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_bmap_util.h"
  18#include "xfs_trans.h"
  19#include "xfs_trans_space.h"
  20#include "xfs_icache.h"
  21#include "xfs_rtalloc.h"
  22#include "xfs_sb.h"
  23#include "xfs_rtbitmap.h"
  24#include "xfs_quota.h"
 
 
  25
  26/*
  27 * Return whether there are any free extents in the size range given
  28 * by low and high, for the bitmap block bbno.
  29 */
  30STATIC int
  31xfs_rtany_summary(
  32	struct xfs_rtalloc_args	*args,
  33	int			low,	/* low log2 extent size */
  34	int			high,	/* high log2 extent size */
  35	xfs_fileoff_t		bbno,	/* bitmap block number */
  36	int			*maxlog) /* out: max log2 extent size free */
  37{
  38	struct xfs_mount	*mp = args->mp;
  39	int			error;
  40	int			log;	/* loop counter, log2 of ext. size */
  41	xfs_suminfo_t		sum;	/* summary data */
  42
  43	/* There are no extents at levels >= m_rsum_cache[bbno]. */
  44	if (mp->m_rsum_cache) {
  45		high = min(high, mp->m_rsum_cache[bbno] - 1);
  46		if (low > high) {
  47			*maxlog = -1;
  48			return 0;
  49		}
  50	}
  51
  52	/*
  53	 * Loop over logs of extent sizes.
  54	 */
  55	for (log = high; log >= low; log--) {
  56		/*
  57		 * Get one summary datum.
  58		 */
  59		error = xfs_rtget_summary(args, log, bbno, &sum);
  60		if (error) {
  61			return error;
  62		}
  63		/*
  64		 * If there are any, return success.
  65		 */
  66		if (sum) {
  67			*maxlog = log;
  68			goto out;
  69		}
  70	}
  71	/*
  72	 * Found nothing, return failure.
  73	 */
  74	*maxlog = -1;
  75out:
  76	/* There were no extents at levels > log. */
  77	if (mp->m_rsum_cache && log + 1 < mp->m_rsum_cache[bbno])
  78		mp->m_rsum_cache[bbno] = log + 1;
  79	return 0;
  80}
  81
  82
  83/*
  84 * Copy and transform the summary file, given the old and new
  85 * parameters in the mount structures.
  86 */
  87STATIC int
  88xfs_rtcopy_summary(
  89	struct xfs_rtalloc_args	*oargs,
  90	struct xfs_rtalloc_args	*nargs)
  91{
  92	xfs_fileoff_t		bbno;	/* bitmap block number */
  93	int			error;
  94	int			log;	/* summary level number (log length) */
  95	xfs_suminfo_t		sum;	/* summary data */
  96
  97	for (log = oargs->mp->m_rsumlevels - 1; log >= 0; log--) {
  98		for (bbno = oargs->mp->m_sb.sb_rbmblocks - 1;
  99		     (xfs_srtblock_t)bbno >= 0;
 100		     bbno--) {
 101			error = xfs_rtget_summary(oargs, log, bbno, &sum);
 102			if (error)
 103				goto out;
 104			if (sum == 0)
 105				continue;
 106			error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
 107			if (error)
 108				goto out;
 109			error = xfs_rtmodify_summary(nargs, log, bbno, sum);
 110			if (error)
 111				goto out;
 112			ASSERT(sum > 0);
 113		}
 114	}
 115	error = 0;
 116out:
 117	xfs_rtbuf_cache_relse(oargs);
 118	return 0;
 119}
 120/*
 121 * Mark an extent specified by start and len allocated.
 122 * Updates all the summary information as well as the bitmap.
 123 */
 124STATIC int
 125xfs_rtallocate_range(
 126	struct xfs_rtalloc_args	*args,
 127	xfs_rtxnum_t		start,	/* start rtext to allocate */
 128	xfs_rtxlen_t		len)	/* in/out: summary block number */
 129{
 130	struct xfs_mount	*mp = args->mp;
 131	xfs_rtxnum_t		end;	/* end of the allocated rtext */
 132	int			error;
 133	xfs_rtxnum_t		postblock = 0; /* first rtext allocated > end */
 134	xfs_rtxnum_t		preblock = 0; /* first rtext allocated < start */
 135
 136	end = start + len - 1;
 137	/*
 138	 * Assume we're allocating out of the middle of a free extent.
 139	 * We need to find the beginning and end of the extent so we can
 140	 * properly update the summary.
 141	 */
 142	error = xfs_rtfind_back(args, start, 0, &preblock);
 143	if (error)
 144		return error;
 145
 146	/*
 147	 * Find the next allocated block (end of free extent).
 148	 */
 149	error = xfs_rtfind_forw(args, end, mp->m_sb.sb_rextents - 1,
 150			&postblock);
 151	if (error)
 152		return error;
 153
 154	/*
 155	 * Decrement the summary information corresponding to the entire
 156	 * (old) free extent.
 157	 */
 158	error = xfs_rtmodify_summary(args,
 159			xfs_highbit64(postblock + 1 - preblock),
 160			xfs_rtx_to_rbmblock(mp, preblock), -1);
 161	if (error)
 162		return error;
 163
 164	/*
 165	 * If there are blocks not being allocated at the front of the
 166	 * old extent, add summary data for them to be free.
 167	 */
 168	if (preblock < start) {
 169		error = xfs_rtmodify_summary(args,
 170				xfs_highbit64(start - preblock),
 171				xfs_rtx_to_rbmblock(mp, preblock), 1);
 172		if (error)
 173			return error;
 174	}
 175
 176	/*
 177	 * If there are blocks not being allocated at the end of the
 178	 * old extent, add summary data for them to be free.
 179	 */
 180	if (postblock > end) {
 181		error = xfs_rtmodify_summary(args,
 182				xfs_highbit64(postblock - end),
 183				xfs_rtx_to_rbmblock(mp, end + 1), 1);
 184		if (error)
 185			return error;
 186	}
 187
 188	/*
 189	 * Modify the bitmap to mark this extent allocated.
 190	 */
 191	return xfs_rtmodify_range(args, start, len, 0);
 192}
 193
 194/*
 195 * Make sure we don't run off the end of the rt volume.  Be careful that
 196 * adjusting maxlen downwards doesn't cause us to fail the alignment checks.
 197 */
 198static inline xfs_rtxlen_t
 199xfs_rtallocate_clamp_len(
 200	struct xfs_mount	*mp,
 201	xfs_rtxnum_t		startrtx,
 202	xfs_rtxlen_t		rtxlen,
 203	xfs_rtxlen_t		prod)
 204{
 205	xfs_rtxlen_t		ret;
 206
 207	ret = min(mp->m_sb.sb_rextents, startrtx + rtxlen) - startrtx;
 208	return rounddown(ret, prod);
 209}
 210
 211/*
 212 * Attempt to allocate an extent minlen<=len<=maxlen starting from
 213 * bitmap block bbno.  If we don't get maxlen then use prod to trim
 214 * the length, if given.  Returns error; returns starting block in *rtx.
 215 * The lengths are all in rtextents.
 216 */
 217STATIC int
 218xfs_rtallocate_extent_block(
 219	struct xfs_rtalloc_args	*args,
 220	xfs_fileoff_t		bbno,	/* bitmap block number */
 221	xfs_rtxlen_t		minlen,	/* minimum length to allocate */
 222	xfs_rtxlen_t		maxlen,	/* maximum length to allocate */
 223	xfs_rtxlen_t		*len,	/* out: actual length allocated */
 224	xfs_rtxnum_t		*nextp,	/* out: next rtext to try */
 225	xfs_rtxlen_t		prod,	/* extent product factor */
 226	xfs_rtxnum_t		*rtx)	/* out: start rtext allocated */
 227{
 228	struct xfs_mount	*mp = args->mp;
 229	xfs_rtxnum_t		besti;	/* best rtext found so far */
 230	xfs_rtxnum_t		bestlen;/* best length found so far */
 231	xfs_rtxnum_t		end;	/* last rtext in chunk */
 232	int			error;
 233	xfs_rtxnum_t		i;	/* current rtext trying */
 234	xfs_rtxnum_t		next;	/* next rtext to try */
 235	int			stat;	/* status from internal calls */
 236
 237	/*
 238	 * Loop over all the extents starting in this bitmap block,
 239	 * looking for one that's long enough.
 240	 */
 241	for (i = xfs_rbmblock_to_rtx(mp, bbno), besti = -1, bestlen = 0,
 242		end = xfs_rbmblock_to_rtx(mp, bbno + 1) - 1;
 243	     i <= end;
 244	     i++) {
 245		/* Make sure we don't scan off the end of the rt volume. */
 246		maxlen = xfs_rtallocate_clamp_len(mp, i, maxlen, prod);
 247
 248		/*
 249		 * See if there's a free extent of maxlen starting at i.
 250		 * If it's not so then next will contain the first non-free.
 251		 */
 252		error = xfs_rtcheck_range(args, i, maxlen, 1, &next, &stat);
 253		if (error)
 254			return error;
 255		if (stat) {
 256			/*
 257			 * i for maxlen is all free, allocate and return that.
 258			 */
 259			bestlen = maxlen;
 260			besti = i;
 261			goto allocate;
 262		}
 263
 264		/*
 265		 * In the case where we have a variable-sized allocation
 266		 * request, figure out how big this free piece is,
 267		 * and if it's big enough for the minimum, and the best
 268		 * so far, remember it.
 269		 */
 270		if (minlen < maxlen) {
 271			xfs_rtxnum_t	thislen;	/* this extent size */
 272
 273			thislen = next - i;
 274			if (thislen >= minlen && thislen > bestlen) {
 275				besti = i;
 276				bestlen = thislen;
 277			}
 278		}
 279		/*
 280		 * If not done yet, find the start of the next free space.
 281		 */
 282		if (next >= end)
 283			break;
 284		error = xfs_rtfind_forw(args, next, end, &i);
 285		if (error)
 286			return error;
 287	}
 288
 289	/*
 290	 * Searched the whole thing & didn't find a maxlen free extent.
 291	 */
 292	if (minlen > maxlen || besti == -1) {
 293		/*
 294		 * Allocation failed.  Set *nextp to the next block to try.
 295		 */
 296		*nextp = next;
 297		return -ENOSPC;
 298	}
 299
 300	/*
 301	 * If size should be a multiple of prod, make that so.
 302	 */
 303	if (prod > 1) {
 304		xfs_rtxlen_t	p;	/* amount to trim length by */
 305
 306		div_u64_rem(bestlen, prod, &p);
 307		if (p)
 308			bestlen -= p;
 309	}
 310
 311	/*
 312	 * Allocate besti for bestlen & return that.
 313	 */
 314allocate:
 315	error = xfs_rtallocate_range(args, besti, bestlen);
 316	if (error)
 317		return error;
 318	*len = bestlen;
 319	*rtx = besti;
 320	return 0;
 321}
 322
 323/*
 324 * Allocate an extent of length minlen<=len<=maxlen, starting at block
 325 * bno.  If we don't get maxlen then use prod to trim the length, if given.
 326 * Returns error; returns starting block in *rtx.
 327 * The lengths are all in rtextents.
 328 */
 329STATIC int
 330xfs_rtallocate_extent_exact(
 331	struct xfs_rtalloc_args	*args,
 332	xfs_rtxnum_t		start,	/* starting rtext number to allocate */
 333	xfs_rtxlen_t		minlen,	/* minimum length to allocate */
 334	xfs_rtxlen_t		maxlen,	/* maximum length to allocate */
 335	xfs_rtxlen_t		*len,	/* out: actual length allocated */
 336	xfs_rtxlen_t		prod,	/* extent product factor */
 337	xfs_rtxnum_t		*rtx)	/* out: start rtext allocated */
 338{
 339	int			error;
 340	xfs_rtxlen_t		i;	/* extent length trimmed due to prod */
 341	int			isfree;	/* extent is free */
 342	xfs_rtxnum_t		next;	/* next rtext to try (dummy) */
 343
 344	ASSERT(minlen % prod == 0);
 345	ASSERT(maxlen % prod == 0);
 346	/*
 347	 * Check if the range in question (for maxlen) is free.
 348	 */
 349	error = xfs_rtcheck_range(args, start, maxlen, 1, &next, &isfree);
 350	if (error)
 351		return error;
 352
 353	if (!isfree) {
 354		/*
 355		 * If not, allocate what there is, if it's at least minlen.
 356		 */
 357		maxlen = next - start;
 358		if (maxlen < minlen)
 359			return -ENOSPC;
 360
 361		/*
 362		 * Trim off tail of extent, if prod is specified.
 363		 */
 364		if (prod > 1 && (i = maxlen % prod)) {
 365			maxlen -= i;
 366			if (maxlen < minlen)
 367				return -ENOSPC;
 368		}
 369	}
 370
 371	/*
 372	 * Allocate what we can and return it.
 373	 */
 374	error = xfs_rtallocate_range(args, start, maxlen);
 375	if (error)
 376		return error;
 377	*len = maxlen;
 378	*rtx = start;
 379	return 0;
 380}
 381
 382/*
 383 * Allocate an extent of length minlen<=len<=maxlen, starting as near
 384 * to start as possible.  If we don't get maxlen then use prod to trim
 385 * the length, if given.  The lengths are all in rtextents.
 386 */
 387STATIC int
 388xfs_rtallocate_extent_near(
 389	struct xfs_rtalloc_args	*args,
 390	xfs_rtxnum_t		start,	/* starting rtext number to allocate */
 391	xfs_rtxlen_t		minlen,	/* minimum length to allocate */
 392	xfs_rtxlen_t		maxlen,	/* maximum length to allocate */
 393	xfs_rtxlen_t		*len,	/* out: actual length allocated */
 394	xfs_rtxlen_t		prod,	/* extent product factor */
 395	xfs_rtxnum_t		*rtx)	/* out: start rtext allocated */
 396{
 397	struct xfs_mount	*mp = args->mp;
 398	int			maxlog;	/* max useful extent from summary */
 399	xfs_fileoff_t		bbno;	/* bitmap block number */
 400	int			error;
 401	int			i;	/* bitmap block offset (loop control) */
 402	int			j;	/* secondary loop control */
 403	int			log2len; /* log2 of minlen */
 404	xfs_rtxnum_t		n;	/* next rtext to try */
 405
 406	ASSERT(minlen % prod == 0);
 407	ASSERT(maxlen % prod == 0);
 408
 409	/*
 410	 * If the block number given is off the end, silently set it to
 411	 * the last block.
 412	 */
 413	if (start >= mp->m_sb.sb_rextents)
 414		start = mp->m_sb.sb_rextents - 1;
 415
 416	/* Make sure we don't run off the end of the rt volume. */
 417	maxlen = xfs_rtallocate_clamp_len(mp, start, maxlen, prod);
 418	if (maxlen < minlen)
 419		return -ENOSPC;
 420
 421	/*
 422	 * Try the exact allocation first.
 423	 */
 424	error = xfs_rtallocate_extent_exact(args, start, minlen, maxlen, len,
 425			prod, rtx);
 426	if (error != -ENOSPC)
 427		return error;
 428
 429
 430	bbno = xfs_rtx_to_rbmblock(mp, start);
 431	i = 0;
 432	j = -1;
 433	ASSERT(minlen != 0);
 434	log2len = xfs_highbit32(minlen);
 435	/*
 436	 * Loop over all bitmap blocks (bbno + i is current block).
 437	 */
 438	for (;;) {
 439		/*
 440		 * Get summary information of extents of all useful levels
 441		 * starting in this bitmap block.
 442		 */
 443		error = xfs_rtany_summary(args, log2len, mp->m_rsumlevels - 1,
 444				bbno + i, &maxlog);
 445		if (error)
 446			return error;
 447
 448		/*
 449		 * If there are any useful extents starting here, try
 450		 * allocating one.
 451		 */
 452		if (maxlog >= 0) {
 453			xfs_extlen_t maxavail =
 454				min_t(xfs_rtblock_t, maxlen,
 455				      (1ULL << (maxlog + 1)) - 1);
 456			/*
 457			 * On the positive side of the starting location.
 458			 */
 459			if (i >= 0) {
 460				/*
 461				 * Try to allocate an extent starting in
 462				 * this block.
 463				 */
 464				error = xfs_rtallocate_extent_block(args,
 465						bbno + i, minlen, maxavail, len,
 466						&n, prod, rtx);
 467				if (error != -ENOSPC)
 468					return error;
 469			}
 470			/*
 471			 * On the negative side of the starting location.
 472			 */
 473			else {		/* i < 0 */
 474				int	maxblocks;
 475
 476				/*
 477				 * Loop backwards to find the end of the extent
 478				 * we found in the realtime summary.
 479				 *
 480				 * maxblocks is the maximum possible number of
 481				 * bitmap blocks from the start of the extent
 482				 * to the end of the extent.
 483				 */
 484				if (maxlog == 0)
 485					maxblocks = 0;
 486				else if (maxlog < mp->m_blkbit_log)
 487					maxblocks = 1;
 488				else
 489					maxblocks = 2 << (maxlog - mp->m_blkbit_log);
 490
 491				/*
 492				 * We need to check bbno + i + maxblocks down to
 493				 * bbno + i. We already checked bbno down to
 494				 * bbno + j + 1, so we don't need to check those
 495				 * again.
 496				 */
 497				j = min(i + maxblocks, j);
 498				for (; j >= i; j--) {
 499					error = xfs_rtallocate_extent_block(args,
 500							bbno + j, minlen,
 501							maxavail, len, &n, prod,
 502							rtx);
 503					if (error != -ENOSPC)
 504						return error;
 505				}
 506			}
 507		}
 508		/*
 509		 * Loop control.  If we were on the positive side, and there's
 510		 * still more blocks on the negative side, go there.
 511		 */
 512		if (i > 0 && (int)bbno - i >= 0)
 513			i = -i;
 514		/*
 515		 * If positive, and no more negative, but there are more
 516		 * positive, go there.
 517		 */
 518		else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
 519			i++;
 520		/*
 521		 * If negative or 0 (just started), and there are positive
 522		 * blocks to go, go there.  The 0 case moves to block 1.
 523		 */
 524		else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
 525			i = 1 - i;
 526		/*
 527		 * If negative or 0 and there are more negative blocks,
 528		 * go there.
 529		 */
 530		else if (i <= 0 && (int)bbno + i > 0)
 531			i--;
 532		/*
 533		 * Must be done.  Return failure.
 534		 */
 535		else
 536			break;
 537	}
 538	return -ENOSPC;
 539}
 540
 541static int
 542xfs_rtalloc_sumlevel(
 543	struct xfs_rtalloc_args	*args,
 544	int			l,	/* level number */
 545	xfs_rtxlen_t		minlen,	/* minimum length to allocate */
 546	xfs_rtxlen_t		maxlen,	/* maximum length to allocate */
 547	xfs_rtxlen_t		prod,	/* extent product factor */
 548	xfs_rtxlen_t		*len,	/* out: actual length allocated */
 549	xfs_rtxnum_t		*rtx)	/* out: start rtext allocated */
 550{
 551	xfs_fileoff_t		i;	/* bitmap block number */
 552
 553	for (i = 0; i < args->mp->m_sb.sb_rbmblocks; i++) {
 554		xfs_suminfo_t	sum;	/* summary information for extents */
 555		xfs_rtxnum_t	n;	/* next rtext to be tried */
 556		int		error;
 557
 558		error = xfs_rtget_summary(args, l, i, &sum);
 559		if (error)
 560			return error;
 561
 562		/*
 563		 * Nothing there, on to the next block.
 564		 */
 565		if (!sum)
 566			continue;
 567
 568		/*
 569		 * Try allocating the extent.
 570		 */
 571		error = xfs_rtallocate_extent_block(args, i, minlen, maxlen,
 572				len, &n, prod, rtx);
 573		if (error != -ENOSPC)
 574			return error;
 575
 576		/*
 577		 * If the "next block to try" returned from the allocator is
 578		 * beyond the next bitmap block, skip to that bitmap block.
 579		 */
 580		if (xfs_rtx_to_rbmblock(args->mp, n) > i + 1)
 581			i = xfs_rtx_to_rbmblock(args->mp, n) - 1;
 582	}
 583
 584	return -ENOSPC;
 585}
 586
 587/*
 588 * Allocate an extent of length minlen<=len<=maxlen, with no position
 589 * specified.  If we don't get maxlen then use prod to trim
 590 * the length, if given.  The lengths are all in rtextents.
 591 */
 592STATIC int
 593xfs_rtallocate_extent_size(
 594	struct xfs_rtalloc_args	*args,
 595	xfs_rtxlen_t		minlen,	/* minimum length to allocate */
 596	xfs_rtxlen_t		maxlen,	/* maximum length to allocate */
 597	xfs_rtxlen_t		*len,	/* out: actual length allocated */
 598	xfs_rtxlen_t		prod,	/* extent product factor */
 599	xfs_rtxnum_t		*rtx)	/* out: start rtext allocated */
 600{
 601	int			error;
 602	int			l;	/* level number (loop control) */
 603
 604	ASSERT(minlen % prod == 0);
 605	ASSERT(maxlen % prod == 0);
 606	ASSERT(maxlen != 0);
 607
 608	/*
 609	 * Loop over all the levels starting with maxlen.
 610	 *
 611	 * At each level, look at all the bitmap blocks, to see if there are
 612	 * extents starting there that are long enough (>= maxlen).
 613	 *
 614	 * Note, only on the initial level can the allocation fail if the
 615	 * summary says there's an extent.
 616	 */
 617	for (l = xfs_highbit32(maxlen); l < args->mp->m_rsumlevels; l++) {
 618		error = xfs_rtalloc_sumlevel(args, l, minlen, maxlen, prod, len,
 619				rtx);
 620		if (error != -ENOSPC)
 621			return error;
 622	}
 623
 624	/*
 625	 * Didn't find any maxlen blocks.  Try smaller ones, unless we are
 626	 * looking for a fixed size extent.
 627	 */
 628	if (minlen > --maxlen)
 629		return -ENOSPC;
 630	ASSERT(minlen != 0);
 631	ASSERT(maxlen != 0);
 632
 633	/*
 634	 * Loop over sizes, from maxlen down to minlen.
 635	 *
 636	 * This time, when we do the allocations, allow smaller ones to succeed,
 637	 * but make sure the specified minlen/maxlen are in the possible range
 638	 * for this summary level.
 639	 */
 640	for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
 641		error = xfs_rtalloc_sumlevel(args, l,
 642				max_t(xfs_rtxlen_t, minlen, 1 << l),
 643				min_t(xfs_rtxlen_t, maxlen, (1 << (l + 1)) - 1),
 644				prod, len, rtx);
 645		if (error != -ENOSPC)
 646			return error;
 647	}
 648
 649	return -ENOSPC;
 650}
 651
 652/*
 653 * Allocate space to the bitmap or summary file, and zero it, for growfs.
 654 */
 655STATIC int
 656xfs_growfs_rt_alloc(
 657	struct xfs_mount	*mp,		/* file system mount point */
 658	xfs_extlen_t		oblocks,	/* old count of blocks */
 659	xfs_extlen_t		nblocks,	/* new count of blocks */
 660	struct xfs_inode	*ip)		/* inode (bitmap/summary) */
 661{
 662	xfs_fileoff_t		bno;		/* block number in file */
 663	struct xfs_buf		*bp;	/* temporary buffer for zeroing */
 664	xfs_daddr_t		d;		/* disk block address */
 665	int			error;		/* error return value */
 666	xfs_fsblock_t		fsbno;		/* filesystem block for bno */
 667	struct xfs_bmbt_irec	map;		/* block map output */
 668	int			nmap;		/* number of block maps */
 669	int			resblks;	/* space reservation */
 670	enum xfs_blft		buf_type;
 671	struct xfs_trans	*tp;
 672
 673	if (ip == mp->m_rsumip)
 674		buf_type = XFS_BLFT_RTSUMMARY_BUF;
 675	else
 676		buf_type = XFS_BLFT_RTBITMAP_BUF;
 677
 678	/*
 679	 * Allocate space to the file, as necessary.
 680	 */
 681	while (oblocks < nblocks) {
 682		resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
 683		/*
 684		 * Reserve space & log for one extent added to the file.
 685		 */
 686		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtalloc, resblks,
 687				0, 0, &tp);
 688		if (error)
 689			return error;
 690		/*
 691		 * Lock the inode.
 692		 */
 693		xfs_ilock(ip, XFS_ILOCK_EXCL);
 694		xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 695
 696		error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
 697				XFS_IEXT_ADD_NOSPLIT_CNT);
 698		if (error == -EFBIG)
 699			error = xfs_iext_count_upgrade(tp, ip,
 700					XFS_IEXT_ADD_NOSPLIT_CNT);
 701		if (error)
 702			goto out_trans_cancel;
 703
 704		/*
 705		 * Allocate blocks to the bitmap file.
 706		 */
 707		nmap = 1;
 708		error = xfs_bmapi_write(tp, ip, oblocks, nblocks - oblocks,
 709					XFS_BMAPI_METADATA, 0, &map, &nmap);
 710		if (!error && nmap < 1)
 711			error = -ENOSPC;
 712		if (error)
 713			goto out_trans_cancel;
 714		/*
 715		 * Free any blocks freed up in the transaction, then commit.
 716		 */
 717		error = xfs_trans_commit(tp);
 718		if (error)
 719			return error;
 720		/*
 721		 * Now we need to clear the allocated blocks.
 722		 * Do this one block per transaction, to keep it simple.
 723		 */
 724		for (bno = map.br_startoff, fsbno = map.br_startblock;
 725		     bno < map.br_startoff + map.br_blockcount;
 726		     bno++, fsbno++) {
 727			/*
 728			 * Reserve log for one block zeroing.
 729			 */
 730			error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtzero,
 731					0, 0, 0, &tp);
 732			if (error)
 733				return error;
 734			/*
 735			 * Lock the bitmap inode.
 736			 */
 737			xfs_ilock(ip, XFS_ILOCK_EXCL);
 738			xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 739			/*
 740			 * Get a buffer for the block.
 741			 */
 742			d = XFS_FSB_TO_DADDR(mp, fsbno);
 743			error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
 744					mp->m_bsize, 0, &bp);
 745			if (error)
 746				goto out_trans_cancel;
 747
 748			xfs_trans_buf_set_type(tp, bp, buf_type);
 749			bp->b_ops = &xfs_rtbuf_ops;
 750			memset(bp->b_addr, 0, mp->m_sb.sb_blocksize);
 751			xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
 752			/*
 753			 * Commit the transaction.
 754			 */
 755			error = xfs_trans_commit(tp);
 756			if (error)
 757				return error;
 758		}
 759		/*
 760		 * Go on to the next extent, if any.
 761		 */
 762		oblocks = map.br_startoff + map.br_blockcount;
 763	}
 764
 765	return 0;
 766
 767out_trans_cancel:
 768	xfs_trans_cancel(tp);
 769	return error;
 770}
 771
 772static void
 773xfs_alloc_rsum_cache(
 774	xfs_mount_t	*mp,		/* file system mount structure */
 775	xfs_extlen_t	rbmblocks)	/* number of rt bitmap blocks */
 776{
 777	/*
 778	 * The rsum cache is initialized to the maximum value, which is
 779	 * trivially an upper bound on the maximum level with any free extents.
 780	 * We can continue without the cache if it couldn't be allocated.
 781	 */
 782	mp->m_rsum_cache = kvmalloc(rbmblocks, GFP_KERNEL);
 783	if (mp->m_rsum_cache)
 784		memset(mp->m_rsum_cache, -1, rbmblocks);
 785	else
 786		xfs_warn(mp, "could not allocate realtime summary cache");
 787}
 788
 789/*
 790 * Visible (exported) functions.
 791 */
 792
 793/*
 794 * Grow the realtime area of the filesystem.
 795 */
 796int
 797xfs_growfs_rt(
 798	xfs_mount_t	*mp,		/* mount point for filesystem */
 799	xfs_growfs_rt_t	*in)		/* growfs rt input struct */
 800{
 801	xfs_fileoff_t	bmbno;		/* bitmap block number */
 802	struct xfs_buf	*bp;		/* temporary buffer */
 803	int		error;		/* error return value */
 804	xfs_mount_t	*nmp;		/* new (fake) mount structure */
 805	xfs_rfsblock_t	nrblocks;	/* new number of realtime blocks */
 806	xfs_extlen_t	nrbmblocks;	/* new number of rt bitmap blocks */
 807	xfs_rtxnum_t	nrextents;	/* new number of realtime extents */
 808	uint8_t		nrextslog;	/* new log2 of sb_rextents */
 809	xfs_extlen_t	nrsumblocks;	/* new number of summary blocks */
 810	uint		nrsumlevels;	/* new rt summary levels */
 811	uint		nrsumsize;	/* new size of rt summary, bytes */
 812	xfs_sb_t	*nsbp;		/* new superblock */
 813	xfs_extlen_t	rbmblocks;	/* current number of rt bitmap blocks */
 814	xfs_extlen_t	rsumblocks;	/* current number of rt summary blks */
 815	xfs_sb_t	*sbp;		/* old superblock */
 816	uint8_t		*rsum_cache;	/* old summary cache */
 817
 818	sbp = &mp->m_sb;
 819
 820	if (!capable(CAP_SYS_ADMIN))
 821		return -EPERM;
 822
 823	/* Needs to have been mounted with an rt device. */
 824	if (!XFS_IS_REALTIME_MOUNT(mp))
 825		return -EINVAL;
 826	/*
 827	 * Mount should fail if the rt bitmap/summary files don't load, but
 828	 * we'll check anyway.
 829	 */
 830	if (!mp->m_rbmip || !mp->m_rsumip)
 831		return -EINVAL;
 832
 833	/* Shrink not supported. */
 834	if (in->newblocks <= sbp->sb_rblocks)
 835		return -EINVAL;
 836
 837	/* Can only change rt extent size when adding rt volume. */
 838	if (sbp->sb_rblocks > 0 && in->extsize != sbp->sb_rextsize)
 839		return -EINVAL;
 840
 841	/* Range check the extent size. */
 842	if (XFS_FSB_TO_B(mp, in->extsize) > XFS_MAX_RTEXTSIZE ||
 843	    XFS_FSB_TO_B(mp, in->extsize) < XFS_MIN_RTEXTSIZE)
 844		return -EINVAL;
 845
 846	/* Unsupported realtime features. */
 847	if (xfs_has_rmapbt(mp) || xfs_has_reflink(mp) || xfs_has_quota(mp))
 848		return -EOPNOTSUPP;
 849
 850	nrblocks = in->newblocks;
 851	error = xfs_sb_validate_fsb_count(sbp, nrblocks);
 852	if (error)
 853		return error;
 854	/*
 855	 * Read in the last block of the device, make sure it exists.
 856	 */
 857	error = xfs_buf_read_uncached(mp->m_rtdev_targp,
 858				XFS_FSB_TO_BB(mp, nrblocks - 1),
 859				XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
 860	if (error)
 861		return error;
 862	xfs_buf_relse(bp);
 863
 864	/*
 865	 * Calculate new parameters.  These are the final values to be reached.
 866	 */
 867	nrextents = nrblocks;
 868	do_div(nrextents, in->extsize);
 869	if (!xfs_validate_rtextents(nrextents))
 870		return -EINVAL;
 871	nrbmblocks = xfs_rtbitmap_blockcount(mp, nrextents);
 872	nrextslog = xfs_compute_rextslog(nrextents);
 873	nrsumlevels = nrextslog + 1;
 874	nrsumblocks = xfs_rtsummary_blockcount(mp, nrsumlevels, nrbmblocks);
 875	nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
 876	/*
 877	 * New summary size can't be more than half the size of
 878	 * the log.  This prevents us from getting a log overflow,
 879	 * since we'll log basically the whole summary file at once.
 880	 */
 881	if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
 882		return -EINVAL;
 883	/*
 884	 * Get the old block counts for bitmap and summary inodes.
 885	 * These can't change since other growfs callers are locked out.
 886	 */
 887	rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_disk_size);
 888	rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_disk_size);
 889	/*
 890	 * Allocate space to the bitmap and summary files, as necessary.
 891	 */
 892	error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks, mp->m_rbmip);
 893	if (error)
 894		return error;
 895	error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
 896	if (error)
 897		return error;
 898
 899	rsum_cache = mp->m_rsum_cache;
 900	if (nrbmblocks != sbp->sb_rbmblocks)
 901		xfs_alloc_rsum_cache(mp, nrbmblocks);
 902
 903	/*
 904	 * Allocate a new (fake) mount/sb.
 905	 */
 906	nmp = kmem_alloc(sizeof(*nmp), 0);
 907	/*
 908	 * Loop over the bitmap blocks.
 909	 * We will do everything one bitmap block at a time.
 910	 * Skip the current block if it is exactly full.
 911	 * This also deals with the case where there were no rtextents before.
 912	 */
 913	for (bmbno = sbp->sb_rbmblocks -
 914		     ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
 915	     bmbno < nrbmblocks;
 916	     bmbno++) {
 917		struct xfs_rtalloc_args	args = {
 918			.mp		= mp,
 919		};
 920		struct xfs_rtalloc_args	nargs = {
 921			.mp		= nmp,
 922		};
 923		struct xfs_trans	*tp;
 924		xfs_rfsblock_t		nrblocks_step;
 925
 926		*nmp = *mp;
 927		nsbp = &nmp->m_sb;
 928		/*
 929		 * Calculate new sb and mount fields for this round.
 930		 */
 931		nsbp->sb_rextsize = in->extsize;
 932		nmp->m_rtxblklog = -1; /* don't use shift or masking */
 933		nsbp->sb_rbmblocks = bmbno + 1;
 934		nrblocks_step = (bmbno + 1) * NBBY * nsbp->sb_blocksize *
 935				nsbp->sb_rextsize;
 936		nsbp->sb_rblocks = min(nrblocks, nrblocks_step);
 937		nsbp->sb_rextents = xfs_rtb_to_rtx(nmp, nsbp->sb_rblocks);
 938		ASSERT(nsbp->sb_rextents != 0);
 939		nsbp->sb_rextslog = xfs_compute_rextslog(nsbp->sb_rextents);
 940		nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
 941		nrsumblocks = xfs_rtsummary_blockcount(mp, nrsumlevels,
 942				nsbp->sb_rbmblocks);
 943		nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
 944		/* recompute growfsrt reservation from new rsumsize */
 945		xfs_trans_resv_calc(nmp, &nmp->m_resv);
 946
 947		/*
 948		 * Start a transaction, get the log reservation.
 949		 */
 950		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtfree, 0, 0, 0,
 951				&tp);
 952		if (error)
 953			break;
 954		args.tp = tp;
 955		nargs.tp = tp;
 956
 957		/*
 958		 * Lock out other callers by grabbing the bitmap inode lock.
 959		 */
 960		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
 961		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
 962		/*
 963		 * Update the bitmap inode's size ondisk and incore.  We need
 964		 * to update the incore size so that inode inactivation won't
 965		 * punch what it thinks are "posteof" blocks.
 966		 */
 967		mp->m_rbmip->i_disk_size =
 968			nsbp->sb_rbmblocks * nsbp->sb_blocksize;
 969		i_size_write(VFS_I(mp->m_rbmip), mp->m_rbmip->i_disk_size);
 970		xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
 971		/*
 972		 * Get the summary inode into the transaction.
 973		 */
 974		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
 975		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
 976		/*
 977		 * Update the summary inode's size.  We need to update the
 978		 * incore size so that inode inactivation won't punch what it
 979		 * thinks are "posteof" blocks.
 980		 */
 981		mp->m_rsumip->i_disk_size = nmp->m_rsumsize;
 982		i_size_write(VFS_I(mp->m_rsumip), mp->m_rsumip->i_disk_size);
 983		xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
 984		/*
 985		 * Copy summary data from old to new sizes.
 986		 * Do this when the real size (not block-aligned) changes.
 987		 */
 988		if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
 989		    mp->m_rsumlevels != nmp->m_rsumlevels) {
 990			error = xfs_rtcopy_summary(&args, &nargs);
 991			if (error)
 992				goto error_cancel;
 993		}
 994		/*
 995		 * Update superblock fields.
 996		 */
 997		if (nsbp->sb_rextsize != sbp->sb_rextsize)
 998			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
 999				nsbp->sb_rextsize - sbp->sb_rextsize);
1000		if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
1001			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
1002				nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
1003		if (nsbp->sb_rblocks != sbp->sb_rblocks)
1004			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
1005				nsbp->sb_rblocks - sbp->sb_rblocks);
1006		if (nsbp->sb_rextents != sbp->sb_rextents)
1007			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
1008				nsbp->sb_rextents - sbp->sb_rextents);
1009		if (nsbp->sb_rextslog != sbp->sb_rextslog)
1010			xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
1011				nsbp->sb_rextslog - sbp->sb_rextslog);
1012		/*
1013		 * Free new extent.
1014		 */
1015		error = xfs_rtfree_range(&nargs, sbp->sb_rextents,
1016				nsbp->sb_rextents - sbp->sb_rextents);
1017		xfs_rtbuf_cache_relse(&nargs);
1018		if (error) {
1019error_cancel:
1020			xfs_trans_cancel(tp);
1021			break;
1022		}
1023		/*
1024		 * Mark more blocks free in the superblock.
1025		 */
1026		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
1027			nsbp->sb_rextents - sbp->sb_rextents);
1028		/*
1029		 * Update mp values into the real mp structure.
1030		 */
1031		mp->m_rsumlevels = nrsumlevels;
1032		mp->m_rsumsize = nrsumsize;
1033		/* recompute growfsrt reservation from new rsumsize */
1034		xfs_trans_resv_calc(mp, &mp->m_resv);
1035
1036		error = xfs_trans_commit(tp);
1037		if (error)
1038			break;
1039
1040		/* Ensure the mount RT feature flag is now set. */
1041		mp->m_features |= XFS_FEAT_REALTIME;
1042	}
1043	if (error)
1044		goto out_free;
1045
1046	/* Update secondary superblocks now the physical grow has completed */
1047	error = xfs_update_secondary_sbs(mp);
1048
1049out_free:
1050	/*
1051	 * Free the fake mp structure.
1052	 */
1053	kmem_free(nmp);
1054
1055	/*
1056	 * If we had to allocate a new rsum_cache, we either need to free the
1057	 * old one (if we succeeded) or free the new one and restore the old one
1058	 * (if there was an error).
1059	 */
1060	if (rsum_cache != mp->m_rsum_cache) {
1061		if (error) {
1062			kmem_free(mp->m_rsum_cache);
1063			mp->m_rsum_cache = rsum_cache;
1064		} else {
1065			kmem_free(rsum_cache);
1066		}
1067	}
1068
1069	return error;
1070}
1071
1072/*
1073 * Initialize realtime fields in the mount structure.
1074 */
1075int				/* error */
1076xfs_rtmount_init(
1077	struct xfs_mount	*mp)	/* file system mount structure */
1078{
1079	struct xfs_buf		*bp;	/* buffer for last block of subvolume */
1080	struct xfs_sb		*sbp;	/* filesystem superblock copy in mount */
1081	xfs_daddr_t		d;	/* address of last block of subvolume */
1082	unsigned int		rsumblocks;
1083	int			error;
1084
1085	sbp = &mp->m_sb;
1086	if (sbp->sb_rblocks == 0)
1087		return 0;
1088	if (mp->m_rtdev_targp == NULL) {
1089		xfs_warn(mp,
1090	"Filesystem has a realtime volume, use rtdev=device option");
1091		return -ENODEV;
1092	}
1093	mp->m_rsumlevels = sbp->sb_rextslog + 1;
1094	rsumblocks = xfs_rtsummary_blockcount(mp, mp->m_rsumlevels,
1095			mp->m_sb.sb_rbmblocks);
1096	mp->m_rsumsize = XFS_FSB_TO_B(mp, rsumblocks);
1097	mp->m_rbmip = mp->m_rsumip = NULL;
1098	/*
1099	 * Check that the realtime section is an ok size.
1100	 */
1101	d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
1102	if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
1103		xfs_warn(mp, "realtime mount -- %llu != %llu",
1104			(unsigned long long) XFS_BB_TO_FSB(mp, d),
1105			(unsigned long long) mp->m_sb.sb_rblocks);
1106		return -EFBIG;
1107	}
1108	error = xfs_buf_read_uncached(mp->m_rtdev_targp,
1109					d - XFS_FSB_TO_BB(mp, 1),
1110					XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
1111	if (error) {
1112		xfs_warn(mp, "realtime device size check failed");
1113		return error;
1114	}
1115	xfs_buf_relse(bp);
1116	return 0;
1117}
1118
1119static int
1120xfs_rtalloc_count_frextent(
1121	struct xfs_mount		*mp,
1122	struct xfs_trans		*tp,
1123	const struct xfs_rtalloc_rec	*rec,
1124	void				*priv)
1125{
1126	uint64_t			*valp = priv;
1127
1128	*valp += rec->ar_extcount;
1129	return 0;
1130}
1131
1132/*
1133 * Reinitialize the number of free realtime extents from the realtime bitmap.
1134 * Callers must ensure that there is no other activity in the filesystem.
1135 */
1136int
1137xfs_rtalloc_reinit_frextents(
1138	struct xfs_mount	*mp)
1139{
1140	uint64_t		val = 0;
1141	int			error;
1142
1143	xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
1144	error = xfs_rtalloc_query_all(mp, NULL, xfs_rtalloc_count_frextent,
1145			&val);
1146	xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
1147	if (error)
1148		return error;
1149
1150	spin_lock(&mp->m_sb_lock);
1151	mp->m_sb.sb_frextents = val;
1152	spin_unlock(&mp->m_sb_lock);
1153	percpu_counter_set(&mp->m_frextents, mp->m_sb.sb_frextents);
1154	return 0;
1155}
1156
1157/*
1158 * Read in the bmbt of an rt metadata inode so that we never have to load them
1159 * at runtime.  This enables the use of shared ILOCKs for rtbitmap scans.  Use
1160 * an empty transaction to avoid deadlocking on loops in the bmbt.
1161 */
1162static inline int
1163xfs_rtmount_iread_extents(
1164	struct xfs_inode	*ip,
1165	unsigned int		lock_class)
1166{
1167	struct xfs_trans	*tp;
1168	int			error;
1169
1170	error = xfs_trans_alloc_empty(ip->i_mount, &tp);
1171	if (error)
1172		return error;
1173
1174	xfs_ilock(ip, XFS_ILOCK_EXCL | lock_class);
1175
1176	error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);
1177	if (error)
1178		goto out_unlock;
1179
1180	if (xfs_inode_has_attr_fork(ip)) {
1181		error = xfs_iread_extents(tp, ip, XFS_ATTR_FORK);
1182		if (error)
1183			goto out_unlock;
1184	}
1185
1186out_unlock:
1187	xfs_iunlock(ip, XFS_ILOCK_EXCL | lock_class);
1188	xfs_trans_cancel(tp);
1189	return error;
1190}
1191
1192/*
1193 * Get the bitmap and summary inodes and the summary cache into the mount
1194 * structure at mount time.
1195 */
1196int					/* error */
1197xfs_rtmount_inodes(
1198	xfs_mount_t	*mp)		/* file system mount structure */
1199{
1200	int		error;		/* error return value */
1201	xfs_sb_t	*sbp;
1202
1203	sbp = &mp->m_sb;
1204	error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
 
 
1205	if (error)
1206		return error;
1207	ASSERT(mp->m_rbmip != NULL);
1208
1209	error = xfs_rtmount_iread_extents(mp->m_rbmip, XFS_ILOCK_RTBITMAP);
1210	if (error)
1211		goto out_rele_bitmap;
1212
1213	error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
 
 
1214	if (error)
1215		goto out_rele_bitmap;
1216	ASSERT(mp->m_rsumip != NULL);
1217
1218	error = xfs_rtmount_iread_extents(mp->m_rsumip, XFS_ILOCK_RTSUM);
1219	if (error)
1220		goto out_rele_summary;
1221
1222	xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks);
1223	return 0;
1224
1225out_rele_summary:
1226	xfs_irele(mp->m_rsumip);
1227out_rele_bitmap:
1228	xfs_irele(mp->m_rbmip);
1229	return error;
1230}
1231
1232void
1233xfs_rtunmount_inodes(
1234	struct xfs_mount	*mp)
1235{
1236	kmem_free(mp->m_rsum_cache);
1237	if (mp->m_rbmip)
1238		xfs_irele(mp->m_rbmip);
1239	if (mp->m_rsumip)
1240		xfs_irele(mp->m_rsumip);
1241}
1242
1243/*
1244 * Pick an extent for allocation at the start of a new realtime file.
1245 * Use the sequence number stored in the atime field of the bitmap inode.
1246 * Translate this to a fraction of the rtextents, and return the product
1247 * of rtextents and the fraction.
1248 * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
1249 */
1250static int
1251xfs_rtpick_extent(
1252	xfs_mount_t		*mp,		/* file system mount point */
1253	xfs_trans_t		*tp,		/* transaction pointer */
1254	xfs_rtxlen_t		len,		/* allocation length (rtextents) */
1255	xfs_rtxnum_t		*pick)		/* result rt extent */
1256{
1257	xfs_rtxnum_t		b;		/* result rtext */
1258	int			log2;		/* log of sequence number */
1259	uint64_t		resid;		/* residual after log removed */
1260	uint64_t		seq;		/* sequence number of file creation */
1261	struct timespec64	ts;		/* timespec in inode */
1262
1263	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
1264
1265	ts = inode_get_atime(VFS_I(mp->m_rbmip));
1266	if (!(mp->m_rbmip->i_diflags & XFS_DIFLAG_NEWRTBM)) {
1267		mp->m_rbmip->i_diflags |= XFS_DIFLAG_NEWRTBM;
1268		seq = 0;
1269	} else {
1270		seq = ts.tv_sec;
1271	}
1272	if ((log2 = xfs_highbit64(seq)) == -1)
1273		b = 0;
1274	else {
1275		resid = seq - (1ULL << log2);
1276		b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
1277		    (log2 + 1);
1278		if (b >= mp->m_sb.sb_rextents)
1279			div64_u64_rem(b, mp->m_sb.sb_rextents, &b);
1280		if (b + len > mp->m_sb.sb_rextents)
1281			b = mp->m_sb.sb_rextents - len;
1282	}
1283	ts.tv_sec = seq + 1;
1284	inode_set_atime_to_ts(VFS_I(mp->m_rbmip), ts);
1285	xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1286	*pick = b;
1287	return 0;
1288}
1289
1290static void
1291xfs_rtalloc_align_minmax(
1292	xfs_rtxlen_t		*raminlen,
1293	xfs_rtxlen_t		*ramaxlen,
1294	xfs_rtxlen_t		*prod)
1295{
1296	xfs_rtxlen_t		newmaxlen = *ramaxlen;
1297	xfs_rtxlen_t		newminlen = *raminlen;
1298	xfs_rtxlen_t		slack;
1299
1300	slack = newmaxlen % *prod;
1301	if (slack)
1302		newmaxlen -= slack;
1303	slack = newminlen % *prod;
1304	if (slack)
1305		newminlen += *prod - slack;
1306
1307	/*
1308	 * If adjusting for extent size hint alignment produces an invalid
1309	 * min/max len combination, go ahead without it.
1310	 */
1311	if (newmaxlen < newminlen) {
1312		*prod = 1;
1313		return;
1314	}
1315	*ramaxlen = newmaxlen;
1316	*raminlen = newminlen;
1317}
1318
1319int
1320xfs_bmap_rtalloc(
1321	struct xfs_bmalloca	*ap)
1322{
1323	struct xfs_mount	*mp = ap->ip->i_mount;
1324	xfs_fileoff_t		orig_offset = ap->offset;
1325	xfs_rtxnum_t		start;	   /* allocation hint rtextent no */
1326	xfs_rtxnum_t		rtx;	   /* actually allocated rtextent no */
1327	xfs_rtxlen_t		prod = 0;  /* product factor for allocators */
1328	xfs_extlen_t		mod = 0;   /* product factor for allocators */
1329	xfs_rtxlen_t		ralen = 0; /* realtime allocation length */
1330	xfs_extlen_t		align;     /* minimum allocation alignment */
1331	xfs_extlen_t		orig_length = ap->length;
1332	xfs_extlen_t		minlen = mp->m_sb.sb_rextsize;
1333	xfs_rtxlen_t		raminlen;
1334	bool			rtlocked = false;
1335	bool			ignore_locality = false;
1336	struct xfs_rtalloc_args	args = {
1337		.mp		= mp,
1338		.tp		= ap->tp,
1339	};
1340	int			error;
1341
1342	align = xfs_get_extsz_hint(ap->ip);
1343retry:
1344	error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
1345					align, 1, ap->eof, 0,
1346					ap->conv, &ap->offset, &ap->length);
1347	if (error)
1348		return error;
1349	ASSERT(ap->length);
1350	ASSERT(xfs_extlen_to_rtxmod(mp, ap->length) == 0);
1351
1352	/*
1353	 * If we shifted the file offset downward to satisfy an extent size
1354	 * hint, increase minlen by that amount so that the allocator won't
1355	 * give us an allocation that's too short to cover at least one of the
1356	 * blocks that the caller asked for.
1357	 */
1358	if (ap->offset != orig_offset)
1359		minlen += orig_offset - ap->offset;
1360
1361	/*
1362	 * Set ralen to be the actual requested length in rtextents.
1363	 *
1364	 * If the old value was close enough to XFS_BMBT_MAX_EXTLEN that
1365	 * we rounded up to it, cut it back so it's valid again.
1366	 * Note that if it's a really large request (bigger than
1367	 * XFS_BMBT_MAX_EXTLEN), we don't hear about that number, and can't
1368	 * adjust the starting point to match it.
1369	 */
1370	ralen = xfs_extlen_to_rtxlen(mp, min(ap->length, XFS_MAX_BMBT_EXTLEN));
1371	raminlen = max_t(xfs_rtxlen_t, 1, xfs_extlen_to_rtxlen(mp, minlen));
1372	ASSERT(raminlen > 0);
1373	ASSERT(raminlen <= ralen);
1374
1375	/*
1376	 * Lock out modifications to both the RT bitmap and summary inodes
1377	 */
1378	if (!rtlocked) {
1379		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
1380		xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
1381		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
1382		xfs_trans_ijoin(ap->tp, mp->m_rsumip, XFS_ILOCK_EXCL);
1383		rtlocked = true;
1384	}
1385
1386	if (ignore_locality) {
1387		start = 0;
1388	} else if (xfs_bmap_adjacent(ap)) {
1389		start = xfs_rtb_to_rtx(mp, ap->blkno);
1390	} else if (ap->eof && ap->offset == 0) {
1391		/*
1392		 * If it's an allocation to an empty file at offset 0, pick an
1393		 * extent that will space things out in the rt area.
1394		 */
1395		error = xfs_rtpick_extent(mp, ap->tp, ralen, &start);
1396		if (error)
1397			return error;
1398	} else {
1399		start = 0;
1400	}
1401
1402	/*
1403	 * Only bother calculating a real prod factor if offset & length are
1404	 * perfectly aligned, otherwise it will just get us in trouble.
1405	 */
1406	div_u64_rem(ap->offset, align, &mod);
1407	if (mod || ap->length % align) {
1408		prod = 1;
1409	} else {
1410		prod = xfs_extlen_to_rtxlen(mp, align);
1411		if (prod > 1)
1412			xfs_rtalloc_align_minmax(&raminlen, &ralen, &prod);
1413	}
1414
1415	if (start) {
1416		error = xfs_rtallocate_extent_near(&args, start, raminlen,
1417				ralen, &ralen, prod, &rtx);
1418	} else {
1419		error = xfs_rtallocate_extent_size(&args, raminlen,
1420				ralen, &ralen, prod, &rtx);
1421	}
1422	xfs_rtbuf_cache_relse(&args);
1423
1424	if (error == -ENOSPC) {
1425		if (align > mp->m_sb.sb_rextsize) {
1426			/*
1427			 * We previously enlarged the request length to try to
1428			 * satisfy an extent size hint.  The allocator didn't
1429			 * return anything, so reset the parameters to the
1430			 * original values and try again without alignment
1431			 * criteria.
1432			 */
1433			ap->offset = orig_offset;
1434			ap->length = orig_length;
1435			minlen = align = mp->m_sb.sb_rextsize;
1436			goto retry;
1437		}
1438
1439		if (!ignore_locality && start != 0) {
1440			/*
1441			 * If we can't allocate near a specific rt extent, try
1442			 * again without locality criteria.
1443			 */
1444			ignore_locality = true;
1445			goto retry;
1446		}
1447
1448		ap->blkno = NULLFSBLOCK;
1449		ap->length = 0;
1450		return 0;
1451	}
1452	if (error)
1453		return error;
1454
1455	xfs_trans_mod_sb(ap->tp, ap->wasdel ?
1456			XFS_TRANS_SB_RES_FREXTENTS : XFS_TRANS_SB_FREXTENTS,
1457			-(long)ralen);
1458	ap->blkno = xfs_rtx_to_rtb(mp, rtx);
1459	ap->length = xfs_rtxlen_to_extlen(mp, ralen);
1460	xfs_bmap_alloc_account(ap);
1461	return 0;
1462}