Linux Audio

Check our new training course

Loading...
v4.17
 
   1/*
   2 * Copyright (c) 2000-2002,2005 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_dir2.h"
  29#include "xfs_dir2_priv.h"
  30#include "xfs_error.h"
  31#include "xfs_trans.h"
  32#include "xfs_buf_item.h"
  33#include "xfs_cksum.h"
  34#include "xfs_log.h"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  35
  36/*
  37 * Check the consistency of the data block.
  38 * The input can also be a block-format directory.
  39 * Return NULL if the buffer is good, otherwise the address of the error.
  40 */
  41xfs_failaddr_t
  42__xfs_dir3_data_check(
  43	struct xfs_inode	*dp,		/* incore inode pointer */
  44	struct xfs_buf		*bp)		/* data block's buffer */
  45{
  46	xfs_dir2_dataptr_t	addr;		/* addr for leaf lookup */
  47	xfs_dir2_data_free_t	*bf;		/* bestfree table */
  48	xfs_dir2_block_tail_t	*btp=NULL;	/* block tail */
  49	int			count;		/* count of entries found */
  50	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
  51	xfs_dir2_data_entry_t	*dep;		/* data entry */
  52	xfs_dir2_data_free_t	*dfp;		/* bestfree entry */
  53	xfs_dir2_data_unused_t	*dup;		/* unused entry */
  54	char			*endp;		/* end of useful data */
  55	int			freeseen;	/* mask of bestfrees seen */
  56	xfs_dahash_t		hash;		/* hash of current name */
  57	int			i;		/* leaf index */
  58	int			lastfree;	/* last entry was unused */
  59	xfs_dir2_leaf_entry_t	*lep=NULL;	/* block leaf entries */
  60	xfs_mount_t		*mp;		/* filesystem mount point */
  61	char			*p;		/* current data position */
  62	int			stale;		/* count of stale leaves */
  63	struct xfs_name		name;
  64	const struct xfs_dir_ops *ops;
  65	struct xfs_da_geometry	*geo;
  66
  67	mp = bp->b_target->bt_mount;
  68	geo = mp->m_dir_geo;
  69
  70	/*
  71	 * We can be passed a null dp here from a verifier, so we need to go the
  72	 * hard way to get them.
  73	 */
  74	ops = xfs_dir_get_ops(mp, dp);
  75
  76	/*
  77	 * If this isn't a directory, or we don't get handed the dir ops,
  78	 * something is seriously wrong.  Bail out.
  79	 */
  80	if ((dp && !S_ISDIR(VFS_I(dp)->i_mode)) ||
  81	    ops != xfs_dir_get_ops(mp, NULL))
  82		return __this_address;
  83
  84	hdr = bp->b_addr;
  85	p = (char *)ops->data_entry_p(hdr);
  86
  87	switch (hdr->magic) {
  88	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
  89	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
  90		btp = xfs_dir2_block_tail_p(geo, hdr);
  91		lep = xfs_dir2_block_leaf_p(btp);
  92
  93		/*
  94		 * The number of leaf entries is limited by the size of the
  95		 * block and the amount of space used by the data entries.
  96		 * We don't know how much space is used by the data entries yet,
  97		 * so just ensure that the count falls somewhere inside the
  98		 * block right now.
  99		 */
 100		if (be32_to_cpu(btp->count) >=
 101		    ((char *)btp - p) / sizeof(struct xfs_dir2_leaf_entry))
 102			return __this_address;
 103		break;
 104	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
 105	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
 106		break;
 107	default:
 108		return __this_address;
 109	}
 110	endp = xfs_dir3_data_endp(geo, hdr);
 111	if (!endp)
 112		return __this_address;
 113
 114	/*
 115	 * Account for zero bestfree entries.
 116	 */
 117	bf = ops->data_bestfree_p(hdr);
 118	count = lastfree = freeseen = 0;
 119	if (!bf[0].length) {
 120		if (bf[0].offset)
 121			return __this_address;
 122		freeseen |= 1 << 0;
 123	}
 124	if (!bf[1].length) {
 125		if (bf[1].offset)
 126			return __this_address;
 127		freeseen |= 1 << 1;
 128	}
 129	if (!bf[2].length) {
 130		if (bf[2].offset)
 131			return __this_address;
 132		freeseen |= 1 << 2;
 133	}
 134
 135	if (be16_to_cpu(bf[0].length) < be16_to_cpu(bf[1].length))
 136		return __this_address;
 137	if (be16_to_cpu(bf[1].length) < be16_to_cpu(bf[2].length))
 138		return __this_address;
 139	/*
 140	 * Loop over the data/unused entries.
 141	 */
 142	while (p < endp) {
 143		dup = (xfs_dir2_data_unused_t *)p;
 
 
 144		/*
 145		 * If it's unused, look for the space in the bestfree table.
 146		 * If we find it, account for that, else make sure it
 147		 * doesn't need to be there.
 148		 */
 149		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 
 
 150			if (lastfree != 0)
 151				return __this_address;
 152			if (endp < p + be16_to_cpu(dup->length))
 153				return __this_address;
 154			if (be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) !=
 155			    (char *)dup - (char *)hdr)
 156				return __this_address;
 157			dfp = xfs_dir2_data_freefind(hdr, bf, dup);
 
 
 158			if (dfp) {
 159				i = (int)(dfp - bf);
 160				if ((freeseen & (1 << i)) != 0)
 161					return __this_address;
 162				freeseen |= 1 << i;
 163			} else {
 164				if (be16_to_cpu(dup->length) >
 165				    be16_to_cpu(bf[2].length))
 166					return __this_address;
 167			}
 168			p += be16_to_cpu(dup->length);
 169			lastfree = 1;
 170			continue;
 171		}
 172		/*
 173		 * It's a real entry.  Validate the fields.
 174		 * If this is a block directory then make sure it's
 175		 * in the leaf section of the block.
 176		 * The linear search is crude but this is DEBUG code.
 177		 */
 178		dep = (xfs_dir2_data_entry_t *)p;
 179		if (dep->namelen == 0)
 180			return __this_address;
 181		if (xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)))
 182			return __this_address;
 183		if (endp < p + ops->data_entsize(dep->namelen))
 184			return __this_address;
 185		if (be16_to_cpu(*ops->data_entry_tag_p(dep)) !=
 186		    (char *)dep - (char *)hdr)
 187			return __this_address;
 188		if (ops->data_get_ftype(dep) >= XFS_DIR3_FT_MAX)
 189			return __this_address;
 190		count++;
 191		lastfree = 0;
 192		if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 193		    hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
 194			addr = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
 195						(xfs_dir2_data_aoff_t)
 196						((char *)dep - (char *)hdr));
 197			name.name = dep->name;
 198			name.len = dep->namelen;
 199			hash = mp->m_dirnameops->hashname(&name);
 200			for (i = 0; i < be32_to_cpu(btp->count); i++) {
 201				if (be32_to_cpu(lep[i].address) == addr &&
 202				    be32_to_cpu(lep[i].hashval) == hash)
 203					break;
 204			}
 205			if (i >= be32_to_cpu(btp->count))
 206				return __this_address;
 207		}
 208		p += ops->data_entsize(dep->namelen);
 209	}
 210	/*
 211	 * Need to have seen all the entries and all the bestfree slots.
 212	 */
 213	if (freeseen != 7)
 214		return __this_address;
 215	if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 216	    hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
 217		for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
 218			if (lep[i].address ==
 219			    cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 220				stale++;
 221			if (i > 0 && be32_to_cpu(lep[i].hashval) <
 222				     be32_to_cpu(lep[i - 1].hashval))
 223				return __this_address;
 224		}
 225		if (count != be32_to_cpu(btp->count) - be32_to_cpu(btp->stale))
 226			return __this_address;
 227		if (stale != be32_to_cpu(btp->stale))
 228			return __this_address;
 229	}
 230	return NULL;
 231}
 232
 233#ifdef DEBUG
 234void
 235xfs_dir3_data_check(
 236	struct xfs_inode	*dp,
 237	struct xfs_buf		*bp)
 238{
 239	xfs_failaddr_t		fa;
 240
 241	fa = __xfs_dir3_data_check(dp, bp);
 242	if (!fa)
 243		return;
 244	xfs_corruption_error(__func__, XFS_ERRLEVEL_LOW, dp->i_mount,
 245			bp->b_addr, __FILE__, __LINE__, fa);
 
 246	ASSERT(0);
 247}
 248#endif
 249
 250static xfs_failaddr_t
 251xfs_dir3_data_verify(
 252	struct xfs_buf		*bp)
 253{
 254	struct xfs_mount	*mp = bp->b_target->bt_mount;
 255	struct xfs_dir3_blk_hdr	*hdr3 = bp->b_addr;
 256
 257	if (xfs_sb_version_hascrc(&mp->m_sb)) {
 258		if (hdr3->magic != cpu_to_be32(XFS_DIR3_DATA_MAGIC))
 259			return __this_address;
 
 260		if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_meta_uuid))
 261			return __this_address;
 262		if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
 263			return __this_address;
 264		if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->lsn)))
 265			return __this_address;
 266	} else {
 267		if (hdr3->magic != cpu_to_be32(XFS_DIR2_DATA_MAGIC))
 268			return __this_address;
 269	}
 270	return __xfs_dir3_data_check(NULL, bp);
 271}
 272
 273/*
 274 * Readahead of the first block of the directory when it is opened is completely
 275 * oblivious to the format of the directory. Hence we can either get a block
 276 * format buffer or a data format buffer on readahead.
 277 */
 278static void
 279xfs_dir3_data_reada_verify(
 280	struct xfs_buf		*bp)
 281{
 282	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
 283
 284	switch (hdr->magic) {
 285	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
 286	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
 287		bp->b_ops = &xfs_dir3_block_buf_ops;
 288		bp->b_ops->verify_read(bp);
 289		return;
 290	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
 291	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
 292		bp->b_ops = &xfs_dir3_data_buf_ops;
 293		bp->b_ops->verify_read(bp);
 294		return;
 295	default:
 296		xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
 297		break;
 298	}
 299}
 300
 301static void
 302xfs_dir3_data_read_verify(
 303	struct xfs_buf	*bp)
 304{
 305	struct xfs_mount	*mp = bp->b_target->bt_mount;
 306	xfs_failaddr_t		fa;
 307
 308	if (xfs_sb_version_hascrc(&mp->m_sb) &&
 309	    !xfs_buf_verify_cksum(bp, XFS_DIR3_DATA_CRC_OFF))
 310		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 311	else {
 312		fa = xfs_dir3_data_verify(bp);
 313		if (fa)
 314			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 315	}
 316}
 317
 318static void
 319xfs_dir3_data_write_verify(
 320	struct xfs_buf	*bp)
 321{
 322	struct xfs_mount	*mp = bp->b_target->bt_mount;
 323	struct xfs_buf_log_item	*bip = bp->b_log_item;
 324	struct xfs_dir3_blk_hdr	*hdr3 = bp->b_addr;
 325	xfs_failaddr_t		fa;
 326
 327	fa = xfs_dir3_data_verify(bp);
 328	if (fa) {
 329		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 330		return;
 331	}
 332
 333	if (!xfs_sb_version_hascrc(&mp->m_sb))
 334		return;
 335
 336	if (bip)
 337		hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
 338
 339	xfs_buf_update_cksum(bp, XFS_DIR3_DATA_CRC_OFF);
 340}
 341
 342const struct xfs_buf_ops xfs_dir3_data_buf_ops = {
 343	.name = "xfs_dir3_data",
 
 
 344	.verify_read = xfs_dir3_data_read_verify,
 345	.verify_write = xfs_dir3_data_write_verify,
 346	.verify_struct = xfs_dir3_data_verify,
 347};
 348
 349static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
 350	.name = "xfs_dir3_data_reada",
 
 
 351	.verify_read = xfs_dir3_data_reada_verify,
 352	.verify_write = xfs_dir3_data_write_verify,
 353};
 354
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 355
 356int
 357xfs_dir3_data_read(
 358	struct xfs_trans	*tp,
 359	struct xfs_inode	*dp,
 360	xfs_dablk_t		bno,
 361	xfs_daddr_t		mapped_bno,
 362	struct xfs_buf		**bpp)
 363{
 
 364	int			err;
 365
 366	err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
 367				XFS_DATA_FORK, &xfs_dir3_data_buf_ops);
 368	if (!err && tp && *bpp)
 369		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
 
 
 
 
 
 
 
 
 
 
 
 
 370	return err;
 371}
 372
 373int
 374xfs_dir3_data_readahead(
 375	struct xfs_inode	*dp,
 376	xfs_dablk_t		bno,
 377	xfs_daddr_t		mapped_bno)
 378{
 379	return xfs_da_reada_buf(dp, bno, mapped_bno,
 380				XFS_DATA_FORK, &xfs_dir3_data_reada_buf_ops);
 381}
 382
 383/*
 384 * Given a data block and an unused entry from that block,
 385 * return the bestfree entry if any that corresponds to it.
 386 */
 387xfs_dir2_data_free_t *
 388xfs_dir2_data_freefind(
 389	struct xfs_dir2_data_hdr *hdr,		/* data block header */
 390	struct xfs_dir2_data_free *bf,		/* bestfree table pointer */
 391	struct xfs_dir2_data_unused *dup)	/* unused space */
 
 392{
 393	xfs_dir2_data_free_t	*dfp;		/* bestfree entry */
 394	xfs_dir2_data_aoff_t	off;		/* offset value needed */
 395#ifdef DEBUG
 396	int			matched;	/* matched the value */
 397	int			seenzero;	/* saw a 0 bestfree entry */
 398#endif
 399
 
 400	off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
 401
 402#ifdef DEBUG
 403	/*
 404	 * Validate some consistency in the bestfree table.
 405	 * Check order, non-overlapping entries, and if we find the
 406	 * one we're looking for it has to be exact.
 407	 */
 408	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 409	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 410	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 411	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 412	for (dfp = &bf[0], seenzero = matched = 0;
 413	     dfp < &bf[XFS_DIR2_DATA_FD_COUNT];
 414	     dfp++) {
 415		if (!dfp->offset) {
 416			ASSERT(!dfp->length);
 417			seenzero = 1;
 
 418			continue;
 419		}
 420		ASSERT(seenzero == 0);
 
 421		if (be16_to_cpu(dfp->offset) == off) {
 422			matched = 1;
 423			ASSERT(dfp->length == dup->length);
 424		} else if (off < be16_to_cpu(dfp->offset))
 425			ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
 426		else
 427			ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
 428		ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
 429		if (dfp > &bf[0])
 430			ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
 
 
 
 
 
 
 
 
 
 431	}
 432#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 433	/*
 434	 * If this is smaller than the smallest bestfree entry,
 435	 * it can't be there since they're sorted.
 436	 */
 437	if (be16_to_cpu(dup->length) <
 438	    be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
 439		return NULL;
 440	/*
 441	 * Look at the three bestfree entries for our guy.
 442	 */
 443	for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
 444		if (!dfp->offset)
 445			return NULL;
 446		if (be16_to_cpu(dfp->offset) == off)
 447			return dfp;
 448	}
 449	/*
 450	 * Didn't find it.  This only happens if there are duplicate lengths.
 451	 */
 452	return NULL;
 453}
 454
 455/*
 456 * Insert an unused-space entry into the bestfree table.
 457 */
 458xfs_dir2_data_free_t *				/* entry inserted */
 459xfs_dir2_data_freeinsert(
 460	struct xfs_dir2_data_hdr *hdr,		/* data block pointer */
 461	struct xfs_dir2_data_free *dfp,		/* bestfree table pointer */
 462	struct xfs_dir2_data_unused *dup,	/* unused space */
 463	int			*loghead)	/* log the data header (out) */
 464{
 465	xfs_dir2_data_free_t	new;		/* new bestfree entry */
 466
 467	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 468	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 469	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 470	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 471
 472	new.length = dup->length;
 473	new.offset = cpu_to_be16((char *)dup - (char *)hdr);
 474
 475	/*
 476	 * Insert at position 0, 1, or 2; or not at all.
 477	 */
 478	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
 479		dfp[2] = dfp[1];
 480		dfp[1] = dfp[0];
 481		dfp[0] = new;
 482		*loghead = 1;
 483		return &dfp[0];
 484	}
 485	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
 486		dfp[2] = dfp[1];
 487		dfp[1] = new;
 488		*loghead = 1;
 489		return &dfp[1];
 490	}
 491	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
 492		dfp[2] = new;
 493		*loghead = 1;
 494		return &dfp[2];
 495	}
 496	return NULL;
 497}
 498
 499/*
 500 * Remove a bestfree entry from the table.
 501 */
 502STATIC void
 503xfs_dir2_data_freeremove(
 504	struct xfs_dir2_data_hdr *hdr,		/* data block header */
 505	struct xfs_dir2_data_free *bf,		/* bestfree table pointer */
 506	struct xfs_dir2_data_free *dfp,		/* bestfree entry pointer */
 507	int			*loghead)	/* out: log data header */
 508{
 509
 510	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 511	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 512	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 513	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 514
 515	/*
 516	 * It's the first entry, slide the next 2 up.
 517	 */
 518	if (dfp == &bf[0]) {
 519		bf[0] = bf[1];
 520		bf[1] = bf[2];
 521	}
 522	/*
 523	 * It's the second entry, slide the 3rd entry up.
 524	 */
 525	else if (dfp == &bf[1])
 526		bf[1] = bf[2];
 527	/*
 528	 * Must be the last entry.
 529	 */
 530	else
 531		ASSERT(dfp == &bf[2]);
 532	/*
 533	 * Clear the 3rd entry, must be zero now.
 534	 */
 535	bf[2].length = 0;
 536	bf[2].offset = 0;
 537	*loghead = 1;
 538}
 539
 540/*
 541 * Given a data block, reconstruct its bestfree map.
 542 */
 543void
 544xfs_dir2_data_freescan_int(
 545	struct xfs_da_geometry	*geo,
 546	const struct xfs_dir_ops *ops,
 547	struct xfs_dir2_data_hdr *hdr,
 548	int			*loghead)
 549{
 550	xfs_dir2_data_entry_t	*dep;		/* active data entry */
 551	xfs_dir2_data_unused_t	*dup;		/* unused data entry */
 552	struct xfs_dir2_data_free *bf;
 553	char			*endp;		/* end of block's data */
 554	char			*p;		/* current entry pointer */
 555
 556	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 557	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 558	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 559	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 560
 561	/*
 562	 * Start by clearing the table.
 563	 */
 564	bf = ops->data_bestfree_p(hdr);
 565	memset(bf, 0, sizeof(*bf) * XFS_DIR2_DATA_FD_COUNT);
 566	*loghead = 1;
 567	/*
 568	 * Set up pointers.
 569	 */
 570	p = (char *)ops->data_entry_p(hdr);
 571	endp = xfs_dir3_data_endp(geo, hdr);
 572	/*
 573	 * Loop over the block's entries.
 574	 */
 575	while (p < endp) {
 576		dup = (xfs_dir2_data_unused_t *)p;
 577		/*
 578		 * If it's a free entry, insert it.
 579		 */
 580		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 581			ASSERT((char *)dup - (char *)hdr ==
 582			       be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
 583			xfs_dir2_data_freeinsert(hdr, bf, dup, loghead);
 584			p += be16_to_cpu(dup->length);
 
 585		}
 
 586		/*
 587		 * For active entries, check their tags and skip them.
 588		 */
 589		else {
 590			dep = (xfs_dir2_data_entry_t *)p;
 591			ASSERT((char *)dep - (char *)hdr ==
 592			       be16_to_cpu(*ops->data_entry_tag_p(dep)));
 593			p += ops->data_entsize(dep->namelen);
 594		}
 595	}
 596}
 597
 598void
 599xfs_dir2_data_freescan(
 600	struct xfs_inode	*dp,
 601	struct xfs_dir2_data_hdr *hdr,
 602	int			*loghead)
 603{
 604	return xfs_dir2_data_freescan_int(dp->i_mount->m_dir_geo, dp->d_ops,
 605			hdr, loghead);
 606}
 607
 608/*
 609 * Initialize a data block at the given block number in the directory.
 610 * Give back the buffer for the created block.
 611 */
 612int						/* error */
 613xfs_dir3_data_init(
 614	xfs_da_args_t		*args,		/* directory operation args */
 615	xfs_dir2_db_t		blkno,		/* logical dir block number */
 616	struct xfs_buf		**bpp)		/* output block buffer */
 617{
 618	struct xfs_buf		*bp;		/* block buffer */
 619	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
 620	xfs_inode_t		*dp;		/* incore directory inode */
 621	xfs_dir2_data_unused_t	*dup;		/* unused entry pointer */
 622	struct xfs_dir2_data_free *bf;
 623	int			error;		/* error return value */
 624	int			i;		/* bestfree index */
 625	xfs_mount_t		*mp;		/* filesystem mount point */
 626	xfs_trans_t		*tp;		/* transaction pointer */
 627	int                     t;              /* temp */
 628
 629	dp = args->dp;
 630	mp = dp->i_mount;
 631	tp = args->trans;
 632	/*
 633	 * Get the buffer set up for the block.
 634	 */
 635	error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(args->geo, blkno),
 636			       -1, &bp, XFS_DATA_FORK);
 637	if (error)
 638		return error;
 639	bp->b_ops = &xfs_dir3_data_buf_ops;
 640	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_DATA_BUF);
 641
 642	/*
 643	 * Initialize the header.
 644	 */
 645	hdr = bp->b_addr;
 646	if (xfs_sb_version_hascrc(&mp->m_sb)) {
 647		struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
 648
 649		memset(hdr3, 0, sizeof(*hdr3));
 650		hdr3->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
 651		hdr3->blkno = cpu_to_be64(bp->b_bn);
 652		hdr3->owner = cpu_to_be64(dp->i_ino);
 653		uuid_copy(&hdr3->uuid, &mp->m_sb.sb_meta_uuid);
 654
 655	} else
 656		hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 657
 658	bf = dp->d_ops->data_bestfree_p(hdr);
 659	bf[0].offset = cpu_to_be16(dp->d_ops->data_entry_offset);
 
 660	for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
 661		bf[i].length = 0;
 662		bf[i].offset = 0;
 663	}
 664
 665	/*
 666	 * Set up an unused entry for the block's body.
 667	 */
 668	dup = dp->d_ops->data_unused_p(hdr);
 669	dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 670
 671	t = args->geo->blksize - (uint)dp->d_ops->data_entry_offset;
 672	bf[0].length = cpu_to_be16(t);
 673	dup->length = cpu_to_be16(t);
 674	*xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
 
 675	/*
 676	 * Log it and return it.
 677	 */
 678	xfs_dir2_data_log_header(args, bp);
 679	xfs_dir2_data_log_unused(args, bp, dup);
 680	*bpp = bp;
 681	return 0;
 682}
 683
 684/*
 685 * Log an active data entry from the block.
 686 */
 687void
 688xfs_dir2_data_log_entry(
 689	struct xfs_da_args	*args,
 690	struct xfs_buf		*bp,
 691	xfs_dir2_data_entry_t	*dep)		/* data entry pointer */
 692{
 
 693	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
 694
 695	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 696	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 697	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 698	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 699
 700	xfs_trans_log_buf(args->trans, bp, (uint)((char *)dep - (char *)hdr),
 701		(uint)((char *)(args->dp->d_ops->data_entry_tag_p(dep) + 1) -
 702		       (char *)hdr - 1));
 703}
 704
 705/*
 706 * Log a data block header.
 707 */
 708void
 709xfs_dir2_data_log_header(
 710	struct xfs_da_args	*args,
 711	struct xfs_buf		*bp)
 712{
 713#ifdef DEBUG
 714	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
 715
 716	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 717	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 718	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 719	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 720#endif
 721
 722	xfs_trans_log_buf(args->trans, bp, 0,
 723			  args->dp->d_ops->data_entry_offset - 1);
 724}
 725
 726/*
 727 * Log a data unused entry.
 728 */
 729void
 730xfs_dir2_data_log_unused(
 731	struct xfs_da_args	*args,
 732	struct xfs_buf		*bp,
 733	xfs_dir2_data_unused_t	*dup)		/* data unused pointer */
 734{
 735	xfs_dir2_data_hdr_t	*hdr = bp->b_addr;
 736
 737	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 738	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 739	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 740	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 741
 742	/*
 743	 * Log the first part of the unused entry.
 744	 */
 745	xfs_trans_log_buf(args->trans, bp, (uint)((char *)dup - (char *)hdr),
 746		(uint)((char *)&dup->length + sizeof(dup->length) -
 747		       1 - (char *)hdr));
 748	/*
 749	 * Log the end (tag) of the unused entry.
 750	 */
 751	xfs_trans_log_buf(args->trans, bp,
 752		(uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
 753		(uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
 754		       sizeof(xfs_dir2_data_off_t) - 1));
 755}
 756
 757/*
 758 * Make a byte range in the data block unused.
 759 * Its current contents are unimportant.
 760 */
 761void
 762xfs_dir2_data_make_free(
 763	struct xfs_da_args	*args,
 764	struct xfs_buf		*bp,
 765	xfs_dir2_data_aoff_t	offset,		/* starting byte offset */
 766	xfs_dir2_data_aoff_t	len,		/* length in bytes */
 767	int			*needlogp,	/* out: log header */
 768	int			*needscanp)	/* out: regen bestfree */
 769{
 770	xfs_dir2_data_hdr_t	*hdr;		/* data block pointer */
 771	xfs_dir2_data_free_t	*dfp;		/* bestfree pointer */
 772	char			*endptr;	/* end of data area */
 773	int			needscan;	/* need to regen bestfree */
 774	xfs_dir2_data_unused_t	*newdup;	/* new unused entry */
 775	xfs_dir2_data_unused_t	*postdup;	/* unused entry after us */
 776	xfs_dir2_data_unused_t	*prevdup;	/* unused entry before us */
 
 777	struct xfs_dir2_data_free *bf;
 778
 779	hdr = bp->b_addr;
 780
 781	/*
 782	 * Figure out where the end of the data area is.
 783	 */
 784	endptr = xfs_dir3_data_endp(args->geo, hdr);
 785	ASSERT(endptr != NULL);
 786
 787	/*
 788	 * If this isn't the start of the block, then back up to
 789	 * the previous entry and see if it's free.
 790	 */
 791	if (offset > args->dp->d_ops->data_entry_offset) {
 792		__be16			*tagp;	/* tag just before us */
 793
 794		tagp = (__be16 *)((char *)hdr + offset) - 1;
 795		prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
 796		if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
 797			prevdup = NULL;
 798	} else
 799		prevdup = NULL;
 800	/*
 801	 * If this isn't the end of the block, see if the entry after
 802	 * us is free.
 803	 */
 804	if ((char *)hdr + offset + len < endptr) {
 805		postdup =
 806			(xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
 807		if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
 808			postdup = NULL;
 809	} else
 810		postdup = NULL;
 811	ASSERT(*needscanp == 0);
 812	needscan = 0;
 813	/*
 814	 * Previous and following entries are both free,
 815	 * merge everything into a single free entry.
 816	 */
 817	bf = args->dp->d_ops->data_bestfree_p(hdr);
 818	if (prevdup && postdup) {
 819		xfs_dir2_data_free_t	*dfp2;	/* another bestfree pointer */
 820
 821		/*
 822		 * See if prevdup and/or postdup are in bestfree table.
 823		 */
 824		dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
 825		dfp2 = xfs_dir2_data_freefind(hdr, bf, postdup);
 826		/*
 827		 * We need a rescan unless there are exactly 2 free entries
 828		 * namely our two.  Then we know what's happening, otherwise
 829		 * since the third bestfree is there, there might be more
 830		 * entries.
 831		 */
 832		needscan = (bf[2].length != 0);
 833		/*
 834		 * Fix up the new big freespace.
 835		 */
 836		be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
 837		*xfs_dir2_data_unused_tag_p(prevdup) =
 838			cpu_to_be16((char *)prevdup - (char *)hdr);
 839		xfs_dir2_data_log_unused(args, bp, prevdup);
 840		if (!needscan) {
 841			/*
 842			 * Has to be the case that entries 0 and 1 are
 843			 * dfp and dfp2 (don't know which is which), and
 844			 * entry 2 is empty.
 845			 * Remove entry 1 first then entry 0.
 846			 */
 847			ASSERT(dfp && dfp2);
 848			if (dfp == &bf[1]) {
 849				dfp = &bf[0];
 850				ASSERT(dfp2 == dfp);
 851				dfp2 = &bf[1];
 852			}
 853			xfs_dir2_data_freeremove(hdr, bf, dfp2, needlogp);
 854			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
 855			/*
 856			 * Now insert the new entry.
 857			 */
 858			dfp = xfs_dir2_data_freeinsert(hdr, bf, prevdup,
 859						       needlogp);
 860			ASSERT(dfp == &bf[0]);
 861			ASSERT(dfp->length == prevdup->length);
 862			ASSERT(!dfp[1].length);
 863			ASSERT(!dfp[2].length);
 864		}
 865	}
 866	/*
 867	 * The entry before us is free, merge with it.
 868	 */
 869	else if (prevdup) {
 870		dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
 871		be16_add_cpu(&prevdup->length, len);
 872		*xfs_dir2_data_unused_tag_p(prevdup) =
 873			cpu_to_be16((char *)prevdup - (char *)hdr);
 874		xfs_dir2_data_log_unused(args, bp, prevdup);
 875		/*
 876		 * If the previous entry was in the table, the new entry
 877		 * is longer, so it will be in the table too.  Remove
 878		 * the old one and add the new one.
 879		 */
 880		if (dfp) {
 881			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
 882			xfs_dir2_data_freeinsert(hdr, bf, prevdup, needlogp);
 883		}
 884		/*
 885		 * Otherwise we need a scan if the new entry is big enough.
 886		 */
 887		else {
 888			needscan = be16_to_cpu(prevdup->length) >
 889				   be16_to_cpu(bf[2].length);
 890		}
 891	}
 892	/*
 893	 * The following entry is free, merge with it.
 894	 */
 895	else if (postdup) {
 896		dfp = xfs_dir2_data_freefind(hdr, bf, postdup);
 897		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
 898		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 899		newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
 900		*xfs_dir2_data_unused_tag_p(newdup) =
 901			cpu_to_be16((char *)newdup - (char *)hdr);
 902		xfs_dir2_data_log_unused(args, bp, newdup);
 903		/*
 904		 * If the following entry was in the table, the new entry
 905		 * is longer, so it will be in the table too.  Remove
 906		 * the old one and add the new one.
 907		 */
 908		if (dfp) {
 909			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
 910			xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
 911		}
 912		/*
 913		 * Otherwise we need a scan if the new entry is big enough.
 914		 */
 915		else {
 916			needscan = be16_to_cpu(newdup->length) >
 917				   be16_to_cpu(bf[2].length);
 918		}
 919	}
 920	/*
 921	 * Neither neighbor is free.  Make a new entry.
 922	 */
 923	else {
 924		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
 925		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 926		newdup->length = cpu_to_be16(len);
 927		*xfs_dir2_data_unused_tag_p(newdup) =
 928			cpu_to_be16((char *)newdup - (char *)hdr);
 929		xfs_dir2_data_log_unused(args, bp, newdup);
 930		xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
 931	}
 932	*needscanp = needscan;
 933}
 934
 935/* Check our free data for obvious signs of corruption. */
 936static inline xfs_failaddr_t
 937xfs_dir2_data_check_free(
 938	struct xfs_dir2_data_hdr	*hdr,
 939	struct xfs_dir2_data_unused	*dup,
 940	xfs_dir2_data_aoff_t		offset,
 941	xfs_dir2_data_aoff_t		len)
 942{
 943	if (hdr->magic != cpu_to_be32(XFS_DIR2_DATA_MAGIC) &&
 944	    hdr->magic != cpu_to_be32(XFS_DIR3_DATA_MAGIC) &&
 945	    hdr->magic != cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) &&
 946	    hdr->magic != cpu_to_be32(XFS_DIR3_BLOCK_MAGIC))
 947		return __this_address;
 948	if (be16_to_cpu(dup->freetag) != XFS_DIR2_DATA_FREE_TAG)
 949		return __this_address;
 950	if (offset < (char *)dup - (char *)hdr)
 951		return __this_address;
 952	if (offset + len > (char *)dup + be16_to_cpu(dup->length) - (char *)hdr)
 953		return __this_address;
 954	if ((char *)dup - (char *)hdr !=
 955			be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)))
 956		return __this_address;
 957	return NULL;
 958}
 959
 960/* Sanity-check a new bestfree entry. */
 961static inline xfs_failaddr_t
 962xfs_dir2_data_check_new_free(
 963	struct xfs_dir2_data_hdr	*hdr,
 964	struct xfs_dir2_data_free	*dfp,
 965	struct xfs_dir2_data_unused	*newdup)
 966{
 967	if (dfp == NULL)
 968		return __this_address;
 969	if (dfp->length != newdup->length)
 970		return __this_address;
 971	if (be16_to_cpu(dfp->offset) != (char *)newdup - (char *)hdr)
 972		return __this_address;
 973	return NULL;
 974}
 975
 976/*
 977 * Take a byte range out of an existing unused space and make it un-free.
 978 */
 979int
 980xfs_dir2_data_use_free(
 981	struct xfs_da_args	*args,
 982	struct xfs_buf		*bp,
 983	xfs_dir2_data_unused_t	*dup,		/* unused entry */
 984	xfs_dir2_data_aoff_t	offset,		/* starting offset to use */
 985	xfs_dir2_data_aoff_t	len,		/* length to use */
 986	int			*needlogp,	/* out: need to log header */
 987	int			*needscanp)	/* out: need regen bestfree */
 988{
 989	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
 990	xfs_dir2_data_free_t	*dfp;		/* bestfree pointer */
 991	xfs_dir2_data_unused_t	*newdup;	/* new unused entry */
 992	xfs_dir2_data_unused_t	*newdup2;	/* another new unused entry */
 993	struct xfs_dir2_data_free *bf;
 994	xfs_failaddr_t		fa;
 995	int			matchback;	/* matches end of freespace */
 996	int			matchfront;	/* matches start of freespace */
 997	int			needscan;	/* need to regen bestfree */
 998	int			oldlen;		/* old unused entry's length */
 999
1000	hdr = bp->b_addr;
1001	fa = xfs_dir2_data_check_free(hdr, dup, offset, len);
1002	if (fa)
1003		goto corrupt;
1004	/*
1005	 * Look up the entry in the bestfree table.
1006	 */
1007	oldlen = be16_to_cpu(dup->length);
1008	bf = args->dp->d_ops->data_bestfree_p(hdr);
1009	dfp = xfs_dir2_data_freefind(hdr, bf, dup);
1010	ASSERT(dfp || oldlen <= be16_to_cpu(bf[2].length));
1011	/*
1012	 * Check for alignment with front and back of the entry.
1013	 */
1014	matchfront = (char *)dup - (char *)hdr == offset;
1015	matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
1016	ASSERT(*needscanp == 0);
1017	needscan = 0;
1018	/*
1019	 * If we matched it exactly we just need to get rid of it from
1020	 * the bestfree table.
1021	 */
1022	if (matchfront && matchback) {
1023		if (dfp) {
1024			needscan = (bf[2].offset != 0);
1025			if (!needscan)
1026				xfs_dir2_data_freeremove(hdr, bf, dfp,
1027							 needlogp);
1028		}
1029	}
1030	/*
1031	 * We match the first part of the entry.
1032	 * Make a new entry with the remaining freespace.
1033	 */
1034	else if (matchfront) {
1035		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
1036		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1037		newdup->length = cpu_to_be16(oldlen - len);
1038		*xfs_dir2_data_unused_tag_p(newdup) =
1039			cpu_to_be16((char *)newdup - (char *)hdr);
1040		xfs_dir2_data_log_unused(args, bp, newdup);
1041		/*
1042		 * If it was in the table, remove it and add the new one.
1043		 */
1044		if (dfp) {
1045			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
1046			dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
1047						       needlogp);
1048			fa = xfs_dir2_data_check_new_free(hdr, dfp, newdup);
1049			if (fa)
1050				goto corrupt;
1051			/*
1052			 * If we got inserted at the last slot,
1053			 * that means we don't know if there was a better
1054			 * choice for the last slot, or not.  Rescan.
1055			 */
1056			needscan = dfp == &bf[2];
1057		}
1058	}
1059	/*
1060	 * We match the last part of the entry.
1061	 * Trim the allocated space off the tail of the entry.
1062	 */
1063	else if (matchback) {
1064		newdup = dup;
1065		newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
1066		*xfs_dir2_data_unused_tag_p(newdup) =
1067			cpu_to_be16((char *)newdup - (char *)hdr);
1068		xfs_dir2_data_log_unused(args, bp, newdup);
1069		/*
1070		 * If it was in the table, remove it and add the new one.
1071		 */
1072		if (dfp) {
1073			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
1074			dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
1075						       needlogp);
1076			fa = xfs_dir2_data_check_new_free(hdr, dfp, newdup);
1077			if (fa)
1078				goto corrupt;
1079			/*
1080			 * If we got inserted at the last slot,
1081			 * that means we don't know if there was a better
1082			 * choice for the last slot, or not.  Rescan.
1083			 */
1084			needscan = dfp == &bf[2];
1085		}
1086	}
1087	/*
1088	 * Poking out the middle of an entry.
1089	 * Make two new entries.
1090	 */
1091	else {
1092		newdup = dup;
1093		newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
1094		*xfs_dir2_data_unused_tag_p(newdup) =
1095			cpu_to_be16((char *)newdup - (char *)hdr);
1096		xfs_dir2_data_log_unused(args, bp, newdup);
1097		newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
1098		newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1099		newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
1100		*xfs_dir2_data_unused_tag_p(newdup2) =
1101			cpu_to_be16((char *)newdup2 - (char *)hdr);
1102		xfs_dir2_data_log_unused(args, bp, newdup2);
1103		/*
1104		 * If the old entry was in the table, we need to scan
1105		 * if the 3rd entry was valid, since these entries
1106		 * are smaller than the old one.
1107		 * If we don't need to scan that means there were 1 or 2
1108		 * entries in the table, and removing the old and adding
1109		 * the 2 new will work.
1110		 */
1111		if (dfp) {
1112			needscan = (bf[2].length != 0);
1113			if (!needscan) {
1114				xfs_dir2_data_freeremove(hdr, bf, dfp,
1115							 needlogp);
1116				xfs_dir2_data_freeinsert(hdr, bf, newdup,
1117							 needlogp);
1118				xfs_dir2_data_freeinsert(hdr, bf, newdup2,
1119							 needlogp);
1120			}
1121		}
1122	}
1123	*needscanp = needscan;
1124	return 0;
1125corrupt:
1126	xfs_corruption_error(__func__, XFS_ERRLEVEL_LOW, args->dp->i_mount,
1127			hdr, __FILE__, __LINE__, fa);
 
1128	return -EFSCORRUPTED;
1129}
1130
1131/* Find the end of the entry data in a data/block format dir block. */
1132void *
1133xfs_dir3_data_endp(
1134	struct xfs_da_geometry		*geo,
1135	struct xfs_dir2_data_hdr	*hdr)
1136{
 
 
1137	switch (hdr->magic) {
1138	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
1139	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
1140		return xfs_dir2_block_leaf_p(xfs_dir2_block_tail_p(geo, hdr));
 
1141	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
1142	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
1143		return (char *)hdr + geo->blksize;
1144	default:
1145		return NULL;
1146	}
1147}
v6.9.4
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2000-2002,2005 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_dir2.h"
  16#include "xfs_dir2_priv.h"
  17#include "xfs_error.h"
  18#include "xfs_trans.h"
  19#include "xfs_buf_item.h"
 
  20#include "xfs_log.h"
  21#include "xfs_health.h"
  22
  23static xfs_failaddr_t xfs_dir2_data_freefind_verify(
  24		struct xfs_dir2_data_hdr *hdr, struct xfs_dir2_data_free *bf,
  25		struct xfs_dir2_data_unused *dup,
  26		struct xfs_dir2_data_free **bf_ent);
  27
  28struct xfs_dir2_data_free *
  29xfs_dir2_data_bestfree_p(
  30	struct xfs_mount		*mp,
  31	struct xfs_dir2_data_hdr	*hdr)
  32{
  33	if (xfs_has_crc(mp))
  34		return ((struct xfs_dir3_data_hdr *)hdr)->best_free;
  35	return hdr->bestfree;
  36}
  37
  38/*
  39 * Pointer to an entry's tag word.
  40 */
  41__be16 *
  42xfs_dir2_data_entry_tag_p(
  43	struct xfs_mount		*mp,
  44	struct xfs_dir2_data_entry	*dep)
  45{
  46	return (__be16 *)((char *)dep +
  47		xfs_dir2_data_entsize(mp, dep->namelen) - sizeof(__be16));
  48}
  49
  50uint8_t
  51xfs_dir2_data_get_ftype(
  52	struct xfs_mount		*mp,
  53	struct xfs_dir2_data_entry	*dep)
  54{
  55	if (xfs_has_ftype(mp)) {
  56		uint8_t			ftype = dep->name[dep->namelen];
  57
  58		if (likely(ftype < XFS_DIR3_FT_MAX))
  59			return ftype;
  60	}
  61
  62	return XFS_DIR3_FT_UNKNOWN;
  63}
  64
  65void
  66xfs_dir2_data_put_ftype(
  67	struct xfs_mount		*mp,
  68	struct xfs_dir2_data_entry	*dep,
  69	uint8_t				ftype)
  70{
  71	ASSERT(ftype < XFS_DIR3_FT_MAX);
  72	ASSERT(dep->namelen != 0);
  73
  74	if (xfs_has_ftype(mp))
  75		dep->name[dep->namelen] = ftype;
  76}
  77
  78/*
  79 * The number of leaf entries is limited by the size of the block and the amount
  80 * of space used by the data entries.  We don't know how much space is used by
  81 * the data entries yet, so just ensure that the count falls somewhere inside
  82 * the block right now.
  83 */
  84static inline unsigned int
  85xfs_dir2_data_max_leaf_entries(
  86	struct xfs_da_geometry		*geo)
  87{
  88	return (geo->blksize - sizeof(struct xfs_dir2_block_tail) -
  89		geo->data_entry_offset) /
  90			sizeof(struct xfs_dir2_leaf_entry);
  91}
  92
  93/*
  94 * Check the consistency of the data block.
  95 * The input can also be a block-format directory.
  96 * Return NULL if the buffer is good, otherwise the address of the error.
  97 */
  98xfs_failaddr_t
  99__xfs_dir3_data_check(
 100	struct xfs_inode	*dp,		/* incore inode pointer */
 101	struct xfs_buf		*bp)		/* data block's buffer */
 102{
 103	xfs_dir2_dataptr_t	addr;		/* addr for leaf lookup */
 104	xfs_dir2_data_free_t	*bf;		/* bestfree table */
 105	xfs_dir2_block_tail_t	*btp=NULL;	/* block tail */
 106	int			count;		/* count of entries found */
 107	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
 
 108	xfs_dir2_data_free_t	*dfp;		/* bestfree entry */
 
 
 109	int			freeseen;	/* mask of bestfrees seen */
 110	xfs_dahash_t		hash;		/* hash of current name */
 111	int			i;		/* leaf index */
 112	int			lastfree;	/* last entry was unused */
 113	xfs_dir2_leaf_entry_t	*lep=NULL;	/* block leaf entries */
 114	struct xfs_mount	*mp = bp->b_mount;
 
 115	int			stale;		/* count of stale leaves */
 116	struct xfs_name		name;
 117	unsigned int		offset;
 118	unsigned int		end;
 119	struct xfs_da_geometry	*geo = mp->m_dir_geo;
 
 
 
 
 
 
 
 
 120
 121	/*
 122	 * If this isn't a directory, something is seriously wrong.  Bail out.
 
 123	 */
 124	if (dp && !S_ISDIR(VFS_I(dp)->i_mode))
 
 125		return __this_address;
 126
 127	hdr = bp->b_addr;
 128	offset = geo->data_entry_offset;
 129
 130	switch (hdr->magic) {
 131	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
 132	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
 133		btp = xfs_dir2_block_tail_p(geo, hdr);
 134		lep = xfs_dir2_block_leaf_p(btp);
 135
 
 
 
 
 
 
 
 136		if (be32_to_cpu(btp->count) >=
 137		    xfs_dir2_data_max_leaf_entries(geo))
 138			return __this_address;
 139		break;
 140	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
 141	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
 142		break;
 143	default:
 144		return __this_address;
 145	}
 146	end = xfs_dir3_data_end_offset(geo, hdr);
 147	if (!end)
 148		return __this_address;
 149
 150	/*
 151	 * Account for zero bestfree entries.
 152	 */
 153	bf = xfs_dir2_data_bestfree_p(mp, hdr);
 154	count = lastfree = freeseen = 0;
 155	if (!bf[0].length) {
 156		if (bf[0].offset)
 157			return __this_address;
 158		freeseen |= 1 << 0;
 159	}
 160	if (!bf[1].length) {
 161		if (bf[1].offset)
 162			return __this_address;
 163		freeseen |= 1 << 1;
 164	}
 165	if (!bf[2].length) {
 166		if (bf[2].offset)
 167			return __this_address;
 168		freeseen |= 1 << 2;
 169	}
 170
 171	if (be16_to_cpu(bf[0].length) < be16_to_cpu(bf[1].length))
 172		return __this_address;
 173	if (be16_to_cpu(bf[1].length) < be16_to_cpu(bf[2].length))
 174		return __this_address;
 175	/*
 176	 * Loop over the data/unused entries.
 177	 */
 178	while (offset < end) {
 179		struct xfs_dir2_data_unused	*dup = bp->b_addr + offset;
 180		struct xfs_dir2_data_entry	*dep = bp->b_addr + offset;
 181
 182		/*
 183		 * If it's unused, look for the space in the bestfree table.
 184		 * If we find it, account for that, else make sure it
 185		 * doesn't need to be there.
 186		 */
 187		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 188			xfs_failaddr_t	fa;
 189
 190			if (lastfree != 0)
 191				return __this_address;
 192			if (offset + be16_to_cpu(dup->length) > end)
 193				return __this_address;
 194			if (be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) !=
 195			    offset)
 196				return __this_address;
 197			fa = xfs_dir2_data_freefind_verify(hdr, bf, dup, &dfp);
 198			if (fa)
 199				return fa;
 200			if (dfp) {
 201				i = (int)(dfp - bf);
 202				if ((freeseen & (1 << i)) != 0)
 203					return __this_address;
 204				freeseen |= 1 << i;
 205			} else {
 206				if (be16_to_cpu(dup->length) >
 207				    be16_to_cpu(bf[2].length))
 208					return __this_address;
 209			}
 210			offset += be16_to_cpu(dup->length);
 211			lastfree = 1;
 212			continue;
 213		}
 214		/*
 215		 * It's a real entry.  Validate the fields.
 216		 * If this is a block directory then make sure it's
 217		 * in the leaf section of the block.
 218		 * The linear search is crude but this is DEBUG code.
 219		 */
 
 220		if (dep->namelen == 0)
 221			return __this_address;
 222		if (!xfs_verify_dir_ino(mp, be64_to_cpu(dep->inumber)))
 223			return __this_address;
 224		if (offset + xfs_dir2_data_entsize(mp, dep->namelen) > end)
 225			return __this_address;
 226		if (be16_to_cpu(*xfs_dir2_data_entry_tag_p(mp, dep)) != offset)
 
 227			return __this_address;
 228		if (xfs_dir2_data_get_ftype(mp, dep) >= XFS_DIR3_FT_MAX)
 229			return __this_address;
 230		count++;
 231		lastfree = 0;
 232		if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 233		    hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
 234			addr = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
 235						(xfs_dir2_data_aoff_t)
 236						((char *)dep - (char *)hdr));
 237			name.name = dep->name;
 238			name.len = dep->namelen;
 239			hash = xfs_dir2_hashname(mp, &name);
 240			for (i = 0; i < be32_to_cpu(btp->count); i++) {
 241				if (be32_to_cpu(lep[i].address) == addr &&
 242				    be32_to_cpu(lep[i].hashval) == hash)
 243					break;
 244			}
 245			if (i >= be32_to_cpu(btp->count))
 246				return __this_address;
 247		}
 248		offset += xfs_dir2_data_entsize(mp, dep->namelen);
 249	}
 250	/*
 251	 * Need to have seen all the entries and all the bestfree slots.
 252	 */
 253	if (freeseen != 7)
 254		return __this_address;
 255	if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 256	    hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
 257		for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
 258			if (lep[i].address ==
 259			    cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 260				stale++;
 261			if (i > 0 && be32_to_cpu(lep[i].hashval) <
 262				     be32_to_cpu(lep[i - 1].hashval))
 263				return __this_address;
 264		}
 265		if (count != be32_to_cpu(btp->count) - be32_to_cpu(btp->stale))
 266			return __this_address;
 267		if (stale != be32_to_cpu(btp->stale))
 268			return __this_address;
 269	}
 270	return NULL;
 271}
 272
 273#ifdef DEBUG
 274void
 275xfs_dir3_data_check(
 276	struct xfs_inode	*dp,
 277	struct xfs_buf		*bp)
 278{
 279	xfs_failaddr_t		fa;
 280
 281	fa = __xfs_dir3_data_check(dp, bp);
 282	if (!fa)
 283		return;
 284	xfs_corruption_error(__func__, XFS_ERRLEVEL_LOW, dp->i_mount,
 285			bp->b_addr, BBTOB(bp->b_length), __FILE__, __LINE__,
 286			fa);
 287	ASSERT(0);
 288}
 289#endif
 290
 291static xfs_failaddr_t
 292xfs_dir3_data_verify(
 293	struct xfs_buf		*bp)
 294{
 295	struct xfs_mount	*mp = bp->b_mount;
 296	struct xfs_dir3_blk_hdr	*hdr3 = bp->b_addr;
 297
 298	if (!xfs_verify_magic(bp, hdr3->magic))
 299		return __this_address;
 300
 301	if (xfs_has_crc(mp)) {
 302		if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_meta_uuid))
 303			return __this_address;
 304		if (be64_to_cpu(hdr3->blkno) != xfs_buf_daddr(bp))
 305			return __this_address;
 306		if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->lsn)))
 307			return __this_address;
 
 
 
 308	}
 309	return __xfs_dir3_data_check(NULL, bp);
 310}
 311
 312/*
 313 * Readahead of the first block of the directory when it is opened is completely
 314 * oblivious to the format of the directory. Hence we can either get a block
 315 * format buffer or a data format buffer on readahead.
 316 */
 317static void
 318xfs_dir3_data_reada_verify(
 319	struct xfs_buf		*bp)
 320{
 321	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
 322
 323	switch (hdr->magic) {
 324	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
 325	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
 326		bp->b_ops = &xfs_dir3_block_buf_ops;
 327		bp->b_ops->verify_read(bp);
 328		return;
 329	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
 330	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
 331		bp->b_ops = &xfs_dir3_data_buf_ops;
 332		bp->b_ops->verify_read(bp);
 333		return;
 334	default:
 335		xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
 336		break;
 337	}
 338}
 339
 340static void
 341xfs_dir3_data_read_verify(
 342	struct xfs_buf	*bp)
 343{
 344	struct xfs_mount	*mp = bp->b_mount;
 345	xfs_failaddr_t		fa;
 346
 347	if (xfs_has_crc(mp) &&
 348	    !xfs_buf_verify_cksum(bp, XFS_DIR3_DATA_CRC_OFF))
 349		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 350	else {
 351		fa = xfs_dir3_data_verify(bp);
 352		if (fa)
 353			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 354	}
 355}
 356
 357static void
 358xfs_dir3_data_write_verify(
 359	struct xfs_buf	*bp)
 360{
 361	struct xfs_mount	*mp = bp->b_mount;
 362	struct xfs_buf_log_item	*bip = bp->b_log_item;
 363	struct xfs_dir3_blk_hdr	*hdr3 = bp->b_addr;
 364	xfs_failaddr_t		fa;
 365
 366	fa = xfs_dir3_data_verify(bp);
 367	if (fa) {
 368		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 369		return;
 370	}
 371
 372	if (!xfs_has_crc(mp))
 373		return;
 374
 375	if (bip)
 376		hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
 377
 378	xfs_buf_update_cksum(bp, XFS_DIR3_DATA_CRC_OFF);
 379}
 380
 381const struct xfs_buf_ops xfs_dir3_data_buf_ops = {
 382	.name = "xfs_dir3_data",
 383	.magic = { cpu_to_be32(XFS_DIR2_DATA_MAGIC),
 384		   cpu_to_be32(XFS_DIR3_DATA_MAGIC) },
 385	.verify_read = xfs_dir3_data_read_verify,
 386	.verify_write = xfs_dir3_data_write_verify,
 387	.verify_struct = xfs_dir3_data_verify,
 388};
 389
 390static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
 391	.name = "xfs_dir3_data_reada",
 392	.magic = { cpu_to_be32(XFS_DIR2_DATA_MAGIC),
 393		   cpu_to_be32(XFS_DIR3_DATA_MAGIC) },
 394	.verify_read = xfs_dir3_data_reada_verify,
 395	.verify_write = xfs_dir3_data_write_verify,
 396};
 397
 398static xfs_failaddr_t
 399xfs_dir3_data_header_check(
 400	struct xfs_inode	*dp,
 401	struct xfs_buf		*bp)
 402{
 403	struct xfs_mount	*mp = dp->i_mount;
 404
 405	if (xfs_has_crc(mp)) {
 406		struct xfs_dir3_data_hdr *hdr3 = bp->b_addr;
 407
 408		if (be64_to_cpu(hdr3->hdr.owner) != dp->i_ino)
 409			return __this_address;
 410	}
 411
 412	return NULL;
 413}
 414
 415int
 416xfs_dir3_data_read(
 417	struct xfs_trans	*tp,
 418	struct xfs_inode	*dp,
 419	xfs_dablk_t		bno,
 420	unsigned int		flags,
 421	struct xfs_buf		**bpp)
 422{
 423	xfs_failaddr_t		fa;
 424	int			err;
 425
 426	err = xfs_da_read_buf(tp, dp, bno, flags, bpp, XFS_DATA_FORK,
 427			&xfs_dir3_data_buf_ops);
 428	if (err || !*bpp)
 429		return err;
 430
 431	/* Check things that we can't do in the verifier. */
 432	fa = xfs_dir3_data_header_check(dp, *bpp);
 433	if (fa) {
 434		__xfs_buf_mark_corrupt(*bpp, fa);
 435		xfs_trans_brelse(tp, *bpp);
 436		*bpp = NULL;
 437		xfs_dirattr_mark_sick(dp, XFS_DATA_FORK);
 438		return -EFSCORRUPTED;
 439	}
 440
 441	xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
 442	return err;
 443}
 444
 445int
 446xfs_dir3_data_readahead(
 447	struct xfs_inode	*dp,
 448	xfs_dablk_t		bno,
 449	unsigned int		flags)
 450{
 451	return xfs_da_reada_buf(dp, bno, flags, XFS_DATA_FORK,
 452				&xfs_dir3_data_reada_buf_ops);
 453}
 454
 455/*
 456 * Find the bestfree entry that exactly coincides with unused directory space
 457 * or a verifier error because the bestfree data are bad.
 458 */
 459static xfs_failaddr_t
 460xfs_dir2_data_freefind_verify(
 461	struct xfs_dir2_data_hdr	*hdr,
 462	struct xfs_dir2_data_free	*bf,
 463	struct xfs_dir2_data_unused	*dup,
 464	struct xfs_dir2_data_free	**bf_ent)
 465{
 466	struct xfs_dir2_data_free	*dfp;
 467	xfs_dir2_data_aoff_t		off;
 468	bool				matched = false;
 469	bool				seenzero = false;
 
 
 470
 471	*bf_ent = NULL;
 472	off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
 473
 
 474	/*
 475	 * Validate some consistency in the bestfree table.
 476	 * Check order, non-overlapping entries, and if we find the
 477	 * one we're looking for it has to be exact.
 478	 */
 479	for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
 
 
 
 
 
 
 480		if (!dfp->offset) {
 481			if (dfp->length)
 482				return __this_address;
 483			seenzero = true;
 484			continue;
 485		}
 486		if (seenzero)
 487			return __this_address;
 488		if (be16_to_cpu(dfp->offset) == off) {
 489			matched = true;
 490			if (dfp->length != dup->length)
 491				return __this_address;
 492		} else if (be16_to_cpu(dfp->offset) > off) {
 493			if (off + be16_to_cpu(dup->length) >
 494					be16_to_cpu(dfp->offset))
 495				return __this_address;
 496		} else {
 497			if (be16_to_cpu(dfp->offset) +
 498					be16_to_cpu(dfp->length) > off)
 499				return __this_address;
 500		}
 501		if (!matched &&
 502		    be16_to_cpu(dfp->length) < be16_to_cpu(dup->length))
 503			return __this_address;
 504		if (dfp > &bf[0] &&
 505		    be16_to_cpu(dfp[-1].length) < be16_to_cpu(dfp[0].length))
 506			return __this_address;
 507	}
 508
 509	/* Looks ok so far; now try to match up with a bestfree entry. */
 510	*bf_ent = xfs_dir2_data_freefind(hdr, bf, dup);
 511	return NULL;
 512}
 513
 514/*
 515 * Given a data block and an unused entry from that block,
 516 * return the bestfree entry if any that corresponds to it.
 517 */
 518xfs_dir2_data_free_t *
 519xfs_dir2_data_freefind(
 520	struct xfs_dir2_data_hdr *hdr,		/* data block header */
 521	struct xfs_dir2_data_free *bf,		/* bestfree table pointer */
 522	struct xfs_dir2_data_unused *dup)	/* unused space */
 523{
 524	xfs_dir2_data_free_t	*dfp;		/* bestfree entry */
 525	xfs_dir2_data_aoff_t	off;		/* offset value needed */
 526
 527	off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
 528
 529	/*
 530	 * If this is smaller than the smallest bestfree entry,
 531	 * it can't be there since they're sorted.
 532	 */
 533	if (be16_to_cpu(dup->length) <
 534	    be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
 535		return NULL;
 536	/*
 537	 * Look at the three bestfree entries for our guy.
 538	 */
 539	for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
 540		if (!dfp->offset)
 541			return NULL;
 542		if (be16_to_cpu(dfp->offset) == off)
 543			return dfp;
 544	}
 545	/*
 546	 * Didn't find it.  This only happens if there are duplicate lengths.
 547	 */
 548	return NULL;
 549}
 550
 551/*
 552 * Insert an unused-space entry into the bestfree table.
 553 */
 554xfs_dir2_data_free_t *				/* entry inserted */
 555xfs_dir2_data_freeinsert(
 556	struct xfs_dir2_data_hdr *hdr,		/* data block pointer */
 557	struct xfs_dir2_data_free *dfp,		/* bestfree table pointer */
 558	struct xfs_dir2_data_unused *dup,	/* unused space */
 559	int			*loghead)	/* log the data header (out) */
 560{
 561	xfs_dir2_data_free_t	new;		/* new bestfree entry */
 562
 563	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 564	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 565	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 566	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 567
 568	new.length = dup->length;
 569	new.offset = cpu_to_be16((char *)dup - (char *)hdr);
 570
 571	/*
 572	 * Insert at position 0, 1, or 2; or not at all.
 573	 */
 574	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
 575		dfp[2] = dfp[1];
 576		dfp[1] = dfp[0];
 577		dfp[0] = new;
 578		*loghead = 1;
 579		return &dfp[0];
 580	}
 581	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
 582		dfp[2] = dfp[1];
 583		dfp[1] = new;
 584		*loghead = 1;
 585		return &dfp[1];
 586	}
 587	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
 588		dfp[2] = new;
 589		*loghead = 1;
 590		return &dfp[2];
 591	}
 592	return NULL;
 593}
 594
 595/*
 596 * Remove a bestfree entry from the table.
 597 */
 598STATIC void
 599xfs_dir2_data_freeremove(
 600	struct xfs_dir2_data_hdr *hdr,		/* data block header */
 601	struct xfs_dir2_data_free *bf,		/* bestfree table pointer */
 602	struct xfs_dir2_data_free *dfp,		/* bestfree entry pointer */
 603	int			*loghead)	/* out: log data header */
 604{
 605
 606	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 607	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 608	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 609	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 610
 611	/*
 612	 * It's the first entry, slide the next 2 up.
 613	 */
 614	if (dfp == &bf[0]) {
 615		bf[0] = bf[1];
 616		bf[1] = bf[2];
 617	}
 618	/*
 619	 * It's the second entry, slide the 3rd entry up.
 620	 */
 621	else if (dfp == &bf[1])
 622		bf[1] = bf[2];
 623	/*
 624	 * Must be the last entry.
 625	 */
 626	else
 627		ASSERT(dfp == &bf[2]);
 628	/*
 629	 * Clear the 3rd entry, must be zero now.
 630	 */
 631	bf[2].length = 0;
 632	bf[2].offset = 0;
 633	*loghead = 1;
 634}
 635
 636/*
 637 * Given a data block, reconstruct its bestfree map.
 638 */
 639void
 640xfs_dir2_data_freescan(
 641	struct xfs_mount		*mp,
 642	struct xfs_dir2_data_hdr	*hdr,
 643	int				*loghead)
 
 644{
 645	struct xfs_da_geometry		*geo = mp->m_dir_geo;
 646	struct xfs_dir2_data_free	*bf = xfs_dir2_data_bestfree_p(mp, hdr);
 647	void				*addr = hdr;
 648	unsigned int			offset = geo->data_entry_offset;
 649	unsigned int			end;
 650
 651	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 652	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 653	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 654	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 655
 656	/*
 657	 * Start by clearing the table.
 658	 */
 
 659	memset(bf, 0, sizeof(*bf) * XFS_DIR2_DATA_FD_COUNT);
 660	*loghead = 1;
 661
 662	end = xfs_dir3_data_end_offset(geo, addr);
 663	while (offset < end) {
 664		struct xfs_dir2_data_unused	*dup = addr + offset;
 665		struct xfs_dir2_data_entry	*dep = addr + offset;
 666
 
 
 
 
 667		/*
 668		 * If it's a free entry, insert it.
 669		 */
 670		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 671			ASSERT(offset ==
 672			       be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
 673			xfs_dir2_data_freeinsert(hdr, bf, dup, loghead);
 674			offset += be16_to_cpu(dup->length);
 675			continue;
 676		}
 677
 678		/*
 679		 * For active entries, check their tags and skip them.
 680		 */
 681		ASSERT(offset ==
 682		       be16_to_cpu(*xfs_dir2_data_entry_tag_p(mp, dep)));
 683		offset += xfs_dir2_data_entsize(mp, dep->namelen);
 
 
 
 684	}
 685}
 686
 
 
 
 
 
 
 
 
 
 
 687/*
 688 * Initialize a data block at the given block number in the directory.
 689 * Give back the buffer for the created block.
 690 */
 691int						/* error */
 692xfs_dir3_data_init(
 693	struct xfs_da_args		*args,	/* directory operation args */
 694	xfs_dir2_db_t			blkno,	/* logical dir block number */
 695	struct xfs_buf			**bpp)	/* output block buffer */
 696{
 697	struct xfs_trans		*tp = args->trans;
 698	struct xfs_inode		*dp = args->dp;
 699	struct xfs_mount		*mp = dp->i_mount;
 700	struct xfs_da_geometry		*geo = args->geo;
 701	struct xfs_buf			*bp;
 702	struct xfs_dir2_data_hdr	*hdr;
 703	struct xfs_dir2_data_unused	*dup;
 704	struct xfs_dir2_data_free 	*bf;
 705	int				error;
 706	int				i;
 707
 
 
 
 708	/*
 709	 * Get the buffer set up for the block.
 710	 */
 711	error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(args->geo, blkno),
 712			       &bp, XFS_DATA_FORK);
 713	if (error)
 714		return error;
 715	bp->b_ops = &xfs_dir3_data_buf_ops;
 716	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_DATA_BUF);
 717
 718	/*
 719	 * Initialize the header.
 720	 */
 721	hdr = bp->b_addr;
 722	if (xfs_has_crc(mp)) {
 723		struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
 724
 725		memset(hdr3, 0, sizeof(*hdr3));
 726		hdr3->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
 727		hdr3->blkno = cpu_to_be64(xfs_buf_daddr(bp));
 728		hdr3->owner = cpu_to_be64(dp->i_ino);
 729		uuid_copy(&hdr3->uuid, &mp->m_sb.sb_meta_uuid);
 730
 731	} else
 732		hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 733
 734	bf = xfs_dir2_data_bestfree_p(mp, hdr);
 735	bf[0].offset = cpu_to_be16(geo->data_entry_offset);
 736	bf[0].length = cpu_to_be16(geo->blksize - geo->data_entry_offset);
 737	for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
 738		bf[i].length = 0;
 739		bf[i].offset = 0;
 740	}
 741
 742	/*
 743	 * Set up an unused entry for the block's body.
 744	 */
 745	dup = bp->b_addr + geo->data_entry_offset;
 746	dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 747	dup->length = bf[0].length;
 
 
 
 748	*xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
 749
 750	/*
 751	 * Log it and return it.
 752	 */
 753	xfs_dir2_data_log_header(args, bp);
 754	xfs_dir2_data_log_unused(args, bp, dup);
 755	*bpp = bp;
 756	return 0;
 757}
 758
 759/*
 760 * Log an active data entry from the block.
 761 */
 762void
 763xfs_dir2_data_log_entry(
 764	struct xfs_da_args	*args,
 765	struct xfs_buf		*bp,
 766	xfs_dir2_data_entry_t	*dep)		/* data entry pointer */
 767{
 768	struct xfs_mount	*mp = bp->b_mount;
 769	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
 770
 771	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 772	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 773	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 774	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 775
 776	xfs_trans_log_buf(args->trans, bp, (uint)((char *)dep - (char *)hdr),
 777		(uint)((char *)(xfs_dir2_data_entry_tag_p(mp, dep) + 1) -
 778		       (char *)hdr - 1));
 779}
 780
 781/*
 782 * Log a data block header.
 783 */
 784void
 785xfs_dir2_data_log_header(
 786	struct xfs_da_args	*args,
 787	struct xfs_buf		*bp)
 788{
 789#ifdef DEBUG
 790	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
 791
 792	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 793	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 794	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 795	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 796#endif
 797
 798	xfs_trans_log_buf(args->trans, bp, 0, args->geo->data_entry_offset - 1);
 
 799}
 800
 801/*
 802 * Log a data unused entry.
 803 */
 804void
 805xfs_dir2_data_log_unused(
 806	struct xfs_da_args	*args,
 807	struct xfs_buf		*bp,
 808	xfs_dir2_data_unused_t	*dup)		/* data unused pointer */
 809{
 810	xfs_dir2_data_hdr_t	*hdr = bp->b_addr;
 811
 812	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
 813	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
 814	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
 815	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
 816
 817	/*
 818	 * Log the first part of the unused entry.
 819	 */
 820	xfs_trans_log_buf(args->trans, bp, (uint)((char *)dup - (char *)hdr),
 821		(uint)((char *)&dup->length + sizeof(dup->length) -
 822		       1 - (char *)hdr));
 823	/*
 824	 * Log the end (tag) of the unused entry.
 825	 */
 826	xfs_trans_log_buf(args->trans, bp,
 827		(uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
 828		(uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
 829		       sizeof(xfs_dir2_data_off_t) - 1));
 830}
 831
 832/*
 833 * Make a byte range in the data block unused.
 834 * Its current contents are unimportant.
 835 */
 836void
 837xfs_dir2_data_make_free(
 838	struct xfs_da_args	*args,
 839	struct xfs_buf		*bp,
 840	xfs_dir2_data_aoff_t	offset,		/* starting byte offset */
 841	xfs_dir2_data_aoff_t	len,		/* length in bytes */
 842	int			*needlogp,	/* out: log header */
 843	int			*needscanp)	/* out: regen bestfree */
 844{
 845	xfs_dir2_data_hdr_t	*hdr;		/* data block pointer */
 846	xfs_dir2_data_free_t	*dfp;		/* bestfree pointer */
 
 847	int			needscan;	/* need to regen bestfree */
 848	xfs_dir2_data_unused_t	*newdup;	/* new unused entry */
 849	xfs_dir2_data_unused_t	*postdup;	/* unused entry after us */
 850	xfs_dir2_data_unused_t	*prevdup;	/* unused entry before us */
 851	unsigned int		end;
 852	struct xfs_dir2_data_free *bf;
 853
 854	hdr = bp->b_addr;
 855
 856	/*
 857	 * Figure out where the end of the data area is.
 858	 */
 859	end = xfs_dir3_data_end_offset(args->geo, hdr);
 860	ASSERT(end != 0);
 861
 862	/*
 863	 * If this isn't the start of the block, then back up to
 864	 * the previous entry and see if it's free.
 865	 */
 866	if (offset > args->geo->data_entry_offset) {
 867		__be16			*tagp;	/* tag just before us */
 868
 869		tagp = (__be16 *)((char *)hdr + offset) - 1;
 870		prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
 871		if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
 872			prevdup = NULL;
 873	} else
 874		prevdup = NULL;
 875	/*
 876	 * If this isn't the end of the block, see if the entry after
 877	 * us is free.
 878	 */
 879	if (offset + len < end) {
 880		postdup =
 881			(xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
 882		if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
 883			postdup = NULL;
 884	} else
 885		postdup = NULL;
 886	ASSERT(*needscanp == 0);
 887	needscan = 0;
 888	/*
 889	 * Previous and following entries are both free,
 890	 * merge everything into a single free entry.
 891	 */
 892	bf = xfs_dir2_data_bestfree_p(args->dp->i_mount, hdr);
 893	if (prevdup && postdup) {
 894		xfs_dir2_data_free_t	*dfp2;	/* another bestfree pointer */
 895
 896		/*
 897		 * See if prevdup and/or postdup are in bestfree table.
 898		 */
 899		dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
 900		dfp2 = xfs_dir2_data_freefind(hdr, bf, postdup);
 901		/*
 902		 * We need a rescan unless there are exactly 2 free entries
 903		 * namely our two.  Then we know what's happening, otherwise
 904		 * since the third bestfree is there, there might be more
 905		 * entries.
 906		 */
 907		needscan = (bf[2].length != 0);
 908		/*
 909		 * Fix up the new big freespace.
 910		 */
 911		be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
 912		*xfs_dir2_data_unused_tag_p(prevdup) =
 913			cpu_to_be16((char *)prevdup - (char *)hdr);
 914		xfs_dir2_data_log_unused(args, bp, prevdup);
 915		if (!needscan) {
 916			/*
 917			 * Has to be the case that entries 0 and 1 are
 918			 * dfp and dfp2 (don't know which is which), and
 919			 * entry 2 is empty.
 920			 * Remove entry 1 first then entry 0.
 921			 */
 922			ASSERT(dfp && dfp2);
 923			if (dfp == &bf[1]) {
 924				dfp = &bf[0];
 925				ASSERT(dfp2 == dfp);
 926				dfp2 = &bf[1];
 927			}
 928			xfs_dir2_data_freeremove(hdr, bf, dfp2, needlogp);
 929			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
 930			/*
 931			 * Now insert the new entry.
 932			 */
 933			dfp = xfs_dir2_data_freeinsert(hdr, bf, prevdup,
 934						       needlogp);
 935			ASSERT(dfp == &bf[0]);
 936			ASSERT(dfp->length == prevdup->length);
 937			ASSERT(!dfp[1].length);
 938			ASSERT(!dfp[2].length);
 939		}
 940	}
 941	/*
 942	 * The entry before us is free, merge with it.
 943	 */
 944	else if (prevdup) {
 945		dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
 946		be16_add_cpu(&prevdup->length, len);
 947		*xfs_dir2_data_unused_tag_p(prevdup) =
 948			cpu_to_be16((char *)prevdup - (char *)hdr);
 949		xfs_dir2_data_log_unused(args, bp, prevdup);
 950		/*
 951		 * If the previous entry was in the table, the new entry
 952		 * is longer, so it will be in the table too.  Remove
 953		 * the old one and add the new one.
 954		 */
 955		if (dfp) {
 956			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
 957			xfs_dir2_data_freeinsert(hdr, bf, prevdup, needlogp);
 958		}
 959		/*
 960		 * Otherwise we need a scan if the new entry is big enough.
 961		 */
 962		else {
 963			needscan = be16_to_cpu(prevdup->length) >
 964				   be16_to_cpu(bf[2].length);
 965		}
 966	}
 967	/*
 968	 * The following entry is free, merge with it.
 969	 */
 970	else if (postdup) {
 971		dfp = xfs_dir2_data_freefind(hdr, bf, postdup);
 972		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
 973		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
 974		newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
 975		*xfs_dir2_data_unused_tag_p(newdup) =
 976			cpu_to_be16((char *)newdup - (char *)hdr);
 977		xfs_dir2_data_log_unused(args, bp, newdup);
 978		/*
 979		 * If the following entry was in the table, the new entry
 980		 * is longer, so it will be in the table too.  Remove
 981		 * the old one and add the new one.
 982		 */
 983		if (dfp) {
 984			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
 985			xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
 986		}
 987		/*
 988		 * Otherwise we need a scan if the new entry is big enough.
 989		 */
 990		else {
 991			needscan = be16_to_cpu(newdup->length) >
 992				   be16_to_cpu(bf[2].length);
 993		}
 994	}
 995	/*
 996	 * Neither neighbor is free.  Make a new entry.
 997	 */
 998	else {
 999		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
1000		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1001		newdup->length = cpu_to_be16(len);
1002		*xfs_dir2_data_unused_tag_p(newdup) =
1003			cpu_to_be16((char *)newdup - (char *)hdr);
1004		xfs_dir2_data_log_unused(args, bp, newdup);
1005		xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
1006	}
1007	*needscanp = needscan;
1008}
1009
1010/* Check our free data for obvious signs of corruption. */
1011static inline xfs_failaddr_t
1012xfs_dir2_data_check_free(
1013	struct xfs_dir2_data_hdr	*hdr,
1014	struct xfs_dir2_data_unused	*dup,
1015	xfs_dir2_data_aoff_t		offset,
1016	xfs_dir2_data_aoff_t		len)
1017{
1018	if (hdr->magic != cpu_to_be32(XFS_DIR2_DATA_MAGIC) &&
1019	    hdr->magic != cpu_to_be32(XFS_DIR3_DATA_MAGIC) &&
1020	    hdr->magic != cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) &&
1021	    hdr->magic != cpu_to_be32(XFS_DIR3_BLOCK_MAGIC))
1022		return __this_address;
1023	if (be16_to_cpu(dup->freetag) != XFS_DIR2_DATA_FREE_TAG)
1024		return __this_address;
1025	if (offset < (char *)dup - (char *)hdr)
1026		return __this_address;
1027	if (offset + len > (char *)dup + be16_to_cpu(dup->length) - (char *)hdr)
1028		return __this_address;
1029	if ((char *)dup - (char *)hdr !=
1030			be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)))
1031		return __this_address;
1032	return NULL;
1033}
1034
1035/* Sanity-check a new bestfree entry. */
1036static inline xfs_failaddr_t
1037xfs_dir2_data_check_new_free(
1038	struct xfs_dir2_data_hdr	*hdr,
1039	struct xfs_dir2_data_free	*dfp,
1040	struct xfs_dir2_data_unused	*newdup)
1041{
1042	if (dfp == NULL)
1043		return __this_address;
1044	if (dfp->length != newdup->length)
1045		return __this_address;
1046	if (be16_to_cpu(dfp->offset) != (char *)newdup - (char *)hdr)
1047		return __this_address;
1048	return NULL;
1049}
1050
1051/*
1052 * Take a byte range out of an existing unused space and make it un-free.
1053 */
1054int
1055xfs_dir2_data_use_free(
1056	struct xfs_da_args	*args,
1057	struct xfs_buf		*bp,
1058	xfs_dir2_data_unused_t	*dup,		/* unused entry */
1059	xfs_dir2_data_aoff_t	offset,		/* starting offset to use */
1060	xfs_dir2_data_aoff_t	len,		/* length to use */
1061	int			*needlogp,	/* out: need to log header */
1062	int			*needscanp)	/* out: need regen bestfree */
1063{
1064	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
1065	xfs_dir2_data_free_t	*dfp;		/* bestfree pointer */
1066	xfs_dir2_data_unused_t	*newdup;	/* new unused entry */
1067	xfs_dir2_data_unused_t	*newdup2;	/* another new unused entry */
1068	struct xfs_dir2_data_free *bf;
1069	xfs_failaddr_t		fa;
1070	int			matchback;	/* matches end of freespace */
1071	int			matchfront;	/* matches start of freespace */
1072	int			needscan;	/* need to regen bestfree */
1073	int			oldlen;		/* old unused entry's length */
1074
1075	hdr = bp->b_addr;
1076	fa = xfs_dir2_data_check_free(hdr, dup, offset, len);
1077	if (fa)
1078		goto corrupt;
1079	/*
1080	 * Look up the entry in the bestfree table.
1081	 */
1082	oldlen = be16_to_cpu(dup->length);
1083	bf = xfs_dir2_data_bestfree_p(args->dp->i_mount, hdr);
1084	dfp = xfs_dir2_data_freefind(hdr, bf, dup);
1085	ASSERT(dfp || oldlen <= be16_to_cpu(bf[2].length));
1086	/*
1087	 * Check for alignment with front and back of the entry.
1088	 */
1089	matchfront = (char *)dup - (char *)hdr == offset;
1090	matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
1091	ASSERT(*needscanp == 0);
1092	needscan = 0;
1093	/*
1094	 * If we matched it exactly we just need to get rid of it from
1095	 * the bestfree table.
1096	 */
1097	if (matchfront && matchback) {
1098		if (dfp) {
1099			needscan = (bf[2].offset != 0);
1100			if (!needscan)
1101				xfs_dir2_data_freeremove(hdr, bf, dfp,
1102							 needlogp);
1103		}
1104	}
1105	/*
1106	 * We match the first part of the entry.
1107	 * Make a new entry with the remaining freespace.
1108	 */
1109	else if (matchfront) {
1110		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
1111		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1112		newdup->length = cpu_to_be16(oldlen - len);
1113		*xfs_dir2_data_unused_tag_p(newdup) =
1114			cpu_to_be16((char *)newdup - (char *)hdr);
1115		xfs_dir2_data_log_unused(args, bp, newdup);
1116		/*
1117		 * If it was in the table, remove it and add the new one.
1118		 */
1119		if (dfp) {
1120			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
1121			dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
1122						       needlogp);
1123			fa = xfs_dir2_data_check_new_free(hdr, dfp, newdup);
1124			if (fa)
1125				goto corrupt;
1126			/*
1127			 * If we got inserted at the last slot,
1128			 * that means we don't know if there was a better
1129			 * choice for the last slot, or not.  Rescan.
1130			 */
1131			needscan = dfp == &bf[2];
1132		}
1133	}
1134	/*
1135	 * We match the last part of the entry.
1136	 * Trim the allocated space off the tail of the entry.
1137	 */
1138	else if (matchback) {
1139		newdup = dup;
1140		newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
1141		*xfs_dir2_data_unused_tag_p(newdup) =
1142			cpu_to_be16((char *)newdup - (char *)hdr);
1143		xfs_dir2_data_log_unused(args, bp, newdup);
1144		/*
1145		 * If it was in the table, remove it and add the new one.
1146		 */
1147		if (dfp) {
1148			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
1149			dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
1150						       needlogp);
1151			fa = xfs_dir2_data_check_new_free(hdr, dfp, newdup);
1152			if (fa)
1153				goto corrupt;
1154			/*
1155			 * If we got inserted at the last slot,
1156			 * that means we don't know if there was a better
1157			 * choice for the last slot, or not.  Rescan.
1158			 */
1159			needscan = dfp == &bf[2];
1160		}
1161	}
1162	/*
1163	 * Poking out the middle of an entry.
1164	 * Make two new entries.
1165	 */
1166	else {
1167		newdup = dup;
1168		newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
1169		*xfs_dir2_data_unused_tag_p(newdup) =
1170			cpu_to_be16((char *)newdup - (char *)hdr);
1171		xfs_dir2_data_log_unused(args, bp, newdup);
1172		newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
1173		newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1174		newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
1175		*xfs_dir2_data_unused_tag_p(newdup2) =
1176			cpu_to_be16((char *)newdup2 - (char *)hdr);
1177		xfs_dir2_data_log_unused(args, bp, newdup2);
1178		/*
1179		 * If the old entry was in the table, we need to scan
1180		 * if the 3rd entry was valid, since these entries
1181		 * are smaller than the old one.
1182		 * If we don't need to scan that means there were 1 or 2
1183		 * entries in the table, and removing the old and adding
1184		 * the 2 new will work.
1185		 */
1186		if (dfp) {
1187			needscan = (bf[2].length != 0);
1188			if (!needscan) {
1189				xfs_dir2_data_freeremove(hdr, bf, dfp,
1190							 needlogp);
1191				xfs_dir2_data_freeinsert(hdr, bf, newdup,
1192							 needlogp);
1193				xfs_dir2_data_freeinsert(hdr, bf, newdup2,
1194							 needlogp);
1195			}
1196		}
1197	}
1198	*needscanp = needscan;
1199	return 0;
1200corrupt:
1201	xfs_corruption_error(__func__, XFS_ERRLEVEL_LOW, args->dp->i_mount,
1202			hdr, sizeof(*hdr), __FILE__, __LINE__, fa);
1203	xfs_da_mark_sick(args);
1204	return -EFSCORRUPTED;
1205}
1206
1207/* Find the end of the entry data in a data/block format dir block. */
1208unsigned int
1209xfs_dir3_data_end_offset(
1210	struct xfs_da_geometry		*geo,
1211	struct xfs_dir2_data_hdr	*hdr)
1212{
1213	void				*p;
1214
1215	switch (hdr->magic) {
1216	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
1217	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
1218		p = xfs_dir2_block_leaf_p(xfs_dir2_block_tail_p(geo, hdr));
1219		return p - (void *)hdr;
1220	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
1221	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
1222		return geo->blksize;
1223	default:
1224		return 0;
1225	}
1226}