1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   4 * All Rights Reserved.
   5 */
   6#include "xfs.h"
   7#include "xfs_fs.h"
   8#include "xfs_shared.h"
   9#include "xfs_format.h"
  10#include "xfs_log_format.h"
  11#include "xfs_trans_resv.h"
  12#include "xfs_bit.h"
  13#include "xfs_mount.h"
  14#include "xfs_inode.h"
  15#include "xfs_bmap.h"
  16#include "xfs_bmap_btree.h"
  17#include "xfs_trans.h"
  18#include "xfs_trans_space.h"
  19#include "xfs_icache.h"
  20#include "xfs_rtalloc.h"
  21#include "xfs_sb.h"
  22
  23/*
  24 * Read and return the summary information for a given extent size,
  25 * bitmap block combination.
  26 * Keeps track of a current summary block, so we don't keep reading
  27 * it from the buffer cache.
  28 */
  29static int
  30xfs_rtget_summary(
  31	xfs_mount_t	*mp,		/* file system mount structure */
  32	xfs_trans_t	*tp,		/* transaction pointer */
  33	int		log,		/* log2 of extent size */
  34	xfs_rtblock_t	bbno,		/* bitmap block number */
  35	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
  36	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
  37	xfs_suminfo_t	*sum)		/* out: summary info for this block */
  38{
  39	return xfs_rtmodify_summary_int(mp, tp, log, bbno, 0, rbpp, rsb, sum);
  40}
  41
  42/*
  43 * Return whether there are any free extents in the size range given
  44 * by low and high, for the bitmap block bbno.
  45 */
  46STATIC int				/* error */
  47xfs_rtany_summary(
  48	xfs_mount_t	*mp,		/* file system mount structure */
  49	xfs_trans_t	*tp,		/* transaction pointer */
  50	int		low,		/* low log2 extent size */
  51	int		high,		/* high log2 extent size */
  52	xfs_rtblock_t	bbno,		/* bitmap block number */
  53	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
  54	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
  55	int		*stat)		/* out: any good extents here? */
  56{
  57	int		error;		/* error value */
  58	int		log;		/* loop counter, log2 of ext. size */
  59	xfs_suminfo_t	sum;		/* summary data */
  60
  61	/* There are no extents at levels < m_rsum_cache[bbno]. */
  62	if (mp->m_rsum_cache && low < mp->m_rsum_cache[bbno])
  63		low = mp->m_rsum_cache[bbno];
  64
  65	/*
  66	 * Loop over logs of extent sizes.
  67	 */
  68	for (log = low; log <= high; log++) {
  69		/*
  70		 * Get one summary datum.
  71		 */
  72		error = xfs_rtget_summary(mp, tp, log, bbno, rbpp, rsb, &sum);
  73		if (error) {
  74			return error;
  75		}
  76		/*
  77		 * If there are any, return success.
  78		 */
  79		if (sum) {
  80			*stat = 1;
  81			goto out;
  82		}
  83	}
  84	/*
  85	 * Found nothing, return failure.
  86	 */
  87	*stat = 0;
  88out:
  89	/* There were no extents at levels < log. */
  90	if (mp->m_rsum_cache && log > mp->m_rsum_cache[bbno])
  91		mp->m_rsum_cache[bbno] = log;
  92	return 0;
  93}
  94
  95
  96/*
  97 * Copy and transform the summary file, given the old and new
  98 * parameters in the mount structures.
  99 */
 100STATIC int				/* error */
 101xfs_rtcopy_summary(
 102	xfs_mount_t	*omp,		/* old file system mount point */
 103	xfs_mount_t	*nmp,		/* new file system mount point */
 104	xfs_trans_t	*tp)		/* transaction pointer */
 105{
 106	xfs_rtblock_t	bbno;		/* bitmap block number */
 107	struct xfs_buf	*bp;		/* summary buffer */
 108	int		error;		/* error return value */
 109	int		log;		/* summary level number (log length) */
 110	xfs_suminfo_t	sum;		/* summary data */
 111	xfs_fsblock_t	sumbno;		/* summary block number */
 112
 113	bp = NULL;
 114	for (log = omp->m_rsumlevels - 1; log >= 0; log--) {
 115		for (bbno = omp->m_sb.sb_rbmblocks - 1;
 116		     (xfs_srtblock_t)bbno >= 0;
 117		     bbno--) {
 118			error = xfs_rtget_summary(omp, tp, log, bbno, &bp,
 119				&sumbno, &sum);
 120			if (error)
 121				return error;
 122			if (sum == 0)
 123				continue;
 124			error = xfs_rtmodify_summary(omp, tp, log, bbno, -sum,
 125				&bp, &sumbno);
 126			if (error)
 127				return error;
 128			error = xfs_rtmodify_summary(nmp, tp, log, bbno, sum,
 129				&bp, &sumbno);
 130			if (error)
 131				return error;
 132			ASSERT(sum > 0);
 133		}
 134	}
 135	return 0;
 136}
 137/*
 138 * Mark an extent specified by start and len allocated.
 139 * Updates all the summary information as well as the bitmap.
 140 */
 141STATIC int				/* error */
 142xfs_rtallocate_range(
 143	xfs_mount_t	*mp,		/* file system mount point */
 144	xfs_trans_t	*tp,		/* transaction pointer */
 145	xfs_rtblock_t	start,		/* start block to allocate */
 146	xfs_extlen_t	len,		/* length to allocate */
 147	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
 148	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
 149{
 150	xfs_rtblock_t	end;		/* end of the allocated extent */
 151	int		error;		/* error value */
 152	xfs_rtblock_t	postblock = 0;	/* first block allocated > end */
 153	xfs_rtblock_t	preblock = 0;	/* first block allocated < start */
 154
 155	end = start + len - 1;
 156	/*
 157	 * Assume we're allocating out of the middle of a free extent.
 158	 * We need to find the beginning and end of the extent so we can
 159	 * properly update the summary.
 160	 */
 161	error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
 162	if (error) {
 163		return error;
 164	}
 165	/*
 166	 * Find the next allocated block (end of free extent).
 167	 */
 168	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
 169		&postblock);
 170	if (error) {
 171		return error;
 172	}
 173	/*
 174	 * Decrement the summary information corresponding to the entire
 175	 * (old) free extent.
 176	 */
 177	error = xfs_rtmodify_summary(mp, tp,
 178		XFS_RTBLOCKLOG(postblock + 1 - preblock),
 179		XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
 180	if (error) {
 181		return error;
 182	}
 183	/*
 184	 * If there are blocks not being allocated at the front of the
 185	 * old extent, add summary data for them to be free.
 186	 */
 187	if (preblock < start) {
 188		error = xfs_rtmodify_summary(mp, tp,
 189			XFS_RTBLOCKLOG(start - preblock),
 190			XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
 191		if (error) {
 192			return error;
 193		}
 194	}
 195	/*
 196	 * If there are blocks not being allocated at the end of the
 197	 * old extent, add summary data for them to be free.
 198	 */
 199	if (postblock > end) {
 200		error = xfs_rtmodify_summary(mp, tp,
 201			XFS_RTBLOCKLOG(postblock - end),
 202			XFS_BITTOBLOCK(mp, end + 1), 1, rbpp, rsb);
 203		if (error) {
 204			return error;
 205		}
 206	}
 207	/*
 208	 * Modify the bitmap to mark this extent allocated.
 209	 */
 210	error = xfs_rtmodify_range(mp, tp, start, len, 0);
 211	return error;
 212}
 213
 214/*
 215 * Attempt to allocate an extent minlen<=len<=maxlen starting from
 216 * bitmap block bbno.  If we don't get maxlen then use prod to trim
 217 * the length, if given.  Returns error; returns starting block in *rtblock.
 218 * The lengths are all in rtextents.
 219 */
 220STATIC int				/* error */
 221xfs_rtallocate_extent_block(
 222	xfs_mount_t	*mp,		/* file system mount point */
 223	xfs_trans_t	*tp,		/* transaction pointer */
 224	xfs_rtblock_t	bbno,		/* bitmap block number */
 225	xfs_extlen_t	minlen,		/* minimum length to allocate */
 226	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 227	xfs_extlen_t	*len,		/* out: actual length allocated */
 228	xfs_rtblock_t	*nextp,		/* out: next block to try */
 229	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
 230	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 231	xfs_extlen_t	prod,		/* extent product factor */
 232	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 233{
 234	xfs_rtblock_t	besti;		/* best rtblock found so far */
 235	xfs_rtblock_t	bestlen;	/* best length found so far */
 236	xfs_rtblock_t	end;		/* last rtblock in chunk */
 237	int		error;		/* error value */
 238	xfs_rtblock_t	i;		/* current rtblock trying */
 239	xfs_rtblock_t	next;		/* next rtblock to try */
 240	int		stat;		/* status from internal calls */
 241
 242	/*
 243	 * Loop over all the extents starting in this bitmap block,
 244	 * looking for one that's long enough.
 245	 */
 246	for (i = XFS_BLOCKTOBIT(mp, bbno), besti = -1, bestlen = 0,
 247		end = XFS_BLOCKTOBIT(mp, bbno + 1) - 1;
 248	     i <= end;
 249	     i++) {
 250		/* Make sure we don't scan off the end of the rt volume. */
 251		maxlen = min(mp->m_sb.sb_rextents, i + maxlen) - i;
 252
 253		/*
 254		 * See if there's a free extent of maxlen starting at i.
 255		 * If it's not so then next will contain the first non-free.
 256		 */
 257		error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, &next, &stat);
 258		if (error) {
 259			return error;
 260		}
 261		if (stat) {
 262			/*
 263			 * i for maxlen is all free, allocate and return that.
 264			 */
 265			error = xfs_rtallocate_range(mp, tp, i, maxlen, rbpp,
 266				rsb);
 267			if (error) {
 268				return error;
 269			}
 270			*len = maxlen;
 271			*rtblock = i;
 272			return 0;
 273		}
 274		/*
 275		 * In the case where we have a variable-sized allocation
 276		 * request, figure out how big this free piece is,
 277		 * and if it's big enough for the minimum, and the best
 278		 * so far, remember it.
 279		 */
 280		if (minlen < maxlen) {
 281			xfs_rtblock_t	thislen;	/* this extent size */
 282
 283			thislen = next - i;
 284			if (thislen >= minlen && thislen > bestlen) {
 285				besti = i;
 286				bestlen = thislen;
 287			}
 288		}
 289		/*
 290		 * If not done yet, find the start of the next free space.
 291		 */
 292		if (next < end) {
 293			error = xfs_rtfind_forw(mp, tp, next, end, &i);
 294			if (error) {
 295				return error;
 296			}
 297		} else
 298			break;
 299	}
 300	/*
 301	 * Searched the whole thing & didn't find a maxlen free extent.
 302	 */
 303	if (minlen < maxlen && besti != -1) {
 304		xfs_extlen_t	p;	/* amount to trim length by */
 305
 306		/*
 307		 * If size should be a multiple of prod, make that so.
 308		 */
 309		if (prod > 1) {
 310			div_u64_rem(bestlen, prod, &p);
 311			if (p)
 312				bestlen -= p;
 313		}
 314
 315		/*
 316		 * Allocate besti for bestlen & return that.
 317		 */
 318		error = xfs_rtallocate_range(mp, tp, besti, bestlen, rbpp, rsb);
 319		if (error) {
 320			return error;
 321		}
 322		*len = bestlen;
 323		*rtblock = besti;
 324		return 0;
 325	}
 326	/*
 327	 * Allocation failed.  Set *nextp to the next block to try.
 328	 */
 329	*nextp = next;
 330	*rtblock = NULLRTBLOCK;
 331	return 0;
 332}
 333
 334/*
 335 * Allocate an extent of length minlen<=len<=maxlen, starting at block
 336 * bno.  If we don't get maxlen then use prod to trim the length, if given.
 337 * Returns error; returns starting block in *rtblock.
 338 * The lengths are all in rtextents.
 339 */
 340STATIC int				/* error */
 341xfs_rtallocate_extent_exact(
 342	xfs_mount_t	*mp,		/* file system mount point */
 343	xfs_trans_t	*tp,		/* transaction pointer */
 344	xfs_rtblock_t	bno,		/* starting block number to allocate */
 345	xfs_extlen_t	minlen,		/* minimum length to allocate */
 346	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 347	xfs_extlen_t	*len,		/* out: actual length allocated */
 348	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
 349	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 350	xfs_extlen_t	prod,		/* extent product factor */
 351	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 352{
 353	int		error;		/* error value */
 354	xfs_extlen_t	i;		/* extent length trimmed due to prod */
 355	int		isfree;		/* extent is free */
 356	xfs_rtblock_t	next;		/* next block to try (dummy) */
 357
 358	ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 359	/*
 360	 * Check if the range in question (for maxlen) is free.
 361	 */
 362	error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, &next, &isfree);
 363	if (error) {
 364		return error;
 365	}
 366	if (isfree) {
 367		/*
 368		 * If it is, allocate it and return success.
 369		 */
 370		error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
 371		if (error) {
 372			return error;
 373		}
 374		*len = maxlen;
 375		*rtblock = bno;
 376		return 0;
 377	}
 378	/*
 379	 * If not, allocate what there is, if it's at least minlen.
 380	 */
 381	maxlen = next - bno;
 382	if (maxlen < minlen) {
 383		/*
 384		 * Failed, return failure status.
 385		 */
 386		*rtblock = NULLRTBLOCK;
 387		return 0;
 388	}
 389	/*
 390	 * Trim off tail of extent, if prod is specified.
 391	 */
 392	if (prod > 1 && (i = maxlen % prod)) {
 393		maxlen -= i;
 394		if (maxlen < minlen) {
 395			/*
 396			 * Now we can't do it, return failure status.
 397			 */
 398			*rtblock = NULLRTBLOCK;
 399			return 0;
 400		}
 401	}
 402	/*
 403	 * Allocate what we can and return it.
 404	 */
 405	error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
 406	if (error) {
 407		return error;
 408	}
 409	*len = maxlen;
 410	*rtblock = bno;
 411	return 0;
 412}
 413
 414/*
 415 * Allocate an extent of length minlen<=len<=maxlen, starting as near
 416 * to bno as possible.  If we don't get maxlen then use prod to trim
 417 * the length, if given.  The lengths are all in rtextents.
 418 */
 419STATIC int				/* error */
 420xfs_rtallocate_extent_near(
 421	xfs_mount_t	*mp,		/* file system mount point */
 422	xfs_trans_t	*tp,		/* transaction pointer */
 423	xfs_rtblock_t	bno,		/* starting block number to allocate */
 424	xfs_extlen_t	minlen,		/* minimum length to allocate */
 425	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 426	xfs_extlen_t	*len,		/* out: actual length allocated */
 427	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
 428	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 429	xfs_extlen_t	prod,		/* extent product factor */
 430	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 431{
 432	int		any;		/* any useful extents from summary */
 433	xfs_rtblock_t	bbno;		/* bitmap block number */
 434	int		error;		/* error value */
 435	int		i;		/* bitmap block offset (loop control) */
 436	int		j;		/* secondary loop control */
 437	int		log2len;	/* log2 of minlen */
 438	xfs_rtblock_t	n;		/* next block to try */
 439	xfs_rtblock_t	r;		/* result block */
 440
 441	ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 442	/*
 443	 * If the block number given is off the end, silently set it to
 444	 * the last block.
 445	 */
 446	if (bno >= mp->m_sb.sb_rextents)
 447		bno = mp->m_sb.sb_rextents - 1;
 448
 449	/* Make sure we don't run off the end of the rt volume. */
 450	maxlen = min(mp->m_sb.sb_rextents, bno + maxlen) - bno;
 451	if (maxlen < minlen) {
 452		*rtblock = NULLRTBLOCK;
 453		return 0;
 454	}
 455
 456	/*
 457	 * Try the exact allocation first.
 458	 */
 459	error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
 460		rbpp, rsb, prod, &r);
 461	if (error) {
 462		return error;
 463	}
 464	/*
 465	 * If the exact allocation worked, return that.
 466	 */
 467	if (r != NULLRTBLOCK) {
 468		*rtblock = r;
 469		return 0;
 470	}
 471	bbno = XFS_BITTOBLOCK(mp, bno);
 472	i = 0;
 473	ASSERT(minlen != 0);
 474	log2len = xfs_highbit32(minlen);
 475	/*
 476	 * Loop over all bitmap blocks (bbno + i is current block).
 477	 */
 478	for (;;) {
 479		/*
 480		 * Get summary information of extents of all useful levels
 481		 * starting in this bitmap block.
 482		 */
 483		error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
 484			bbno + i, rbpp, rsb, &any);
 485		if (error) {
 486			return error;
 487		}
 488		/*
 489		 * If there are any useful extents starting here, try
 490		 * allocating one.
 491		 */
 492		if (any) {
 493			/*
 494			 * On the positive side of the starting location.
 495			 */
 496			if (i >= 0) {
 497				/*
 498				 * Try to allocate an extent starting in
 499				 * this block.
 500				 */
 501				error = xfs_rtallocate_extent_block(mp, tp,
 502					bbno + i, minlen, maxlen, len, &n, rbpp,
 503					rsb, prod, &r);
 504				if (error) {
 505					return error;
 506				}
 507				/*
 508				 * If it worked, return it.
 509				 */
 510				if (r != NULLRTBLOCK) {
 511					*rtblock = r;
 512					return 0;
 513				}
 514			}
 515			/*
 516			 * On the negative side of the starting location.
 517			 */
 518			else {		/* i < 0 */
 519				/*
 520				 * Loop backwards through the bitmap blocks from
 521				 * the starting point-1 up to where we are now.
 522				 * There should be an extent which ends in this
 523				 * bitmap block and is long enough.
 524				 */
 525				for (j = -1; j > i; j--) {
 526					/*
 527					 * Grab the summary information for
 528					 * this bitmap block.
 529					 */
 530					error = xfs_rtany_summary(mp, tp,
 531						log2len, mp->m_rsumlevels - 1,
 532						bbno + j, rbpp, rsb, &any);
 533					if (error) {
 534						return error;
 535					}
 536					/*
 537					 * If there's no extent given in the
 538					 * summary that means the extent we
 539					 * found must carry over from an
 540					 * earlier block.  If there is an
 541					 * extent given, we've already tried
 542					 * that allocation, don't do it again.
 543					 */
 544					if (any)
 545						continue;
 546					error = xfs_rtallocate_extent_block(mp,
 547						tp, bbno + j, minlen, maxlen,
 548						len, &n, rbpp, rsb, prod, &r);
 549					if (error) {
 550						return error;
 551					}
 552					/*
 553					 * If it works, return the extent.
 554					 */
 555					if (r != NULLRTBLOCK) {
 556						*rtblock = r;
 557						return 0;
 558					}
 559				}
 560				/*
 561				 * There weren't intervening bitmap blocks
 562				 * with a long enough extent, or the
 563				 * allocation didn't work for some reason
 564				 * (i.e. it's a little * too short).
 565				 * Try to allocate from the summary block
 566				 * that we found.
 567				 */
 568				error = xfs_rtallocate_extent_block(mp, tp,
 569					bbno + i, minlen, maxlen, len, &n, rbpp,
 570					rsb, prod, &r);
 571				if (error) {
 572					return error;
 573				}
 574				/*
 575				 * If it works, return the extent.
 576				 */
 577				if (r != NULLRTBLOCK) {
 578					*rtblock = r;
 579					return 0;
 580				}
 581			}
 582		}
 583		/*
 584		 * Loop control.  If we were on the positive side, and there's
 585		 * still more blocks on the negative side, go there.
 586		 */
 587		if (i > 0 && (int)bbno - i >= 0)
 588			i = -i;
 589		/*
 590		 * If positive, and no more negative, but there are more
 591		 * positive, go there.
 592		 */
 593		else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
 594			i++;
 595		/*
 596		 * If negative or 0 (just started), and there are positive
 597		 * blocks to go, go there.  The 0 case moves to block 1.
 598		 */
 599		else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
 600			i = 1 - i;
 601		/*
 602		 * If negative or 0 and there are more negative blocks,
 603		 * go there.
 604		 */
 605		else if (i <= 0 && (int)bbno + i > 0)
 606			i--;
 607		/*
 608		 * Must be done.  Return failure.
 609		 */
 610		else
 611			break;
 612	}
 613	*rtblock = NULLRTBLOCK;
 614	return 0;
 615}
 616
 617/*
 618 * Allocate an extent of length minlen<=len<=maxlen, with no position
 619 * specified.  If we don't get maxlen then use prod to trim
 620 * the length, if given.  The lengths are all in rtextents.
 621 */
 622STATIC int				/* error */
 623xfs_rtallocate_extent_size(
 624	xfs_mount_t	*mp,		/* file system mount point */
 625	xfs_trans_t	*tp,		/* transaction pointer */
 626	xfs_extlen_t	minlen,		/* minimum length to allocate */
 627	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 628	xfs_extlen_t	*len,		/* out: actual length allocated */
 629	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
 630	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 631	xfs_extlen_t	prod,		/* extent product factor */
 632	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 633{
 634	int		error;		/* error value */
 635	int		i;		/* bitmap block number */
 636	int		l;		/* level number (loop control) */
 637	xfs_rtblock_t	n;		/* next block to be tried */
 638	xfs_rtblock_t	r;		/* result block number */
 639	xfs_suminfo_t	sum;		/* summary information for extents */
 640
 641	ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 642	ASSERT(maxlen != 0);
 643
 644	/*
 645	 * Loop over all the levels starting with maxlen.
 646	 * At each level, look at all the bitmap blocks, to see if there
 647	 * are extents starting there that are long enough (>= maxlen).
 648	 * Note, only on the initial level can the allocation fail if
 649	 * the summary says there's an extent.
 650	 */
 651	for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) {
 652		/*
 653		 * Loop over all the bitmap blocks.
 654		 */
 655		for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
 656			/*
 657			 * Get the summary for this level/block.
 658			 */
 659			error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
 660				&sum);
 661			if (error) {
 662				return error;
 663			}
 664			/*
 665			 * Nothing there, on to the next block.
 666			 */
 667			if (!sum)
 668				continue;
 669			/*
 670			 * Try allocating the extent.
 671			 */
 672			error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
 673				maxlen, len, &n, rbpp, rsb, prod, &r);
 674			if (error) {
 675				return error;
 676			}
 677			/*
 678			 * If it worked, return that.
 679			 */
 680			if (r != NULLRTBLOCK) {
 681				*rtblock = r;
 682				return 0;
 683			}
 684			/*
 685			 * If the "next block to try" returned from the
 686			 * allocator is beyond the next bitmap block,
 687			 * skip to that bitmap block.
 688			 */
 689			if (XFS_BITTOBLOCK(mp, n) > i + 1)
 690				i = XFS_BITTOBLOCK(mp, n) - 1;
 691		}
 692	}
 693	/*
 694	 * Didn't find any maxlen blocks.  Try smaller ones, unless
 695	 * we're asking for a fixed size extent.
 696	 */
 697	if (minlen > --maxlen) {
 698		*rtblock = NULLRTBLOCK;
 699		return 0;
 700	}
 701	ASSERT(minlen != 0);
 702	ASSERT(maxlen != 0);
 703
 704	/*
 705	 * Loop over sizes, from maxlen down to minlen.
 706	 * This time, when we do the allocations, allow smaller ones
 707	 * to succeed.
 708	 */
 709	for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
 710		/*
 711		 * Loop over all the bitmap blocks, try an allocation
 712		 * starting in that block.
 713		 */
 714		for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
 715			/*
 716			 * Get the summary information for this level/block.
 717			 */
 718			error =	xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
 719						  &sum);
 720			if (error) {
 721				return error;
 722			}
 723			/*
 724			 * If nothing there, go on to next.
 725			 */
 726			if (!sum)
 727				continue;
 728			/*
 729			 * Try the allocation.  Make sure the specified
 730			 * minlen/maxlen are in the possible range for
 731			 * this summary level.
 732			 */
 733			error = xfs_rtallocate_extent_block(mp, tp, i,
 734					XFS_RTMAX(minlen, 1 << l),
 735					XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
 736					len, &n, rbpp, rsb, prod, &r);
 737			if (error) {
 738				return error;
 739			}
 740			/*
 741			 * If it worked, return that extent.
 742			 */
 743			if (r != NULLRTBLOCK) {
 744				*rtblock = r;
 745				return 0;
 746			}
 747			/*
 748			 * If the "next block to try" returned from the
 749			 * allocator is beyond the next bitmap block,
 750			 * skip to that bitmap block.
 751			 */
 752			if (XFS_BITTOBLOCK(mp, n) > i + 1)
 753				i = XFS_BITTOBLOCK(mp, n) - 1;
 754		}
 755	}
 756	/*
 757	 * Got nothing, return failure.
 758	 */
 759	*rtblock = NULLRTBLOCK;
 760	return 0;
 761}
 762
 763/*
 764 * Allocate space to the bitmap or summary file, and zero it, for growfs.
 765 */
 766STATIC int
 767xfs_growfs_rt_alloc(
 768	struct xfs_mount	*mp,		/* file system mount point */
 769	xfs_extlen_t		oblocks,	/* old count of blocks */
 770	xfs_extlen_t		nblocks,	/* new count of blocks */
 771	struct xfs_inode	*ip)		/* inode (bitmap/summary) */
 772{
 773	xfs_fileoff_t		bno;		/* block number in file */
 774	struct xfs_buf		*bp;	/* temporary buffer for zeroing */
 775	xfs_daddr_t		d;		/* disk block address */
 776	int			error;		/* error return value */
 777	xfs_fsblock_t		fsbno;		/* filesystem block for bno */
 778	struct xfs_bmbt_irec	map;		/* block map output */
 779	int			nmap;		/* number of block maps */
 780	int			resblks;	/* space reservation */
 781	enum xfs_blft		buf_type;
 782	struct xfs_trans	*tp;
 783
 784	if (ip == mp->m_rsumip)
 785		buf_type = XFS_BLFT_RTSUMMARY_BUF;
 786	else
 787		buf_type = XFS_BLFT_RTBITMAP_BUF;
 788
 789	/*
 790	 * Allocate space to the file, as necessary.
 791	 */
 792	while (oblocks < nblocks) {
 793		resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
 794		/*
 795		 * Reserve space & log for one extent added to the file.
 796		 */
 797		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtalloc, resblks,
 798				0, 0, &tp);
 799		if (error)
 800			return error;
 801		/*
 802		 * Lock the inode.
 803		 */
 804		xfs_ilock(ip, XFS_ILOCK_EXCL);
 805		xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 806
 807		error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
 808				XFS_IEXT_ADD_NOSPLIT_CNT);
 809		if (error == -EFBIG)
 810			error = xfs_iext_count_upgrade(tp, ip,
 811					XFS_IEXT_ADD_NOSPLIT_CNT);
 812		if (error)
 813			goto out_trans_cancel;
 814
 815		/*
 816		 * Allocate blocks to the bitmap file.
 817		 */
 818		nmap = 1;
 819		error = xfs_bmapi_write(tp, ip, oblocks, nblocks - oblocks,
 820					XFS_BMAPI_METADATA, 0, &map, &nmap);
 
 821		if (!error && nmap < 1)
 822			error = -ENOSPC;
 823		if (error)
 824			goto out_trans_cancel;
 825		/*
 826		 * Free any blocks freed up in the transaction, then commit.
 827		 */
 828		error = xfs_trans_commit(tp);
 829		if (error)
 830			return error;
 831		/*
 832		 * Now we need to clear the allocated blocks.
 833		 * Do this one block per transaction, to keep it simple.
 834		 */
 835		for (bno = map.br_startoff, fsbno = map.br_startblock;
 836		     bno < map.br_startoff + map.br_blockcount;
 837		     bno++, fsbno++) {
 838			/*
 839			 * Reserve log for one block zeroing.
 840			 */
 841			error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtzero,
 842					0, 0, 0, &tp);
 843			if (error)
 844				return error;
 845			/*
 846			 * Lock the bitmap inode.
 847			 */
 848			xfs_ilock(ip, XFS_ILOCK_EXCL);
 849			xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 850			/*
 851			 * Get a buffer for the block.
 852			 */
 853			d = XFS_FSB_TO_DADDR(mp, fsbno);
 854			error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
 855					mp->m_bsize, 0, &bp);
 856			if (error)
 
 857				goto out_trans_cancel;
 858
 859			xfs_trans_buf_set_type(tp, bp, buf_type);
 860			bp->b_ops = &xfs_rtbuf_ops;
 861			memset(bp->b_addr, 0, mp->m_sb.sb_blocksize);
 862			xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
 863			/*
 864			 * Commit the transaction.
 865			 */
 866			error = xfs_trans_commit(tp);
 867			if (error)
 868				return error;
 869		}
 870		/*
 871		 * Go on to the next extent, if any.
 872		 */
 873		oblocks = map.br_startoff + map.br_blockcount;
 874	}
 875
 876	return 0;
 877
 878out_trans_cancel:
 879	xfs_trans_cancel(tp);
 880	return error;
 881}
 882
 883static void
 884xfs_alloc_rsum_cache(
 885	xfs_mount_t	*mp,		/* file system mount structure */
 886	xfs_extlen_t	rbmblocks)	/* number of rt bitmap blocks */
 887{
 888	/*
 889	 * The rsum cache is initialized to all zeroes, which is trivially a
 890	 * lower bound on the minimum level with any free extents. We can
 891	 * continue without the cache if it couldn't be allocated.
 892	 */
 893	mp->m_rsum_cache = kvzalloc(rbmblocks, GFP_KERNEL);
 894	if (!mp->m_rsum_cache)
 895		xfs_warn(mp, "could not allocate realtime summary cache");
 896}
 897
 898/*
 899 * Visible (exported) functions.
 900 */
 901
 902/*
 903 * Grow the realtime area of the filesystem.
 904 */
 905int
 906xfs_growfs_rt(
 907	xfs_mount_t	*mp,		/* mount point for filesystem */
 908	xfs_growfs_rt_t	*in)		/* growfs rt input struct */
 909{
 910	xfs_rtblock_t	bmbno;		/* bitmap block number */
 911	struct xfs_buf	*bp;		/* temporary buffer */
 912	int		error;		/* error return value */
 913	xfs_mount_t	*nmp;		/* new (fake) mount structure */
 914	xfs_rfsblock_t	nrblocks;	/* new number of realtime blocks */
 915	xfs_extlen_t	nrbmblocks;	/* new number of rt bitmap blocks */
 916	xfs_rtblock_t	nrextents;	/* new number of realtime extents */
 917	uint8_t		nrextslog;	/* new log2 of sb_rextents */
 918	xfs_extlen_t	nrsumblocks;	/* new number of summary blocks */
 919	uint		nrsumlevels;	/* new rt summary levels */
 920	uint		nrsumsize;	/* new size of rt summary, bytes */
 921	xfs_sb_t	*nsbp;		/* new superblock */
 922	xfs_extlen_t	rbmblocks;	/* current number of rt bitmap blocks */
 923	xfs_extlen_t	rsumblocks;	/* current number of rt summary blks */
 924	xfs_sb_t	*sbp;		/* old superblock */
 925	xfs_fsblock_t	sumbno;		/* summary block number */
 926	uint8_t		*rsum_cache;	/* old summary cache */
 927
 928	sbp = &mp->m_sb;
 929
 930	if (!capable(CAP_SYS_ADMIN))
 931		return -EPERM;
 932
 933	/* Needs to have been mounted with an rt device. */
 934	if (!XFS_IS_REALTIME_MOUNT(mp))
 935		return -EINVAL;
 936	/*
 937	 * Mount should fail if the rt bitmap/summary files don't load, but
 938	 * we'll check anyway.
 939	 */
 940	if (!mp->m_rbmip || !mp->m_rsumip)
 941		return -EINVAL;
 942
 943	/* Shrink not supported. */
 944	if (in->newblocks <= sbp->sb_rblocks)
 945		return -EINVAL;
 946
 947	/* Can only change rt extent size when adding rt volume. */
 948	if (sbp->sb_rblocks > 0 && in->extsize != sbp->sb_rextsize)
 949		return -EINVAL;
 950
 951	/* Range check the extent size. */
 952	if (XFS_FSB_TO_B(mp, in->extsize) > XFS_MAX_RTEXTSIZE ||
 953	    XFS_FSB_TO_B(mp, in->extsize) < XFS_MIN_RTEXTSIZE)
 954		return -EINVAL;
 955
 956	/* Unsupported realtime features. */
 957	if (xfs_has_rmapbt(mp) || xfs_has_reflink(mp))
 958		return -EOPNOTSUPP;
 959
 960	nrblocks = in->newblocks;
 961	error = xfs_sb_validate_fsb_count(sbp, nrblocks);
 962	if (error)
 963		return error;
 964	/*
 965	 * Read in the last block of the device, make sure it exists.
 966	 */
 967	error = xfs_buf_read_uncached(mp->m_rtdev_targp,
 968				XFS_FSB_TO_BB(mp, nrblocks - 1),
 969				XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
 970	if (error)
 971		return error;
 972	xfs_buf_relse(bp);
 973
 974	/*
 975	 * Calculate new parameters.  These are the final values to be reached.
 976	 */
 977	nrextents = nrblocks;
 978	do_div(nrextents, in->extsize);
 979	nrbmblocks = howmany_64(nrextents, NBBY * sbp->sb_blocksize);
 980	nrextslog = xfs_highbit32(nrextents);
 981	nrsumlevels = nrextslog + 1;
 982	nrsumsize = (uint)sizeof(xfs_suminfo_t) * nrsumlevels * nrbmblocks;
 983	nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
 984	nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
 985	/*
 986	 * New summary size can't be more than half the size of
 987	 * the log.  This prevents us from getting a log overflow,
 988	 * since we'll log basically the whole summary file at once.
 989	 */
 990	if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
 991		return -EINVAL;
 992	/*
 993	 * Get the old block counts for bitmap and summary inodes.
 994	 * These can't change since other growfs callers are locked out.
 995	 */
 996	rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_disk_size);
 997	rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_disk_size);
 998	/*
 999	 * Allocate space to the bitmap and summary files, as necessary.
1000	 */
1001	error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks, mp->m_rbmip);
1002	if (error)
1003		return error;
1004	error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
1005	if (error)
1006		return error;
1007
1008	rsum_cache = mp->m_rsum_cache;
1009	if (nrbmblocks != sbp->sb_rbmblocks)
1010		xfs_alloc_rsum_cache(mp, nrbmblocks);
1011
1012	/*
1013	 * Allocate a new (fake) mount/sb.
1014	 */
1015	nmp = kmem_alloc(sizeof(*nmp), 0);
1016	/*
1017	 * Loop over the bitmap blocks.
1018	 * We will do everything one bitmap block at a time.
1019	 * Skip the current block if it is exactly full.
1020	 * This also deals with the case where there were no rtextents before.
1021	 */
1022	for (bmbno = sbp->sb_rbmblocks -
1023		     ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
1024	     bmbno < nrbmblocks;
1025	     bmbno++) {
1026		struct xfs_trans	*tp;
1027		xfs_rfsblock_t		nrblocks_step;
1028
1029		*nmp = *mp;
1030		nsbp = &nmp->m_sb;
1031		/*
1032		 * Calculate new sb and mount fields for this round.
1033		 */
1034		nsbp->sb_rextsize = in->extsize;
1035		nsbp->sb_rbmblocks = bmbno + 1;
1036		nrblocks_step = (bmbno + 1) * NBBY * nsbp->sb_blocksize *
1037				nsbp->sb_rextsize;
1038		nsbp->sb_rblocks = min(nrblocks, nrblocks_step);
 
1039		nsbp->sb_rextents = nsbp->sb_rblocks;
1040		do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
1041		ASSERT(nsbp->sb_rextents != 0);
1042		nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
1043		nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
1044		nrsumsize =
1045			(uint)sizeof(xfs_suminfo_t) * nrsumlevels *
1046			nsbp->sb_rbmblocks;
1047		nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1048		nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1049		/*
1050		 * Start a transaction, get the log reservation.
1051		 */
1052		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtfree, 0, 0, 0,
1053				&tp);
1054		if (error)
1055			break;
1056		/*
1057		 * Lock out other callers by grabbing the bitmap inode lock.
1058		 */
1059		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
1060		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
1061		/*
1062		 * Update the bitmap inode's size ondisk and incore.  We need
1063		 * to update the incore size so that inode inactivation won't
1064		 * punch what it thinks are "posteof" blocks.
1065		 */
1066		mp->m_rbmip->i_disk_size =
1067			nsbp->sb_rbmblocks * nsbp->sb_blocksize;
1068		i_size_write(VFS_I(mp->m_rbmip), mp->m_rbmip->i_disk_size);
1069		xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1070		/*
1071		 * Get the summary inode into the transaction.
1072		 */
1073		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
1074		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
1075		/*
1076		 * Update the summary inode's size.  We need to update the
1077		 * incore size so that inode inactivation won't punch what it
1078		 * thinks are "posteof" blocks.
1079		 */
1080		mp->m_rsumip->i_disk_size = nmp->m_rsumsize;
1081		i_size_write(VFS_I(mp->m_rsumip), mp->m_rsumip->i_disk_size);
1082		xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
1083		/*
1084		 * Copy summary data from old to new sizes.
1085		 * Do this when the real size (not block-aligned) changes.
1086		 */
1087		if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
1088		    mp->m_rsumlevels != nmp->m_rsumlevels) {
1089			error = xfs_rtcopy_summary(mp, nmp, tp);
1090			if (error)
1091				goto error_cancel;
1092		}
1093		/*
1094		 * Update superblock fields.
1095		 */
1096		if (nsbp->sb_rextsize != sbp->sb_rextsize)
1097			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
1098				nsbp->sb_rextsize - sbp->sb_rextsize);
1099		if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
1100			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
1101				nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
1102		if (nsbp->sb_rblocks != sbp->sb_rblocks)
1103			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
1104				nsbp->sb_rblocks - sbp->sb_rblocks);
1105		if (nsbp->sb_rextents != sbp->sb_rextents)
1106			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
1107				nsbp->sb_rextents - sbp->sb_rextents);
1108		if (nsbp->sb_rextslog != sbp->sb_rextslog)
1109			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
1110				nsbp->sb_rextslog - sbp->sb_rextslog);
1111		/*
1112		 * Free new extent.
1113		 */
1114		bp = NULL;
1115		error = xfs_rtfree_range(nmp, tp, sbp->sb_rextents,
1116			nsbp->sb_rextents - sbp->sb_rextents, &bp, &sumbno);
1117		if (error) {
1118error_cancel:
1119			xfs_trans_cancel(tp);
1120			break;
1121		}
1122		/*
1123		 * Mark more blocks free in the superblock.
1124		 */
1125		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
1126			nsbp->sb_rextents - sbp->sb_rextents);
1127		/*
1128		 * Update mp values into the real mp structure.
1129		 */
1130		mp->m_rsumlevels = nrsumlevels;
1131		mp->m_rsumsize = nrsumsize;
1132
1133		error = xfs_trans_commit(tp);
1134		if (error)
1135			break;
1136
1137		/* Ensure the mount RT feature flag is now set. */
1138		mp->m_features |= XFS_FEAT_REALTIME;
1139	}
1140	if (error)
1141		goto out_free;
1142
1143	/* Update secondary superblocks now the physical grow has completed */
1144	error = xfs_update_secondary_sbs(mp);
1145
1146out_free:
1147	/*
1148	 * Free the fake mp structure.
1149	 */
1150	kmem_free(nmp);
1151
1152	/*
1153	 * If we had to allocate a new rsum_cache, we either need to free the
1154	 * old one (if we succeeded) or free the new one and restore the old one
1155	 * (if there was an error).
1156	 */
1157	if (rsum_cache != mp->m_rsum_cache) {
1158		if (error) {
1159			kmem_free(mp->m_rsum_cache);
1160			mp->m_rsum_cache = rsum_cache;
1161		} else {
1162			kmem_free(rsum_cache);
1163		}
1164	}
1165
1166	return error;
1167}
1168
1169/*
1170 * Allocate an extent in the realtime subvolume, with the usual allocation
1171 * parameters.  The length units are all in realtime extents, as is the
1172 * result block number.
1173 */
1174int					/* error */
1175xfs_rtallocate_extent(
1176	xfs_trans_t	*tp,		/* transaction pointer */
1177	xfs_rtblock_t	bno,		/* starting block number to allocate */
1178	xfs_extlen_t	minlen,		/* minimum length to allocate */
1179	xfs_extlen_t	maxlen,		/* maximum length to allocate */
1180	xfs_extlen_t	*len,		/* out: actual length allocated */
1181	int		wasdel,		/* was a delayed allocation extent */
1182	xfs_extlen_t	prod,		/* extent product factor */
1183	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
1184{
1185	xfs_mount_t	*mp = tp->t_mountp;
1186	int		error;		/* error value */
1187	xfs_rtblock_t	r;		/* result allocated block */
1188	xfs_fsblock_t	sb;		/* summary file block number */
1189	struct xfs_buf	*sumbp;		/* summary file block buffer */
1190
1191	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
1192	ASSERT(minlen > 0 && minlen <= maxlen);
1193
1194	/*
1195	 * If prod is set then figure out what to do to minlen and maxlen.
1196	 */
1197	if (prod > 1) {
1198		xfs_extlen_t	i;
1199
1200		if ((i = maxlen % prod))
1201			maxlen -= i;
1202		if ((i = minlen % prod))
1203			minlen += prod - i;
1204		if (maxlen < minlen) {
1205			*rtblock = NULLRTBLOCK;
1206			return 0;
1207		}
1208	}
1209
1210retry:
1211	sumbp = NULL;
1212	if (bno == 0) {
1213		error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
1214				&sumbp,	&sb, prod, &r);
1215	} else {
1216		error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
1217				len, &sumbp, &sb, prod, &r);
1218	}
1219
1220	if (error)
1221		return error;
1222
1223	/*
1224	 * If it worked, update the superblock.
1225	 */
1226	if (r != NULLRTBLOCK) {
1227		long	slen = (long)*len;
1228
1229		ASSERT(*len >= minlen && *len <= maxlen);
1230		if (wasdel)
1231			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -slen);
1232		else
1233			xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -slen);
1234	} else if (prod > 1) {
1235		prod = 1;
1236		goto retry;
1237	}
1238
1239	*rtblock = r;
1240	return 0;
1241}
1242
1243/*
1244 * Initialize realtime fields in the mount structure.
1245 */
1246int				/* error */
1247xfs_rtmount_init(
1248	struct xfs_mount	*mp)	/* file system mount structure */
1249{
1250	struct xfs_buf		*bp;	/* buffer for last block of subvolume */
1251	struct xfs_sb		*sbp;	/* filesystem superblock copy in mount */
1252	xfs_daddr_t		d;	/* address of last block of subvolume */
1253	int			error;
1254
1255	sbp = &mp->m_sb;
1256	if (sbp->sb_rblocks == 0)
1257		return 0;
1258	if (mp->m_rtdev_targp == NULL) {
1259		xfs_warn(mp,
1260	"Filesystem has a realtime volume, use rtdev=device option");
1261		return -ENODEV;
1262	}
1263	mp->m_rsumlevels = sbp->sb_rextslog + 1;
1264	mp->m_rsumsize =
1265		(uint)sizeof(xfs_suminfo_t) * mp->m_rsumlevels *
1266		sbp->sb_rbmblocks;
1267	mp->m_rsumsize = roundup(mp->m_rsumsize, sbp->sb_blocksize);
1268	mp->m_rbmip = mp->m_rsumip = NULL;
1269	/*
1270	 * Check that the realtime section is an ok size.
1271	 */
1272	d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
1273	if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
1274		xfs_warn(mp, "realtime mount -- %llu != %llu",
1275			(unsigned long long) XFS_BB_TO_FSB(mp, d),
1276			(unsigned long long) mp->m_sb.sb_rblocks);
1277		return -EFBIG;
1278	}
1279	error = xfs_buf_read_uncached(mp->m_rtdev_targp,
1280					d - XFS_FSB_TO_BB(mp, 1),
1281					XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
1282	if (error) {
1283		xfs_warn(mp, "realtime device size check failed");
1284		return error;
1285	}
1286	xfs_buf_relse(bp);
1287	return 0;
1288}
1289
1290static int
1291xfs_rtalloc_count_frextent(
1292	struct xfs_mount		*mp,
1293	struct xfs_trans		*tp,
1294	const struct xfs_rtalloc_rec	*rec,
1295	void				*priv)
1296{
1297	uint64_t			*valp = priv;
1298
1299	*valp += rec->ar_extcount;
1300	return 0;
1301}
1302
1303/*
1304 * Reinitialize the number of free realtime extents from the realtime bitmap.
1305 * Callers must ensure that there is no other activity in the filesystem.
1306 */
1307int
1308xfs_rtalloc_reinit_frextents(
1309	struct xfs_mount	*mp)
1310{
1311	uint64_t		val = 0;
1312	int			error;
1313
1314	xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
1315	error = xfs_rtalloc_query_all(mp, NULL, xfs_rtalloc_count_frextent,
1316			&val);
1317	xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
1318	if (error)
1319		return error;
1320
1321	spin_lock(&mp->m_sb_lock);
1322	mp->m_sb.sb_frextents = val;
1323	spin_unlock(&mp->m_sb_lock);
1324	percpu_counter_set(&mp->m_frextents, mp->m_sb.sb_frextents);
1325	return 0;
1326}
1327
1328/*
1329 * Read in the bmbt of an rt metadata inode so that we never have to load them
1330 * at runtime.  This enables the use of shared ILOCKs for rtbitmap scans.  Use
1331 * an empty transaction to avoid deadlocking on loops in the bmbt.
1332 */
1333static inline int
1334xfs_rtmount_iread_extents(
1335	struct xfs_inode	*ip,
1336	unsigned int		lock_class)
1337{
1338	struct xfs_trans	*tp;
1339	int			error;
1340
1341	error = xfs_trans_alloc_empty(ip->i_mount, &tp);
1342	if (error)
1343		return error;
1344
1345	xfs_ilock(ip, XFS_ILOCK_EXCL | lock_class);
1346
1347	error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);
1348	if (error)
1349		goto out_unlock;
1350
1351	if (xfs_inode_has_attr_fork(ip)) {
1352		error = xfs_iread_extents(tp, ip, XFS_ATTR_FORK);
1353		if (error)
1354			goto out_unlock;
1355	}
1356
1357out_unlock:
1358	xfs_iunlock(ip, XFS_ILOCK_EXCL | lock_class);
1359	xfs_trans_cancel(tp);
1360	return error;
1361}
1362
1363/*
1364 * Get the bitmap and summary inodes and the summary cache into the mount
1365 * structure at mount time.
1366 */
1367int					/* error */
1368xfs_rtmount_inodes(
1369	xfs_mount_t	*mp)		/* file system mount structure */
1370{
1371	int		error;		/* error return value */
1372	xfs_sb_t	*sbp;
1373
1374	sbp = &mp->m_sb;
1375	error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
1376	if (error)
1377		return error;
1378	ASSERT(mp->m_rbmip != NULL);
1379
1380	error = xfs_rtmount_iread_extents(mp->m_rbmip, XFS_ILOCK_RTBITMAP);
1381	if (error)
1382		goto out_rele_bitmap;
1383
1384	error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
1385	if (error)
1386		goto out_rele_bitmap;
 
 
1387	ASSERT(mp->m_rsumip != NULL);
1388
1389	error = xfs_rtmount_iread_extents(mp->m_rsumip, XFS_ILOCK_RTSUM);
1390	if (error)
1391		goto out_rele_summary;
1392
1393	xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks);
1394	return 0;
1395
1396out_rele_summary:
1397	xfs_irele(mp->m_rsumip);
1398out_rele_bitmap:
1399	xfs_irele(mp->m_rbmip);
1400	return error;
1401}
1402
1403void
1404xfs_rtunmount_inodes(
1405	struct xfs_mount	*mp)
1406{
1407	kmem_free(mp->m_rsum_cache);
1408	if (mp->m_rbmip)
1409		xfs_irele(mp->m_rbmip);
1410	if (mp->m_rsumip)
1411		xfs_irele(mp->m_rsumip);
1412}
1413
1414/*
1415 * Pick an extent for allocation at the start of a new realtime file.
1416 * Use the sequence number stored in the atime field of the bitmap inode.
1417 * Translate this to a fraction of the rtextents, and return the product
1418 * of rtextents and the fraction.
1419 * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
1420 */
1421int					/* error */
1422xfs_rtpick_extent(
1423	xfs_mount_t	*mp,		/* file system mount point */
1424	xfs_trans_t	*tp,		/* transaction pointer */
1425	xfs_extlen_t	len,		/* allocation length (rtextents) */
1426	xfs_rtblock_t	*pick)		/* result rt extent */
1427{
1428	xfs_rtblock_t	b;		/* result block */
1429	int		log2;		/* log of sequence number */
1430	uint64_t	resid;		/* residual after log removed */
1431	uint64_t	seq;		/* sequence number of file creation */
1432	uint64_t	*seqp;		/* pointer to seqno in inode */
1433
1434	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
1435
1436	seqp = (uint64_t *)&VFS_I(mp->m_rbmip)->i_atime;
1437	if (!(mp->m_rbmip->i_diflags & XFS_DIFLAG_NEWRTBM)) {
1438		mp->m_rbmip->i_diflags |= XFS_DIFLAG_NEWRTBM;
1439		*seqp = 0;
1440	}
1441	seq = *seqp;
1442	if ((log2 = xfs_highbit64(seq)) == -1)
1443		b = 0;
1444	else {
1445		resid = seq - (1ULL << log2);
1446		b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
1447		    (log2 + 1);
1448		if (b >= mp->m_sb.sb_rextents)
1449			div64_u64_rem(b, mp->m_sb.sb_rextents, &b);
1450		if (b + len > mp->m_sb.sb_rextents)
1451			b = mp->m_sb.sb_rextents - len;
1452	}
1453	*seqp = seq + 1;
1454	xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1455	*pick = b;
1456	return 0;
1457}