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_sb.h"
  13#include "xfs_mount.h"
  14#include "xfs_inode.h"
 
  15#include "xfs_trans.h"
  16#include "xfs_trans_priv.h"
  17#include "xfs_inode_item.h"
  18#include "xfs_quota.h"
  19#include "xfs_trace.h"
  20#include "xfs_icache.h"
  21#include "xfs_bmap_util.h"
  22#include "xfs_dquot_item.h"
  23#include "xfs_dquot.h"
  24#include "xfs_reflink.h"
  25#include "xfs_ialloc.h"
  26
  27#include <linux/iversion.h>
 
 
 
 
  28
  29/*
  30 * Allocate and initialise an xfs_inode.
  31 */
  32struct xfs_inode *
  33xfs_inode_alloc(
  34	struct xfs_mount	*mp,
  35	xfs_ino_t		ino)
  36{
  37	struct xfs_inode	*ip;
  38
  39	/*
  40	 * XXX: If this didn't occur in transactions, we could drop GFP_NOFAIL
  41	 * and return NULL here on ENOMEM.
 
  42	 */
  43	ip = kmem_cache_alloc(xfs_inode_zone, GFP_KERNEL | __GFP_NOFAIL);
  44
 
  45	if (inode_init_always(mp->m_super, VFS_I(ip))) {
  46		kmem_cache_free(xfs_inode_zone, ip);
  47		return NULL;
  48	}
  49
  50	/* VFS doesn't initialise i_mode! */
  51	VFS_I(ip)->i_mode = 0;
  52
  53	XFS_STATS_INC(mp, vn_active);
  54	ASSERT(atomic_read(&ip->i_pincount) == 0);
 
  55	ASSERT(!xfs_isiflocked(ip));
  56	ASSERT(ip->i_ino == 0);
  57
 
 
  58	/* initialise the xfs inode */
  59	ip->i_ino = ino;
  60	ip->i_mount = mp;
  61	memset(&ip->i_imap, 0, sizeof(struct xfs_imap));
  62	ip->i_afp = NULL;
  63	ip->i_cowfp = NULL;
  64	memset(&ip->i_df, 0, sizeof(ip->i_df));
  65	ip->i_flags = 0;
  66	ip->i_delayed_blks = 0;
  67	memset(&ip->i_d, 0, sizeof(ip->i_d));
  68	ip->i_sick = 0;
  69	ip->i_checked = 0;
  70	INIT_WORK(&ip->i_ioend_work, xfs_end_io);
  71	INIT_LIST_HEAD(&ip->i_ioend_list);
  72	spin_lock_init(&ip->i_ioend_lock);
  73
  74	return ip;
  75}
  76
  77STATIC void
  78xfs_inode_free_callback(
  79	struct rcu_head		*head)
  80{
  81	struct inode		*inode = container_of(head, struct inode, i_rcu);
  82	struct xfs_inode	*ip = XFS_I(inode);
  83
 
 
 
 
 
 
 
  84	switch (VFS_I(ip)->i_mode & S_IFMT) {
  85	case S_IFREG:
  86	case S_IFDIR:
  87	case S_IFLNK:
  88		xfs_idestroy_fork(&ip->i_df);
  89		break;
  90	}
  91
  92	if (ip->i_afp) {
  93		xfs_idestroy_fork(ip->i_afp);
  94		kmem_cache_free(xfs_ifork_zone, ip->i_afp);
  95	}
  96	if (ip->i_cowfp) {
  97		xfs_idestroy_fork(ip->i_cowfp);
  98		kmem_cache_free(xfs_ifork_zone, ip->i_cowfp);
  99	}
 100	if (ip->i_itemp) {
 101		ASSERT(!test_bit(XFS_LI_IN_AIL,
 102				 &ip->i_itemp->ili_item.li_flags));
 103		xfs_inode_item_destroy(ip);
 104		ip->i_itemp = NULL;
 105	}
 106
 107	kmem_cache_free(xfs_inode_zone, ip);
 108}
 109
 110static void
 111__xfs_inode_free(
 112	struct xfs_inode	*ip)
 113{
 114	/* asserts to verify all state is correct here */
 115	ASSERT(atomic_read(&ip->i_pincount) == 0);
 116	ASSERT(!ip->i_itemp || list_empty(&ip->i_itemp->ili_item.li_bio_list));
 117	XFS_STATS_DEC(ip->i_mount, vn_active);
 118
 119	call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
 120}
 121
 122void
 123xfs_inode_free(
 124	struct xfs_inode	*ip)
 125{
 126	ASSERT(!xfs_isiflocked(ip));
 127
 128	/*
 129	 * Because we use RCU freeing we need to ensure the inode always
 130	 * appears to be reclaimed with an invalid inode number when in the
 131	 * free state. The ip->i_flags_lock provides the barrier against lookup
 132	 * races.
 133	 */
 134	spin_lock(&ip->i_flags_lock);
 135	ip->i_flags = XFS_IRECLAIM;
 136	ip->i_ino = 0;
 137	spin_unlock(&ip->i_flags_lock);
 138
 139	__xfs_inode_free(ip);
 140}
 141
 142/*
 143 * Queue background inode reclaim work if there are reclaimable inodes and there
 144 * isn't reclaim work already scheduled or in progress.
 145 */
 146static void
 147xfs_reclaim_work_queue(
 148	struct xfs_mount        *mp)
 149{
 150
 151	rcu_read_lock();
 152	if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
 153		queue_delayed_work(mp->m_reclaim_workqueue, &mp->m_reclaim_work,
 154			msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10));
 155	}
 156	rcu_read_unlock();
 157}
 158
 159static void
 160xfs_perag_set_reclaim_tag(
 161	struct xfs_perag	*pag)
 162{
 163	struct xfs_mount	*mp = pag->pag_mount;
 164
 165	lockdep_assert_held(&pag->pag_ici_lock);
 166	if (pag->pag_ici_reclaimable++)
 167		return;
 168
 169	/* propagate the reclaim tag up into the perag radix tree */
 170	spin_lock(&mp->m_perag_lock);
 171	radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno,
 172			   XFS_ICI_RECLAIM_TAG);
 173	spin_unlock(&mp->m_perag_lock);
 174
 175	/* schedule periodic background inode reclaim */
 176	xfs_reclaim_work_queue(mp);
 177
 178	trace_xfs_perag_set_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
 179}
 180
 181static void
 182xfs_perag_clear_reclaim_tag(
 183	struct xfs_perag	*pag)
 184{
 185	struct xfs_mount	*mp = pag->pag_mount;
 186
 187	lockdep_assert_held(&pag->pag_ici_lock);
 188	if (--pag->pag_ici_reclaimable)
 189		return;
 190
 191	/* clear the reclaim tag from the perag radix tree */
 192	spin_lock(&mp->m_perag_lock);
 193	radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno,
 194			     XFS_ICI_RECLAIM_TAG);
 195	spin_unlock(&mp->m_perag_lock);
 196	trace_xfs_perag_clear_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
 197}
 198
 199
 200/*
 201 * We set the inode flag atomically with the radix tree tag.
 202 * Once we get tag lookups on the radix tree, this inode flag
 203 * can go away.
 204 */
 205void
 206xfs_inode_set_reclaim_tag(
 207	struct xfs_inode	*ip)
 208{
 209	struct xfs_mount	*mp = ip->i_mount;
 210	struct xfs_perag	*pag;
 211
 212	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
 213	spin_lock(&pag->pag_ici_lock);
 214	spin_lock(&ip->i_flags_lock);
 215
 216	radix_tree_tag_set(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino),
 217			   XFS_ICI_RECLAIM_TAG);
 218	xfs_perag_set_reclaim_tag(pag);
 219	__xfs_iflags_set(ip, XFS_IRECLAIMABLE);
 220
 221	spin_unlock(&ip->i_flags_lock);
 222	spin_unlock(&pag->pag_ici_lock);
 223	xfs_perag_put(pag);
 224}
 225
 226STATIC void
 227xfs_inode_clear_reclaim_tag(
 228	struct xfs_perag	*pag,
 229	xfs_ino_t		ino)
 230{
 231	radix_tree_tag_clear(&pag->pag_ici_root,
 232			     XFS_INO_TO_AGINO(pag->pag_mount, ino),
 233			     XFS_ICI_RECLAIM_TAG);
 234	xfs_perag_clear_reclaim_tag(pag);
 235}
 236
 237static void
 238xfs_inew_wait(
 239	struct xfs_inode	*ip)
 240{
 241	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_INEW_BIT);
 242	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_INEW_BIT);
 243
 244	do {
 245		prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
 246		if (!xfs_iflags_test(ip, XFS_INEW))
 247			break;
 248		schedule();
 249	} while (true);
 250	finish_wait(wq, &wait.wq_entry);
 251}
 252
 253/*
 254 * When we recycle a reclaimable inode, we need to re-initialise the VFS inode
 255 * part of the structure. This is made more complex by the fact we store
 256 * information about the on-disk values in the VFS inode and so we can't just
 257 * overwrite the values unconditionally. Hence we save the parameters we
 258 * need to retain across reinitialisation, and rewrite them into the VFS inode
 259 * after reinitialisation even if it fails.
 260 */
 261static int
 262xfs_reinit_inode(
 263	struct xfs_mount	*mp,
 264	struct inode		*inode)
 265{
 266	int		error;
 267	uint32_t	nlink = inode->i_nlink;
 268	uint32_t	generation = inode->i_generation;
 269	uint64_t	version = inode_peek_iversion(inode);
 270	umode_t		mode = inode->i_mode;
 271	dev_t		dev = inode->i_rdev;
 272	kuid_t		uid = inode->i_uid;
 273	kgid_t		gid = inode->i_gid;
 274
 275	error = inode_init_always(mp->m_super, inode);
 276
 277	set_nlink(inode, nlink);
 278	inode->i_generation = generation;
 279	inode_set_iversion_queried(inode, version);
 280	inode->i_mode = mode;
 281	inode->i_rdev = dev;
 282	inode->i_uid = uid;
 283	inode->i_gid = gid;
 284	return error;
 285}
 286
 287/*
 288 * If we are allocating a new inode, then check what was returned is
 289 * actually a free, empty inode. If we are not allocating an inode,
 290 * then check we didn't find a free inode.
 291 *
 292 * Returns:
 293 *	0		if the inode free state matches the lookup context
 294 *	-ENOENT		if the inode is free and we are not allocating
 295 *	-EFSCORRUPTED	if there is any state mismatch at all
 296 */
 297static int
 298xfs_iget_check_free_state(
 299	struct xfs_inode	*ip,
 300	int			flags)
 301{
 302	if (flags & XFS_IGET_CREATE) {
 303		/* should be a free inode */
 304		if (VFS_I(ip)->i_mode != 0) {
 305			xfs_warn(ip->i_mount,
 306"Corruption detected! Free inode 0x%llx not marked free! (mode 0x%x)",
 307				ip->i_ino, VFS_I(ip)->i_mode);
 308			return -EFSCORRUPTED;
 309		}
 310
 311		if (ip->i_d.di_nblocks != 0) {
 312			xfs_warn(ip->i_mount,
 313"Corruption detected! Free inode 0x%llx has blocks allocated!",
 314				ip->i_ino);
 315			return -EFSCORRUPTED;
 316		}
 317		return 0;
 318	}
 319
 320	/* should be an allocated inode */
 321	if (VFS_I(ip)->i_mode == 0)
 322		return -ENOENT;
 323
 324	return 0;
 325}
 326
 327/*
 328 * Check the validity of the inode we just found it the cache
 329 */
 330static int
 331xfs_iget_cache_hit(
 332	struct xfs_perag	*pag,
 333	struct xfs_inode	*ip,
 334	xfs_ino_t		ino,
 335	int			flags,
 336	int			lock_flags) __releases(RCU)
 337{
 338	struct inode		*inode = VFS_I(ip);
 339	struct xfs_mount	*mp = ip->i_mount;
 340	int			error;
 341
 342	/*
 343	 * check for re-use of an inode within an RCU grace period due to the
 344	 * radix tree nodes not being updated yet. We monitor for this by
 345	 * setting the inode number to zero before freeing the inode structure.
 346	 * If the inode has been reallocated and set up, then the inode number
 347	 * will not match, so check for that, too.
 348	 */
 349	spin_lock(&ip->i_flags_lock);
 350	if (ip->i_ino != ino) {
 351		trace_xfs_iget_skip(ip);
 352		XFS_STATS_INC(mp, xs_ig_frecycle);
 353		error = -EAGAIN;
 354		goto out_error;
 355	}
 356
 357
 358	/*
 359	 * If we are racing with another cache hit that is currently
 360	 * instantiating this inode or currently recycling it out of
 361	 * reclaimabe state, wait for the initialisation to complete
 362	 * before continuing.
 363	 *
 364	 * XXX(hch): eventually we should do something equivalent to
 365	 *	     wait_on_inode to wait for these flags to be cleared
 366	 *	     instead of polling for it.
 367	 */
 368	if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) {
 369		trace_xfs_iget_skip(ip);
 370		XFS_STATS_INC(mp, xs_ig_frecycle);
 371		error = -EAGAIN;
 372		goto out_error;
 373	}
 374
 375	/*
 376	 * Check the inode free state is valid. This also detects lookup
 377	 * racing with unlinks.
 378	 */
 379	error = xfs_iget_check_free_state(ip, flags);
 380	if (error)
 381		goto out_error;
 
 382
 383	/*
 384	 * If IRECLAIMABLE is set, we've torn down the VFS inode already.
 385	 * Need to carefully get it back into useable state.
 386	 */
 387	if (ip->i_flags & XFS_IRECLAIMABLE) {
 388		trace_xfs_iget_reclaim(ip);
 389
 390		if (flags & XFS_IGET_INCORE) {
 391			error = -EAGAIN;
 392			goto out_error;
 393		}
 394
 395		/*
 396		 * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode
 397		 * from stomping over us while we recycle the inode.  We can't
 398		 * clear the radix tree reclaimable tag yet as it requires
 399		 * pag_ici_lock to be held exclusive.
 400		 */
 401		ip->i_flags |= XFS_IRECLAIM;
 402
 403		spin_unlock(&ip->i_flags_lock);
 404		rcu_read_unlock();
 405
 406		ASSERT(!rwsem_is_locked(&inode->i_rwsem));
 407		error = xfs_reinit_inode(mp, inode);
 408		if (error) {
 409			bool wake;
 410			/*
 411			 * Re-initializing the inode failed, and we are in deep
 412			 * trouble.  Try to re-add it to the reclaim list.
 413			 */
 414			rcu_read_lock();
 415			spin_lock(&ip->i_flags_lock);
 416			wake = !!__xfs_iflags_test(ip, XFS_INEW);
 417			ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM);
 418			if (wake)
 419				wake_up_bit(&ip->i_flags, __XFS_INEW_BIT);
 420			ASSERT(ip->i_flags & XFS_IRECLAIMABLE);
 421			trace_xfs_iget_reclaim_fail(ip);
 422			goto out_error;
 423		}
 424
 425		spin_lock(&pag->pag_ici_lock);
 426		spin_lock(&ip->i_flags_lock);
 427
 428		/*
 429		 * Clear the per-lifetime state in the inode as we are now
 430		 * effectively a new inode and need to return to the initial
 431		 * state before reuse occurs.
 432		 */
 433		ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
 434		ip->i_flags |= XFS_INEW;
 435		xfs_inode_clear_reclaim_tag(pag, ip->i_ino);
 436		inode->i_state = I_NEW;
 437		ip->i_sick = 0;
 438		ip->i_checked = 0;
 
 439
 440		spin_unlock(&ip->i_flags_lock);
 441		spin_unlock(&pag->pag_ici_lock);
 442	} else {
 443		/* If the VFS inode is being torn down, pause and try again. */
 444		if (!igrab(inode)) {
 445			trace_xfs_iget_skip(ip);
 446			error = -EAGAIN;
 447			goto out_error;
 448		}
 449
 450		/* We've got a live one. */
 451		spin_unlock(&ip->i_flags_lock);
 452		rcu_read_unlock();
 453		trace_xfs_iget_hit(ip);
 454	}
 455
 456	if (lock_flags != 0)
 457		xfs_ilock(ip, lock_flags);
 458
 459	if (!(flags & XFS_IGET_INCORE))
 460		xfs_iflags_clear(ip, XFS_ISTALE);
 461	XFS_STATS_INC(mp, xs_ig_found);
 462
 463	return 0;
 464
 465out_error:
 466	spin_unlock(&ip->i_flags_lock);
 467	rcu_read_unlock();
 468	return error;
 469}
 470
 471
 472static int
 473xfs_iget_cache_miss(
 474	struct xfs_mount	*mp,
 475	struct xfs_perag	*pag,
 476	xfs_trans_t		*tp,
 477	xfs_ino_t		ino,
 478	struct xfs_inode	**ipp,
 479	int			flags,
 480	int			lock_flags)
 481{
 482	struct xfs_inode	*ip;
 483	int			error;
 484	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, ino);
 485	int			iflags;
 486
 487	ip = xfs_inode_alloc(mp, ino);
 488	if (!ip)
 489		return -ENOMEM;
 490
 491	error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, flags);
 492	if (error)
 493		goto out_destroy;
 494
 495	/*
 496	 * For version 5 superblocks, if we are initialising a new inode and we
 497	 * are not utilising the XFS_MOUNT_IKEEP inode cluster mode, we can
 498	 * simply build the new inode core with a random generation number.
 499	 *
 500	 * For version 4 (and older) superblocks, log recovery is dependent on
 501	 * the di_flushiter field being initialised from the current on-disk
 502	 * value and hence we must also read the inode off disk even when
 503	 * initializing new inodes.
 504	 */
 505	if (xfs_sb_version_has_v3inode(&mp->m_sb) &&
 506	    (flags & XFS_IGET_CREATE) && !(mp->m_flags & XFS_MOUNT_IKEEP)) {
 507		VFS_I(ip)->i_generation = prandom_u32();
 508	} else {
 509		struct xfs_dinode	*dip;
 510		struct xfs_buf		*bp;
 511
 512		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0);
 513		if (error)
 514			goto out_destroy;
 515
 516		error = xfs_inode_from_disk(ip, dip);
 517		if (!error)
 518			xfs_buf_set_ref(bp, XFS_INO_REF);
 519		xfs_trans_brelse(tp, bp);
 520
 521		if (error)
 522			goto out_destroy;
 523	}
 524
 525	trace_xfs_iget_miss(ip);
 526
 527	/*
 528	 * Check the inode free state is valid. This also detects lookup
 529	 * racing with unlinks.
 530	 */
 531	error = xfs_iget_check_free_state(ip, flags);
 532	if (error)
 533		goto out_destroy;
 
 534
 535	/*
 536	 * Preload the radix tree so we can insert safely under the
 537	 * write spinlock. Note that we cannot sleep inside the preload
 538	 * region. Since we can be called from transaction context, don't
 539	 * recurse into the file system.
 540	 */
 541	if (radix_tree_preload(GFP_NOFS)) {
 542		error = -EAGAIN;
 543		goto out_destroy;
 544	}
 545
 546	/*
 547	 * Because the inode hasn't been added to the radix-tree yet it can't
 548	 * be found by another thread, so we can do the non-sleeping lock here.
 549	 */
 550	if (lock_flags) {
 551		if (!xfs_ilock_nowait(ip, lock_flags))
 552			BUG();
 553	}
 554
 555	/*
 556	 * These values must be set before inserting the inode into the radix
 557	 * tree as the moment it is inserted a concurrent lookup (allowed by the
 558	 * RCU locking mechanism) can find it and that lookup must see that this
 559	 * is an inode currently under construction (i.e. that XFS_INEW is set).
 560	 * The ip->i_flags_lock that protects the XFS_INEW flag forms the
 561	 * memory barrier that ensures this detection works correctly at lookup
 562	 * time.
 563	 */
 564	iflags = XFS_INEW;
 565	if (flags & XFS_IGET_DONTCACHE)
 566		d_mark_dontcache(VFS_I(ip));
 567	ip->i_udquot = NULL;
 568	ip->i_gdquot = NULL;
 569	ip->i_pdquot = NULL;
 570	xfs_iflags_set(ip, iflags);
 571
 572	/* insert the new inode */
 573	spin_lock(&pag->pag_ici_lock);
 574	error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
 575	if (unlikely(error)) {
 576		WARN_ON(error != -EEXIST);
 577		XFS_STATS_INC(mp, xs_ig_dup);
 578		error = -EAGAIN;
 579		goto out_preload_end;
 580	}
 581	spin_unlock(&pag->pag_ici_lock);
 582	radix_tree_preload_end();
 583
 584	*ipp = ip;
 585	return 0;
 586
 587out_preload_end:
 588	spin_unlock(&pag->pag_ici_lock);
 589	radix_tree_preload_end();
 590	if (lock_flags)
 591		xfs_iunlock(ip, lock_flags);
 592out_destroy:
 593	__destroy_inode(VFS_I(ip));
 594	xfs_inode_free(ip);
 595	return error;
 596}
 597
 598/*
 599 * Look up an inode by number in the given file system.  The inode is looked up
 600 * in the cache held in each AG.  If the inode is found in the cache, initialise
 601 * the vfs inode if necessary.
 
 602 *
 603 * If it is not in core, read it in from the file system's device, add it to the
 604 * cache and initialise the vfs inode.
 605 *
 606 * The inode is locked according to the value of the lock_flags parameter.
 607 * Inode lookup is only done during metadata operations and not as part of the
 608 * data IO path. Hence we only allow locking of the XFS_ILOCK during lookup.
 
 
 
 
 
 
 
 
 
 609 */
 610int
 611xfs_iget(
 612	struct xfs_mount	*mp,
 613	struct xfs_trans	*tp,
 614	xfs_ino_t		ino,
 615	uint			flags,
 616	uint			lock_flags,
 617	struct xfs_inode	**ipp)
 618{
 619	struct xfs_inode	*ip;
 620	struct xfs_perag	*pag;
 621	xfs_agino_t		agino;
 622	int			error;
 623
 
 
 
 
 
 
 
 624	ASSERT((lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) == 0);
 625
 626	/* reject inode numbers outside existing AGs */
 627	if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
 628		return -EINVAL;
 629
 630	XFS_STATS_INC(mp, xs_ig_attempts);
 631
 632	/* get the perag structure and ensure that it's inode capable */
 633	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
 634	agino = XFS_INO_TO_AGINO(mp, ino);
 635
 636again:
 637	error = 0;
 638	rcu_read_lock();
 639	ip = radix_tree_lookup(&pag->pag_ici_root, agino);
 640
 641	if (ip) {
 642		error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags);
 643		if (error)
 644			goto out_error_or_again;
 645	} else {
 646		rcu_read_unlock();
 647		if (flags & XFS_IGET_INCORE) {
 648			error = -ENODATA;
 649			goto out_error_or_again;
 650		}
 651		XFS_STATS_INC(mp, xs_ig_missed);
 652
 653		error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip,
 654							flags, lock_flags);
 655		if (error)
 656			goto out_error_or_again;
 657	}
 658	xfs_perag_put(pag);
 659
 660	*ipp = ip;
 661
 662	/*
 663	 * If we have a real type for an on-disk inode, we can setup the inode
 664	 * now.	 If it's a new inode being created, xfs_ialloc will handle it.
 665	 */
 666	if (xfs_iflags_test(ip, XFS_INEW) && VFS_I(ip)->i_mode != 0)
 667		xfs_setup_existing_inode(ip);
 668	return 0;
 669
 670out_error_or_again:
 671	if (!(flags & XFS_IGET_INCORE) && error == -EAGAIN) {
 672		delay(1);
 673		goto again;
 674	}
 675	xfs_perag_put(pag);
 676	return error;
 677}
 678
 679/*
 680 * "Is this a cached inode that's also allocated?"
 681 *
 682 * Look up an inode by number in the given file system.  If the inode is
 683 * in cache and isn't in purgatory, return 1 if the inode is allocated
 684 * and 0 if it is not.  For all other cases (not in cache, being torn
 685 * down, etc.), return a negative error code.
 686 *
 687 * The caller has to prevent inode allocation and freeing activity,
 688 * presumably by locking the AGI buffer.   This is to ensure that an
 689 * inode cannot transition from allocated to freed until the caller is
 690 * ready to allow that.  If the inode is in an intermediate state (new,
 691 * reclaimable, or being reclaimed), -EAGAIN will be returned; if the
 692 * inode is not in the cache, -ENOENT will be returned.  The caller must
 693 * deal with these scenarios appropriately.
 694 *
 695 * This is a specialized use case for the online scrubber; if you're
 696 * reading this, you probably want xfs_iget.
 697 */
 698int
 699xfs_icache_inode_is_allocated(
 700	struct xfs_mount	*mp,
 701	struct xfs_trans	*tp,
 702	xfs_ino_t		ino,
 703	bool			*inuse)
 704{
 705	struct xfs_inode	*ip;
 706	int			error;
 707
 708	error = xfs_iget(mp, tp, ino, XFS_IGET_INCORE, 0, &ip);
 709	if (error)
 710		return error;
 711
 712	*inuse = !!(VFS_I(ip)->i_mode);
 713	xfs_irele(ip);
 714	return 0;
 715}
 716
 717/*
 718 * The inode lookup is done in batches to keep the amount of lock traffic and
 719 * radix tree lookups to a minimum. The batch size is a trade off between
 720 * lookup reduction and stack usage. This is in the reclaim path, so we can't
 721 * be too greedy.
 722 */
 723#define XFS_LOOKUP_BATCH	32
 724
 725/*
 726 * Decide if the given @ip is eligible to be a part of the inode walk, and
 727 * grab it if so.  Returns true if it's ready to go or false if we should just
 728 * ignore it.
 729 */
 730STATIC bool
 731xfs_inode_walk_ag_grab(
 732	struct xfs_inode	*ip,
 733	int			flags)
 734{
 735	struct inode		*inode = VFS_I(ip);
 736	bool			newinos = !!(flags & XFS_INODE_WALK_INEW_WAIT);
 737
 738	ASSERT(rcu_read_lock_held());
 739
 740	/* Check for stale RCU freed inode */
 
 
 
 
 
 
 
 
 741	spin_lock(&ip->i_flags_lock);
 742	if (!ip->i_ino)
 743		goto out_unlock_noent;
 744
 745	/* avoid new or reclaimable inodes. Leave for reclaim code to flush */
 746	if ((!newinos && __xfs_iflags_test(ip, XFS_INEW)) ||
 747	    __xfs_iflags_test(ip, XFS_IRECLAIMABLE | XFS_IRECLAIM))
 748		goto out_unlock_noent;
 749	spin_unlock(&ip->i_flags_lock);
 750
 751	/* nothing to sync during shutdown */
 752	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
 753		return false;
 754
 755	/* If we can't grab the inode, it must on it's way to reclaim. */
 756	if (!igrab(inode))
 757		return false;
 758
 759	/* inode is valid */
 760	return true;
 761
 762out_unlock_noent:
 763	spin_unlock(&ip->i_flags_lock);
 764	return false;
 765}
 766
 767/*
 768 * For a given per-AG structure @pag, grab, @execute, and rele all incore
 769 * inodes with the given radix tree @tag.
 770 */
 771STATIC int
 772xfs_inode_walk_ag(
 
 773	struct xfs_perag	*pag,
 774	int			iter_flags,
 775	int			(*execute)(struct xfs_inode *ip, void *args),
 
 776	void			*args,
 777	int			tag)
 778{
 779	struct xfs_mount	*mp = pag->pag_mount;
 780	uint32_t		first_index;
 781	int			last_error = 0;
 782	int			skipped;
 783	bool			done;
 784	int			nr_found;
 785
 786restart:
 787	done = false;
 788	skipped = 0;
 789	first_index = 0;
 790	nr_found = 0;
 791	do {
 792		struct xfs_inode *batch[XFS_LOOKUP_BATCH];
 793		int		error = 0;
 794		int		i;
 795
 796		rcu_read_lock();
 797
 798		if (tag == XFS_ICI_NO_TAG)
 799			nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
 800					(void **)batch, first_index,
 801					XFS_LOOKUP_BATCH);
 802		else
 803			nr_found = radix_tree_gang_lookup_tag(
 804					&pag->pag_ici_root,
 805					(void **) batch, first_index,
 806					XFS_LOOKUP_BATCH, tag);
 807
 808		if (!nr_found) {
 809			rcu_read_unlock();
 810			break;
 811		}
 812
 813		/*
 814		 * Grab the inodes before we drop the lock. if we found
 815		 * nothing, nr == 0 and the loop will be skipped.
 816		 */
 817		for (i = 0; i < nr_found; i++) {
 818			struct xfs_inode *ip = batch[i];
 819
 820			if (done || !xfs_inode_walk_ag_grab(ip, iter_flags))
 821				batch[i] = NULL;
 822
 823			/*
 824			 * Update the index for the next lookup. Catch
 825			 * overflows into the next AG range which can occur if
 826			 * we have inodes in the last block of the AG and we
 827			 * are currently pointing to the last inode.
 828			 *
 829			 * Because we may see inodes that are from the wrong AG
 830			 * due to RCU freeing and reallocation, only update the
 831			 * index if it lies in this AG. It was a race that lead
 832			 * us to see this inode, so another lookup from the
 833			 * same index will not find it again.
 834			 */
 835			if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
 836				continue;
 837			first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
 838			if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
 839				done = true;
 840		}
 841
 842		/* unlock now we've grabbed the inodes. */
 843		rcu_read_unlock();
 844
 845		for (i = 0; i < nr_found; i++) {
 846			if (!batch[i])
 847				continue;
 848			if ((iter_flags & XFS_INODE_WALK_INEW_WAIT) &&
 849			    xfs_iflags_test(batch[i], XFS_INEW))
 850				xfs_inew_wait(batch[i]);
 851			error = execute(batch[i], args);
 852			xfs_irele(batch[i]);
 853			if (error == -EAGAIN) {
 854				skipped++;
 855				continue;
 856			}
 857			if (error && last_error != -EFSCORRUPTED)
 858				last_error = error;
 859		}
 860
 861		/* bail out if the filesystem is corrupted.  */
 862		if (error == -EFSCORRUPTED)
 863			break;
 864
 865		cond_resched();
 866
 867	} while (nr_found && !done);
 868
 869	if (skipped) {
 870		delay(1);
 871		goto restart;
 872	}
 873	return last_error;
 874}
 875
 876/* Fetch the next (possibly tagged) per-AG structure. */
 877static inline struct xfs_perag *
 878xfs_inode_walk_get_perag(
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 879	struct xfs_mount	*mp,
 880	xfs_agnumber_t		agno,
 881	int			tag)
 
 
 882{
 883	if (tag == XFS_ICI_NO_TAG)
 884		return xfs_perag_get(mp, agno);
 885	return xfs_perag_get_tag(mp, agno, tag);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 886}
 887
 888/*
 889 * Call the @execute function on all incore inodes matching the radix tree
 890 * @tag.
 891 */
 892int
 893xfs_inode_walk(
 894	struct xfs_mount	*mp,
 895	int			iter_flags,
 896	int			(*execute)(struct xfs_inode *ip, void *args),
 
 897	void			*args,
 898	int			tag)
 899{
 900	struct xfs_perag	*pag;
 901	int			error = 0;
 902	int			last_error = 0;
 903	xfs_agnumber_t		ag;
 904
 905	ag = 0;
 906	while ((pag = xfs_inode_walk_get_perag(mp, ag, tag))) {
 907		ag = pag->pag_agno + 1;
 908		error = xfs_inode_walk_ag(pag, iter_flags, execute, args, tag);
 909		xfs_perag_put(pag);
 910		if (error) {
 911			last_error = error;
 912			if (error == -EFSCORRUPTED)
 913				break;
 914		}
 915	}
 916	return last_error;
 917}
 918
 919/*
 920 * Background scanning to trim post-EOF preallocated space. This is queued
 921 * based on the 'speculative_prealloc_lifetime' tunable (5m by default).
 
 
 
 922 */
 923void
 924xfs_queue_eofblocks(
 925	struct xfs_mount *mp)
 926{
 
 927	rcu_read_lock();
 928	if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_EOFBLOCKS_TAG))
 929		queue_delayed_work(mp->m_eofblocks_workqueue,
 930				   &mp->m_eofblocks_work,
 931				   msecs_to_jiffies(xfs_eofb_secs * 1000));
 932	rcu_read_unlock();
 933}
 934
 
 
 
 
 
 
 
 935void
 936xfs_eofblocks_worker(
 937	struct work_struct *work)
 938{
 939	struct xfs_mount *mp = container_of(to_delayed_work(work),
 940				struct xfs_mount, m_eofblocks_work);
 941
 942	if (!sb_start_write_trylock(mp->m_super))
 943		return;
 944	xfs_icache_free_eofblocks(mp, NULL);
 945	sb_end_write(mp->m_super);
 946
 947	xfs_queue_eofblocks(mp);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 948}
 949
 950/*
 951 * Background scanning to trim preallocated CoW space. This is queued
 952 * based on the 'speculative_cow_prealloc_lifetime' tunable (5m by default).
 953 * (We'll just piggyback on the post-EOF prealloc space workqueue.)
 954 */
 955void
 956xfs_queue_cowblocks(
 957	struct xfs_mount *mp)
 958{
 959	rcu_read_lock();
 960	if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_COWBLOCKS_TAG))
 961		queue_delayed_work(mp->m_eofblocks_workqueue,
 962				   &mp->m_cowblocks_work,
 963				   msecs_to_jiffies(xfs_cowb_secs * 1000));
 964	rcu_read_unlock();
 
 
 
 
 
 965}
 966
 967void
 968xfs_cowblocks_worker(
 969	struct work_struct *work)
 
 970{
 971	struct xfs_mount *mp = container_of(to_delayed_work(work),
 972				struct xfs_mount, m_cowblocks_work);
 973
 974	if (!sb_start_write_trylock(mp->m_super))
 975		return;
 976	xfs_icache_free_cowblocks(mp, NULL);
 977	sb_end_write(mp->m_super);
 
 
 
 
 
 978
 979	xfs_queue_cowblocks(mp);
 
 
 
 
 
 
 
 
 980}
 981
 982/*
 983 * Grab the inode for reclaim exclusively.
 984 *
 985 * We have found this inode via a lookup under RCU, so the inode may have
 986 * already been freed, or it may be in the process of being recycled by
 987 * xfs_iget(). In both cases, the inode will have XFS_IRECLAIM set. If the inode
 988 * has been fully recycled by the time we get the i_flags_lock, XFS_IRECLAIMABLE
 989 * will not be set. Hence we need to check for both these flag conditions to
 990 * avoid inodes that are no longer reclaim candidates.
 991 *
 992 * Note: checking for other state flags here, under the i_flags_lock or not, is
 993 * racy and should be avoided. Those races should be resolved only after we have
 994 * ensured that we are able to reclaim this inode and the world can see that we
 995 * are going to reclaim it.
 996 *
 997 * Return true if we grabbed it, false otherwise.
 998 */
 999static bool
1000xfs_reclaim_inode_grab(
1001	struct xfs_inode	*ip)
 
1002{
1003	ASSERT(rcu_read_lock_held());
1004
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1005	spin_lock(&ip->i_flags_lock);
1006	if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) ||
1007	    __xfs_iflags_test(ip, XFS_IRECLAIM)) {
1008		/* not a reclaim candidate. */
1009		spin_unlock(&ip->i_flags_lock);
1010		return false;
1011	}
1012	__xfs_iflags_set(ip, XFS_IRECLAIM);
1013	spin_unlock(&ip->i_flags_lock);
1014	return true;
1015}
1016
1017/*
1018 * Inode reclaim is non-blocking, so the default action if progress cannot be
1019 * made is to "requeue" the inode for reclaim by unlocking it and clearing the
1020 * XFS_IRECLAIM flag.  If we are in a shutdown state, we don't care about
1021 * blocking anymore and hence we can wait for the inode to be able to reclaim
1022 * it.
 
 
 
 
 
 
 
 
1023 *
1024 * We do no IO here - if callers require inodes to be cleaned they must push the
1025 * AIL first to trigger writeback of dirty inodes.  This enables writeback to be
1026 * done in the background in a non-blocking manner, and enables memory reclaim
1027 * to make progress without blocking.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1028 */
1029static void
1030xfs_reclaim_inode(
1031	struct xfs_inode	*ip,
1032	struct xfs_perag	*pag)
 
1033{
1034	xfs_ino_t		ino = ip->i_ino; /* for radix_tree_delete */
 
1035
1036	if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
1037		goto out;
1038	if (!xfs_iflock_nowait(ip))
1039		goto out_iunlock;
 
 
 
 
1040
1041	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
1042		xfs_iunpin_wait(ip);
1043		/* xfs_iflush_abort() drops the flush lock */
1044		xfs_iflush_abort(ip);
1045		goto reclaim;
1046	}
1047	if (xfs_ipincount(ip))
1048		goto out_ifunlock;
1049	if (!xfs_inode_clean(ip))
1050		goto out_ifunlock;
1051
1052	xfs_ifunlock(ip);
1053reclaim:
1054	ASSERT(!xfs_isiflocked(ip));
 
1055
1056	/*
1057	 * Because we use RCU freeing we need to ensure the inode always appears
1058	 * to be reclaimed with an invalid inode number when in the free state.
1059	 * We do this as early as possible under the ILOCK so that
1060	 * xfs_iflush_cluster() and xfs_ifree_cluster() can be guaranteed to
1061	 * detect races with us here. By doing this, we guarantee that once
1062	 * xfs_iflush_cluster() or xfs_ifree_cluster() has locked XFS_ILOCK that
1063	 * it will see either a valid inode that will serialise correctly, or it
1064	 * will see an invalid inode that it can skip.
1065	 */
1066	spin_lock(&ip->i_flags_lock);
1067	ip->i_flags = XFS_IRECLAIM;
1068	ip->i_ino = 0;
1069	spin_unlock(&ip->i_flags_lock);
1070
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1071	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1072
1073	XFS_STATS_INC(ip->i_mount, xs_ig_reclaims);
1074	/*
1075	 * Remove the inode from the per-AG radix tree.
1076	 *
1077	 * Because radix_tree_delete won't complain even if the item was never
1078	 * added to the tree assert that it's been there before to catch
1079	 * problems with the inode life time early on.
1080	 */
1081	spin_lock(&pag->pag_ici_lock);
1082	if (!radix_tree_delete(&pag->pag_ici_root,
1083				XFS_INO_TO_AGINO(ip->i_mount, ino)))
1084		ASSERT(0);
1085	xfs_perag_clear_reclaim_tag(pag);
1086	spin_unlock(&pag->pag_ici_lock);
1087
1088	/*
1089	 * Here we do an (almost) spurious inode lock in order to coordinate
1090	 * with inode cache radix tree lookups.  This is because the lookup
1091	 * can reference the inodes in the cache without taking references.
1092	 *
1093	 * We make that OK here by ensuring that we wait until the inode is
1094	 * unlocked after the lookup before we go ahead and free it.
1095	 */
1096	xfs_ilock(ip, XFS_ILOCK_EXCL);
1097	xfs_qm_dqdetach(ip);
1098	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1099	ASSERT(xfs_inode_clean(ip));
1100
1101	__xfs_inode_free(ip);
1102	return;
1103
1104out_ifunlock:
1105	xfs_ifunlock(ip);
1106out_iunlock:
1107	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1108out:
1109	xfs_iflags_clear(ip, XFS_IRECLAIM);
 
 
 
 
 
 
 
 
 
1110}
1111
1112/*
1113 * Walk the AGs and reclaim the inodes in them. Even if the filesystem is
1114 * corrupted, we still want to try to reclaim all the inodes. If we don't,
1115 * then a shut down during filesystem unmount reclaim walk leak all the
1116 * unreclaimed inodes.
1117 *
1118 * Returns non-zero if any AGs or inodes were skipped in the reclaim pass
1119 * so that callers that want to block until all dirty inodes are written back
1120 * and reclaimed can sanely loop.
1121 */
1122static void
1123xfs_reclaim_inodes_ag(
1124	struct xfs_mount	*mp,
 
1125	int			*nr_to_scan)
1126{
1127	struct xfs_perag	*pag;
1128	xfs_agnumber_t		ag = 0;
 
 
 
 
1129
 
 
 
1130	while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
1131		unsigned long	first_index = 0;
1132		int		done = 0;
1133		int		nr_found = 0;
1134
1135		ag = pag->pag_agno + 1;
1136
1137		first_index = READ_ONCE(pag->pag_ici_reclaim_cursor);
 
 
 
 
 
 
 
 
 
1138		do {
1139			struct xfs_inode *batch[XFS_LOOKUP_BATCH];
1140			int	i;
1141
1142			rcu_read_lock();
1143			nr_found = radix_tree_gang_lookup_tag(
1144					&pag->pag_ici_root,
1145					(void **)batch, first_index,
1146					XFS_LOOKUP_BATCH,
1147					XFS_ICI_RECLAIM_TAG);
1148			if (!nr_found) {
1149				done = 1;
1150				rcu_read_unlock();
1151				break;
1152			}
1153
1154			/*
1155			 * Grab the inodes before we drop the lock. if we found
1156			 * nothing, nr == 0 and the loop will be skipped.
1157			 */
1158			for (i = 0; i < nr_found; i++) {
1159				struct xfs_inode *ip = batch[i];
1160
1161				if (done || !xfs_reclaim_inode_grab(ip))
1162					batch[i] = NULL;
1163
1164				/*
1165				 * Update the index for the next lookup. Catch
1166				 * overflows into the next AG range which can
1167				 * occur if we have inodes in the last block of
1168				 * the AG and we are currently pointing to the
1169				 * last inode.
1170				 *
1171				 * Because we may see inodes that are from the
1172				 * wrong AG due to RCU freeing and
1173				 * reallocation, only update the index if it
1174				 * lies in this AG. It was a race that lead us
1175				 * to see this inode, so another lookup from
1176				 * the same index will not find it again.
1177				 */
1178				if (XFS_INO_TO_AGNO(mp, ip->i_ino) !=
1179								pag->pag_agno)
1180					continue;
1181				first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
1182				if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
1183					done = 1;
1184			}
1185
1186			/* unlock now we've grabbed the inodes. */
1187			rcu_read_unlock();
1188
1189			for (i = 0; i < nr_found; i++) {
1190				if (batch[i])
1191					xfs_reclaim_inode(batch[i], pag);
 
 
 
1192			}
1193
1194			*nr_to_scan -= XFS_LOOKUP_BATCH;
 
1195			cond_resched();
 
1196		} while (nr_found && !done && *nr_to_scan > 0);
1197
1198		if (done)
1199			first_index = 0;
1200		WRITE_ONCE(pag->pag_ici_reclaim_cursor, first_index);
 
 
1201		xfs_perag_put(pag);
1202	}
 
 
 
 
 
 
 
 
 
 
 
 
 
1203}
1204
1205void
1206xfs_reclaim_inodes(
1207	struct xfs_mount	*mp)
 
1208{
1209	int		nr_to_scan = INT_MAX;
1210
1211	while (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
1212		xfs_ail_push_all_sync(mp->m_ail);
1213		xfs_reclaim_inodes_ag(mp, &nr_to_scan);
1214	};
1215}
1216
1217/*
1218 * The shrinker infrastructure determines how many inodes we should scan for
1219 * reclaim. We want as many clean inodes ready to reclaim as possible, so we
1220 * push the AIL here. We also want to proactively free up memory if we can to
1221 * minimise the amount of work memory reclaim has to do so we kick the
1222 * background reclaim if it isn't already scheduled.
 
 
1223 */
1224long
1225xfs_reclaim_inodes_nr(
1226	struct xfs_mount	*mp,
1227	int			nr_to_scan)
1228{
1229	/* kick background reclaimer and push the AIL */
1230	xfs_reclaim_work_queue(mp);
1231	xfs_ail_push_all(mp->m_ail);
1232
1233	xfs_reclaim_inodes_ag(mp, &nr_to_scan);
1234	return 0;
1235}
1236
1237/*
1238 * Return the number of reclaimable inodes in the filesystem for
1239 * the shrinker to determine how much to reclaim.
1240 */
1241int
1242xfs_reclaim_inodes_count(
1243	struct xfs_mount	*mp)
1244{
1245	struct xfs_perag	*pag;
1246	xfs_agnumber_t		ag = 0;
1247	int			reclaimable = 0;
1248
1249	while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
1250		ag = pag->pag_agno + 1;
1251		reclaimable += pag->pag_ici_reclaimable;
1252		xfs_perag_put(pag);
1253	}
1254	return reclaimable;
1255}
1256
1257STATIC bool
1258xfs_inode_match_id(
1259	struct xfs_inode	*ip,
1260	struct xfs_eofblocks	*eofb)
1261{
1262	if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
1263	    !uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
1264		return false;
1265
1266	if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
1267	    !gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
1268		return false;
1269
1270	if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
1271	    ip->i_d.di_projid != eofb->eof_prid)
1272		return false;
1273
1274	return true;
1275}
1276
1277/*
1278 * A union-based inode filtering algorithm. Process the inode if any of the
1279 * criteria match. This is for global/internal scans only.
1280 */
1281STATIC bool
1282xfs_inode_match_id_union(
1283	struct xfs_inode	*ip,
1284	struct xfs_eofblocks	*eofb)
1285{
1286	if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
1287	    uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
1288		return true;
1289
1290	if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
1291	    gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
1292		return true;
1293
1294	if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
1295	    ip->i_d.di_projid == eofb->eof_prid)
1296		return true;
1297
1298	return false;
1299}
1300
1301/*
1302 * Is this inode @ip eligible for eof/cow block reclamation, given some
1303 * filtering parameters @eofb?  The inode is eligible if @eofb is null or
1304 * if the predicate functions match.
1305 */
1306static bool
1307xfs_inode_matches_eofb(
1308	struct xfs_inode	*ip,
1309	struct xfs_eofblocks	*eofb)
1310{
1311	bool			match;
1312
1313	if (!eofb)
1314		return true;
1315
1316	if (eofb->eof_flags & XFS_EOF_FLAGS_UNION)
1317		match = xfs_inode_match_id_union(ip, eofb);
1318	else
1319		match = xfs_inode_match_id(ip, eofb);
1320	if (!match)
1321		return false;
1322
1323	/* skip the inode if the file size is too small */
1324	if ((eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE) &&
1325	    XFS_ISIZE(ip) < eofb->eof_min_file_size)
1326		return false;
1327
1328	return true;
1329}
1330
1331/*
1332 * This is a fast pass over the inode cache to try to get reclaim moving on as
1333 * many inodes as possible in a short period of time. It kicks itself every few
1334 * seconds, as well as being kicked by the inode cache shrinker when memory
1335 * goes low.
1336 */
1337void
1338xfs_reclaim_worker(
1339	struct work_struct *work)
1340{
1341	struct xfs_mount *mp = container_of(to_delayed_work(work),
1342					struct xfs_mount, m_reclaim_work);
1343	int		nr_to_scan = INT_MAX;
1344
1345	xfs_reclaim_inodes_ag(mp, &nr_to_scan);
1346	xfs_reclaim_work_queue(mp);
1347}
1348
1349STATIC int
1350xfs_inode_free_eofblocks(
1351	struct xfs_inode	*ip,
 
1352	void			*args)
1353{
1354	struct xfs_eofblocks	*eofb = args;
1355	bool			wait;
1356	int			ret;
 
1357
1358	wait = eofb && (eofb->eof_flags & XFS_EOF_FLAGS_SYNC);
1359
1360	if (!xfs_can_free_eofblocks(ip, false)) {
1361		/* inode could be preallocated or append-only */
1362		trace_xfs_inode_free_eofblocks_invalid(ip);
1363		xfs_inode_clear_eofblocks_tag(ip);
1364		return 0;
1365	}
1366
1367	/*
1368	 * If the mapping is dirty the operation can block and wait for some
1369	 * time. Unless we are waiting, skip it.
1370	 */
1371	if (!wait && mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY))
 
1372		return 0;
1373
1374	if (!xfs_inode_matches_eofb(ip, eofb))
1375		return 0;
 
 
 
 
 
 
 
 
 
 
1376
1377	/*
1378	 * If the caller is waiting, return -EAGAIN to keep the background
1379	 * scanner moving and revisit the inode in a subsequent pass.
1380	 */
1381	if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1382		if (wait)
1383			return -EAGAIN;
1384		return 0;
1385	}
1386
1387	ret = xfs_free_eofblocks(ip);
1388	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
 
 
 
1389
1390	return ret;
1391}
1392
1393int
1394xfs_icache_free_eofblocks(
1395	struct xfs_mount	*mp,
1396	struct xfs_eofblocks	*eofb)
1397{
1398	return xfs_inode_walk(mp, 0, xfs_inode_free_eofblocks, eofb,
1399			XFS_ICI_EOFBLOCKS_TAG);
 
 
 
 
 
1400}
1401
1402/*
1403 * Run eofblocks scans on the quotas applicable to the inode. For inodes with
1404 * multiple quotas, we don't know exactly which quota caused an allocation
1405 * failure. We make a best effort by including each quota under low free space
1406 * conditions (less than 1% free space) in the scan.
1407 */
1408static int
1409__xfs_inode_free_quota_eofblocks(
1410	struct xfs_inode	*ip,
1411	int			(*execute)(struct xfs_mount *mp,
1412					   struct xfs_eofblocks	*eofb))
1413{
1414	int scan = 0;
1415	struct xfs_eofblocks eofb = {0};
1416	struct xfs_dquot *dq;
1417
 
 
1418	/*
1419	 * Run a sync scan to increase effectiveness and use the union filter to
 
 
1420	 * cover all applicable quotas in a single scan.
1421	 */
 
1422	eofb.eof_flags = XFS_EOF_FLAGS_UNION|XFS_EOF_FLAGS_SYNC;
1423
1424	if (XFS_IS_UQUOTA_ENFORCED(ip->i_mount)) {
1425		dq = xfs_inode_dquot(ip, XFS_DQTYPE_USER);
1426		if (dq && xfs_dquot_lowsp(dq)) {
1427			eofb.eof_uid = VFS_I(ip)->i_uid;
1428			eofb.eof_flags |= XFS_EOF_FLAGS_UID;
1429			scan = 1;
1430		}
1431	}
1432
1433	if (XFS_IS_GQUOTA_ENFORCED(ip->i_mount)) {
1434		dq = xfs_inode_dquot(ip, XFS_DQTYPE_GROUP);
1435		if (dq && xfs_dquot_lowsp(dq)) {
1436			eofb.eof_gid = VFS_I(ip)->i_gid;
1437			eofb.eof_flags |= XFS_EOF_FLAGS_GID;
1438			scan = 1;
1439		}
1440	}
1441
1442	if (scan)
1443		execute(ip->i_mount, &eofb);
1444
1445	return scan;
1446}
1447
1448int
1449xfs_inode_free_quota_eofblocks(
1450	struct xfs_inode *ip)
1451{
1452	return __xfs_inode_free_quota_eofblocks(ip, xfs_icache_free_eofblocks);
1453}
1454
1455static inline unsigned long
1456xfs_iflag_for_tag(
1457	int		tag)
1458{
1459	switch (tag) {
1460	case XFS_ICI_EOFBLOCKS_TAG:
1461		return XFS_IEOFBLOCKS;
1462	case XFS_ICI_COWBLOCKS_TAG:
1463		return XFS_ICOWBLOCKS;
1464	default:
1465		ASSERT(0);
1466		return 0;
1467	}
1468}
1469
1470static void
1471__xfs_inode_set_blocks_tag(
1472	xfs_inode_t	*ip,
1473	void		(*execute)(struct xfs_mount *mp),
1474	void		(*set_tp)(struct xfs_mount *mp, xfs_agnumber_t agno,
1475				  int error, unsigned long caller_ip),
1476	int		tag)
1477{
1478	struct xfs_mount *mp = ip->i_mount;
1479	struct xfs_perag *pag;
1480	int tagged;
1481
1482	/*
1483	 * Don't bother locking the AG and looking up in the radix trees
1484	 * if we already know that we have the tag set.
1485	 */
1486	if (ip->i_flags & xfs_iflag_for_tag(tag))
1487		return;
1488	spin_lock(&ip->i_flags_lock);
1489	ip->i_flags |= xfs_iflag_for_tag(tag);
1490	spin_unlock(&ip->i_flags_lock);
1491
1492	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
1493	spin_lock(&pag->pag_ici_lock);
 
1494
1495	tagged = radix_tree_tagged(&pag->pag_ici_root, tag);
 
1496	radix_tree_tag_set(&pag->pag_ici_root,
1497			   XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), tag);
 
1498	if (!tagged) {
1499		/* propagate the eofblocks tag up into the perag radix tree */
1500		spin_lock(&ip->i_mount->m_perag_lock);
1501		radix_tree_tag_set(&ip->i_mount->m_perag_tree,
1502				   XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
1503				   tag);
1504		spin_unlock(&ip->i_mount->m_perag_lock);
1505
1506		/* kick off background trimming */
1507		execute(ip->i_mount);
1508
1509		set_tp(ip->i_mount, pag->pag_agno, -1, _RET_IP_);
 
1510	}
1511
1512	spin_unlock(&pag->pag_ici_lock);
1513	xfs_perag_put(pag);
1514}
1515
1516void
1517xfs_inode_set_eofblocks_tag(
1518	xfs_inode_t	*ip)
1519{
1520	trace_xfs_inode_set_eofblocks_tag(ip);
1521	return __xfs_inode_set_blocks_tag(ip, xfs_queue_eofblocks,
1522			trace_xfs_perag_set_eofblocks,
1523			XFS_ICI_EOFBLOCKS_TAG);
1524}
1525
1526static void
1527__xfs_inode_clear_blocks_tag(
1528	xfs_inode_t	*ip,
1529	void		(*clear_tp)(struct xfs_mount *mp, xfs_agnumber_t agno,
1530				    int error, unsigned long caller_ip),
1531	int		tag)
1532{
1533	struct xfs_mount *mp = ip->i_mount;
1534	struct xfs_perag *pag;
1535
1536	spin_lock(&ip->i_flags_lock);
1537	ip->i_flags &= ~xfs_iflag_for_tag(tag);
1538	spin_unlock(&ip->i_flags_lock);
1539
1540	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
1541	spin_lock(&pag->pag_ici_lock);
 
1542
1543	radix_tree_tag_clear(&pag->pag_ici_root,
1544			     XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), tag);
1545	if (!radix_tree_tagged(&pag->pag_ici_root, tag)) {
 
1546		/* clear the eofblocks tag from the perag radix tree */
1547		spin_lock(&ip->i_mount->m_perag_lock);
1548		radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
1549				     XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
1550				     tag);
1551		spin_unlock(&ip->i_mount->m_perag_lock);
1552		clear_tp(ip->i_mount, pag->pag_agno, -1, _RET_IP_);
 
1553	}
1554
1555	spin_unlock(&pag->pag_ici_lock);
1556	xfs_perag_put(pag);
1557}
1558
1559void
1560xfs_inode_clear_eofblocks_tag(
1561	xfs_inode_t	*ip)
1562{
1563	trace_xfs_inode_clear_eofblocks_tag(ip);
1564	return __xfs_inode_clear_blocks_tag(ip,
1565			trace_xfs_perag_clear_eofblocks, XFS_ICI_EOFBLOCKS_TAG);
1566}
1567
1568/*
1569 * Set ourselves up to free CoW blocks from this file.  If it's already clean
1570 * then we can bail out quickly, but otherwise we must back off if the file
1571 * is undergoing some kind of write.
1572 */
1573static bool
1574xfs_prep_free_cowblocks(
1575	struct xfs_inode	*ip)
1576{
1577	/*
1578	 * Just clear the tag if we have an empty cow fork or none at all. It's
1579	 * possible the inode was fully unshared since it was originally tagged.
1580	 */
1581	if (!xfs_inode_has_cow_data(ip)) {
1582		trace_xfs_inode_free_cowblocks_invalid(ip);
1583		xfs_inode_clear_cowblocks_tag(ip);
1584		return false;
1585	}
1586
1587	/*
1588	 * If the mapping is dirty or under writeback we cannot touch the
1589	 * CoW fork.  Leave it alone if we're in the midst of a directio.
1590	 */
1591	if ((VFS_I(ip)->i_state & I_DIRTY_PAGES) ||
1592	    mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY) ||
1593	    mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_WRITEBACK) ||
1594	    atomic_read(&VFS_I(ip)->i_dio_count))
1595		return false;
1596
1597	return true;
1598}
1599
1600/*
1601 * Automatic CoW Reservation Freeing
1602 *
1603 * These functions automatically garbage collect leftover CoW reservations
1604 * that were made on behalf of a cowextsize hint when we start to run out
1605 * of quota or when the reservations sit around for too long.  If the file
1606 * has dirty pages or is undergoing writeback, its CoW reservations will
1607 * be retained.
1608 *
1609 * The actual garbage collection piggybacks off the same code that runs
1610 * the speculative EOF preallocation garbage collector.
1611 */
1612STATIC int
1613xfs_inode_free_cowblocks(
1614	struct xfs_inode	*ip,
1615	void			*args)
1616{
1617	struct xfs_eofblocks	*eofb = args;
1618	int			ret = 0;
1619
1620	if (!xfs_prep_free_cowblocks(ip))
1621		return 0;
1622
1623	if (!xfs_inode_matches_eofb(ip, eofb))
1624		return 0;
1625
1626	/* Free the CoW blocks */
1627	xfs_ilock(ip, XFS_IOLOCK_EXCL);
1628	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
1629
1630	/*
1631	 * Check again, nobody else should be able to dirty blocks or change
1632	 * the reflink iflag now that we have the first two locks held.
1633	 */
1634	if (xfs_prep_free_cowblocks(ip))
1635		ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false);
1636
1637	xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
1638	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1639
1640	return ret;
1641}
1642
1643int
1644xfs_icache_free_cowblocks(
1645	struct xfs_mount	*mp,
1646	struct xfs_eofblocks	*eofb)
1647{
1648	return xfs_inode_walk(mp, 0, xfs_inode_free_cowblocks, eofb,
1649			XFS_ICI_COWBLOCKS_TAG);
1650}
1651
1652int
1653xfs_inode_free_quota_cowblocks(
1654	struct xfs_inode *ip)
1655{
1656	return __xfs_inode_free_quota_eofblocks(ip, xfs_icache_free_cowblocks);
1657}
1658
1659void
1660xfs_inode_set_cowblocks_tag(
1661	xfs_inode_t	*ip)
1662{
1663	trace_xfs_inode_set_cowblocks_tag(ip);
1664	return __xfs_inode_set_blocks_tag(ip, xfs_queue_cowblocks,
1665			trace_xfs_perag_set_cowblocks,
1666			XFS_ICI_COWBLOCKS_TAG);
1667}
1668
1669void
1670xfs_inode_clear_cowblocks_tag(
1671	xfs_inode_t	*ip)
1672{
1673	trace_xfs_inode_clear_cowblocks_tag(ip);
1674	return __xfs_inode_clear_blocks_tag(ip,
1675			trace_xfs_perag_clear_cowblocks, XFS_ICI_COWBLOCKS_TAG);
1676}
1677
1678/* Disable post-EOF and CoW block auto-reclamation. */
1679void
1680xfs_stop_block_reaping(
1681	struct xfs_mount	*mp)
1682{
1683	cancel_delayed_work_sync(&mp->m_eofblocks_work);
1684	cancel_delayed_work_sync(&mp->m_cowblocks_work);
1685}
1686
1687/* Enable post-EOF and CoW block auto-reclamation. */
1688void
1689xfs_start_block_reaping(
1690	struct xfs_mount	*mp)
1691{
1692	xfs_queue_eofblocks(mp);
1693	xfs_queue_cowblocks(mp);
1694}