1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   4 * Copyright (c) 2012 Red Hat, Inc.
   5 * All Rights Reserved.
   6 */
   7#include "xfs.h"
   8#include "xfs_fs.h"
   9#include "xfs_shared.h"
  10#include "xfs_format.h"
  11#include "xfs_log_format.h"
  12#include "xfs_trans_resv.h"
  13#include "xfs_bit.h"
  14#include "xfs_mount.h"
  15#include "xfs_defer.h"
  16#include "xfs_inode.h"
  17#include "xfs_btree.h"
  18#include "xfs_trans.h"
  19#include "xfs_alloc.h"
  20#include "xfs_bmap.h"
  21#include "xfs_bmap_util.h"
  22#include "xfs_bmap_btree.h"
  23#include "xfs_rtalloc.h"
  24#include "xfs_error.h"
  25#include "xfs_quota.h"
  26#include "xfs_trans_space.h"
  27#include "xfs_trace.h"
  28#include "xfs_icache.h"
  29#include "xfs_iomap.h"
  30#include "xfs_reflink.h"
  31#include "xfs_rtbitmap.h"
 
  32
  33/* Kernel only BMAP related definitions and functions */
  34
  35/*
  36 * Convert the given file system block to a disk block.  We have to treat it
  37 * differently based on whether the file is a real time file or not, because the
  38 * bmap code does.
  39 */
  40xfs_daddr_t
  41xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb)
  42{
  43	if (XFS_IS_REALTIME_INODE(ip))
  44		return XFS_FSB_TO_BB(ip->i_mount, fsb);
  45	return XFS_FSB_TO_DADDR(ip->i_mount, fsb);
  46}
  47
  48/*
  49 * Routine to zero an extent on disk allocated to the specific inode.
  50 *
  51 * The VFS functions take a linearised filesystem block offset, so we have to
  52 * convert the sparse xfs fsb to the right format first.
  53 * VFS types are real funky, too.
  54 */
  55int
  56xfs_zero_extent(
  57	struct xfs_inode	*ip,
  58	xfs_fsblock_t		start_fsb,
  59	xfs_off_t		count_fsb)
  60{
  61	struct xfs_mount	*mp = ip->i_mount;
  62	struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
  63	xfs_daddr_t		sector = xfs_fsb_to_db(ip, start_fsb);
  64	sector_t		block = XFS_BB_TO_FSBT(mp, sector);
  65
  66	return blkdev_issue_zeroout(target->bt_bdev,
  67		block << (mp->m_super->s_blocksize_bits - 9),
  68		count_fsb << (mp->m_super->s_blocksize_bits - 9),
  69		GFP_KERNEL, 0);
  70}
  71
  72/*
  73 * Extent tree block counting routines.
  74 */
  75
  76/*
  77 * Count leaf blocks given a range of extent records.  Delayed allocation
  78 * extents are not counted towards the totals.
  79 */
  80xfs_extnum_t
  81xfs_bmap_count_leaves(
  82	struct xfs_ifork	*ifp,
  83	xfs_filblks_t		*count)
  84{
  85	struct xfs_iext_cursor	icur;
  86	struct xfs_bmbt_irec	got;
  87	xfs_extnum_t		numrecs = 0;
  88
  89	for_each_xfs_iext(ifp, &icur, &got) {
  90		if (!isnullstartblock(got.br_startblock)) {
  91			*count += got.br_blockcount;
  92			numrecs++;
  93		}
  94	}
  95
  96	return numrecs;
  97}
  98
  99/*
 100 * Count fsblocks of the given fork.  Delayed allocation extents are
 101 * not counted towards the totals.
 102 */
 103int
 104xfs_bmap_count_blocks(
 105	struct xfs_trans	*tp,
 106	struct xfs_inode	*ip,
 107	int			whichfork,
 108	xfs_extnum_t		*nextents,
 109	xfs_filblks_t		*count)
 110{
 111	struct xfs_mount	*mp = ip->i_mount;
 112	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
 113	struct xfs_btree_cur	*cur;
 114	xfs_extlen_t		btblocks = 0;
 115	int			error;
 116
 117	*nextents = 0;
 118	*count = 0;
 119
 120	if (!ifp)
 121		return 0;
 122
 123	switch (ifp->if_format) {
 124	case XFS_DINODE_FMT_BTREE:
 125		error = xfs_iread_extents(tp, ip, whichfork);
 126		if (error)
 127			return error;
 128
 129		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
 130		error = xfs_btree_count_blocks(cur, &btblocks);
 131		xfs_btree_del_cursor(cur, error);
 132		if (error)
 133			return error;
 134
 135		/*
 136		 * xfs_btree_count_blocks includes the root block contained in
 137		 * the inode fork in @btblocks, so subtract one because we're
 138		 * only interested in allocated disk blocks.
 139		 */
 140		*count += btblocks - 1;
 141
 142		fallthrough;
 143	case XFS_DINODE_FMT_EXTENTS:
 144		*nextents = xfs_bmap_count_leaves(ifp, count);
 145		break;
 146	}
 147
 148	return 0;
 149}
 150
 151static int
 152xfs_getbmap_report_one(
 153	struct xfs_inode	*ip,
 154	struct getbmapx		*bmv,
 155	struct kgetbmap		*out,
 156	int64_t			bmv_end,
 157	struct xfs_bmbt_irec	*got)
 158{
 159	struct kgetbmap		*p = out + bmv->bmv_entries;
 160	bool			shared = false;
 161	int			error;
 162
 163	error = xfs_reflink_trim_around_shared(ip, got, &shared);
 164	if (error)
 165		return error;
 166
 167	if (isnullstartblock(got->br_startblock) ||
 168	    got->br_startblock == DELAYSTARTBLOCK) {
 169		/*
 170		 * Take the flush completion as being a point-in-time snapshot
 171		 * where there are no delalloc extents, and if any new ones
 172		 * have been created racily, just skip them as being 'after'
 173		 * the flush and so don't get reported.
 174		 */
 175		if (!(bmv->bmv_iflags & BMV_IF_DELALLOC))
 176			return 0;
 177
 178		p->bmv_oflags |= BMV_OF_DELALLOC;
 179		p->bmv_block = -2;
 180	} else {
 181		p->bmv_block = xfs_fsb_to_db(ip, got->br_startblock);
 182	}
 183
 184	if (got->br_state == XFS_EXT_UNWRITTEN &&
 185	    (bmv->bmv_iflags & BMV_IF_PREALLOC))
 186		p->bmv_oflags |= BMV_OF_PREALLOC;
 187
 188	if (shared)
 189		p->bmv_oflags |= BMV_OF_SHARED;
 190
 191	p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, got->br_startoff);
 192	p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, got->br_blockcount);
 193
 194	bmv->bmv_offset = p->bmv_offset + p->bmv_length;
 195	bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
 196	bmv->bmv_entries++;
 197	return 0;
 198}
 199
 200static void
 201xfs_getbmap_report_hole(
 202	struct xfs_inode	*ip,
 203	struct getbmapx		*bmv,
 204	struct kgetbmap		*out,
 205	int64_t			bmv_end,
 206	xfs_fileoff_t		bno,
 207	xfs_fileoff_t		end)
 208{
 209	struct kgetbmap		*p = out + bmv->bmv_entries;
 210
 211	if (bmv->bmv_iflags & BMV_IF_NO_HOLES)
 212		return;
 213
 214	p->bmv_block = -1;
 215	p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, bno);
 216	p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, end - bno);
 217
 218	bmv->bmv_offset = p->bmv_offset + p->bmv_length;
 219	bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
 220	bmv->bmv_entries++;
 221}
 222
 223static inline bool
 224xfs_getbmap_full(
 225	struct getbmapx		*bmv)
 226{
 227	return bmv->bmv_length == 0 || bmv->bmv_entries >= bmv->bmv_count - 1;
 228}
 229
 230static bool
 231xfs_getbmap_next_rec(
 232	struct xfs_bmbt_irec	*rec,
 233	xfs_fileoff_t		total_end)
 234{
 235	xfs_fileoff_t		end = rec->br_startoff + rec->br_blockcount;
 236
 237	if (end == total_end)
 238		return false;
 239
 240	rec->br_startoff += rec->br_blockcount;
 241	if (!isnullstartblock(rec->br_startblock) &&
 242	    rec->br_startblock != DELAYSTARTBLOCK)
 243		rec->br_startblock += rec->br_blockcount;
 244	rec->br_blockcount = total_end - end;
 245	return true;
 246}
 247
 248/*
 249 * Get inode's extents as described in bmv, and format for output.
 250 * Calls formatter to fill the user's buffer until all extents
 251 * are mapped, until the passed-in bmv->bmv_count slots have
 252 * been filled, or until the formatter short-circuits the loop,
 253 * if it is tracking filled-in extents on its own.
 254 */
 255int						/* error code */
 256xfs_getbmap(
 257	struct xfs_inode	*ip,
 258	struct getbmapx		*bmv,		/* user bmap structure */
 259	struct kgetbmap		*out)
 260{
 261	struct xfs_mount	*mp = ip->i_mount;
 262	int			iflags = bmv->bmv_iflags;
 263	int			whichfork, lock, error = 0;
 264	int64_t			bmv_end, max_len;
 265	xfs_fileoff_t		bno, first_bno;
 266	struct xfs_ifork	*ifp;
 267	struct xfs_bmbt_irec	got, rec;
 268	xfs_filblks_t		len;
 269	struct xfs_iext_cursor	icur;
 270
 271	if (bmv->bmv_iflags & ~BMV_IF_VALID)
 272		return -EINVAL;
 273#ifndef DEBUG
 274	/* Only allow CoW fork queries if we're debugging. */
 275	if (iflags & BMV_IF_COWFORK)
 276		return -EINVAL;
 277#endif
 278	if ((iflags & BMV_IF_ATTRFORK) && (iflags & BMV_IF_COWFORK))
 279		return -EINVAL;
 280
 281	if (bmv->bmv_length < -1)
 282		return -EINVAL;
 283	bmv->bmv_entries = 0;
 284	if (bmv->bmv_length == 0)
 285		return 0;
 286
 287	if (iflags & BMV_IF_ATTRFORK)
 288		whichfork = XFS_ATTR_FORK;
 289	else if (iflags & BMV_IF_COWFORK)
 290		whichfork = XFS_COW_FORK;
 291	else
 292		whichfork = XFS_DATA_FORK;
 293
 294	xfs_ilock(ip, XFS_IOLOCK_SHARED);
 295	switch (whichfork) {
 296	case XFS_ATTR_FORK:
 297		lock = xfs_ilock_attr_map_shared(ip);
 298		if (!xfs_inode_has_attr_fork(ip))
 299			goto out_unlock_ilock;
 300
 301		max_len = 1LL << 32;
 302		break;
 303	case XFS_COW_FORK:
 304		lock = XFS_ILOCK_SHARED;
 305		xfs_ilock(ip, lock);
 306
 307		/* No CoW fork? Just return */
 308		if (!xfs_ifork_ptr(ip, whichfork))
 309			goto out_unlock_ilock;
 310
 311		if (xfs_get_cowextsz_hint(ip))
 312			max_len = mp->m_super->s_maxbytes;
 313		else
 314			max_len = XFS_ISIZE(ip);
 315		break;
 316	case XFS_DATA_FORK:
 317		if (!(iflags & BMV_IF_DELALLOC) &&
 318		    (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_disk_size)) {
 319			error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
 320			if (error)
 321				goto out_unlock_iolock;
 322
 323			/*
 324			 * Even after flushing the inode, there can still be
 325			 * delalloc blocks on the inode beyond EOF due to
 326			 * speculative preallocation.  These are not removed
 327			 * until the release function is called or the inode
 328			 * is inactivated.  Hence we cannot assert here that
 329			 * ip->i_delayed_blks == 0.
 330			 */
 331		}
 332
 333		if (xfs_get_extsz_hint(ip) ||
 334		    (ip->i_diflags &
 335		     (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))
 336			max_len = mp->m_super->s_maxbytes;
 337		else
 338			max_len = XFS_ISIZE(ip);
 339
 340		lock = xfs_ilock_data_map_shared(ip);
 341		break;
 342	}
 343
 344	ifp = xfs_ifork_ptr(ip, whichfork);
 345
 346	switch (ifp->if_format) {
 347	case XFS_DINODE_FMT_EXTENTS:
 348	case XFS_DINODE_FMT_BTREE:
 349		break;
 350	case XFS_DINODE_FMT_LOCAL:
 351		/* Local format inode forks report no extents. */
 352		goto out_unlock_ilock;
 353	default:
 354		error = -EINVAL;
 355		goto out_unlock_ilock;
 356	}
 357
 358	if (bmv->bmv_length == -1) {
 359		max_len = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, max_len));
 360		bmv->bmv_length = max(0LL, max_len - bmv->bmv_offset);
 361	}
 362
 363	bmv_end = bmv->bmv_offset + bmv->bmv_length;
 364
 365	first_bno = bno = XFS_BB_TO_FSBT(mp, bmv->bmv_offset);
 366	len = XFS_BB_TO_FSB(mp, bmv->bmv_length);
 367
 368	error = xfs_iread_extents(NULL, ip, whichfork);
 369	if (error)
 370		goto out_unlock_ilock;
 371
 372	if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
 373		/*
 374		 * Report a whole-file hole if the delalloc flag is set to
 375		 * stay compatible with the old implementation.
 376		 */
 377		if (iflags & BMV_IF_DELALLOC)
 378			xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
 379					XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
 380		goto out_unlock_ilock;
 381	}
 382
 383	while (!xfs_getbmap_full(bmv)) {
 384		xfs_trim_extent(&got, first_bno, len);
 385
 386		/*
 387		 * Report an entry for a hole if this extent doesn't directly
 388		 * follow the previous one.
 389		 */
 390		if (got.br_startoff > bno) {
 391			xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
 392					got.br_startoff);
 393			if (xfs_getbmap_full(bmv))
 394				break;
 395		}
 396
 397		/*
 398		 * In order to report shared extents accurately, we report each
 399		 * distinct shared / unshared part of a single bmbt record with
 400		 * an individual getbmapx record.
 401		 */
 402		bno = got.br_startoff + got.br_blockcount;
 403		rec = got;
 404		do {
 405			error = xfs_getbmap_report_one(ip, bmv, out, bmv_end,
 406					&rec);
 407			if (error || xfs_getbmap_full(bmv))
 408				goto out_unlock_ilock;
 409		} while (xfs_getbmap_next_rec(&rec, bno));
 410
 411		if (!xfs_iext_next_extent(ifp, &icur, &got)) {
 412			xfs_fileoff_t	end = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
 413
 414			if (bmv->bmv_entries > 0)
 415				out[bmv->bmv_entries - 1].bmv_oflags |=
 416								BMV_OF_LAST;
 417
 418			if (whichfork != XFS_ATTR_FORK && bno < end &&
 419			    !xfs_getbmap_full(bmv)) {
 420				xfs_getbmap_report_hole(ip, bmv, out, bmv_end,
 421						bno, end);
 422			}
 423			break;
 424		}
 425
 426		if (bno >= first_bno + len)
 427			break;
 428	}
 429
 430out_unlock_ilock:
 431	xfs_iunlock(ip, lock);
 432out_unlock_iolock:
 433	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
 434	return error;
 435}
 436
 437/*
 438 * Dead simple method of punching delalyed allocation blocks from a range in
 439 * the inode.  This will always punch out both the start and end blocks, even
 440 * if the ranges only partially overlap them, so it is up to the caller to
 441 * ensure that partial blocks are not passed in.
 442 */
 443int
 444xfs_bmap_punch_delalloc_range(
 445	struct xfs_inode	*ip,
 
 446	xfs_off_t		start_byte,
 447	xfs_off_t		end_byte)
 448{
 449	struct xfs_mount	*mp = ip->i_mount;
 450	struct xfs_ifork	*ifp = &ip->i_df;
 451	xfs_fileoff_t		start_fsb = XFS_B_TO_FSBT(mp, start_byte);
 452	xfs_fileoff_t		end_fsb = XFS_B_TO_FSB(mp, end_byte);
 453	struct xfs_bmbt_irec	got, del;
 454	struct xfs_iext_cursor	icur;
 455	int			error = 0;
 456
 457	ASSERT(!xfs_need_iread_extents(ifp));
 458
 459	xfs_ilock(ip, XFS_ILOCK_EXCL);
 460	if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got))
 461		goto out_unlock;
 462
 463	while (got.br_startoff + got.br_blockcount > start_fsb) {
 464		del = got;
 465		xfs_trim_extent(&del, start_fsb, end_fsb - start_fsb);
 466
 467		/*
 468		 * A delete can push the cursor forward. Step back to the
 469		 * previous extent on non-delalloc or extents outside the
 470		 * target range.
 471		 */
 472		if (!del.br_blockcount ||
 473		    !isnullstartblock(del.br_startblock)) {
 474			if (!xfs_iext_prev_extent(ifp, &icur, &got))
 475				break;
 476			continue;
 477		}
 478
 479		error = xfs_bmap_del_extent_delay(ip, XFS_DATA_FORK, &icur,
 480						  &got, &del);
 481		if (error || !xfs_iext_get_extent(ifp, &icur, &got))
 482			break;
 483	}
 484
 
 
 
 485out_unlock:
 486	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 487	return error;
 488}
 489
 490/*
 491 * Test whether it is appropriate to check an inode for and free post EOF
 492 * blocks. The 'force' parameter determines whether we should also consider
 493 * regular files that are marked preallocated or append-only.
 494 */
 495bool
 496xfs_can_free_eofblocks(
 497	struct xfs_inode	*ip,
 498	bool			force)
 499{
 500	struct xfs_bmbt_irec	imap;
 501	struct xfs_mount	*mp = ip->i_mount;
 
 502	xfs_fileoff_t		end_fsb;
 503	xfs_fileoff_t		last_fsb;
 504	int			nimaps = 1;
 505	int			error;
 506
 507	/*
 508	 * Caller must either hold the exclusive io lock; or be inactivating
 509	 * the inode, which guarantees there are no other users of the inode.
 510	 */
 511	if (!(VFS_I(ip)->i_state & I_FREEING))
 512		xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL);
 513
 514	/* prealloc/delalloc exists only on regular files */
 515	if (!S_ISREG(VFS_I(ip)->i_mode))
 516		return false;
 517
 518	/*
 519	 * Zero sized files with no cached pages and delalloc blocks will not
 520	 * have speculative prealloc/delalloc blocks to remove.
 521	 */
 522	if (VFS_I(ip)->i_size == 0 &&
 523	    VFS_I(ip)->i_mapping->nrpages == 0 &&
 524	    ip->i_delayed_blks == 0)
 525		return false;
 526
 527	/* If we haven't read in the extent list, then don't do it now. */
 528	if (xfs_need_iread_extents(&ip->i_df))
 529		return false;
 530
 531	/*
 532	 * Do not free real preallocated or append-only files unless the file
 533	 * has delalloc blocks and we are forced to remove them.
 534	 */
 535	if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
 536		if (!force || ip->i_delayed_blks == 0)
 537			return false;
 538
 539	/*
 540	 * Do not try to free post-EOF blocks if EOF is beyond the end of the
 541	 * range supported by the page cache, because the truncation will loop
 542	 * forever.
 543	 */
 544	end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
 545	if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1)
 546		end_fsb = xfs_rtb_roundup_rtx(mp, end_fsb);
 547	last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
 548	if (last_fsb <= end_fsb)
 549		return false;
 550
 551	/*
 552	 * Look up the mapping for the first block past EOF.  If we can't find
 553	 * it, there's nothing to free.
 
 
 554	 */
 555	xfs_ilock(ip, XFS_ILOCK_SHARED);
 556	error = xfs_bmapi_read(ip, end_fsb, last_fsb - end_fsb, &imap, &nimaps,
 557			0);
 
 558	xfs_iunlock(ip, XFS_ILOCK_SHARED);
 559	if (error || nimaps == 0)
 560		return false;
 561
 562	/*
 563	 * If there's a real mapping there or there are delayed allocation
 564	 * reservations, then we have post-EOF blocks to try to free.
 565	 */
 566	return imap.br_startblock != HOLESTARTBLOCK || ip->i_delayed_blks;
 567}
 568
 569/*
 570 * This is called to free any blocks beyond eof. The caller must hold
 571 * IOLOCK_EXCL unless we are in the inode reclaim path and have the only
 572 * reference to the inode.
 573 */
 574int
 575xfs_free_eofblocks(
 576	struct xfs_inode	*ip)
 577{
 578	struct xfs_trans	*tp;
 579	struct xfs_mount	*mp = ip->i_mount;
 580	int			error;
 581
 582	/* Attach the dquots to the inode up front. */
 583	error = xfs_qm_dqattach(ip);
 584	if (error)
 585		return error;
 586
 587	/* Wait on dio to ensure i_size has settled. */
 588	inode_dio_wait(VFS_I(ip));
 589
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 590	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
 591	if (error) {
 592		ASSERT(xfs_is_shutdown(mp));
 593		return error;
 594	}
 595
 596	xfs_ilock(ip, XFS_ILOCK_EXCL);
 597	xfs_trans_ijoin(tp, ip, 0);
 598
 599	/*
 600	 * Do not update the on-disk file size.  If we update the on-disk file
 601	 * size and then the system crashes before the contents of the file are
 602	 * flushed to disk then the files may be full of holes (ie NULL files
 603	 * bug).
 604	 */
 605	error = xfs_itruncate_extents_flags(&tp, ip, XFS_DATA_FORK,
 606				XFS_ISIZE(ip), XFS_BMAPI_NODISCARD);
 607	if (error)
 608		goto err_cancel;
 609
 610	error = xfs_trans_commit(tp);
 611	if (error)
 612		goto out_unlock;
 613
 614	xfs_inode_clear_eofblocks_tag(ip);
 615	goto out_unlock;
 616
 617err_cancel:
 618	/*
 619	 * If we get an error at this point we simply don't
 620	 * bother truncating the file.
 621	 */
 622	xfs_trans_cancel(tp);
 623out_unlock:
 624	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 625	return error;
 626}
 627
 628int
 629xfs_alloc_file_space(
 630	struct xfs_inode	*ip,
 631	xfs_off_t		offset,
 632	xfs_off_t		len)
 633{
 634	xfs_mount_t		*mp = ip->i_mount;
 635	xfs_off_t		count;
 636	xfs_filblks_t		allocatesize_fsb;
 637	xfs_extlen_t		extsz, temp;
 638	xfs_fileoff_t		startoffset_fsb;
 639	xfs_fileoff_t		endoffset_fsb;
 640	int			rt;
 641	xfs_trans_t		*tp;
 642	xfs_bmbt_irec_t		imaps[1], *imapp;
 643	int			error;
 644
 
 
 
 645	trace_xfs_alloc_file_space(ip);
 646
 647	if (xfs_is_shutdown(mp))
 648		return -EIO;
 649
 650	error = xfs_qm_dqattach(ip);
 651	if (error)
 652		return error;
 653
 654	if (len <= 0)
 655		return -EINVAL;
 656
 657	rt = XFS_IS_REALTIME_INODE(ip);
 658	extsz = xfs_get_extsz_hint(ip);
 659
 660	count = len;
 661	imapp = &imaps[0];
 662	startoffset_fsb	= XFS_B_TO_FSBT(mp, offset);
 663	endoffset_fsb = XFS_B_TO_FSB(mp, offset + count);
 664	allocatesize_fsb = endoffset_fsb - startoffset_fsb;
 665
 666	/*
 667	 * Allocate file space until done or until there is an error
 668	 */
 669	while (allocatesize_fsb && !error) {
 670		xfs_fileoff_t	s, e;
 671		unsigned int	dblocks, rblocks, resblks;
 672		int		nimaps = 1;
 673
 674		/*
 675		 * Determine space reservations for data/realtime.
 676		 */
 677		if (unlikely(extsz)) {
 678			s = startoffset_fsb;
 679			do_div(s, extsz);
 680			s *= extsz;
 681			e = startoffset_fsb + allocatesize_fsb;
 682			div_u64_rem(startoffset_fsb, extsz, &temp);
 683			if (temp)
 684				e += temp;
 685			div_u64_rem(e, extsz, &temp);
 686			if (temp)
 687				e += extsz - temp;
 688		} else {
 689			s = 0;
 690			e = allocatesize_fsb;
 691		}
 692
 693		/*
 694		 * The transaction reservation is limited to a 32-bit block
 695		 * count, hence we need to limit the number of blocks we are
 696		 * trying to reserve to avoid an overflow. We can't allocate
 697		 * more than @nimaps extents, and an extent is limited on disk
 698		 * to XFS_BMBT_MAX_EXTLEN (21 bits), so use that to enforce the
 699		 * limit.
 700		 */
 701		resblks = min_t(xfs_fileoff_t, (e - s),
 702				(XFS_MAX_BMBT_EXTLEN * nimaps));
 703		if (unlikely(rt)) {
 704			dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
 705			rblocks = resblks;
 706		} else {
 707			dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
 708			rblocks = 0;
 709		}
 710
 711		error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write,
 712				dblocks, rblocks, false, &tp);
 713		if (error)
 714			break;
 715
 716		error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
 717				XFS_IEXT_ADD_NOSPLIT_CNT);
 718		if (error == -EFBIG)
 719			error = xfs_iext_count_upgrade(tp, ip,
 720					XFS_IEXT_ADD_NOSPLIT_CNT);
 721		if (error)
 722			goto error;
 723
 724		error = xfs_bmapi_write(tp, ip, startoffset_fsb,
 725				allocatesize_fsb, XFS_BMAPI_PREALLOC, 0, imapp,
 726				&nimaps);
 727		if (error)
 728			goto error;
 729
 730		ip->i_diflags |= XFS_DIFLAG_PREALLOC;
 731		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 732
 733		error = xfs_trans_commit(tp);
 734		xfs_iunlock(ip, XFS_ILOCK_EXCL);
 735		if (error)
 736			break;
 737
 738		/*
 739		 * If the allocator cannot find a single free extent large
 740		 * enough to cover the start block of the requested range,
 741		 * xfs_bmapi_write will return 0 but leave *nimaps set to 0.
 742		 *
 743		 * In that case we simply need to keep looping with the same
 744		 * startoffset_fsb so that one of the following allocations
 745		 * will eventually reach the requested range.
 746		 */
 747		if (nimaps) {
 
 
 
 
 
 
 
 748			startoffset_fsb += imapp->br_blockcount;
 749			allocatesize_fsb -= imapp->br_blockcount;
 750		}
 
 
 
 
 
 
 751	}
 752
 753	return error;
 754
 755error:
 756	xfs_trans_cancel(tp);
 757	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 758	return error;
 759}
 760
 761static int
 762xfs_unmap_extent(
 763	struct xfs_inode	*ip,
 764	xfs_fileoff_t		startoffset_fsb,
 765	xfs_filblks_t		len_fsb,
 766	int			*done)
 767{
 768	struct xfs_mount	*mp = ip->i_mount;
 769	struct xfs_trans	*tp;
 770	uint			resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
 771	int			error;
 772
 773	error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, resblks, 0,
 774			false, &tp);
 775	if (error)
 776		return error;
 777
 778	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
 779			XFS_IEXT_PUNCH_HOLE_CNT);
 780	if (error == -EFBIG)
 781		error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
 782	if (error)
 783		goto out_trans_cancel;
 784
 785	error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done);
 786	if (error)
 787		goto out_trans_cancel;
 788
 789	error = xfs_trans_commit(tp);
 790out_unlock:
 791	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 792	return error;
 793
 794out_trans_cancel:
 795	xfs_trans_cancel(tp);
 796	goto out_unlock;
 797}
 798
 799/* Caller must first wait for the completion of any pending DIOs if required. */
 800int
 801xfs_flush_unmap_range(
 802	struct xfs_inode	*ip,
 803	xfs_off_t		offset,
 804	xfs_off_t		len)
 805{
 806	struct xfs_mount	*mp = ip->i_mount;
 807	struct inode		*inode = VFS_I(ip);
 808	xfs_off_t		rounding, start, end;
 809	int			error;
 810
 811	rounding = max_t(xfs_off_t, mp->m_sb.sb_blocksize, PAGE_SIZE);
 812	start = round_down(offset, rounding);
 813	end = round_up(offset + len, rounding) - 1;
 
 
 
 
 
 814
 815	error = filemap_write_and_wait_range(inode->i_mapping, start, end);
 816	if (error)
 817		return error;
 818	truncate_pagecache_range(inode, start, end);
 819	return 0;
 820}
 821
 822int
 823xfs_free_file_space(
 824	struct xfs_inode	*ip,
 825	xfs_off_t		offset,
 826	xfs_off_t		len)
 827{
 828	struct xfs_mount	*mp = ip->i_mount;
 829	xfs_fileoff_t		startoffset_fsb;
 830	xfs_fileoff_t		endoffset_fsb;
 831	int			done = 0, error;
 832
 833	trace_xfs_free_file_space(ip);
 834
 835	error = xfs_qm_dqattach(ip);
 836	if (error)
 837		return error;
 838
 839	if (len <= 0)	/* if nothing being freed */
 840		return 0;
 841
 
 
 
 
 
 
 
 
 842	startoffset_fsb = XFS_B_TO_FSB(mp, offset);
 843	endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
 844
 845	/* We can only free complete realtime extents. */
 846	if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1) {
 847		startoffset_fsb = xfs_rtb_roundup_rtx(mp, startoffset_fsb);
 848		endoffset_fsb = xfs_rtb_rounddown_rtx(mp, endoffset_fsb);
 849	}
 850
 851	/*
 852	 * Need to zero the stuff we're not freeing, on disk.
 853	 */
 854	if (endoffset_fsb > startoffset_fsb) {
 855		while (!done) {
 856			error = xfs_unmap_extent(ip, startoffset_fsb,
 857					endoffset_fsb - startoffset_fsb, &done);
 858			if (error)
 859				return error;
 860		}
 861	}
 862
 863	/*
 864	 * Now that we've unmap all full blocks we'll have to zero out any
 865	 * partial block at the beginning and/or end.  xfs_zero_range is smart
 866	 * enough to skip any holes, including those we just created, but we
 867	 * must take care not to zero beyond EOF and enlarge i_size.
 868	 */
 869	if (offset >= XFS_ISIZE(ip))
 870		return 0;
 871	if (offset + len > XFS_ISIZE(ip))
 872		len = XFS_ISIZE(ip) - offset;
 873	error = xfs_zero_range(ip, offset, len, NULL);
 874	if (error)
 875		return error;
 876
 877	/*
 878	 * If we zeroed right up to EOF and EOF straddles a page boundary we
 879	 * must make sure that the post-EOF area is also zeroed because the
 880	 * page could be mmap'd and xfs_zero_range doesn't do that for us.
 881	 * Writeback of the eof page will do this, albeit clumsily.
 882	 */
 883	if (offset + len >= XFS_ISIZE(ip) && offset_in_page(offset + len) > 0) {
 884		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
 885				round_down(offset + len, PAGE_SIZE), LLONG_MAX);
 886	}
 887
 888	return error;
 889}
 890
 891static int
 892xfs_prepare_shift(
 893	struct xfs_inode	*ip,
 894	loff_t			offset)
 895{
 896	struct xfs_mount	*mp = ip->i_mount;
 897	int			error;
 898
 899	/*
 900	 * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
 901	 * into the accessible region of the file.
 902	 */
 903	if (xfs_can_free_eofblocks(ip, true)) {
 904		error = xfs_free_eofblocks(ip);
 905		if (error)
 906			return error;
 907	}
 908
 909	/*
 910	 * Shift operations must stabilize the start block offset boundary along
 911	 * with the full range of the operation. If we don't, a COW writeback
 912	 * completion could race with an insert, front merge with the start
 913	 * extent (after split) during the shift and corrupt the file. Start
 914	 * with the block just prior to the start to stabilize the boundary.
 
 915	 */
 916	offset = round_down(offset, mp->m_sb.sb_blocksize);
 
 917	if (offset)
 918		offset -= mp->m_sb.sb_blocksize;
 919
 920	/*
 921	 * Writeback and invalidate cache for the remainder of the file as we're
 922	 * about to shift down every extent from offset to EOF.
 923	 */
 924	error = xfs_flush_unmap_range(ip, offset, XFS_ISIZE(ip));
 925	if (error)
 926		return error;
 927
 928	/*
 929	 * Clean out anything hanging around in the cow fork now that
 930	 * we've flushed all the dirty data out to disk to avoid having
 931	 * CoW extents at the wrong offsets.
 932	 */
 933	if (xfs_inode_has_cow_data(ip)) {
 934		error = xfs_reflink_cancel_cow_range(ip, offset, NULLFILEOFF,
 935				true);
 936		if (error)
 937			return error;
 938	}
 939
 940	return 0;
 941}
 942
 943/*
 944 * xfs_collapse_file_space()
 945 *	This routine frees disk space and shift extent for the given file.
 946 *	The first thing we do is to free data blocks in the specified range
 947 *	by calling xfs_free_file_space(). It would also sync dirty data
 948 *	and invalidate page cache over the region on which collapse range
 949 *	is working. And Shift extent records to the left to cover a hole.
 950 * RETURNS:
 951 *	0 on success
 952 *	errno on error
 953 *
 954 */
 955int
 956xfs_collapse_file_space(
 957	struct xfs_inode	*ip,
 958	xfs_off_t		offset,
 959	xfs_off_t		len)
 960{
 961	struct xfs_mount	*mp = ip->i_mount;
 962	struct xfs_trans	*tp;
 963	int			error;
 964	xfs_fileoff_t		next_fsb = XFS_B_TO_FSB(mp, offset + len);
 965	xfs_fileoff_t		shift_fsb = XFS_B_TO_FSB(mp, len);
 966	bool			done = false;
 967
 968	xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
 969
 970	trace_xfs_collapse_file_space(ip);
 971
 972	error = xfs_free_file_space(ip, offset, len);
 973	if (error)
 974		return error;
 975
 976	error = xfs_prepare_shift(ip, offset);
 977	if (error)
 978		return error;
 979
 980	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
 981	if (error)
 982		return error;
 983
 984	xfs_ilock(ip, XFS_ILOCK_EXCL);
 985	xfs_trans_ijoin(tp, ip, 0);
 986
 987	while (!done) {
 988		error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb,
 989				&done);
 990		if (error)
 991			goto out_trans_cancel;
 992		if (done)
 993			break;
 994
 995		/* finish any deferred frees and roll the transaction */
 996		error = xfs_defer_finish(&tp);
 997		if (error)
 998			goto out_trans_cancel;
 999	}
1000
1001	error = xfs_trans_commit(tp);
1002	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1003	return error;
1004
1005out_trans_cancel:
1006	xfs_trans_cancel(tp);
1007	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1008	return error;
1009}
1010
1011/*
1012 * xfs_insert_file_space()
1013 *	This routine create hole space by shifting extents for the given file.
1014 *	The first thing we do is to sync dirty data and invalidate page cache
1015 *	over the region on which insert range is working. And split an extent
1016 *	to two extents at given offset by calling xfs_bmap_split_extent.
1017 *	And shift all extent records which are laying between [offset,
1018 *	last allocated extent] to the right to reserve hole range.
1019 * RETURNS:
1020 *	0 on success
1021 *	errno on error
1022 */
1023int
1024xfs_insert_file_space(
1025	struct xfs_inode	*ip,
1026	loff_t			offset,
1027	loff_t			len)
1028{
1029	struct xfs_mount	*mp = ip->i_mount;
1030	struct xfs_trans	*tp;
1031	int			error;
1032	xfs_fileoff_t		stop_fsb = XFS_B_TO_FSB(mp, offset);
1033	xfs_fileoff_t		next_fsb = NULLFSBLOCK;
1034	xfs_fileoff_t		shift_fsb = XFS_B_TO_FSB(mp, len);
1035	bool			done = false;
1036
1037	xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
1038
1039	trace_xfs_insert_file_space(ip);
1040
1041	error = xfs_bmap_can_insert_extents(ip, stop_fsb, shift_fsb);
1042	if (error)
1043		return error;
1044
1045	error = xfs_prepare_shift(ip, offset);
1046	if (error)
1047		return error;
1048
1049	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write,
1050			XFS_DIOSTRAT_SPACE_RES(mp, 0), 0, 0, &tp);
1051	if (error)
1052		return error;
1053
1054	xfs_ilock(ip, XFS_ILOCK_EXCL);
1055	xfs_trans_ijoin(tp, ip, 0);
1056
1057	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
1058			XFS_IEXT_PUNCH_HOLE_CNT);
1059	if (error == -EFBIG)
1060		error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
1061	if (error)
1062		goto out_trans_cancel;
1063
1064	/*
1065	 * The extent shifting code works on extent granularity. So, if stop_fsb
1066	 * is not the starting block of extent, we need to split the extent at
1067	 * stop_fsb.
1068	 */
1069	error = xfs_bmap_split_extent(tp, ip, stop_fsb);
1070	if (error)
1071		goto out_trans_cancel;
1072
1073	do {
1074		error = xfs_defer_finish(&tp);
1075		if (error)
1076			goto out_trans_cancel;
1077
1078		error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb,
1079				&done, stop_fsb);
1080		if (error)
1081			goto out_trans_cancel;
1082	} while (!done);
1083
1084	error = xfs_trans_commit(tp);
1085	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1086	return error;
1087
1088out_trans_cancel:
1089	xfs_trans_cancel(tp);
1090	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1091	return error;
1092}
1093
1094/*
1095 * We need to check that the format of the data fork in the temporary inode is
1096 * valid for the target inode before doing the swap. This is not a problem with
1097 * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
1098 * data fork depending on the space the attribute fork is taking so we can get
1099 * invalid formats on the target inode.
1100 *
1101 * E.g. target has space for 7 extents in extent format, temp inode only has
1102 * space for 6.  If we defragment down to 7 extents, then the tmp format is a
1103 * btree, but when swapped it needs to be in extent format. Hence we can't just
1104 * blindly swap data forks on attr2 filesystems.
1105 *
1106 * Note that we check the swap in both directions so that we don't end up with
1107 * a corrupt temporary inode, either.
1108 *
1109 * Note that fixing the way xfs_fsr sets up the attribute fork in the source
1110 * inode will prevent this situation from occurring, so all we do here is
1111 * reject and log the attempt. basically we are putting the responsibility on
1112 * userspace to get this right.
1113 */
1114static int
1115xfs_swap_extents_check_format(
1116	struct xfs_inode	*ip,	/* target inode */
1117	struct xfs_inode	*tip)	/* tmp inode */
1118{
1119	struct xfs_ifork	*ifp = &ip->i_df;
1120	struct xfs_ifork	*tifp = &tip->i_df;
1121
1122	/* User/group/project quota ids must match if quotas are enforced. */
1123	if (XFS_IS_QUOTA_ON(ip->i_mount) &&
1124	    (!uid_eq(VFS_I(ip)->i_uid, VFS_I(tip)->i_uid) ||
1125	     !gid_eq(VFS_I(ip)->i_gid, VFS_I(tip)->i_gid) ||
1126	     ip->i_projid != tip->i_projid))
1127		return -EINVAL;
1128
1129	/* Should never get a local format */
1130	if (ifp->if_format == XFS_DINODE_FMT_LOCAL ||
1131	    tifp->if_format == XFS_DINODE_FMT_LOCAL)
1132		return -EINVAL;
1133
1134	/*
1135	 * if the target inode has less extents that then temporary inode then
1136	 * why did userspace call us?
1137	 */
1138	if (ifp->if_nextents < tifp->if_nextents)
1139		return -EINVAL;
1140
1141	/*
1142	 * If we have to use the (expensive) rmap swap method, we can
1143	 * handle any number of extents and any format.
1144	 */
1145	if (xfs_has_rmapbt(ip->i_mount))
1146		return 0;
1147
1148	/*
1149	 * if the target inode is in extent form and the temp inode is in btree
1150	 * form then we will end up with the target inode in the wrong format
1151	 * as we already know there are less extents in the temp inode.
1152	 */
1153	if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1154	    tifp->if_format == XFS_DINODE_FMT_BTREE)
1155		return -EINVAL;
1156
1157	/* Check temp in extent form to max in target */
1158	if (tifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1159	    tifp->if_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1160		return -EINVAL;
1161
1162	/* Check target in extent form to max in temp */
1163	if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1164	    ifp->if_nextents > XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1165		return -EINVAL;
1166
1167	/*
1168	 * If we are in a btree format, check that the temp root block will fit
1169	 * in the target and that it has enough extents to be in btree format
1170	 * in the target.
1171	 *
1172	 * Note that we have to be careful to allow btree->extent conversions
1173	 * (a common defrag case) which will occur when the temp inode is in
1174	 * extent format...
1175	 */
1176	if (tifp->if_format == XFS_DINODE_FMT_BTREE) {
1177		if (xfs_inode_has_attr_fork(ip) &&
1178		    XFS_BMAP_BMDR_SPACE(tifp->if_broot) > xfs_inode_fork_boff(ip))
1179			return -EINVAL;
1180		if (tifp->if_nextents <= XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1181			return -EINVAL;
1182	}
1183
1184	/* Reciprocal target->temp btree format checks */
1185	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
1186		if (xfs_inode_has_attr_fork(tip) &&
1187		    XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > xfs_inode_fork_boff(tip))
1188			return -EINVAL;
1189		if (ifp->if_nextents <= XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1190			return -EINVAL;
1191	}
1192
1193	return 0;
1194}
1195
1196static int
1197xfs_swap_extent_flush(
1198	struct xfs_inode	*ip)
1199{
1200	int	error;
1201
1202	error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
1203	if (error)
1204		return error;
1205	truncate_pagecache_range(VFS_I(ip), 0, -1);
1206
1207	/* Verify O_DIRECT for ftmp */
1208	if (VFS_I(ip)->i_mapping->nrpages)
1209		return -EINVAL;
1210	return 0;
1211}
1212
1213/*
1214 * Move extents from one file to another, when rmap is enabled.
1215 */
1216STATIC int
1217xfs_swap_extent_rmap(
1218	struct xfs_trans		**tpp,
1219	struct xfs_inode		*ip,
1220	struct xfs_inode		*tip)
1221{
1222	struct xfs_trans		*tp = *tpp;
1223	struct xfs_bmbt_irec		irec;
1224	struct xfs_bmbt_irec		uirec;
1225	struct xfs_bmbt_irec		tirec;
1226	xfs_fileoff_t			offset_fsb;
1227	xfs_fileoff_t			end_fsb;
1228	xfs_filblks_t			count_fsb;
1229	int				error;
1230	xfs_filblks_t			ilen;
1231	xfs_filblks_t			rlen;
1232	int				nimaps;
1233	uint64_t			tip_flags2;
1234
1235	/*
1236	 * If the source file has shared blocks, we must flag the donor
1237	 * file as having shared blocks so that we get the shared-block
1238	 * rmap functions when we go to fix up the rmaps.  The flags
1239	 * will be switch for reals later.
1240	 */
1241	tip_flags2 = tip->i_diflags2;
1242	if (ip->i_diflags2 & XFS_DIFLAG2_REFLINK)
1243		tip->i_diflags2 |= XFS_DIFLAG2_REFLINK;
1244
1245	offset_fsb = 0;
1246	end_fsb = XFS_B_TO_FSB(ip->i_mount, i_size_read(VFS_I(ip)));
1247	count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb);
1248
1249	while (count_fsb) {
1250		/* Read extent from the donor file */
1251		nimaps = 1;
1252		error = xfs_bmapi_read(tip, offset_fsb, count_fsb, &tirec,
1253				&nimaps, 0);
1254		if (error)
1255			goto out;
1256		ASSERT(nimaps == 1);
1257		ASSERT(tirec.br_startblock != DELAYSTARTBLOCK);
1258
1259		trace_xfs_swap_extent_rmap_remap(tip, &tirec);
1260		ilen = tirec.br_blockcount;
1261
1262		/* Unmap the old blocks in the source file. */
1263		while (tirec.br_blockcount) {
1264			ASSERT(tp->t_highest_agno == NULLAGNUMBER);
1265			trace_xfs_swap_extent_rmap_remap_piece(tip, &tirec);
1266
1267			/* Read extent from the source file */
1268			nimaps = 1;
1269			error = xfs_bmapi_read(ip, tirec.br_startoff,
1270					tirec.br_blockcount, &irec,
1271					&nimaps, 0);
1272			if (error)
1273				goto out;
1274			ASSERT(nimaps == 1);
1275			ASSERT(tirec.br_startoff == irec.br_startoff);
1276			trace_xfs_swap_extent_rmap_remap_piece(ip, &irec);
1277
1278			/* Trim the extent. */
1279			uirec = tirec;
1280			uirec.br_blockcount = rlen = min_t(xfs_filblks_t,
1281					tirec.br_blockcount,
1282					irec.br_blockcount);
1283			trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec);
1284
1285			if (xfs_bmap_is_real_extent(&uirec)) {
1286				error = xfs_iext_count_may_overflow(ip,
1287						XFS_DATA_FORK,
1288						XFS_IEXT_SWAP_RMAP_CNT);
1289				if (error == -EFBIG)
1290					error = xfs_iext_count_upgrade(tp, ip,
1291							XFS_IEXT_SWAP_RMAP_CNT);
1292				if (error)
1293					goto out;
1294			}
1295
1296			if (xfs_bmap_is_real_extent(&irec)) {
1297				error = xfs_iext_count_may_overflow(tip,
1298						XFS_DATA_FORK,
1299						XFS_IEXT_SWAP_RMAP_CNT);
1300				if (error == -EFBIG)
1301					error = xfs_iext_count_upgrade(tp, ip,
1302							XFS_IEXT_SWAP_RMAP_CNT);
1303				if (error)
1304					goto out;
1305			}
1306
1307			/* Remove the mapping from the donor file. */
1308			xfs_bmap_unmap_extent(tp, tip, XFS_DATA_FORK, &uirec);
1309
1310			/* Remove the mapping from the source file. */
1311			xfs_bmap_unmap_extent(tp, ip, XFS_DATA_FORK, &irec);
1312
1313			/* Map the donor file's blocks into the source file. */
1314			xfs_bmap_map_extent(tp, ip, XFS_DATA_FORK, &uirec);
1315
1316			/* Map the source file's blocks into the donor file. */
1317			xfs_bmap_map_extent(tp, tip, XFS_DATA_FORK, &irec);
1318
1319			error = xfs_defer_finish(tpp);
1320			tp = *tpp;
1321			if (error)
1322				goto out;
1323
1324			tirec.br_startoff += rlen;
1325			if (tirec.br_startblock != HOLESTARTBLOCK &&
1326			    tirec.br_startblock != DELAYSTARTBLOCK)
1327				tirec.br_startblock += rlen;
1328			tirec.br_blockcount -= rlen;
1329		}
1330
1331		/* Roll on... */
1332		count_fsb -= ilen;
1333		offset_fsb += ilen;
1334	}
1335
1336	tip->i_diflags2 = tip_flags2;
1337	return 0;
1338
1339out:
1340	trace_xfs_swap_extent_rmap_error(ip, error, _RET_IP_);
1341	tip->i_diflags2 = tip_flags2;
1342	return error;
1343}
1344
1345/* Swap the extents of two files by swapping data forks. */
1346STATIC int
1347xfs_swap_extent_forks(
1348	struct xfs_trans	*tp,
1349	struct xfs_inode	*ip,
1350	struct xfs_inode	*tip,
1351	int			*src_log_flags,
1352	int			*target_log_flags)
1353{
1354	xfs_filblks_t		aforkblks = 0;
1355	xfs_filblks_t		taforkblks = 0;
1356	xfs_extnum_t		junk;
1357	uint64_t		tmp;
1358	int			error;
1359
1360	/*
1361	 * Count the number of extended attribute blocks
1362	 */
1363	if (xfs_inode_has_attr_fork(ip) && ip->i_af.if_nextents > 0 &&
1364	    ip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
1365		error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &junk,
1366				&aforkblks);
1367		if (error)
1368			return error;
1369	}
1370	if (xfs_inode_has_attr_fork(tip) && tip->i_af.if_nextents > 0 &&
1371	    tip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
1372		error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK, &junk,
1373				&taforkblks);
1374		if (error)
1375			return error;
1376	}
1377
1378	/*
1379	 * Btree format (v3) inodes have the inode number stamped in the bmbt
1380	 * block headers. We can't start changing the bmbt blocks until the
1381	 * inode owner change is logged so recovery does the right thing in the
1382	 * event of a crash. Set the owner change log flags now and leave the
1383	 * bmbt scan as the last step.
1384	 */
1385	if (xfs_has_v3inodes(ip->i_mount)) {
1386		if (ip->i_df.if_format == XFS_DINODE_FMT_BTREE)
1387			(*target_log_flags) |= XFS_ILOG_DOWNER;
1388		if (tip->i_df.if_format == XFS_DINODE_FMT_BTREE)
1389			(*src_log_flags) |= XFS_ILOG_DOWNER;
1390	}
1391
1392	/*
1393	 * Swap the data forks of the inodes
1394	 */
1395	swap(ip->i_df, tip->i_df);
1396
1397	/*
1398	 * Fix the on-disk inode values
1399	 */
1400	tmp = (uint64_t)ip->i_nblocks;
1401	ip->i_nblocks = tip->i_nblocks - taforkblks + aforkblks;
1402	tip->i_nblocks = tmp + taforkblks - aforkblks;
1403
1404	/*
1405	 * The extents in the source inode could still contain speculative
1406	 * preallocation beyond EOF (e.g. the file is open but not modified
1407	 * while defrag is in progress). In that case, we need to copy over the
1408	 * number of delalloc blocks the data fork in the source inode is
1409	 * tracking beyond EOF so that when the fork is truncated away when the
1410	 * temporary inode is unlinked we don't underrun the i_delayed_blks
1411	 * counter on that inode.
1412	 */
1413	ASSERT(tip->i_delayed_blks == 0);
1414	tip->i_delayed_blks = ip->i_delayed_blks;
1415	ip->i_delayed_blks = 0;
1416
1417	switch (ip->i_df.if_format) {
1418	case XFS_DINODE_FMT_EXTENTS:
1419		(*src_log_flags) |= XFS_ILOG_DEXT;
1420		break;
1421	case XFS_DINODE_FMT_BTREE:
1422		ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
1423		       (*src_log_flags & XFS_ILOG_DOWNER));
1424		(*src_log_flags) |= XFS_ILOG_DBROOT;
1425		break;
1426	}
1427
1428	switch (tip->i_df.if_format) {
1429	case XFS_DINODE_FMT_EXTENTS:
1430		(*target_log_flags) |= XFS_ILOG_DEXT;
1431		break;
1432	case XFS_DINODE_FMT_BTREE:
1433		(*target_log_flags) |= XFS_ILOG_DBROOT;
1434		ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
1435		       (*target_log_flags & XFS_ILOG_DOWNER));
1436		break;
1437	}
1438
1439	return 0;
1440}
1441
1442/*
1443 * Fix up the owners of the bmbt blocks to refer to the current inode. The
1444 * change owner scan attempts to order all modified buffers in the current
1445 * transaction. In the event of ordered buffer failure, the offending buffer is
1446 * physically logged as a fallback and the scan returns -EAGAIN. We must roll
1447 * the transaction in this case to replenish the fallback log reservation and
1448 * restart the scan. This process repeats until the scan completes.
1449 */
1450static int
1451xfs_swap_change_owner(
1452	struct xfs_trans	**tpp,
1453	struct xfs_inode	*ip,
1454	struct xfs_inode	*tmpip)
1455{
1456	int			error;
1457	struct xfs_trans	*tp = *tpp;
1458
1459	do {
1460		error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK, ip->i_ino,
1461					      NULL);
1462		/* success or fatal error */
1463		if (error != -EAGAIN)
1464			break;
1465
1466		error = xfs_trans_roll(tpp);
1467		if (error)
1468			break;
1469		tp = *tpp;
1470
1471		/*
1472		 * Redirty both inodes so they can relog and keep the log tail
1473		 * moving forward.
1474		 */
1475		xfs_trans_ijoin(tp, ip, 0);
1476		xfs_trans_ijoin(tp, tmpip, 0);
1477		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1478		xfs_trans_log_inode(tp, tmpip, XFS_ILOG_CORE);
1479	} while (true);
1480
1481	return error;
1482}
1483
1484int
1485xfs_swap_extents(
1486	struct xfs_inode	*ip,	/* target inode */
1487	struct xfs_inode	*tip,	/* tmp inode */
1488	struct xfs_swapext	*sxp)
1489{
1490	struct xfs_mount	*mp = ip->i_mount;
1491	struct xfs_trans	*tp;
1492	struct xfs_bstat	*sbp = &sxp->sx_stat;
1493	int			src_log_flags, target_log_flags;
1494	int			error = 0;
1495	uint64_t		f;
1496	int			resblks = 0;
1497	unsigned int		flags = 0;
1498	struct timespec64	ctime, mtime;
1499
1500	/*
1501	 * Lock the inodes against other IO, page faults and truncate to
1502	 * begin with.  Then we can ensure the inodes are flushed and have no
1503	 * page cache safely. Once we have done this we can take the ilocks and
1504	 * do the rest of the checks.
1505	 */
1506	lock_two_nondirectories(VFS_I(ip), VFS_I(tip));
1507	filemap_invalidate_lock_two(VFS_I(ip)->i_mapping,
1508				    VFS_I(tip)->i_mapping);
1509
1510	/* Verify that both files have the same format */
1511	if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
1512		error = -EINVAL;
1513		goto out_unlock;
1514	}
1515
1516	/* Verify both files are either real-time or non-realtime */
1517	if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
1518		error = -EINVAL;
 
 
 
 
 
 
 
 
 
 
 
 
1519		goto out_unlock;
1520	}
1521
1522	error = xfs_qm_dqattach(ip);
1523	if (error)
1524		goto out_unlock;
1525
1526	error = xfs_qm_dqattach(tip);
1527	if (error)
1528		goto out_unlock;
1529
1530	error = xfs_swap_extent_flush(ip);
1531	if (error)
1532		goto out_unlock;
1533	error = xfs_swap_extent_flush(tip);
1534	if (error)
1535		goto out_unlock;
1536
1537	if (xfs_inode_has_cow_data(tip)) {
1538		error = xfs_reflink_cancel_cow_range(tip, 0, NULLFILEOFF, true);
1539		if (error)
1540			goto out_unlock;
1541	}
1542
1543	/*
1544	 * Extent "swapping" with rmap requires a permanent reservation and
1545	 * a block reservation because it's really just a remap operation
1546	 * performed with log redo items!
1547	 */
1548	if (xfs_has_rmapbt(mp)) {
1549		int		w = XFS_DATA_FORK;
1550		uint32_t	ipnext = ip->i_df.if_nextents;
1551		uint32_t	tipnext	= tip->i_df.if_nextents;
1552
1553		/*
1554		 * Conceptually this shouldn't affect the shape of either bmbt,
1555		 * but since we atomically move extents one by one, we reserve
1556		 * enough space to rebuild both trees.
1557		 */
1558		resblks = XFS_SWAP_RMAP_SPACE_RES(mp, ipnext, w);
1559		resblks +=  XFS_SWAP_RMAP_SPACE_RES(mp, tipnext, w);
1560
1561		/*
1562		 * If either inode straddles a bmapbt block allocation boundary,
1563		 * the rmapbt algorithm triggers repeated allocs and frees as
1564		 * extents are remapped. This can exhaust the block reservation
1565		 * prematurely and cause shutdown. Return freed blocks to the
1566		 * transaction reservation to counter this behavior.
1567		 */
1568		flags |= XFS_TRANS_RES_FDBLKS;
1569	}
1570	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, flags,
1571				&tp);
1572	if (error)
1573		goto out_unlock;
1574
1575	/*
1576	 * Lock and join the inodes to the tansaction so that transaction commit
1577	 * or cancel will unlock the inodes from this point onwards.
1578	 */
1579	xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL);
1580	xfs_trans_ijoin(tp, ip, 0);
1581	xfs_trans_ijoin(tp, tip, 0);
1582
1583
1584	/* Verify all data are being swapped */
1585	if (sxp->sx_offset != 0 ||
1586	    sxp->sx_length != ip->i_disk_size ||
1587	    sxp->sx_length != tip->i_disk_size) {
1588		error = -EFAULT;
1589		goto out_trans_cancel;
1590	}
1591
1592	trace_xfs_swap_extent_before(ip, 0);
1593	trace_xfs_swap_extent_before(tip, 1);
1594
1595	/* check inode formats now that data is flushed */
1596	error = xfs_swap_extents_check_format(ip, tip);
1597	if (error) {
1598		xfs_notice(mp,
1599		    "%s: inode 0x%llx format is incompatible for exchanging.",
1600				__func__, ip->i_ino);
1601		goto out_trans_cancel;
1602	}
1603
1604	/*
1605	 * Compare the current change & modify times with that
1606	 * passed in.  If they differ, we abort this swap.
1607	 * This is the mechanism used to ensure the calling
1608	 * process that the file was not changed out from
1609	 * under it.
1610	 */
1611	ctime = inode_get_ctime(VFS_I(ip));
1612	mtime = inode_get_mtime(VFS_I(ip));
1613	if ((sbp->bs_ctime.tv_sec != ctime.tv_sec) ||
1614	    (sbp->bs_ctime.tv_nsec != ctime.tv_nsec) ||
1615	    (sbp->bs_mtime.tv_sec != mtime.tv_sec) ||
1616	    (sbp->bs_mtime.tv_nsec != mtime.tv_nsec)) {
1617		error = -EBUSY;
1618		goto out_trans_cancel;
1619	}
1620
1621	/*
1622	 * Note the trickiness in setting the log flags - we set the owner log
1623	 * flag on the opposite inode (i.e. the inode we are setting the new
1624	 * owner to be) because once we swap the forks and log that, log
1625	 * recovery is going to see the fork as owned by the swapped inode,
1626	 * not the pre-swapped inodes.
1627	 */
1628	src_log_flags = XFS_ILOG_CORE;
1629	target_log_flags = XFS_ILOG_CORE;
1630
1631	if (xfs_has_rmapbt(mp))
1632		error = xfs_swap_extent_rmap(&tp, ip, tip);
1633	else
1634		error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags,
1635				&target_log_flags);
1636	if (error)
1637		goto out_trans_cancel;
1638
1639	/* Do we have to swap reflink flags? */
1640	if ((ip->i_diflags2 & XFS_DIFLAG2_REFLINK) ^
1641	    (tip->i_diflags2 & XFS_DIFLAG2_REFLINK)) {
1642		f = ip->i_diflags2 & XFS_DIFLAG2_REFLINK;
1643		ip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
1644		ip->i_diflags2 |= tip->i_diflags2 & XFS_DIFLAG2_REFLINK;
1645		tip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
1646		tip->i_diflags2 |= f & XFS_DIFLAG2_REFLINK;
1647	}
1648
1649	/* Swap the cow forks. */
1650	if (xfs_has_reflink(mp)) {
1651		ASSERT(!ip->i_cowfp ||
1652		       ip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
1653		ASSERT(!tip->i_cowfp ||
1654		       tip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
1655
1656		swap(ip->i_cowfp, tip->i_cowfp);
1657
1658		if (ip->i_cowfp && ip->i_cowfp->if_bytes)
1659			xfs_inode_set_cowblocks_tag(ip);
1660		else
1661			xfs_inode_clear_cowblocks_tag(ip);
1662		if (tip->i_cowfp && tip->i_cowfp->if_bytes)
1663			xfs_inode_set_cowblocks_tag(tip);
1664		else
1665			xfs_inode_clear_cowblocks_tag(tip);
1666	}
1667
1668	xfs_trans_log_inode(tp, ip,  src_log_flags);
1669	xfs_trans_log_inode(tp, tip, target_log_flags);
1670
1671	/*
1672	 * The extent forks have been swapped, but crc=1,rmapbt=0 filesystems
1673	 * have inode number owner values in the bmbt blocks that still refer to
1674	 * the old inode. Scan each bmbt to fix up the owner values with the
1675	 * inode number of the current inode.
1676	 */
1677	if (src_log_flags & XFS_ILOG_DOWNER) {
1678		error = xfs_swap_change_owner(&tp, ip, tip);
1679		if (error)
1680			goto out_trans_cancel;
1681	}
1682	if (target_log_flags & XFS_ILOG_DOWNER) {
1683		error = xfs_swap_change_owner(&tp, tip, ip);
1684		if (error)
1685			goto out_trans_cancel;
1686	}
1687
1688	/*
1689	 * If this is a synchronous mount, make sure that the
1690	 * transaction goes to disk before returning to the user.
1691	 */
1692	if (xfs_has_wsync(mp))
1693		xfs_trans_set_sync(tp);
1694
1695	error = xfs_trans_commit(tp);
1696
1697	trace_xfs_swap_extent_after(ip, 0);
1698	trace_xfs_swap_extent_after(tip, 1);
1699
1700out_unlock_ilock:
1701	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1702	xfs_iunlock(tip, XFS_ILOCK_EXCL);
1703out_unlock:
1704	filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping,
1705				      VFS_I(tip)->i_mapping);
1706	unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
1707	return error;
1708
1709out_trans_cancel:
1710	xfs_trans_cancel(tp);
1711	goto out_unlock_ilock;
1712}