431	 * We just mark the leaf entry stale by putting a null in it.
1432	 */
1433	leafhdr.stale++;
1434	dp->d_ops->leaf_hdr_to_disk(leaf, &leafhdr);
1435	xfs_dir3_leaf_log_header(args, lbp);
1436
1437	lep->address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
1438	xfs_dir3_leaf_log_ents(args, lbp, index, index);
1439
1440	/*
1441	 * Scan the freespace in the data block again if necessary,
1442	 * log the data block header if necessary.
1443	 */
1444	if (needscan)
1445		xfs_dir2_data_freescan(dp, hdr, &needlog);
1446	if (needlog)
1447		xfs_dir2_data_log_header(args, dbp);
1448	/*
1449	 * If the longest freespace in the data block has changed,
1450	 * put the new value in the bests table and log that.
1451	 */
1452	if (be16_to_cpu(bf[0].length) != oldbest) {
1453		bestsp[db] = bf[0].length;
1454		xfs_dir3_leaf_log_bests(args, lbp, db, db);
1455	}
1456	xfs_dir3_data_check(dp, dbp);
1457	/*
1458	 * If the data block is now empty then get rid of the data block.
1459	 */
1460	if (be16_to_cpu(bf[0].length) ==
1461			args->geo->blksize - dp->d_ops->data_entry_offset) {
1462		ASSERT(db != args->geo->datablk);
1463		if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
1464			/*
1465			 * Nope, can't get rid of it because it caused
1466			 * allocation of a bmap btree block to do so.
1467			 * Just go on, returning success, leaving the
1468			 * empty block in place.
1469			 */
1470			if (error == -ENOSPC && args->total == 0)
1471				error = 0;
1472			xfs_dir3_leaf_check(dp, lbp);
1473			return error;
1474		}
1475		dbp = NULL;
1476		/*
1477		 * If this is the last data block then compact the
1478		 * bests table by getting rid of entries.
1479		 */
1480		if (db == be32_to_cpu(ltp->bestcount) - 1) {
1481			/*
1482			 * Look for the last active entry (i).
1483			 */
1484			for (i = db - 1; i > 0; i--) {
1485				if (bestsp[i] != cpu_to_be16(NULLDATAOFF))
1486					break;
1487			}
1488			/*
1489			 * Copy the table down so inactive entries at the
1490			 * end are removed.
1491			 */
1492			memmove(&bestsp[db - i], bestsp,
1493				(be32_to_cpu(ltp->bestcount) - (db - i)) * sizeof(*bestsp));
1494			be32_add_cpu(&ltp->bestcount, -(db - i));
1495			xfs_dir3_leaf_log_tail(args, lbp);
1496			xfs_dir3_leaf_log_bests(args, lbp, 0,
1497						be32_to_cpu(ltp->bestcount) - 1);
1498		} else
1499			bestsp[db] = cpu_to_be16(NULLDATAOFF);
1500	}
1501	/*
1502	 * If the data block was not the first one, drop it.
1503	 */
1504	else if (db != args->geo->datablk)
1505		dbp = NULL;
1506
1507	xfs_dir3_leaf_check(dp, lbp);
1508	/*
1509	 * See if we can convert to block form.
1510	 */
1511	return xfs_dir2_leaf_to_block(args, lbp, dbp);
1512}
1513
1514/*
1515 * Replace the inode number in a leaf format directory entry.
1516 */
1517int						/* error */
1518xfs_dir2_leaf_replace(
1519	xfs_da_args_t		*args)		/* operation arguments */
1520{
1521	struct xfs_buf		*dbp;		/* data block buffer */
1522	xfs_dir2_data_entry_t	*dep;		/* data block entry */
1523	xfs_inode_t		*dp;		/* incore directory inode */
1524	int			error;		/* error return code */
1525	int			index;		/* index of leaf entry */
1526	struct xfs_buf		*lbp;		/* leaf buffer */
1527	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1528	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1529	xfs_trans_t		*tp;		/* transaction pointer */
1530	struct xfs_dir2_leaf_entry *ents;
1531
1532	trace_xfs_dir2_leaf_replace(args);
1533
1534	/*
1535	 * Look up the entry.
1536	 */
1537	if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1538		return error;
1539	}
1540	dp = args->dp;
1541	leaf = lbp->b_addr;
1542	ents = dp->d_ops->leaf_ents_p(leaf);
1543	/*
1544	 * Point to the leaf entry, get data address from it.
1545	 */
1546	lep = &ents[index];
1547	/*
1548	 * Point to the data entry.
1549	 */
1550	dep = (xfs_dir2_data_entry_t *)
1551	      ((char *)dbp->b_addr +
1552	       xfs_dir2_dataptr_to_off(args->geo, be32_to_cpu(lep->address)));
1553	ASSERT(args->inumber != be64_to_cpu(dep->inumber));
1554	/*
1555	 * Put the new inode number in, log it.
1556	 */
1557	dep->inumber = cpu_to_be64(args->inumber);
1558	dp->d_ops->data_put_ftype(dep, args->filetype);
1559	tp = args->trans;
1560	xfs_dir2_data_log_entry(args, dbp, dep);
1561	xfs_dir3_leaf_check(dp, lbp);
1562	xfs_trans_brelse(tp, lbp);
1563	return 0;
1564}
1565
1566/*
1567 * Return index in the leaf block (lbp) which is either the first
1568 * one with this hash value, or if there are none, the insert point
1569 * for that hash value.
1570 */
1571int						/* index value */
1572xfs_dir2_leaf_search_hash(
1573	xfs_da_args_t		*args,		/* operation arguments */
1574	struct xfs_buf		*lbp)		/* leaf buffer */
1575{
1576	xfs_dahash_t		hash=0;		/* hash from this entry */
1577	xfs_dahash_t		hashwant;	/* hash value looking for */
1578	int			high;		/* high leaf index */
1579	int			low;		/* low leaf index */
1580	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1581	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
1582	int			mid=0;		/* current leaf index */
1583	struct xfs_dir2_leaf_entry *ents;
1584	struct xfs_dir3_icleaf_hdr leafhdr;
1585
1586	leaf = lbp->b_addr;
1587	ents = args->dp->d_ops->leaf_ents_p(leaf);
1588	args->dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
1589
1590	/*
1591	 * Note, the table cannot be empty, so we have to go through the loop.
1592	 * Binary search the leaf entries looking for our hash value.
1593	 */
1594	for (lep = ents, low = 0, high = leafhdr.count - 1,
1595		hashwant = args->hashval;
1596	     low <= high; ) {
1597		mid = (low + high) >> 1;
1598		if ((hash = be32_to_cpu(lep[mid].hashval)) == hashwant)
1599			break;
1600		if (hash < hashwant)
1601			low = mid + 1;
1602		else
1603			high = mid - 1;
1604	}
1605	/*
1606	 * Found one, back up through all the equal hash values.
1607	 */
1608	if (hash == hashwant) {
1609		while (mid > 0 && be32_to_cpu(lep[mid - 1].hashval) == hashwant) {
1610			mid--;
1611		}
1612	}
1613	/*
1614	 * Need to point to an entry higher than ours.
1615	 */
1616	else if (hash < hashwant)
1617		mid++;
1618	return mid;
1619}
1620
1621/*
1622 * Trim off a trailing data block.  We know it's empty since the leaf
1623 * freespace table says so.
1624 */
1625int						/* error */
1626xfs_dir2_leaf_trim_data(
1627	xfs_da_args_t		*args,		/* operation arguments */
1628	struct xfs_buf		*lbp,		/* leaf buffer */
1629	xfs_dir2_db_t		db)		/* data block number */
1630{
1631	__be16			*bestsp;	/* leaf bests table */
1632	struct xfs_buf		*dbp;		/* data block buffer */
1633	xfs_inode_t		*dp;		/* incore directory inode */
1634	int			error;		/* error return value */
1635	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1636	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
1637	xfs_trans_t		*tp;		/* transaction pointer */
1638
1639	dp = args->dp;
1640	tp = args->trans;
1641	/*
1642	 * Read the offending data block.  We need its buffer.
1643	 */
1644	error = xfs_dir3_data_read(tp, dp, xfs_dir2_db_to_da(args->geo, db),
1645				   -1, &dbp);
1646	if (error)
1647		return error;
1648
1649	leaf = lbp->b_addr;
1650	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
1651
1652#ifdef DEBUG
1653{
1654	struct xfs_dir2_data_hdr *hdr = dbp->b_addr;
1655	struct xfs_dir2_data_free *bf = dp->d_ops->data_bestfree_p(hdr);
1656
1657	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
1658	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC));
1659	ASSERT(be16_to_cpu(bf[0].length) ==
1660	       args->geo->blksize - dp->d_ops->data_entry_offset);
1661	ASSERT(db == be32_to_cpu(ltp->bestcount) - 1);
1662}
1663#endif
1664
1665	/*
1666	 * Get rid of the data block.
1667	 */
1668	if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
1669		ASSERT(error != -ENOSPC);
1670		xfs_trans_brelse(tp, dbp);
1671		return error;
1672	}
1673	/*
1674	 * Eliminate the last bests entry from the table.
1675	 */
1676	bestsp = xfs_dir2_leaf_bests_p(ltp);
1677	be32_add_cpu(&ltp->bestcount, -1);
1678	memmove(&bestsp[1], &bestsp[0], be32_to_cpu(ltp->bestcount) * sizeof(*bestsp));
1679	xfs_dir3_leaf_log_tail(args, lbp);
1680	xfs_dir3_leaf_log_bests(args, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1681	return 0;
1682}
1683
1684static inline size_t
1685xfs_dir3_leaf_size(
1686	struct xfs_dir3_icleaf_hdr	*hdr,
1687	int				counts)
1688{
1689	int	entries;
1690	int	hdrsize;
1691
1692	entries = hdr->count - hdr->stale;
1693	if (hdr->magic == XFS_DIR2_LEAF1_MAGIC ||
1694	    hdr->magic == XFS_DIR2_LEAFN_MAGIC)
1695		hdrsize = sizeof(struct xfs_dir2_leaf_hdr);
1696	else
1697		hdrsize = sizeof(struct xfs_dir3_leaf_hdr);
1698
1699	return hdrsize + entries * sizeof(xfs_dir2_leaf_entry_t)
1700	               + counts * sizeof(xfs_dir2_data_off_t)
1701		       + sizeof(xfs_dir2_leaf_tail_t);
1702}
1703
1704/*
1705 * Convert node form directory to leaf form directory.
1706 * The root of the node form dir needs to already be a LEAFN block.
1707 * Just return if we can't do anything.
1708 */
1709int						/* error */
1710xfs_dir2_node_to_leaf(
1711	xfs_da_state_t		*state)		/* directory operation state */
1712{
1713	xfs_da_args_t		*args;		/* operation arguments */
1714	xfs_inode_t		*dp;		/* incore directory inode */
1715	int			error;		/* error return code */
1716	struct xfs_buf		*fbp;		/* buffer for freespace block */
1717	xfs_fileoff_t		fo;		/* freespace file offset */
1718	xfs_dir2_free_t		*free;		/* freespace structure */
1719	struct xfs_buf		*lbp;		/* buffer for leaf block */
1720	xfs_dir2_leaf_tail_t	*ltp;		/* tail of leaf structure */
1721	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
1722	xfs_mount_t		*mp;		/* filesystem mount point */
1723	int			rval;		/* successful free trim? */
1724	xfs_trans_t		*tp;		/* transaction pointer */
1725	struct xfs_dir3_icleaf_hdr leafhdr;
1726	struct xfs_dir3_icfree_hdr freehdr;
1727
1728	/*
1729	 * There's more than a leaf level in the btree, so there must
1730	 * be multiple leafn blocks.  Give up.
1731	 */
1732	if (state->path.active > 1)
1733		return 0;
1734	args = state->args;
1735
1736	trace_xfs_dir2_node_to_leaf(args);
1737
1738	mp = state->mp;
1739	dp = args->dp;
1740	tp = args->trans;
1741	/*
1742	 * Get the last offset in the file.
1743	 */
1744	if ((error = xfs_bmap_last_offset(dp, &fo, XFS_DATA_FORK))) {
1745		return error;
1746	}
1747	fo -= args->geo->fsbcount;
1748	/*
1749	 * If there are freespace blocks other than the first one,
1750	 * take this opportunity to remove trailing empty freespace blocks
1751	 * that may have been left behind during no-space-reservation
1752	 * operations.
1753	 */
1754	while (fo > args->geo->freeblk) {
1755		if ((error = xfs_dir2_node_trim_free(args, fo, &rval))) {
1756			return error;
1757		}
1758		if (rval)
1759			fo -= args->geo->fsbcount;
1760		else
1761			return 0;
1762	}
1763	/*
1764	 * Now find the block just before the freespace block.
1765	 */
1766	if ((error = xfs_bmap_last_before(tp, dp, &fo, XFS_DATA_FORK))) {
1767		return error;
1768	}
1769	/*
1770	 * If it's not the single leaf block, give up.
1771	 */
1772	if (XFS_FSB_TO_B(mp, fo) > XFS_DIR2_LEAF_OFFSET + args->geo->blksize)
1773		return 0;
1774	lbp = state->path.blk[0].bp;
1775	leaf = lbp->b_addr;
1776	dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
1777
1778	ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
1779	       leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
1780
1781	/*
1782	 * Read the freespace block.
1783	 */
1784	error = xfs_dir2_free_read(tp, dp,  args->geo->freeblk, &fbp);
1785	if (error)
1786		return error;
1787	free = fbp->b_addr;
1788	dp->d_ops->free_hdr_from_disk(&freehdr, free);
1789
1790	ASSERT(!freehdr.firstdb);
1791
1792	/*
1793	 * Now see if the leafn and free data will fit in a leaf1.
1794	 * If not, release the buffer and give up.
1795	 */
1796	if (xfs_dir3_leaf_size(&leafhdr, freehdr.nvalid) > args->geo->blksize) {
1797		xfs_trans_brelse(tp, fbp);
1798		return 0;
1799	}
1800
1801	/*
1802	 * If the leaf has any stale entries in it, compress them out.
1803	 */
1804	if (leafhdr.stale)
1805		xfs_dir3_leaf_compact(args, &leafhdr, lbp);
1806
1807	lbp->b_ops = &xfs_dir3_leaf1_buf_ops;
1808	xfs_trans_buf_set_type(tp, lbp, XFS_BLFT_DIR_LEAF1_BUF);
1809	leafhdr.magic = (leafhdr.magic == XFS_DIR2_LEAFN_MAGIC)
1810					? XFS_DIR2_LEAF1_MAGIC
1811					: XFS_DIR3_LEAF1_MAGIC;
1812
1813	/*
1814	 * Set up the leaf tail from the freespace block.
1815	 */
1816	ltp = xfs_dir2_leaf_tail_p(args->geo, leaf);
1817	ltp->bestcount = cpu_to_be32(freehdr.nvalid);
1818
1819	/*
1820	 * Set up the leaf bests table.
1821	 */
1822	memcpy(xfs_dir2_leaf_bests_p(ltp), dp->d_ops->free_bests_p(free),
1823		freehdr.nvalid * sizeof(xfs_dir2_data_off_t));
1824
1825	dp->d_ops->leaf_hdr_to_disk(leaf, &leafhdr);
1826	xfs_dir3_leaf_log_header(args, lbp);
1827	xfs_dir3_leaf_log_bests(args, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1828	xfs_dir3_leaf_log_tail(args, lbp);
1829	xfs_dir3_leaf_check(dp, lbp);
1830
1831	/*
1832	 * Get rid of the freespace block.
1833	 */
1834	error = xfs_dir2_shrink_inode(args,
1835			xfs_dir2_byte_to_db(args->geo, XFS_DIR2_FREE_OFFSET),
1836			fbp);
1837	if (error) {
1838		/*
1839		 * This can't fail here because it can only happen when
1840		 * punching out the middle of an extent, and this is an
1841		 * isolated block.
1842		 */
1843		ASSERT(error != -ENOSPC);
1844		return error;
1845	}
1846	fbp = NULL;
1847	/*
1848	 * Now see if we can convert the single-leaf directory
1849	 * down to a block form directory.
1850	 * This routine always kills the dabuf for the leaf, so
1851	 * eliminate it from the path.
1852	 */
1853	error = xfs_dir2_leaf_to_block(args, lbp, NULL);
1854	state->path.blk[0].bp = NULL;
1855	return error;
1856}