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v5.4
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   4 * All Rights Reserved.
 
 
 
 
 
 
 
 
 
 
 
 
 
   5 */
   6#include <linux/iversion.h>
   7
   8#include "xfs.h"
   9#include "xfs_fs.h"
  10#include "xfs_shared.h"
  11#include "xfs_format.h"
  12#include "xfs_log_format.h"
  13#include "xfs_trans_resv.h"
  14#include "xfs_sb.h"
  15#include "xfs_mount.h"
  16#include "xfs_defer.h"
  17#include "xfs_inode.h"
 
 
  18#include "xfs_dir2.h"
 
  19#include "xfs_attr.h"
  20#include "xfs_trans_space.h"
  21#include "xfs_trans.h"
  22#include "xfs_buf_item.h"
  23#include "xfs_inode_item.h"
  24#include "xfs_ialloc.h"
  25#include "xfs_bmap.h"
  26#include "xfs_bmap_util.h"
  27#include "xfs_errortag.h"
  28#include "xfs_error.h"
  29#include "xfs_quota.h"
  30#include "xfs_filestream.h"
 
  31#include "xfs_trace.h"
  32#include "xfs_icache.h"
  33#include "xfs_symlink.h"
  34#include "xfs_trans_priv.h"
  35#include "xfs_log.h"
  36#include "xfs_bmap_btree.h"
  37#include "xfs_reflink.h"
  38
  39kmem_zone_t *xfs_inode_zone;
  40
  41/*
  42 * Used in xfs_itruncate_extents().  This is the maximum number of extents
  43 * freed from a file in a single transaction.
  44 */
  45#define	XFS_ITRUNC_MAX_EXTENTS	2
  46
  47STATIC int xfs_iflush_int(struct xfs_inode *, struct xfs_buf *);
  48STATIC int xfs_iunlink(struct xfs_trans *, struct xfs_inode *);
  49STATIC int xfs_iunlink_remove(struct xfs_trans *, struct xfs_inode *);
  50
  51/*
  52 * helper function to extract extent size hint from inode
  53 */
  54xfs_extlen_t
  55xfs_get_extsz_hint(
  56	struct xfs_inode	*ip)
  57{
  58	if ((ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE) && ip->i_d.di_extsize)
  59		return ip->i_d.di_extsize;
  60	if (XFS_IS_REALTIME_INODE(ip))
  61		return ip->i_mount->m_sb.sb_rextsize;
  62	return 0;
  63}
  64
  65/*
  66 * Helper function to extract CoW extent size hint from inode.
  67 * Between the extent size hint and the CoW extent size hint, we
  68 * return the greater of the two.  If the value is zero (automatic),
  69 * use the default size.
  70 */
  71xfs_extlen_t
  72xfs_get_cowextsz_hint(
  73	struct xfs_inode	*ip)
  74{
  75	xfs_extlen_t		a, b;
  76
  77	a = 0;
  78	if (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
  79		a = ip->i_d.di_cowextsize;
  80	b = xfs_get_extsz_hint(ip);
  81
  82	a = max(a, b);
  83	if (a == 0)
  84		return XFS_DEFAULT_COWEXTSZ_HINT;
  85	return a;
  86}
  87
  88/*
  89 * These two are wrapper routines around the xfs_ilock() routine used to
  90 * centralize some grungy code.  They are used in places that wish to lock the
  91 * inode solely for reading the extents.  The reason these places can't just
  92 * call xfs_ilock(ip, XFS_ILOCK_SHARED) is that the inode lock also guards to
  93 * bringing in of the extents from disk for a file in b-tree format.  If the
  94 * inode is in b-tree format, then we need to lock the inode exclusively until
  95 * the extents are read in.  Locking it exclusively all the time would limit
  96 * our parallelism unnecessarily, though.  What we do instead is check to see
  97 * if the extents have been read in yet, and only lock the inode exclusively
  98 * if they have not.
  99 *
 100 * The functions return a value which should be given to the corresponding
 101 * xfs_iunlock() call.
 102 */
 103uint
 104xfs_ilock_data_map_shared(
 105	struct xfs_inode	*ip)
 106{
 107	uint			lock_mode = XFS_ILOCK_SHARED;
 108
 109	if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
 110	    (ip->i_df.if_flags & XFS_IFEXTENTS) == 0)
 111		lock_mode = XFS_ILOCK_EXCL;
 112	xfs_ilock(ip, lock_mode);
 113	return lock_mode;
 114}
 115
 116uint
 117xfs_ilock_attr_map_shared(
 118	struct xfs_inode	*ip)
 119{
 120	uint			lock_mode = XFS_ILOCK_SHARED;
 121
 122	if (ip->i_d.di_aformat == XFS_DINODE_FMT_BTREE &&
 123	    (ip->i_afp->if_flags & XFS_IFEXTENTS) == 0)
 124		lock_mode = XFS_ILOCK_EXCL;
 125	xfs_ilock(ip, lock_mode);
 126	return lock_mode;
 127}
 128
 129/*
 130 * In addition to i_rwsem in the VFS inode, the xfs inode contains 2
 131 * multi-reader locks: i_mmap_lock and the i_lock.  This routine allows
 132 * various combinations of the locks to be obtained.
 133 *
 134 * The 3 locks should always be ordered so that the IO lock is obtained first,
 135 * the mmap lock second and the ilock last in order to prevent deadlock.
 136 *
 137 * Basic locking order:
 138 *
 139 * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock
 140 *
 141 * mmap_sem locking order:
 142 *
 143 * i_rwsem -> page lock -> mmap_sem
 144 * mmap_sem -> i_mmap_lock -> page_lock
 145 *
 146 * The difference in mmap_sem locking order mean that we cannot hold the
 147 * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can
 148 * fault in pages during copy in/out (for buffered IO) or require the mmap_sem
 149 * in get_user_pages() to map the user pages into the kernel address space for
 150 * direct IO. Similarly the i_rwsem cannot be taken inside a page fault because
 151 * page faults already hold the mmap_sem.
 152 *
 153 * Hence to serialise fully against both syscall and mmap based IO, we need to
 154 * take both the i_rwsem and the i_mmap_lock. These locks should *only* be both
 155 * taken in places where we need to invalidate the page cache in a race
 156 * free manner (e.g. truncate, hole punch and other extent manipulation
 157 * functions).
 158 */
 159void
 160xfs_ilock(
 161	xfs_inode_t		*ip,
 162	uint			lock_flags)
 163{
 164	trace_xfs_ilock(ip, lock_flags, _RET_IP_);
 165
 166	/*
 167	 * You can't set both SHARED and EXCL for the same lock,
 168	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 169	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 170	 */
 171	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 172	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 173	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 174	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 175	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 176	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 177	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 178
 179	if (lock_flags & XFS_IOLOCK_EXCL) {
 180		down_write_nested(&VFS_I(ip)->i_rwsem,
 181				  XFS_IOLOCK_DEP(lock_flags));
 182	} else if (lock_flags & XFS_IOLOCK_SHARED) {
 183		down_read_nested(&VFS_I(ip)->i_rwsem,
 184				 XFS_IOLOCK_DEP(lock_flags));
 185	}
 186
 187	if (lock_flags & XFS_MMAPLOCK_EXCL)
 188		mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
 189	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 190		mraccess_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
 191
 192	if (lock_flags & XFS_ILOCK_EXCL)
 193		mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
 194	else if (lock_flags & XFS_ILOCK_SHARED)
 195		mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
 196}
 197
 198/*
 199 * This is just like xfs_ilock(), except that the caller
 200 * is guaranteed not to sleep.  It returns 1 if it gets
 201 * the requested locks and 0 otherwise.  If the IO lock is
 202 * obtained but the inode lock cannot be, then the IO lock
 203 * is dropped before returning.
 204 *
 205 * ip -- the inode being locked
 206 * lock_flags -- this parameter indicates the inode's locks to be
 207 *       to be locked.  See the comment for xfs_ilock() for a list
 208 *	 of valid values.
 209 */
 210int
 211xfs_ilock_nowait(
 212	xfs_inode_t		*ip,
 213	uint			lock_flags)
 214{
 215	trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
 216
 217	/*
 218	 * You can't set both SHARED and EXCL for the same lock,
 219	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 220	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 221	 */
 222	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 223	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 224	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 225	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 226	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 227	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 228	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 229
 230	if (lock_flags & XFS_IOLOCK_EXCL) {
 231		if (!down_write_trylock(&VFS_I(ip)->i_rwsem))
 232			goto out;
 233	} else if (lock_flags & XFS_IOLOCK_SHARED) {
 234		if (!down_read_trylock(&VFS_I(ip)->i_rwsem))
 235			goto out;
 236	}
 237
 238	if (lock_flags & XFS_MMAPLOCK_EXCL) {
 239		if (!mrtryupdate(&ip->i_mmaplock))
 240			goto out_undo_iolock;
 241	} else if (lock_flags & XFS_MMAPLOCK_SHARED) {
 242		if (!mrtryaccess(&ip->i_mmaplock))
 243			goto out_undo_iolock;
 244	}
 245
 246	if (lock_flags & XFS_ILOCK_EXCL) {
 247		if (!mrtryupdate(&ip->i_lock))
 248			goto out_undo_mmaplock;
 249	} else if (lock_flags & XFS_ILOCK_SHARED) {
 250		if (!mrtryaccess(&ip->i_lock))
 251			goto out_undo_mmaplock;
 252	}
 253	return 1;
 254
 255out_undo_mmaplock:
 256	if (lock_flags & XFS_MMAPLOCK_EXCL)
 257		mrunlock_excl(&ip->i_mmaplock);
 258	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 259		mrunlock_shared(&ip->i_mmaplock);
 260out_undo_iolock:
 261	if (lock_flags & XFS_IOLOCK_EXCL)
 262		up_write(&VFS_I(ip)->i_rwsem);
 263	else if (lock_flags & XFS_IOLOCK_SHARED)
 264		up_read(&VFS_I(ip)->i_rwsem);
 265out:
 266	return 0;
 267}
 268
 269/*
 270 * xfs_iunlock() is used to drop the inode locks acquired with
 271 * xfs_ilock() and xfs_ilock_nowait().  The caller must pass
 272 * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
 273 * that we know which locks to drop.
 274 *
 275 * ip -- the inode being unlocked
 276 * lock_flags -- this parameter indicates the inode's locks to be
 277 *       to be unlocked.  See the comment for xfs_ilock() for a list
 278 *	 of valid values for this parameter.
 279 *
 280 */
 281void
 282xfs_iunlock(
 283	xfs_inode_t		*ip,
 284	uint			lock_flags)
 285{
 286	/*
 287	 * You can't set both SHARED and EXCL for the same lock,
 288	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 289	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 290	 */
 291	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 292	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 293	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 294	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 295	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 296	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 297	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 298	ASSERT(lock_flags != 0);
 299
 300	if (lock_flags & XFS_IOLOCK_EXCL)
 301		up_write(&VFS_I(ip)->i_rwsem);
 302	else if (lock_flags & XFS_IOLOCK_SHARED)
 303		up_read(&VFS_I(ip)->i_rwsem);
 304
 305	if (lock_flags & XFS_MMAPLOCK_EXCL)
 306		mrunlock_excl(&ip->i_mmaplock);
 307	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 308		mrunlock_shared(&ip->i_mmaplock);
 309
 310	if (lock_flags & XFS_ILOCK_EXCL)
 311		mrunlock_excl(&ip->i_lock);
 312	else if (lock_flags & XFS_ILOCK_SHARED)
 313		mrunlock_shared(&ip->i_lock);
 314
 315	trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
 316}
 317
 318/*
 319 * give up write locks.  the i/o lock cannot be held nested
 320 * if it is being demoted.
 321 */
 322void
 323xfs_ilock_demote(
 324	xfs_inode_t		*ip,
 325	uint			lock_flags)
 326{
 327	ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL));
 328	ASSERT((lock_flags &
 329		~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
 330
 331	if (lock_flags & XFS_ILOCK_EXCL)
 332		mrdemote(&ip->i_lock);
 333	if (lock_flags & XFS_MMAPLOCK_EXCL)
 334		mrdemote(&ip->i_mmaplock);
 335	if (lock_flags & XFS_IOLOCK_EXCL)
 336		downgrade_write(&VFS_I(ip)->i_rwsem);
 337
 338	trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
 339}
 340
 341#if defined(DEBUG) || defined(XFS_WARN)
 342int
 343xfs_isilocked(
 344	xfs_inode_t		*ip,
 345	uint			lock_flags)
 346{
 347	if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
 348		if (!(lock_flags & XFS_ILOCK_SHARED))
 349			return !!ip->i_lock.mr_writer;
 350		return rwsem_is_locked(&ip->i_lock.mr_lock);
 351	}
 352
 353	if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) {
 354		if (!(lock_flags & XFS_MMAPLOCK_SHARED))
 355			return !!ip->i_mmaplock.mr_writer;
 356		return rwsem_is_locked(&ip->i_mmaplock.mr_lock);
 357	}
 358
 359	if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
 360		if (!(lock_flags & XFS_IOLOCK_SHARED))
 361			return !debug_locks ||
 362				lockdep_is_held_type(&VFS_I(ip)->i_rwsem, 0);
 363		return rwsem_is_locked(&VFS_I(ip)->i_rwsem);
 364	}
 365
 366	ASSERT(0);
 367	return 0;
 368}
 369#endif
 370
 
 
 
 
 
 
 
 
 371/*
 372 * xfs_lockdep_subclass_ok() is only used in an ASSERT, so is only called when
 373 * DEBUG or XFS_WARN is set. And MAX_LOCKDEP_SUBCLASSES is then only defined
 374 * when CONFIG_LOCKDEP is set. Hence the complex define below to avoid build
 375 * errors and warnings.
 376 */
 377#if (defined(DEBUG) || defined(XFS_WARN)) && defined(CONFIG_LOCKDEP)
 378static bool
 379xfs_lockdep_subclass_ok(
 380	int subclass)
 381{
 382	return subclass < MAX_LOCKDEP_SUBCLASSES;
 383}
 384#else
 385#define xfs_lockdep_subclass_ok(subclass)	(true)
 386#endif
 387
 388/*
 389 * Bump the subclass so xfs_lock_inodes() acquires each lock with a different
 390 * value. This can be called for any type of inode lock combination, including
 391 * parent locking. Care must be taken to ensure we don't overrun the subclass
 392 * storage fields in the class mask we build.
 393 */
 394static inline int
 395xfs_lock_inumorder(int lock_mode, int subclass)
 396{
 397	int	class = 0;
 398
 399	ASSERT(!(lock_mode & (XFS_ILOCK_PARENT | XFS_ILOCK_RTBITMAP |
 400			      XFS_ILOCK_RTSUM)));
 401	ASSERT(xfs_lockdep_subclass_ok(subclass));
 402
 403	if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) {
 404		ASSERT(subclass <= XFS_IOLOCK_MAX_SUBCLASS);
 405		class += subclass << XFS_IOLOCK_SHIFT;
 406	}
 407
 408	if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) {
 409		ASSERT(subclass <= XFS_MMAPLOCK_MAX_SUBCLASS);
 410		class += subclass << XFS_MMAPLOCK_SHIFT;
 411	}
 412
 413	if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) {
 414		ASSERT(subclass <= XFS_ILOCK_MAX_SUBCLASS);
 415		class += subclass << XFS_ILOCK_SHIFT;
 416	}
 417
 418	return (lock_mode & ~XFS_LOCK_SUBCLASS_MASK) | class;
 419}
 420
 421/*
 422 * The following routine will lock n inodes in exclusive mode.  We assume the
 423 * caller calls us with the inodes in i_ino order.
 424 *
 425 * We need to detect deadlock where an inode that we lock is in the AIL and we
 426 * start waiting for another inode that is locked by a thread in a long running
 427 * transaction (such as truncate). This can result in deadlock since the long
 428 * running trans might need to wait for the inode we just locked in order to
 429 * push the tail and free space in the log.
 430 *
 431 * xfs_lock_inodes() can only be used to lock one type of lock at a time -
 432 * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
 433 * lock more than one at a time, lockdep will report false positives saying we
 434 * have violated locking orders.
 435 */
 436static void
 437xfs_lock_inodes(
 438	struct xfs_inode	**ips,
 439	int			inodes,
 440	uint			lock_mode)
 441{
 442	int			attempts = 0, i, j, try_lock;
 443	struct xfs_log_item	*lp;
 444
 445	/*
 446	 * Currently supports between 2 and 5 inodes with exclusive locking.  We
 447	 * support an arbitrary depth of locking here, but absolute limits on
 448	 * inodes depend on the the type of locking and the limits placed by
 449	 * lockdep annotations in xfs_lock_inumorder.  These are all checked by
 450	 * the asserts.
 451	 */
 452	ASSERT(ips && inodes >= 2 && inodes <= 5);
 453	ASSERT(lock_mode & (XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL |
 454			    XFS_ILOCK_EXCL));
 455	ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED | XFS_MMAPLOCK_SHARED |
 456			      XFS_ILOCK_SHARED)));
 457	ASSERT(!(lock_mode & XFS_MMAPLOCK_EXCL) ||
 458		inodes <= XFS_MMAPLOCK_MAX_SUBCLASS + 1);
 459	ASSERT(!(lock_mode & XFS_ILOCK_EXCL) ||
 460		inodes <= XFS_ILOCK_MAX_SUBCLASS + 1);
 461
 462	if (lock_mode & XFS_IOLOCK_EXCL) {
 463		ASSERT(!(lock_mode & (XFS_MMAPLOCK_EXCL | XFS_ILOCK_EXCL)));
 464	} else if (lock_mode & XFS_MMAPLOCK_EXCL)
 465		ASSERT(!(lock_mode & XFS_ILOCK_EXCL));
 466
 467	try_lock = 0;
 468	i = 0;
 469again:
 470	for (; i < inodes; i++) {
 471		ASSERT(ips[i]);
 472
 473		if (i && (ips[i] == ips[i - 1]))	/* Already locked */
 474			continue;
 475
 476		/*
 477		 * If try_lock is not set yet, make sure all locked inodes are
 478		 * not in the AIL.  If any are, set try_lock to be used later.
 479		 */
 480		if (!try_lock) {
 481			for (j = (i - 1); j >= 0 && !try_lock; j--) {
 482				lp = &ips[j]->i_itemp->ili_item;
 483				if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags))
 484					try_lock++;
 485			}
 486		}
 487
 488		/*
 489		 * If any of the previous locks we have locked is in the AIL,
 490		 * we must TRY to get the second and subsequent locks. If
 491		 * we can't get any, we must release all we have
 492		 * and try again.
 493		 */
 494		if (!try_lock) {
 495			xfs_ilock(ips[i], xfs_lock_inumorder(lock_mode, i));
 496			continue;
 497		}
 498
 499		/* try_lock means we have an inode locked that is in the AIL. */
 500		ASSERT(i != 0);
 501		if (xfs_ilock_nowait(ips[i], xfs_lock_inumorder(lock_mode, i)))
 502			continue;
 503
 504		/*
 505		 * Unlock all previous guys and try again.  xfs_iunlock will try
 506		 * to push the tail if the inode is in the AIL.
 507		 */
 508		attempts++;
 509		for (j = i - 1; j >= 0; j--) {
 510			/*
 511			 * Check to see if we've already unlocked this one.  Not
 512			 * the first one going back, and the inode ptr is the
 513			 * same.
 514			 */
 515			if (j != (i - 1) && ips[j] == ips[j + 1])
 516				continue;
 517
 518			xfs_iunlock(ips[j], lock_mode);
 519		}
 520
 521		if ((attempts % 5) == 0) {
 522			delay(1); /* Don't just spin the CPU */
 
 
 
 523		}
 524		i = 0;
 525		try_lock = 0;
 526		goto again;
 527	}
 
 
 
 
 
 
 
 
 
 
 528}
 529
 530/*
 531 * xfs_lock_two_inodes() can only be used to lock one type of lock at a time -
 532 * the mmaplock or the ilock, but not more than one type at a time. If we lock
 533 * more than one at a time, lockdep will report false positives saying we have
 534 * violated locking orders.  The iolock must be double-locked separately since
 535 * we use i_rwsem for that.  We now support taking one lock EXCL and the other
 536 * SHARED.
 537 */
 538void
 539xfs_lock_two_inodes(
 540	struct xfs_inode	*ip0,
 541	uint			ip0_mode,
 542	struct xfs_inode	*ip1,
 543	uint			ip1_mode)
 544{
 545	struct xfs_inode	*temp;
 546	uint			mode_temp;
 547	int			attempts = 0;
 548	struct xfs_log_item	*lp;
 549
 550	ASSERT(hweight32(ip0_mode) == 1);
 551	ASSERT(hweight32(ip1_mode) == 1);
 552	ASSERT(!(ip0_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
 553	ASSERT(!(ip1_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
 554	ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
 555	       !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
 556	ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
 557	       !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
 558	ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
 559	       !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
 560	ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
 561	       !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
 562
 563	ASSERT(ip0->i_ino != ip1->i_ino);
 564
 565	if (ip0->i_ino > ip1->i_ino) {
 566		temp = ip0;
 567		ip0 = ip1;
 568		ip1 = temp;
 569		mode_temp = ip0_mode;
 570		ip0_mode = ip1_mode;
 571		ip1_mode = mode_temp;
 572	}
 573
 574 again:
 575	xfs_ilock(ip0, xfs_lock_inumorder(ip0_mode, 0));
 576
 577	/*
 578	 * If the first lock we have locked is in the AIL, we must TRY to get
 579	 * the second lock. If we can't get it, we must release the first one
 580	 * and try again.
 581	 */
 582	lp = &ip0->i_itemp->ili_item;
 583	if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
 584		if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(ip1_mode, 1))) {
 585			xfs_iunlock(ip0, ip0_mode);
 586			if ((++attempts % 5) == 0)
 587				delay(1); /* Don't just spin the CPU */
 588			goto again;
 589		}
 590	} else {
 591		xfs_ilock(ip1, xfs_lock_inumorder(ip1_mode, 1));
 592	}
 593}
 594
 
 595void
 596__xfs_iflock(
 597	struct xfs_inode	*ip)
 598{
 599	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IFLOCK_BIT);
 600	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IFLOCK_BIT);
 601
 602	do {
 603		prepare_to_wait_exclusive(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
 604		if (xfs_isiflocked(ip))
 605			io_schedule();
 606	} while (!xfs_iflock_nowait(ip));
 607
 608	finish_wait(wq, &wait.wq_entry);
 609}
 610
 611STATIC uint
 612_xfs_dic2xflags(
 613	uint16_t		di_flags,
 614	uint64_t		di_flags2,
 615	bool			has_attr)
 616{
 617	uint			flags = 0;
 618
 619	if (di_flags & XFS_DIFLAG_ANY) {
 620		if (di_flags & XFS_DIFLAG_REALTIME)
 621			flags |= FS_XFLAG_REALTIME;
 622		if (di_flags & XFS_DIFLAG_PREALLOC)
 623			flags |= FS_XFLAG_PREALLOC;
 624		if (di_flags & XFS_DIFLAG_IMMUTABLE)
 625			flags |= FS_XFLAG_IMMUTABLE;
 626		if (di_flags & XFS_DIFLAG_APPEND)
 627			flags |= FS_XFLAG_APPEND;
 628		if (di_flags & XFS_DIFLAG_SYNC)
 629			flags |= FS_XFLAG_SYNC;
 630		if (di_flags & XFS_DIFLAG_NOATIME)
 631			flags |= FS_XFLAG_NOATIME;
 632		if (di_flags & XFS_DIFLAG_NODUMP)
 633			flags |= FS_XFLAG_NODUMP;
 634		if (di_flags & XFS_DIFLAG_RTINHERIT)
 635			flags |= FS_XFLAG_RTINHERIT;
 636		if (di_flags & XFS_DIFLAG_PROJINHERIT)
 637			flags |= FS_XFLAG_PROJINHERIT;
 638		if (di_flags & XFS_DIFLAG_NOSYMLINKS)
 639			flags |= FS_XFLAG_NOSYMLINKS;
 640		if (di_flags & XFS_DIFLAG_EXTSIZE)
 641			flags |= FS_XFLAG_EXTSIZE;
 642		if (di_flags & XFS_DIFLAG_EXTSZINHERIT)
 643			flags |= FS_XFLAG_EXTSZINHERIT;
 644		if (di_flags & XFS_DIFLAG_NODEFRAG)
 645			flags |= FS_XFLAG_NODEFRAG;
 646		if (di_flags & XFS_DIFLAG_FILESTREAM)
 647			flags |= FS_XFLAG_FILESTREAM;
 648	}
 649
 650	if (di_flags2 & XFS_DIFLAG2_ANY) {
 651		if (di_flags2 & XFS_DIFLAG2_DAX)
 652			flags |= FS_XFLAG_DAX;
 653		if (di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
 654			flags |= FS_XFLAG_COWEXTSIZE;
 655	}
 656
 657	if (has_attr)
 658		flags |= FS_XFLAG_HASATTR;
 659
 660	return flags;
 661}
 662
 663uint
 664xfs_ip2xflags(
 665	struct xfs_inode	*ip)
 666{
 667	struct xfs_icdinode	*dic = &ip->i_d;
 668
 669	return _xfs_dic2xflags(dic->di_flags, dic->di_flags2, XFS_IFORK_Q(ip));
 670}
 671
 672/*
 673 * Lookups up an inode from "name". If ci_name is not NULL, then a CI match
 674 * is allowed, otherwise it has to be an exact match. If a CI match is found,
 675 * ci_name->name will point to a the actual name (caller must free) or
 676 * will be set to NULL if an exact match is found.
 677 */
 678int
 679xfs_lookup(
 680	xfs_inode_t		*dp,
 681	struct xfs_name		*name,
 682	xfs_inode_t		**ipp,
 683	struct xfs_name		*ci_name)
 684{
 685	xfs_ino_t		inum;
 686	int			error;
 687
 688	trace_xfs_lookup(dp, name);
 689
 690	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
 691		return -EIO;
 692
 693	error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
 694	if (error)
 695		goto out_unlock;
 696
 697	error = xfs_iget(dp->i_mount, NULL, inum, 0, 0, ipp);
 698	if (error)
 699		goto out_free_name;
 700
 701	return 0;
 702
 703out_free_name:
 704	if (ci_name)
 705		kmem_free(ci_name->name);
 706out_unlock:
 707	*ipp = NULL;
 708	return error;
 709}
 710
 711/*
 712 * Allocate an inode on disk and return a copy of its in-core version.
 713 * The in-core inode is locked exclusively.  Set mode, nlink, and rdev
 714 * appropriately within the inode.  The uid and gid for the inode are
 715 * set according to the contents of the given cred structure.
 716 *
 717 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
 718 * has a free inode available, call xfs_iget() to obtain the in-core
 719 * version of the allocated inode.  Finally, fill in the inode and
 720 * log its initial contents.  In this case, ialloc_context would be
 721 * set to NULL.
 722 *
 723 * If xfs_dialloc() does not have an available inode, it will replenish
 724 * its supply by doing an allocation. Since we can only do one
 725 * allocation within a transaction without deadlocks, we must commit
 726 * the current transaction before returning the inode itself.
 727 * In this case, therefore, we will set ialloc_context and return.
 728 * The caller should then commit the current transaction, start a new
 729 * transaction, and call xfs_ialloc() again to actually get the inode.
 730 *
 731 * To ensure that some other process does not grab the inode that
 732 * was allocated during the first call to xfs_ialloc(), this routine
 733 * also returns the [locked] bp pointing to the head of the freelist
 734 * as ialloc_context.  The caller should hold this buffer across
 735 * the commit and pass it back into this routine on the second call.
 736 *
 737 * If we are allocating quota inodes, we do not have a parent inode
 738 * to attach to or associate with (i.e. pip == NULL) because they
 739 * are not linked into the directory structure - they are attached
 740 * directly to the superblock - and so have no parent.
 741 */
 742static int
 743xfs_ialloc(
 744	xfs_trans_t	*tp,
 745	xfs_inode_t	*pip,
 746	umode_t		mode,
 747	xfs_nlink_t	nlink,
 748	dev_t		rdev,
 749	prid_t		prid,
 
 750	xfs_buf_t	**ialloc_context,
 751	xfs_inode_t	**ipp)
 752{
 753	struct xfs_mount *mp = tp->t_mountp;
 754	xfs_ino_t	ino;
 755	xfs_inode_t	*ip;
 756	uint		flags;
 757	int		error;
 758	struct timespec64 tv;
 759	struct inode	*inode;
 760
 761	/*
 762	 * Call the space management code to pick
 763	 * the on-disk inode to be allocated.
 764	 */
 765	error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode,
 766			    ialloc_context, &ino);
 767	if (error)
 768		return error;
 769	if (*ialloc_context || ino == NULLFSINO) {
 770		*ipp = NULL;
 771		return 0;
 772	}
 773	ASSERT(*ialloc_context == NULL);
 774
 775	/*
 776	 * Protect against obviously corrupt allocation btree records. Later
 777	 * xfs_iget checks will catch re-allocation of other active in-memory
 778	 * and on-disk inodes. If we don't catch reallocating the parent inode
 779	 * here we will deadlock in xfs_iget() so we have to do these checks
 780	 * first.
 781	 */
 782	if ((pip && ino == pip->i_ino) || !xfs_verify_dir_ino(mp, ino)) {
 783		xfs_alert(mp, "Allocated a known in-use inode 0x%llx!", ino);
 784		return -EFSCORRUPTED;
 785	}
 786
 787	/*
 788	 * Get the in-core inode with the lock held exclusively.
 789	 * This is because we're setting fields here we need
 790	 * to prevent others from looking at until we're done.
 791	 */
 792	error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE,
 793			 XFS_ILOCK_EXCL, &ip);
 794	if (error)
 795		return error;
 796	ASSERT(ip != NULL);
 797	inode = VFS_I(ip);
 798
 799	/*
 800	 * We always convert v1 inodes to v2 now - we only support filesystems
 801	 * with >= v2 inode capability, so there is no reason for ever leaving
 802	 * an inode in v1 format.
 803	 */
 804	if (ip->i_d.di_version == 1)
 805		ip->i_d.di_version = 2;
 806
 807	inode->i_mode = mode;
 808	set_nlink(inode, nlink);
 809	ip->i_d.di_uid = xfs_kuid_to_uid(current_fsuid());
 810	ip->i_d.di_gid = xfs_kgid_to_gid(current_fsgid());
 811	inode->i_rdev = rdev;
 812	xfs_set_projid(ip, prid);
 813
 814	if (pip && XFS_INHERIT_GID(pip)) {
 815		ip->i_d.di_gid = pip->i_d.di_gid;
 816		if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode))
 817			inode->i_mode |= S_ISGID;
 818	}
 819
 820	/*
 821	 * If the group ID of the new file does not match the effective group
 822	 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
 823	 * (and only if the irix_sgid_inherit compatibility variable is set).
 824	 */
 825	if ((irix_sgid_inherit) &&
 826	    (inode->i_mode & S_ISGID) &&
 827	    (!in_group_p(xfs_gid_to_kgid(ip->i_d.di_gid))))
 828		inode->i_mode &= ~S_ISGID;
 829
 830	ip->i_d.di_size = 0;
 831	ip->i_d.di_nextents = 0;
 832	ASSERT(ip->i_d.di_nblocks == 0);
 833
 834	tv = current_time(inode);
 835	inode->i_mtime = tv;
 836	inode->i_atime = tv;
 837	inode->i_ctime = tv;
 838
 839	ip->i_d.di_extsize = 0;
 840	ip->i_d.di_dmevmask = 0;
 841	ip->i_d.di_dmstate = 0;
 842	ip->i_d.di_flags = 0;
 843
 844	if (ip->i_d.di_version == 3) {
 845		inode_set_iversion(inode, 1);
 846		ip->i_d.di_flags2 = 0;
 847		ip->i_d.di_cowextsize = 0;
 848		ip->i_d.di_crtime.t_sec = (int32_t)tv.tv_sec;
 849		ip->i_d.di_crtime.t_nsec = (int32_t)tv.tv_nsec;
 850	}
 851
 852
 853	flags = XFS_ILOG_CORE;
 854	switch (mode & S_IFMT) {
 855	case S_IFIFO:
 856	case S_IFCHR:
 857	case S_IFBLK:
 858	case S_IFSOCK:
 859		ip->i_d.di_format = XFS_DINODE_FMT_DEV;
 
 860		ip->i_df.if_flags = 0;
 861		flags |= XFS_ILOG_DEV;
 862		break;
 863	case S_IFREG:
 864	case S_IFDIR:
 865		if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
 
 866			uint		di_flags = 0;
 867
 868			if (S_ISDIR(mode)) {
 869				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
 870					di_flags |= XFS_DIFLAG_RTINHERIT;
 871				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
 872					di_flags |= XFS_DIFLAG_EXTSZINHERIT;
 873					ip->i_d.di_extsize = pip->i_d.di_extsize;
 874				}
 875				if (pip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
 876					di_flags |= XFS_DIFLAG_PROJINHERIT;
 877			} else if (S_ISREG(mode)) {
 878				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
 879					di_flags |= XFS_DIFLAG_REALTIME;
 880				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
 881					di_flags |= XFS_DIFLAG_EXTSIZE;
 882					ip->i_d.di_extsize = pip->i_d.di_extsize;
 883				}
 884			}
 885			if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
 886			    xfs_inherit_noatime)
 887				di_flags |= XFS_DIFLAG_NOATIME;
 888			if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
 889			    xfs_inherit_nodump)
 890				di_flags |= XFS_DIFLAG_NODUMP;
 891			if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
 892			    xfs_inherit_sync)
 893				di_flags |= XFS_DIFLAG_SYNC;
 894			if ((pip->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) &&
 895			    xfs_inherit_nosymlinks)
 896				di_flags |= XFS_DIFLAG_NOSYMLINKS;
 897			if ((pip->i_d.di_flags & XFS_DIFLAG_NODEFRAG) &&
 898			    xfs_inherit_nodefrag)
 899				di_flags |= XFS_DIFLAG_NODEFRAG;
 900			if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
 901				di_flags |= XFS_DIFLAG_FILESTREAM;
 
 
 902
 903			ip->i_d.di_flags |= di_flags;
 
 904		}
 905		if (pip &&
 906		    (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY) &&
 907		    pip->i_d.di_version == 3 &&
 908		    ip->i_d.di_version == 3) {
 909			uint64_t	di_flags2 = 0;
 910
 911			if (pip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) {
 912				di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
 913				ip->i_d.di_cowextsize = pip->i_d.di_cowextsize;
 914			}
 915			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
 916				di_flags2 |= XFS_DIFLAG2_DAX;
 917
 918			ip->i_d.di_flags2 |= di_flags2;
 919		}
 920		/* FALLTHROUGH */
 921	case S_IFLNK:
 922		ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
 923		ip->i_df.if_flags = XFS_IFEXTENTS;
 924		ip->i_df.if_bytes = 0;
 925		ip->i_df.if_u1.if_root = NULL;
 926		break;
 927	default:
 928		ASSERT(0);
 929	}
 930	/*
 931	 * Attribute fork settings for new inode.
 932	 */
 933	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
 934	ip->i_d.di_anextents = 0;
 935
 936	/*
 937	 * Log the new values stuffed into the inode.
 938	 */
 939	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 940	xfs_trans_log_inode(tp, ip, flags);
 941
 942	/* now that we have an i_mode we can setup the inode structure */
 943	xfs_setup_inode(ip);
 944
 945	*ipp = ip;
 946	return 0;
 947}
 948
 949/*
 950 * Allocates a new inode from disk and return a pointer to the
 951 * incore copy. This routine will internally commit the current
 952 * transaction and allocate a new one if the Space Manager needed
 953 * to do an allocation to replenish the inode free-list.
 954 *
 955 * This routine is designed to be called from xfs_create and
 956 * xfs_create_dir.
 957 *
 958 */
 959int
 960xfs_dir_ialloc(
 961	xfs_trans_t	**tpp,		/* input: current transaction;
 962					   output: may be a new transaction. */
 963	xfs_inode_t	*dp,		/* directory within whose allocate
 964					   the inode. */
 965	umode_t		mode,
 966	xfs_nlink_t	nlink,
 967	dev_t		rdev,
 968	prid_t		prid,		/* project id */
 969	xfs_inode_t	**ipp)		/* pointer to inode; it will be
 
 970					   locked. */
 
 
 971{
 972	xfs_trans_t	*tp;
 973	xfs_inode_t	*ip;
 974	xfs_buf_t	*ialloc_context = NULL;
 975	int		code;
 976	void		*dqinfo;
 977	uint		tflags;
 978
 979	tp = *tpp;
 980	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
 981
 982	/*
 983	 * xfs_ialloc will return a pointer to an incore inode if
 984	 * the Space Manager has an available inode on the free
 985	 * list. Otherwise, it will do an allocation and replenish
 986	 * the freelist.  Since we can only do one allocation per
 987	 * transaction without deadlocks, we will need to commit the
 988	 * current transaction and start a new one.  We will then
 989	 * need to call xfs_ialloc again to get the inode.
 990	 *
 991	 * If xfs_ialloc did an allocation to replenish the freelist,
 992	 * it returns the bp containing the head of the freelist as
 993	 * ialloc_context. We will hold a lock on it across the
 994	 * transaction commit so that no other process can steal
 995	 * the inode(s) that we've just allocated.
 996	 */
 997	code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, &ialloc_context,
 998			&ip);
 999
1000	/*
1001	 * Return an error if we were unable to allocate a new inode.
1002	 * This should only happen if we run out of space on disk or
1003	 * encounter a disk error.
1004	 */
1005	if (code) {
1006		*ipp = NULL;
1007		return code;
1008	}
1009	if (!ialloc_context && !ip) {
1010		*ipp = NULL;
1011		return -ENOSPC;
1012	}
1013
1014	/*
1015	 * If the AGI buffer is non-NULL, then we were unable to get an
1016	 * inode in one operation.  We need to commit the current
1017	 * transaction and call xfs_ialloc() again.  It is guaranteed
1018	 * to succeed the second time.
1019	 */
1020	if (ialloc_context) {
1021		/*
1022		 * Normally, xfs_trans_commit releases all the locks.
1023		 * We call bhold to hang on to the ialloc_context across
1024		 * the commit.  Holding this buffer prevents any other
1025		 * processes from doing any allocations in this
1026		 * allocation group.
1027		 */
1028		xfs_trans_bhold(tp, ialloc_context);
1029
1030		/*
1031		 * We want the quota changes to be associated with the next
1032		 * transaction, NOT this one. So, detach the dqinfo from this
1033		 * and attach it to the next transaction.
1034		 */
1035		dqinfo = NULL;
1036		tflags = 0;
1037		if (tp->t_dqinfo) {
1038			dqinfo = (void *)tp->t_dqinfo;
1039			tp->t_dqinfo = NULL;
1040			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
1041			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
1042		}
1043
1044		code = xfs_trans_roll(&tp);
 
 
1045
1046		/*
1047		 * Re-attach the quota info that we detached from prev trx.
1048		 */
1049		if (dqinfo) {
1050			tp->t_dqinfo = dqinfo;
1051			tp->t_flags |= tflags;
1052		}
1053
1054		if (code) {
1055			xfs_buf_relse(ialloc_context);
1056			*tpp = tp;
1057			*ipp = NULL;
1058			return code;
1059		}
1060		xfs_trans_bjoin(tp, ialloc_context);
1061
1062		/*
1063		 * Call ialloc again. Since we've locked out all
1064		 * other allocations in this allocation group,
1065		 * this call should always succeed.
1066		 */
1067		code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
1068				  &ialloc_context, &ip);
1069
1070		/*
1071		 * If we get an error at this point, return to the caller
1072		 * so that the current transaction can be aborted.
1073		 */
1074		if (code) {
1075			*tpp = tp;
1076			*ipp = NULL;
1077			return code;
1078		}
1079		ASSERT(!ialloc_context && ip);
1080
 
 
 
1081	}
1082
1083	*ipp = ip;
1084	*tpp = tp;
1085
1086	return 0;
1087}
1088
1089/*
1090 * Decrement the link count on an inode & log the change.  If this causes the
1091 * link count to go to zero, move the inode to AGI unlinked list so that it can
1092 * be freed when the last active reference goes away via xfs_inactive().
1093 */
1094static int			/* error */
1095xfs_droplink(
1096	xfs_trans_t *tp,
1097	xfs_inode_t *ip)
1098{
1099	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1100
1101	drop_nlink(VFS_I(ip));
1102	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1103
1104	if (VFS_I(ip)->i_nlink)
1105		return 0;
1106
1107	return xfs_iunlink(tp, ip);
1108}
1109
1110/*
1111 * Increment the link count on an inode & log the change.
1112 */
1113static void
1114xfs_bumplink(
1115	xfs_trans_t *tp,
1116	xfs_inode_t *ip)
1117{
1118	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1119
1120	ASSERT(ip->i_d.di_version > 1);
1121	inc_nlink(VFS_I(ip));
1122	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 
1123}
1124
1125int
1126xfs_create(
1127	xfs_inode_t		*dp,
1128	struct xfs_name		*name,
1129	umode_t			mode,
1130	dev_t			rdev,
1131	xfs_inode_t		**ipp)
1132{
1133	int			is_dir = S_ISDIR(mode);
1134	struct xfs_mount	*mp = dp->i_mount;
1135	struct xfs_inode	*ip = NULL;
1136	struct xfs_trans	*tp = NULL;
1137	int			error;
 
 
1138	bool                    unlock_dp_on_error = false;
1139	prid_t			prid;
1140	struct xfs_dquot	*udqp = NULL;
1141	struct xfs_dquot	*gdqp = NULL;
1142	struct xfs_dquot	*pdqp = NULL;
1143	struct xfs_trans_res	*tres;
1144	uint			resblks;
1145
1146	trace_xfs_create(dp, name);
1147
1148	if (XFS_FORCED_SHUTDOWN(mp))
1149		return -EIO;
1150
1151	prid = xfs_get_initial_prid(dp);
1152
1153	/*
1154	 * Make sure that we have allocated dquot(s) on disk.
1155	 */
1156	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1157					xfs_kgid_to_gid(current_fsgid()), prid,
1158					XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1159					&udqp, &gdqp, &pdqp);
1160	if (error)
1161		return error;
1162
1163	if (is_dir) {
 
1164		resblks = XFS_MKDIR_SPACE_RES(mp, name->len);
1165		tres = &M_RES(mp)->tr_mkdir;
1166	} else {
1167		resblks = XFS_CREATE_SPACE_RES(mp, name->len);
1168		tres = &M_RES(mp)->tr_create;
1169	}
1170
1171	/*
1172	 * Initially assume that the file does not exist and
1173	 * reserve the resources for that case.  If that is not
1174	 * the case we'll drop the one we have and get a more
1175	 * appropriate transaction later.
1176	 */
1177	error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1178	if (error == -ENOSPC) {
1179		/* flush outstanding delalloc blocks and retry */
1180		xfs_flush_inodes(mp);
1181		error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1182	}
 
 
 
 
 
1183	if (error)
1184		goto out_release_inode;
1185
1186	xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
1187	unlock_dp_on_error = true;
1188
 
 
1189	/*
1190	 * Reserve disk quota and the inode.
1191	 */
1192	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1193						pdqp, resblks, 1, 0);
1194	if (error)
1195		goto out_trans_cancel;
1196
 
 
 
 
 
 
1197	/*
1198	 * A newly created regular or special file just has one directory
1199	 * entry pointing to them, but a directory also the "." entry
1200	 * pointing to itself.
1201	 */
1202	error = xfs_dir_ialloc(&tp, dp, mode, is_dir ? 2 : 1, rdev, prid, &ip);
 
1203	if (error)
1204		goto out_trans_cancel;
1205
1206	/*
1207	 * Now we join the directory inode to the transaction.  We do not do it
1208	 * earlier because xfs_dir_ialloc might commit the previous transaction
1209	 * (and release all the locks).  An error from here on will result in
1210	 * the transaction cancel unlocking dp so don't do it explicitly in the
1211	 * error path.
1212	 */
1213	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
1214	unlock_dp_on_error = false;
1215
1216	error = xfs_dir_createname(tp, dp, name, ip->i_ino,
1217				   resblks ?
1218					resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
1219	if (error) {
1220		ASSERT(error != -ENOSPC);
1221		goto out_trans_cancel;
1222	}
1223	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1224	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1225
1226	if (is_dir) {
1227		error = xfs_dir_init(tp, ip, dp);
1228		if (error)
1229			goto out_trans_cancel;
1230
1231		xfs_bumplink(tp, dp);
 
 
1232	}
1233
1234	/*
1235	 * If this is a synchronous mount, make sure that the
1236	 * create transaction goes to disk before returning to
1237	 * the user.
1238	 */
1239	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1240		xfs_trans_set_sync(tp);
1241
1242	/*
1243	 * Attach the dquot(s) to the inodes and modify them incore.
1244	 * These ids of the inode couldn't have changed since the new
1245	 * inode has been locked ever since it was created.
1246	 */
1247	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1248
 
 
 
 
1249	error = xfs_trans_commit(tp);
1250	if (error)
1251		goto out_release_inode;
1252
1253	xfs_qm_dqrele(udqp);
1254	xfs_qm_dqrele(gdqp);
1255	xfs_qm_dqrele(pdqp);
1256
1257	*ipp = ip;
1258	return 0;
1259
 
 
1260 out_trans_cancel:
1261	xfs_trans_cancel(tp);
1262 out_release_inode:
1263	/*
1264	 * Wait until after the current transaction is aborted to finish the
1265	 * setup of the inode and release the inode.  This prevents recursive
1266	 * transactions and deadlocks from xfs_inactive.
1267	 */
1268	if (ip) {
1269		xfs_finish_inode_setup(ip);
1270		xfs_irele(ip);
1271	}
1272
1273	xfs_qm_dqrele(udqp);
1274	xfs_qm_dqrele(gdqp);
1275	xfs_qm_dqrele(pdqp);
1276
1277	if (unlock_dp_on_error)
1278		xfs_iunlock(dp, XFS_ILOCK_EXCL);
1279	return error;
1280}
1281
1282int
1283xfs_create_tmpfile(
1284	struct xfs_inode	*dp,
 
1285	umode_t			mode,
1286	struct xfs_inode	**ipp)
1287{
1288	struct xfs_mount	*mp = dp->i_mount;
1289	struct xfs_inode	*ip = NULL;
1290	struct xfs_trans	*tp = NULL;
1291	int			error;
1292	prid_t                  prid;
1293	struct xfs_dquot	*udqp = NULL;
1294	struct xfs_dquot	*gdqp = NULL;
1295	struct xfs_dquot	*pdqp = NULL;
1296	struct xfs_trans_res	*tres;
1297	uint			resblks;
1298
1299	if (XFS_FORCED_SHUTDOWN(mp))
1300		return -EIO;
1301
1302	prid = xfs_get_initial_prid(dp);
1303
1304	/*
1305	 * Make sure that we have allocated dquot(s) on disk.
1306	 */
1307	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1308				xfs_kgid_to_gid(current_fsgid()), prid,
1309				XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1310				&udqp, &gdqp, &pdqp);
1311	if (error)
1312		return error;
1313
1314	resblks = XFS_IALLOC_SPACE_RES(mp);
1315	tres = &M_RES(mp)->tr_create_tmpfile;
1316
1317	error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
 
 
 
 
 
1318	if (error)
1319		goto out_release_inode;
1320
1321	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1322						pdqp, resblks, 1, 0);
1323	if (error)
1324		goto out_trans_cancel;
1325
1326	error = xfs_dir_ialloc(&tp, dp, mode, 0, 0, prid, &ip);
 
1327	if (error)
1328		goto out_trans_cancel;
1329
1330	if (mp->m_flags & XFS_MOUNT_WSYNC)
1331		xfs_trans_set_sync(tp);
1332
1333	/*
1334	 * Attach the dquot(s) to the inodes and modify them incore.
1335	 * These ids of the inode couldn't have changed since the new
1336	 * inode has been locked ever since it was created.
1337	 */
1338	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1339
1340	error = xfs_iunlink(tp, ip);
1341	if (error)
1342		goto out_trans_cancel;
1343
1344	error = xfs_trans_commit(tp);
1345	if (error)
1346		goto out_release_inode;
1347
1348	xfs_qm_dqrele(udqp);
1349	xfs_qm_dqrele(gdqp);
1350	xfs_qm_dqrele(pdqp);
1351
1352	*ipp = ip;
1353	return 0;
1354
1355 out_trans_cancel:
1356	xfs_trans_cancel(tp);
1357 out_release_inode:
1358	/*
1359	 * Wait until after the current transaction is aborted to finish the
1360	 * setup of the inode and release the inode.  This prevents recursive
1361	 * transactions and deadlocks from xfs_inactive.
1362	 */
1363	if (ip) {
1364		xfs_finish_inode_setup(ip);
1365		xfs_irele(ip);
1366	}
1367
1368	xfs_qm_dqrele(udqp);
1369	xfs_qm_dqrele(gdqp);
1370	xfs_qm_dqrele(pdqp);
1371
1372	return error;
1373}
1374
1375int
1376xfs_link(
1377	xfs_inode_t		*tdp,
1378	xfs_inode_t		*sip,
1379	struct xfs_name		*target_name)
1380{
1381	xfs_mount_t		*mp = tdp->i_mount;
1382	xfs_trans_t		*tp;
1383	int			error;
 
 
1384	int			resblks;
1385
1386	trace_xfs_link(tdp, target_name);
1387
1388	ASSERT(!S_ISDIR(VFS_I(sip)->i_mode));
1389
1390	if (XFS_FORCED_SHUTDOWN(mp))
1391		return -EIO;
1392
1393	error = xfs_qm_dqattach(sip);
1394	if (error)
1395		goto std_return;
1396
1397	error = xfs_qm_dqattach(tdp);
1398	if (error)
1399		goto std_return;
1400
1401	resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
1402	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, resblks, 0, 0, &tp);
1403	if (error == -ENOSPC) {
1404		resblks = 0;
1405		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, 0, 0, 0, &tp);
1406	}
1407	if (error)
1408		goto std_return;
1409
1410	xfs_lock_two_inodes(sip, XFS_ILOCK_EXCL, tdp, XFS_ILOCK_EXCL);
1411
1412	xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
1413	xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
1414
1415	/*
1416	 * If we are using project inheritance, we only allow hard link
1417	 * creation in our tree when the project IDs are the same; else
1418	 * the tree quota mechanism could be circumvented.
1419	 */
1420	if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
1421		     (xfs_get_projid(tdp) != xfs_get_projid(sip)))) {
1422		error = -EXDEV;
1423		goto error_return;
1424	}
1425
1426	if (!resblks) {
1427		error = xfs_dir_canenter(tp, tdp, target_name);
1428		if (error)
1429			goto error_return;
1430	}
1431
 
 
1432	/*
1433	 * Handle initial link state of O_TMPFILE inode
1434	 */
1435	if (VFS_I(sip)->i_nlink == 0) {
1436		error = xfs_iunlink_remove(tp, sip);
1437		if (error)
1438			goto error_return;
1439	}
1440
1441	error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
1442				   resblks);
1443	if (error)
1444		goto error_return;
1445	xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1446	xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
1447
1448	xfs_bumplink(tp, sip);
 
 
1449
1450	/*
1451	 * If this is a synchronous mount, make sure that the
1452	 * link transaction goes to disk before returning to
1453	 * the user.
1454	 */
1455	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1456		xfs_trans_set_sync(tp);
1457
 
 
 
 
 
 
1458	return xfs_trans_commit(tp);
1459
1460 error_return:
1461	xfs_trans_cancel(tp);
1462 std_return:
1463	return error;
1464}
1465
1466/* Clear the reflink flag and the cowblocks tag if possible. */
1467static void
1468xfs_itruncate_clear_reflink_flags(
1469	struct xfs_inode	*ip)
1470{
1471	struct xfs_ifork	*dfork;
1472	struct xfs_ifork	*cfork;
1473
1474	if (!xfs_is_reflink_inode(ip))
1475		return;
1476	dfork = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
1477	cfork = XFS_IFORK_PTR(ip, XFS_COW_FORK);
1478	if (dfork->if_bytes == 0 && cfork->if_bytes == 0)
1479		ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
1480	if (cfork->if_bytes == 0)
1481		xfs_inode_clear_cowblocks_tag(ip);
1482}
1483
1484/*
1485 * Free up the underlying blocks past new_size.  The new size must be smaller
1486 * than the current size.  This routine can be used both for the attribute and
1487 * data fork, and does not modify the inode size, which is left to the caller.
1488 *
1489 * The transaction passed to this routine must have made a permanent log
1490 * reservation of at least XFS_ITRUNCATE_LOG_RES.  This routine may commit the
1491 * given transaction and start new ones, so make sure everything involved in
1492 * the transaction is tidy before calling here.  Some transaction will be
1493 * returned to the caller to be committed.  The incoming transaction must
1494 * already include the inode, and both inode locks must be held exclusively.
1495 * The inode must also be "held" within the transaction.  On return the inode
1496 * will be "held" within the returned transaction.  This routine does NOT
1497 * require any disk space to be reserved for it within the transaction.
1498 *
1499 * If we get an error, we must return with the inode locked and linked into the
1500 * current transaction. This keeps things simple for the higher level code,
1501 * because it always knows that the inode is locked and held in the transaction
1502 * that returns to it whether errors occur or not.  We don't mark the inode
1503 * dirty on error so that transactions can be easily aborted if possible.
1504 */
1505int
1506xfs_itruncate_extents_flags(
1507	struct xfs_trans	**tpp,
1508	struct xfs_inode	*ip,
1509	int			whichfork,
1510	xfs_fsize_t		new_size,
1511	int			flags)
1512{
1513	struct xfs_mount	*mp = ip->i_mount;
1514	struct xfs_trans	*tp = *tpp;
 
 
1515	xfs_fileoff_t		first_unmap_block;
1516	xfs_fileoff_t		last_block;
1517	xfs_filblks_t		unmap_len;
1518	int			error = 0;
1519	int			done = 0;
1520
1521	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1522	ASSERT(!atomic_read(&VFS_I(ip)->i_count) ||
1523	       xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1524	ASSERT(new_size <= XFS_ISIZE(ip));
1525	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
1526	ASSERT(ip->i_itemp != NULL);
1527	ASSERT(ip->i_itemp->ili_lock_flags == 0);
1528	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1529
1530	trace_xfs_itruncate_extents_start(ip, new_size);
1531
1532	flags |= xfs_bmapi_aflag(whichfork);
1533
1534	/*
1535	 * Since it is possible for space to become allocated beyond
1536	 * the end of the file (in a crash where the space is allocated
1537	 * but the inode size is not yet updated), simply remove any
1538	 * blocks which show up between the new EOF and the maximum
1539	 * possible file size.  If the first block to be removed is
1540	 * beyond the maximum file size (ie it is the same as last_block),
1541	 * then there is nothing to do.
1542	 */
1543	first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
1544	last_block = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
1545	if (first_unmap_block == last_block)
1546		return 0;
1547
1548	ASSERT(first_unmap_block < last_block);
1549	unmap_len = last_block - first_unmap_block + 1;
1550	while (!done) {
1551		ASSERT(tp->t_firstblock == NULLFSBLOCK);
1552		error = xfs_bunmapi(tp, ip, first_unmap_block, unmap_len, flags,
1553				    XFS_ITRUNC_MAX_EXTENTS, &done);
 
 
 
 
1554		if (error)
1555			goto out;
1556
1557		/*
1558		 * Duplicate the transaction that has the permanent
1559		 * reservation and commit the old transaction.
1560		 */
1561		error = xfs_defer_finish(&tp);
1562		if (error)
1563			goto out;
1564
1565		error = xfs_trans_roll_inode(&tp, ip);
1566		if (error)
1567			goto out;
1568	}
1569
1570	if (whichfork == XFS_DATA_FORK) {
1571		/* Remove all pending CoW reservations. */
1572		error = xfs_reflink_cancel_cow_blocks(ip, &tp,
1573				first_unmap_block, last_block, true);
1574		if (error)
1575			goto out;
1576
1577		xfs_itruncate_clear_reflink_flags(ip);
 
 
 
 
 
1578	}
1579
1580	/*
1581	 * Always re-log the inode so that our permanent transaction can keep
1582	 * on rolling it forward in the log.
1583	 */
1584	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1585
1586	trace_xfs_itruncate_extents_end(ip, new_size);
1587
1588out:
1589	*tpp = tp;
1590	return error;
 
 
 
 
 
 
 
 
1591}
1592
1593int
1594xfs_release(
1595	xfs_inode_t	*ip)
1596{
1597	xfs_mount_t	*mp = ip->i_mount;
1598	int		error;
1599
1600	if (!S_ISREG(VFS_I(ip)->i_mode) || (VFS_I(ip)->i_mode == 0))
1601		return 0;
1602
1603	/* If this is a read-only mount, don't do this (would generate I/O) */
1604	if (mp->m_flags & XFS_MOUNT_RDONLY)
1605		return 0;
1606
1607	if (!XFS_FORCED_SHUTDOWN(mp)) {
1608		int truncated;
1609
1610		/*
1611		 * If we previously truncated this file and removed old data
1612		 * in the process, we want to initiate "early" writeout on
1613		 * the last close.  This is an attempt to combat the notorious
1614		 * NULL files problem which is particularly noticeable from a
1615		 * truncate down, buffered (re-)write (delalloc), followed by
1616		 * a crash.  What we are effectively doing here is
1617		 * significantly reducing the time window where we'd otherwise
1618		 * be exposed to that problem.
1619		 */
1620		truncated = xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED);
1621		if (truncated) {
1622			xfs_iflags_clear(ip, XFS_IDIRTY_RELEASE);
1623			if (ip->i_delayed_blks > 0) {
1624				error = filemap_flush(VFS_I(ip)->i_mapping);
1625				if (error)
1626					return error;
1627			}
1628		}
1629	}
1630
1631	if (VFS_I(ip)->i_nlink == 0)
1632		return 0;
1633
1634	if (xfs_can_free_eofblocks(ip, false)) {
1635
1636		/*
1637		 * Check if the inode is being opened, written and closed
1638		 * frequently and we have delayed allocation blocks outstanding
1639		 * (e.g. streaming writes from the NFS server), truncating the
1640		 * blocks past EOF will cause fragmentation to occur.
1641		 *
1642		 * In this case don't do the truncation, but we have to be
1643		 * careful how we detect this case. Blocks beyond EOF show up as
1644		 * i_delayed_blks even when the inode is clean, so we need to
1645		 * truncate them away first before checking for a dirty release.
1646		 * Hence on the first dirty close we will still remove the
1647		 * speculative allocation, but after that we will leave it in
1648		 * place.
1649		 */
1650		if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
1651			return 0;
1652		/*
1653		 * If we can't get the iolock just skip truncating the blocks
1654		 * past EOF because we could deadlock with the mmap_sem
1655		 * otherwise. We'll get another chance to drop them once the
1656		 * last reference to the inode is dropped, so we'll never leak
1657		 * blocks permanently.
1658		 */
1659		if (xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1660			error = xfs_free_eofblocks(ip);
1661			xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1662			if (error)
1663				return error;
1664		}
1665
1666		/* delalloc blocks after truncation means it really is dirty */
1667		if (ip->i_delayed_blks)
1668			xfs_iflags_set(ip, XFS_IDIRTY_RELEASE);
1669	}
1670	return 0;
1671}
1672
1673/*
1674 * xfs_inactive_truncate
1675 *
1676 * Called to perform a truncate when an inode becomes unlinked.
1677 */
1678STATIC int
1679xfs_inactive_truncate(
1680	struct xfs_inode *ip)
1681{
1682	struct xfs_mount	*mp = ip->i_mount;
1683	struct xfs_trans	*tp;
1684	int			error;
1685
1686	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
1687	if (error) {
1688		ASSERT(XFS_FORCED_SHUTDOWN(mp));
1689		return error;
1690	}
 
1691	xfs_ilock(ip, XFS_ILOCK_EXCL);
1692	xfs_trans_ijoin(tp, ip, 0);
1693
1694	/*
1695	 * Log the inode size first to prevent stale data exposure in the event
1696	 * of a system crash before the truncate completes. See the related
1697	 * comment in xfs_vn_setattr_size() for details.
1698	 */
1699	ip->i_d.di_size = 0;
1700	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1701
1702	error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
1703	if (error)
1704		goto error_trans_cancel;
1705
1706	ASSERT(ip->i_d.di_nextents == 0);
1707
1708	error = xfs_trans_commit(tp);
1709	if (error)
1710		goto error_unlock;
1711
1712	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1713	return 0;
1714
1715error_trans_cancel:
1716	xfs_trans_cancel(tp);
1717error_unlock:
1718	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1719	return error;
1720}
1721
1722/*
1723 * xfs_inactive_ifree()
1724 *
1725 * Perform the inode free when an inode is unlinked.
1726 */
1727STATIC int
1728xfs_inactive_ifree(
1729	struct xfs_inode *ip)
1730{
 
 
1731	struct xfs_mount	*mp = ip->i_mount;
1732	struct xfs_trans	*tp;
1733	int			error;
1734
1735	/*
1736	 * We try to use a per-AG reservation for any block needed by the finobt
1737	 * tree, but as the finobt feature predates the per-AG reservation
1738	 * support a degraded file system might not have enough space for the
1739	 * reservation at mount time.  In that case try to dip into the reserved
1740	 * pool and pray.
1741	 *
1742	 * Send a warning if the reservation does happen to fail, as the inode
1743	 * now remains allocated and sits on the unlinked list until the fs is
1744	 * repaired.
1745	 */
1746	if (unlikely(mp->m_finobt_nores)) {
1747		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree,
1748				XFS_IFREE_SPACE_RES(mp), 0, XFS_TRANS_RESERVE,
1749				&tp);
1750	} else {
1751		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree, 0, 0, 0, &tp);
1752	}
1753	if (error) {
1754		if (error == -ENOSPC) {
1755			xfs_warn_ratelimited(mp,
1756			"Failed to remove inode(s) from unlinked list. "
1757			"Please free space, unmount and run xfs_repair.");
1758		} else {
1759			ASSERT(XFS_FORCED_SHUTDOWN(mp));
1760		}
1761		return error;
1762	}
1763
1764	xfs_ilock(ip, XFS_ILOCK_EXCL);
1765	xfs_trans_ijoin(tp, ip, 0);
1766
1767	error = xfs_ifree(tp, ip);
 
1768	if (error) {
1769		/*
1770		 * If we fail to free the inode, shut down.  The cancel
1771		 * might do that, we need to make sure.  Otherwise the
1772		 * inode might be lost for a long time or forever.
1773		 */
1774		if (!XFS_FORCED_SHUTDOWN(mp)) {
1775			xfs_notice(mp, "%s: xfs_ifree returned error %d",
1776				__func__, error);
1777			xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1778		}
1779		xfs_trans_cancel(tp);
1780		xfs_iunlock(ip, XFS_ILOCK_EXCL);
1781		return error;
1782	}
1783
1784	/*
1785	 * Credit the quota account(s). The inode is gone.
1786	 */
1787	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_ICOUNT, -1);
1788
1789	/*
1790	 * Just ignore errors at this point.  There is nothing we can do except
1791	 * to try to keep going. Make sure it's not a silent error.
1792	 */
 
 
 
 
 
 
1793	error = xfs_trans_commit(tp);
1794	if (error)
1795		xfs_notice(mp, "%s: xfs_trans_commit returned error %d",
1796			__func__, error);
1797
1798	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1799	return 0;
1800}
1801
1802/*
1803 * xfs_inactive
1804 *
1805 * This is called when the vnode reference count for the vnode
1806 * goes to zero.  If the file has been unlinked, then it must
1807 * now be truncated.  Also, we clear all of the read-ahead state
1808 * kept for the inode here since the file is now closed.
1809 */
1810void
1811xfs_inactive(
1812	xfs_inode_t	*ip)
1813{
1814	struct xfs_mount	*mp;
1815	int			error;
1816	int			truncate = 0;
1817
1818	/*
1819	 * If the inode is already free, then there can be nothing
1820	 * to clean up here.
1821	 */
1822	if (VFS_I(ip)->i_mode == 0) {
 
1823		ASSERT(ip->i_df.if_broot_bytes == 0);
1824		return;
1825	}
1826
1827	mp = ip->i_mount;
1828	ASSERT(!xfs_iflags_test(ip, XFS_IRECOVERY));
1829
1830	/* If this is a read-only mount, don't do this (would generate I/O) */
1831	if (mp->m_flags & XFS_MOUNT_RDONLY)
1832		return;
1833
1834	/* Try to clean out the cow blocks if there are any. */
1835	if (xfs_inode_has_cow_data(ip))
1836		xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, true);
1837
1838	if (VFS_I(ip)->i_nlink != 0) {
1839		/*
1840		 * force is true because we are evicting an inode from the
1841		 * cache. Post-eof blocks must be freed, lest we end up with
1842		 * broken free space accounting.
1843		 *
1844		 * Note: don't bother with iolock here since lockdep complains
1845		 * about acquiring it in reclaim context. We have the only
1846		 * reference to the inode at this point anyways.
1847		 */
1848		if (xfs_can_free_eofblocks(ip, true))
 
1849			xfs_free_eofblocks(ip);
 
 
1850
1851		return;
1852	}
1853
1854	if (S_ISREG(VFS_I(ip)->i_mode) &&
1855	    (ip->i_d.di_size != 0 || XFS_ISIZE(ip) != 0 ||
1856	     ip->i_d.di_nextents > 0 || ip->i_delayed_blks > 0))
1857		truncate = 1;
1858
1859	error = xfs_qm_dqattach(ip);
1860	if (error)
1861		return;
1862
1863	if (S_ISLNK(VFS_I(ip)->i_mode))
1864		error = xfs_inactive_symlink(ip);
1865	else if (truncate)
1866		error = xfs_inactive_truncate(ip);
1867	if (error)
1868		return;
1869
1870	/*
1871	 * If there are attributes associated with the file then blow them away
1872	 * now.  The code calls a routine that recursively deconstructs the
1873	 * attribute fork. If also blows away the in-core attribute fork.
1874	 */
1875	if (XFS_IFORK_Q(ip)) {
1876		error = xfs_attr_inactive(ip);
1877		if (error)
1878			return;
1879	}
1880
1881	ASSERT(!ip->i_afp);
1882	ASSERT(ip->i_d.di_anextents == 0);
1883	ASSERT(ip->i_d.di_forkoff == 0);
1884
1885	/*
1886	 * Free the inode.
1887	 */
1888	error = xfs_inactive_ifree(ip);
1889	if (error)
1890		return;
1891
1892	/*
1893	 * Release the dquots held by inode, if any.
1894	 */
1895	xfs_qm_dqdetach(ip);
1896}
1897
1898/*
1899 * In-Core Unlinked List Lookups
1900 * =============================
 
 
 
1901 *
1902 * Every inode is supposed to be reachable from some other piece of metadata
1903 * with the exception of the root directory.  Inodes with a connection to a
1904 * file descriptor but not linked from anywhere in the on-disk directory tree
1905 * are collectively known as unlinked inodes, though the filesystem itself
1906 * maintains links to these inodes so that on-disk metadata are consistent.
1907 *
1908 * XFS implements a per-AG on-disk hash table of unlinked inodes.  The AGI
1909 * header contains a number of buckets that point to an inode, and each inode
1910 * record has a pointer to the next inode in the hash chain.  This
1911 * singly-linked list causes scaling problems in the iunlink remove function
1912 * because we must walk that list to find the inode that points to the inode
1913 * being removed from the unlinked hash bucket list.
1914 *
1915 * What if we modelled the unlinked list as a collection of records capturing
1916 * "X.next_unlinked = Y" relations?  If we indexed those records on Y, we'd
1917 * have a fast way to look up unlinked list predecessors, which avoids the
1918 * slow list walk.  That's exactly what we do here (in-core) with a per-AG
1919 * rhashtable.
1920 *
1921 * Because this is a backref cache, we ignore operational failures since the
1922 * iunlink code can fall back to the slow bucket walk.  The only errors that
1923 * should bubble out are for obviously incorrect situations.
1924 *
1925 * All users of the backref cache MUST hold the AGI buffer lock to serialize
1926 * access or have otherwise provided for concurrency control.
1927 */
1928
1929/* Capture a "X.next_unlinked = Y" relationship. */
1930struct xfs_iunlink {
1931	struct rhash_head	iu_rhash_head;
1932	xfs_agino_t		iu_agino;		/* X */
1933	xfs_agino_t		iu_next_unlinked;	/* Y */
1934};
1935
1936/* Unlinked list predecessor lookup hashtable construction */
1937static int
1938xfs_iunlink_obj_cmpfn(
1939	struct rhashtable_compare_arg	*arg,
1940	const void			*obj)
1941{
1942	const xfs_agino_t		*key = arg->key;
1943	const struct xfs_iunlink	*iu = obj;
1944
1945	if (iu->iu_next_unlinked != *key)
1946		return 1;
1947	return 0;
1948}
1949
1950static const struct rhashtable_params xfs_iunlink_hash_params = {
1951	.min_size		= XFS_AGI_UNLINKED_BUCKETS,
1952	.key_len		= sizeof(xfs_agino_t),
1953	.key_offset		= offsetof(struct xfs_iunlink,
1954					   iu_next_unlinked),
1955	.head_offset		= offsetof(struct xfs_iunlink, iu_rhash_head),
1956	.automatic_shrinking	= true,
1957	.obj_cmpfn		= xfs_iunlink_obj_cmpfn,
1958};
1959
1960/*
1961 * Return X, where X.next_unlinked == @agino.  Returns NULLAGINO if no such
1962 * relation is found.
1963 */
1964static xfs_agino_t
1965xfs_iunlink_lookup_backref(
1966	struct xfs_perag	*pag,
1967	xfs_agino_t		agino)
1968{
1969	struct xfs_iunlink	*iu;
1970
1971	iu = rhashtable_lookup_fast(&pag->pagi_unlinked_hash, &agino,
1972			xfs_iunlink_hash_params);
1973	return iu ? iu->iu_agino : NULLAGINO;
1974}
1975
1976/*
1977 * Take ownership of an iunlink cache entry and insert it into the hash table.
1978 * If successful, the entry will be owned by the cache; if not, it is freed.
1979 * Either way, the caller does not own @iu after this call.
1980 */
1981static int
1982xfs_iunlink_insert_backref(
1983	struct xfs_perag	*pag,
1984	struct xfs_iunlink	*iu)
1985{
1986	int			error;
1987
1988	error = rhashtable_insert_fast(&pag->pagi_unlinked_hash,
1989			&iu->iu_rhash_head, xfs_iunlink_hash_params);
1990	/*
1991	 * Fail loudly if there already was an entry because that's a sign of
1992	 * corruption of in-memory data.  Also fail loudly if we see an error
1993	 * code we didn't anticipate from the rhashtable code.  Currently we
1994	 * only anticipate ENOMEM.
1995	 */
1996	if (error) {
1997		WARN(error != -ENOMEM, "iunlink cache insert error %d", error);
1998		kmem_free(iu);
1999	}
2000	/*
2001	 * Absorb any runtime errors that aren't a result of corruption because
2002	 * this is a cache and we can always fall back to bucket list scanning.
2003	 */
2004	if (error != 0 && error != -EEXIST)
2005		error = 0;
2006	return error;
2007}
2008
2009/* Remember that @prev_agino.next_unlinked = @this_agino. */
2010static int
2011xfs_iunlink_add_backref(
2012	struct xfs_perag	*pag,
2013	xfs_agino_t		prev_agino,
2014	xfs_agino_t		this_agino)
2015{
2016	struct xfs_iunlink	*iu;
2017
2018	if (XFS_TEST_ERROR(false, pag->pag_mount, XFS_ERRTAG_IUNLINK_FALLBACK))
2019		return 0;
2020
2021	iu = kmem_zalloc(sizeof(*iu), KM_NOFS);
2022	iu->iu_agino = prev_agino;
2023	iu->iu_next_unlinked = this_agino;
2024
2025	return xfs_iunlink_insert_backref(pag, iu);
2026}
2027
2028/*
2029 * Replace X.next_unlinked = @agino with X.next_unlinked = @next_unlinked.
2030 * If @next_unlinked is NULLAGINO, we drop the backref and exit.  If there
2031 * wasn't any such entry then we don't bother.
2032 */
2033static int
2034xfs_iunlink_change_backref(
2035	struct xfs_perag	*pag,
2036	xfs_agino_t		agino,
2037	xfs_agino_t		next_unlinked)
2038{
2039	struct xfs_iunlink	*iu;
2040	int			error;
 
 
 
 
 
 
 
2041
2042	/* Look up the old entry; if there wasn't one then exit. */
2043	iu = rhashtable_lookup_fast(&pag->pagi_unlinked_hash, &agino,
2044			xfs_iunlink_hash_params);
2045	if (!iu)
2046		return 0;
2047
2048	/*
2049	 * Remove the entry.  This shouldn't ever return an error, but if we
2050	 * couldn't remove the old entry we don't want to add it again to the
2051	 * hash table, and if the entry disappeared on us then someone's
2052	 * violated the locking rules and we need to fail loudly.  Either way
2053	 * we cannot remove the inode because internal state is or would have
2054	 * been corrupt.
2055	 */
2056	error = rhashtable_remove_fast(&pag->pagi_unlinked_hash,
2057			&iu->iu_rhash_head, xfs_iunlink_hash_params);
2058	if (error)
2059		return error;
2060
2061	/* If there is no new next entry just free our item and return. */
2062	if (next_unlinked == NULLAGINO) {
2063		kmem_free(iu);
2064		return 0;
2065	}
2066
2067	/* Update the entry and re-add it to the hash table. */
2068	iu->iu_next_unlinked = next_unlinked;
2069	return xfs_iunlink_insert_backref(pag, iu);
2070}
2071
2072/* Set up the in-core predecessor structures. */
2073int
2074xfs_iunlink_init(
2075	struct xfs_perag	*pag)
2076{
2077	return rhashtable_init(&pag->pagi_unlinked_hash,
2078			&xfs_iunlink_hash_params);
2079}
2080
2081/* Free the in-core predecessor structures. */
2082static void
2083xfs_iunlink_free_item(
2084	void			*ptr,
2085	void			*arg)
2086{
2087	struct xfs_iunlink	*iu = ptr;
2088	bool			*freed_anything = arg;
2089
2090	*freed_anything = true;
2091	kmem_free(iu);
2092}
2093
2094void
2095xfs_iunlink_destroy(
2096	struct xfs_perag	*pag)
2097{
2098	bool			freed_anything = false;
2099
2100	rhashtable_free_and_destroy(&pag->pagi_unlinked_hash,
2101			xfs_iunlink_free_item, &freed_anything);
2102
2103	ASSERT(freed_anything == false || XFS_FORCED_SHUTDOWN(pag->pag_mount));
2104}
2105
2106/*
2107 * Point the AGI unlinked bucket at an inode and log the results.  The caller
2108 * is responsible for validating the old value.
2109 */
2110STATIC int
2111xfs_iunlink_update_bucket(
2112	struct xfs_trans	*tp,
2113	xfs_agnumber_t		agno,
2114	struct xfs_buf		*agibp,
2115	unsigned int		bucket_index,
2116	xfs_agino_t		new_agino)
2117{
2118	struct xfs_agi		*agi = XFS_BUF_TO_AGI(agibp);
2119	xfs_agino_t		old_value;
2120	int			offset;
2121
2122	ASSERT(xfs_verify_agino_or_null(tp->t_mountp, agno, new_agino));
2123
2124	old_value = be32_to_cpu(agi->agi_unlinked[bucket_index]);
2125	trace_xfs_iunlink_update_bucket(tp->t_mountp, agno, bucket_index,
2126			old_value, new_agino);
2127
2128	/*
2129	 * We should never find the head of the list already set to the value
2130	 * passed in because either we're adding or removing ourselves from the
2131	 * head of the list.
2132	 */
2133	if (old_value == new_agino)
2134		return -EFSCORRUPTED;
2135
2136	agi->agi_unlinked[bucket_index] = cpu_to_be32(new_agino);
2137	offset = offsetof(struct xfs_agi, agi_unlinked) +
2138			(sizeof(xfs_agino_t) * bucket_index);
2139	xfs_trans_log_buf(tp, agibp, offset, offset + sizeof(xfs_agino_t) - 1);
2140	return 0;
2141}
2142
2143/* Set an on-disk inode's next_unlinked pointer. */
2144STATIC void
2145xfs_iunlink_update_dinode(
2146	struct xfs_trans	*tp,
2147	xfs_agnumber_t		agno,
2148	xfs_agino_t		agino,
2149	struct xfs_buf		*ibp,
2150	struct xfs_dinode	*dip,
2151	struct xfs_imap		*imap,
2152	xfs_agino_t		next_agino)
2153{
2154	struct xfs_mount	*mp = tp->t_mountp;
2155	int			offset;
2156
2157	ASSERT(xfs_verify_agino_or_null(mp, agno, next_agino));
2158
2159	trace_xfs_iunlink_update_dinode(mp, agno, agino,
2160			be32_to_cpu(dip->di_next_unlinked), next_agino);
2161
2162	dip->di_next_unlinked = cpu_to_be32(next_agino);
2163	offset = imap->im_boffset +
2164			offsetof(struct xfs_dinode, di_next_unlinked);
2165
2166	/* need to recalc the inode CRC if appropriate */
2167	xfs_dinode_calc_crc(mp, dip);
2168	xfs_trans_inode_buf(tp, ibp);
2169	xfs_trans_log_buf(tp, ibp, offset, offset + sizeof(xfs_agino_t) - 1);
2170	xfs_inobp_check(mp, ibp);
2171}
2172
2173/* Set an in-core inode's unlinked pointer and return the old value. */
2174STATIC int
2175xfs_iunlink_update_inode(
2176	struct xfs_trans	*tp,
2177	struct xfs_inode	*ip,
2178	xfs_agnumber_t		agno,
2179	xfs_agino_t		next_agino,
2180	xfs_agino_t		*old_next_agino)
2181{
2182	struct xfs_mount	*mp = tp->t_mountp;
2183	struct xfs_dinode	*dip;
2184	struct xfs_buf		*ibp;
2185	xfs_agino_t		old_value;
2186	int			error;
2187
2188	ASSERT(xfs_verify_agino_or_null(mp, agno, next_agino));
 
 
 
2189
2190	error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp, 0, 0);
2191	if (error)
2192		return error;
2193
2194	/* Make sure the old pointer isn't garbage. */
2195	old_value = be32_to_cpu(dip->di_next_unlinked);
2196	if (!xfs_verify_agino_or_null(mp, agno, old_value)) {
2197		error = -EFSCORRUPTED;
2198		goto out;
2199	}
2200
2201	/*
2202	 * Since we're updating a linked list, we should never find that the
2203	 * current pointer is the same as the new value, unless we're
2204	 * terminating the list.
2205	 */
2206	*old_next_agino = old_value;
2207	if (old_value == next_agino) {
2208		if (next_agino != NULLAGINO)
2209			error = -EFSCORRUPTED;
2210		goto out;
2211	}
2212
2213	/* Ok, update the new pointer. */
2214	xfs_iunlink_update_dinode(tp, agno, XFS_INO_TO_AGINO(mp, ip->i_ino),
2215			ibp, dip, &ip->i_imap, next_agino);
2216	return 0;
2217out:
2218	xfs_trans_brelse(tp, ibp);
2219	return error;
2220}
2221
2222/*
2223 * This is called when the inode's link count has gone to 0 or we are creating
2224 * a tmpfile via O_TMPFILE.  The inode @ip must have nlink == 0.
2225 *
2226 * We place the on-disk inode on a list in the AGI.  It will be pulled from this
2227 * list when the inode is freed.
2228 */
2229STATIC int
2230xfs_iunlink(
2231	struct xfs_trans	*tp,
2232	struct xfs_inode	*ip)
2233{
2234	struct xfs_mount	*mp = tp->t_mountp;
2235	struct xfs_agi		*agi;
2236	struct xfs_buf		*agibp;
2237	xfs_agino_t		next_agino;
2238	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
2239	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
2240	short			bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
2241	int			error;
 
 
 
 
 
 
2242
2243	ASSERT(VFS_I(ip)->i_nlink == 0);
2244	ASSERT(VFS_I(ip)->i_mode != 0);
2245	trace_xfs_iunlink(ip);
2246
2247	/* Get the agi buffer first.  It ensures lock ordering on the list. */
 
 
 
2248	error = xfs_read_agi(mp, tp, agno, &agibp);
2249	if (error)
2250		return error;
 
2251	agi = XFS_BUF_TO_AGI(agibp);
2252
2253	/*
2254	 * Get the index into the agi hash table for the list this inode will
2255	 * go on.  Make sure the pointer isn't garbage and that this inode
2256	 * isn't already on the list.
2257	 */
2258	next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
2259	if (next_agino == agino ||
2260	    !xfs_verify_agino_or_null(mp, agno, next_agino))
2261		return -EFSCORRUPTED;
2262
2263	if (next_agino != NULLAGINO) {
2264		struct xfs_perag	*pag;
2265		xfs_agino_t		old_agino;
2266
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2267		/*
2268		 * There is already another inode in the bucket, so point this
2269		 * inode to the current head of the list.
2270		 */
2271		error = xfs_iunlink_update_inode(tp, ip, agno, next_agino,
2272				&old_agino);
2273		if (error)
2274			return error;
2275		ASSERT(old_agino == NULLAGINO);
2276
 
 
2277		/*
2278		 * agino has been unlinked, add a backref from the next inode
2279		 * back to agino.
2280		 */
2281		pag = xfs_perag_get(mp, agno);
2282		error = xfs_iunlink_add_backref(pag, agino, next_agino);
2283		xfs_perag_put(pag);
2284		if (error)
2285			return error;
2286	}
2287
2288	/* Point the head of the list to point to this inode. */
2289	return xfs_iunlink_update_bucket(tp, agno, agibp, bucket_index, agino);
2290}
2291
2292/* Return the imap, dinode pointer, and buffer for an inode. */
2293STATIC int
2294xfs_iunlink_map_ino(
2295	struct xfs_trans	*tp,
2296	xfs_agnumber_t		agno,
2297	xfs_agino_t		agino,
2298	struct xfs_imap		*imap,
2299	struct xfs_dinode	**dipp,
2300	struct xfs_buf		**bpp)
2301{
2302	struct xfs_mount	*mp = tp->t_mountp;
2303	int			error;
2304
2305	imap->im_blkno = 0;
2306	error = xfs_imap(mp, tp, XFS_AGINO_TO_INO(mp, agno, agino), imap, 0);
2307	if (error) {
2308		xfs_warn(mp, "%s: xfs_imap returned error %d.",
2309				__func__, error);
2310		return error;
2311	}
2312
2313	error = xfs_imap_to_bp(mp, tp, imap, dipp, bpp, 0, 0);
2314	if (error) {
2315		xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
2316				__func__, error);
2317		return error;
2318	}
2319
2320	return 0;
2321}
2322
2323/*
2324 * Walk the unlinked chain from @head_agino until we find the inode that
2325 * points to @target_agino.  Return the inode number, map, dinode pointer,
2326 * and inode cluster buffer of that inode as @agino, @imap, @dipp, and @bpp.
2327 *
2328 * @tp, @pag, @head_agino, and @target_agino are input parameters.
2329 * @agino, @imap, @dipp, and @bpp are all output parameters.
2330 *
2331 * Do not call this function if @target_agino is the head of the list.
2332 */
2333STATIC int
2334xfs_iunlink_map_prev(
2335	struct xfs_trans	*tp,
2336	xfs_agnumber_t		agno,
2337	xfs_agino_t		head_agino,
2338	xfs_agino_t		target_agino,
2339	xfs_agino_t		*agino,
2340	struct xfs_imap		*imap,
2341	struct xfs_dinode	**dipp,
2342	struct xfs_buf		**bpp,
2343	struct xfs_perag	*pag)
2344{
2345	struct xfs_mount	*mp = tp->t_mountp;
2346	xfs_agino_t		next_agino;
2347	int			error;
2348
2349	ASSERT(head_agino != target_agino);
2350	*bpp = NULL;
 
 
 
 
 
2351
2352	/* See if our backref cache can find it faster. */
2353	*agino = xfs_iunlink_lookup_backref(pag, target_agino);
2354	if (*agino != NULLAGINO) {
2355		error = xfs_iunlink_map_ino(tp, agno, *agino, imap, dipp, bpp);
2356		if (error)
2357			return error;
 
 
2358
2359		if (be32_to_cpu((*dipp)->di_next_unlinked) == target_agino)
2360			return 0;
 
 
 
2361
2362		/*
2363		 * If we get here the cache contents were corrupt, so drop the
2364		 * buffer and fall back to walking the bucket list.
2365		 */
2366		xfs_trans_brelse(tp, *bpp);
2367		*bpp = NULL;
2368		WARN_ON_ONCE(1);
2369	}
2370
2371	trace_xfs_iunlink_map_prev_fallback(mp, agno);
2372
2373	/* Otherwise, walk the entire bucket until we find it. */
2374	next_agino = head_agino;
2375	while (next_agino != target_agino) {
2376		xfs_agino_t	unlinked_agino;
2377
2378		if (*bpp)
2379			xfs_trans_brelse(tp, *bpp);
2380
2381		*agino = next_agino;
2382		error = xfs_iunlink_map_ino(tp, agno, next_agino, imap, dipp,
2383				bpp);
2384		if (error)
2385			return error;
2386
2387		unlinked_agino = be32_to_cpu((*dipp)->di_next_unlinked);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2388		/*
2389		 * Make sure this pointer is valid and isn't an obvious
2390		 * infinite loop.
2391		 */
2392		if (!xfs_verify_agino(mp, agno, unlinked_agino) ||
2393		    next_agino == unlinked_agino) {
2394			XFS_CORRUPTION_ERROR(__func__,
2395					XFS_ERRLEVEL_LOW, mp,
2396					*dipp, sizeof(**dipp));
2397			error = -EFSCORRUPTED;
2398			return error;
2399		}
2400		next_agino = unlinked_agino;
2401	}
2402
2403	return 0;
2404}
2405
2406/*
2407 * Pull the on-disk inode from the AGI unlinked list.
2408 */
2409STATIC int
2410xfs_iunlink_remove(
2411	struct xfs_trans	*tp,
2412	struct xfs_inode	*ip)
2413{
2414	struct xfs_mount	*mp = tp->t_mountp;
2415	struct xfs_agi		*agi;
2416	struct xfs_buf		*agibp;
2417	struct xfs_buf		*last_ibp;
2418	struct xfs_dinode	*last_dip = NULL;
2419	struct xfs_perag	*pag = NULL;
2420	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
2421	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
2422	xfs_agino_t		next_agino;
2423	xfs_agino_t		head_agino;
2424	short			bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
2425	int			error;
2426
2427	trace_xfs_iunlink_remove(ip);
2428
2429	/* Get the agi buffer first.  It ensures lock ordering on the list. */
2430	error = xfs_read_agi(mp, tp, agno, &agibp);
2431	if (error)
2432		return error;
2433	agi = XFS_BUF_TO_AGI(agibp);
2434
2435	/*
2436	 * Get the index into the agi hash table for the list this inode will
2437	 * go on.  Make sure the head pointer isn't garbage.
2438	 */
2439	head_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
2440	if (!xfs_verify_agino(mp, agno, head_agino)) {
2441		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
2442				agi, sizeof(*agi));
2443		return -EFSCORRUPTED;
2444	}
2445
2446	/*
2447	 * Set our inode's next_unlinked pointer to NULL and then return
2448	 * the old pointer value so that we can update whatever was previous
2449	 * to us in the list to point to whatever was next in the list.
2450	 */
2451	error = xfs_iunlink_update_inode(tp, ip, agno, NULLAGINO, &next_agino);
2452	if (error)
2453		return error;
2454
2455	/*
2456	 * If there was a backref pointing from the next inode back to this
2457	 * one, remove it because we've removed this inode from the list.
2458	 *
2459	 * Later, if this inode was in the middle of the list we'll update
2460	 * this inode's backref to point from the next inode.
2461	 */
2462	if (next_agino != NULLAGINO) {
2463		pag = xfs_perag_get(mp, agno);
2464		error = xfs_iunlink_change_backref(pag, next_agino,
2465				NULLAGINO);
2466		if (error)
2467			goto out;
2468	}
2469
2470	if (head_agino == agino) {
2471		/* Point the head of the list to the next unlinked inode. */
2472		error = xfs_iunlink_update_bucket(tp, agno, agibp, bucket_index,
2473				next_agino);
2474		if (error)
2475			goto out;
2476	} else {
2477		struct xfs_imap	imap;
2478		xfs_agino_t	prev_agino;
2479
2480		if (!pag)
2481			pag = xfs_perag_get(mp, agno);
2482
2483		/* We need to search the list for the inode being freed. */
2484		error = xfs_iunlink_map_prev(tp, agno, head_agino, agino,
2485				&prev_agino, &imap, &last_dip, &last_ibp,
2486				pag);
2487		if (error)
2488			goto out;
2489
2490		/* Point the previous inode on the list to the next inode. */
2491		xfs_iunlink_update_dinode(tp, agno, prev_agino, last_ibp,
2492				last_dip, &imap, next_agino);
2493
2494		/*
2495		 * Now we deal with the backref for this inode.  If this inode
2496		 * pointed at a real inode, change the backref that pointed to
2497		 * us to point to our old next.  If this inode was the end of
2498		 * the list, delete the backref that pointed to us.  Note that
2499		 * change_backref takes care of deleting the backref if
2500		 * next_agino is NULLAGINO.
2501		 */
2502		error = xfs_iunlink_change_backref(pag, agino, next_agino);
2503		if (error)
2504			goto out;
2505	}
2506
2507out:
2508	if (pag)
2509		xfs_perag_put(pag);
2510	return error;
2511}
2512
2513/*
2514 * A big issue when freeing the inode cluster is that we _cannot_ skip any
2515 * inodes that are in memory - they all must be marked stale and attached to
2516 * the cluster buffer.
2517 */
2518STATIC int
2519xfs_ifree_cluster(
2520	xfs_inode_t		*free_ip,
2521	xfs_trans_t		*tp,
2522	struct xfs_icluster	*xic)
2523{
2524	xfs_mount_t		*mp = free_ip->i_mount;
 
 
2525	int			nbufs;
2526	int			i, j;
2527	int			ioffset;
2528	xfs_daddr_t		blkno;
2529	xfs_buf_t		*bp;
2530	xfs_inode_t		*ip;
2531	xfs_inode_log_item_t	*iip;
2532	struct xfs_log_item	*lip;
2533	struct xfs_perag	*pag;
2534	struct xfs_ino_geometry	*igeo = M_IGEO(mp);
2535	xfs_ino_t		inum;
2536
2537	inum = xic->first_ino;
2538	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, inum));
2539	nbufs = igeo->ialloc_blks / igeo->blocks_per_cluster;
 
 
2540
2541	for (j = 0; j < nbufs; j++, inum += igeo->inodes_per_cluster) {
2542		/*
2543		 * The allocation bitmap tells us which inodes of the chunk were
2544		 * physically allocated. Skip the cluster if an inode falls into
2545		 * a sparse region.
2546		 */
2547		ioffset = inum - xic->first_ino;
2548		if ((xic->alloc & XFS_INOBT_MASK(ioffset)) == 0) {
2549			ASSERT(ioffset % igeo->inodes_per_cluster == 0);
2550			continue;
2551		}
2552
2553		blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
2554					 XFS_INO_TO_AGBNO(mp, inum));
2555
2556		/*
2557		 * We obtain and lock the backing buffer first in the process
2558		 * here, as we have to ensure that any dirty inode that we
2559		 * can't get the flush lock on is attached to the buffer.
2560		 * If we scan the in-memory inodes first, then buffer IO can
2561		 * complete before we get a lock on it, and hence we may fail
2562		 * to mark all the active inodes on the buffer stale.
2563		 */
2564		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
2565					mp->m_bsize * igeo->blocks_per_cluster,
2566					XBF_UNMAPPED);
2567
2568		if (!bp)
2569			return -ENOMEM;
2570
2571		/*
2572		 * This buffer may not have been correctly initialised as we
2573		 * didn't read it from disk. That's not important because we are
2574		 * only using to mark the buffer as stale in the log, and to
2575		 * attach stale cached inodes on it. That means it will never be
2576		 * dispatched for IO. If it is, we want to know about it, and we
2577		 * want it to fail. We can acheive this by adding a write
2578		 * verifier to the buffer.
2579		 */
2580		bp->b_ops = &xfs_inode_buf_ops;
2581
2582		/*
2583		 * Walk the inodes already attached to the buffer and mark them
2584		 * stale. These will all have the flush locks held, so an
2585		 * in-memory inode walk can't lock them. By marking them all
2586		 * stale first, we will not attempt to lock them in the loop
2587		 * below as the XFS_ISTALE flag will be set.
2588		 */
2589		list_for_each_entry(lip, &bp->b_li_list, li_bio_list) {
 
2590			if (lip->li_type == XFS_LI_INODE) {
2591				iip = (xfs_inode_log_item_t *)lip;
2592				ASSERT(iip->ili_logged == 1);
2593				lip->li_cb = xfs_istale_done;
2594				xfs_trans_ail_copy_lsn(mp->m_ail,
2595							&iip->ili_flush_lsn,
2596							&iip->ili_item.li_lsn);
2597				xfs_iflags_set(iip->ili_inode, XFS_ISTALE);
2598			}
 
2599		}
2600
2601
2602		/*
2603		 * For each inode in memory attempt to add it to the inode
2604		 * buffer and set it up for being staled on buffer IO
2605		 * completion.  This is safe as we've locked out tail pushing
2606		 * and flushing by locking the buffer.
2607		 *
2608		 * We have already marked every inode that was part of a
2609		 * transaction stale above, which means there is no point in
2610		 * even trying to lock them.
2611		 */
2612		for (i = 0; i < igeo->inodes_per_cluster; i++) {
2613retry:
2614			rcu_read_lock();
2615			ip = radix_tree_lookup(&pag->pag_ici_root,
2616					XFS_INO_TO_AGINO(mp, (inum + i)));
2617
2618			/* Inode not in memory, nothing to do */
2619			if (!ip) {
2620				rcu_read_unlock();
2621				continue;
2622			}
2623
2624			/*
2625			 * because this is an RCU protected lookup, we could
2626			 * find a recently freed or even reallocated inode
2627			 * during the lookup. We need to check under the
2628			 * i_flags_lock for a valid inode here. Skip it if it
2629			 * is not valid, the wrong inode or stale.
2630			 */
2631			spin_lock(&ip->i_flags_lock);
2632			if (ip->i_ino != inum + i ||
2633			    __xfs_iflags_test(ip, XFS_ISTALE)) {
2634				spin_unlock(&ip->i_flags_lock);
2635				rcu_read_unlock();
2636				continue;
2637			}
2638			spin_unlock(&ip->i_flags_lock);
2639
2640			/*
2641			 * Don't try to lock/unlock the current inode, but we
2642			 * _cannot_ skip the other inodes that we did not find
2643			 * in the list attached to the buffer and are not
2644			 * already marked stale. If we can't lock it, back off
2645			 * and retry.
2646			 */
2647			if (ip != free_ip) {
2648				if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
2649					rcu_read_unlock();
2650					delay(1);
2651					goto retry;
2652				}
2653
2654				/*
2655				 * Check the inode number again in case we're
2656				 * racing with freeing in xfs_reclaim_inode().
2657				 * See the comments in that function for more
2658				 * information as to why the initial check is
2659				 * not sufficient.
2660				 */
2661				if (ip->i_ino != inum + i) {
2662					xfs_iunlock(ip, XFS_ILOCK_EXCL);
2663					rcu_read_unlock();
2664					continue;
2665				}
2666			}
2667			rcu_read_unlock();
2668
2669			xfs_iflock(ip);
2670			xfs_iflags_set(ip, XFS_ISTALE);
2671
2672			/*
2673			 * we don't need to attach clean inodes or those only
2674			 * with unlogged changes (which we throw away, anyway).
2675			 */
2676			iip = ip->i_itemp;
2677			if (!iip || xfs_inode_clean(ip)) {
2678				ASSERT(ip != free_ip);
2679				xfs_ifunlock(ip);
2680				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2681				continue;
2682			}
2683
2684			iip->ili_last_fields = iip->ili_fields;
2685			iip->ili_fields = 0;
2686			iip->ili_fsync_fields = 0;
2687			iip->ili_logged = 1;
2688			xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
2689						&iip->ili_item.li_lsn);
2690
2691			xfs_buf_attach_iodone(bp, xfs_istale_done,
2692						  &iip->ili_item);
2693
2694			if (ip != free_ip)
2695				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2696		}
2697
2698		xfs_trans_stale_inode_buf(tp, bp);
2699		xfs_trans_binval(tp, bp);
2700	}
2701
2702	xfs_perag_put(pag);
2703	return 0;
2704}
2705
2706/*
2707 * Free any local-format buffers sitting around before we reset to
2708 * extents format.
2709 */
2710static inline void
2711xfs_ifree_local_data(
2712	struct xfs_inode	*ip,
2713	int			whichfork)
2714{
2715	struct xfs_ifork	*ifp;
2716
2717	if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL)
2718		return;
2719
2720	ifp = XFS_IFORK_PTR(ip, whichfork);
2721	xfs_idata_realloc(ip, -ifp->if_bytes, whichfork);
2722}
2723
2724/*
2725 * This is called to return an inode to the inode free list.
2726 * The inode should already be truncated to 0 length and have
2727 * no pages associated with it.  This routine also assumes that
2728 * the inode is already a part of the transaction.
2729 *
2730 * The on-disk copy of the inode will have been added to the list
2731 * of unlinked inodes in the AGI. We need to remove the inode from
2732 * that list atomically with respect to freeing it here.
2733 */
2734int
2735xfs_ifree(
2736	struct xfs_trans	*tp,
2737	struct xfs_inode	*ip)
 
2738{
2739	int			error;
2740	struct xfs_icluster	xic = { 0 };
2741
2742	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
2743	ASSERT(VFS_I(ip)->i_nlink == 0);
2744	ASSERT(ip->i_d.di_nextents == 0);
2745	ASSERT(ip->i_d.di_anextents == 0);
2746	ASSERT(ip->i_d.di_size == 0 || !S_ISREG(VFS_I(ip)->i_mode));
2747	ASSERT(ip->i_d.di_nblocks == 0);
2748
2749	/*
2750	 * Pull the on-disk inode from the AGI unlinked list.
2751	 */
2752	error = xfs_iunlink_remove(tp, ip);
2753	if (error)
2754		return error;
2755
2756	error = xfs_difree(tp, ip->i_ino, &xic);
2757	if (error)
2758		return error;
2759
2760	xfs_ifree_local_data(ip, XFS_DATA_FORK);
2761	xfs_ifree_local_data(ip, XFS_ATTR_FORK);
2762
2763	VFS_I(ip)->i_mode = 0;		/* mark incore inode as free */
2764	ip->i_d.di_flags = 0;
2765	ip->i_d.di_flags2 = 0;
2766	ip->i_d.di_dmevmask = 0;
2767	ip->i_d.di_forkoff = 0;		/* mark the attr fork not in use */
2768	ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
2769	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
2770
2771	/* Don't attempt to replay owner changes for a deleted inode */
2772	ip->i_itemp->ili_fields &= ~(XFS_ILOG_AOWNER|XFS_ILOG_DOWNER);
2773
2774	/*
2775	 * Bump the generation count so no one will be confused
2776	 * by reincarnations of this inode.
2777	 */
2778	VFS_I(ip)->i_generation++;
2779	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2780
2781	if (xic.deleted)
2782		error = xfs_ifree_cluster(ip, tp, &xic);
2783
2784	return error;
2785}
2786
2787/*
2788 * This is called to unpin an inode.  The caller must have the inode locked
2789 * in at least shared mode so that the buffer cannot be subsequently pinned
2790 * once someone is waiting for it to be unpinned.
2791 */
2792static void
2793xfs_iunpin(
2794	struct xfs_inode	*ip)
2795{
2796	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
2797
2798	trace_xfs_inode_unpin_nowait(ip, _RET_IP_);
2799
2800	/* Give the log a push to start the unpinning I/O */
2801	xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0, NULL);
2802
2803}
2804
2805static void
2806__xfs_iunpin_wait(
2807	struct xfs_inode	*ip)
2808{
2809	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IPINNED_BIT);
2810	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IPINNED_BIT);
2811
2812	xfs_iunpin(ip);
2813
2814	do {
2815		prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
2816		if (xfs_ipincount(ip))
2817			io_schedule();
2818	} while (xfs_ipincount(ip));
2819	finish_wait(wq, &wait.wq_entry);
2820}
2821
2822void
2823xfs_iunpin_wait(
2824	struct xfs_inode	*ip)
2825{
2826	if (xfs_ipincount(ip))
2827		__xfs_iunpin_wait(ip);
2828}
2829
2830/*
2831 * Removing an inode from the namespace involves removing the directory entry
2832 * and dropping the link count on the inode. Removing the directory entry can
2833 * result in locking an AGF (directory blocks were freed) and removing a link
2834 * count can result in placing the inode on an unlinked list which results in
2835 * locking an AGI.
2836 *
2837 * The big problem here is that we have an ordering constraint on AGF and AGI
2838 * locking - inode allocation locks the AGI, then can allocate a new extent for
2839 * new inodes, locking the AGF after the AGI. Similarly, freeing the inode
2840 * removes the inode from the unlinked list, requiring that we lock the AGI
2841 * first, and then freeing the inode can result in an inode chunk being freed
2842 * and hence freeing disk space requiring that we lock an AGF.
2843 *
2844 * Hence the ordering that is imposed by other parts of the code is AGI before
2845 * AGF. This means we cannot remove the directory entry before we drop the inode
2846 * reference count and put it on the unlinked list as this results in a lock
2847 * order of AGF then AGI, and this can deadlock against inode allocation and
2848 * freeing. Therefore we must drop the link counts before we remove the
2849 * directory entry.
2850 *
2851 * This is still safe from a transactional point of view - it is not until we
2852 * get to xfs_defer_finish() that we have the possibility of multiple
2853 * transactions in this operation. Hence as long as we remove the directory
2854 * entry and drop the link count in the first transaction of the remove
2855 * operation, there are no transactional constraints on the ordering here.
2856 */
2857int
2858xfs_remove(
2859	xfs_inode_t             *dp,
2860	struct xfs_name		*name,
2861	xfs_inode_t		*ip)
2862{
2863	xfs_mount_t		*mp = dp->i_mount;
2864	xfs_trans_t             *tp = NULL;
2865	int			is_dir = S_ISDIR(VFS_I(ip)->i_mode);
2866	int                     error = 0;
 
 
2867	uint			resblks;
2868
2869	trace_xfs_remove(dp, name);
2870
2871	if (XFS_FORCED_SHUTDOWN(mp))
2872		return -EIO;
2873
2874	error = xfs_qm_dqattach(dp);
2875	if (error)
2876		goto std_return;
2877
2878	error = xfs_qm_dqattach(ip);
2879	if (error)
2880		goto std_return;
2881
2882	/*
2883	 * We try to get the real space reservation first,
2884	 * allowing for directory btree deletion(s) implying
2885	 * possible bmap insert(s).  If we can't get the space
2886	 * reservation then we use 0 instead, and avoid the bmap
2887	 * btree insert(s) in the directory code by, if the bmap
2888	 * insert tries to happen, instead trimming the LAST
2889	 * block from the directory.
2890	 */
2891	resblks = XFS_REMOVE_SPACE_RES(mp);
2892	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, resblks, 0, 0, &tp);
2893	if (error == -ENOSPC) {
2894		resblks = 0;
2895		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, 0, 0, 0,
2896				&tp);
2897	}
2898	if (error) {
2899		ASSERT(error != -ENOSPC);
2900		goto std_return;
2901	}
2902
2903	xfs_lock_two_inodes(dp, XFS_ILOCK_EXCL, ip, XFS_ILOCK_EXCL);
2904
2905	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
2906	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
2907
2908	/*
2909	 * If we're removing a directory perform some additional validation.
2910	 */
2911	if (is_dir) {
2912		ASSERT(VFS_I(ip)->i_nlink >= 2);
2913		if (VFS_I(ip)->i_nlink != 2) {
2914			error = -ENOTEMPTY;
2915			goto out_trans_cancel;
2916		}
2917		if (!xfs_dir_isempty(ip)) {
2918			error = -ENOTEMPTY;
2919			goto out_trans_cancel;
2920		}
2921
2922		/* Drop the link from ip's "..".  */
2923		error = xfs_droplink(tp, dp);
2924		if (error)
2925			goto out_trans_cancel;
2926
2927		/* Drop the "." link from ip to self.  */
2928		error = xfs_droplink(tp, ip);
2929		if (error)
2930			goto out_trans_cancel;
2931	} else {
2932		/*
2933		 * When removing a non-directory we need to log the parent
2934		 * inode here.  For a directory this is done implicitly
2935		 * by the xfs_droplink call for the ".." entry.
2936		 */
2937		xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
2938	}
2939	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2940
2941	/* Drop the link from dp to ip. */
2942	error = xfs_droplink(tp, ip);
2943	if (error)
2944		goto out_trans_cancel;
2945
2946	error = xfs_dir_removename(tp, dp, name, ip->i_ino, resblks);
 
 
2947	if (error) {
2948		ASSERT(error != -ENOENT);
2949		goto out_trans_cancel;
2950	}
2951
2952	/*
2953	 * If this is a synchronous mount, make sure that the
2954	 * remove transaction goes to disk before returning to
2955	 * the user.
2956	 */
2957	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2958		xfs_trans_set_sync(tp);
2959
 
 
 
 
2960	error = xfs_trans_commit(tp);
2961	if (error)
2962		goto std_return;
2963
2964	if (is_dir && xfs_inode_is_filestream(ip))
2965		xfs_filestream_deassociate(ip);
2966
2967	return 0;
2968
 
 
2969 out_trans_cancel:
2970	xfs_trans_cancel(tp);
2971 std_return:
2972	return error;
2973}
2974
2975/*
2976 * Enter all inodes for a rename transaction into a sorted array.
2977 */
2978#define __XFS_SORT_INODES	5
2979STATIC void
2980xfs_sort_for_rename(
2981	struct xfs_inode	*dp1,	/* in: old (source) directory inode */
2982	struct xfs_inode	*dp2,	/* in: new (target) directory inode */
2983	struct xfs_inode	*ip1,	/* in: inode of old entry */
2984	struct xfs_inode	*ip2,	/* in: inode of new entry */
2985	struct xfs_inode	*wip,	/* in: whiteout inode */
2986	struct xfs_inode	**i_tab,/* out: sorted array of inodes */
2987	int			*num_inodes)  /* in/out: inodes in array */
2988{
2989	int			i, j;
2990
2991	ASSERT(*num_inodes == __XFS_SORT_INODES);
2992	memset(i_tab, 0, *num_inodes * sizeof(struct xfs_inode *));
2993
2994	/*
2995	 * i_tab contains a list of pointers to inodes.  We initialize
2996	 * the table here & we'll sort it.  We will then use it to
2997	 * order the acquisition of the inode locks.
2998	 *
2999	 * Note that the table may contain duplicates.  e.g., dp1 == dp2.
3000	 */
3001	i = 0;
3002	i_tab[i++] = dp1;
3003	i_tab[i++] = dp2;
3004	i_tab[i++] = ip1;
3005	if (ip2)
3006		i_tab[i++] = ip2;
3007	if (wip)
3008		i_tab[i++] = wip;
3009	*num_inodes = i;
3010
3011	/*
3012	 * Sort the elements via bubble sort.  (Remember, there are at
3013	 * most 5 elements to sort, so this is adequate.)
3014	 */
3015	for (i = 0; i < *num_inodes; i++) {
3016		for (j = 1; j < *num_inodes; j++) {
3017			if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
3018				struct xfs_inode *temp = i_tab[j];
3019				i_tab[j] = i_tab[j-1];
3020				i_tab[j-1] = temp;
3021			}
3022		}
3023	}
3024}
3025
3026static int
3027xfs_finish_rename(
3028	struct xfs_trans	*tp)
 
3029{
 
 
3030	/*
3031	 * If this is a synchronous mount, make sure that the rename transaction
3032	 * goes to disk before returning to the user.
3033	 */
3034	if (tp->t_mountp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
3035		xfs_trans_set_sync(tp);
3036
 
 
 
 
 
 
 
3037	return xfs_trans_commit(tp);
3038}
3039
3040/*
3041 * xfs_cross_rename()
3042 *
3043 * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall
3044 */
3045STATIC int
3046xfs_cross_rename(
3047	struct xfs_trans	*tp,
3048	struct xfs_inode	*dp1,
3049	struct xfs_name		*name1,
3050	struct xfs_inode	*ip1,
3051	struct xfs_inode	*dp2,
3052	struct xfs_name		*name2,
3053	struct xfs_inode	*ip2,
 
 
3054	int			spaceres)
3055{
3056	int		error = 0;
3057	int		ip1_flags = 0;
3058	int		ip2_flags = 0;
3059	int		dp2_flags = 0;
3060
3061	/* Swap inode number for dirent in first parent */
3062	error = xfs_dir_replace(tp, dp1, name1, ip2->i_ino, spaceres);
 
 
3063	if (error)
3064		goto out_trans_abort;
3065
3066	/* Swap inode number for dirent in second parent */
3067	error = xfs_dir_replace(tp, dp2, name2, ip1->i_ino, spaceres);
 
 
3068	if (error)
3069		goto out_trans_abort;
3070
3071	/*
3072	 * If we're renaming one or more directories across different parents,
3073	 * update the respective ".." entries (and link counts) to match the new
3074	 * parents.
3075	 */
3076	if (dp1 != dp2) {
3077		dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
3078
3079		if (S_ISDIR(VFS_I(ip2)->i_mode)) {
3080			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
3081						dp1->i_ino, spaceres);
 
3082			if (error)
3083				goto out_trans_abort;
3084
3085			/* transfer ip2 ".." reference to dp1 */
3086			if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
3087				error = xfs_droplink(tp, dp2);
3088				if (error)
3089					goto out_trans_abort;
3090				xfs_bumplink(tp, dp1);
 
 
3091			}
3092
3093			/*
3094			 * Although ip1 isn't changed here, userspace needs
3095			 * to be warned about the change, so that applications
3096			 * relying on it (like backup ones), will properly
3097			 * notify the change
3098			 */
3099			ip1_flags |= XFS_ICHGTIME_CHG;
3100			ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
3101		}
3102
3103		if (S_ISDIR(VFS_I(ip1)->i_mode)) {
3104			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
3105						dp2->i_ino, spaceres);
 
3106			if (error)
3107				goto out_trans_abort;
3108
3109			/* transfer ip1 ".." reference to dp2 */
3110			if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
3111				error = xfs_droplink(tp, dp1);
3112				if (error)
3113					goto out_trans_abort;
3114				xfs_bumplink(tp, dp2);
 
 
3115			}
3116
3117			/*
3118			 * Although ip2 isn't changed here, userspace needs
3119			 * to be warned about the change, so that applications
3120			 * relying on it (like backup ones), will properly
3121			 * notify the change
3122			 */
3123			ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
3124			ip2_flags |= XFS_ICHGTIME_CHG;
3125		}
3126	}
3127
3128	if (ip1_flags) {
3129		xfs_trans_ichgtime(tp, ip1, ip1_flags);
3130		xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
3131	}
3132	if (ip2_flags) {
3133		xfs_trans_ichgtime(tp, ip2, ip2_flags);
3134		xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
3135	}
3136	if (dp2_flags) {
3137		xfs_trans_ichgtime(tp, dp2, dp2_flags);
3138		xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
3139	}
3140	xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3141	xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
3142	return xfs_finish_rename(tp);
3143
3144out_trans_abort:
 
3145	xfs_trans_cancel(tp);
3146	return error;
3147}
3148
3149/*
3150 * xfs_rename_alloc_whiteout()
3151 *
3152 * Return a referenced, unlinked, unlocked inode that that can be used as a
3153 * whiteout in a rename transaction. We use a tmpfile inode here so that if we
3154 * crash between allocating the inode and linking it into the rename transaction
3155 * recovery will free the inode and we won't leak it.
3156 */
3157static int
3158xfs_rename_alloc_whiteout(
3159	struct xfs_inode	*dp,
3160	struct xfs_inode	**wip)
3161{
3162	struct xfs_inode	*tmpfile;
3163	int			error;
3164
3165	error = xfs_create_tmpfile(dp, S_IFCHR | WHITEOUT_MODE, &tmpfile);
3166	if (error)
3167		return error;
3168
3169	/*
3170	 * Prepare the tmpfile inode as if it were created through the VFS.
3171	 * Complete the inode setup and flag it as linkable.  nlink is already
3172	 * zero, so we can skip the drop_nlink.
 
3173	 */
 
3174	xfs_setup_iops(tmpfile);
3175	xfs_finish_inode_setup(tmpfile);
3176	VFS_I(tmpfile)->i_state |= I_LINKABLE;
3177
3178	*wip = tmpfile;
3179	return 0;
3180}
3181
3182/*
3183 * xfs_rename
3184 */
3185int
3186xfs_rename(
3187	struct xfs_inode	*src_dp,
3188	struct xfs_name		*src_name,
3189	struct xfs_inode	*src_ip,
3190	struct xfs_inode	*target_dp,
3191	struct xfs_name		*target_name,
3192	struct xfs_inode	*target_ip,
3193	unsigned int		flags)
3194{
3195	struct xfs_mount	*mp = src_dp->i_mount;
3196	struct xfs_trans	*tp;
 
 
3197	struct xfs_inode	*wip = NULL;		/* whiteout inode */
3198	struct xfs_inode	*inodes[__XFS_SORT_INODES];
3199	int			num_inodes = __XFS_SORT_INODES;
3200	bool			new_parent = (src_dp != target_dp);
3201	bool			src_is_directory = S_ISDIR(VFS_I(src_ip)->i_mode);
3202	int			spaceres;
3203	int			error;
3204
3205	trace_xfs_rename(src_dp, target_dp, src_name, target_name);
3206
3207	if ((flags & RENAME_EXCHANGE) && !target_ip)
3208		return -EINVAL;
3209
3210	/*
3211	 * If we are doing a whiteout operation, allocate the whiteout inode
3212	 * we will be placing at the target and ensure the type is set
3213	 * appropriately.
3214	 */
3215	if (flags & RENAME_WHITEOUT) {
3216		ASSERT(!(flags & (RENAME_NOREPLACE | RENAME_EXCHANGE)));
3217		error = xfs_rename_alloc_whiteout(target_dp, &wip);
3218		if (error)
3219			return error;
3220
3221		/* setup target dirent info as whiteout */
3222		src_name->type = XFS_DIR3_FT_CHRDEV;
3223	}
3224
3225	xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip, wip,
3226				inodes, &num_inodes);
3227
3228	spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
3229	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, spaceres, 0, 0, &tp);
3230	if (error == -ENOSPC) {
3231		spaceres = 0;
3232		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, 0, 0, 0,
3233				&tp);
3234	}
3235	if (error)
3236		goto out_release_wip;
3237
3238	/*
3239	 * Attach the dquots to the inodes
3240	 */
3241	error = xfs_qm_vop_rename_dqattach(inodes);
3242	if (error)
3243		goto out_trans_cancel;
3244
3245	/*
3246	 * Lock all the participating inodes. Depending upon whether
3247	 * the target_name exists in the target directory, and
3248	 * whether the target directory is the same as the source
3249	 * directory, we can lock from 2 to 4 inodes.
3250	 */
3251	xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
3252
3253	/*
3254	 * Join all the inodes to the transaction. From this point on,
3255	 * we can rely on either trans_commit or trans_cancel to unlock
3256	 * them.
3257	 */
3258	xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
3259	if (new_parent)
3260		xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
3261	xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
3262	if (target_ip)
3263		xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
3264	if (wip)
3265		xfs_trans_ijoin(tp, wip, XFS_ILOCK_EXCL);
3266
3267	/*
3268	 * If we are using project inheritance, we only allow renames
3269	 * into our tree when the project IDs are the same; else the
3270	 * tree quota mechanism would be circumvented.
3271	 */
3272	if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
3273		     (xfs_get_projid(target_dp) != xfs_get_projid(src_ip)))) {
3274		error = -EXDEV;
3275		goto out_trans_cancel;
3276	}
3277
 
 
3278	/* RENAME_EXCHANGE is unique from here on. */
3279	if (flags & RENAME_EXCHANGE)
3280		return xfs_cross_rename(tp, src_dp, src_name, src_ip,
3281					target_dp, target_name, target_ip,
3282					spaceres);
3283
3284	/*
3285	 * Check for expected errors before we dirty the transaction
3286	 * so we can return an error without a transaction abort.
3287	 */
3288	if (target_ip == NULL) {
3289		/*
3290		 * If there's no space reservation, check the entry will
3291		 * fit before actually inserting it.
3292		 */
3293		if (!spaceres) {
3294			error = xfs_dir_canenter(tp, target_dp, target_name);
3295			if (error)
3296				goto out_trans_cancel;
3297		}
3298	} else {
3299		/*
3300		 * If target exists and it's a directory, check that whether
3301		 * it can be destroyed.
3302		 */
3303		if (S_ISDIR(VFS_I(target_ip)->i_mode) &&
3304		    (!xfs_dir_isempty(target_ip) ||
3305		     (VFS_I(target_ip)->i_nlink > 2))) {
3306			error = -EEXIST;
3307			goto out_trans_cancel;
3308		}
3309	}
3310
3311	/*
3312	 * Directory entry creation below may acquire the AGF. Remove
3313	 * the whiteout from the unlinked list first to preserve correct
3314	 * AGI/AGF locking order. This dirties the transaction so failures
3315	 * after this point will abort and log recovery will clean up the
3316	 * mess.
3317	 *
3318	 * For whiteouts, we need to bump the link count on the whiteout
3319	 * inode. After this point, we have a real link, clear the tmpfile
3320	 * state flag from the inode so it doesn't accidentally get misused
3321	 * in future.
3322	 */
3323	if (wip) {
3324		ASSERT(VFS_I(wip)->i_nlink == 0);
3325		error = xfs_iunlink_remove(tp, wip);
3326		if (error)
3327			goto out_trans_cancel;
3328
3329		xfs_bumplink(tp, wip);
3330		xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE);
3331		VFS_I(wip)->i_state &= ~I_LINKABLE;
3332	}
3333
3334	/*
3335	 * Set up the target.
3336	 */
3337	if (target_ip == NULL) {
3338		/*
3339		 * If target does not exist and the rename crosses
3340		 * directories, adjust the target directory link count
3341		 * to account for the ".." reference from the new entry.
3342		 */
3343		error = xfs_dir_createname(tp, target_dp, target_name,
3344					   src_ip->i_ino, spaceres);
 
3345		if (error)
3346			goto out_trans_cancel;
3347
3348		xfs_trans_ichgtime(tp, target_dp,
3349					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3350
3351		if (new_parent && src_is_directory) {
3352			xfs_bumplink(tp, target_dp);
 
 
3353		}
3354	} else { /* target_ip != NULL */
3355		/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3356		 * Link the source inode under the target name.
3357		 * If the source inode is a directory and we are moving
3358		 * it across directories, its ".." entry will be
3359		 * inconsistent until we replace that down below.
3360		 *
3361		 * In case there is already an entry with the same
3362		 * name at the destination directory, remove it first.
3363		 */
3364		error = xfs_dir_replace(tp, target_dp, target_name,
3365					src_ip->i_ino, spaceres);
 
3366		if (error)
3367			goto out_trans_cancel;
3368
3369		xfs_trans_ichgtime(tp, target_dp,
3370					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3371
3372		/*
3373		 * Decrement the link count on the target since the target
3374		 * dir no longer points to it.
3375		 */
3376		error = xfs_droplink(tp, target_ip);
3377		if (error)
3378			goto out_trans_cancel;
3379
3380		if (src_is_directory) {
3381			/*
3382			 * Drop the link from the old "." entry.
3383			 */
3384			error = xfs_droplink(tp, target_ip);
3385			if (error)
3386				goto out_trans_cancel;
3387		}
3388	} /* target_ip != NULL */
3389
3390	/*
3391	 * Remove the source.
3392	 */
3393	if (new_parent && src_is_directory) {
3394		/*
3395		 * Rewrite the ".." entry to point to the new
3396		 * directory.
3397		 */
3398		error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
3399					target_dp->i_ino, spaceres);
 
3400		ASSERT(error != -EEXIST);
3401		if (error)
3402			goto out_trans_cancel;
3403	}
3404
3405	/*
3406	 * We always want to hit the ctime on the source inode.
3407	 *
3408	 * This isn't strictly required by the standards since the source
3409	 * inode isn't really being changed, but old unix file systems did
3410	 * it and some incremental backup programs won't work without it.
3411	 */
3412	xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
3413	xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
3414
3415	/*
3416	 * Adjust the link count on src_dp.  This is necessary when
3417	 * renaming a directory, either within one parent when
3418	 * the target existed, or across two parent directories.
3419	 */
3420	if (src_is_directory && (new_parent || target_ip != NULL)) {
3421
3422		/*
3423		 * Decrement link count on src_directory since the
3424		 * entry that's moved no longer points to it.
3425		 */
3426		error = xfs_droplink(tp, src_dp);
3427		if (error)
3428			goto out_trans_cancel;
3429	}
3430
3431	/*
3432	 * For whiteouts, we only need to update the source dirent with the
3433	 * inode number of the whiteout inode rather than removing it
3434	 * altogether.
3435	 */
3436	if (wip) {
3437		error = xfs_dir_replace(tp, src_dp, src_name, wip->i_ino,
3438					spaceres);
3439	} else
3440		error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
3441					   spaceres);
3442	if (error)
3443		goto out_trans_cancel;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3444
3445	xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3446	xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
3447	if (new_parent)
3448		xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
3449
3450	error = xfs_finish_rename(tp);
3451	if (wip)
3452		xfs_irele(wip);
3453	return error;
3454
 
 
3455out_trans_cancel:
3456	xfs_trans_cancel(tp);
3457out_release_wip:
3458	if (wip)
3459		xfs_irele(wip);
3460	return error;
3461}
3462
3463STATIC int
3464xfs_iflush_cluster(
3465	struct xfs_inode	*ip,
3466	struct xfs_buf		*bp)
3467{
3468	struct xfs_mount	*mp = ip->i_mount;
3469	struct xfs_perag	*pag;
3470	unsigned long		first_index, mask;
 
3471	int			cilist_size;
3472	struct xfs_inode	**cilist;
3473	struct xfs_inode	*cip;
3474	struct xfs_ino_geometry	*igeo = M_IGEO(mp);
3475	int			nr_found;
3476	int			clcount = 0;
 
3477	int			i;
3478
3479	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
3480
3481	cilist_size = igeo->inodes_per_cluster * sizeof(struct xfs_inode *);
 
3482	cilist = kmem_alloc(cilist_size, KM_MAYFAIL|KM_NOFS);
3483	if (!cilist)
3484		goto out_put;
3485
3486	mask = ~(igeo->inodes_per_cluster - 1);
3487	first_index = XFS_INO_TO_AGINO(mp, ip->i_ino) & mask;
3488	rcu_read_lock();
3489	/* really need a gang lookup range call here */
3490	nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void**)cilist,
3491					first_index, igeo->inodes_per_cluster);
3492	if (nr_found == 0)
3493		goto out_free;
3494
3495	for (i = 0; i < nr_found; i++) {
3496		cip = cilist[i];
3497		if (cip == ip)
3498			continue;
3499
3500		/*
3501		 * because this is an RCU protected lookup, we could find a
3502		 * recently freed or even reallocated inode during the lookup.
3503		 * We need to check under the i_flags_lock for a valid inode
3504		 * here. Skip it if it is not valid or the wrong inode.
3505		 */
3506		spin_lock(&cip->i_flags_lock);
3507		if (!cip->i_ino ||
3508		    __xfs_iflags_test(cip, XFS_ISTALE)) {
3509			spin_unlock(&cip->i_flags_lock);
3510			continue;
3511		}
3512
3513		/*
3514		 * Once we fall off the end of the cluster, no point checking
3515		 * any more inodes in the list because they will also all be
3516		 * outside the cluster.
3517		 */
3518		if ((XFS_INO_TO_AGINO(mp, cip->i_ino) & mask) != first_index) {
3519			spin_unlock(&cip->i_flags_lock);
3520			break;
3521		}
3522		spin_unlock(&cip->i_flags_lock);
3523
3524		/*
3525		 * Do an un-protected check to see if the inode is dirty and
3526		 * is a candidate for flushing.  These checks will be repeated
3527		 * later after the appropriate locks are acquired.
3528		 */
3529		if (xfs_inode_clean(cip) && xfs_ipincount(cip) == 0)
3530			continue;
3531
3532		/*
3533		 * Try to get locks.  If any are unavailable or it is pinned,
3534		 * then this inode cannot be flushed and is skipped.
3535		 */
3536
3537		if (!xfs_ilock_nowait(cip, XFS_ILOCK_SHARED))
3538			continue;
3539		if (!xfs_iflock_nowait(cip)) {
3540			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3541			continue;
3542		}
3543		if (xfs_ipincount(cip)) {
3544			xfs_ifunlock(cip);
3545			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3546			continue;
3547		}
3548
3549
3550		/*
3551		 * Check the inode number again, just to be certain we are not
3552		 * racing with freeing in xfs_reclaim_inode(). See the comments
3553		 * in that function for more information as to why the initial
3554		 * check is not sufficient.
3555		 */
3556		if (!cip->i_ino) {
3557			xfs_ifunlock(cip);
3558			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3559			continue;
3560		}
3561
3562		/*
3563		 * arriving here means that this inode can be flushed.  First
3564		 * re-check that it's dirty before flushing.
3565		 */
3566		if (!xfs_inode_clean(cip)) {
3567			int	error;
3568			error = xfs_iflush_int(cip, bp);
3569			if (error) {
3570				xfs_iunlock(cip, XFS_ILOCK_SHARED);
3571				goto cluster_corrupt_out;
3572			}
3573			clcount++;
3574		} else {
3575			xfs_ifunlock(cip);
3576		}
3577		xfs_iunlock(cip, XFS_ILOCK_SHARED);
3578	}
3579
3580	if (clcount) {
3581		XFS_STATS_INC(mp, xs_icluster_flushcnt);
3582		XFS_STATS_ADD(mp, xs_icluster_flushinode, clcount);
3583	}
3584
3585out_free:
3586	rcu_read_unlock();
3587	kmem_free(cilist);
3588out_put:
3589	xfs_perag_put(pag);
3590	return 0;
3591
3592
3593cluster_corrupt_out:
3594	/*
3595	 * Corruption detected in the clustering loop.  Invalidate the
3596	 * inode buffer and shut down the filesystem.
3597	 */
3598	rcu_read_unlock();
3599
3600	/*
3601	 * We'll always have an inode attached to the buffer for completion
3602	 * process by the time we are called from xfs_iflush(). Hence we have
3603	 * always need to do IO completion processing to abort the inodes
3604	 * attached to the buffer.  handle them just like the shutdown case in
3605	 * xfs_buf_submit().
3606	 */
3607	ASSERT(bp->b_iodone);
3608	bp->b_flags |= XBF_ASYNC;
3609	bp->b_flags &= ~XBF_DONE;
3610	xfs_buf_stale(bp);
3611	xfs_buf_ioerror(bp, -EIO);
3612	xfs_buf_ioend(bp);
3613
3614	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3615
3616	/* abort the corrupt inode, as it was not attached to the buffer */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3617	xfs_iflush_abort(cip, false);
3618	kmem_free(cilist);
3619	xfs_perag_put(pag);
3620	return -EFSCORRUPTED;
3621}
3622
3623/*
3624 * Flush dirty inode metadata into the backing buffer.
3625 *
3626 * The caller must have the inode lock and the inode flush lock held.  The
3627 * inode lock will still be held upon return to the caller, and the inode
3628 * flush lock will be released after the inode has reached the disk.
3629 *
3630 * The caller must write out the buffer returned in *bpp and release it.
3631 */
3632int
3633xfs_iflush(
3634	struct xfs_inode	*ip,
3635	struct xfs_buf		**bpp)
3636{
3637	struct xfs_mount	*mp = ip->i_mount;
3638	struct xfs_buf		*bp = NULL;
3639	struct xfs_dinode	*dip;
3640	int			error;
3641
3642	XFS_STATS_INC(mp, xs_iflush_count);
3643
3644	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3645	ASSERT(xfs_isiflocked(ip));
3646	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3647	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3648
3649	*bpp = NULL;
3650
3651	xfs_iunpin_wait(ip);
3652
3653	/*
3654	 * For stale inodes we cannot rely on the backing buffer remaining
3655	 * stale in cache for the remaining life of the stale inode and so
3656	 * xfs_imap_to_bp() below may give us a buffer that no longer contains
3657	 * inodes below. We have to check this after ensuring the inode is
3658	 * unpinned so that it is safe to reclaim the stale inode after the
3659	 * flush call.
3660	 */
3661	if (xfs_iflags_test(ip, XFS_ISTALE)) {
3662		xfs_ifunlock(ip);
3663		return 0;
3664	}
3665
3666	/*
3667	 * This may have been unpinned because the filesystem is shutting
3668	 * down forcibly. If that's the case we must not write this inode
3669	 * to disk, because the log record didn't make it to disk.
3670	 *
3671	 * We also have to remove the log item from the AIL in this case,
3672	 * as we wait for an empty AIL as part of the unmount process.
3673	 */
3674	if (XFS_FORCED_SHUTDOWN(mp)) {
3675		error = -EIO;
3676		goto abort_out;
3677	}
3678
3679	/*
3680	 * Get the buffer containing the on-disk inode. We are doing a try-lock
3681	 * operation here, so we may get  an EAGAIN error. In that case, we
3682	 * simply want to return with the inode still dirty.
3683	 *
3684	 * If we get any other error, we effectively have a corruption situation
3685	 * and we cannot flush the inode, so we treat it the same as failing
3686	 * xfs_iflush_int().
3687	 */
3688	error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, XBF_TRYLOCK,
3689			       0);
3690	if (error == -EAGAIN) {
3691		xfs_ifunlock(ip);
3692		return error;
3693	}
3694	if (error)
3695		goto corrupt_out;
3696
3697	/*
3698	 * First flush out the inode that xfs_iflush was called with.
3699	 */
3700	error = xfs_iflush_int(ip, bp);
3701	if (error)
3702		goto corrupt_out;
3703
3704	/*
3705	 * If the buffer is pinned then push on the log now so we won't
3706	 * get stuck waiting in the write for too long.
3707	 */
3708	if (xfs_buf_ispinned(bp))
3709		xfs_log_force(mp, 0);
3710
3711	/*
3712	 * inode clustering: try to gather other inodes into this write
3713	 *
3714	 * Note: Any error during clustering will result in the filesystem
3715	 * being shut down and completion callbacks run on the cluster buffer.
3716	 * As we have already flushed and attached this inode to the buffer,
3717	 * it has already been aborted and released by xfs_iflush_cluster() and
3718	 * so we have no further error handling to do here.
3719	 */
3720	error = xfs_iflush_cluster(ip, bp);
3721	if (error)
3722		return error;
3723
3724	*bpp = bp;
3725	return 0;
3726
3727corrupt_out:
3728	if (bp)
3729		xfs_buf_relse(bp);
3730	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
 
 
3731abort_out:
3732	/* abort the corrupt inode, as it was not attached to the buffer */
 
 
3733	xfs_iflush_abort(ip, false);
3734	return error;
3735}
3736
3737/*
3738 * If there are inline format data / attr forks attached to this inode,
3739 * make sure they're not corrupt.
3740 */
3741bool
3742xfs_inode_verify_forks(
3743	struct xfs_inode	*ip)
3744{
3745	struct xfs_ifork	*ifp;
3746	xfs_failaddr_t		fa;
3747
3748	fa = xfs_ifork_verify_data(ip, &xfs_default_ifork_ops);
3749	if (fa) {
3750		ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
3751		xfs_inode_verifier_error(ip, -EFSCORRUPTED, "data fork",
3752				ifp->if_u1.if_data, ifp->if_bytes, fa);
3753		return false;
3754	}
3755
3756	fa = xfs_ifork_verify_attr(ip, &xfs_default_ifork_ops);
3757	if (fa) {
3758		ifp = XFS_IFORK_PTR(ip, XFS_ATTR_FORK);
3759		xfs_inode_verifier_error(ip, -EFSCORRUPTED, "attr fork",
3760				ifp ? ifp->if_u1.if_data : NULL,
3761				ifp ? ifp->if_bytes : 0, fa);
3762		return false;
3763	}
3764	return true;
3765}
3766
3767STATIC int
3768xfs_iflush_int(
3769	struct xfs_inode	*ip,
3770	struct xfs_buf		*bp)
3771{
3772	struct xfs_inode_log_item *iip = ip->i_itemp;
3773	struct xfs_dinode	*dip;
3774	struct xfs_mount	*mp = ip->i_mount;
3775
3776	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3777	ASSERT(xfs_isiflocked(ip));
3778	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3779	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3780	ASSERT(iip != NULL && iip->ili_fields != 0);
3781	ASSERT(ip->i_d.di_version > 1);
3782
3783	/* set *dip = inode's place in the buffer */
3784	dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);
3785
3786	if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
3787			       mp, XFS_ERRTAG_IFLUSH_1)) {
3788		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3789			"%s: Bad inode %Lu magic number 0x%x, ptr "PTR_FMT,
3790			__func__, ip->i_ino, be16_to_cpu(dip->di_magic), dip);
3791		goto corrupt_out;
3792	}
3793	if (S_ISREG(VFS_I(ip)->i_mode)) {
3794		if (XFS_TEST_ERROR(
3795		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3796		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
3797		    mp, XFS_ERRTAG_IFLUSH_3)) {
3798			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3799				"%s: Bad regular inode %Lu, ptr "PTR_FMT,
3800				__func__, ip->i_ino, ip);
3801			goto corrupt_out;
3802		}
3803	} else if (S_ISDIR(VFS_I(ip)->i_mode)) {
3804		if (XFS_TEST_ERROR(
3805		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3806		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
3807		    (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
3808		    mp, XFS_ERRTAG_IFLUSH_4)) {
3809			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3810				"%s: Bad directory inode %Lu, ptr "PTR_FMT,
3811				__func__, ip->i_ino, ip);
3812			goto corrupt_out;
3813		}
3814	}
3815	if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
3816				ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5)) {
 
3817		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3818			"%s: detected corrupt incore inode %Lu, "
3819			"total extents = %d, nblocks = %Ld, ptr "PTR_FMT,
3820			__func__, ip->i_ino,
3821			ip->i_d.di_nextents + ip->i_d.di_anextents,
3822			ip->i_d.di_nblocks, ip);
3823		goto corrupt_out;
3824	}
3825	if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
3826				mp, XFS_ERRTAG_IFLUSH_6)) {
3827		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3828			"%s: bad inode %Lu, forkoff 0x%x, ptr "PTR_FMT,
3829			__func__, ip->i_ino, ip->i_d.di_forkoff, ip);
3830		goto corrupt_out;
3831	}
3832
3833	/*
3834	 * Inode item log recovery for v2 inodes are dependent on the
3835	 * di_flushiter count for correct sequencing. We bump the flush
3836	 * iteration count so we can detect flushes which postdate a log record
3837	 * during recovery. This is redundant as we now log every change and
3838	 * hence this can't happen but we need to still do it to ensure
3839	 * backwards compatibility with old kernels that predate logging all
3840	 * inode changes.
3841	 */
3842	if (ip->i_d.di_version < 3)
3843		ip->i_d.di_flushiter++;
3844
3845	/* Check the inline fork data before we write out. */
3846	if (!xfs_inode_verify_forks(ip))
3847		goto corrupt_out;
3848
3849	/*
3850	 * Copy the dirty parts of the inode into the on-disk inode.  We always
3851	 * copy out the core of the inode, because if the inode is dirty at all
3852	 * the core must be.
3853	 */
3854	xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);
3855
3856	/* Wrap, we never let the log put out DI_MAX_FLUSH */
3857	if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
3858		ip->i_d.di_flushiter = 0;
3859
3860	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
3861	if (XFS_IFORK_Q(ip))
3862		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
3863	xfs_inobp_check(mp, bp);
3864
3865	/*
3866	 * We've recorded everything logged in the inode, so we'd like to clear
3867	 * the ili_fields bits so we don't log and flush things unnecessarily.
3868	 * However, we can't stop logging all this information until the data
3869	 * we've copied into the disk buffer is written to disk.  If we did we
3870	 * might overwrite the copy of the inode in the log with all the data
3871	 * after re-logging only part of it, and in the face of a crash we
3872	 * wouldn't have all the data we need to recover.
3873	 *
3874	 * What we do is move the bits to the ili_last_fields field.  When
3875	 * logging the inode, these bits are moved back to the ili_fields field.
3876	 * In the xfs_iflush_done() routine we clear ili_last_fields, since we
3877	 * know that the information those bits represent is permanently on
3878	 * disk.  As long as the flush completes before the inode is logged
3879	 * again, then both ili_fields and ili_last_fields will be cleared.
3880	 *
3881	 * We can play with the ili_fields bits here, because the inode lock
3882	 * must be held exclusively in order to set bits there and the flush
3883	 * lock protects the ili_last_fields bits.  Set ili_logged so the flush
3884	 * done routine can tell whether or not to look in the AIL.  Also, store
3885	 * the current LSN of the inode so that we can tell whether the item has
3886	 * moved in the AIL from xfs_iflush_done().  In order to read the lsn we
3887	 * need the AIL lock, because it is a 64 bit value that cannot be read
3888	 * atomically.
3889	 */
3890	iip->ili_last_fields = iip->ili_fields;
3891	iip->ili_fields = 0;
3892	iip->ili_fsync_fields = 0;
3893	iip->ili_logged = 1;
3894
3895	xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
3896				&iip->ili_item.li_lsn);
3897
3898	/*
3899	 * Attach the function xfs_iflush_done to the inode's
3900	 * buffer.  This will remove the inode from the AIL
3901	 * and unlock the inode's flush lock when the inode is
3902	 * completely written to disk.
3903	 */
3904	xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);
3905
3906	/* generate the checksum. */
3907	xfs_dinode_calc_crc(mp, dip);
3908
3909	ASSERT(!list_empty(&bp->b_li_list));
3910	ASSERT(bp->b_iodone != NULL);
3911	return 0;
3912
3913corrupt_out:
3914	return -EFSCORRUPTED;
3915}
3916
3917/* Release an inode. */
3918void
3919xfs_irele(
3920	struct xfs_inode	*ip)
3921{
3922	trace_xfs_irele(ip, _RET_IP_);
3923	iput(VFS_I(ip));
3924}
v4.10.11
 
   1/*
   2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#include <linux/log2.h>
  19
  20#include "xfs.h"
  21#include "xfs_fs.h"
  22#include "xfs_shared.h"
  23#include "xfs_format.h"
  24#include "xfs_log_format.h"
  25#include "xfs_trans_resv.h"
  26#include "xfs_sb.h"
  27#include "xfs_mount.h"
  28#include "xfs_defer.h"
  29#include "xfs_inode.h"
  30#include "xfs_da_format.h"
  31#include "xfs_da_btree.h"
  32#include "xfs_dir2.h"
  33#include "xfs_attr_sf.h"
  34#include "xfs_attr.h"
  35#include "xfs_trans_space.h"
  36#include "xfs_trans.h"
  37#include "xfs_buf_item.h"
  38#include "xfs_inode_item.h"
  39#include "xfs_ialloc.h"
  40#include "xfs_bmap.h"
  41#include "xfs_bmap_util.h"
 
  42#include "xfs_error.h"
  43#include "xfs_quota.h"
  44#include "xfs_filestream.h"
  45#include "xfs_cksum.h"
  46#include "xfs_trace.h"
  47#include "xfs_icache.h"
  48#include "xfs_symlink.h"
  49#include "xfs_trans_priv.h"
  50#include "xfs_log.h"
  51#include "xfs_bmap_btree.h"
  52#include "xfs_reflink.h"
  53
  54kmem_zone_t *xfs_inode_zone;
  55
  56/*
  57 * Used in xfs_itruncate_extents().  This is the maximum number of extents
  58 * freed from a file in a single transaction.
  59 */
  60#define	XFS_ITRUNC_MAX_EXTENTS	2
  61
  62STATIC int xfs_iflush_int(struct xfs_inode *, struct xfs_buf *);
  63STATIC int xfs_iunlink(struct xfs_trans *, struct xfs_inode *);
  64STATIC int xfs_iunlink_remove(struct xfs_trans *, struct xfs_inode *);
  65
  66/*
  67 * helper function to extract extent size hint from inode
  68 */
  69xfs_extlen_t
  70xfs_get_extsz_hint(
  71	struct xfs_inode	*ip)
  72{
  73	if ((ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE) && ip->i_d.di_extsize)
  74		return ip->i_d.di_extsize;
  75	if (XFS_IS_REALTIME_INODE(ip))
  76		return ip->i_mount->m_sb.sb_rextsize;
  77	return 0;
  78}
  79
  80/*
  81 * Helper function to extract CoW extent size hint from inode.
  82 * Between the extent size hint and the CoW extent size hint, we
  83 * return the greater of the two.  If the value is zero (automatic),
  84 * use the default size.
  85 */
  86xfs_extlen_t
  87xfs_get_cowextsz_hint(
  88	struct xfs_inode	*ip)
  89{
  90	xfs_extlen_t		a, b;
  91
  92	a = 0;
  93	if (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
  94		a = ip->i_d.di_cowextsize;
  95	b = xfs_get_extsz_hint(ip);
  96
  97	a = max(a, b);
  98	if (a == 0)
  99		return XFS_DEFAULT_COWEXTSZ_HINT;
 100	return a;
 101}
 102
 103/*
 104 * These two are wrapper routines around the xfs_ilock() routine used to
 105 * centralize some grungy code.  They are used in places that wish to lock the
 106 * inode solely for reading the extents.  The reason these places can't just
 107 * call xfs_ilock(ip, XFS_ILOCK_SHARED) is that the inode lock also guards to
 108 * bringing in of the extents from disk for a file in b-tree format.  If the
 109 * inode is in b-tree format, then we need to lock the inode exclusively until
 110 * the extents are read in.  Locking it exclusively all the time would limit
 111 * our parallelism unnecessarily, though.  What we do instead is check to see
 112 * if the extents have been read in yet, and only lock the inode exclusively
 113 * if they have not.
 114 *
 115 * The functions return a value which should be given to the corresponding
 116 * xfs_iunlock() call.
 117 */
 118uint
 119xfs_ilock_data_map_shared(
 120	struct xfs_inode	*ip)
 121{
 122	uint			lock_mode = XFS_ILOCK_SHARED;
 123
 124	if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
 125	    (ip->i_df.if_flags & XFS_IFEXTENTS) == 0)
 126		lock_mode = XFS_ILOCK_EXCL;
 127	xfs_ilock(ip, lock_mode);
 128	return lock_mode;
 129}
 130
 131uint
 132xfs_ilock_attr_map_shared(
 133	struct xfs_inode	*ip)
 134{
 135	uint			lock_mode = XFS_ILOCK_SHARED;
 136
 137	if (ip->i_d.di_aformat == XFS_DINODE_FMT_BTREE &&
 138	    (ip->i_afp->if_flags & XFS_IFEXTENTS) == 0)
 139		lock_mode = XFS_ILOCK_EXCL;
 140	xfs_ilock(ip, lock_mode);
 141	return lock_mode;
 142}
 143
 144/*
 145 * In addition to i_rwsem in the VFS inode, the xfs inode contains 2
 146 * multi-reader locks: i_mmap_lock and the i_lock.  This routine allows
 147 * various combinations of the locks to be obtained.
 148 *
 149 * The 3 locks should always be ordered so that the IO lock is obtained first,
 150 * the mmap lock second and the ilock last in order to prevent deadlock.
 151 *
 152 * Basic locking order:
 153 *
 154 * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock
 155 *
 156 * mmap_sem locking order:
 157 *
 158 * i_rwsem -> page lock -> mmap_sem
 159 * mmap_sem -> i_mmap_lock -> page_lock
 160 *
 161 * The difference in mmap_sem locking order mean that we cannot hold the
 162 * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can
 163 * fault in pages during copy in/out (for buffered IO) or require the mmap_sem
 164 * in get_user_pages() to map the user pages into the kernel address space for
 165 * direct IO. Similarly the i_rwsem cannot be taken inside a page fault because
 166 * page faults already hold the mmap_sem.
 167 *
 168 * Hence to serialise fully against both syscall and mmap based IO, we need to
 169 * take both the i_rwsem and the i_mmap_lock. These locks should *only* be both
 170 * taken in places where we need to invalidate the page cache in a race
 171 * free manner (e.g. truncate, hole punch and other extent manipulation
 172 * functions).
 173 */
 174void
 175xfs_ilock(
 176	xfs_inode_t		*ip,
 177	uint			lock_flags)
 178{
 179	trace_xfs_ilock(ip, lock_flags, _RET_IP_);
 180
 181	/*
 182	 * You can't set both SHARED and EXCL for the same lock,
 183	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 184	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 185	 */
 186	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 187	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 188	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 189	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 190	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 191	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 192	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 193
 194	if (lock_flags & XFS_IOLOCK_EXCL) {
 195		down_write_nested(&VFS_I(ip)->i_rwsem,
 196				  XFS_IOLOCK_DEP(lock_flags));
 197	} else if (lock_flags & XFS_IOLOCK_SHARED) {
 198		down_read_nested(&VFS_I(ip)->i_rwsem,
 199				 XFS_IOLOCK_DEP(lock_flags));
 200	}
 201
 202	if (lock_flags & XFS_MMAPLOCK_EXCL)
 203		mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
 204	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 205		mraccess_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
 206
 207	if (lock_flags & XFS_ILOCK_EXCL)
 208		mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
 209	else if (lock_flags & XFS_ILOCK_SHARED)
 210		mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
 211}
 212
 213/*
 214 * This is just like xfs_ilock(), except that the caller
 215 * is guaranteed not to sleep.  It returns 1 if it gets
 216 * the requested locks and 0 otherwise.  If the IO lock is
 217 * obtained but the inode lock cannot be, then the IO lock
 218 * is dropped before returning.
 219 *
 220 * ip -- the inode being locked
 221 * lock_flags -- this parameter indicates the inode's locks to be
 222 *       to be locked.  See the comment for xfs_ilock() for a list
 223 *	 of valid values.
 224 */
 225int
 226xfs_ilock_nowait(
 227	xfs_inode_t		*ip,
 228	uint			lock_flags)
 229{
 230	trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
 231
 232	/*
 233	 * You can't set both SHARED and EXCL for the same lock,
 234	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 235	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 236	 */
 237	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 238	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 239	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 240	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 241	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 242	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 243	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 244
 245	if (lock_flags & XFS_IOLOCK_EXCL) {
 246		if (!down_write_trylock(&VFS_I(ip)->i_rwsem))
 247			goto out;
 248	} else if (lock_flags & XFS_IOLOCK_SHARED) {
 249		if (!down_read_trylock(&VFS_I(ip)->i_rwsem))
 250			goto out;
 251	}
 252
 253	if (lock_flags & XFS_MMAPLOCK_EXCL) {
 254		if (!mrtryupdate(&ip->i_mmaplock))
 255			goto out_undo_iolock;
 256	} else if (lock_flags & XFS_MMAPLOCK_SHARED) {
 257		if (!mrtryaccess(&ip->i_mmaplock))
 258			goto out_undo_iolock;
 259	}
 260
 261	if (lock_flags & XFS_ILOCK_EXCL) {
 262		if (!mrtryupdate(&ip->i_lock))
 263			goto out_undo_mmaplock;
 264	} else if (lock_flags & XFS_ILOCK_SHARED) {
 265		if (!mrtryaccess(&ip->i_lock))
 266			goto out_undo_mmaplock;
 267	}
 268	return 1;
 269
 270out_undo_mmaplock:
 271	if (lock_flags & XFS_MMAPLOCK_EXCL)
 272		mrunlock_excl(&ip->i_mmaplock);
 273	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 274		mrunlock_shared(&ip->i_mmaplock);
 275out_undo_iolock:
 276	if (lock_flags & XFS_IOLOCK_EXCL)
 277		up_write(&VFS_I(ip)->i_rwsem);
 278	else if (lock_flags & XFS_IOLOCK_SHARED)
 279		up_read(&VFS_I(ip)->i_rwsem);
 280out:
 281	return 0;
 282}
 283
 284/*
 285 * xfs_iunlock() is used to drop the inode locks acquired with
 286 * xfs_ilock() and xfs_ilock_nowait().  The caller must pass
 287 * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
 288 * that we know which locks to drop.
 289 *
 290 * ip -- the inode being unlocked
 291 * lock_flags -- this parameter indicates the inode's locks to be
 292 *       to be unlocked.  See the comment for xfs_ilock() for a list
 293 *	 of valid values for this parameter.
 294 *
 295 */
 296void
 297xfs_iunlock(
 298	xfs_inode_t		*ip,
 299	uint			lock_flags)
 300{
 301	/*
 302	 * You can't set both SHARED and EXCL for the same lock,
 303	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 304	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 305	 */
 306	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 307	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 308	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 309	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 310	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 311	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 312	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 313	ASSERT(lock_flags != 0);
 314
 315	if (lock_flags & XFS_IOLOCK_EXCL)
 316		up_write(&VFS_I(ip)->i_rwsem);
 317	else if (lock_flags & XFS_IOLOCK_SHARED)
 318		up_read(&VFS_I(ip)->i_rwsem);
 319
 320	if (lock_flags & XFS_MMAPLOCK_EXCL)
 321		mrunlock_excl(&ip->i_mmaplock);
 322	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 323		mrunlock_shared(&ip->i_mmaplock);
 324
 325	if (lock_flags & XFS_ILOCK_EXCL)
 326		mrunlock_excl(&ip->i_lock);
 327	else if (lock_flags & XFS_ILOCK_SHARED)
 328		mrunlock_shared(&ip->i_lock);
 329
 330	trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
 331}
 332
 333/*
 334 * give up write locks.  the i/o lock cannot be held nested
 335 * if it is being demoted.
 336 */
 337void
 338xfs_ilock_demote(
 339	xfs_inode_t		*ip,
 340	uint			lock_flags)
 341{
 342	ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL));
 343	ASSERT((lock_flags &
 344		~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
 345
 346	if (lock_flags & XFS_ILOCK_EXCL)
 347		mrdemote(&ip->i_lock);
 348	if (lock_flags & XFS_MMAPLOCK_EXCL)
 349		mrdemote(&ip->i_mmaplock);
 350	if (lock_flags & XFS_IOLOCK_EXCL)
 351		downgrade_write(&VFS_I(ip)->i_rwsem);
 352
 353	trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
 354}
 355
 356#if defined(DEBUG) || defined(XFS_WARN)
 357int
 358xfs_isilocked(
 359	xfs_inode_t		*ip,
 360	uint			lock_flags)
 361{
 362	if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
 363		if (!(lock_flags & XFS_ILOCK_SHARED))
 364			return !!ip->i_lock.mr_writer;
 365		return rwsem_is_locked(&ip->i_lock.mr_lock);
 366	}
 367
 368	if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) {
 369		if (!(lock_flags & XFS_MMAPLOCK_SHARED))
 370			return !!ip->i_mmaplock.mr_writer;
 371		return rwsem_is_locked(&ip->i_mmaplock.mr_lock);
 372	}
 373
 374	if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
 375		if (!(lock_flags & XFS_IOLOCK_SHARED))
 376			return !debug_locks ||
 377				lockdep_is_held_type(&VFS_I(ip)->i_rwsem, 0);
 378		return rwsem_is_locked(&VFS_I(ip)->i_rwsem);
 379	}
 380
 381	ASSERT(0);
 382	return 0;
 383}
 384#endif
 385
 386#ifdef DEBUG
 387int xfs_locked_n;
 388int xfs_small_retries;
 389int xfs_middle_retries;
 390int xfs_lots_retries;
 391int xfs_lock_delays;
 392#endif
 393
 394/*
 395 * xfs_lockdep_subclass_ok() is only used in an ASSERT, so is only called when
 396 * DEBUG or XFS_WARN is set. And MAX_LOCKDEP_SUBCLASSES is then only defined
 397 * when CONFIG_LOCKDEP is set. Hence the complex define below to avoid build
 398 * errors and warnings.
 399 */
 400#if (defined(DEBUG) || defined(XFS_WARN)) && defined(CONFIG_LOCKDEP)
 401static bool
 402xfs_lockdep_subclass_ok(
 403	int subclass)
 404{
 405	return subclass < MAX_LOCKDEP_SUBCLASSES;
 406}
 407#else
 408#define xfs_lockdep_subclass_ok(subclass)	(true)
 409#endif
 410
 411/*
 412 * Bump the subclass so xfs_lock_inodes() acquires each lock with a different
 413 * value. This can be called for any type of inode lock combination, including
 414 * parent locking. Care must be taken to ensure we don't overrun the subclass
 415 * storage fields in the class mask we build.
 416 */
 417static inline int
 418xfs_lock_inumorder(int lock_mode, int subclass)
 419{
 420	int	class = 0;
 421
 422	ASSERT(!(lock_mode & (XFS_ILOCK_PARENT | XFS_ILOCK_RTBITMAP |
 423			      XFS_ILOCK_RTSUM)));
 424	ASSERT(xfs_lockdep_subclass_ok(subclass));
 425
 426	if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) {
 427		ASSERT(subclass <= XFS_IOLOCK_MAX_SUBCLASS);
 428		class += subclass << XFS_IOLOCK_SHIFT;
 429	}
 430
 431	if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) {
 432		ASSERT(subclass <= XFS_MMAPLOCK_MAX_SUBCLASS);
 433		class += subclass << XFS_MMAPLOCK_SHIFT;
 434	}
 435
 436	if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) {
 437		ASSERT(subclass <= XFS_ILOCK_MAX_SUBCLASS);
 438		class += subclass << XFS_ILOCK_SHIFT;
 439	}
 440
 441	return (lock_mode & ~XFS_LOCK_SUBCLASS_MASK) | class;
 442}
 443
 444/*
 445 * The following routine will lock n inodes in exclusive mode.  We assume the
 446 * caller calls us with the inodes in i_ino order.
 447 *
 448 * We need to detect deadlock where an inode that we lock is in the AIL and we
 449 * start waiting for another inode that is locked by a thread in a long running
 450 * transaction (such as truncate). This can result in deadlock since the long
 451 * running trans might need to wait for the inode we just locked in order to
 452 * push the tail and free space in the log.
 453 *
 454 * xfs_lock_inodes() can only be used to lock one type of lock at a time -
 455 * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
 456 * lock more than one at a time, lockdep will report false positives saying we
 457 * have violated locking orders.
 458 */
 459static void
 460xfs_lock_inodes(
 461	xfs_inode_t	**ips,
 462	int		inodes,
 463	uint		lock_mode)
 464{
 465	int		attempts = 0, i, j, try_lock;
 466	xfs_log_item_t	*lp;
 467
 468	/*
 469	 * Currently supports between 2 and 5 inodes with exclusive locking.  We
 470	 * support an arbitrary depth of locking here, but absolute limits on
 471	 * inodes depend on the the type of locking and the limits placed by
 472	 * lockdep annotations in xfs_lock_inumorder.  These are all checked by
 473	 * the asserts.
 474	 */
 475	ASSERT(ips && inodes >= 2 && inodes <= 5);
 476	ASSERT(lock_mode & (XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL |
 477			    XFS_ILOCK_EXCL));
 478	ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED | XFS_MMAPLOCK_SHARED |
 479			      XFS_ILOCK_SHARED)));
 480	ASSERT(!(lock_mode & XFS_MMAPLOCK_EXCL) ||
 481		inodes <= XFS_MMAPLOCK_MAX_SUBCLASS + 1);
 482	ASSERT(!(lock_mode & XFS_ILOCK_EXCL) ||
 483		inodes <= XFS_ILOCK_MAX_SUBCLASS + 1);
 484
 485	if (lock_mode & XFS_IOLOCK_EXCL) {
 486		ASSERT(!(lock_mode & (XFS_MMAPLOCK_EXCL | XFS_ILOCK_EXCL)));
 487	} else if (lock_mode & XFS_MMAPLOCK_EXCL)
 488		ASSERT(!(lock_mode & XFS_ILOCK_EXCL));
 489
 490	try_lock = 0;
 491	i = 0;
 492again:
 493	for (; i < inodes; i++) {
 494		ASSERT(ips[i]);
 495
 496		if (i && (ips[i] == ips[i - 1]))	/* Already locked */
 497			continue;
 498
 499		/*
 500		 * If try_lock is not set yet, make sure all locked inodes are
 501		 * not in the AIL.  If any are, set try_lock to be used later.
 502		 */
 503		if (!try_lock) {
 504			for (j = (i - 1); j >= 0 && !try_lock; j--) {
 505				lp = (xfs_log_item_t *)ips[j]->i_itemp;
 506				if (lp && (lp->li_flags & XFS_LI_IN_AIL))
 507					try_lock++;
 508			}
 509		}
 510
 511		/*
 512		 * If any of the previous locks we have locked is in the AIL,
 513		 * we must TRY to get the second and subsequent locks. If
 514		 * we can't get any, we must release all we have
 515		 * and try again.
 516		 */
 517		if (!try_lock) {
 518			xfs_ilock(ips[i], xfs_lock_inumorder(lock_mode, i));
 519			continue;
 520		}
 521
 522		/* try_lock means we have an inode locked that is in the AIL. */
 523		ASSERT(i != 0);
 524		if (xfs_ilock_nowait(ips[i], xfs_lock_inumorder(lock_mode, i)))
 525			continue;
 526
 527		/*
 528		 * Unlock all previous guys and try again.  xfs_iunlock will try
 529		 * to push the tail if the inode is in the AIL.
 530		 */
 531		attempts++;
 532		for (j = i - 1; j >= 0; j--) {
 533			/*
 534			 * Check to see if we've already unlocked this one.  Not
 535			 * the first one going back, and the inode ptr is the
 536			 * same.
 537			 */
 538			if (j != (i - 1) && ips[j] == ips[j + 1])
 539				continue;
 540
 541			xfs_iunlock(ips[j], lock_mode);
 542		}
 543
 544		if ((attempts % 5) == 0) {
 545			delay(1); /* Don't just spin the CPU */
 546#ifdef DEBUG
 547			xfs_lock_delays++;
 548#endif
 549		}
 550		i = 0;
 551		try_lock = 0;
 552		goto again;
 553	}
 554
 555#ifdef DEBUG
 556	if (attempts) {
 557		if (attempts < 5) xfs_small_retries++;
 558		else if (attempts < 100) xfs_middle_retries++;
 559		else xfs_lots_retries++;
 560	} else {
 561		xfs_locked_n++;
 562	}
 563#endif
 564}
 565
 566/*
 567 * xfs_lock_two_inodes() can only be used to lock one type of lock at a time -
 568 * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
 569 * lock more than one at a time, lockdep will report false positives saying we
 570 * have violated locking orders.
 
 
 571 */
 572void
 573xfs_lock_two_inodes(
 574	xfs_inode_t		*ip0,
 575	xfs_inode_t		*ip1,
 576	uint			lock_mode)
 
 577{
 578	xfs_inode_t		*temp;
 
 579	int			attempts = 0;
 580	xfs_log_item_t		*lp;
 581
 582	ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
 583	if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL))
 584		ASSERT(!(lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
 
 
 
 
 
 
 
 
 
 585
 586	ASSERT(ip0->i_ino != ip1->i_ino);
 587
 588	if (ip0->i_ino > ip1->i_ino) {
 589		temp = ip0;
 590		ip0 = ip1;
 591		ip1 = temp;
 
 
 
 592	}
 593
 594 again:
 595	xfs_ilock(ip0, xfs_lock_inumorder(lock_mode, 0));
 596
 597	/*
 598	 * If the first lock we have locked is in the AIL, we must TRY to get
 599	 * the second lock. If we can't get it, we must release the first one
 600	 * and try again.
 601	 */
 602	lp = (xfs_log_item_t *)ip0->i_itemp;
 603	if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
 604		if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(lock_mode, 1))) {
 605			xfs_iunlock(ip0, lock_mode);
 606			if ((++attempts % 5) == 0)
 607				delay(1); /* Don't just spin the CPU */
 608			goto again;
 609		}
 610	} else {
 611		xfs_ilock(ip1, xfs_lock_inumorder(lock_mode, 1));
 612	}
 613}
 614
 615
 616void
 617__xfs_iflock(
 618	struct xfs_inode	*ip)
 619{
 620	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IFLOCK_BIT);
 621	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IFLOCK_BIT);
 622
 623	do {
 624		prepare_to_wait_exclusive(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
 625		if (xfs_isiflocked(ip))
 626			io_schedule();
 627	} while (!xfs_iflock_nowait(ip));
 628
 629	finish_wait(wq, &wait.wait);
 630}
 631
 632STATIC uint
 633_xfs_dic2xflags(
 634	__uint16_t		di_flags,
 635	uint64_t		di_flags2,
 636	bool			has_attr)
 637{
 638	uint			flags = 0;
 639
 640	if (di_flags & XFS_DIFLAG_ANY) {
 641		if (di_flags & XFS_DIFLAG_REALTIME)
 642			flags |= FS_XFLAG_REALTIME;
 643		if (di_flags & XFS_DIFLAG_PREALLOC)
 644			flags |= FS_XFLAG_PREALLOC;
 645		if (di_flags & XFS_DIFLAG_IMMUTABLE)
 646			flags |= FS_XFLAG_IMMUTABLE;
 647		if (di_flags & XFS_DIFLAG_APPEND)
 648			flags |= FS_XFLAG_APPEND;
 649		if (di_flags & XFS_DIFLAG_SYNC)
 650			flags |= FS_XFLAG_SYNC;
 651		if (di_flags & XFS_DIFLAG_NOATIME)
 652			flags |= FS_XFLAG_NOATIME;
 653		if (di_flags & XFS_DIFLAG_NODUMP)
 654			flags |= FS_XFLAG_NODUMP;
 655		if (di_flags & XFS_DIFLAG_RTINHERIT)
 656			flags |= FS_XFLAG_RTINHERIT;
 657		if (di_flags & XFS_DIFLAG_PROJINHERIT)
 658			flags |= FS_XFLAG_PROJINHERIT;
 659		if (di_flags & XFS_DIFLAG_NOSYMLINKS)
 660			flags |= FS_XFLAG_NOSYMLINKS;
 661		if (di_flags & XFS_DIFLAG_EXTSIZE)
 662			flags |= FS_XFLAG_EXTSIZE;
 663		if (di_flags & XFS_DIFLAG_EXTSZINHERIT)
 664			flags |= FS_XFLAG_EXTSZINHERIT;
 665		if (di_flags & XFS_DIFLAG_NODEFRAG)
 666			flags |= FS_XFLAG_NODEFRAG;
 667		if (di_flags & XFS_DIFLAG_FILESTREAM)
 668			flags |= FS_XFLAG_FILESTREAM;
 669	}
 670
 671	if (di_flags2 & XFS_DIFLAG2_ANY) {
 672		if (di_flags2 & XFS_DIFLAG2_DAX)
 673			flags |= FS_XFLAG_DAX;
 674		if (di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
 675			flags |= FS_XFLAG_COWEXTSIZE;
 676	}
 677
 678	if (has_attr)
 679		flags |= FS_XFLAG_HASATTR;
 680
 681	return flags;
 682}
 683
 684uint
 685xfs_ip2xflags(
 686	struct xfs_inode	*ip)
 687{
 688	struct xfs_icdinode	*dic = &ip->i_d;
 689
 690	return _xfs_dic2xflags(dic->di_flags, dic->di_flags2, XFS_IFORK_Q(ip));
 691}
 692
 693/*
 694 * Lookups up an inode from "name". If ci_name is not NULL, then a CI match
 695 * is allowed, otherwise it has to be an exact match. If a CI match is found,
 696 * ci_name->name will point to a the actual name (caller must free) or
 697 * will be set to NULL if an exact match is found.
 698 */
 699int
 700xfs_lookup(
 701	xfs_inode_t		*dp,
 702	struct xfs_name		*name,
 703	xfs_inode_t		**ipp,
 704	struct xfs_name		*ci_name)
 705{
 706	xfs_ino_t		inum;
 707	int			error;
 708
 709	trace_xfs_lookup(dp, name);
 710
 711	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
 712		return -EIO;
 713
 714	error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
 715	if (error)
 716		goto out_unlock;
 717
 718	error = xfs_iget(dp->i_mount, NULL, inum, 0, 0, ipp);
 719	if (error)
 720		goto out_free_name;
 721
 722	return 0;
 723
 724out_free_name:
 725	if (ci_name)
 726		kmem_free(ci_name->name);
 727out_unlock:
 728	*ipp = NULL;
 729	return error;
 730}
 731
 732/*
 733 * Allocate an inode on disk and return a copy of its in-core version.
 734 * The in-core inode is locked exclusively.  Set mode, nlink, and rdev
 735 * appropriately within the inode.  The uid and gid for the inode are
 736 * set according to the contents of the given cred structure.
 737 *
 738 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
 739 * has a free inode available, call xfs_iget() to obtain the in-core
 740 * version of the allocated inode.  Finally, fill in the inode and
 741 * log its initial contents.  In this case, ialloc_context would be
 742 * set to NULL.
 743 *
 744 * If xfs_dialloc() does not have an available inode, it will replenish
 745 * its supply by doing an allocation. Since we can only do one
 746 * allocation within a transaction without deadlocks, we must commit
 747 * the current transaction before returning the inode itself.
 748 * In this case, therefore, we will set ialloc_context and return.
 749 * The caller should then commit the current transaction, start a new
 750 * transaction, and call xfs_ialloc() again to actually get the inode.
 751 *
 752 * To ensure that some other process does not grab the inode that
 753 * was allocated during the first call to xfs_ialloc(), this routine
 754 * also returns the [locked] bp pointing to the head of the freelist
 755 * as ialloc_context.  The caller should hold this buffer across
 756 * the commit and pass it back into this routine on the second call.
 757 *
 758 * If we are allocating quota inodes, we do not have a parent inode
 759 * to attach to or associate with (i.e. pip == NULL) because they
 760 * are not linked into the directory structure - they are attached
 761 * directly to the superblock - and so have no parent.
 762 */
 763static int
 764xfs_ialloc(
 765	xfs_trans_t	*tp,
 766	xfs_inode_t	*pip,
 767	umode_t		mode,
 768	xfs_nlink_t	nlink,
 769	xfs_dev_t	rdev,
 770	prid_t		prid,
 771	int		okalloc,
 772	xfs_buf_t	**ialloc_context,
 773	xfs_inode_t	**ipp)
 774{
 775	struct xfs_mount *mp = tp->t_mountp;
 776	xfs_ino_t	ino;
 777	xfs_inode_t	*ip;
 778	uint		flags;
 779	int		error;
 780	struct timespec	tv;
 781	struct inode	*inode;
 782
 783	/*
 784	 * Call the space management code to pick
 785	 * the on-disk inode to be allocated.
 786	 */
 787	error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode, okalloc,
 788			    ialloc_context, &ino);
 789	if (error)
 790		return error;
 791	if (*ialloc_context || ino == NULLFSINO) {
 792		*ipp = NULL;
 793		return 0;
 794	}
 795	ASSERT(*ialloc_context == NULL);
 796
 797	/*
 
 
 
 
 
 
 
 
 
 
 
 
 798	 * Get the in-core inode with the lock held exclusively.
 799	 * This is because we're setting fields here we need
 800	 * to prevent others from looking at until we're done.
 801	 */
 802	error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE,
 803			 XFS_ILOCK_EXCL, &ip);
 804	if (error)
 805		return error;
 806	ASSERT(ip != NULL);
 807	inode = VFS_I(ip);
 808
 809	/*
 810	 * We always convert v1 inodes to v2 now - we only support filesystems
 811	 * with >= v2 inode capability, so there is no reason for ever leaving
 812	 * an inode in v1 format.
 813	 */
 814	if (ip->i_d.di_version == 1)
 815		ip->i_d.di_version = 2;
 816
 817	inode->i_mode = mode;
 818	set_nlink(inode, nlink);
 819	ip->i_d.di_uid = xfs_kuid_to_uid(current_fsuid());
 820	ip->i_d.di_gid = xfs_kgid_to_gid(current_fsgid());
 
 821	xfs_set_projid(ip, prid);
 822
 823	if (pip && XFS_INHERIT_GID(pip)) {
 824		ip->i_d.di_gid = pip->i_d.di_gid;
 825		if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode))
 826			inode->i_mode |= S_ISGID;
 827	}
 828
 829	/*
 830	 * If the group ID of the new file does not match the effective group
 831	 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
 832	 * (and only if the irix_sgid_inherit compatibility variable is set).
 833	 */
 834	if ((irix_sgid_inherit) &&
 835	    (inode->i_mode & S_ISGID) &&
 836	    (!in_group_p(xfs_gid_to_kgid(ip->i_d.di_gid))))
 837		inode->i_mode &= ~S_ISGID;
 838
 839	ip->i_d.di_size = 0;
 840	ip->i_d.di_nextents = 0;
 841	ASSERT(ip->i_d.di_nblocks == 0);
 842
 843	tv = current_time(inode);
 844	inode->i_mtime = tv;
 845	inode->i_atime = tv;
 846	inode->i_ctime = tv;
 847
 848	ip->i_d.di_extsize = 0;
 849	ip->i_d.di_dmevmask = 0;
 850	ip->i_d.di_dmstate = 0;
 851	ip->i_d.di_flags = 0;
 852
 853	if (ip->i_d.di_version == 3) {
 854		inode->i_version = 1;
 855		ip->i_d.di_flags2 = 0;
 856		ip->i_d.di_cowextsize = 0;
 857		ip->i_d.di_crtime.t_sec = (__int32_t)tv.tv_sec;
 858		ip->i_d.di_crtime.t_nsec = (__int32_t)tv.tv_nsec;
 859	}
 860
 861
 862	flags = XFS_ILOG_CORE;
 863	switch (mode & S_IFMT) {
 864	case S_IFIFO:
 865	case S_IFCHR:
 866	case S_IFBLK:
 867	case S_IFSOCK:
 868		ip->i_d.di_format = XFS_DINODE_FMT_DEV;
 869		ip->i_df.if_u2.if_rdev = rdev;
 870		ip->i_df.if_flags = 0;
 871		flags |= XFS_ILOG_DEV;
 872		break;
 873	case S_IFREG:
 874	case S_IFDIR:
 875		if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
 876			uint64_t	di_flags2 = 0;
 877			uint		di_flags = 0;
 878
 879			if (S_ISDIR(mode)) {
 880				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
 881					di_flags |= XFS_DIFLAG_RTINHERIT;
 882				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
 883					di_flags |= XFS_DIFLAG_EXTSZINHERIT;
 884					ip->i_d.di_extsize = pip->i_d.di_extsize;
 885				}
 886				if (pip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
 887					di_flags |= XFS_DIFLAG_PROJINHERIT;
 888			} else if (S_ISREG(mode)) {
 889				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
 890					di_flags |= XFS_DIFLAG_REALTIME;
 891				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
 892					di_flags |= XFS_DIFLAG_EXTSIZE;
 893					ip->i_d.di_extsize = pip->i_d.di_extsize;
 894				}
 895			}
 896			if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
 897			    xfs_inherit_noatime)
 898				di_flags |= XFS_DIFLAG_NOATIME;
 899			if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
 900			    xfs_inherit_nodump)
 901				di_flags |= XFS_DIFLAG_NODUMP;
 902			if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
 903			    xfs_inherit_sync)
 904				di_flags |= XFS_DIFLAG_SYNC;
 905			if ((pip->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) &&
 906			    xfs_inherit_nosymlinks)
 907				di_flags |= XFS_DIFLAG_NOSYMLINKS;
 908			if ((pip->i_d.di_flags & XFS_DIFLAG_NODEFRAG) &&
 909			    xfs_inherit_nodefrag)
 910				di_flags |= XFS_DIFLAG_NODEFRAG;
 911			if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
 912				di_flags |= XFS_DIFLAG_FILESTREAM;
 913			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
 914				di_flags2 |= XFS_DIFLAG2_DAX;
 915
 916			ip->i_d.di_flags |= di_flags;
 917			ip->i_d.di_flags2 |= di_flags2;
 918		}
 919		if (pip &&
 920		    (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY) &&
 921		    pip->i_d.di_version == 3 &&
 922		    ip->i_d.di_version == 3) {
 
 
 923			if (pip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) {
 924				ip->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
 925				ip->i_d.di_cowextsize = pip->i_d.di_cowextsize;
 926			}
 
 
 
 
 927		}
 928		/* FALLTHROUGH */
 929	case S_IFLNK:
 930		ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
 931		ip->i_df.if_flags = XFS_IFEXTENTS;
 932		ip->i_df.if_bytes = ip->i_df.if_real_bytes = 0;
 933		ip->i_df.if_u1.if_extents = NULL;
 934		break;
 935	default:
 936		ASSERT(0);
 937	}
 938	/*
 939	 * Attribute fork settings for new inode.
 940	 */
 941	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
 942	ip->i_d.di_anextents = 0;
 943
 944	/*
 945	 * Log the new values stuffed into the inode.
 946	 */
 947	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 948	xfs_trans_log_inode(tp, ip, flags);
 949
 950	/* now that we have an i_mode we can setup the inode structure */
 951	xfs_setup_inode(ip);
 952
 953	*ipp = ip;
 954	return 0;
 955}
 956
 957/*
 958 * Allocates a new inode from disk and return a pointer to the
 959 * incore copy. This routine will internally commit the current
 960 * transaction and allocate a new one if the Space Manager needed
 961 * to do an allocation to replenish the inode free-list.
 962 *
 963 * This routine is designed to be called from xfs_create and
 964 * xfs_create_dir.
 965 *
 966 */
 967int
 968xfs_dir_ialloc(
 969	xfs_trans_t	**tpp,		/* input: current transaction;
 970					   output: may be a new transaction. */
 971	xfs_inode_t	*dp,		/* directory within whose allocate
 972					   the inode. */
 973	umode_t		mode,
 974	xfs_nlink_t	nlink,
 975	xfs_dev_t	rdev,
 976	prid_t		prid,		/* project id */
 977	int		okalloc,	/* ok to allocate new space */
 978	xfs_inode_t	**ipp,		/* pointer to inode; it will be
 979					   locked. */
 980	int		*committed)
 981
 982{
 983	xfs_trans_t	*tp;
 984	xfs_inode_t	*ip;
 985	xfs_buf_t	*ialloc_context = NULL;
 986	int		code;
 987	void		*dqinfo;
 988	uint		tflags;
 989
 990	tp = *tpp;
 991	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
 992
 993	/*
 994	 * xfs_ialloc will return a pointer to an incore inode if
 995	 * the Space Manager has an available inode on the free
 996	 * list. Otherwise, it will do an allocation and replenish
 997	 * the freelist.  Since we can only do one allocation per
 998	 * transaction without deadlocks, we will need to commit the
 999	 * current transaction and start a new one.  We will then
1000	 * need to call xfs_ialloc again to get the inode.
1001	 *
1002	 * If xfs_ialloc did an allocation to replenish the freelist,
1003	 * it returns the bp containing the head of the freelist as
1004	 * ialloc_context. We will hold a lock on it across the
1005	 * transaction commit so that no other process can steal
1006	 * the inode(s) that we've just allocated.
1007	 */
1008	code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, okalloc,
1009			  &ialloc_context, &ip);
1010
1011	/*
1012	 * Return an error if we were unable to allocate a new inode.
1013	 * This should only happen if we run out of space on disk or
1014	 * encounter a disk error.
1015	 */
1016	if (code) {
1017		*ipp = NULL;
1018		return code;
1019	}
1020	if (!ialloc_context && !ip) {
1021		*ipp = NULL;
1022		return -ENOSPC;
1023	}
1024
1025	/*
1026	 * If the AGI buffer is non-NULL, then we were unable to get an
1027	 * inode in one operation.  We need to commit the current
1028	 * transaction and call xfs_ialloc() again.  It is guaranteed
1029	 * to succeed the second time.
1030	 */
1031	if (ialloc_context) {
1032		/*
1033		 * Normally, xfs_trans_commit releases all the locks.
1034		 * We call bhold to hang on to the ialloc_context across
1035		 * the commit.  Holding this buffer prevents any other
1036		 * processes from doing any allocations in this
1037		 * allocation group.
1038		 */
1039		xfs_trans_bhold(tp, ialloc_context);
1040
1041		/*
1042		 * We want the quota changes to be associated with the next
1043		 * transaction, NOT this one. So, detach the dqinfo from this
1044		 * and attach it to the next transaction.
1045		 */
1046		dqinfo = NULL;
1047		tflags = 0;
1048		if (tp->t_dqinfo) {
1049			dqinfo = (void *)tp->t_dqinfo;
1050			tp->t_dqinfo = NULL;
1051			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
1052			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
1053		}
1054
1055		code = xfs_trans_roll(&tp, NULL);
1056		if (committed != NULL)
1057			*committed = 1;
1058
1059		/*
1060		 * Re-attach the quota info that we detached from prev trx.
1061		 */
1062		if (dqinfo) {
1063			tp->t_dqinfo = dqinfo;
1064			tp->t_flags |= tflags;
1065		}
1066
1067		if (code) {
1068			xfs_buf_relse(ialloc_context);
1069			*tpp = tp;
1070			*ipp = NULL;
1071			return code;
1072		}
1073		xfs_trans_bjoin(tp, ialloc_context);
1074
1075		/*
1076		 * Call ialloc again. Since we've locked out all
1077		 * other allocations in this allocation group,
1078		 * this call should always succeed.
1079		 */
1080		code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
1081				  okalloc, &ialloc_context, &ip);
1082
1083		/*
1084		 * If we get an error at this point, return to the caller
1085		 * so that the current transaction can be aborted.
1086		 */
1087		if (code) {
1088			*tpp = tp;
1089			*ipp = NULL;
1090			return code;
1091		}
1092		ASSERT(!ialloc_context && ip);
1093
1094	} else {
1095		if (committed != NULL)
1096			*committed = 0;
1097	}
1098
1099	*ipp = ip;
1100	*tpp = tp;
1101
1102	return 0;
1103}
1104
1105/*
1106 * Decrement the link count on an inode & log the change.  If this causes the
1107 * link count to go to zero, move the inode to AGI unlinked list so that it can
1108 * be freed when the last active reference goes away via xfs_inactive().
1109 */
1110static int			/* error */
1111xfs_droplink(
1112	xfs_trans_t *tp,
1113	xfs_inode_t *ip)
1114{
1115	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1116
1117	drop_nlink(VFS_I(ip));
1118	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1119
1120	if (VFS_I(ip)->i_nlink)
1121		return 0;
1122
1123	return xfs_iunlink(tp, ip);
1124}
1125
1126/*
1127 * Increment the link count on an inode & log the change.
1128 */
1129static int
1130xfs_bumplink(
1131	xfs_trans_t *tp,
1132	xfs_inode_t *ip)
1133{
1134	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1135
1136	ASSERT(ip->i_d.di_version > 1);
1137	inc_nlink(VFS_I(ip));
1138	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1139	return 0;
1140}
1141
1142int
1143xfs_create(
1144	xfs_inode_t		*dp,
1145	struct xfs_name		*name,
1146	umode_t			mode,
1147	xfs_dev_t		rdev,
1148	xfs_inode_t		**ipp)
1149{
1150	int			is_dir = S_ISDIR(mode);
1151	struct xfs_mount	*mp = dp->i_mount;
1152	struct xfs_inode	*ip = NULL;
1153	struct xfs_trans	*tp = NULL;
1154	int			error;
1155	struct xfs_defer_ops	dfops;
1156	xfs_fsblock_t		first_block;
1157	bool                    unlock_dp_on_error = false;
1158	prid_t			prid;
1159	struct xfs_dquot	*udqp = NULL;
1160	struct xfs_dquot	*gdqp = NULL;
1161	struct xfs_dquot	*pdqp = NULL;
1162	struct xfs_trans_res	*tres;
1163	uint			resblks;
1164
1165	trace_xfs_create(dp, name);
1166
1167	if (XFS_FORCED_SHUTDOWN(mp))
1168		return -EIO;
1169
1170	prid = xfs_get_initial_prid(dp);
1171
1172	/*
1173	 * Make sure that we have allocated dquot(s) on disk.
1174	 */
1175	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1176					xfs_kgid_to_gid(current_fsgid()), prid,
1177					XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1178					&udqp, &gdqp, &pdqp);
1179	if (error)
1180		return error;
1181
1182	if (is_dir) {
1183		rdev = 0;
1184		resblks = XFS_MKDIR_SPACE_RES(mp, name->len);
1185		tres = &M_RES(mp)->tr_mkdir;
1186	} else {
1187		resblks = XFS_CREATE_SPACE_RES(mp, name->len);
1188		tres = &M_RES(mp)->tr_create;
1189	}
1190
1191	/*
1192	 * Initially assume that the file does not exist and
1193	 * reserve the resources for that case.  If that is not
1194	 * the case we'll drop the one we have and get a more
1195	 * appropriate transaction later.
1196	 */
1197	error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1198	if (error == -ENOSPC) {
1199		/* flush outstanding delalloc blocks and retry */
1200		xfs_flush_inodes(mp);
1201		error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1202	}
1203	if (error == -ENOSPC) {
1204		/* No space at all so try a "no-allocation" reservation */
1205		resblks = 0;
1206		error = xfs_trans_alloc(mp, tres, 0, 0, 0, &tp);
1207	}
1208	if (error)
1209		goto out_release_inode;
1210
1211	xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
1212	unlock_dp_on_error = true;
1213
1214	xfs_defer_init(&dfops, &first_block);
1215
1216	/*
1217	 * Reserve disk quota and the inode.
1218	 */
1219	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1220						pdqp, resblks, 1, 0);
1221	if (error)
1222		goto out_trans_cancel;
1223
1224	if (!resblks) {
1225		error = xfs_dir_canenter(tp, dp, name);
1226		if (error)
1227			goto out_trans_cancel;
1228	}
1229
1230	/*
1231	 * A newly created regular or special file just has one directory
1232	 * entry pointing to them, but a directory also the "." entry
1233	 * pointing to itself.
1234	 */
1235	error = xfs_dir_ialloc(&tp, dp, mode, is_dir ? 2 : 1, rdev,
1236			       prid, resblks > 0, &ip, NULL);
1237	if (error)
1238		goto out_trans_cancel;
1239
1240	/*
1241	 * Now we join the directory inode to the transaction.  We do not do it
1242	 * earlier because xfs_dir_ialloc might commit the previous transaction
1243	 * (and release all the locks).  An error from here on will result in
1244	 * the transaction cancel unlocking dp so don't do it explicitly in the
1245	 * error path.
1246	 */
1247	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
1248	unlock_dp_on_error = false;
1249
1250	error = xfs_dir_createname(tp, dp, name, ip->i_ino,
1251					&first_block, &dfops, resblks ?
1252					resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
1253	if (error) {
1254		ASSERT(error != -ENOSPC);
1255		goto out_trans_cancel;
1256	}
1257	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1258	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1259
1260	if (is_dir) {
1261		error = xfs_dir_init(tp, ip, dp);
1262		if (error)
1263			goto out_bmap_cancel;
1264
1265		error = xfs_bumplink(tp, dp);
1266		if (error)
1267			goto out_bmap_cancel;
1268	}
1269
1270	/*
1271	 * If this is a synchronous mount, make sure that the
1272	 * create transaction goes to disk before returning to
1273	 * the user.
1274	 */
1275	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1276		xfs_trans_set_sync(tp);
1277
1278	/*
1279	 * Attach the dquot(s) to the inodes and modify them incore.
1280	 * These ids of the inode couldn't have changed since the new
1281	 * inode has been locked ever since it was created.
1282	 */
1283	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1284
1285	error = xfs_defer_finish(&tp, &dfops, NULL);
1286	if (error)
1287		goto out_bmap_cancel;
1288
1289	error = xfs_trans_commit(tp);
1290	if (error)
1291		goto out_release_inode;
1292
1293	xfs_qm_dqrele(udqp);
1294	xfs_qm_dqrele(gdqp);
1295	xfs_qm_dqrele(pdqp);
1296
1297	*ipp = ip;
1298	return 0;
1299
1300 out_bmap_cancel:
1301	xfs_defer_cancel(&dfops);
1302 out_trans_cancel:
1303	xfs_trans_cancel(tp);
1304 out_release_inode:
1305	/*
1306	 * Wait until after the current transaction is aborted to finish the
1307	 * setup of the inode and release the inode.  This prevents recursive
1308	 * transactions and deadlocks from xfs_inactive.
1309	 */
1310	if (ip) {
1311		xfs_finish_inode_setup(ip);
1312		IRELE(ip);
1313	}
1314
1315	xfs_qm_dqrele(udqp);
1316	xfs_qm_dqrele(gdqp);
1317	xfs_qm_dqrele(pdqp);
1318
1319	if (unlock_dp_on_error)
1320		xfs_iunlock(dp, XFS_ILOCK_EXCL);
1321	return error;
1322}
1323
1324int
1325xfs_create_tmpfile(
1326	struct xfs_inode	*dp,
1327	struct dentry		*dentry,
1328	umode_t			mode,
1329	struct xfs_inode	**ipp)
1330{
1331	struct xfs_mount	*mp = dp->i_mount;
1332	struct xfs_inode	*ip = NULL;
1333	struct xfs_trans	*tp = NULL;
1334	int			error;
1335	prid_t                  prid;
1336	struct xfs_dquot	*udqp = NULL;
1337	struct xfs_dquot	*gdqp = NULL;
1338	struct xfs_dquot	*pdqp = NULL;
1339	struct xfs_trans_res	*tres;
1340	uint			resblks;
1341
1342	if (XFS_FORCED_SHUTDOWN(mp))
1343		return -EIO;
1344
1345	prid = xfs_get_initial_prid(dp);
1346
1347	/*
1348	 * Make sure that we have allocated dquot(s) on disk.
1349	 */
1350	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1351				xfs_kgid_to_gid(current_fsgid()), prid,
1352				XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1353				&udqp, &gdqp, &pdqp);
1354	if (error)
1355		return error;
1356
1357	resblks = XFS_IALLOC_SPACE_RES(mp);
1358	tres = &M_RES(mp)->tr_create_tmpfile;
1359
1360	error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1361	if (error == -ENOSPC) {
1362		/* No space at all so try a "no-allocation" reservation */
1363		resblks = 0;
1364		error = xfs_trans_alloc(mp, tres, 0, 0, 0, &tp);
1365	}
1366	if (error)
1367		goto out_release_inode;
1368
1369	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1370						pdqp, resblks, 1, 0);
1371	if (error)
1372		goto out_trans_cancel;
1373
1374	error = xfs_dir_ialloc(&tp, dp, mode, 1, 0,
1375				prid, resblks > 0, &ip, NULL);
1376	if (error)
1377		goto out_trans_cancel;
1378
1379	if (mp->m_flags & XFS_MOUNT_WSYNC)
1380		xfs_trans_set_sync(tp);
1381
1382	/*
1383	 * Attach the dquot(s) to the inodes and modify them incore.
1384	 * These ids of the inode couldn't have changed since the new
1385	 * inode has been locked ever since it was created.
1386	 */
1387	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1388
1389	error = xfs_iunlink(tp, ip);
1390	if (error)
1391		goto out_trans_cancel;
1392
1393	error = xfs_trans_commit(tp);
1394	if (error)
1395		goto out_release_inode;
1396
1397	xfs_qm_dqrele(udqp);
1398	xfs_qm_dqrele(gdqp);
1399	xfs_qm_dqrele(pdqp);
1400
1401	*ipp = ip;
1402	return 0;
1403
1404 out_trans_cancel:
1405	xfs_trans_cancel(tp);
1406 out_release_inode:
1407	/*
1408	 * Wait until after the current transaction is aborted to finish the
1409	 * setup of the inode and release the inode.  This prevents recursive
1410	 * transactions and deadlocks from xfs_inactive.
1411	 */
1412	if (ip) {
1413		xfs_finish_inode_setup(ip);
1414		IRELE(ip);
1415	}
1416
1417	xfs_qm_dqrele(udqp);
1418	xfs_qm_dqrele(gdqp);
1419	xfs_qm_dqrele(pdqp);
1420
1421	return error;
1422}
1423
1424int
1425xfs_link(
1426	xfs_inode_t		*tdp,
1427	xfs_inode_t		*sip,
1428	struct xfs_name		*target_name)
1429{
1430	xfs_mount_t		*mp = tdp->i_mount;
1431	xfs_trans_t		*tp;
1432	int			error;
1433	struct xfs_defer_ops	dfops;
1434	xfs_fsblock_t           first_block;
1435	int			resblks;
1436
1437	trace_xfs_link(tdp, target_name);
1438
1439	ASSERT(!S_ISDIR(VFS_I(sip)->i_mode));
1440
1441	if (XFS_FORCED_SHUTDOWN(mp))
1442		return -EIO;
1443
1444	error = xfs_qm_dqattach(sip, 0);
1445	if (error)
1446		goto std_return;
1447
1448	error = xfs_qm_dqattach(tdp, 0);
1449	if (error)
1450		goto std_return;
1451
1452	resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
1453	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, resblks, 0, 0, &tp);
1454	if (error == -ENOSPC) {
1455		resblks = 0;
1456		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, 0, 0, 0, &tp);
1457	}
1458	if (error)
1459		goto std_return;
1460
1461	xfs_lock_two_inodes(sip, tdp, XFS_ILOCK_EXCL);
1462
1463	xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
1464	xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
1465
1466	/*
1467	 * If we are using project inheritance, we only allow hard link
1468	 * creation in our tree when the project IDs are the same; else
1469	 * the tree quota mechanism could be circumvented.
1470	 */
1471	if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
1472		     (xfs_get_projid(tdp) != xfs_get_projid(sip)))) {
1473		error = -EXDEV;
1474		goto error_return;
1475	}
1476
1477	if (!resblks) {
1478		error = xfs_dir_canenter(tp, tdp, target_name);
1479		if (error)
1480			goto error_return;
1481	}
1482
1483	xfs_defer_init(&dfops, &first_block);
1484
1485	/*
1486	 * Handle initial link state of O_TMPFILE inode
1487	 */
1488	if (VFS_I(sip)->i_nlink == 0) {
1489		error = xfs_iunlink_remove(tp, sip);
1490		if (error)
1491			goto error_return;
1492	}
1493
1494	error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
1495					&first_block, &dfops, resblks);
1496	if (error)
1497		goto error_return;
1498	xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1499	xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
1500
1501	error = xfs_bumplink(tp, sip);
1502	if (error)
1503		goto error_return;
1504
1505	/*
1506	 * If this is a synchronous mount, make sure that the
1507	 * link transaction goes to disk before returning to
1508	 * the user.
1509	 */
1510	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1511		xfs_trans_set_sync(tp);
1512
1513	error = xfs_defer_finish(&tp, &dfops, NULL);
1514	if (error) {
1515		xfs_defer_cancel(&dfops);
1516		goto error_return;
1517	}
1518
1519	return xfs_trans_commit(tp);
1520
1521 error_return:
1522	xfs_trans_cancel(tp);
1523 std_return:
1524	return error;
1525}
1526
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1527/*
1528 * Free up the underlying blocks past new_size.  The new size must be smaller
1529 * than the current size.  This routine can be used both for the attribute and
1530 * data fork, and does not modify the inode size, which is left to the caller.
1531 *
1532 * The transaction passed to this routine must have made a permanent log
1533 * reservation of at least XFS_ITRUNCATE_LOG_RES.  This routine may commit the
1534 * given transaction and start new ones, so make sure everything involved in
1535 * the transaction is tidy before calling here.  Some transaction will be
1536 * returned to the caller to be committed.  The incoming transaction must
1537 * already include the inode, and both inode locks must be held exclusively.
1538 * The inode must also be "held" within the transaction.  On return the inode
1539 * will be "held" within the returned transaction.  This routine does NOT
1540 * require any disk space to be reserved for it within the transaction.
1541 *
1542 * If we get an error, we must return with the inode locked and linked into the
1543 * current transaction. This keeps things simple for the higher level code,
1544 * because it always knows that the inode is locked and held in the transaction
1545 * that returns to it whether errors occur or not.  We don't mark the inode
1546 * dirty on error so that transactions can be easily aborted if possible.
1547 */
1548int
1549xfs_itruncate_extents(
1550	struct xfs_trans	**tpp,
1551	struct xfs_inode	*ip,
1552	int			whichfork,
1553	xfs_fsize_t		new_size)
 
1554{
1555	struct xfs_mount	*mp = ip->i_mount;
1556	struct xfs_trans	*tp = *tpp;
1557	struct xfs_defer_ops	dfops;
1558	xfs_fsblock_t		first_block;
1559	xfs_fileoff_t		first_unmap_block;
1560	xfs_fileoff_t		last_block;
1561	xfs_filblks_t		unmap_len;
1562	int			error = 0;
1563	int			done = 0;
1564
1565	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1566	ASSERT(!atomic_read(&VFS_I(ip)->i_count) ||
1567	       xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1568	ASSERT(new_size <= XFS_ISIZE(ip));
1569	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
1570	ASSERT(ip->i_itemp != NULL);
1571	ASSERT(ip->i_itemp->ili_lock_flags == 0);
1572	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1573
1574	trace_xfs_itruncate_extents_start(ip, new_size);
1575
 
 
1576	/*
1577	 * Since it is possible for space to become allocated beyond
1578	 * the end of the file (in a crash where the space is allocated
1579	 * but the inode size is not yet updated), simply remove any
1580	 * blocks which show up between the new EOF and the maximum
1581	 * possible file size.  If the first block to be removed is
1582	 * beyond the maximum file size (ie it is the same as last_block),
1583	 * then there is nothing to do.
1584	 */
1585	first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
1586	last_block = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
1587	if (first_unmap_block == last_block)
1588		return 0;
1589
1590	ASSERT(first_unmap_block < last_block);
1591	unmap_len = last_block - first_unmap_block + 1;
1592	while (!done) {
1593		xfs_defer_init(&dfops, &first_block);
1594		error = xfs_bunmapi(tp, ip,
1595				    first_unmap_block, unmap_len,
1596				    xfs_bmapi_aflag(whichfork),
1597				    XFS_ITRUNC_MAX_EXTENTS,
1598				    &first_block, &dfops,
1599				    &done);
1600		if (error)
1601			goto out_bmap_cancel;
1602
1603		/*
1604		 * Duplicate the transaction that has the permanent
1605		 * reservation and commit the old transaction.
1606		 */
1607		error = xfs_defer_finish(&tp, &dfops, ip);
1608		if (error)
1609			goto out_bmap_cancel;
1610
1611		error = xfs_trans_roll(&tp, ip);
1612		if (error)
1613			goto out;
1614	}
1615
1616	/* Remove all pending CoW reservations. */
1617	error = xfs_reflink_cancel_cow_blocks(ip, &tp, first_unmap_block,
1618			last_block, true);
1619	if (error)
1620		goto out;
 
1621
1622	/*
1623	 * Clear the reflink flag if we truncated everything.
1624	 */
1625	if (ip->i_d.di_nblocks == 0 && xfs_is_reflink_inode(ip)) {
1626		ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
1627		xfs_inode_clear_cowblocks_tag(ip);
1628	}
1629
1630	/*
1631	 * Always re-log the inode so that our permanent transaction can keep
1632	 * on rolling it forward in the log.
1633	 */
1634	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1635
1636	trace_xfs_itruncate_extents_end(ip, new_size);
1637
1638out:
1639	*tpp = tp;
1640	return error;
1641out_bmap_cancel:
1642	/*
1643	 * If the bunmapi call encounters an error, return to the caller where
1644	 * the transaction can be properly aborted.  We just need to make sure
1645	 * we're not holding any resources that we were not when we came in.
1646	 */
1647	xfs_defer_cancel(&dfops);
1648	goto out;
1649}
1650
1651int
1652xfs_release(
1653	xfs_inode_t	*ip)
1654{
1655	xfs_mount_t	*mp = ip->i_mount;
1656	int		error;
1657
1658	if (!S_ISREG(VFS_I(ip)->i_mode) || (VFS_I(ip)->i_mode == 0))
1659		return 0;
1660
1661	/* If this is a read-only mount, don't do this (would generate I/O) */
1662	if (mp->m_flags & XFS_MOUNT_RDONLY)
1663		return 0;
1664
1665	if (!XFS_FORCED_SHUTDOWN(mp)) {
1666		int truncated;
1667
1668		/*
1669		 * If we previously truncated this file and removed old data
1670		 * in the process, we want to initiate "early" writeout on
1671		 * the last close.  This is an attempt to combat the notorious
1672		 * NULL files problem which is particularly noticeable from a
1673		 * truncate down, buffered (re-)write (delalloc), followed by
1674		 * a crash.  What we are effectively doing here is
1675		 * significantly reducing the time window where we'd otherwise
1676		 * be exposed to that problem.
1677		 */
1678		truncated = xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED);
1679		if (truncated) {
1680			xfs_iflags_clear(ip, XFS_IDIRTY_RELEASE);
1681			if (ip->i_delayed_blks > 0) {
1682				error = filemap_flush(VFS_I(ip)->i_mapping);
1683				if (error)
1684					return error;
1685			}
1686		}
1687	}
1688
1689	if (VFS_I(ip)->i_nlink == 0)
1690		return 0;
1691
1692	if (xfs_can_free_eofblocks(ip, false)) {
1693
1694		/*
1695		 * Check if the inode is being opened, written and closed
1696		 * frequently and we have delayed allocation blocks outstanding
1697		 * (e.g. streaming writes from the NFS server), truncating the
1698		 * blocks past EOF will cause fragmentation to occur.
1699		 *
1700		 * In this case don't do the truncation, but we have to be
1701		 * careful how we detect this case. Blocks beyond EOF show up as
1702		 * i_delayed_blks even when the inode is clean, so we need to
1703		 * truncate them away first before checking for a dirty release.
1704		 * Hence on the first dirty close we will still remove the
1705		 * speculative allocation, but after that we will leave it in
1706		 * place.
1707		 */
1708		if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
1709			return 0;
1710		/*
1711		 * If we can't get the iolock just skip truncating the blocks
1712		 * past EOF because we could deadlock with the mmap_sem
1713		 * otherwise. We'll get another chance to drop them once the
1714		 * last reference to the inode is dropped, so we'll never leak
1715		 * blocks permanently.
1716		 */
1717		if (xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1718			error = xfs_free_eofblocks(ip);
1719			xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1720			if (error)
1721				return error;
1722		}
1723
1724		/* delalloc blocks after truncation means it really is dirty */
1725		if (ip->i_delayed_blks)
1726			xfs_iflags_set(ip, XFS_IDIRTY_RELEASE);
1727	}
1728	return 0;
1729}
1730
1731/*
1732 * xfs_inactive_truncate
1733 *
1734 * Called to perform a truncate when an inode becomes unlinked.
1735 */
1736STATIC int
1737xfs_inactive_truncate(
1738	struct xfs_inode *ip)
1739{
1740	struct xfs_mount	*mp = ip->i_mount;
1741	struct xfs_trans	*tp;
1742	int			error;
1743
1744	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
1745	if (error) {
1746		ASSERT(XFS_FORCED_SHUTDOWN(mp));
1747		return error;
1748	}
1749
1750	xfs_ilock(ip, XFS_ILOCK_EXCL);
1751	xfs_trans_ijoin(tp, ip, 0);
1752
1753	/*
1754	 * Log the inode size first to prevent stale data exposure in the event
1755	 * of a system crash before the truncate completes. See the related
1756	 * comment in xfs_vn_setattr_size() for details.
1757	 */
1758	ip->i_d.di_size = 0;
1759	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1760
1761	error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
1762	if (error)
1763		goto error_trans_cancel;
1764
1765	ASSERT(ip->i_d.di_nextents == 0);
1766
1767	error = xfs_trans_commit(tp);
1768	if (error)
1769		goto error_unlock;
1770
1771	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1772	return 0;
1773
1774error_trans_cancel:
1775	xfs_trans_cancel(tp);
1776error_unlock:
1777	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1778	return error;
1779}
1780
1781/*
1782 * xfs_inactive_ifree()
1783 *
1784 * Perform the inode free when an inode is unlinked.
1785 */
1786STATIC int
1787xfs_inactive_ifree(
1788	struct xfs_inode *ip)
1789{
1790	struct xfs_defer_ops	dfops;
1791	xfs_fsblock_t		first_block;
1792	struct xfs_mount	*mp = ip->i_mount;
1793	struct xfs_trans	*tp;
1794	int			error;
1795
1796	/*
1797	 * We try to use a per-AG reservation for any block needed by the finobt
1798	 * tree, but as the finobt feature predates the per-AG reservation
1799	 * support a degraded file system might not have enough space for the
1800	 * reservation at mount time.  In that case try to dip into the reserved
1801	 * pool and pray.
1802	 *
1803	 * Send a warning if the reservation does happen to fail, as the inode
1804	 * now remains allocated and sits on the unlinked list until the fs is
1805	 * repaired.
1806	 */
1807	if (unlikely(mp->m_inotbt_nores)) {
1808		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree,
1809				XFS_IFREE_SPACE_RES(mp), 0, XFS_TRANS_RESERVE,
1810				&tp);
1811	} else {
1812		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree, 0, 0, 0, &tp);
1813	}
1814	if (error) {
1815		if (error == -ENOSPC) {
1816			xfs_warn_ratelimited(mp,
1817			"Failed to remove inode(s) from unlinked list. "
1818			"Please free space, unmount and run xfs_repair.");
1819		} else {
1820			ASSERT(XFS_FORCED_SHUTDOWN(mp));
1821		}
1822		return error;
1823	}
1824
1825	xfs_ilock(ip, XFS_ILOCK_EXCL);
1826	xfs_trans_ijoin(tp, ip, 0);
1827
1828	xfs_defer_init(&dfops, &first_block);
1829	error = xfs_ifree(tp, ip, &dfops);
1830	if (error) {
1831		/*
1832		 * If we fail to free the inode, shut down.  The cancel
1833		 * might do that, we need to make sure.  Otherwise the
1834		 * inode might be lost for a long time or forever.
1835		 */
1836		if (!XFS_FORCED_SHUTDOWN(mp)) {
1837			xfs_notice(mp, "%s: xfs_ifree returned error %d",
1838				__func__, error);
1839			xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1840		}
1841		xfs_trans_cancel(tp);
1842		xfs_iunlock(ip, XFS_ILOCK_EXCL);
1843		return error;
1844	}
1845
1846	/*
1847	 * Credit the quota account(s). The inode is gone.
1848	 */
1849	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_ICOUNT, -1);
1850
1851	/*
1852	 * Just ignore errors at this point.  There is nothing we can do except
1853	 * to try to keep going. Make sure it's not a silent error.
1854	 */
1855	error = xfs_defer_finish(&tp, &dfops, NULL);
1856	if (error) {
1857		xfs_notice(mp, "%s: xfs_defer_finish returned error %d",
1858			__func__, error);
1859		xfs_defer_cancel(&dfops);
1860	}
1861	error = xfs_trans_commit(tp);
1862	if (error)
1863		xfs_notice(mp, "%s: xfs_trans_commit returned error %d",
1864			__func__, error);
1865
1866	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1867	return 0;
1868}
1869
1870/*
1871 * xfs_inactive
1872 *
1873 * This is called when the vnode reference count for the vnode
1874 * goes to zero.  If the file has been unlinked, then it must
1875 * now be truncated.  Also, we clear all of the read-ahead state
1876 * kept for the inode here since the file is now closed.
1877 */
1878void
1879xfs_inactive(
1880	xfs_inode_t	*ip)
1881{
1882	struct xfs_mount	*mp;
1883	int			error;
1884	int			truncate = 0;
1885
1886	/*
1887	 * If the inode is already free, then there can be nothing
1888	 * to clean up here.
1889	 */
1890	if (VFS_I(ip)->i_mode == 0) {
1891		ASSERT(ip->i_df.if_real_bytes == 0);
1892		ASSERT(ip->i_df.if_broot_bytes == 0);
1893		return;
1894	}
1895
1896	mp = ip->i_mount;
1897	ASSERT(!xfs_iflags_test(ip, XFS_IRECOVERY));
1898
1899	/* If this is a read-only mount, don't do this (would generate I/O) */
1900	if (mp->m_flags & XFS_MOUNT_RDONLY)
1901		return;
1902
 
 
 
 
1903	if (VFS_I(ip)->i_nlink != 0) {
1904		/*
1905		 * force is true because we are evicting an inode from the
1906		 * cache. Post-eof blocks must be freed, lest we end up with
1907		 * broken free space accounting.
 
 
 
 
1908		 */
1909		if (xfs_can_free_eofblocks(ip, true)) {
1910			xfs_ilock(ip, XFS_IOLOCK_EXCL);
1911			xfs_free_eofblocks(ip);
1912			xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1913		}
1914
1915		return;
1916	}
1917
1918	if (S_ISREG(VFS_I(ip)->i_mode) &&
1919	    (ip->i_d.di_size != 0 || XFS_ISIZE(ip) != 0 ||
1920	     ip->i_d.di_nextents > 0 || ip->i_delayed_blks > 0))
1921		truncate = 1;
1922
1923	error = xfs_qm_dqattach(ip, 0);
1924	if (error)
1925		return;
1926
1927	if (S_ISLNK(VFS_I(ip)->i_mode))
1928		error = xfs_inactive_symlink(ip);
1929	else if (truncate)
1930		error = xfs_inactive_truncate(ip);
1931	if (error)
1932		return;
1933
1934	/*
1935	 * If there are attributes associated with the file then blow them away
1936	 * now.  The code calls a routine that recursively deconstructs the
1937	 * attribute fork. If also blows away the in-core attribute fork.
1938	 */
1939	if (XFS_IFORK_Q(ip)) {
1940		error = xfs_attr_inactive(ip);
1941		if (error)
1942			return;
1943	}
1944
1945	ASSERT(!ip->i_afp);
1946	ASSERT(ip->i_d.di_anextents == 0);
1947	ASSERT(ip->i_d.di_forkoff == 0);
1948
1949	/*
1950	 * Free the inode.
1951	 */
1952	error = xfs_inactive_ifree(ip);
1953	if (error)
1954		return;
1955
1956	/*
1957	 * Release the dquots held by inode, if any.
1958	 */
1959	xfs_qm_dqdetach(ip);
1960}
1961
1962/*
1963 * This is called when the inode's link count goes to 0 or we are creating a
1964 * tmpfile via O_TMPFILE. In the case of a tmpfile, @ignore_linkcount will be
1965 * set to true as the link count is dropped to zero by the VFS after we've
1966 * created the file successfully, so we have to add it to the unlinked list
1967 * while the link count is non-zero.
1968 *
1969 * We place the on-disk inode on a list in the AGI.  It will be pulled from this
1970 * list when the inode is freed.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1971 */
1972STATIC int
1973xfs_iunlink(
1974	struct xfs_trans *tp,
1975	struct xfs_inode *ip)
 
1976{
1977	xfs_mount_t	*mp = tp->t_mountp;
1978	xfs_agi_t	*agi;
1979	xfs_dinode_t	*dip;
1980	xfs_buf_t	*agibp;
1981	xfs_buf_t	*ibp;
1982	xfs_agino_t	agino;
1983	short		bucket_index;
1984	int		offset;
1985	int		error;
1986
1987	ASSERT(VFS_I(ip)->i_mode != 0);
 
 
 
 
1988
1989	/*
1990	 * Get the agi buffer first.  It ensures lock ordering
1991	 * on the list.
 
 
 
 
1992	 */
1993	error = xfs_read_agi(mp, tp, XFS_INO_TO_AGNO(mp, ip->i_ino), &agibp);
 
1994	if (error)
1995		return error;
1996	agi = XFS_BUF_TO_AGI(agibp);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1997
1998	/*
1999	 * Get the index into the agi hash table for the
2000	 * list this inode will go on.
 
2001	 */
2002	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
2003	ASSERT(agino != 0);
2004	bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
2005	ASSERT(agi->agi_unlinked[bucket_index]);
2006	ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino);
2007
2008	if (agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO)) {
2009		/*
2010		 * There is already another inode in the bucket we need
2011		 * to add ourselves to.  Add us at the front of the list.
2012		 * Here we put the head pointer into our next pointer,
2013		 * and then we fall through to point the head at us.
2014		 */
2015		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2016				       0, 0);
2017		if (error)
2018			return error;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2019
2020		ASSERT(dip->di_next_unlinked == cpu_to_be32(NULLAGINO));
2021		dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
2022		offset = ip->i_imap.im_boffset +
2023			offsetof(xfs_dinode_t, di_next_unlinked);
2024
2025		/* need to recalc the inode CRC if appropriate */
2026		xfs_dinode_calc_crc(mp, dip);
 
2027
2028		xfs_trans_inode_buf(tp, ibp);
2029		xfs_trans_log_buf(tp, ibp, offset,
2030				  (offset + sizeof(xfs_agino_t) - 1));
2031		xfs_inobp_check(mp, ibp);
 
2032	}
2033
2034	/*
2035	 * Point the bucket head pointer at the inode being inserted.
2036	 */
2037	ASSERT(agino != 0);
2038	agi->agi_unlinked[bucket_index] = cpu_to_be32(agino);
2039	offset = offsetof(xfs_agi_t, agi_unlinked) +
2040		(sizeof(xfs_agino_t) * bucket_index);
2041	xfs_trans_log_buf(tp, agibp, offset,
2042			  (offset + sizeof(xfs_agino_t) - 1));
 
 
 
 
 
 
2043	return 0;
 
 
 
2044}
2045
2046/*
2047 * Pull the on-disk inode from the AGI unlinked list.
 
 
 
 
2048 */
2049STATIC int
2050xfs_iunlink_remove(
2051	xfs_trans_t	*tp,
2052	xfs_inode_t	*ip)
2053{
2054	xfs_ino_t	next_ino;
2055	xfs_mount_t	*mp;
2056	xfs_agi_t	*agi;
2057	xfs_dinode_t	*dip;
2058	xfs_buf_t	*agibp;
2059	xfs_buf_t	*ibp;
2060	xfs_agnumber_t	agno;
2061	xfs_agino_t	agino;
2062	xfs_agino_t	next_agino;
2063	xfs_buf_t	*last_ibp;
2064	xfs_dinode_t	*last_dip = NULL;
2065	short		bucket_index;
2066	int		offset, last_offset = 0;
2067	int		error;
2068
2069	mp = tp->t_mountp;
2070	agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
 
2071
2072	/*
2073	 * Get the agi buffer first.  It ensures lock ordering
2074	 * on the list.
2075	 */
2076	error = xfs_read_agi(mp, tp, agno, &agibp);
2077	if (error)
2078		return error;
2079
2080	agi = XFS_BUF_TO_AGI(agibp);
2081
2082	/*
2083	 * Get the index into the agi hash table for the
2084	 * list this inode will go on.
 
2085	 */
2086	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
2087	ASSERT(agino != 0);
2088	bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
2089	ASSERT(agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO));
2090	ASSERT(agi->agi_unlinked[bucket_index]);
2091
2092	if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
2093		/*
2094		 * We're at the head of the list.  Get the inode's on-disk
2095		 * buffer to see if there is anyone after us on the list.
2096		 * Only modify our next pointer if it is not already NULLAGINO.
2097		 * This saves us the overhead of dealing with the buffer when
2098		 * there is no need to change it.
2099		 */
2100		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2101				       0, 0);
2102		if (error) {
2103			xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
2104				__func__, error);
2105			return error;
2106		}
2107		next_agino = be32_to_cpu(dip->di_next_unlinked);
2108		ASSERT(next_agino != 0);
2109		if (next_agino != NULLAGINO) {
2110			dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2111			offset = ip->i_imap.im_boffset +
2112				offsetof(xfs_dinode_t, di_next_unlinked);
2113
2114			/* need to recalc the inode CRC if appropriate */
2115			xfs_dinode_calc_crc(mp, dip);
2116
2117			xfs_trans_inode_buf(tp, ibp);
2118			xfs_trans_log_buf(tp, ibp, offset,
2119					  (offset + sizeof(xfs_agino_t) - 1));
2120			xfs_inobp_check(mp, ibp);
2121		} else {
2122			xfs_trans_brelse(tp, ibp);
2123		}
2124		/*
2125		 * Point the bucket head pointer at the next inode.
 
2126		 */
2127		ASSERT(next_agino != 0);
2128		ASSERT(next_agino != agino);
2129		agi->agi_unlinked[bucket_index] = cpu_to_be32(next_agino);
2130		offset = offsetof(xfs_agi_t, agi_unlinked) +
2131			(sizeof(xfs_agino_t) * bucket_index);
2132		xfs_trans_log_buf(tp, agibp, offset,
2133				  (offset + sizeof(xfs_agino_t) - 1));
2134	} else {
2135		/*
2136		 * We need to search the list for the inode being freed.
 
2137		 */
2138		next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
2139		last_ibp = NULL;
2140		while (next_agino != agino) {
2141			struct xfs_imap	imap;
 
 
2142
2143			if (last_ibp)
2144				xfs_trans_brelse(tp, last_ibp);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2145
2146			imap.im_blkno = 0;
2147			next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2148
2149			error = xfs_imap(mp, tp, next_ino, &imap, 0);
2150			if (error) {
2151				xfs_warn(mp,
2152	"%s: xfs_imap returned error %d.",
2153					 __func__, error);
2154				return error;
2155			}
2156
2157			error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,
2158					       &last_ibp, 0, 0);
2159			if (error) {
2160				xfs_warn(mp,
2161	"%s: xfs_imap_to_bp returned error %d.",
2162					__func__, error);
2163				return error;
2164			}
2165
2166			last_offset = imap.im_boffset;
2167			next_agino = be32_to_cpu(last_dip->di_next_unlinked);
2168			ASSERT(next_agino != NULLAGINO);
2169			ASSERT(next_agino != 0);
2170		}
2171
2172		/*
2173		 * Now last_ibp points to the buffer previous to us on the
2174		 * unlinked list.  Pull us from the list.
2175		 */
2176		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2177				       0, 0);
2178		if (error) {
2179			xfs_warn(mp, "%s: xfs_imap_to_bp(2) returned error %d.",
2180				__func__, error);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2181			return error;
2182		}
2183		next_agino = be32_to_cpu(dip->di_next_unlinked);
2184		ASSERT(next_agino != 0);
2185		ASSERT(next_agino != agino);
2186		if (next_agino != NULLAGINO) {
2187			dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2188			offset = ip->i_imap.im_boffset +
2189				offsetof(xfs_dinode_t, di_next_unlinked);
2190
2191			/* need to recalc the inode CRC if appropriate */
2192			xfs_dinode_calc_crc(mp, dip);
2193
2194			xfs_trans_inode_buf(tp, ibp);
2195			xfs_trans_log_buf(tp, ibp, offset,
2196					  (offset + sizeof(xfs_agino_t) - 1));
2197			xfs_inobp_check(mp, ibp);
2198		} else {
2199			xfs_trans_brelse(tp, ibp);
2200		}
2201		/*
2202		 * Point the previous inode on the list to the next inode.
 
2203		 */
2204		last_dip->di_next_unlinked = cpu_to_be32(next_agino);
2205		ASSERT(next_agino != 0);
2206		offset = last_offset + offsetof(xfs_dinode_t, di_next_unlinked);
 
 
 
 
 
 
 
 
 
 
2207
2208		/* need to recalc the inode CRC if appropriate */
2209		xfs_dinode_calc_crc(mp, last_dip);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2210
2211		xfs_trans_inode_buf(tp, last_ibp);
2212		xfs_trans_log_buf(tp, last_ibp, offset,
2213				  (offset + sizeof(xfs_agino_t) - 1));
2214		xfs_inobp_check(mp, last_ibp);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2215	}
2216	return 0;
 
 
 
 
2217}
2218
2219/*
2220 * A big issue when freeing the inode cluster is that we _cannot_ skip any
2221 * inodes that are in memory - they all must be marked stale and attached to
2222 * the cluster buffer.
2223 */
2224STATIC int
2225xfs_ifree_cluster(
2226	xfs_inode_t		*free_ip,
2227	xfs_trans_t		*tp,
2228	struct xfs_icluster	*xic)
2229{
2230	xfs_mount_t		*mp = free_ip->i_mount;
2231	int			blks_per_cluster;
2232	int			inodes_per_cluster;
2233	int			nbufs;
2234	int			i, j;
2235	int			ioffset;
2236	xfs_daddr_t		blkno;
2237	xfs_buf_t		*bp;
2238	xfs_inode_t		*ip;
2239	xfs_inode_log_item_t	*iip;
2240	xfs_log_item_t		*lip;
2241	struct xfs_perag	*pag;
 
2242	xfs_ino_t		inum;
2243
2244	inum = xic->first_ino;
2245	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, inum));
2246	blks_per_cluster = xfs_icluster_size_fsb(mp);
2247	inodes_per_cluster = blks_per_cluster << mp->m_sb.sb_inopblog;
2248	nbufs = mp->m_ialloc_blks / blks_per_cluster;
2249
2250	for (j = 0; j < nbufs; j++, inum += inodes_per_cluster) {
2251		/*
2252		 * The allocation bitmap tells us which inodes of the chunk were
2253		 * physically allocated. Skip the cluster if an inode falls into
2254		 * a sparse region.
2255		 */
2256		ioffset = inum - xic->first_ino;
2257		if ((xic->alloc & XFS_INOBT_MASK(ioffset)) == 0) {
2258			ASSERT(do_mod(ioffset, inodes_per_cluster) == 0);
2259			continue;
2260		}
2261
2262		blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
2263					 XFS_INO_TO_AGBNO(mp, inum));
2264
2265		/*
2266		 * We obtain and lock the backing buffer first in the process
2267		 * here, as we have to ensure that any dirty inode that we
2268		 * can't get the flush lock on is attached to the buffer.
2269		 * If we scan the in-memory inodes first, then buffer IO can
2270		 * complete before we get a lock on it, and hence we may fail
2271		 * to mark all the active inodes on the buffer stale.
2272		 */
2273		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
2274					mp->m_bsize * blks_per_cluster,
2275					XBF_UNMAPPED);
2276
2277		if (!bp)
2278			return -ENOMEM;
2279
2280		/*
2281		 * This buffer may not have been correctly initialised as we
2282		 * didn't read it from disk. That's not important because we are
2283		 * only using to mark the buffer as stale in the log, and to
2284		 * attach stale cached inodes on it. That means it will never be
2285		 * dispatched for IO. If it is, we want to know about it, and we
2286		 * want it to fail. We can acheive this by adding a write
2287		 * verifier to the buffer.
2288		 */
2289		 bp->b_ops = &xfs_inode_buf_ops;
2290
2291		/*
2292		 * Walk the inodes already attached to the buffer and mark them
2293		 * stale. These will all have the flush locks held, so an
2294		 * in-memory inode walk can't lock them. By marking them all
2295		 * stale first, we will not attempt to lock them in the loop
2296		 * below as the XFS_ISTALE flag will be set.
2297		 */
2298		lip = bp->b_fspriv;
2299		while (lip) {
2300			if (lip->li_type == XFS_LI_INODE) {
2301				iip = (xfs_inode_log_item_t *)lip;
2302				ASSERT(iip->ili_logged == 1);
2303				lip->li_cb = xfs_istale_done;
2304				xfs_trans_ail_copy_lsn(mp->m_ail,
2305							&iip->ili_flush_lsn,
2306							&iip->ili_item.li_lsn);
2307				xfs_iflags_set(iip->ili_inode, XFS_ISTALE);
2308			}
2309			lip = lip->li_bio_list;
2310		}
2311
2312
2313		/*
2314		 * For each inode in memory attempt to add it to the inode
2315		 * buffer and set it up for being staled on buffer IO
2316		 * completion.  This is safe as we've locked out tail pushing
2317		 * and flushing by locking the buffer.
2318		 *
2319		 * We have already marked every inode that was part of a
2320		 * transaction stale above, which means there is no point in
2321		 * even trying to lock them.
2322		 */
2323		for (i = 0; i < inodes_per_cluster; i++) {
2324retry:
2325			rcu_read_lock();
2326			ip = radix_tree_lookup(&pag->pag_ici_root,
2327					XFS_INO_TO_AGINO(mp, (inum + i)));
2328
2329			/* Inode not in memory, nothing to do */
2330			if (!ip) {
2331				rcu_read_unlock();
2332				continue;
2333			}
2334
2335			/*
2336			 * because this is an RCU protected lookup, we could
2337			 * find a recently freed or even reallocated inode
2338			 * during the lookup. We need to check under the
2339			 * i_flags_lock for a valid inode here. Skip it if it
2340			 * is not valid, the wrong inode or stale.
2341			 */
2342			spin_lock(&ip->i_flags_lock);
2343			if (ip->i_ino != inum + i ||
2344			    __xfs_iflags_test(ip, XFS_ISTALE)) {
2345				spin_unlock(&ip->i_flags_lock);
2346				rcu_read_unlock();
2347				continue;
2348			}
2349			spin_unlock(&ip->i_flags_lock);
2350
2351			/*
2352			 * Don't try to lock/unlock the current inode, but we
2353			 * _cannot_ skip the other inodes that we did not find
2354			 * in the list attached to the buffer and are not
2355			 * already marked stale. If we can't lock it, back off
2356			 * and retry.
2357			 */
2358			if (ip != free_ip &&
2359			    !xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
2360				rcu_read_unlock();
2361				delay(1);
2362				goto retry;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2363			}
2364			rcu_read_unlock();
2365
2366			xfs_iflock(ip);
2367			xfs_iflags_set(ip, XFS_ISTALE);
2368
2369			/*
2370			 * we don't need to attach clean inodes or those only
2371			 * with unlogged changes (which we throw away, anyway).
2372			 */
2373			iip = ip->i_itemp;
2374			if (!iip || xfs_inode_clean(ip)) {
2375				ASSERT(ip != free_ip);
2376				xfs_ifunlock(ip);
2377				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2378				continue;
2379			}
2380
2381			iip->ili_last_fields = iip->ili_fields;
2382			iip->ili_fields = 0;
2383			iip->ili_fsync_fields = 0;
2384			iip->ili_logged = 1;
2385			xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
2386						&iip->ili_item.li_lsn);
2387
2388			xfs_buf_attach_iodone(bp, xfs_istale_done,
2389						  &iip->ili_item);
2390
2391			if (ip != free_ip)
2392				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2393		}
2394
2395		xfs_trans_stale_inode_buf(tp, bp);
2396		xfs_trans_binval(tp, bp);
2397	}
2398
2399	xfs_perag_put(pag);
2400	return 0;
2401}
2402
2403/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2404 * This is called to return an inode to the inode free list.
2405 * The inode should already be truncated to 0 length and have
2406 * no pages associated with it.  This routine also assumes that
2407 * the inode is already a part of the transaction.
2408 *
2409 * The on-disk copy of the inode will have been added to the list
2410 * of unlinked inodes in the AGI. We need to remove the inode from
2411 * that list atomically with respect to freeing it here.
2412 */
2413int
2414xfs_ifree(
2415	xfs_trans_t	*tp,
2416	xfs_inode_t	*ip,
2417	struct xfs_defer_ops	*dfops)
2418{
2419	int			error;
2420	struct xfs_icluster	xic = { 0 };
2421
2422	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
2423	ASSERT(VFS_I(ip)->i_nlink == 0);
2424	ASSERT(ip->i_d.di_nextents == 0);
2425	ASSERT(ip->i_d.di_anextents == 0);
2426	ASSERT(ip->i_d.di_size == 0 || !S_ISREG(VFS_I(ip)->i_mode));
2427	ASSERT(ip->i_d.di_nblocks == 0);
2428
2429	/*
2430	 * Pull the on-disk inode from the AGI unlinked list.
2431	 */
2432	error = xfs_iunlink_remove(tp, ip);
2433	if (error)
2434		return error;
2435
2436	error = xfs_difree(tp, ip->i_ino, dfops, &xic);
2437	if (error)
2438		return error;
2439
 
 
 
2440	VFS_I(ip)->i_mode = 0;		/* mark incore inode as free */
2441	ip->i_d.di_flags = 0;
 
2442	ip->i_d.di_dmevmask = 0;
2443	ip->i_d.di_forkoff = 0;		/* mark the attr fork not in use */
2444	ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
2445	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
 
 
 
 
2446	/*
2447	 * Bump the generation count so no one will be confused
2448	 * by reincarnations of this inode.
2449	 */
2450	VFS_I(ip)->i_generation++;
2451	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2452
2453	if (xic.deleted)
2454		error = xfs_ifree_cluster(ip, tp, &xic);
2455
2456	return error;
2457}
2458
2459/*
2460 * This is called to unpin an inode.  The caller must have the inode locked
2461 * in at least shared mode so that the buffer cannot be subsequently pinned
2462 * once someone is waiting for it to be unpinned.
2463 */
2464static void
2465xfs_iunpin(
2466	struct xfs_inode	*ip)
2467{
2468	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
2469
2470	trace_xfs_inode_unpin_nowait(ip, _RET_IP_);
2471
2472	/* Give the log a push to start the unpinning I/O */
2473	xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0);
2474
2475}
2476
2477static void
2478__xfs_iunpin_wait(
2479	struct xfs_inode	*ip)
2480{
2481	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IPINNED_BIT);
2482	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IPINNED_BIT);
2483
2484	xfs_iunpin(ip);
2485
2486	do {
2487		prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
2488		if (xfs_ipincount(ip))
2489			io_schedule();
2490	} while (xfs_ipincount(ip));
2491	finish_wait(wq, &wait.wait);
2492}
2493
2494void
2495xfs_iunpin_wait(
2496	struct xfs_inode	*ip)
2497{
2498	if (xfs_ipincount(ip))
2499		__xfs_iunpin_wait(ip);
2500}
2501
2502/*
2503 * Removing an inode from the namespace involves removing the directory entry
2504 * and dropping the link count on the inode. Removing the directory entry can
2505 * result in locking an AGF (directory blocks were freed) and removing a link
2506 * count can result in placing the inode on an unlinked list which results in
2507 * locking an AGI.
2508 *
2509 * The big problem here is that we have an ordering constraint on AGF and AGI
2510 * locking - inode allocation locks the AGI, then can allocate a new extent for
2511 * new inodes, locking the AGF after the AGI. Similarly, freeing the inode
2512 * removes the inode from the unlinked list, requiring that we lock the AGI
2513 * first, and then freeing the inode can result in an inode chunk being freed
2514 * and hence freeing disk space requiring that we lock an AGF.
2515 *
2516 * Hence the ordering that is imposed by other parts of the code is AGI before
2517 * AGF. This means we cannot remove the directory entry before we drop the inode
2518 * reference count and put it on the unlinked list as this results in a lock
2519 * order of AGF then AGI, and this can deadlock against inode allocation and
2520 * freeing. Therefore we must drop the link counts before we remove the
2521 * directory entry.
2522 *
2523 * This is still safe from a transactional point of view - it is not until we
2524 * get to xfs_defer_finish() that we have the possibility of multiple
2525 * transactions in this operation. Hence as long as we remove the directory
2526 * entry and drop the link count in the first transaction of the remove
2527 * operation, there are no transactional constraints on the ordering here.
2528 */
2529int
2530xfs_remove(
2531	xfs_inode_t             *dp,
2532	struct xfs_name		*name,
2533	xfs_inode_t		*ip)
2534{
2535	xfs_mount_t		*mp = dp->i_mount;
2536	xfs_trans_t             *tp = NULL;
2537	int			is_dir = S_ISDIR(VFS_I(ip)->i_mode);
2538	int                     error = 0;
2539	struct xfs_defer_ops	dfops;
2540	xfs_fsblock_t           first_block;
2541	uint			resblks;
2542
2543	trace_xfs_remove(dp, name);
2544
2545	if (XFS_FORCED_SHUTDOWN(mp))
2546		return -EIO;
2547
2548	error = xfs_qm_dqattach(dp, 0);
2549	if (error)
2550		goto std_return;
2551
2552	error = xfs_qm_dqattach(ip, 0);
2553	if (error)
2554		goto std_return;
2555
2556	/*
2557	 * We try to get the real space reservation first,
2558	 * allowing for directory btree deletion(s) implying
2559	 * possible bmap insert(s).  If we can't get the space
2560	 * reservation then we use 0 instead, and avoid the bmap
2561	 * btree insert(s) in the directory code by, if the bmap
2562	 * insert tries to happen, instead trimming the LAST
2563	 * block from the directory.
2564	 */
2565	resblks = XFS_REMOVE_SPACE_RES(mp);
2566	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, resblks, 0, 0, &tp);
2567	if (error == -ENOSPC) {
2568		resblks = 0;
2569		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, 0, 0, 0,
2570				&tp);
2571	}
2572	if (error) {
2573		ASSERT(error != -ENOSPC);
2574		goto std_return;
2575	}
2576
2577	xfs_lock_two_inodes(dp, ip, XFS_ILOCK_EXCL);
2578
2579	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
2580	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
2581
2582	/*
2583	 * If we're removing a directory perform some additional validation.
2584	 */
2585	if (is_dir) {
2586		ASSERT(VFS_I(ip)->i_nlink >= 2);
2587		if (VFS_I(ip)->i_nlink != 2) {
2588			error = -ENOTEMPTY;
2589			goto out_trans_cancel;
2590		}
2591		if (!xfs_dir_isempty(ip)) {
2592			error = -ENOTEMPTY;
2593			goto out_trans_cancel;
2594		}
2595
2596		/* Drop the link from ip's "..".  */
2597		error = xfs_droplink(tp, dp);
2598		if (error)
2599			goto out_trans_cancel;
2600
2601		/* Drop the "." link from ip to self.  */
2602		error = xfs_droplink(tp, ip);
2603		if (error)
2604			goto out_trans_cancel;
2605	} else {
2606		/*
2607		 * When removing a non-directory we need to log the parent
2608		 * inode here.  For a directory this is done implicitly
2609		 * by the xfs_droplink call for the ".." entry.
2610		 */
2611		xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
2612	}
2613	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2614
2615	/* Drop the link from dp to ip. */
2616	error = xfs_droplink(tp, ip);
2617	if (error)
2618		goto out_trans_cancel;
2619
2620	xfs_defer_init(&dfops, &first_block);
2621	error = xfs_dir_removename(tp, dp, name, ip->i_ino,
2622					&first_block, &dfops, resblks);
2623	if (error) {
2624		ASSERT(error != -ENOENT);
2625		goto out_bmap_cancel;
2626	}
2627
2628	/*
2629	 * If this is a synchronous mount, make sure that the
2630	 * remove transaction goes to disk before returning to
2631	 * the user.
2632	 */
2633	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2634		xfs_trans_set_sync(tp);
2635
2636	error = xfs_defer_finish(&tp, &dfops, NULL);
2637	if (error)
2638		goto out_bmap_cancel;
2639
2640	error = xfs_trans_commit(tp);
2641	if (error)
2642		goto std_return;
2643
2644	if (is_dir && xfs_inode_is_filestream(ip))
2645		xfs_filestream_deassociate(ip);
2646
2647	return 0;
2648
2649 out_bmap_cancel:
2650	xfs_defer_cancel(&dfops);
2651 out_trans_cancel:
2652	xfs_trans_cancel(tp);
2653 std_return:
2654	return error;
2655}
2656
2657/*
2658 * Enter all inodes for a rename transaction into a sorted array.
2659 */
2660#define __XFS_SORT_INODES	5
2661STATIC void
2662xfs_sort_for_rename(
2663	struct xfs_inode	*dp1,	/* in: old (source) directory inode */
2664	struct xfs_inode	*dp2,	/* in: new (target) directory inode */
2665	struct xfs_inode	*ip1,	/* in: inode of old entry */
2666	struct xfs_inode	*ip2,	/* in: inode of new entry */
2667	struct xfs_inode	*wip,	/* in: whiteout inode */
2668	struct xfs_inode	**i_tab,/* out: sorted array of inodes */
2669	int			*num_inodes)  /* in/out: inodes in array */
2670{
2671	int			i, j;
2672
2673	ASSERT(*num_inodes == __XFS_SORT_INODES);
2674	memset(i_tab, 0, *num_inodes * sizeof(struct xfs_inode *));
2675
2676	/*
2677	 * i_tab contains a list of pointers to inodes.  We initialize
2678	 * the table here & we'll sort it.  We will then use it to
2679	 * order the acquisition of the inode locks.
2680	 *
2681	 * Note that the table may contain duplicates.  e.g., dp1 == dp2.
2682	 */
2683	i = 0;
2684	i_tab[i++] = dp1;
2685	i_tab[i++] = dp2;
2686	i_tab[i++] = ip1;
2687	if (ip2)
2688		i_tab[i++] = ip2;
2689	if (wip)
2690		i_tab[i++] = wip;
2691	*num_inodes = i;
2692
2693	/*
2694	 * Sort the elements via bubble sort.  (Remember, there are at
2695	 * most 5 elements to sort, so this is adequate.)
2696	 */
2697	for (i = 0; i < *num_inodes; i++) {
2698		for (j = 1; j < *num_inodes; j++) {
2699			if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
2700				struct xfs_inode *temp = i_tab[j];
2701				i_tab[j] = i_tab[j-1];
2702				i_tab[j-1] = temp;
2703			}
2704		}
2705	}
2706}
2707
2708static int
2709xfs_finish_rename(
2710	struct xfs_trans	*tp,
2711	struct xfs_defer_ops	*dfops)
2712{
2713	int			error;
2714
2715	/*
2716	 * If this is a synchronous mount, make sure that the rename transaction
2717	 * goes to disk before returning to the user.
2718	 */
2719	if (tp->t_mountp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2720		xfs_trans_set_sync(tp);
2721
2722	error = xfs_defer_finish(&tp, dfops, NULL);
2723	if (error) {
2724		xfs_defer_cancel(dfops);
2725		xfs_trans_cancel(tp);
2726		return error;
2727	}
2728
2729	return xfs_trans_commit(tp);
2730}
2731
2732/*
2733 * xfs_cross_rename()
2734 *
2735 * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall
2736 */
2737STATIC int
2738xfs_cross_rename(
2739	struct xfs_trans	*tp,
2740	struct xfs_inode	*dp1,
2741	struct xfs_name		*name1,
2742	struct xfs_inode	*ip1,
2743	struct xfs_inode	*dp2,
2744	struct xfs_name		*name2,
2745	struct xfs_inode	*ip2,
2746	struct xfs_defer_ops	*dfops,
2747	xfs_fsblock_t		*first_block,
2748	int			spaceres)
2749{
2750	int		error = 0;
2751	int		ip1_flags = 0;
2752	int		ip2_flags = 0;
2753	int		dp2_flags = 0;
2754
2755	/* Swap inode number for dirent in first parent */
2756	error = xfs_dir_replace(tp, dp1, name1,
2757				ip2->i_ino,
2758				first_block, dfops, spaceres);
2759	if (error)
2760		goto out_trans_abort;
2761
2762	/* Swap inode number for dirent in second parent */
2763	error = xfs_dir_replace(tp, dp2, name2,
2764				ip1->i_ino,
2765				first_block, dfops, spaceres);
2766	if (error)
2767		goto out_trans_abort;
2768
2769	/*
2770	 * If we're renaming one or more directories across different parents,
2771	 * update the respective ".." entries (and link counts) to match the new
2772	 * parents.
2773	 */
2774	if (dp1 != dp2) {
2775		dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2776
2777		if (S_ISDIR(VFS_I(ip2)->i_mode)) {
2778			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
2779						dp1->i_ino, first_block,
2780						dfops, spaceres);
2781			if (error)
2782				goto out_trans_abort;
2783
2784			/* transfer ip2 ".." reference to dp1 */
2785			if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
2786				error = xfs_droplink(tp, dp2);
2787				if (error)
2788					goto out_trans_abort;
2789				error = xfs_bumplink(tp, dp1);
2790				if (error)
2791					goto out_trans_abort;
2792			}
2793
2794			/*
2795			 * Although ip1 isn't changed here, userspace needs
2796			 * to be warned about the change, so that applications
2797			 * relying on it (like backup ones), will properly
2798			 * notify the change
2799			 */
2800			ip1_flags |= XFS_ICHGTIME_CHG;
2801			ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2802		}
2803
2804		if (S_ISDIR(VFS_I(ip1)->i_mode)) {
2805			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
2806						dp2->i_ino, first_block,
2807						dfops, spaceres);
2808			if (error)
2809				goto out_trans_abort;
2810
2811			/* transfer ip1 ".." reference to dp2 */
2812			if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
2813				error = xfs_droplink(tp, dp1);
2814				if (error)
2815					goto out_trans_abort;
2816				error = xfs_bumplink(tp, dp2);
2817				if (error)
2818					goto out_trans_abort;
2819			}
2820
2821			/*
2822			 * Although ip2 isn't changed here, userspace needs
2823			 * to be warned about the change, so that applications
2824			 * relying on it (like backup ones), will properly
2825			 * notify the change
2826			 */
2827			ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2828			ip2_flags |= XFS_ICHGTIME_CHG;
2829		}
2830	}
2831
2832	if (ip1_flags) {
2833		xfs_trans_ichgtime(tp, ip1, ip1_flags);
2834		xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
2835	}
2836	if (ip2_flags) {
2837		xfs_trans_ichgtime(tp, ip2, ip2_flags);
2838		xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
2839	}
2840	if (dp2_flags) {
2841		xfs_trans_ichgtime(tp, dp2, dp2_flags);
2842		xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
2843	}
2844	xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2845	xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
2846	return xfs_finish_rename(tp, dfops);
2847
2848out_trans_abort:
2849	xfs_defer_cancel(dfops);
2850	xfs_trans_cancel(tp);
2851	return error;
2852}
2853
2854/*
2855 * xfs_rename_alloc_whiteout()
2856 *
2857 * Return a referenced, unlinked, unlocked inode that that can be used as a
2858 * whiteout in a rename transaction. We use a tmpfile inode here so that if we
2859 * crash between allocating the inode and linking it into the rename transaction
2860 * recovery will free the inode and we won't leak it.
2861 */
2862static int
2863xfs_rename_alloc_whiteout(
2864	struct xfs_inode	*dp,
2865	struct xfs_inode	**wip)
2866{
2867	struct xfs_inode	*tmpfile;
2868	int			error;
2869
2870	error = xfs_create_tmpfile(dp, NULL, S_IFCHR | WHITEOUT_MODE, &tmpfile);
2871	if (error)
2872		return error;
2873
2874	/*
2875	 * Prepare the tmpfile inode as if it were created through the VFS.
2876	 * Otherwise, the link increment paths will complain about nlink 0->1.
2877	 * Drop the link count as done by d_tmpfile(), complete the inode setup
2878	 * and flag it as linkable.
2879	 */
2880	drop_nlink(VFS_I(tmpfile));
2881	xfs_setup_iops(tmpfile);
2882	xfs_finish_inode_setup(tmpfile);
2883	VFS_I(tmpfile)->i_state |= I_LINKABLE;
2884
2885	*wip = tmpfile;
2886	return 0;
2887}
2888
2889/*
2890 * xfs_rename
2891 */
2892int
2893xfs_rename(
2894	struct xfs_inode	*src_dp,
2895	struct xfs_name		*src_name,
2896	struct xfs_inode	*src_ip,
2897	struct xfs_inode	*target_dp,
2898	struct xfs_name		*target_name,
2899	struct xfs_inode	*target_ip,
2900	unsigned int		flags)
2901{
2902	struct xfs_mount	*mp = src_dp->i_mount;
2903	struct xfs_trans	*tp;
2904	struct xfs_defer_ops	dfops;
2905	xfs_fsblock_t		first_block;
2906	struct xfs_inode	*wip = NULL;		/* whiteout inode */
2907	struct xfs_inode	*inodes[__XFS_SORT_INODES];
2908	int			num_inodes = __XFS_SORT_INODES;
2909	bool			new_parent = (src_dp != target_dp);
2910	bool			src_is_directory = S_ISDIR(VFS_I(src_ip)->i_mode);
2911	int			spaceres;
2912	int			error;
2913
2914	trace_xfs_rename(src_dp, target_dp, src_name, target_name);
2915
2916	if ((flags & RENAME_EXCHANGE) && !target_ip)
2917		return -EINVAL;
2918
2919	/*
2920	 * If we are doing a whiteout operation, allocate the whiteout inode
2921	 * we will be placing at the target and ensure the type is set
2922	 * appropriately.
2923	 */
2924	if (flags & RENAME_WHITEOUT) {
2925		ASSERT(!(flags & (RENAME_NOREPLACE | RENAME_EXCHANGE)));
2926		error = xfs_rename_alloc_whiteout(target_dp, &wip);
2927		if (error)
2928			return error;
2929
2930		/* setup target dirent info as whiteout */
2931		src_name->type = XFS_DIR3_FT_CHRDEV;
2932	}
2933
2934	xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip, wip,
2935				inodes, &num_inodes);
2936
2937	spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
2938	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, spaceres, 0, 0, &tp);
2939	if (error == -ENOSPC) {
2940		spaceres = 0;
2941		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, 0, 0, 0,
2942				&tp);
2943	}
2944	if (error)
2945		goto out_release_wip;
2946
2947	/*
2948	 * Attach the dquots to the inodes
2949	 */
2950	error = xfs_qm_vop_rename_dqattach(inodes);
2951	if (error)
2952		goto out_trans_cancel;
2953
2954	/*
2955	 * Lock all the participating inodes. Depending upon whether
2956	 * the target_name exists in the target directory, and
2957	 * whether the target directory is the same as the source
2958	 * directory, we can lock from 2 to 4 inodes.
2959	 */
2960	xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
2961
2962	/*
2963	 * Join all the inodes to the transaction. From this point on,
2964	 * we can rely on either trans_commit or trans_cancel to unlock
2965	 * them.
2966	 */
2967	xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
2968	if (new_parent)
2969		xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
2970	xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
2971	if (target_ip)
2972		xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
2973	if (wip)
2974		xfs_trans_ijoin(tp, wip, XFS_ILOCK_EXCL);
2975
2976	/*
2977	 * If we are using project inheritance, we only allow renames
2978	 * into our tree when the project IDs are the same; else the
2979	 * tree quota mechanism would be circumvented.
2980	 */
2981	if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
2982		     (xfs_get_projid(target_dp) != xfs_get_projid(src_ip)))) {
2983		error = -EXDEV;
2984		goto out_trans_cancel;
2985	}
2986
2987	xfs_defer_init(&dfops, &first_block);
2988
2989	/* RENAME_EXCHANGE is unique from here on. */
2990	if (flags & RENAME_EXCHANGE)
2991		return xfs_cross_rename(tp, src_dp, src_name, src_ip,
2992					target_dp, target_name, target_ip,
2993					&dfops, &first_block, spaceres);
2994
2995	/*
2996	 * Set up the target.
 
2997	 */
2998	if (target_ip == NULL) {
2999		/*
3000		 * If there's no space reservation, check the entry will
3001		 * fit before actually inserting it.
3002		 */
3003		if (!spaceres) {
3004			error = xfs_dir_canenter(tp, target_dp, target_name);
3005			if (error)
3006				goto out_trans_cancel;
3007		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3008		/*
3009		 * If target does not exist and the rename crosses
3010		 * directories, adjust the target directory link count
3011		 * to account for the ".." reference from the new entry.
3012		 */
3013		error = xfs_dir_createname(tp, target_dp, target_name,
3014						src_ip->i_ino, &first_block,
3015						&dfops, spaceres);
3016		if (error)
3017			goto out_bmap_cancel;
3018
3019		xfs_trans_ichgtime(tp, target_dp,
3020					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3021
3022		if (new_parent && src_is_directory) {
3023			error = xfs_bumplink(tp, target_dp);
3024			if (error)
3025				goto out_bmap_cancel;
3026		}
3027	} else { /* target_ip != NULL */
3028		/*
3029		 * If target exists and it's a directory, check that both
3030		 * target and source are directories and that target can be
3031		 * destroyed, or that neither is a directory.
3032		 */
3033		if (S_ISDIR(VFS_I(target_ip)->i_mode)) {
3034			/*
3035			 * Make sure target dir is empty.
3036			 */
3037			if (!(xfs_dir_isempty(target_ip)) ||
3038			    (VFS_I(target_ip)->i_nlink > 2)) {
3039				error = -EEXIST;
3040				goto out_trans_cancel;
3041			}
3042		}
3043
3044		/*
3045		 * Link the source inode under the target name.
3046		 * If the source inode is a directory and we are moving
3047		 * it across directories, its ".." entry will be
3048		 * inconsistent until we replace that down below.
3049		 *
3050		 * In case there is already an entry with the same
3051		 * name at the destination directory, remove it first.
3052		 */
3053		error = xfs_dir_replace(tp, target_dp, target_name,
3054					src_ip->i_ino,
3055					&first_block, &dfops, spaceres);
3056		if (error)
3057			goto out_bmap_cancel;
3058
3059		xfs_trans_ichgtime(tp, target_dp,
3060					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3061
3062		/*
3063		 * Decrement the link count on the target since the target
3064		 * dir no longer points to it.
3065		 */
3066		error = xfs_droplink(tp, target_ip);
3067		if (error)
3068			goto out_bmap_cancel;
3069
3070		if (src_is_directory) {
3071			/*
3072			 * Drop the link from the old "." entry.
3073			 */
3074			error = xfs_droplink(tp, target_ip);
3075			if (error)
3076				goto out_bmap_cancel;
3077		}
3078	} /* target_ip != NULL */
3079
3080	/*
3081	 * Remove the source.
3082	 */
3083	if (new_parent && src_is_directory) {
3084		/*
3085		 * Rewrite the ".." entry to point to the new
3086		 * directory.
3087		 */
3088		error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
3089					target_dp->i_ino,
3090					&first_block, &dfops, spaceres);
3091		ASSERT(error != -EEXIST);
3092		if (error)
3093			goto out_bmap_cancel;
3094	}
3095
3096	/*
3097	 * We always want to hit the ctime on the source inode.
3098	 *
3099	 * This isn't strictly required by the standards since the source
3100	 * inode isn't really being changed, but old unix file systems did
3101	 * it and some incremental backup programs won't work without it.
3102	 */
3103	xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
3104	xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
3105
3106	/*
3107	 * Adjust the link count on src_dp.  This is necessary when
3108	 * renaming a directory, either within one parent when
3109	 * the target existed, or across two parent directories.
3110	 */
3111	if (src_is_directory && (new_parent || target_ip != NULL)) {
3112
3113		/*
3114		 * Decrement link count on src_directory since the
3115		 * entry that's moved no longer points to it.
3116		 */
3117		error = xfs_droplink(tp, src_dp);
3118		if (error)
3119			goto out_bmap_cancel;
3120	}
3121
3122	/*
3123	 * For whiteouts, we only need to update the source dirent with the
3124	 * inode number of the whiteout inode rather than removing it
3125	 * altogether.
3126	 */
3127	if (wip) {
3128		error = xfs_dir_replace(tp, src_dp, src_name, wip->i_ino,
3129					&first_block, &dfops, spaceres);
3130	} else
3131		error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
3132					   &first_block, &dfops, spaceres);
3133	if (error)
3134		goto out_bmap_cancel;
3135
3136	/*
3137	 * For whiteouts, we need to bump the link count on the whiteout inode.
3138	 * This means that failures all the way up to this point leave the inode
3139	 * on the unlinked list and so cleanup is a simple matter of dropping
3140	 * the remaining reference to it. If we fail here after bumping the link
3141	 * count, we're shutting down the filesystem so we'll never see the
3142	 * intermediate state on disk.
3143	 */
3144	if (wip) {
3145		ASSERT(VFS_I(wip)->i_nlink == 0);
3146		error = xfs_bumplink(tp, wip);
3147		if (error)
3148			goto out_bmap_cancel;
3149		error = xfs_iunlink_remove(tp, wip);
3150		if (error)
3151			goto out_bmap_cancel;
3152		xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE);
3153
3154		/*
3155		 * Now we have a real link, clear the "I'm a tmpfile" state
3156		 * flag from the inode so it doesn't accidentally get misused in
3157		 * future.
3158		 */
3159		VFS_I(wip)->i_state &= ~I_LINKABLE;
3160	}
3161
3162	xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3163	xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
3164	if (new_parent)
3165		xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
3166
3167	error = xfs_finish_rename(tp, &dfops);
3168	if (wip)
3169		IRELE(wip);
3170	return error;
3171
3172out_bmap_cancel:
3173	xfs_defer_cancel(&dfops);
3174out_trans_cancel:
3175	xfs_trans_cancel(tp);
3176out_release_wip:
3177	if (wip)
3178		IRELE(wip);
3179	return error;
3180}
3181
3182STATIC int
3183xfs_iflush_cluster(
3184	struct xfs_inode	*ip,
3185	struct xfs_buf		*bp)
3186{
3187	struct xfs_mount	*mp = ip->i_mount;
3188	struct xfs_perag	*pag;
3189	unsigned long		first_index, mask;
3190	unsigned long		inodes_per_cluster;
3191	int			cilist_size;
3192	struct xfs_inode	**cilist;
3193	struct xfs_inode	*cip;
 
3194	int			nr_found;
3195	int			clcount = 0;
3196	int			bufwasdelwri;
3197	int			i;
3198
3199	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
3200
3201	inodes_per_cluster = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;
3202	cilist_size = inodes_per_cluster * sizeof(xfs_inode_t *);
3203	cilist = kmem_alloc(cilist_size, KM_MAYFAIL|KM_NOFS);
3204	if (!cilist)
3205		goto out_put;
3206
3207	mask = ~(((mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog)) - 1);
3208	first_index = XFS_INO_TO_AGINO(mp, ip->i_ino) & mask;
3209	rcu_read_lock();
3210	/* really need a gang lookup range call here */
3211	nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void**)cilist,
3212					first_index, inodes_per_cluster);
3213	if (nr_found == 0)
3214		goto out_free;
3215
3216	for (i = 0; i < nr_found; i++) {
3217		cip = cilist[i];
3218		if (cip == ip)
3219			continue;
3220
3221		/*
3222		 * because this is an RCU protected lookup, we could find a
3223		 * recently freed or even reallocated inode during the lookup.
3224		 * We need to check under the i_flags_lock for a valid inode
3225		 * here. Skip it if it is not valid or the wrong inode.
3226		 */
3227		spin_lock(&cip->i_flags_lock);
3228		if (!cip->i_ino ||
3229		    __xfs_iflags_test(cip, XFS_ISTALE)) {
3230			spin_unlock(&cip->i_flags_lock);
3231			continue;
3232		}
3233
3234		/*
3235		 * Once we fall off the end of the cluster, no point checking
3236		 * any more inodes in the list because they will also all be
3237		 * outside the cluster.
3238		 */
3239		if ((XFS_INO_TO_AGINO(mp, cip->i_ino) & mask) != first_index) {
3240			spin_unlock(&cip->i_flags_lock);
3241			break;
3242		}
3243		spin_unlock(&cip->i_flags_lock);
3244
3245		/*
3246		 * Do an un-protected check to see if the inode is dirty and
3247		 * is a candidate for flushing.  These checks will be repeated
3248		 * later after the appropriate locks are acquired.
3249		 */
3250		if (xfs_inode_clean(cip) && xfs_ipincount(cip) == 0)
3251			continue;
3252
3253		/*
3254		 * Try to get locks.  If any are unavailable or it is pinned,
3255		 * then this inode cannot be flushed and is skipped.
3256		 */
3257
3258		if (!xfs_ilock_nowait(cip, XFS_ILOCK_SHARED))
3259			continue;
3260		if (!xfs_iflock_nowait(cip)) {
3261			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3262			continue;
3263		}
3264		if (xfs_ipincount(cip)) {
3265			xfs_ifunlock(cip);
3266			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3267			continue;
3268		}
3269
3270
3271		/*
3272		 * Check the inode number again, just to be certain we are not
3273		 * racing with freeing in xfs_reclaim_inode(). See the comments
3274		 * in that function for more information as to why the initial
3275		 * check is not sufficient.
3276		 */
3277		if (!cip->i_ino) {
3278			xfs_ifunlock(cip);
3279			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3280			continue;
3281		}
3282
3283		/*
3284		 * arriving here means that this inode can be flushed.  First
3285		 * re-check that it's dirty before flushing.
3286		 */
3287		if (!xfs_inode_clean(cip)) {
3288			int	error;
3289			error = xfs_iflush_int(cip, bp);
3290			if (error) {
3291				xfs_iunlock(cip, XFS_ILOCK_SHARED);
3292				goto cluster_corrupt_out;
3293			}
3294			clcount++;
3295		} else {
3296			xfs_ifunlock(cip);
3297		}
3298		xfs_iunlock(cip, XFS_ILOCK_SHARED);
3299	}
3300
3301	if (clcount) {
3302		XFS_STATS_INC(mp, xs_icluster_flushcnt);
3303		XFS_STATS_ADD(mp, xs_icluster_flushinode, clcount);
3304	}
3305
3306out_free:
3307	rcu_read_unlock();
3308	kmem_free(cilist);
3309out_put:
3310	xfs_perag_put(pag);
3311	return 0;
3312
3313
3314cluster_corrupt_out:
3315	/*
3316	 * Corruption detected in the clustering loop.  Invalidate the
3317	 * inode buffer and shut down the filesystem.
3318	 */
3319	rcu_read_unlock();
 
3320	/*
3321	 * Clean up the buffer.  If it was delwri, just release it --
3322	 * brelse can handle it with no problems.  If not, shut down the
3323	 * filesystem before releasing the buffer.
3324	 */
3325	bufwasdelwri = (bp->b_flags & _XBF_DELWRI_Q);
3326	if (bufwasdelwri)
3327		xfs_buf_relse(bp);
 
 
 
 
 
3328
3329	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3330
3331	if (!bufwasdelwri) {
3332		/*
3333		 * Just like incore_relse: if we have b_iodone functions,
3334		 * mark the buffer as an error and call them.  Otherwise
3335		 * mark it as stale and brelse.
3336		 */
3337		if (bp->b_iodone) {
3338			bp->b_flags &= ~XBF_DONE;
3339			xfs_buf_stale(bp);
3340			xfs_buf_ioerror(bp, -EIO);
3341			xfs_buf_ioend(bp);
3342		} else {
3343			xfs_buf_stale(bp);
3344			xfs_buf_relse(bp);
3345		}
3346	}
3347
3348	/*
3349	 * Unlocks the flush lock
3350	 */
3351	xfs_iflush_abort(cip, false);
3352	kmem_free(cilist);
3353	xfs_perag_put(pag);
3354	return -EFSCORRUPTED;
3355}
3356
3357/*
3358 * Flush dirty inode metadata into the backing buffer.
3359 *
3360 * The caller must have the inode lock and the inode flush lock held.  The
3361 * inode lock will still be held upon return to the caller, and the inode
3362 * flush lock will be released after the inode has reached the disk.
3363 *
3364 * The caller must write out the buffer returned in *bpp and release it.
3365 */
3366int
3367xfs_iflush(
3368	struct xfs_inode	*ip,
3369	struct xfs_buf		**bpp)
3370{
3371	struct xfs_mount	*mp = ip->i_mount;
3372	struct xfs_buf		*bp = NULL;
3373	struct xfs_dinode	*dip;
3374	int			error;
3375
3376	XFS_STATS_INC(mp, xs_iflush_count);
3377
3378	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3379	ASSERT(xfs_isiflocked(ip));
3380	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3381	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3382
3383	*bpp = NULL;
3384
3385	xfs_iunpin_wait(ip);
3386
3387	/*
3388	 * For stale inodes we cannot rely on the backing buffer remaining
3389	 * stale in cache for the remaining life of the stale inode and so
3390	 * xfs_imap_to_bp() below may give us a buffer that no longer contains
3391	 * inodes below. We have to check this after ensuring the inode is
3392	 * unpinned so that it is safe to reclaim the stale inode after the
3393	 * flush call.
3394	 */
3395	if (xfs_iflags_test(ip, XFS_ISTALE)) {
3396		xfs_ifunlock(ip);
3397		return 0;
3398	}
3399
3400	/*
3401	 * This may have been unpinned because the filesystem is shutting
3402	 * down forcibly. If that's the case we must not write this inode
3403	 * to disk, because the log record didn't make it to disk.
3404	 *
3405	 * We also have to remove the log item from the AIL in this case,
3406	 * as we wait for an empty AIL as part of the unmount process.
3407	 */
3408	if (XFS_FORCED_SHUTDOWN(mp)) {
3409		error = -EIO;
3410		goto abort_out;
3411	}
3412
3413	/*
3414	 * Get the buffer containing the on-disk inode. We are doing a try-lock
3415	 * operation here, so we may get  an EAGAIN error. In that case, we
3416	 * simply want to return with the inode still dirty.
3417	 *
3418	 * If we get any other error, we effectively have a corruption situation
3419	 * and we cannot flush the inode, so we treat it the same as failing
3420	 * xfs_iflush_int().
3421	 */
3422	error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, XBF_TRYLOCK,
3423			       0);
3424	if (error == -EAGAIN) {
3425		xfs_ifunlock(ip);
3426		return error;
3427	}
3428	if (error)
3429		goto corrupt_out;
3430
3431	/*
3432	 * First flush out the inode that xfs_iflush was called with.
3433	 */
3434	error = xfs_iflush_int(ip, bp);
3435	if (error)
3436		goto corrupt_out;
3437
3438	/*
3439	 * If the buffer is pinned then push on the log now so we won't
3440	 * get stuck waiting in the write for too long.
3441	 */
3442	if (xfs_buf_ispinned(bp))
3443		xfs_log_force(mp, 0);
3444
3445	/*
3446	 * inode clustering:
3447	 * see if other inodes can be gathered into this write
 
 
 
 
 
3448	 */
3449	error = xfs_iflush_cluster(ip, bp);
3450	if (error)
3451		goto cluster_corrupt_out;
3452
3453	*bpp = bp;
3454	return 0;
3455
3456corrupt_out:
3457	if (bp)
3458		xfs_buf_relse(bp);
3459	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3460cluster_corrupt_out:
3461	error = -EFSCORRUPTED;
3462abort_out:
3463	/*
3464	 * Unlocks the flush lock
3465	 */
3466	xfs_iflush_abort(ip, false);
3467	return error;
3468}
3469
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3470STATIC int
3471xfs_iflush_int(
3472	struct xfs_inode	*ip,
3473	struct xfs_buf		*bp)
3474{
3475	struct xfs_inode_log_item *iip = ip->i_itemp;
3476	struct xfs_dinode	*dip;
3477	struct xfs_mount	*mp = ip->i_mount;
3478
3479	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3480	ASSERT(xfs_isiflocked(ip));
3481	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3482	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3483	ASSERT(iip != NULL && iip->ili_fields != 0);
3484	ASSERT(ip->i_d.di_version > 1);
3485
3486	/* set *dip = inode's place in the buffer */
3487	dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);
3488
3489	if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
3490			       mp, XFS_ERRTAG_IFLUSH_1, XFS_RANDOM_IFLUSH_1)) {
3491		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3492			"%s: Bad inode %Lu magic number 0x%x, ptr 0x%p",
3493			__func__, ip->i_ino, be16_to_cpu(dip->di_magic), dip);
3494		goto corrupt_out;
3495	}
3496	if (S_ISREG(VFS_I(ip)->i_mode)) {
3497		if (XFS_TEST_ERROR(
3498		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3499		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
3500		    mp, XFS_ERRTAG_IFLUSH_3, XFS_RANDOM_IFLUSH_3)) {
3501			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3502				"%s: Bad regular inode %Lu, ptr 0x%p",
3503				__func__, ip->i_ino, ip);
3504			goto corrupt_out;
3505		}
3506	} else if (S_ISDIR(VFS_I(ip)->i_mode)) {
3507		if (XFS_TEST_ERROR(
3508		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3509		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
3510		    (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
3511		    mp, XFS_ERRTAG_IFLUSH_4, XFS_RANDOM_IFLUSH_4)) {
3512			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3513				"%s: Bad directory inode %Lu, ptr 0x%p",
3514				__func__, ip->i_ino, ip);
3515			goto corrupt_out;
3516		}
3517	}
3518	if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
3519				ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5,
3520				XFS_RANDOM_IFLUSH_5)) {
3521		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3522			"%s: detected corrupt incore inode %Lu, "
3523			"total extents = %d, nblocks = %Ld, ptr 0x%p",
3524			__func__, ip->i_ino,
3525			ip->i_d.di_nextents + ip->i_d.di_anextents,
3526			ip->i_d.di_nblocks, ip);
3527		goto corrupt_out;
3528	}
3529	if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
3530				mp, XFS_ERRTAG_IFLUSH_6, XFS_RANDOM_IFLUSH_6)) {
3531		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3532			"%s: bad inode %Lu, forkoff 0x%x, ptr 0x%p",
3533			__func__, ip->i_ino, ip->i_d.di_forkoff, ip);
3534		goto corrupt_out;
3535	}
3536
3537	/*
3538	 * Inode item log recovery for v2 inodes are dependent on the
3539	 * di_flushiter count for correct sequencing. We bump the flush
3540	 * iteration count so we can detect flushes which postdate a log record
3541	 * during recovery. This is redundant as we now log every change and
3542	 * hence this can't happen but we need to still do it to ensure
3543	 * backwards compatibility with old kernels that predate logging all
3544	 * inode changes.
3545	 */
3546	if (ip->i_d.di_version < 3)
3547		ip->i_d.di_flushiter++;
3548
 
 
 
 
3549	/*
3550	 * Copy the dirty parts of the inode into the on-disk inode.  We always
3551	 * copy out the core of the inode, because if the inode is dirty at all
3552	 * the core must be.
3553	 */
3554	xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);
3555
3556	/* Wrap, we never let the log put out DI_MAX_FLUSH */
3557	if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
3558		ip->i_d.di_flushiter = 0;
3559
3560	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
3561	if (XFS_IFORK_Q(ip))
3562		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
3563	xfs_inobp_check(mp, bp);
3564
3565	/*
3566	 * We've recorded everything logged in the inode, so we'd like to clear
3567	 * the ili_fields bits so we don't log and flush things unnecessarily.
3568	 * However, we can't stop logging all this information until the data
3569	 * we've copied into the disk buffer is written to disk.  If we did we
3570	 * might overwrite the copy of the inode in the log with all the data
3571	 * after re-logging only part of it, and in the face of a crash we
3572	 * wouldn't have all the data we need to recover.
3573	 *
3574	 * What we do is move the bits to the ili_last_fields field.  When
3575	 * logging the inode, these bits are moved back to the ili_fields field.
3576	 * In the xfs_iflush_done() routine we clear ili_last_fields, since we
3577	 * know that the information those bits represent is permanently on
3578	 * disk.  As long as the flush completes before the inode is logged
3579	 * again, then both ili_fields and ili_last_fields will be cleared.
3580	 *
3581	 * We can play with the ili_fields bits here, because the inode lock
3582	 * must be held exclusively in order to set bits there and the flush
3583	 * lock protects the ili_last_fields bits.  Set ili_logged so the flush
3584	 * done routine can tell whether or not to look in the AIL.  Also, store
3585	 * the current LSN of the inode so that we can tell whether the item has
3586	 * moved in the AIL from xfs_iflush_done().  In order to read the lsn we
3587	 * need the AIL lock, because it is a 64 bit value that cannot be read
3588	 * atomically.
3589	 */
3590	iip->ili_last_fields = iip->ili_fields;
3591	iip->ili_fields = 0;
3592	iip->ili_fsync_fields = 0;
3593	iip->ili_logged = 1;
3594
3595	xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
3596				&iip->ili_item.li_lsn);
3597
3598	/*
3599	 * Attach the function xfs_iflush_done to the inode's
3600	 * buffer.  This will remove the inode from the AIL
3601	 * and unlock the inode's flush lock when the inode is
3602	 * completely written to disk.
3603	 */
3604	xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);
3605
3606	/* generate the checksum. */
3607	xfs_dinode_calc_crc(mp, dip);
3608
3609	ASSERT(bp->b_fspriv != NULL);
3610	ASSERT(bp->b_iodone != NULL);
3611	return 0;
3612
3613corrupt_out:
3614	return -EFSCORRUPTED;
 
 
 
 
 
 
 
 
 
3615}