1/*
   2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#include "xfs.h"
  19#include "xfs_fs.h"
  20#include "xfs_types.h"
  21#include "xfs_bit.h"
  22#include "xfs_log.h"
  23#include "xfs_inum.h"
  24#include "xfs_trans.h"
  25#include "xfs_sb.h"
  26#include "xfs_ag.h"
  27#include "xfs_dir2.h"
  28#include "xfs_mount.h"
  29#include "xfs_bmap_btree.h"
  30#include "xfs_dinode.h"
  31#include "xfs_inode.h"
  32#include "xfs_alloc.h"
  33#include "xfs_bmap.h"
  34#include "xfs_rtalloc.h"
  35#include "xfs_fsops.h"
  36#include "xfs_error.h"
  37#include "xfs_rw.h"
  38#include "xfs_inode_item.h"
  39#include "xfs_trans_space.h"
  40#include "xfs_utils.h"
  41#include "xfs_trace.h"
  42#include "xfs_buf.h"
  43
  44
  45/*
  46 * Prototypes for internal functions.
  47 */
  48
  49
  50STATIC int xfs_rtallocate_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  51		xfs_extlen_t, xfs_buf_t **, xfs_fsblock_t *);
  52STATIC int xfs_rtany_summary(xfs_mount_t *, xfs_trans_t *, int, int,
  53		xfs_rtblock_t, xfs_buf_t **, xfs_fsblock_t *, int *);
  54STATIC int xfs_rtcheck_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  55		xfs_extlen_t, int, xfs_rtblock_t *, int *);
  56STATIC int xfs_rtfind_back(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  57		xfs_rtblock_t, xfs_rtblock_t *);
  58STATIC int xfs_rtfind_forw(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  59		xfs_rtblock_t, xfs_rtblock_t *);
  60STATIC int xfs_rtget_summary( xfs_mount_t *, xfs_trans_t *, int,
  61		xfs_rtblock_t, xfs_buf_t **, xfs_fsblock_t *, xfs_suminfo_t *);
  62STATIC int xfs_rtmodify_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  63		xfs_extlen_t, int);
  64STATIC int xfs_rtmodify_summary(xfs_mount_t *, xfs_trans_t *, int,
  65		xfs_rtblock_t, int, xfs_buf_t **, xfs_fsblock_t *);
  66
  67/*
  68 * Internal functions.
  69 */
  70
  71/*
  72 * Allocate space to the bitmap or summary file, and zero it, for growfs.
  73 */
  74STATIC int				/* error */
  75xfs_growfs_rt_alloc(
  76	xfs_mount_t	*mp,		/* file system mount point */
  77	xfs_extlen_t	oblocks,	/* old count of blocks */
  78	xfs_extlen_t	nblocks,	/* new count of blocks */
  79	xfs_inode_t	*ip)		/* inode (bitmap/summary) */
  80{
  81	xfs_fileoff_t	bno;		/* block number in file */
  82	xfs_buf_t	*bp;		/* temporary buffer for zeroing */
  83	int		committed;	/* transaction committed flag */
  84	xfs_daddr_t	d;		/* disk block address */
  85	int		error;		/* error return value */
  86	xfs_fsblock_t	firstblock;	/* first block allocated in xaction */
  87	xfs_bmap_free_t	flist;		/* list of freed blocks */
  88	xfs_fsblock_t	fsbno;		/* filesystem block for bno */
  89	xfs_bmbt_irec_t	map;		/* block map output */
  90	int		nmap;		/* number of block maps */
  91	int		resblks;	/* space reservation */
  92
  93	/*
  94	 * Allocate space to the file, as necessary.
  95	 */
  96	while (oblocks < nblocks) {
  97		int		cancelflags = 0;
  98		xfs_trans_t	*tp;
  99
 100		tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_ALLOC);
 101		resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
 102		/*
 103		 * Reserve space & log for one extent added to the file.
 104		 */
 105		if ((error = xfs_trans_reserve(tp, resblks,
 106				XFS_GROWRTALLOC_LOG_RES(mp), 0,
 107				XFS_TRANS_PERM_LOG_RES,
 108				XFS_DEFAULT_PERM_LOG_COUNT)))
 109			goto error_cancel;
 110		cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 111		/*
 112		 * Lock the inode.
 113		 */
 114		xfs_ilock(ip, XFS_ILOCK_EXCL);
 115		xfs_trans_ijoin_ref(tp, ip, XFS_ILOCK_EXCL);
 116
 117		xfs_bmap_init(&flist, &firstblock);
 118		/*
 119		 * Allocate blocks to the bitmap file.
 120		 */
 121		nmap = 1;
 122		cancelflags |= XFS_TRANS_ABORT;
 123		error = xfs_bmapi(tp, ip, oblocks, nblocks - oblocks,
 124			XFS_BMAPI_WRITE | XFS_BMAPI_METADATA, &firstblock,
 125			resblks, &map, &nmap, &flist);
 126		if (!error && nmap < 1)
 127			error = XFS_ERROR(ENOSPC);
 128		if (error)
 129			goto error_cancel;
 130		/*
 131		 * Free any blocks freed up in the transaction, then commit.
 132		 */
 133		error = xfs_bmap_finish(&tp, &flist, &committed);
 134		if (error)
 135			goto error_cancel;
 136		error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 137		if (error)
 138			goto error;
 139		/*
 140		 * Now we need to clear the allocated blocks.
 141		 * Do this one block per transaction, to keep it simple.
 142		 */
 143		cancelflags = 0;
 144		for (bno = map.br_startoff, fsbno = map.br_startblock;
 145		     bno < map.br_startoff + map.br_blockcount;
 146		     bno++, fsbno++) {
 147			tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_ZERO);
 148			/*
 149			 * Reserve log for one block zeroing.
 150			 */
 151			if ((error = xfs_trans_reserve(tp, 0,
 152					XFS_GROWRTZERO_LOG_RES(mp), 0, 0, 0)))
 153				goto error_cancel;
 154			/*
 155			 * Lock the bitmap inode.
 156			 */
 157			xfs_ilock(ip, XFS_ILOCK_EXCL);
 158			xfs_trans_ijoin_ref(tp, ip, XFS_ILOCK_EXCL);
 159			/*
 160			 * Get a buffer for the block.
 161			 */
 162			d = XFS_FSB_TO_DADDR(mp, fsbno);
 163			bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
 164				mp->m_bsize, 0);
 165			if (bp == NULL) {
 166				error = XFS_ERROR(EIO);
 167error_cancel:
 168				xfs_trans_cancel(tp, cancelflags);
 169				goto error;
 170			}
 171			memset(bp->b_addr, 0, mp->m_sb.sb_blocksize);
 172			xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
 173			/*
 174			 * Commit the transaction.
 175			 */
 176			error = xfs_trans_commit(tp, 0);
 177			if (error)
 178				goto error;
 179		}
 180		/*
 181		 * Go on to the next extent, if any.
 182		 */
 183		oblocks = map.br_startoff + map.br_blockcount;
 184	}
 185	return 0;
 
 186error:
 187	return error;
 188}
 189
 190/*
 191 * Attempt to allocate an extent minlen<=len<=maxlen starting from
 192 * bitmap block bbno.  If we don't get maxlen then use prod to trim
 193 * the length, if given.  Returns error; returns starting block in *rtblock.
 194 * The lengths are all in rtextents.
 195 */
 196STATIC int				/* error */
 197xfs_rtallocate_extent_block(
 198	xfs_mount_t	*mp,		/* file system mount point */
 199	xfs_trans_t	*tp,		/* transaction pointer */
 200	xfs_rtblock_t	bbno,		/* bitmap block number */
 201	xfs_extlen_t	minlen,		/* minimum length to allocate */
 202	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 203	xfs_extlen_t	*len,		/* out: actual length allocated */
 204	xfs_rtblock_t	*nextp,		/* out: next block to try */
 205	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
 206	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 207	xfs_extlen_t	prod,		/* extent product factor */
 208	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 209{
 210	xfs_rtblock_t	besti;		/* best rtblock found so far */
 211	xfs_rtblock_t	bestlen;	/* best length found so far */
 212	xfs_rtblock_t	end;		/* last rtblock in chunk */
 213	int		error;		/* error value */
 214	xfs_rtblock_t	i;		/* current rtblock trying */
 215	xfs_rtblock_t	next;		/* next rtblock to try */
 216	int		stat;		/* status from internal calls */
 217
 218	/*
 219	 * Loop over all the extents starting in this bitmap block,
 220	 * looking for one that's long enough.
 221	 */
 222	for (i = XFS_BLOCKTOBIT(mp, bbno), besti = -1, bestlen = 0,
 223		end = XFS_BLOCKTOBIT(mp, bbno + 1) - 1;
 224	     i <= end;
 225	     i++) {
 226		/*
 227		 * See if there's a free extent of maxlen starting at i.
 228		 * If it's not so then next will contain the first non-free.
 229		 */
 230		error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, &next, &stat);
 231		if (error) {
 232			return error;
 233		}
 234		if (stat) {
 235			/*
 236			 * i for maxlen is all free, allocate and return that.
 237			 */
 238			error = xfs_rtallocate_range(mp, tp, i, maxlen, rbpp,
 239				rsb);
 240			if (error) {
 241				return error;
 242			}
 243			*len = maxlen;
 244			*rtblock = i;
 245			return 0;
 246		}
 247		/*
 248		 * In the case where we have a variable-sized allocation
 249		 * request, figure out how big this free piece is,
 250		 * and if it's big enough for the minimum, and the best
 251		 * so far, remember it.
 252		 */
 253		if (minlen < maxlen) {
 254			xfs_rtblock_t	thislen;	/* this extent size */
 255
 256			thislen = next - i;
 257			if (thislen >= minlen && thislen > bestlen) {
 258				besti = i;
 259				bestlen = thislen;
 260			}
 261		}
 262		/*
 263		 * If not done yet, find the start of the next free space.
 264		 */
 265		if (next < end) {
 266			error = xfs_rtfind_forw(mp, tp, next, end, &i);
 267			if (error) {
 268				return error;
 269			}
 270		} else
 271			break;
 272	}
 273	/*
 274	 * Searched the whole thing & didn't find a maxlen free extent.
 275	 */
 276	if (minlen < maxlen && besti != -1) {
 277		xfs_extlen_t	p;	/* amount to trim length by */
 278
 279		/*
 280		 * If size should be a multiple of prod, make that so.
 281		 */
 282		if (prod > 1 && (p = do_mod(bestlen, prod)))
 283			bestlen -= p;
 284		/*
 285		 * Allocate besti for bestlen & return that.
 286		 */
 287		error = xfs_rtallocate_range(mp, tp, besti, bestlen, rbpp, rsb);
 288		if (error) {
 289			return error;
 290		}
 291		*len = bestlen;
 292		*rtblock = besti;
 293		return 0;
 294	}
 295	/*
 296	 * Allocation failed.  Set *nextp to the next block to try.
 297	 */
 298	*nextp = next;
 299	*rtblock = NULLRTBLOCK;
 300	return 0;
 301}
 302
 303/*
 304 * Allocate an extent of length minlen<=len<=maxlen, starting at block
 305 * bno.  If we don't get maxlen then use prod to trim the length, if given.
 306 * Returns error; returns starting block in *rtblock.
 307 * The lengths are all in rtextents.
 308 */
 309STATIC int				/* error */
 310xfs_rtallocate_extent_exact(
 311	xfs_mount_t	*mp,		/* file system mount point */
 312	xfs_trans_t	*tp,		/* transaction pointer */
 313	xfs_rtblock_t	bno,		/* starting block number to allocate */
 314	xfs_extlen_t	minlen,		/* minimum length to allocate */
 315	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 316	xfs_extlen_t	*len,		/* out: actual length allocated */
 317	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
 318	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 319	xfs_extlen_t	prod,		/* extent product factor */
 320	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 321{
 322	int		error;		/* error value */
 323	xfs_extlen_t	i;		/* extent length trimmed due to prod */
 324	int		isfree;		/* extent is free */
 325	xfs_rtblock_t	next;		/* next block to try (dummy) */
 326
 327	ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 328	/*
 329	 * Check if the range in question (for maxlen) is free.
 330	 */
 331	error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, &next, &isfree);
 332	if (error) {
 333		return error;
 334	}
 335	if (isfree) {
 336		/*
 337		 * If it is, allocate it and return success.
 338		 */
 339		error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
 340		if (error) {
 341			return error;
 342		}
 343		*len = maxlen;
 344		*rtblock = bno;
 345		return 0;
 346	}
 347	/*
 348	 * If not, allocate what there is, if it's at least minlen.
 349	 */
 350	maxlen = next - bno;
 351	if (maxlen < minlen) {
 352		/*
 353		 * Failed, return failure status.
 354		 */
 355		*rtblock = NULLRTBLOCK;
 356		return 0;
 357	}
 358	/*
 359	 * Trim off tail of extent, if prod is specified.
 360	 */
 361	if (prod > 1 && (i = maxlen % prod)) {
 362		maxlen -= i;
 363		if (maxlen < minlen) {
 364			/*
 365			 * Now we can't do it, return failure status.
 366			 */
 367			*rtblock = NULLRTBLOCK;
 368			return 0;
 369		}
 370	}
 371	/*
 372	 * Allocate what we can and return it.
 373	 */
 374	error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
 375	if (error) {
 376		return error;
 377	}
 378	*len = maxlen;
 379	*rtblock = bno;
 380	return 0;
 381}
 382
 383/*
 384 * Allocate an extent of length minlen<=len<=maxlen, starting as near
 385 * to bno as possible.  If we don't get maxlen then use prod to trim
 386 * the length, if given.  The lengths are all in rtextents.
 387 */
 388STATIC int				/* error */
 389xfs_rtallocate_extent_near(
 390	xfs_mount_t	*mp,		/* file system mount point */
 391	xfs_trans_t	*tp,		/* transaction pointer */
 392	xfs_rtblock_t	bno,		/* starting block number to allocate */
 393	xfs_extlen_t	minlen,		/* minimum length to allocate */
 394	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 395	xfs_extlen_t	*len,		/* out: actual length allocated */
 396	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
 397	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 398	xfs_extlen_t	prod,		/* extent product factor */
 399	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 400{
 401	int		any;		/* any useful extents from summary */
 402	xfs_rtblock_t	bbno;		/* bitmap block number */
 403	int		error;		/* error value */
 404	int		i;		/* bitmap block offset (loop control) */
 405	int		j;		/* secondary loop control */
 406	int		log2len;	/* log2 of minlen */
 407	xfs_rtblock_t	n;		/* next block to try */
 408	xfs_rtblock_t	r;		/* result block */
 409
 410	ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 411	/*
 412	 * If the block number given is off the end, silently set it to
 413	 * the last block.
 414	 */
 415	if (bno >= mp->m_sb.sb_rextents)
 416		bno = mp->m_sb.sb_rextents - 1;
 417	/*
 418	 * Try the exact allocation first.
 419	 */
 420	error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
 421		rbpp, rsb, prod, &r);
 422	if (error) {
 423		return error;
 424	}
 425	/*
 426	 * If the exact allocation worked, return that.
 427	 */
 428	if (r != NULLRTBLOCK) {
 429		*rtblock = r;
 430		return 0;
 431	}
 432	bbno = XFS_BITTOBLOCK(mp, bno);
 433	i = 0;
 434	ASSERT(minlen != 0);
 435	log2len = xfs_highbit32(minlen);
 436	/*
 437	 * Loop over all bitmap blocks (bbno + i is current block).
 438	 */
 439	for (;;) {
 440		/*
 441		 * Get summary information of extents of all useful levels
 442		 * starting in this bitmap block.
 443		 */
 444		error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
 445			bbno + i, rbpp, rsb, &any);
 446		if (error) {
 447			return error;
 448		}
 449		/*
 450		 * If there are any useful extents starting here, try
 451		 * allocating one.
 452		 */
 453		if (any) {
 454			/*
 455			 * On the positive side of the starting location.
 456			 */
 457			if (i >= 0) {
 458				/*
 459				 * Try to allocate an extent starting in
 460				 * this block.
 461				 */
 462				error = xfs_rtallocate_extent_block(mp, tp,
 463					bbno + i, minlen, maxlen, len, &n, rbpp,
 464					rsb, prod, &r);
 465				if (error) {
 466					return error;
 467				}
 468				/*
 469				 * If it worked, return it.
 470				 */
 471				if (r != NULLRTBLOCK) {
 472					*rtblock = r;
 473					return 0;
 474				}
 475			}
 476			/*
 477			 * On the negative side of the starting location.
 478			 */
 479			else {		/* i < 0 */
 480				/*
 481				 * Loop backwards through the bitmap blocks from
 482				 * the starting point-1 up to where we are now.
 483				 * There should be an extent which ends in this
 484				 * bitmap block and is long enough.
 485				 */
 486				for (j = -1; j > i; j--) {
 487					/*
 488					 * Grab the summary information for
 489					 * this bitmap block.
 490					 */
 491					error = xfs_rtany_summary(mp, tp,
 492						log2len, mp->m_rsumlevels - 1,
 493						bbno + j, rbpp, rsb, &any);
 494					if (error) {
 495						return error;
 496					}
 497					/*
 498					 * If there's no extent given in the
 499					 * summary that means the extent we
 500					 * found must carry over from an
 501					 * earlier block.  If there is an
 502					 * extent given, we've already tried
 503					 * that allocation, don't do it again.
 504					 */
 505					if (any)
 506						continue;
 507					error = xfs_rtallocate_extent_block(mp,
 508						tp, bbno + j, minlen, maxlen,
 509						len, &n, rbpp, rsb, prod, &r);
 510					if (error) {
 511						return error;
 512					}
 513					/*
 514					 * If it works, return the extent.
 515					 */
 516					if (r != NULLRTBLOCK) {
 517						*rtblock = r;
 518						return 0;
 519					}
 520				}
 521				/*
 522				 * There weren't intervening bitmap blocks
 523				 * with a long enough extent, or the
 524				 * allocation didn't work for some reason
 525				 * (i.e. it's a little * too short).
 526				 * Try to allocate from the summary block
 527				 * that we found.
 528				 */
 529				error = xfs_rtallocate_extent_block(mp, tp,
 530					bbno + i, minlen, maxlen, len, &n, rbpp,
 531					rsb, prod, &r);
 532				if (error) {
 533					return error;
 534				}
 535				/*
 536				 * If it works, return the extent.
 537				 */
 538				if (r != NULLRTBLOCK) {
 539					*rtblock = r;
 540					return 0;
 541				}
 542			}
 543		}
 544		/*
 545		 * Loop control.  If we were on the positive side, and there's
 546		 * still more blocks on the negative side, go there.
 547		 */
 548		if (i > 0 && (int)bbno - i >= 0)
 549			i = -i;
 550		/*
 551		 * If positive, and no more negative, but there are more
 552		 * positive, go there.
 553		 */
 554		else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
 555			i++;
 556		/*
 557		 * If negative or 0 (just started), and there are positive
 558		 * blocks to go, go there.  The 0 case moves to block 1.
 559		 */
 560		else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
 561			i = 1 - i;
 562		/*
 563		 * If negative or 0 and there are more negative blocks,
 564		 * go there.
 565		 */
 566		else if (i <= 0 && (int)bbno + i > 0)
 567			i--;
 568		/*
 569		 * Must be done.  Return failure.
 570		 */
 571		else
 572			break;
 573	}
 574	*rtblock = NULLRTBLOCK;
 575	return 0;
 576}
 577
 578/*
 579 * Allocate an extent of length minlen<=len<=maxlen, with no position
 580 * specified.  If we don't get maxlen then use prod to trim
 581 * the length, if given.  The lengths are all in rtextents.
 582 */
 583STATIC int				/* error */
 584xfs_rtallocate_extent_size(
 585	xfs_mount_t	*mp,		/* file system mount point */
 586	xfs_trans_t	*tp,		/* transaction pointer */
 587	xfs_extlen_t	minlen,		/* minimum length to allocate */
 588	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 589	xfs_extlen_t	*len,		/* out: actual length allocated */
 590	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
 591	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 592	xfs_extlen_t	prod,		/* extent product factor */
 593	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 594{
 595	int		error;		/* error value */
 596	int		i;		/* bitmap block number */
 597	int		l;		/* level number (loop control) */
 598	xfs_rtblock_t	n;		/* next block to be tried */
 599	xfs_rtblock_t	r;		/* result block number */
 600	xfs_suminfo_t	sum;		/* summary information for extents */
 601
 602	ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 603	ASSERT(maxlen != 0);
 604
 605	/*
 606	 * Loop over all the levels starting with maxlen.
 607	 * At each level, look at all the bitmap blocks, to see if there
 608	 * are extents starting there that are long enough (>= maxlen).
 609	 * Note, only on the initial level can the allocation fail if
 610	 * the summary says there's an extent.
 611	 */
 612	for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) {
 613		/*
 614		 * Loop over all the bitmap blocks.
 615		 */
 616		for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
 617			/*
 618			 * Get the summary for this level/block.
 619			 */
 620			error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
 621				&sum);
 622			if (error) {
 623				return error;
 624			}
 625			/*
 626			 * Nothing there, on to the next block.
 627			 */
 628			if (!sum)
 629				continue;
 630			/*
 631			 * Try allocating the extent.
 632			 */
 633			error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
 634				maxlen, len, &n, rbpp, rsb, prod, &r);
 635			if (error) {
 636				return error;
 637			}
 638			/*
 639			 * If it worked, return that.
 640			 */
 641			if (r != NULLRTBLOCK) {
 642				*rtblock = r;
 643				return 0;
 644			}
 645			/*
 646			 * If the "next block to try" returned from the
 647			 * allocator is beyond the next bitmap block,
 648			 * skip to that bitmap block.
 649			 */
 650			if (XFS_BITTOBLOCK(mp, n) > i + 1)
 651				i = XFS_BITTOBLOCK(mp, n) - 1;
 652		}
 653	}
 654	/*
 655	 * Didn't find any maxlen blocks.  Try smaller ones, unless
 656	 * we're asking for a fixed size extent.
 657	 */
 658	if (minlen > --maxlen) {
 659		*rtblock = NULLRTBLOCK;
 660		return 0;
 661	}
 662	ASSERT(minlen != 0);
 663	ASSERT(maxlen != 0);
 664
 665	/*
 666	 * Loop over sizes, from maxlen down to minlen.
 667	 * This time, when we do the allocations, allow smaller ones
 668	 * to succeed.
 669	 */
 670	for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
 671		/*
 672		 * Loop over all the bitmap blocks, try an allocation
 673		 * starting in that block.
 674		 */
 675		for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
 676			/*
 677			 * Get the summary information for this level/block.
 678			 */
 679			error =	xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
 680						  &sum);
 681			if (error) {
 682				return error;
 683			}
 684			/*
 685			 * If nothing there, go on to next.
 686			 */
 687			if (!sum)
 688				continue;
 689			/*
 690			 * Try the allocation.  Make sure the specified
 691			 * minlen/maxlen are in the possible range for
 692			 * this summary level.
 693			 */
 694			error = xfs_rtallocate_extent_block(mp, tp, i,
 695					XFS_RTMAX(minlen, 1 << l),
 696					XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
 697					len, &n, rbpp, rsb, prod, &r);
 698			if (error) {
 699				return error;
 700			}
 701			/*
 702			 * If it worked, return that extent.
 703			 */
 704			if (r != NULLRTBLOCK) {
 705				*rtblock = r;
 706				return 0;
 707			}
 708			/*
 709			 * If the "next block to try" returned from the
 710			 * allocator is beyond the next bitmap block,
 711			 * skip to that bitmap block.
 712			 */
 713			if (XFS_BITTOBLOCK(mp, n) > i + 1)
 714				i = XFS_BITTOBLOCK(mp, n) - 1;
 715		}
 716	}
 717	/*
 718	 * Got nothing, return failure.
 719	 */
 720	*rtblock = NULLRTBLOCK;
 721	return 0;
 722}
 723
 724/*
 725 * Mark an extent specified by start and len allocated.
 726 * Updates all the summary information as well as the bitmap.
 727 */
 728STATIC int				/* error */
 729xfs_rtallocate_range(
 730	xfs_mount_t	*mp,		/* file system mount point */
 731	xfs_trans_t	*tp,		/* transaction pointer */
 732	xfs_rtblock_t	start,		/* start block to allocate */
 733	xfs_extlen_t	len,		/* length to allocate */
 734	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
 735	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
 736{
 737	xfs_rtblock_t	end;		/* end of the allocated extent */
 738	int		error;		/* error value */
 739	xfs_rtblock_t	postblock;	/* first block allocated > end */
 740	xfs_rtblock_t	preblock;	/* first block allocated < start */
 741
 742	end = start + len - 1;
 743	/*
 744	 * Assume we're allocating out of the middle of a free extent.
 745	 * We need to find the beginning and end of the extent so we can
 746	 * properly update the summary.
 747	 */
 748	error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
 749	if (error) {
 750		return error;
 751	}
 752	/*
 753	 * Find the next allocated block (end of free extent).
 754	 */
 755	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
 756		&postblock);
 757	if (error) {
 758		return error;
 759	}
 760	/*
 761	 * Decrement the summary information corresponding to the entire
 762	 * (old) free extent.
 763	 */
 764	error = xfs_rtmodify_summary(mp, tp,
 765		XFS_RTBLOCKLOG(postblock + 1 - preblock),
 766		XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
 767	if (error) {
 768		return error;
 769	}
 770	/*
 771	 * If there are blocks not being allocated at the front of the
 772	 * old extent, add summary data for them to be free.
 773	 */
 774	if (preblock < start) {
 775		error = xfs_rtmodify_summary(mp, tp,
 776			XFS_RTBLOCKLOG(start - preblock),
 777			XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
 778		if (error) {
 779			return error;
 780		}
 781	}
 782	/*
 783	 * If there are blocks not being allocated at the end of the
 784	 * old extent, add summary data for them to be free.
 785	 */
 786	if (postblock > end) {
 787		error = xfs_rtmodify_summary(mp, tp,
 788			XFS_RTBLOCKLOG(postblock - end),
 789			XFS_BITTOBLOCK(mp, end + 1), 1, rbpp, rsb);
 790		if (error) {
 791			return error;
 792		}
 793	}
 794	/*
 795	 * Modify the bitmap to mark this extent allocated.
 796	 */
 797	error = xfs_rtmodify_range(mp, tp, start, len, 0);
 798	return error;
 799}
 800
 801/*
 802 * Return whether there are any free extents in the size range given
 803 * by low and high, for the bitmap block bbno.
 804 */
 805STATIC int				/* error */
 806xfs_rtany_summary(
 807	xfs_mount_t	*mp,		/* file system mount structure */
 808	xfs_trans_t	*tp,		/* transaction pointer */
 809	int		low,		/* low log2 extent size */
 810	int		high,		/* high log2 extent size */
 811	xfs_rtblock_t	bbno,		/* bitmap block number */
 812	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
 813	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 814	int		*stat)		/* out: any good extents here? */
 815{
 816	int		error;		/* error value */
 817	int		log;		/* loop counter, log2 of ext. size */
 818	xfs_suminfo_t	sum;		/* summary data */
 819
 820	/*
 821	 * Loop over logs of extent sizes.  Order is irrelevant.
 822	 */
 823	for (log = low; log <= high; log++) {
 824		/*
 825		 * Get one summary datum.
 826		 */
 827		error = xfs_rtget_summary(mp, tp, log, bbno, rbpp, rsb, &sum);
 828		if (error) {
 829			return error;
 830		}
 831		/*
 832		 * If there are any, return success.
 833		 */
 834		if (sum) {
 835			*stat = 1;
 836			return 0;
 837		}
 838	}
 839	/*
 840	 * Found nothing, return failure.
 841	 */
 842	*stat = 0;
 843	return 0;
 844}
 845
 846/*
 847 * Get a buffer for the bitmap or summary file block specified.
 848 * The buffer is returned read and locked.
 849 */
 850STATIC int				/* error */
 851xfs_rtbuf_get(
 852	xfs_mount_t	*mp,		/* file system mount structure */
 853	xfs_trans_t	*tp,		/* transaction pointer */
 854	xfs_rtblock_t	block,		/* block number in bitmap or summary */
 855	int		issum,		/* is summary not bitmap */
 856	xfs_buf_t	**bpp)		/* output: buffer for the block */
 857{
 858	xfs_buf_t	*bp;		/* block buffer, result */
 859	xfs_daddr_t	d;		/* disk addr of block */
 860	int		error;		/* error value */
 861	xfs_fsblock_t	fsb;		/* fs block number for block */
 862	xfs_inode_t	*ip;		/* bitmap or summary inode */
 
 
 
 863
 864	ip = issum ? mp->m_rsumip : mp->m_rbmip;
 865	/*
 866	 * Map from the file offset (block) and inode number to the
 867	 * file system block.
 868	 */
 869	error = xfs_bmapi_single(tp, ip, XFS_DATA_FORK, &fsb, block);
 870	if (error) {
 871		return error;
 872	}
 873	ASSERT(fsb != NULLFSBLOCK);
 874	/*
 875	 * Convert to disk address for buffer cache.
 876	 */
 877	d = XFS_FSB_TO_DADDR(mp, fsb);
 878	/*
 879	 * Read the buffer.
 880	 */
 881	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
 882				   mp->m_bsize, 0, &bp);
 883	if (error) {
 884		return error;
 885	}
 886	ASSERT(!xfs_buf_geterror(bp));
 887	*bpp = bp;
 888	return 0;
 889}
 890
 891#ifdef DEBUG
 892/*
 893 * Check that the given extent (block range) is allocated already.
 894 */
 895STATIC int				/* error */
 896xfs_rtcheck_alloc_range(
 897	xfs_mount_t	*mp,		/* file system mount point */
 898	xfs_trans_t	*tp,		/* transaction pointer */
 899	xfs_rtblock_t	bno,		/* starting block number of extent */
 900	xfs_extlen_t	len,		/* length of extent */
 901	int		*stat)		/* out: 1 for allocated, 0 for not */
 902{
 903	xfs_rtblock_t	new;		/* dummy for xfs_rtcheck_range */
 904
 905	return xfs_rtcheck_range(mp, tp, bno, len, 0, &new, stat);
 906}
 907#endif
 908
 909/*
 910 * Check that the given range is either all allocated (val = 0) or
 911 * all free (val = 1).
 912 */
 913STATIC int				/* error */
 914xfs_rtcheck_range(
 915	xfs_mount_t	*mp,		/* file system mount point */
 916	xfs_trans_t	*tp,		/* transaction pointer */
 917	xfs_rtblock_t	start,		/* starting block number of extent */
 918	xfs_extlen_t	len,		/* length of extent */
 919	int		val,		/* 1 for free, 0 for allocated */
 920	xfs_rtblock_t	*new,		/* out: first block not matching */
 921	int		*stat)		/* out: 1 for matches, 0 for not */
 922{
 923	xfs_rtword_t	*b;		/* current word in buffer */
 924	int		bit;		/* bit number in the word */
 925	xfs_rtblock_t	block;		/* bitmap block number */
 926	xfs_buf_t	*bp;		/* buf for the block */
 927	xfs_rtword_t	*bufp;		/* starting word in buffer */
 928	int		error;		/* error value */
 929	xfs_rtblock_t	i;		/* current bit number rel. to start */
 930	xfs_rtblock_t	lastbit;	/* last useful bit in word */
 931	xfs_rtword_t	mask;		/* mask of relevant bits for value */
 932	xfs_rtword_t	wdiff;		/* difference from wanted value */
 933	int		word;		/* word number in the buffer */
 934
 935	/*
 936	 * Compute starting bitmap block number
 937	 */
 938	block = XFS_BITTOBLOCK(mp, start);
 939	/*
 940	 * Read the bitmap block.
 941	 */
 942	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
 943	if (error) {
 944		return error;
 945	}
 946	bufp = bp->b_addr;
 947	/*
 948	 * Compute the starting word's address, and starting bit.
 949	 */
 950	word = XFS_BITTOWORD(mp, start);
 951	b = &bufp[word];
 952	bit = (int)(start & (XFS_NBWORD - 1));
 953	/*
 954	 * 0 (allocated) => all zero's; 1 (free) => all one's.
 955	 */
 956	val = -val;
 957	/*
 958	 * If not starting on a word boundary, deal with the first
 959	 * (partial) word.
 960	 */
 961	if (bit) {
 962		/*
 963		 * Compute first bit not examined.
 964		 */
 965		lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
 966		/*
 967		 * Mask of relevant bits.
 968		 */
 969		mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
 970		/*
 971		 * Compute difference between actual and desired value.
 972		 */
 973		if ((wdiff = (*b ^ val) & mask)) {
 974			/*
 975			 * Different, compute first wrong bit and return.
 976			 */
 977			xfs_trans_brelse(tp, bp);
 978			i = XFS_RTLOBIT(wdiff) - bit;
 979			*new = start + i;
 980			*stat = 0;
 981			return 0;
 982		}
 983		i = lastbit - bit;
 984		/*
 985		 * Go on to next block if that's where the next word is
 986		 * and we need the next word.
 987		 */
 988		if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
 989			/*
 990			 * If done with this block, get the next one.
 991			 */
 992			xfs_trans_brelse(tp, bp);
 993			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
 994			if (error) {
 995				return error;
 996			}
 997			b = bufp = bp->b_addr;
 998			word = 0;
 999		} else {
1000			/*
1001			 * Go on to the next word in the buffer.
1002			 */
1003			b++;
1004		}
1005	} else {
1006		/*
1007		 * Starting on a word boundary, no partial word.
1008		 */
1009		i = 0;
1010	}
1011	/*
1012	 * Loop over whole words in buffers.  When we use up one buffer
1013	 * we move on to the next one.
1014	 */
1015	while (len - i >= XFS_NBWORD) {
1016		/*
1017		 * Compute difference between actual and desired value.
1018		 */
1019		if ((wdiff = *b ^ val)) {
1020			/*
1021			 * Different, compute first wrong bit and return.
1022			 */
1023			xfs_trans_brelse(tp, bp);
1024			i += XFS_RTLOBIT(wdiff);
1025			*new = start + i;
1026			*stat = 0;
1027			return 0;
1028		}
1029		i += XFS_NBWORD;
1030		/*
1031		 * Go on to next block if that's where the next word is
1032		 * and we need the next word.
1033		 */
1034		if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1035			/*
1036			 * If done with this block, get the next one.
1037			 */
1038			xfs_trans_brelse(tp, bp);
1039			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1040			if (error) {
1041				return error;
1042			}
1043			b = bufp = bp->b_addr;
1044			word = 0;
1045		} else {
1046			/*
1047			 * Go on to the next word in the buffer.
1048			 */
1049			b++;
1050		}
1051	}
1052	/*
1053	 * If not ending on a word boundary, deal with the last
1054	 * (partial) word.
1055	 */
1056	if ((lastbit = len - i)) {
1057		/*
1058		 * Mask of relevant bits.
1059		 */
1060		mask = ((xfs_rtword_t)1 << lastbit) - 1;
1061		/*
1062		 * Compute difference between actual and desired value.
1063		 */
1064		if ((wdiff = (*b ^ val) & mask)) {
1065			/*
1066			 * Different, compute first wrong bit and return.
1067			 */
1068			xfs_trans_brelse(tp, bp);
1069			i += XFS_RTLOBIT(wdiff);
1070			*new = start + i;
1071			*stat = 0;
1072			return 0;
1073		} else
1074			i = len;
1075	}
1076	/*
1077	 * Successful, return.
1078	 */
1079	xfs_trans_brelse(tp, bp);
1080	*new = start + i;
1081	*stat = 1;
1082	return 0;
1083}
1084
1085/*
1086 * Copy and transform the summary file, given the old and new
1087 * parameters in the mount structures.
1088 */
1089STATIC int				/* error */
1090xfs_rtcopy_summary(
1091	xfs_mount_t	*omp,		/* old file system mount point */
1092	xfs_mount_t	*nmp,		/* new file system mount point */
1093	xfs_trans_t	*tp)		/* transaction pointer */
1094{
1095	xfs_rtblock_t	bbno;		/* bitmap block number */
1096	xfs_buf_t	*bp;		/* summary buffer */
1097	int		error;		/* error return value */
1098	int		log;		/* summary level number (log length) */
1099	xfs_suminfo_t	sum;		/* summary data */
1100	xfs_fsblock_t	sumbno;		/* summary block number */
1101
1102	bp = NULL;
1103	for (log = omp->m_rsumlevels - 1; log >= 0; log--) {
1104		for (bbno = omp->m_sb.sb_rbmblocks - 1;
1105		     (xfs_srtblock_t)bbno >= 0;
1106		     bbno--) {
1107			error = xfs_rtget_summary(omp, tp, log, bbno, &bp,
1108				&sumbno, &sum);
1109			if (error)
1110				return error;
1111			if (sum == 0)
1112				continue;
1113			error = xfs_rtmodify_summary(omp, tp, log, bbno, -sum,
1114				&bp, &sumbno);
1115			if (error)
1116				return error;
1117			error = xfs_rtmodify_summary(nmp, tp, log, bbno, sum,
1118				&bp, &sumbno);
1119			if (error)
1120				return error;
1121			ASSERT(sum > 0);
1122		}
1123	}
1124	return 0;
1125}
1126
1127/*
1128 * Searching backward from start to limit, find the first block whose
1129 * allocated/free state is different from start's.
1130 */
1131STATIC int				/* error */
1132xfs_rtfind_back(
1133	xfs_mount_t	*mp,		/* file system mount point */
1134	xfs_trans_t	*tp,		/* transaction pointer */
1135	xfs_rtblock_t	start,		/* starting block to look at */
1136	xfs_rtblock_t	limit,		/* last block to look at */
1137	xfs_rtblock_t	*rtblock)	/* out: start block found */
1138{
1139	xfs_rtword_t	*b;		/* current word in buffer */
1140	int		bit;		/* bit number in the word */
1141	xfs_rtblock_t	block;		/* bitmap block number */
1142	xfs_buf_t	*bp;		/* buf for the block */
1143	xfs_rtword_t	*bufp;		/* starting word in buffer */
1144	int		error;		/* error value */
1145	xfs_rtblock_t	firstbit;	/* first useful bit in the word */
1146	xfs_rtblock_t	i;		/* current bit number rel. to start */
1147	xfs_rtblock_t	len;		/* length of inspected area */
1148	xfs_rtword_t	mask;		/* mask of relevant bits for value */
1149	xfs_rtword_t	want;		/* mask for "good" values */
1150	xfs_rtword_t	wdiff;		/* difference from wanted value */
1151	int		word;		/* word number in the buffer */
1152
1153	/*
1154	 * Compute and read in starting bitmap block for starting block.
1155	 */
1156	block = XFS_BITTOBLOCK(mp, start);
1157	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1158	if (error) {
1159		return error;
1160	}
1161	bufp = bp->b_addr;
1162	/*
1163	 * Get the first word's index & point to it.
1164	 */
1165	word = XFS_BITTOWORD(mp, start);
1166	b = &bufp[word];
1167	bit = (int)(start & (XFS_NBWORD - 1));
1168	len = start - limit + 1;
1169	/*
1170	 * Compute match value, based on the bit at start: if 1 (free)
1171	 * then all-ones, else all-zeroes.
1172	 */
1173	want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
1174	/*
1175	 * If the starting position is not word-aligned, deal with the
1176	 * partial word.
1177	 */
1178	if (bit < XFS_NBWORD - 1) {
1179		/*
1180		 * Calculate first (leftmost) bit number to look at,
1181		 * and mask for all the relevant bits in this word.
1182		 */
1183		firstbit = XFS_RTMAX((xfs_srtblock_t)(bit - len + 1), 0);
1184		mask = (((xfs_rtword_t)1 << (bit - firstbit + 1)) - 1) <<
1185			firstbit;
1186		/*
1187		 * Calculate the difference between the value there
1188		 * and what we're looking for.
1189		 */
1190		if ((wdiff = (*b ^ want) & mask)) {
1191			/*
1192			 * Different.  Mark where we are and return.
1193			 */
1194			xfs_trans_brelse(tp, bp);
1195			i = bit - XFS_RTHIBIT(wdiff);
1196			*rtblock = start - i + 1;
1197			return 0;
1198		}
1199		i = bit - firstbit + 1;
1200		/*
1201		 * Go on to previous block if that's where the previous word is
1202		 * and we need the previous word.
1203		 */
1204		if (--word == -1 && i < len) {
1205			/*
1206			 * If done with this block, get the previous one.
1207			 */
1208			xfs_trans_brelse(tp, bp);
1209			error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
1210			if (error) {
1211				return error;
1212			}
1213			bufp = bp->b_addr;
1214			word = XFS_BLOCKWMASK(mp);
1215			b = &bufp[word];
1216		} else {
1217			/*
1218			 * Go on to the previous word in the buffer.
1219			 */
1220			b--;
1221		}
1222	} else {
1223		/*
1224		 * Starting on a word boundary, no partial word.
1225		 */
1226		i = 0;
1227	}
1228	/*
1229	 * Loop over whole words in buffers.  When we use up one buffer
1230	 * we move on to the previous one.
1231	 */
1232	while (len - i >= XFS_NBWORD) {
1233		/*
1234		 * Compute difference between actual and desired value.
1235		 */
1236		if ((wdiff = *b ^ want)) {
1237			/*
1238			 * Different, mark where we are and return.
1239			 */
1240			xfs_trans_brelse(tp, bp);
1241			i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
1242			*rtblock = start - i + 1;
1243			return 0;
1244		}
1245		i += XFS_NBWORD;
1246		/*
1247		 * Go on to previous block if that's where the previous word is
1248		 * and we need the previous word.
1249		 */
1250		if (--word == -1 && i < len) {
1251			/*
1252			 * If done with this block, get the previous one.
1253			 */
1254			xfs_trans_brelse(tp, bp);
1255			error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
1256			if (error) {
1257				return error;
1258			}
1259			bufp = bp->b_addr;
1260			word = XFS_BLOCKWMASK(mp);
1261			b = &bufp[word];
1262		} else {
1263			/*
1264			 * Go on to the previous word in the buffer.
1265			 */
1266			b--;
1267		}
1268	}
1269	/*
1270	 * If not ending on a word boundary, deal with the last
1271	 * (partial) word.
1272	 */
1273	if (len - i) {
1274		/*
1275		 * Calculate first (leftmost) bit number to look at,
1276		 * and mask for all the relevant bits in this word.
1277		 */
1278		firstbit = XFS_NBWORD - (len - i);
1279		mask = (((xfs_rtword_t)1 << (len - i)) - 1) << firstbit;
1280		/*
1281		 * Compute difference between actual and desired value.
1282		 */
1283		if ((wdiff = (*b ^ want) & mask)) {
1284			/*
1285			 * Different, mark where we are and return.
1286			 */
1287			xfs_trans_brelse(tp, bp);
1288			i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
1289			*rtblock = start - i + 1;
1290			return 0;
1291		} else
1292			i = len;
1293	}
1294	/*
1295	 * No match, return that we scanned the whole area.
1296	 */
1297	xfs_trans_brelse(tp, bp);
1298	*rtblock = start - i + 1;
1299	return 0;
1300}
1301
1302/*
1303 * Searching forward from start to limit, find the first block whose
1304 * allocated/free state is different from start's.
1305 */
1306STATIC int				/* error */
1307xfs_rtfind_forw(
1308	xfs_mount_t	*mp,		/* file system mount point */
1309	xfs_trans_t	*tp,		/* transaction pointer */
1310	xfs_rtblock_t	start,		/* starting block to look at */
1311	xfs_rtblock_t	limit,		/* last block to look at */
1312	xfs_rtblock_t	*rtblock)	/* out: start block found */
1313{
1314	xfs_rtword_t	*b;		/* current word in buffer */
1315	int		bit;		/* bit number in the word */
1316	xfs_rtblock_t	block;		/* bitmap block number */
1317	xfs_buf_t	*bp;		/* buf for the block */
1318	xfs_rtword_t	*bufp;		/* starting word in buffer */
1319	int		error;		/* error value */
1320	xfs_rtblock_t	i;		/* current bit number rel. to start */
1321	xfs_rtblock_t	lastbit;	/* last useful bit in the word */
1322	xfs_rtblock_t	len;		/* length of inspected area */
1323	xfs_rtword_t	mask;		/* mask of relevant bits for value */
1324	xfs_rtword_t	want;		/* mask for "good" values */
1325	xfs_rtword_t	wdiff;		/* difference from wanted value */
1326	int		word;		/* word number in the buffer */
1327
1328	/*
1329	 * Compute and read in starting bitmap block for starting block.
1330	 */
1331	block = XFS_BITTOBLOCK(mp, start);
1332	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1333	if (error) {
1334		return error;
1335	}
1336	bufp = bp->b_addr;
1337	/*
1338	 * Get the first word's index & point to it.
1339	 */
1340	word = XFS_BITTOWORD(mp, start);
1341	b = &bufp[word];
1342	bit = (int)(start & (XFS_NBWORD - 1));
1343	len = limit - start + 1;
1344	/*
1345	 * Compute match value, based on the bit at start: if 1 (free)
1346	 * then all-ones, else all-zeroes.
1347	 */
1348	want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
1349	/*
1350	 * If the starting position is not word-aligned, deal with the
1351	 * partial word.
1352	 */
1353	if (bit) {
1354		/*
1355		 * Calculate last (rightmost) bit number to look at,
1356		 * and mask for all the relevant bits in this word.
1357		 */
1358		lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
1359		mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
1360		/*
1361		 * Calculate the difference between the value there
1362		 * and what we're looking for.
1363		 */
1364		if ((wdiff = (*b ^ want) & mask)) {
1365			/*
1366			 * Different.  Mark where we are and return.
1367			 */
1368			xfs_trans_brelse(tp, bp);
1369			i = XFS_RTLOBIT(wdiff) - bit;
1370			*rtblock = start + i - 1;
1371			return 0;
1372		}
1373		i = lastbit - bit;
1374		/*
1375		 * Go on to next block if that's where the next word is
1376		 * and we need the next word.
1377		 */
1378		if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1379			/*
1380			 * If done with this block, get the previous one.
1381			 */
1382			xfs_trans_brelse(tp, bp);
1383			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1384			if (error) {
1385				return error;
1386			}
1387			b = bufp = bp->b_addr;
1388			word = 0;
1389		} else {
1390			/*
1391			 * Go on to the previous word in the buffer.
1392			 */
1393			b++;
1394		}
1395	} else {
1396		/*
1397		 * Starting on a word boundary, no partial word.
1398		 */
1399		i = 0;
1400	}
1401	/*
1402	 * Loop over whole words in buffers.  When we use up one buffer
1403	 * we move on to the next one.
1404	 */
1405	while (len - i >= XFS_NBWORD) {
1406		/*
1407		 * Compute difference between actual and desired value.
1408		 */
1409		if ((wdiff = *b ^ want)) {
1410			/*
1411			 * Different, mark where we are and return.
1412			 */
1413			xfs_trans_brelse(tp, bp);
1414			i += XFS_RTLOBIT(wdiff);
1415			*rtblock = start + i - 1;
1416			return 0;
1417		}
1418		i += XFS_NBWORD;
1419		/*
1420		 * Go on to next block if that's where the next word is
1421		 * and we need the next word.
1422		 */
1423		if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1424			/*
1425			 * If done with this block, get the next one.
1426			 */
1427			xfs_trans_brelse(tp, bp);
1428			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1429			if (error) {
1430				return error;
1431			}
1432			b = bufp = bp->b_addr;
1433			word = 0;
1434		} else {
1435			/*
1436			 * Go on to the next word in the buffer.
1437			 */
1438			b++;
1439		}
1440	}
1441	/*
1442	 * If not ending on a word boundary, deal with the last
1443	 * (partial) word.
1444	 */
1445	if ((lastbit = len - i)) {
1446		/*
1447		 * Calculate mask for all the relevant bits in this word.
1448		 */
1449		mask = ((xfs_rtword_t)1 << lastbit) - 1;
1450		/*
1451		 * Compute difference between actual and desired value.
1452		 */
1453		if ((wdiff = (*b ^ want) & mask)) {
1454			/*
1455			 * Different, mark where we are and return.
1456			 */
1457			xfs_trans_brelse(tp, bp);
1458			i += XFS_RTLOBIT(wdiff);
1459			*rtblock = start + i - 1;
1460			return 0;
1461		} else
1462			i = len;
1463	}
1464	/*
1465	 * No match, return that we scanned the whole area.
1466	 */
1467	xfs_trans_brelse(tp, bp);
1468	*rtblock = start + i - 1;
1469	return 0;
1470}
1471
1472/*
1473 * Mark an extent specified by start and len freed.
1474 * Updates all the summary information as well as the bitmap.
1475 */
1476STATIC int				/* error */
1477xfs_rtfree_range(
1478	xfs_mount_t	*mp,		/* file system mount point */
1479	xfs_trans_t	*tp,		/* transaction pointer */
1480	xfs_rtblock_t	start,		/* starting block to free */
1481	xfs_extlen_t	len,		/* length to free */
1482	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
1483	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
1484{
1485	xfs_rtblock_t	end;		/* end of the freed extent */
1486	int		error;		/* error value */
1487	xfs_rtblock_t	postblock;	/* first block freed > end */
1488	xfs_rtblock_t	preblock;	/* first block freed < start */
1489
1490	end = start + len - 1;
1491	/*
1492	 * Modify the bitmap to mark this extent freed.
1493	 */
1494	error = xfs_rtmodify_range(mp, tp, start, len, 1);
1495	if (error) {
1496		return error;
1497	}
1498	/*
1499	 * Assume we're freeing out of the middle of an allocated extent.
1500	 * We need to find the beginning and end of the extent so we can
1501	 * properly update the summary.
1502	 */
1503	error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
1504	if (error) {
1505		return error;
1506	}
1507	/*
1508	 * Find the next allocated block (end of allocated extent).
1509	 */
1510	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
1511		&postblock);
1512	if (error)
1513		return error;
1514	/*
1515	 * If there are blocks not being freed at the front of the
1516	 * old extent, add summary data for them to be allocated.
1517	 */
1518	if (preblock < start) {
1519		error = xfs_rtmodify_summary(mp, tp,
1520			XFS_RTBLOCKLOG(start - preblock),
1521			XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
1522		if (error) {
1523			return error;
1524		}
1525	}
1526	/*
1527	 * If there are blocks not being freed at the end of the
1528	 * old extent, add summary data for them to be allocated.
1529	 */
1530	if (postblock > end) {
1531		error = xfs_rtmodify_summary(mp, tp,
1532			XFS_RTBLOCKLOG(postblock - end),
1533			XFS_BITTOBLOCK(mp, end + 1), -1, rbpp, rsb);
1534		if (error) {
1535			return error;
1536		}
1537	}
1538	/*
1539	 * Increment the summary information corresponding to the entire
1540	 * (new) free extent.
1541	 */
1542	error = xfs_rtmodify_summary(mp, tp,
1543		XFS_RTBLOCKLOG(postblock + 1 - preblock),
1544		XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
1545	return error;
1546}
1547
1548/*
1549 * Read and return the summary information for a given extent size,
1550 * bitmap block combination.
1551 * Keeps track of a current summary block, so we don't keep reading
1552 * it from the buffer cache.
1553 */
1554STATIC int				/* error */
1555xfs_rtget_summary(
1556	xfs_mount_t	*mp,		/* file system mount structure */
1557	xfs_trans_t	*tp,		/* transaction pointer */
1558	int		log,		/* log2 of extent size */
1559	xfs_rtblock_t	bbno,		/* bitmap block number */
1560	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
1561	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
1562	xfs_suminfo_t	*sum)		/* out: summary info for this block */
1563{
1564	xfs_buf_t	*bp;		/* buffer for summary block */
1565	int		error;		/* error value */
1566	xfs_fsblock_t	sb;		/* summary fsblock */
1567	int		so;		/* index into the summary file */
1568	xfs_suminfo_t	*sp;		/* pointer to returned data */
1569
1570	/*
1571	 * Compute entry number in the summary file.
1572	 */
1573	so = XFS_SUMOFFS(mp, log, bbno);
1574	/*
1575	 * Compute the block number in the summary file.
1576	 */
1577	sb = XFS_SUMOFFSTOBLOCK(mp, so);
1578	/*
1579	 * If we have an old buffer, and the block number matches, use that.
1580	 */
1581	if (rbpp && *rbpp && *rsb == sb)
1582		bp = *rbpp;
1583	/*
1584	 * Otherwise we have to get the buffer.
1585	 */
1586	else {
1587		/*
1588		 * If there was an old one, get rid of it first.
1589		 */
1590		if (rbpp && *rbpp)
1591			xfs_trans_brelse(tp, *rbpp);
1592		error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
1593		if (error) {
1594			return error;
1595		}
1596		/*
1597		 * Remember this buffer and block for the next call.
1598		 */
1599		if (rbpp) {
1600			*rbpp = bp;
1601			*rsb = sb;
1602		}
1603	}
1604	/*
1605	 * Point to the summary information & copy it out.
1606	 */
1607	sp = XFS_SUMPTR(mp, bp, so);
1608	*sum = *sp;
1609	/*
1610	 * Drop the buffer if we're not asked to remember it.
1611	 */
1612	if (!rbpp)
1613		xfs_trans_brelse(tp, bp);
1614	return 0;
1615}
1616
1617/*
1618 * Set the given range of bitmap bits to the given value.
1619 * Do whatever I/O and logging is required.
1620 */
1621STATIC int				/* error */
1622xfs_rtmodify_range(
1623	xfs_mount_t	*mp,		/* file system mount point */
1624	xfs_trans_t	*tp,		/* transaction pointer */
1625	xfs_rtblock_t	start,		/* starting block to modify */
1626	xfs_extlen_t	len,		/* length of extent to modify */
1627	int		val)		/* 1 for free, 0 for allocated */
1628{
1629	xfs_rtword_t	*b;		/* current word in buffer */
1630	int		bit;		/* bit number in the word */
1631	xfs_rtblock_t	block;		/* bitmap block number */
1632	xfs_buf_t	*bp;		/* buf for the block */
1633	xfs_rtword_t	*bufp;		/* starting word in buffer */
1634	int		error;		/* error value */
1635	xfs_rtword_t	*first;		/* first used word in the buffer */
1636	int		i;		/* current bit number rel. to start */
1637	int		lastbit;	/* last useful bit in word */
1638	xfs_rtword_t	mask;		/* mask o frelevant bits for value */
1639	int		word;		/* word number in the buffer */
1640
1641	/*
1642	 * Compute starting bitmap block number.
1643	 */
1644	block = XFS_BITTOBLOCK(mp, start);
1645	/*
1646	 * Read the bitmap block, and point to its data.
1647	 */
1648	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1649	if (error) {
1650		return error;
1651	}
1652	bufp = bp->b_addr;
1653	/*
1654	 * Compute the starting word's address, and starting bit.
1655	 */
1656	word = XFS_BITTOWORD(mp, start);
1657	first = b = &bufp[word];
1658	bit = (int)(start & (XFS_NBWORD - 1));
1659	/*
1660	 * 0 (allocated) => all zeroes; 1 (free) => all ones.
1661	 */
1662	val = -val;
1663	/*
1664	 * If not starting on a word boundary, deal with the first
1665	 * (partial) word.
1666	 */
1667	if (bit) {
1668		/*
1669		 * Compute first bit not changed and mask of relevant bits.
1670		 */
1671		lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
1672		mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
1673		/*
1674		 * Set/clear the active bits.
1675		 */
1676		if (val)
1677			*b |= mask;
1678		else
1679			*b &= ~mask;
1680		i = lastbit - bit;
1681		/*
1682		 * Go on to the next block if that's where the next word is
1683		 * and we need the next word.
1684		 */
1685		if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1686			/*
1687			 * Log the changed part of this block.
1688			 * Get the next one.
1689			 */
1690			xfs_trans_log_buf(tp, bp,
1691				(uint)((char *)first - (char *)bufp),
1692				(uint)((char *)b - (char *)bufp));
1693			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1694			if (error) {
1695				return error;
1696			}
1697			first = b = bufp = bp->b_addr;
1698			word = 0;
1699		} else {
1700			/*
1701			 * Go on to the next word in the buffer
1702			 */
1703			b++;
1704		}
1705	} else {
1706		/*
1707		 * Starting on a word boundary, no partial word.
1708		 */
1709		i = 0;
1710	}
1711	/*
1712	 * Loop over whole words in buffers.  When we use up one buffer
1713	 * we move on to the next one.
1714	 */
1715	while (len - i >= XFS_NBWORD) {
1716		/*
1717		 * Set the word value correctly.
1718		 */
1719		*b = val;
1720		i += XFS_NBWORD;
1721		/*
1722		 * Go on to the next block if that's where the next word is
1723		 * and we need the next word.
1724		 */
1725		if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1726			/*
1727			 * Log the changed part of this block.
1728			 * Get the next one.
1729			 */
1730			xfs_trans_log_buf(tp, bp,
1731				(uint)((char *)first - (char *)bufp),
1732				(uint)((char *)b - (char *)bufp));
1733			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1734			if (error) {
1735				return error;
1736			}
1737			first = b = bufp = bp->b_addr;
1738			word = 0;
1739		} else {
1740			/*
1741			 * Go on to the next word in the buffer
1742			 */
1743			b++;
1744		}
1745	}
1746	/*
1747	 * If not ending on a word boundary, deal with the last
1748	 * (partial) word.
1749	 */
1750	if ((lastbit = len - i)) {
1751		/*
1752		 * Compute a mask of relevant bits.
1753		 */
1754		bit = 0;
1755		mask = ((xfs_rtword_t)1 << lastbit) - 1;
1756		/*
1757		 * Set/clear the active bits.
1758		 */
1759		if (val)
1760			*b |= mask;
1761		else
1762			*b &= ~mask;
1763		b++;
1764	}
1765	/*
1766	 * Log any remaining changed bytes.
1767	 */
1768	if (b > first)
1769		xfs_trans_log_buf(tp, bp, (uint)((char *)first - (char *)bufp),
1770			(uint)((char *)b - (char *)bufp - 1));
1771	return 0;
1772}
1773
1774/*
1775 * Read and modify the summary information for a given extent size,
1776 * bitmap block combination.
1777 * Keeps track of a current summary block, so we don't keep reading
1778 * it from the buffer cache.
1779 */
1780STATIC int				/* error */
1781xfs_rtmodify_summary(
1782	xfs_mount_t	*mp,		/* file system mount point */
1783	xfs_trans_t	*tp,		/* transaction pointer */
1784	int		log,		/* log2 of extent size */
1785	xfs_rtblock_t	bbno,		/* bitmap block number */
1786	int		delta,		/* change to make to summary info */
1787	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
1788	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
1789{
1790	xfs_buf_t	*bp;		/* buffer for the summary block */
1791	int		error;		/* error value */
1792	xfs_fsblock_t	sb;		/* summary fsblock */
1793	int		so;		/* index into the summary file */
1794	xfs_suminfo_t	*sp;		/* pointer to returned data */
1795
1796	/*
1797	 * Compute entry number in the summary file.
1798	 */
1799	so = XFS_SUMOFFS(mp, log, bbno);
1800	/*
1801	 * Compute the block number in the summary file.
1802	 */
1803	sb = XFS_SUMOFFSTOBLOCK(mp, so);
1804	/*
1805	 * If we have an old buffer, and the block number matches, use that.
1806	 */
1807	if (rbpp && *rbpp && *rsb == sb)
1808		bp = *rbpp;
1809	/*
1810	 * Otherwise we have to get the buffer.
1811	 */
1812	else {
1813		/*
1814		 * If there was an old one, get rid of it first.
1815		 */
1816		if (rbpp && *rbpp)
1817			xfs_trans_brelse(tp, *rbpp);
1818		error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
1819		if (error) {
1820			return error;
1821		}
1822		/*
1823		 * Remember this buffer and block for the next call.
1824		 */
1825		if (rbpp) {
1826			*rbpp = bp;
1827			*rsb = sb;
1828		}
1829	}
1830	/*
1831	 * Point to the summary information, modify and log it.
1832	 */
1833	sp = XFS_SUMPTR(mp, bp, so);
1834	*sp += delta;
1835	xfs_trans_log_buf(tp, bp, (uint)((char *)sp - (char *)bp->b_addr),
1836		(uint)((char *)sp - (char *)bp->b_addr + sizeof(*sp) - 1));
1837	return 0;
1838}
1839
1840/*
1841 * Visible (exported) functions.
1842 */
1843
1844/*
1845 * Grow the realtime area of the filesystem.
1846 */
1847int
1848xfs_growfs_rt(
1849	xfs_mount_t	*mp,		/* mount point for filesystem */
1850	xfs_growfs_rt_t	*in)		/* growfs rt input struct */
1851{
1852	xfs_rtblock_t	bmbno;		/* bitmap block number */
1853	xfs_buf_t	*bp;		/* temporary buffer */
1854	int		error;		/* error return value */
1855	xfs_mount_t	*nmp;		/* new (fake) mount structure */
1856	xfs_drfsbno_t	nrblocks;	/* new number of realtime blocks */
1857	xfs_extlen_t	nrbmblocks;	/* new number of rt bitmap blocks */
1858	xfs_drtbno_t	nrextents;	/* new number of realtime extents */
1859	uint8_t		nrextslog;	/* new log2 of sb_rextents */
1860	xfs_extlen_t	nrsumblocks;	/* new number of summary blocks */
1861	uint		nrsumlevels;	/* new rt summary levels */
1862	uint		nrsumsize;	/* new size of rt summary, bytes */
1863	xfs_sb_t	*nsbp;		/* new superblock */
1864	xfs_extlen_t	rbmblocks;	/* current number of rt bitmap blocks */
1865	xfs_extlen_t	rsumblocks;	/* current number of rt summary blks */
1866	xfs_sb_t	*sbp;		/* old superblock */
1867	xfs_fsblock_t	sumbno;		/* summary block number */
1868
1869	sbp = &mp->m_sb;
1870	/*
1871	 * Initial error checking.
1872	 */
1873	if (!capable(CAP_SYS_ADMIN))
1874		return XFS_ERROR(EPERM);
1875	if (mp->m_rtdev_targp == NULL || mp->m_rbmip == NULL ||
1876	    (nrblocks = in->newblocks) <= sbp->sb_rblocks ||
1877	    (sbp->sb_rblocks && (in->extsize != sbp->sb_rextsize)))
1878		return XFS_ERROR(EINVAL);
1879	if ((error = xfs_sb_validate_fsb_count(sbp, nrblocks)))
1880		return error;
1881	/*
1882	 * Read in the last block of the device, make sure it exists.
1883	 */
1884	bp = xfs_buf_read_uncached(mp, mp->m_rtdev_targp,
1885				XFS_FSB_TO_BB(mp, nrblocks - 1),
1886				XFS_FSB_TO_B(mp, 1), 0);
1887	if (!bp)
1888		return EIO;
1889	xfs_buf_relse(bp);
1890
1891	/*
1892	 * Calculate new parameters.  These are the final values to be reached.
1893	 */
1894	nrextents = nrblocks;
1895	do_div(nrextents, in->extsize);
1896	nrbmblocks = howmany_64(nrextents, NBBY * sbp->sb_blocksize);
1897	nrextslog = xfs_highbit32(nrextents);
1898	nrsumlevels = nrextslog + 1;
1899	nrsumsize = (uint)sizeof(xfs_suminfo_t) * nrsumlevels * nrbmblocks;
1900	nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1901	nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1902	/*
1903	 * New summary size can't be more than half the size of
1904	 * the log.  This prevents us from getting a log overflow,
1905	 * since we'll log basically the whole summary file at once.
1906	 */
1907	if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
1908		return XFS_ERROR(EINVAL);
1909	/*
1910	 * Get the old block counts for bitmap and summary inodes.
1911	 * These can't change since other growfs callers are locked out.
1912	 */
1913	rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_d.di_size);
1914	rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_d.di_size);
1915	/*
1916	 * Allocate space to the bitmap and summary files, as necessary.
1917	 */
1918	error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks, mp->m_rbmip);
1919	if (error)
1920		return error;
1921	error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
1922	if (error)
1923		return error;
1924	/*
1925	 * Allocate a new (fake) mount/sb.
1926	 */
1927	nmp = kmem_alloc(sizeof(*nmp), KM_SLEEP);
1928	/*
1929	 * Loop over the bitmap blocks.
1930	 * We will do everything one bitmap block at a time.
1931	 * Skip the current block if it is exactly full.
1932	 * This also deals with the case where there were no rtextents before.
1933	 */
1934	for (bmbno = sbp->sb_rbmblocks -
1935		     ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
1936	     bmbno < nrbmblocks;
1937	     bmbno++) {
1938		xfs_trans_t	*tp;
1939		int		cancelflags = 0;
1940
1941		*nmp = *mp;
1942		nsbp = &nmp->m_sb;
1943		/*
1944		 * Calculate new sb and mount fields for this round.
1945		 */
1946		nsbp->sb_rextsize = in->extsize;
1947		nsbp->sb_rbmblocks = bmbno + 1;
1948		nsbp->sb_rblocks =
1949			XFS_RTMIN(nrblocks,
1950				  nsbp->sb_rbmblocks * NBBY *
1951				  nsbp->sb_blocksize * nsbp->sb_rextsize);
1952		nsbp->sb_rextents = nsbp->sb_rblocks;
1953		do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
1954		ASSERT(nsbp->sb_rextents != 0);
1955		nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
1956		nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
1957		nrsumsize =
1958			(uint)sizeof(xfs_suminfo_t) * nrsumlevels *
1959			nsbp->sb_rbmblocks;
1960		nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1961		nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1962		/*
1963		 * Start a transaction, get the log reservation.
1964		 */
1965		tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_FREE);
1966		if ((error = xfs_trans_reserve(tp, 0,
1967				XFS_GROWRTFREE_LOG_RES(nmp), 0, 0, 0)))
1968			goto error_cancel;
1969		/*
1970		 * Lock out other callers by grabbing the bitmap inode lock.
1971		 */
1972		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
1973		xfs_trans_ijoin_ref(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
1974		/*
1975		 * Update the bitmap inode's size.
1976		 */
1977		mp->m_rbmip->i_d.di_size =
1978			nsbp->sb_rbmblocks * nsbp->sb_blocksize;
1979		xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1980		cancelflags |= XFS_TRANS_ABORT;
1981		/*
1982		 * Get the summary inode into the transaction.
1983		 */
1984		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL);
1985		xfs_trans_ijoin_ref(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
1986		/*
1987		 * Update the summary inode's size.
1988		 */
1989		mp->m_rsumip->i_d.di_size = nmp->m_rsumsize;
1990		xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
1991		/*
1992		 * Copy summary data from old to new sizes.
1993		 * Do this when the real size (not block-aligned) changes.
1994		 */
1995		if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
1996		    mp->m_rsumlevels != nmp->m_rsumlevels) {
1997			error = xfs_rtcopy_summary(mp, nmp, tp);
1998			if (error)
1999				goto error_cancel;
2000		}
2001		/*
2002		 * Update superblock fields.
2003		 */
2004		if (nsbp->sb_rextsize != sbp->sb_rextsize)
2005			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
2006				nsbp->sb_rextsize - sbp->sb_rextsize);
2007		if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
2008			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
2009				nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
2010		if (nsbp->sb_rblocks != sbp->sb_rblocks)
2011			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
2012				nsbp->sb_rblocks - sbp->sb_rblocks);
2013		if (nsbp->sb_rextents != sbp->sb_rextents)
2014			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
2015				nsbp->sb_rextents - sbp->sb_rextents);
2016		if (nsbp->sb_rextslog != sbp->sb_rextslog)
2017			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
2018				nsbp->sb_rextslog - sbp->sb_rextslog);
2019		/*
2020		 * Free new extent.
2021		 */
2022		bp = NULL;
2023		error = xfs_rtfree_range(nmp, tp, sbp->sb_rextents,
2024			nsbp->sb_rextents - sbp->sb_rextents, &bp, &sumbno);
2025		if (error) {
2026error_cancel:
2027			xfs_trans_cancel(tp, cancelflags);
2028			break;
2029		}
2030		/*
2031		 * Mark more blocks free in the superblock.
2032		 */
2033		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
2034			nsbp->sb_rextents - sbp->sb_rextents);
2035		/*
2036		 * Update mp values into the real mp structure.
2037		 */
2038		mp->m_rsumlevels = nrsumlevels;
2039		mp->m_rsumsize = nrsumsize;
2040
2041		error = xfs_trans_commit(tp, 0);
2042		if (error)
2043			break;
2044	}
2045
2046	/*
2047	 * Free the fake mp structure.
2048	 */
2049	kmem_free(nmp);
2050
2051	return error;
2052}
2053
2054/*
2055 * Allocate an extent in the realtime subvolume, with the usual allocation
2056 * parameters.  The length units are all in realtime extents, as is the
2057 * result block number.
2058 */
2059int					/* error */
2060xfs_rtallocate_extent(
2061	xfs_trans_t	*tp,		/* transaction pointer */
2062	xfs_rtblock_t	bno,		/* starting block number to allocate */
2063	xfs_extlen_t	minlen,		/* minimum length to allocate */
2064	xfs_extlen_t	maxlen,		/* maximum length to allocate */
2065	xfs_extlen_t	*len,		/* out: actual length allocated */
2066	xfs_alloctype_t	type,		/* allocation type XFS_ALLOCTYPE... */
2067	int		wasdel,		/* was a delayed allocation extent */
2068	xfs_extlen_t	prod,		/* extent product factor */
2069	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
2070{
2071	xfs_mount_t	*mp = tp->t_mountp;
2072	int		error;		/* error value */
2073	xfs_rtblock_t	r;		/* result allocated block */
2074	xfs_fsblock_t	sb;		/* summary file block number */
2075	xfs_buf_t	*sumbp;		/* summary file block buffer */
2076
2077	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
2078	ASSERT(minlen > 0 && minlen <= maxlen);
2079
2080	/*
2081	 * If prod is set then figure out what to do to minlen and maxlen.
2082	 */
2083	if (prod > 1) {
2084		xfs_extlen_t	i;
2085
2086		if ((i = maxlen % prod))
2087			maxlen -= i;
2088		if ((i = minlen % prod))
2089			minlen += prod - i;
2090		if (maxlen < minlen) {
2091			*rtblock = NULLRTBLOCK;
2092			return 0;
2093		}
2094	}
2095
2096	sumbp = NULL;
2097	/*
2098	 * Allocate by size, or near another block, or exactly at some block.
2099	 */
2100	switch (type) {
2101	case XFS_ALLOCTYPE_ANY_AG:
2102		error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
2103				&sumbp,	&sb, prod, &r);
2104		break;
2105	case XFS_ALLOCTYPE_NEAR_BNO:
2106		error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
2107				len, &sumbp, &sb, prod, &r);
2108		break;
2109	case XFS_ALLOCTYPE_THIS_BNO:
2110		error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen,
2111				len, &sumbp, &sb, prod, &r);
2112		break;
2113	default:
2114		error = EIO;
2115		ASSERT(0);
2116	}
2117	if (error)
2118		return error;
2119
2120	/*
2121	 * If it worked, update the superblock.
2122	 */
2123	if (r != NULLRTBLOCK) {
2124		long	slen = (long)*len;
2125
2126		ASSERT(*len >= minlen && *len <= maxlen);
2127		if (wasdel)
2128			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -slen);
2129		else
2130			xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -slen);
2131	}
2132	*rtblock = r;
2133	return 0;
2134}
2135
2136/*
2137 * Free an extent in the realtime subvolume.  Length is expressed in
2138 * realtime extents, as is the block number.
2139 */
2140int					/* error */
2141xfs_rtfree_extent(
2142	xfs_trans_t	*tp,		/* transaction pointer */
2143	xfs_rtblock_t	bno,		/* starting block number to free */
2144	xfs_extlen_t	len)		/* length of extent freed */
2145{
2146	int		error;		/* error value */
2147	xfs_mount_t	*mp;		/* file system mount structure */
2148	xfs_fsblock_t	sb;		/* summary file block number */
2149	xfs_buf_t	*sumbp;		/* summary file block buffer */
2150
2151	mp = tp->t_mountp;
2152	/*
2153	 * Synchronize by locking the bitmap inode.
2154	 */
2155	xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
2156	xfs_trans_ijoin_ref(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
2157
2158#if defined(__KERNEL__) && defined(DEBUG)
2159	/*
2160	 * Check to see that this whole range is currently allocated.
2161	 */
2162	{
2163		int	stat;		/* result from checking range */
2164
2165		error = xfs_rtcheck_alloc_range(mp, tp, bno, len, &stat);
2166		if (error) {
2167			return error;
2168		}
2169		ASSERT(stat);
2170	}
2171#endif
2172	sumbp = NULL;
2173	/*
2174	 * Free the range of realtime blocks.
2175	 */
2176	error = xfs_rtfree_range(mp, tp, bno, len, &sumbp, &sb);
2177	if (error) {
2178		return error;
2179	}
2180	/*
2181	 * Mark more blocks free in the superblock.
2182	 */
2183	xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, (long)len);
2184	/*
2185	 * If we've now freed all the blocks, reset the file sequence
2186	 * number to 0.
2187	 */
2188	if (tp->t_frextents_delta + mp->m_sb.sb_frextents ==
2189	    mp->m_sb.sb_rextents) {
2190		if (!(mp->m_rbmip->i_d.di_flags & XFS_DIFLAG_NEWRTBM))
2191			mp->m_rbmip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
2192		*(__uint64_t *)&mp->m_rbmip->i_d.di_atime = 0;
2193		xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
2194	}
2195	return 0;
2196}
2197
2198/*
2199 * Initialize realtime fields in the mount structure.
2200 */
2201int				/* error */
2202xfs_rtmount_init(
2203	xfs_mount_t	*mp)	/* file system mount structure */
2204{
2205	xfs_buf_t	*bp;	/* buffer for last block of subvolume */
2206	xfs_daddr_t	d;	/* address of last block of subvolume */
2207	xfs_sb_t	*sbp;	/* filesystem superblock copy in mount */
2208
2209	sbp = &mp->m_sb;
2210	if (sbp->sb_rblocks == 0)
2211		return 0;
2212	if (mp->m_rtdev_targp == NULL) {
2213		xfs_warn(mp,
2214	"Filesystem has a realtime volume, use rtdev=device option");
2215		return XFS_ERROR(ENODEV);
2216	}
2217	mp->m_rsumlevels = sbp->sb_rextslog + 1;
2218	mp->m_rsumsize =
2219		(uint)sizeof(xfs_suminfo_t) * mp->m_rsumlevels *
2220		sbp->sb_rbmblocks;
2221	mp->m_rsumsize = roundup(mp->m_rsumsize, sbp->sb_blocksize);
2222	mp->m_rbmip = mp->m_rsumip = NULL;
2223	/*
2224	 * Check that the realtime section is an ok size.
2225	 */
2226	d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
2227	if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
2228		xfs_warn(mp, "realtime mount -- %llu != %llu",
2229			(unsigned long long) XFS_BB_TO_FSB(mp, d),
2230			(unsigned long long) mp->m_sb.sb_rblocks);
2231		return XFS_ERROR(EFBIG);
2232	}
2233	bp = xfs_buf_read_uncached(mp, mp->m_rtdev_targp,
2234					d - XFS_FSB_TO_BB(mp, 1),
2235					XFS_FSB_TO_B(mp, 1), 0);
2236	if (!bp) {
2237		xfs_warn(mp, "realtime device size check failed");
2238		return EIO;
2239	}
2240	xfs_buf_relse(bp);
2241	return 0;
2242}
2243
2244/*
2245 * Get the bitmap and summary inodes into the mount structure
2246 * at mount time.
2247 */
2248int					/* error */
2249xfs_rtmount_inodes(
2250	xfs_mount_t	*mp)		/* file system mount structure */
2251{
2252	int		error;		/* error return value */
2253	xfs_sb_t	*sbp;
2254
2255	sbp = &mp->m_sb;
2256	if (sbp->sb_rbmino == NULLFSINO)
2257		return 0;
2258	error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
2259	if (error)
2260		return error;
2261	ASSERT(mp->m_rbmip != NULL);
2262	ASSERT(sbp->sb_rsumino != NULLFSINO);
2263	error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
2264	if (error) {
2265		IRELE(mp->m_rbmip);
2266		return error;
2267	}
2268	ASSERT(mp->m_rsumip != NULL);
2269	return 0;
2270}
2271
2272void
2273xfs_rtunmount_inodes(
2274	struct xfs_mount	*mp)
2275{
2276	if (mp->m_rbmip)
2277		IRELE(mp->m_rbmip);
2278	if (mp->m_rsumip)
2279		IRELE(mp->m_rsumip);
2280}
2281
2282/*
2283 * Pick an extent for allocation at the start of a new realtime file.
2284 * Use the sequence number stored in the atime field of the bitmap inode.
2285 * Translate this to a fraction of the rtextents, and return the product
2286 * of rtextents and the fraction.
2287 * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
2288 */
2289int					/* error */
2290xfs_rtpick_extent(
2291	xfs_mount_t	*mp,		/* file system mount point */
2292	xfs_trans_t	*tp,		/* transaction pointer */
2293	xfs_extlen_t	len,		/* allocation length (rtextents) */
2294	xfs_rtblock_t	*pick)		/* result rt extent */
2295{
2296	xfs_rtblock_t	b;		/* result block */
2297	int		log2;		/* log of sequence number */
2298	__uint64_t	resid;		/* residual after log removed */
2299	__uint64_t	seq;		/* sequence number of file creation */
2300	__uint64_t	*seqp;		/* pointer to seqno in inode */
2301
2302	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
2303
2304	seqp = (__uint64_t *)&mp->m_rbmip->i_d.di_atime;
2305	if (!(mp->m_rbmip->i_d.di_flags & XFS_DIFLAG_NEWRTBM)) {
2306		mp->m_rbmip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
2307		*seqp = 0;
2308	}
2309	seq = *seqp;
2310	if ((log2 = xfs_highbit64(seq)) == -1)
2311		b = 0;
2312	else {
2313		resid = seq - (1ULL << log2);
2314		b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
2315		    (log2 + 1);
2316		if (b >= mp->m_sb.sb_rextents)
2317			b = do_mod(b, mp->m_sb.sb_rextents);
2318		if (b + len > mp->m_sb.sb_rextents)
2319			b = mp->m_sb.sb_rextents - len;
2320	}
2321	*seqp = seq + 1;
2322	xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
2323	*pick = b;
2324	return 0;
2325}