Linux Audio

Check our new training course

Yocto / OpenEmbedded training

Feb 10-13, 2025
Register
Loading...
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}
v4.6
 
   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_inode.h"
  29#include "xfs_da_format.h"
  30#include "xfs_da_btree.h"
  31#include "xfs_dir2.h"
  32#include "xfs_attr_sf.h"
  33#include "xfs_attr.h"
  34#include "xfs_trans_space.h"
  35#include "xfs_trans.h"
  36#include "xfs_buf_item.h"
  37#include "xfs_inode_item.h"
  38#include "xfs_ialloc.h"
  39#include "xfs_bmap.h"
  40#include "xfs_bmap_util.h"
 
  41#include "xfs_error.h"
  42#include "xfs_quota.h"
  43#include "xfs_filestream.h"
  44#include "xfs_cksum.h"
  45#include "xfs_trace.h"
  46#include "xfs_icache.h"
  47#include "xfs_symlink.h"
  48#include "xfs_trans_priv.h"
  49#include "xfs_log.h"
  50#include "xfs_bmap_btree.h"
 
  51
  52kmem_zone_t *xfs_inode_zone;
  53
  54/*
  55 * Used in xfs_itruncate_extents().  This is the maximum number of extents
  56 * freed from a file in a single transaction.
  57 */
  58#define	XFS_ITRUNC_MAX_EXTENTS	2
  59
  60STATIC int xfs_iflush_int(struct xfs_inode *, struct xfs_buf *);
  61STATIC int xfs_iunlink(struct xfs_trans *, struct xfs_inode *);
  62STATIC int xfs_iunlink_remove(struct xfs_trans *, struct xfs_inode *);
  63
  64/*
  65 * helper function to extract extent size hint from inode
  66 */
  67xfs_extlen_t
  68xfs_get_extsz_hint(
  69	struct xfs_inode	*ip)
  70{
  71	if ((ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE) && ip->i_d.di_extsize)
  72		return ip->i_d.di_extsize;
  73	if (XFS_IS_REALTIME_INODE(ip))
  74		return ip->i_mount->m_sb.sb_rextsize;
  75	return 0;
  76}
  77
  78/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  79 * These two are wrapper routines around the xfs_ilock() routine used to
  80 * centralize some grungy code.  They are used in places that wish to lock the
  81 * inode solely for reading the extents.  The reason these places can't just
  82 * call xfs_ilock(ip, XFS_ILOCK_SHARED) is that the inode lock also guards to
  83 * bringing in of the extents from disk for a file in b-tree format.  If the
  84 * inode is in b-tree format, then we need to lock the inode exclusively until
  85 * the extents are read in.  Locking it exclusively all the time would limit
  86 * our parallelism unnecessarily, though.  What we do instead is check to see
  87 * if the extents have been read in yet, and only lock the inode exclusively
  88 * if they have not.
  89 *
  90 * The functions return a value which should be given to the corresponding
  91 * xfs_iunlock() call.
  92 */
  93uint
  94xfs_ilock_data_map_shared(
  95	struct xfs_inode	*ip)
  96{
  97	uint			lock_mode = XFS_ILOCK_SHARED;
  98
  99	if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
 100	    (ip->i_df.if_flags & XFS_IFEXTENTS) == 0)
 101		lock_mode = XFS_ILOCK_EXCL;
 102	xfs_ilock(ip, lock_mode);
 103	return lock_mode;
 104}
 105
 106uint
 107xfs_ilock_attr_map_shared(
 108	struct xfs_inode	*ip)
 109{
 110	uint			lock_mode = XFS_ILOCK_SHARED;
 111
 112	if (ip->i_d.di_aformat == XFS_DINODE_FMT_BTREE &&
 113	    (ip->i_afp->if_flags & XFS_IFEXTENTS) == 0)
 114		lock_mode = XFS_ILOCK_EXCL;
 115	xfs_ilock(ip, lock_mode);
 116	return lock_mode;
 117}
 118
 119/*
 120 * The xfs inode contains 3 multi-reader locks: the i_iolock the i_mmap_lock and
 121 * the i_lock.  This routine allows various combinations of the locks to be
 122 * obtained.
 123 *
 124 * The 3 locks should always be ordered so that the IO lock is obtained first,
 125 * the mmap lock second and the ilock last in order to prevent deadlock.
 126 *
 127 * Basic locking order:
 128 *
 129 * i_iolock -> i_mmap_lock -> page_lock -> i_ilock
 130 *
 131 * mmap_sem locking order:
 132 *
 133 * i_iolock -> page lock -> mmap_sem
 134 * mmap_sem -> i_mmap_lock -> page_lock
 135 *
 136 * The difference in mmap_sem locking order mean that we cannot hold the
 137 * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can
 138 * fault in pages during copy in/out (for buffered IO) or require the mmap_sem
 139 * in get_user_pages() to map the user pages into the kernel address space for
 140 * direct IO. Similarly the i_iolock cannot be taken inside a page fault because
 141 * page faults already hold the mmap_sem.
 142 *
 143 * Hence to serialise fully against both syscall and mmap based IO, we need to
 144 * take both the i_iolock and the i_mmap_lock. These locks should *only* be both
 145 * taken in places where we need to invalidate the page cache in a race
 146 * free manner (e.g. truncate, hole punch and other extent manipulation
 147 * functions).
 148 */
 149void
 150xfs_ilock(
 151	xfs_inode_t		*ip,
 152	uint			lock_flags)
 153{
 154	trace_xfs_ilock(ip, lock_flags, _RET_IP_);
 155
 156	/*
 157	 * You can't set both SHARED and EXCL for the same lock,
 158	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 159	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 160	 */
 161	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 162	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 163	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 164	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 165	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 166	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 167	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 168
 169	if (lock_flags & XFS_IOLOCK_EXCL)
 170		mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
 171	else if (lock_flags & XFS_IOLOCK_SHARED)
 172		mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
 
 
 
 173
 174	if (lock_flags & XFS_MMAPLOCK_EXCL)
 175		mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
 176	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 177		mraccess_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
 178
 179	if (lock_flags & XFS_ILOCK_EXCL)
 180		mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
 181	else if (lock_flags & XFS_ILOCK_SHARED)
 182		mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
 183}
 184
 185/*
 186 * This is just like xfs_ilock(), except that the caller
 187 * is guaranteed not to sleep.  It returns 1 if it gets
 188 * the requested locks and 0 otherwise.  If the IO lock is
 189 * obtained but the inode lock cannot be, then the IO lock
 190 * is dropped before returning.
 191 *
 192 * ip -- the inode being locked
 193 * lock_flags -- this parameter indicates the inode's locks to be
 194 *       to be locked.  See the comment for xfs_ilock() for a list
 195 *	 of valid values.
 196 */
 197int
 198xfs_ilock_nowait(
 199	xfs_inode_t		*ip,
 200	uint			lock_flags)
 201{
 202	trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
 203
 204	/*
 205	 * You can't set both SHARED and EXCL for the same lock,
 206	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 207	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 208	 */
 209	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 210	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 211	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 212	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 213	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 214	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 215	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 216
 217	if (lock_flags & XFS_IOLOCK_EXCL) {
 218		if (!mrtryupdate(&ip->i_iolock))
 219			goto out;
 220	} else if (lock_flags & XFS_IOLOCK_SHARED) {
 221		if (!mrtryaccess(&ip->i_iolock))
 222			goto out;
 223	}
 224
 225	if (lock_flags & XFS_MMAPLOCK_EXCL) {
 226		if (!mrtryupdate(&ip->i_mmaplock))
 227			goto out_undo_iolock;
 228	} else if (lock_flags & XFS_MMAPLOCK_SHARED) {
 229		if (!mrtryaccess(&ip->i_mmaplock))
 230			goto out_undo_iolock;
 231	}
 232
 233	if (lock_flags & XFS_ILOCK_EXCL) {
 234		if (!mrtryupdate(&ip->i_lock))
 235			goto out_undo_mmaplock;
 236	} else if (lock_flags & XFS_ILOCK_SHARED) {
 237		if (!mrtryaccess(&ip->i_lock))
 238			goto out_undo_mmaplock;
 239	}
 240	return 1;
 241
 242out_undo_mmaplock:
 243	if (lock_flags & XFS_MMAPLOCK_EXCL)
 244		mrunlock_excl(&ip->i_mmaplock);
 245	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 246		mrunlock_shared(&ip->i_mmaplock);
 247out_undo_iolock:
 248	if (lock_flags & XFS_IOLOCK_EXCL)
 249		mrunlock_excl(&ip->i_iolock);
 250	else if (lock_flags & XFS_IOLOCK_SHARED)
 251		mrunlock_shared(&ip->i_iolock);
 252out:
 253	return 0;
 254}
 255
 256/*
 257 * xfs_iunlock() is used to drop the inode locks acquired with
 258 * xfs_ilock() and xfs_ilock_nowait().  The caller must pass
 259 * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
 260 * that we know which locks to drop.
 261 *
 262 * ip -- the inode being unlocked
 263 * lock_flags -- this parameter indicates the inode's locks to be
 264 *       to be unlocked.  See the comment for xfs_ilock() for a list
 265 *	 of valid values for this parameter.
 266 *
 267 */
 268void
 269xfs_iunlock(
 270	xfs_inode_t		*ip,
 271	uint			lock_flags)
 272{
 273	/*
 274	 * You can't set both SHARED and EXCL for the same lock,
 275	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
 276	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
 277	 */
 278	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
 279	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
 280	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
 281	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
 282	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
 283	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
 284	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
 285	ASSERT(lock_flags != 0);
 286
 287	if (lock_flags & XFS_IOLOCK_EXCL)
 288		mrunlock_excl(&ip->i_iolock);
 289	else if (lock_flags & XFS_IOLOCK_SHARED)
 290		mrunlock_shared(&ip->i_iolock);
 291
 292	if (lock_flags & XFS_MMAPLOCK_EXCL)
 293		mrunlock_excl(&ip->i_mmaplock);
 294	else if (lock_flags & XFS_MMAPLOCK_SHARED)
 295		mrunlock_shared(&ip->i_mmaplock);
 296
 297	if (lock_flags & XFS_ILOCK_EXCL)
 298		mrunlock_excl(&ip->i_lock);
 299	else if (lock_flags & XFS_ILOCK_SHARED)
 300		mrunlock_shared(&ip->i_lock);
 301
 302	trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
 303}
 304
 305/*
 306 * give up write locks.  the i/o lock cannot be held nested
 307 * if it is being demoted.
 308 */
 309void
 310xfs_ilock_demote(
 311	xfs_inode_t		*ip,
 312	uint			lock_flags)
 313{
 314	ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL));
 315	ASSERT((lock_flags &
 316		~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
 317
 318	if (lock_flags & XFS_ILOCK_EXCL)
 319		mrdemote(&ip->i_lock);
 320	if (lock_flags & XFS_MMAPLOCK_EXCL)
 321		mrdemote(&ip->i_mmaplock);
 322	if (lock_flags & XFS_IOLOCK_EXCL)
 323		mrdemote(&ip->i_iolock);
 324
 325	trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
 326}
 327
 328#if defined(DEBUG) || defined(XFS_WARN)
 329int
 330xfs_isilocked(
 331	xfs_inode_t		*ip,
 332	uint			lock_flags)
 333{
 334	if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
 335		if (!(lock_flags & XFS_ILOCK_SHARED))
 336			return !!ip->i_lock.mr_writer;
 337		return rwsem_is_locked(&ip->i_lock.mr_lock);
 338	}
 339
 340	if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) {
 341		if (!(lock_flags & XFS_MMAPLOCK_SHARED))
 342			return !!ip->i_mmaplock.mr_writer;
 343		return rwsem_is_locked(&ip->i_mmaplock.mr_lock);
 344	}
 345
 346	if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
 347		if (!(lock_flags & XFS_IOLOCK_SHARED))
 348			return !!ip->i_iolock.mr_writer;
 349		return rwsem_is_locked(&ip->i_iolock.mr_lock);
 
 350	}
 351
 352	ASSERT(0);
 353	return 0;
 354}
 355#endif
 356
 357#ifdef DEBUG
 358int xfs_locked_n;
 359int xfs_small_retries;
 360int xfs_middle_retries;
 361int xfs_lots_retries;
 362int xfs_lock_delays;
 363#endif
 364
 365/*
 366 * xfs_lockdep_subclass_ok() is only used in an ASSERT, so is only called when
 367 * DEBUG or XFS_WARN is set. And MAX_LOCKDEP_SUBCLASSES is then only defined
 368 * when CONFIG_LOCKDEP is set. Hence the complex define below to avoid build
 369 * errors and warnings.
 370 */
 371#if (defined(DEBUG) || defined(XFS_WARN)) && defined(CONFIG_LOCKDEP)
 372static bool
 373xfs_lockdep_subclass_ok(
 374	int subclass)
 375{
 376	return subclass < MAX_LOCKDEP_SUBCLASSES;
 377}
 378#else
 379#define xfs_lockdep_subclass_ok(subclass)	(true)
 380#endif
 381
 382/*
 383 * Bump the subclass so xfs_lock_inodes() acquires each lock with a different
 384 * value. This can be called for any type of inode lock combination, including
 385 * parent locking. Care must be taken to ensure we don't overrun the subclass
 386 * storage fields in the class mask we build.
 387 */
 388static inline int
 389xfs_lock_inumorder(int lock_mode, int subclass)
 390{
 391	int	class = 0;
 392
 393	ASSERT(!(lock_mode & (XFS_ILOCK_PARENT | XFS_ILOCK_RTBITMAP |
 394			      XFS_ILOCK_RTSUM)));
 395	ASSERT(xfs_lockdep_subclass_ok(subclass));
 396
 397	if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) {
 398		ASSERT(subclass <= XFS_IOLOCK_MAX_SUBCLASS);
 399		ASSERT(xfs_lockdep_subclass_ok(subclass +
 400						XFS_IOLOCK_PARENT_VAL));
 401		class += subclass << XFS_IOLOCK_SHIFT;
 402		if (lock_mode & XFS_IOLOCK_PARENT)
 403			class += XFS_IOLOCK_PARENT_VAL << XFS_IOLOCK_SHIFT;
 404	}
 405
 406	if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) {
 407		ASSERT(subclass <= XFS_MMAPLOCK_MAX_SUBCLASS);
 408		class += subclass << XFS_MMAPLOCK_SHIFT;
 409	}
 410
 411	if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) {
 412		ASSERT(subclass <= XFS_ILOCK_MAX_SUBCLASS);
 413		class += subclass << XFS_ILOCK_SHIFT;
 414	}
 415
 416	return (lock_mode & ~XFS_LOCK_SUBCLASS_MASK) | class;
 417}
 418
 419/*
 420 * The following routine will lock n inodes in exclusive mode.  We assume the
 421 * caller calls us with the inodes in i_ino order.
 422 *
 423 * We need to detect deadlock where an inode that we lock is in the AIL and we
 424 * start waiting for another inode that is locked by a thread in a long running
 425 * transaction (such as truncate). This can result in deadlock since the long
 426 * running trans might need to wait for the inode we just locked in order to
 427 * push the tail and free space in the log.
 428 *
 429 * xfs_lock_inodes() can only be used to lock one type of lock at a time -
 430 * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
 431 * lock more than one at a time, lockdep will report false positives saying we
 432 * have violated locking orders.
 433 */
 434void
 435xfs_lock_inodes(
 436	xfs_inode_t	**ips,
 437	int		inodes,
 438	uint		lock_mode)
 439{
 440	int		attempts = 0, i, j, try_lock;
 441	xfs_log_item_t	*lp;
 442
 443	/*
 444	 * Currently supports between 2 and 5 inodes with exclusive locking.  We
 445	 * support an arbitrary depth of locking here, but absolute limits on
 446	 * inodes depend on the the type of locking and the limits placed by
 447	 * lockdep annotations in xfs_lock_inumorder.  These are all checked by
 448	 * the asserts.
 449	 */
 450	ASSERT(ips && inodes >= 2 && inodes <= 5);
 451	ASSERT(lock_mode & (XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL |
 452			    XFS_ILOCK_EXCL));
 453	ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED | XFS_MMAPLOCK_SHARED |
 454			      XFS_ILOCK_SHARED)));
 455	ASSERT(!(lock_mode & XFS_IOLOCK_EXCL) ||
 456		inodes <= XFS_IOLOCK_MAX_SUBCLASS + 1);
 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 = (xfs_log_item_t *)ips[j]->i_itemp;
 483				if (lp && (lp->li_flags & XFS_LI_IN_AIL))
 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#ifdef DEBUG
 524			xfs_lock_delays++;
 525#endif
 526		}
 527		i = 0;
 528		try_lock = 0;
 529		goto again;
 530	}
 531
 532#ifdef DEBUG
 533	if (attempts) {
 534		if (attempts < 5) xfs_small_retries++;
 535		else if (attempts < 100) xfs_middle_retries++;
 536		else xfs_lots_retries++;
 537	} else {
 538		xfs_locked_n++;
 539	}
 540#endif
 541}
 542
 543/*
 544 * xfs_lock_two_inodes() can only be used to lock one type of lock at a time -
 545 * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
 546 * lock more than one at a time, lockdep will report false positives saying we
 547 * have violated locking orders.
 
 
 548 */
 549void
 550xfs_lock_two_inodes(
 551	xfs_inode_t		*ip0,
 552	xfs_inode_t		*ip1,
 553	uint			lock_mode)
 
 554{
 555	xfs_inode_t		*temp;
 
 556	int			attempts = 0;
 557	xfs_log_item_t		*lp;
 558
 559	if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) {
 560		ASSERT(!(lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)));
 561		ASSERT(!(lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
 562	} else if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL))
 563		ASSERT(!(lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
 
 
 
 
 
 
 
 564
 565	ASSERT(ip0->i_ino != ip1->i_ino);
 566
 567	if (ip0->i_ino > ip1->i_ino) {
 568		temp = ip0;
 569		ip0 = ip1;
 570		ip1 = temp;
 
 
 
 571	}
 572
 573 again:
 574	xfs_ilock(ip0, xfs_lock_inumorder(lock_mode, 0));
 575
 576	/*
 577	 * If the first lock we have locked is in the AIL, we must TRY to get
 578	 * the second lock. If we can't get it, we must release the first one
 579	 * and try again.
 580	 */
 581	lp = (xfs_log_item_t *)ip0->i_itemp;
 582	if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
 583		if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(lock_mode, 1))) {
 584			xfs_iunlock(ip0, lock_mode);
 585			if ((++attempts % 5) == 0)
 586				delay(1); /* Don't just spin the CPU */
 587			goto again;
 588		}
 589	} else {
 590		xfs_ilock(ip1, xfs_lock_inumorder(lock_mode, 1));
 591	}
 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.wait, TASK_UNINTERRUPTIBLE);
 604		if (xfs_isiflocked(ip))
 605			io_schedule();
 606	} while (!xfs_iflock_nowait(ip));
 607
 608	finish_wait(wq, &wait.wait);
 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	}
 654
 655	if (has_attr)
 656		flags |= FS_XFLAG_HASATTR;
 657
 658	return flags;
 659}
 660
 661uint
 662xfs_ip2xflags(
 663	struct xfs_inode	*ip)
 664{
 665	struct xfs_icdinode	*dic = &ip->i_d;
 666
 667	return _xfs_dic2xflags(dic->di_flags, dic->di_flags2, XFS_IFORK_Q(ip));
 668}
 669
 670uint
 671xfs_dic2xflags(
 672	struct xfs_dinode	*dip)
 673{
 674	return _xfs_dic2xflags(be16_to_cpu(dip->di_flags),
 675				be64_to_cpu(dip->di_flags2), XFS_DFORK_Q(dip));
 676}
 677
 678/*
 679 * Lookups up an inode from "name". If ci_name is not NULL, then a CI match
 680 * is allowed, otherwise it has to be an exact match. If a CI match is found,
 681 * ci_name->name will point to a the actual name (caller must free) or
 682 * will be set to NULL if an exact match is found.
 683 */
 684int
 685xfs_lookup(
 686	xfs_inode_t		*dp,
 687	struct xfs_name		*name,
 688	xfs_inode_t		**ipp,
 689	struct xfs_name		*ci_name)
 690{
 691	xfs_ino_t		inum;
 692	int			error;
 693
 694	trace_xfs_lookup(dp, name);
 695
 696	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
 697		return -EIO;
 698
 699	xfs_ilock(dp, XFS_IOLOCK_SHARED);
 700	error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
 701	if (error)
 702		goto out_unlock;
 703
 704	error = xfs_iget(dp->i_mount, NULL, inum, 0, 0, ipp);
 705	if (error)
 706		goto out_free_name;
 707
 708	xfs_iunlock(dp, XFS_IOLOCK_SHARED);
 709	return 0;
 710
 711out_free_name:
 712	if (ci_name)
 713		kmem_free(ci_name->name);
 714out_unlock:
 715	xfs_iunlock(dp, XFS_IOLOCK_SHARED);
 716	*ipp = NULL;
 717	return error;
 718}
 719
 720/*
 721 * Allocate an inode on disk and return a copy of its in-core version.
 722 * The in-core inode is locked exclusively.  Set mode, nlink, and rdev
 723 * appropriately within the inode.  The uid and gid for the inode are
 724 * set according to the contents of the given cred structure.
 725 *
 726 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
 727 * has a free inode available, call xfs_iget() to obtain the in-core
 728 * version of the allocated inode.  Finally, fill in the inode and
 729 * log its initial contents.  In this case, ialloc_context would be
 730 * set to NULL.
 731 *
 732 * If xfs_dialloc() does not have an available inode, it will replenish
 733 * its supply by doing an allocation. Since we can only do one
 734 * allocation within a transaction without deadlocks, we must commit
 735 * the current transaction before returning the inode itself.
 736 * In this case, therefore, we will set ialloc_context and return.
 737 * The caller should then commit the current transaction, start a new
 738 * transaction, and call xfs_ialloc() again to actually get the inode.
 739 *
 740 * To ensure that some other process does not grab the inode that
 741 * was allocated during the first call to xfs_ialloc(), this routine
 742 * also returns the [locked] bp pointing to the head of the freelist
 743 * as ialloc_context.  The caller should hold this buffer across
 744 * the commit and pass it back into this routine on the second call.
 745 *
 746 * If we are allocating quota inodes, we do not have a parent inode
 747 * to attach to or associate with (i.e. pip == NULL) because they
 748 * are not linked into the directory structure - they are attached
 749 * directly to the superblock - and so have no parent.
 750 */
 751int
 752xfs_ialloc(
 753	xfs_trans_t	*tp,
 754	xfs_inode_t	*pip,
 755	umode_t		mode,
 756	xfs_nlink_t	nlink,
 757	xfs_dev_t	rdev,
 758	prid_t		prid,
 759	int		okalloc,
 760	xfs_buf_t	**ialloc_context,
 761	xfs_inode_t	**ipp)
 762{
 763	struct xfs_mount *mp = tp->t_mountp;
 764	xfs_ino_t	ino;
 765	xfs_inode_t	*ip;
 766	uint		flags;
 767	int		error;
 768	struct timespec	tv;
 769	struct inode	*inode;
 770
 771	/*
 772	 * Call the space management code to pick
 773	 * the on-disk inode to be allocated.
 774	 */
 775	error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode, okalloc,
 776			    ialloc_context, &ino);
 777	if (error)
 778		return error;
 779	if (*ialloc_context || ino == NULLFSINO) {
 780		*ipp = NULL;
 781		return 0;
 782	}
 783	ASSERT(*ialloc_context == NULL);
 784
 785	/*
 
 
 
 
 
 
 
 
 
 
 
 
 786	 * Get the in-core inode with the lock held exclusively.
 787	 * This is because we're setting fields here we need
 788	 * to prevent others from looking at until we're done.
 789	 */
 790	error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE,
 791			 XFS_ILOCK_EXCL, &ip);
 792	if (error)
 793		return error;
 794	ASSERT(ip != NULL);
 795	inode = VFS_I(ip);
 796
 797	/*
 798	 * We always convert v1 inodes to v2 now - we only support filesystems
 799	 * with >= v2 inode capability, so there is no reason for ever leaving
 800	 * an inode in v1 format.
 801	 */
 802	if (ip->i_d.di_version == 1)
 803		ip->i_d.di_version = 2;
 804
 805	inode->i_mode = mode;
 806	set_nlink(inode, nlink);
 807	ip->i_d.di_uid = xfs_kuid_to_uid(current_fsuid());
 808	ip->i_d.di_gid = xfs_kgid_to_gid(current_fsgid());
 
 809	xfs_set_projid(ip, prid);
 810
 811	if (pip && XFS_INHERIT_GID(pip)) {
 812		ip->i_d.di_gid = pip->i_d.di_gid;
 813		if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode))
 814			inode->i_mode |= S_ISGID;
 815	}
 816
 817	/*
 818	 * If the group ID of the new file does not match the effective group
 819	 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
 820	 * (and only if the irix_sgid_inherit compatibility variable is set).
 821	 */
 822	if ((irix_sgid_inherit) &&
 823	    (inode->i_mode & S_ISGID) &&
 824	    (!in_group_p(xfs_gid_to_kgid(ip->i_d.di_gid))))
 825		inode->i_mode &= ~S_ISGID;
 826
 827	ip->i_d.di_size = 0;
 828	ip->i_d.di_nextents = 0;
 829	ASSERT(ip->i_d.di_nblocks == 0);
 830
 831	tv = current_fs_time(mp->m_super);
 832	inode->i_mtime = tv;
 833	inode->i_atime = tv;
 834	inode->i_ctime = tv;
 835
 836	ip->i_d.di_extsize = 0;
 837	ip->i_d.di_dmevmask = 0;
 838	ip->i_d.di_dmstate = 0;
 839	ip->i_d.di_flags = 0;
 840
 841	if (ip->i_d.di_version == 3) {
 842		inode->i_version = 1;
 843		ip->i_d.di_flags2 = 0;
 844		ip->i_d.di_crtime.t_sec = (__int32_t)tv.tv_sec;
 845		ip->i_d.di_crtime.t_nsec = (__int32_t)tv.tv_nsec;
 
 846	}
 847
 848
 849	flags = XFS_ILOG_CORE;
 850	switch (mode & S_IFMT) {
 851	case S_IFIFO:
 852	case S_IFCHR:
 853	case S_IFBLK:
 854	case S_IFSOCK:
 855		ip->i_d.di_format = XFS_DINODE_FMT_DEV;
 856		ip->i_df.if_u2.if_rdev = rdev;
 857		ip->i_df.if_flags = 0;
 858		flags |= XFS_ILOG_DEV;
 859		break;
 860	case S_IFREG:
 861	case S_IFDIR:
 862		if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
 863			uint64_t	di_flags2 = 0;
 864			uint		di_flags = 0;
 865
 866			if (S_ISDIR(mode)) {
 867				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
 868					di_flags |= XFS_DIFLAG_RTINHERIT;
 869				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
 870					di_flags |= XFS_DIFLAG_EXTSZINHERIT;
 871					ip->i_d.di_extsize = pip->i_d.di_extsize;
 872				}
 873				if (pip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
 874					di_flags |= XFS_DIFLAG_PROJINHERIT;
 875			} else if (S_ISREG(mode)) {
 876				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
 877					di_flags |= XFS_DIFLAG_REALTIME;
 878				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
 879					di_flags |= XFS_DIFLAG_EXTSIZE;
 880					ip->i_d.di_extsize = pip->i_d.di_extsize;
 881				}
 882			}
 883			if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
 884			    xfs_inherit_noatime)
 885				di_flags |= XFS_DIFLAG_NOATIME;
 886			if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
 887			    xfs_inherit_nodump)
 888				di_flags |= XFS_DIFLAG_NODUMP;
 889			if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
 890			    xfs_inherit_sync)
 891				di_flags |= XFS_DIFLAG_SYNC;
 892			if ((pip->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) &&
 893			    xfs_inherit_nosymlinks)
 894				di_flags |= XFS_DIFLAG_NOSYMLINKS;
 895			if ((pip->i_d.di_flags & XFS_DIFLAG_NODEFRAG) &&
 896			    xfs_inherit_nodefrag)
 897				di_flags |= XFS_DIFLAG_NODEFRAG;
 898			if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
 899				di_flags |= XFS_DIFLAG_FILESTREAM;
 
 
 
 
 
 
 
 
 
 
 
 
 
 900			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
 901				di_flags2 |= XFS_DIFLAG2_DAX;
 902
 903			ip->i_d.di_flags |= di_flags;
 904			ip->i_d.di_flags2 |= di_flags2;
 905		}
 906		/* FALLTHROUGH */
 907	case S_IFLNK:
 908		ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
 909		ip->i_df.if_flags = XFS_IFEXTENTS;
 910		ip->i_df.if_bytes = ip->i_df.if_real_bytes = 0;
 911		ip->i_df.if_u1.if_extents = NULL;
 912		break;
 913	default:
 914		ASSERT(0);
 915	}
 916	/*
 917	 * Attribute fork settings for new inode.
 918	 */
 919	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
 920	ip->i_d.di_anextents = 0;
 921
 922	/*
 923	 * Log the new values stuffed into the inode.
 924	 */
 925	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 926	xfs_trans_log_inode(tp, ip, flags);
 927
 928	/* now that we have an i_mode we can setup the inode structure */
 929	xfs_setup_inode(ip);
 930
 931	*ipp = ip;
 932	return 0;
 933}
 934
 935/*
 936 * Allocates a new inode from disk and return a pointer to the
 937 * incore copy. This routine will internally commit the current
 938 * transaction and allocate a new one if the Space Manager needed
 939 * to do an allocation to replenish the inode free-list.
 940 *
 941 * This routine is designed to be called from xfs_create and
 942 * xfs_create_dir.
 943 *
 944 */
 945int
 946xfs_dir_ialloc(
 947	xfs_trans_t	**tpp,		/* input: current transaction;
 948					   output: may be a new transaction. */
 949	xfs_inode_t	*dp,		/* directory within whose allocate
 950					   the inode. */
 951	umode_t		mode,
 952	xfs_nlink_t	nlink,
 953	xfs_dev_t	rdev,
 954	prid_t		prid,		/* project id */
 955	int		okalloc,	/* ok to allocate new space */
 956	xfs_inode_t	**ipp,		/* pointer to inode; it will be
 957					   locked. */
 958	int		*committed)
 959
 960{
 961	xfs_trans_t	*tp;
 962	xfs_inode_t	*ip;
 963	xfs_buf_t	*ialloc_context = NULL;
 964	int		code;
 965	void		*dqinfo;
 966	uint		tflags;
 967
 968	tp = *tpp;
 969	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
 970
 971	/*
 972	 * xfs_ialloc will return a pointer to an incore inode if
 973	 * the Space Manager has an available inode on the free
 974	 * list. Otherwise, it will do an allocation and replenish
 975	 * the freelist.  Since we can only do one allocation per
 976	 * transaction without deadlocks, we will need to commit the
 977	 * current transaction and start a new one.  We will then
 978	 * need to call xfs_ialloc again to get the inode.
 979	 *
 980	 * If xfs_ialloc did an allocation to replenish the freelist,
 981	 * it returns the bp containing the head of the freelist as
 982	 * ialloc_context. We will hold a lock on it across the
 983	 * transaction commit so that no other process can steal
 984	 * the inode(s) that we've just allocated.
 985	 */
 986	code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, okalloc,
 987			  &ialloc_context, &ip);
 988
 989	/*
 990	 * Return an error if we were unable to allocate a new inode.
 991	 * This should only happen if we run out of space on disk or
 992	 * encounter a disk error.
 993	 */
 994	if (code) {
 995		*ipp = NULL;
 996		return code;
 997	}
 998	if (!ialloc_context && !ip) {
 999		*ipp = NULL;
1000		return -ENOSPC;
1001	}
1002
1003	/*
1004	 * If the AGI buffer is non-NULL, then we were unable to get an
1005	 * inode in one operation.  We need to commit the current
1006	 * transaction and call xfs_ialloc() again.  It is guaranteed
1007	 * to succeed the second time.
1008	 */
1009	if (ialloc_context) {
1010		/*
1011		 * Normally, xfs_trans_commit releases all the locks.
1012		 * We call bhold to hang on to the ialloc_context across
1013		 * the commit.  Holding this buffer prevents any other
1014		 * processes from doing any allocations in this
1015		 * allocation group.
1016		 */
1017		xfs_trans_bhold(tp, ialloc_context);
1018
1019		/*
1020		 * We want the quota changes to be associated with the next
1021		 * transaction, NOT this one. So, detach the dqinfo from this
1022		 * and attach it to the next transaction.
1023		 */
1024		dqinfo = NULL;
1025		tflags = 0;
1026		if (tp->t_dqinfo) {
1027			dqinfo = (void *)tp->t_dqinfo;
1028			tp->t_dqinfo = NULL;
1029			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
1030			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
1031		}
1032
1033		code = xfs_trans_roll(&tp, 0);
1034		if (committed != NULL)
1035			*committed = 1;
1036
1037		/*
1038		 * Re-attach the quota info that we detached from prev trx.
1039		 */
1040		if (dqinfo) {
1041			tp->t_dqinfo = dqinfo;
1042			tp->t_flags |= tflags;
1043		}
1044
1045		if (code) {
1046			xfs_buf_relse(ialloc_context);
1047			*tpp = tp;
1048			*ipp = NULL;
1049			return code;
1050		}
1051		xfs_trans_bjoin(tp, ialloc_context);
1052
1053		/*
1054		 * Call ialloc again. Since we've locked out all
1055		 * other allocations in this allocation group,
1056		 * this call should always succeed.
1057		 */
1058		code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
1059				  okalloc, &ialloc_context, &ip);
1060
1061		/*
1062		 * If we get an error at this point, return to the caller
1063		 * so that the current transaction can be aborted.
1064		 */
1065		if (code) {
1066			*tpp = tp;
1067			*ipp = NULL;
1068			return code;
1069		}
1070		ASSERT(!ialloc_context && ip);
1071
1072	} else {
1073		if (committed != NULL)
1074			*committed = 0;
1075	}
1076
1077	*ipp = ip;
1078	*tpp = tp;
1079
1080	return 0;
1081}
1082
1083/*
1084 * Decrement the link count on an inode & log the change.  If this causes the
1085 * link count to go to zero, move the inode to AGI unlinked list so that it can
1086 * be freed when the last active reference goes away via xfs_inactive().
1087 */
1088int				/* error */
1089xfs_droplink(
1090	xfs_trans_t *tp,
1091	xfs_inode_t *ip)
1092{
1093	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1094
1095	drop_nlink(VFS_I(ip));
1096	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1097
1098	if (VFS_I(ip)->i_nlink)
1099		return 0;
1100
1101	return xfs_iunlink(tp, ip);
1102}
1103
1104/*
1105 * Increment the link count on an inode & log the change.
1106 */
1107int
1108xfs_bumplink(
1109	xfs_trans_t *tp,
1110	xfs_inode_t *ip)
1111{
1112	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1113
1114	ASSERT(ip->i_d.di_version > 1);
1115	inc_nlink(VFS_I(ip));
1116	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1117	return 0;
1118}
1119
1120int
1121xfs_create(
1122	xfs_inode_t		*dp,
1123	struct xfs_name		*name,
1124	umode_t			mode,
1125	xfs_dev_t		rdev,
1126	xfs_inode_t		**ipp)
1127{
1128	int			is_dir = S_ISDIR(mode);
1129	struct xfs_mount	*mp = dp->i_mount;
1130	struct xfs_inode	*ip = NULL;
1131	struct xfs_trans	*tp = NULL;
1132	int			error;
1133	xfs_bmap_free_t		free_list;
1134	xfs_fsblock_t		first_block;
1135	bool                    unlock_dp_on_error = false;
1136	prid_t			prid;
1137	struct xfs_dquot	*udqp = NULL;
1138	struct xfs_dquot	*gdqp = NULL;
1139	struct xfs_dquot	*pdqp = NULL;
1140	struct xfs_trans_res	*tres;
1141	uint			resblks;
1142
1143	trace_xfs_create(dp, name);
1144
1145	if (XFS_FORCED_SHUTDOWN(mp))
1146		return -EIO;
1147
1148	prid = xfs_get_initial_prid(dp);
1149
1150	/*
1151	 * Make sure that we have allocated dquot(s) on disk.
1152	 */
1153	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1154					xfs_kgid_to_gid(current_fsgid()), prid,
1155					XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1156					&udqp, &gdqp, &pdqp);
1157	if (error)
1158		return error;
1159
1160	if (is_dir) {
1161		rdev = 0;
1162		resblks = XFS_MKDIR_SPACE_RES(mp, name->len);
1163		tres = &M_RES(mp)->tr_mkdir;
1164		tp = xfs_trans_alloc(mp, XFS_TRANS_MKDIR);
1165	} else {
1166		resblks = XFS_CREATE_SPACE_RES(mp, name->len);
1167		tres = &M_RES(mp)->tr_create;
1168		tp = xfs_trans_alloc(mp, XFS_TRANS_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_reserve(tp, tres, resblks, 0);
1178	if (error == -ENOSPC) {
1179		/* flush outstanding delalloc blocks and retry */
1180		xfs_flush_inodes(mp);
1181		error = xfs_trans_reserve(tp, tres, resblks, 0);
1182	}
1183	if (error == -ENOSPC) {
1184		/* No space at all so try a "no-allocation" reservation */
1185		resblks = 0;
1186		error = xfs_trans_reserve(tp, tres, 0, 0);
1187	}
1188	if (error)
1189		goto out_trans_cancel;
1190
1191
1192	xfs_ilock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL |
1193		      XFS_IOLOCK_PARENT | XFS_ILOCK_PARENT);
1194	unlock_dp_on_error = true;
1195
1196	xfs_bmap_init(&free_list, &first_block);
1197
1198	/*
1199	 * Reserve disk quota and the inode.
1200	 */
1201	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1202						pdqp, resblks, 1, 0);
1203	if (error)
1204		goto out_trans_cancel;
1205
1206	if (!resblks) {
1207		error = xfs_dir_canenter(tp, dp, name);
1208		if (error)
1209			goto out_trans_cancel;
1210	}
1211
1212	/*
1213	 * A newly created regular or special file just has one directory
1214	 * entry pointing to them, but a directory also the "." entry
1215	 * pointing to itself.
1216	 */
1217	error = xfs_dir_ialloc(&tp, dp, mode, is_dir ? 2 : 1, rdev,
1218			       prid, resblks > 0, &ip, NULL);
1219	if (error)
1220		goto out_trans_cancel;
1221
1222	/*
1223	 * Now we join the directory inode to the transaction.  We do not do it
1224	 * earlier because xfs_dir_ialloc might commit the previous transaction
1225	 * (and release all the locks).  An error from here on will result in
1226	 * the transaction cancel unlocking dp so don't do it explicitly in the
1227	 * error path.
1228	 */
1229	xfs_trans_ijoin(tp, dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1230	unlock_dp_on_error = false;
1231
1232	error = xfs_dir_createname(tp, dp, name, ip->i_ino,
1233					&first_block, &free_list, resblks ?
1234					resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
1235	if (error) {
1236		ASSERT(error != -ENOSPC);
1237		goto out_trans_cancel;
1238	}
1239	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1240	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1241
1242	if (is_dir) {
1243		error = xfs_dir_init(tp, ip, dp);
1244		if (error)
1245			goto out_bmap_cancel;
1246
1247		error = xfs_bumplink(tp, dp);
1248		if (error)
1249			goto out_bmap_cancel;
1250	}
1251
1252	/*
1253	 * If this is a synchronous mount, make sure that the
1254	 * create transaction goes to disk before returning to
1255	 * the user.
1256	 */
1257	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1258		xfs_trans_set_sync(tp);
1259
1260	/*
1261	 * Attach the dquot(s) to the inodes and modify them incore.
1262	 * These ids of the inode couldn't have changed since the new
1263	 * inode has been locked ever since it was created.
1264	 */
1265	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1266
1267	error = xfs_bmap_finish(&tp, &free_list, NULL);
1268	if (error)
1269		goto out_bmap_cancel;
1270
1271	error = xfs_trans_commit(tp);
1272	if (error)
1273		goto out_release_inode;
1274
1275	xfs_qm_dqrele(udqp);
1276	xfs_qm_dqrele(gdqp);
1277	xfs_qm_dqrele(pdqp);
1278
1279	*ipp = ip;
1280	return 0;
1281
1282 out_bmap_cancel:
1283	xfs_bmap_cancel(&free_list);
1284 out_trans_cancel:
1285	xfs_trans_cancel(tp);
1286 out_release_inode:
1287	/*
1288	 * Wait until after the current transaction is aborted to finish the
1289	 * setup of the inode and release the inode.  This prevents recursive
1290	 * transactions and deadlocks from xfs_inactive.
1291	 */
1292	if (ip) {
1293		xfs_finish_inode_setup(ip);
1294		IRELE(ip);
1295	}
1296
1297	xfs_qm_dqrele(udqp);
1298	xfs_qm_dqrele(gdqp);
1299	xfs_qm_dqrele(pdqp);
1300
1301	if (unlock_dp_on_error)
1302		xfs_iunlock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1303	return error;
1304}
1305
1306int
1307xfs_create_tmpfile(
1308	struct xfs_inode	*dp,
1309	struct dentry		*dentry,
1310	umode_t			mode,
1311	struct xfs_inode	**ipp)
1312{
1313	struct xfs_mount	*mp = dp->i_mount;
1314	struct xfs_inode	*ip = NULL;
1315	struct xfs_trans	*tp = NULL;
1316	int			error;
1317	prid_t                  prid;
1318	struct xfs_dquot	*udqp = NULL;
1319	struct xfs_dquot	*gdqp = NULL;
1320	struct xfs_dquot	*pdqp = NULL;
1321	struct xfs_trans_res	*tres;
1322	uint			resblks;
1323
1324	if (XFS_FORCED_SHUTDOWN(mp))
1325		return -EIO;
1326
1327	prid = xfs_get_initial_prid(dp);
1328
1329	/*
1330	 * Make sure that we have allocated dquot(s) on disk.
1331	 */
1332	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1333				xfs_kgid_to_gid(current_fsgid()), prid,
1334				XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1335				&udqp, &gdqp, &pdqp);
1336	if (error)
1337		return error;
1338
1339	resblks = XFS_IALLOC_SPACE_RES(mp);
1340	tp = xfs_trans_alloc(mp, XFS_TRANS_CREATE_TMPFILE);
1341
1342	tres = &M_RES(mp)->tr_create_tmpfile;
1343	error = xfs_trans_reserve(tp, tres, resblks, 0);
1344	if (error == -ENOSPC) {
1345		/* No space at all so try a "no-allocation" reservation */
1346		resblks = 0;
1347		error = xfs_trans_reserve(tp, tres, 0, 0);
1348	}
1349	if (error)
1350		goto out_trans_cancel;
1351
1352	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1353						pdqp, resblks, 1, 0);
1354	if (error)
1355		goto out_trans_cancel;
1356
1357	error = xfs_dir_ialloc(&tp, dp, mode, 1, 0,
1358				prid, resblks > 0, &ip, NULL);
1359	if (error)
1360		goto out_trans_cancel;
1361
1362	if (mp->m_flags & XFS_MOUNT_WSYNC)
1363		xfs_trans_set_sync(tp);
1364
1365	/*
1366	 * Attach the dquot(s) to the inodes and modify them incore.
1367	 * These ids of the inode couldn't have changed since the new
1368	 * inode has been locked ever since it was created.
1369	 */
1370	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1371
1372	error = xfs_iunlink(tp, ip);
1373	if (error)
1374		goto out_trans_cancel;
1375
1376	error = xfs_trans_commit(tp);
1377	if (error)
1378		goto out_release_inode;
1379
1380	xfs_qm_dqrele(udqp);
1381	xfs_qm_dqrele(gdqp);
1382	xfs_qm_dqrele(pdqp);
1383
1384	*ipp = ip;
1385	return 0;
1386
1387 out_trans_cancel:
1388	xfs_trans_cancel(tp);
1389 out_release_inode:
1390	/*
1391	 * Wait until after the current transaction is aborted to finish the
1392	 * setup of the inode and release the inode.  This prevents recursive
1393	 * transactions and deadlocks from xfs_inactive.
1394	 */
1395	if (ip) {
1396		xfs_finish_inode_setup(ip);
1397		IRELE(ip);
1398	}
1399
1400	xfs_qm_dqrele(udqp);
1401	xfs_qm_dqrele(gdqp);
1402	xfs_qm_dqrele(pdqp);
1403
1404	return error;
1405}
1406
1407int
1408xfs_link(
1409	xfs_inode_t		*tdp,
1410	xfs_inode_t		*sip,
1411	struct xfs_name		*target_name)
1412{
1413	xfs_mount_t		*mp = tdp->i_mount;
1414	xfs_trans_t		*tp;
1415	int			error;
1416	xfs_bmap_free_t         free_list;
1417	xfs_fsblock_t           first_block;
1418	int			resblks;
1419
1420	trace_xfs_link(tdp, target_name);
1421
1422	ASSERT(!S_ISDIR(VFS_I(sip)->i_mode));
1423
1424	if (XFS_FORCED_SHUTDOWN(mp))
1425		return -EIO;
1426
1427	error = xfs_qm_dqattach(sip, 0);
1428	if (error)
1429		goto std_return;
1430
1431	error = xfs_qm_dqattach(tdp, 0);
1432	if (error)
1433		goto std_return;
1434
1435	tp = xfs_trans_alloc(mp, XFS_TRANS_LINK);
1436	resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
1437	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_link, resblks, 0);
1438	if (error == -ENOSPC) {
1439		resblks = 0;
1440		error = xfs_trans_reserve(tp, &M_RES(mp)->tr_link, 0, 0);
1441	}
1442	if (error)
1443		goto error_return;
1444
1445	xfs_ilock(tdp, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
1446	xfs_lock_two_inodes(sip, tdp, XFS_ILOCK_EXCL);
1447
1448	xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
1449	xfs_trans_ijoin(tp, tdp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
1450
1451	/*
1452	 * If we are using project inheritance, we only allow hard link
1453	 * creation in our tree when the project IDs are the same; else
1454	 * the tree quota mechanism could be circumvented.
1455	 */
1456	if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
1457		     (xfs_get_projid(tdp) != xfs_get_projid(sip)))) {
1458		error = -EXDEV;
1459		goto error_return;
1460	}
1461
1462	if (!resblks) {
1463		error = xfs_dir_canenter(tp, tdp, target_name);
1464		if (error)
1465			goto error_return;
1466	}
1467
1468	xfs_bmap_init(&free_list, &first_block);
1469
1470	/*
1471	 * Handle initial link state of O_TMPFILE inode
1472	 */
1473	if (VFS_I(sip)->i_nlink == 0) {
1474		error = xfs_iunlink_remove(tp, sip);
1475		if (error)
1476			goto error_return;
1477	}
1478
1479	error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
1480					&first_block, &free_list, resblks);
1481	if (error)
1482		goto error_return;
1483	xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1484	xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
1485
1486	error = xfs_bumplink(tp, sip);
1487	if (error)
1488		goto error_return;
1489
1490	/*
1491	 * If this is a synchronous mount, make sure that the
1492	 * link transaction goes to disk before returning to
1493	 * the user.
1494	 */
1495	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1496		xfs_trans_set_sync(tp);
1497
1498	error = xfs_bmap_finish(&tp, &free_list, NULL);
1499	if (error) {
1500		xfs_bmap_cancel(&free_list);
1501		goto error_return;
1502	}
1503
1504	return xfs_trans_commit(tp);
1505
1506 error_return:
1507	xfs_trans_cancel(tp);
1508 std_return:
1509	return error;
1510}
1511
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1512/*
1513 * Free up the underlying blocks past new_size.  The new size must be smaller
1514 * than the current size.  This routine can be used both for the attribute and
1515 * data fork, and does not modify the inode size, which is left to the caller.
1516 *
1517 * The transaction passed to this routine must have made a permanent log
1518 * reservation of at least XFS_ITRUNCATE_LOG_RES.  This routine may commit the
1519 * given transaction and start new ones, so make sure everything involved in
1520 * the transaction is tidy before calling here.  Some transaction will be
1521 * returned to the caller to be committed.  The incoming transaction must
1522 * already include the inode, and both inode locks must be held exclusively.
1523 * The inode must also be "held" within the transaction.  On return the inode
1524 * will be "held" within the returned transaction.  This routine does NOT
1525 * require any disk space to be reserved for it within the transaction.
1526 *
1527 * If we get an error, we must return with the inode locked and linked into the
1528 * current transaction. This keeps things simple for the higher level code,
1529 * because it always knows that the inode is locked and held in the transaction
1530 * that returns to it whether errors occur or not.  We don't mark the inode
1531 * dirty on error so that transactions can be easily aborted if possible.
1532 */
1533int
1534xfs_itruncate_extents(
1535	struct xfs_trans	**tpp,
1536	struct xfs_inode	*ip,
1537	int			whichfork,
1538	xfs_fsize_t		new_size)
 
1539{
1540	struct xfs_mount	*mp = ip->i_mount;
1541	struct xfs_trans	*tp = *tpp;
1542	xfs_bmap_free_t		free_list;
1543	xfs_fsblock_t		first_block;
1544	xfs_fileoff_t		first_unmap_block;
1545	xfs_fileoff_t		last_block;
1546	xfs_filblks_t		unmap_len;
1547	int			error = 0;
1548	int			done = 0;
1549
1550	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1551	ASSERT(!atomic_read(&VFS_I(ip)->i_count) ||
1552	       xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1553	ASSERT(new_size <= XFS_ISIZE(ip));
1554	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
1555	ASSERT(ip->i_itemp != NULL);
1556	ASSERT(ip->i_itemp->ili_lock_flags == 0);
1557	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1558
1559	trace_xfs_itruncate_extents_start(ip, new_size);
1560
 
 
1561	/*
1562	 * Since it is possible for space to become allocated beyond
1563	 * the end of the file (in a crash where the space is allocated
1564	 * but the inode size is not yet updated), simply remove any
1565	 * blocks which show up between the new EOF and the maximum
1566	 * possible file size.  If the first block to be removed is
1567	 * beyond the maximum file size (ie it is the same as last_block),
1568	 * then there is nothing to do.
1569	 */
1570	first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
1571	last_block = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
1572	if (first_unmap_block == last_block)
1573		return 0;
1574
1575	ASSERT(first_unmap_block < last_block);
1576	unmap_len = last_block - first_unmap_block + 1;
1577	while (!done) {
1578		xfs_bmap_init(&free_list, &first_block);
1579		error = xfs_bunmapi(tp, ip,
1580				    first_unmap_block, unmap_len,
1581				    xfs_bmapi_aflag(whichfork),
1582				    XFS_ITRUNC_MAX_EXTENTS,
1583				    &first_block, &free_list,
1584				    &done);
1585		if (error)
1586			goto out_bmap_cancel;
1587
1588		/*
1589		 * Duplicate the transaction that has the permanent
1590		 * reservation and commit the old transaction.
1591		 */
1592		error = xfs_bmap_finish(&tp, &free_list, ip);
 
 
 
 
1593		if (error)
1594			goto out_bmap_cancel;
 
1595
1596		error = xfs_trans_roll(&tp, ip);
 
 
 
1597		if (error)
1598			goto out;
 
 
1599	}
1600
1601	/*
1602	 * Always re-log the inode so that our permanent transaction can keep
1603	 * on rolling it forward in the log.
1604	 */
1605	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1606
1607	trace_xfs_itruncate_extents_end(ip, new_size);
1608
1609out:
1610	*tpp = tp;
1611	return error;
1612out_bmap_cancel:
1613	/*
1614	 * If the bunmapi call encounters an error, return to the caller where
1615	 * the transaction can be properly aborted.  We just need to make sure
1616	 * we're not holding any resources that we were not when we came in.
1617	 */
1618	xfs_bmap_cancel(&free_list);
1619	goto out;
1620}
1621
1622int
1623xfs_release(
1624	xfs_inode_t	*ip)
1625{
1626	xfs_mount_t	*mp = ip->i_mount;
1627	int		error;
1628
1629	if (!S_ISREG(VFS_I(ip)->i_mode) || (VFS_I(ip)->i_mode == 0))
1630		return 0;
1631
1632	/* If this is a read-only mount, don't do this (would generate I/O) */
1633	if (mp->m_flags & XFS_MOUNT_RDONLY)
1634		return 0;
1635
1636	if (!XFS_FORCED_SHUTDOWN(mp)) {
1637		int truncated;
1638
1639		/*
1640		 * If we previously truncated this file and removed old data
1641		 * in the process, we want to initiate "early" writeout on
1642		 * the last close.  This is an attempt to combat the notorious
1643		 * NULL files problem which is particularly noticeable from a
1644		 * truncate down, buffered (re-)write (delalloc), followed by
1645		 * a crash.  What we are effectively doing here is
1646		 * significantly reducing the time window where we'd otherwise
1647		 * be exposed to that problem.
1648		 */
1649		truncated = xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED);
1650		if (truncated) {
1651			xfs_iflags_clear(ip, XFS_IDIRTY_RELEASE);
1652			if (ip->i_delayed_blks > 0) {
1653				error = filemap_flush(VFS_I(ip)->i_mapping);
1654				if (error)
1655					return error;
1656			}
1657		}
1658	}
1659
1660	if (VFS_I(ip)->i_nlink == 0)
1661		return 0;
1662
1663	if (xfs_can_free_eofblocks(ip, false)) {
1664
1665		/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1666		 * If we can't get the iolock just skip truncating the blocks
1667		 * past EOF because we could deadlock with the mmap_sem
1668		 * otherwise.  We'll get another chance to drop them once the
1669		 * last reference to the inode is dropped, so we'll never leak
1670		 * blocks permanently.
1671		 *
1672		 * Further, check if the inode is being opened, written and
1673		 * closed frequently and we have delayed allocation blocks
1674		 * outstanding (e.g. streaming writes from the NFS server),
1675		 * truncating the blocks past EOF will cause fragmentation to
1676		 * occur.
1677		 *
1678		 * In this case don't do the truncation, either, but we have to
1679		 * be careful how we detect this case. Blocks beyond EOF show
1680		 * up as i_delayed_blks even when the inode is clean, so we
1681		 * need to truncate them away first before checking for a dirty
1682		 * release. Hence on the first dirty close we will still remove
1683		 * the speculative allocation, but after that we will leave it
1684		 * in place.
1685		 */
1686		if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
1687			return 0;
1688
1689		error = xfs_free_eofblocks(mp, ip, true);
1690		if (error && error != -EAGAIN)
1691			return error;
1692
1693		/* delalloc blocks after truncation means it really is dirty */
1694		if (ip->i_delayed_blks)
1695			xfs_iflags_set(ip, XFS_IDIRTY_RELEASE);
1696	}
1697	return 0;
1698}
1699
1700/*
1701 * xfs_inactive_truncate
1702 *
1703 * Called to perform a truncate when an inode becomes unlinked.
1704 */
1705STATIC int
1706xfs_inactive_truncate(
1707	struct xfs_inode *ip)
1708{
1709	struct xfs_mount	*mp = ip->i_mount;
1710	struct xfs_trans	*tp;
1711	int			error;
1712
1713	tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
1714	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
1715	if (error) {
1716		ASSERT(XFS_FORCED_SHUTDOWN(mp));
1717		xfs_trans_cancel(tp);
1718		return error;
1719	}
1720
1721	xfs_ilock(ip, XFS_ILOCK_EXCL);
1722	xfs_trans_ijoin(tp, ip, 0);
1723
1724	/*
1725	 * Log the inode size first to prevent stale data exposure in the event
1726	 * of a system crash before the truncate completes. See the related
1727	 * comment in xfs_setattr_size() for details.
1728	 */
1729	ip->i_d.di_size = 0;
1730	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1731
1732	error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
1733	if (error)
1734		goto error_trans_cancel;
1735
1736	ASSERT(ip->i_d.di_nextents == 0);
1737
1738	error = xfs_trans_commit(tp);
1739	if (error)
1740		goto error_unlock;
1741
1742	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1743	return 0;
1744
1745error_trans_cancel:
1746	xfs_trans_cancel(tp);
1747error_unlock:
1748	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1749	return error;
1750}
1751
1752/*
1753 * xfs_inactive_ifree()
1754 *
1755 * Perform the inode free when an inode is unlinked.
1756 */
1757STATIC int
1758xfs_inactive_ifree(
1759	struct xfs_inode *ip)
1760{
1761	xfs_bmap_free_t		free_list;
1762	xfs_fsblock_t		first_block;
1763	struct xfs_mount	*mp = ip->i_mount;
1764	struct xfs_trans	*tp;
1765	int			error;
1766
1767	tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
1768
1769	/*
1770	 * The ifree transaction might need to allocate blocks for record
1771	 * insertion to the finobt. We don't want to fail here at ENOSPC, so
1772	 * allow ifree to dip into the reserved block pool if necessary.
1773	 *
1774	 * Freeing large sets of inodes generally means freeing inode chunks,
1775	 * directory and file data blocks, so this should be relatively safe.
1776	 * Only under severe circumstances should it be possible to free enough
1777	 * inodes to exhaust the reserve block pool via finobt expansion while
1778	 * at the same time not creating free space in the filesystem.
1779	 *
1780	 * Send a warning if the reservation does happen to fail, as the inode
1781	 * now remains allocated and sits on the unlinked list until the fs is
1782	 * repaired.
1783	 */
1784	tp->t_flags |= XFS_TRANS_RESERVE;
1785	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ifree,
1786				  XFS_IFREE_SPACE_RES(mp), 0);
 
 
 
 
1787	if (error) {
1788		if (error == -ENOSPC) {
1789			xfs_warn_ratelimited(mp,
1790			"Failed to remove inode(s) from unlinked list. "
1791			"Please free space, unmount and run xfs_repair.");
1792		} else {
1793			ASSERT(XFS_FORCED_SHUTDOWN(mp));
1794		}
1795		xfs_trans_cancel(tp);
1796		return error;
1797	}
1798
1799	xfs_ilock(ip, XFS_ILOCK_EXCL);
1800	xfs_trans_ijoin(tp, ip, 0);
1801
1802	xfs_bmap_init(&free_list, &first_block);
1803	error = xfs_ifree(tp, ip, &free_list);
1804	if (error) {
1805		/*
1806		 * If we fail to free the inode, shut down.  The cancel
1807		 * might do that, we need to make sure.  Otherwise the
1808		 * inode might be lost for a long time or forever.
1809		 */
1810		if (!XFS_FORCED_SHUTDOWN(mp)) {
1811			xfs_notice(mp, "%s: xfs_ifree returned error %d",
1812				__func__, error);
1813			xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1814		}
1815		xfs_trans_cancel(tp);
1816		xfs_iunlock(ip, XFS_ILOCK_EXCL);
1817		return error;
1818	}
1819
1820	/*
1821	 * Credit the quota account(s). The inode is gone.
1822	 */
1823	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_ICOUNT, -1);
1824
1825	/*
1826	 * Just ignore errors at this point.  There is nothing we can do except
1827	 * to try to keep going. Make sure it's not a silent error.
1828	 */
1829	error = xfs_bmap_finish(&tp, &free_list, NULL);
1830	if (error) {
1831		xfs_notice(mp, "%s: xfs_bmap_finish returned error %d",
1832			__func__, error);
1833		xfs_bmap_cancel(&free_list);
1834	}
1835	error = xfs_trans_commit(tp);
1836	if (error)
1837		xfs_notice(mp, "%s: xfs_trans_commit returned error %d",
1838			__func__, error);
1839
1840	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1841	return 0;
1842}
1843
1844/*
1845 * xfs_inactive
1846 *
1847 * This is called when the vnode reference count for the vnode
1848 * goes to zero.  If the file has been unlinked, then it must
1849 * now be truncated.  Also, we clear all of the read-ahead state
1850 * kept for the inode here since the file is now closed.
1851 */
1852void
1853xfs_inactive(
1854	xfs_inode_t	*ip)
1855{
1856	struct xfs_mount	*mp;
1857	int			error;
1858	int			truncate = 0;
1859
1860	/*
1861	 * If the inode is already free, then there can be nothing
1862	 * to clean up here.
1863	 */
1864	if (VFS_I(ip)->i_mode == 0) {
1865		ASSERT(ip->i_df.if_real_bytes == 0);
1866		ASSERT(ip->i_df.if_broot_bytes == 0);
1867		return;
1868	}
1869
1870	mp = ip->i_mount;
 
1871
1872	/* If this is a read-only mount, don't do this (would generate I/O) */
1873	if (mp->m_flags & XFS_MOUNT_RDONLY)
1874		return;
1875
 
 
 
 
1876	if (VFS_I(ip)->i_nlink != 0) {
1877		/*
1878		 * force is true because we are evicting an inode from the
1879		 * cache. Post-eof blocks must be freed, lest we end up with
1880		 * broken free space accounting.
 
 
 
 
1881		 */
1882		if (xfs_can_free_eofblocks(ip, true))
1883			xfs_free_eofblocks(mp, ip, false);
1884
1885		return;
1886	}
1887
1888	if (S_ISREG(VFS_I(ip)->i_mode) &&
1889	    (ip->i_d.di_size != 0 || XFS_ISIZE(ip) != 0 ||
1890	     ip->i_d.di_nextents > 0 || ip->i_delayed_blks > 0))
1891		truncate = 1;
1892
1893	error = xfs_qm_dqattach(ip, 0);
1894	if (error)
1895		return;
1896
1897	if (S_ISLNK(VFS_I(ip)->i_mode))
1898		error = xfs_inactive_symlink(ip);
1899	else if (truncate)
1900		error = xfs_inactive_truncate(ip);
1901	if (error)
1902		return;
1903
1904	/*
1905	 * If there are attributes associated with the file then blow them away
1906	 * now.  The code calls a routine that recursively deconstructs the
1907	 * attribute fork. If also blows away the in-core attribute fork.
1908	 */
1909	if (XFS_IFORK_Q(ip)) {
1910		error = xfs_attr_inactive(ip);
1911		if (error)
1912			return;
1913	}
1914
1915	ASSERT(!ip->i_afp);
1916	ASSERT(ip->i_d.di_anextents == 0);
1917	ASSERT(ip->i_d.di_forkoff == 0);
1918
1919	/*
1920	 * Free the inode.
1921	 */
1922	error = xfs_inactive_ifree(ip);
1923	if (error)
1924		return;
1925
1926	/*
1927	 * Release the dquots held by inode, if any.
1928	 */
1929	xfs_qm_dqdetach(ip);
1930}
1931
1932/*
1933 * This is called when the inode's link count goes to 0 or we are creating a
1934 * tmpfile via O_TMPFILE. In the case of a tmpfile, @ignore_linkcount will be
1935 * set to true as the link count is dropped to zero by the VFS after we've
1936 * created the file successfully, so we have to add it to the unlinked list
1937 * while the link count is non-zero.
1938 *
1939 * We place the on-disk inode on a list in the AGI.  It will be pulled from this
1940 * list when the inode is freed.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1941 */
1942STATIC int
1943xfs_iunlink(
1944	struct xfs_trans *tp,
1945	struct xfs_inode *ip)
 
1946{
1947	xfs_mount_t	*mp = tp->t_mountp;
1948	xfs_agi_t	*agi;
1949	xfs_dinode_t	*dip;
1950	xfs_buf_t	*agibp;
1951	xfs_buf_t	*ibp;
1952	xfs_agino_t	agino;
1953	short		bucket_index;
1954	int		offset;
1955	int		error;
1956
1957	ASSERT(VFS_I(ip)->i_mode != 0);
 
 
 
 
1958
1959	/*
1960	 * Get the agi buffer first.  It ensures lock ordering
1961	 * on the list.
 
 
 
 
1962	 */
1963	error = xfs_read_agi(mp, tp, XFS_INO_TO_AGNO(mp, ip->i_ino), &agibp);
 
1964	if (error)
1965		return error;
1966	agi = XFS_BUF_TO_AGI(agibp);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1967
1968	/*
1969	 * Get the index into the agi hash table for the
1970	 * list this inode will go on.
 
1971	 */
1972	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
1973	ASSERT(agino != 0);
1974	bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
1975	ASSERT(agi->agi_unlinked[bucket_index]);
1976	ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino);
1977
1978	if (agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO)) {
1979		/*
1980		 * There is already another inode in the bucket we need
1981		 * to add ourselves to.  Add us at the front of the list.
1982		 * Here we put the head pointer into our next pointer,
1983		 * and then we fall through to point the head at us.
1984		 */
1985		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
1986				       0, 0);
1987		if (error)
1988			return error;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1989
1990		ASSERT(dip->di_next_unlinked == cpu_to_be32(NULLAGINO));
1991		dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
1992		offset = ip->i_imap.im_boffset +
1993			offsetof(xfs_dinode_t, di_next_unlinked);
1994
1995		/* need to recalc the inode CRC if appropriate */
1996		xfs_dinode_calc_crc(mp, dip);
1997
1998		xfs_trans_inode_buf(tp, ibp);
1999		xfs_trans_log_buf(tp, ibp, offset,
2000				  (offset + sizeof(xfs_agino_t) - 1));
2001		xfs_inobp_check(mp, ibp);
2002	}
2003
2004	/*
2005	 * Point the bucket head pointer at the inode being inserted.
2006	 */
2007	ASSERT(agino != 0);
2008	agi->agi_unlinked[bucket_index] = cpu_to_be32(agino);
2009	offset = offsetof(xfs_agi_t, agi_unlinked) +
2010		(sizeof(xfs_agino_t) * bucket_index);
2011	xfs_trans_buf_set_type(tp, agibp, XFS_BLFT_AGI_BUF);
2012	xfs_trans_log_buf(tp, agibp, offset,
2013			  (offset + sizeof(xfs_agino_t) - 1));
 
 
 
 
 
2014	return 0;
 
 
 
2015}
2016
2017/*
2018 * Pull the on-disk inode from the AGI unlinked list.
 
 
 
 
2019 */
2020STATIC int
2021xfs_iunlink_remove(
2022	xfs_trans_t	*tp,
2023	xfs_inode_t	*ip)
2024{
2025	xfs_ino_t	next_ino;
2026	xfs_mount_t	*mp;
2027	xfs_agi_t	*agi;
2028	xfs_dinode_t	*dip;
2029	xfs_buf_t	*agibp;
2030	xfs_buf_t	*ibp;
2031	xfs_agnumber_t	agno;
2032	xfs_agino_t	agino;
2033	xfs_agino_t	next_agino;
2034	xfs_buf_t	*last_ibp;
2035	xfs_dinode_t	*last_dip = NULL;
2036	short		bucket_index;
2037	int		offset, last_offset = 0;
2038	int		error;
2039
2040	mp = tp->t_mountp;
2041	agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
 
2042
2043	/*
2044	 * Get the agi buffer first.  It ensures lock ordering
2045	 * on the list.
2046	 */
2047	error = xfs_read_agi(mp, tp, agno, &agibp);
2048	if (error)
2049		return error;
2050
2051	agi = XFS_BUF_TO_AGI(agibp);
2052
2053	/*
2054	 * Get the index into the agi hash table for the
2055	 * list this inode will go on.
 
2056	 */
2057	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
2058	ASSERT(agino != 0);
2059	bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
2060	ASSERT(agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO));
2061	ASSERT(agi->agi_unlinked[bucket_index]);
2062
2063	if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
2064		/*
2065		 * We're at the head of the list.  Get the inode's on-disk
2066		 * buffer to see if there is anyone after us on the list.
2067		 * Only modify our next pointer if it is not already NULLAGINO.
2068		 * This saves us the overhead of dealing with the buffer when
2069		 * there is no need to change it.
2070		 */
2071		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2072				       0, 0);
2073		if (error) {
2074			xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
2075				__func__, error);
2076			return error;
2077		}
2078		next_agino = be32_to_cpu(dip->di_next_unlinked);
2079		ASSERT(next_agino != 0);
2080		if (next_agino != NULLAGINO) {
2081			dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2082			offset = ip->i_imap.im_boffset +
2083				offsetof(xfs_dinode_t, di_next_unlinked);
2084
2085			/* need to recalc the inode CRC if appropriate */
2086			xfs_dinode_calc_crc(mp, dip);
2087
2088			xfs_trans_inode_buf(tp, ibp);
2089			xfs_trans_log_buf(tp, ibp, offset,
2090					  (offset + sizeof(xfs_agino_t) - 1));
2091			xfs_inobp_check(mp, ibp);
2092		} else {
2093			xfs_trans_brelse(tp, ibp);
2094		}
2095		/*
2096		 * Point the bucket head pointer at the next inode.
 
2097		 */
2098		ASSERT(next_agino != 0);
2099		ASSERT(next_agino != agino);
2100		agi->agi_unlinked[bucket_index] = cpu_to_be32(next_agino);
2101		offset = offsetof(xfs_agi_t, agi_unlinked) +
2102			(sizeof(xfs_agino_t) * bucket_index);
2103		xfs_trans_buf_set_type(tp, agibp, XFS_BLFT_AGI_BUF);
2104		xfs_trans_log_buf(tp, agibp, offset,
2105				  (offset + sizeof(xfs_agino_t) - 1));
2106	} else {
2107		/*
2108		 * We need to search the list for the inode being freed.
 
2109		 */
2110		next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
2111		last_ibp = NULL;
2112		while (next_agino != agino) {
2113			struct xfs_imap	imap;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2114
2115			if (last_ibp)
2116				xfs_trans_brelse(tp, last_ibp);
2117
2118			imap.im_blkno = 0;
2119			next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2120
2121			error = xfs_imap(mp, tp, next_ino, &imap, 0);
2122			if (error) {
2123				xfs_warn(mp,
2124	"%s: xfs_imap returned error %d.",
2125					 __func__, error);
2126				return error;
2127			}
2128
2129			error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,
2130					       &last_ibp, 0, 0);
2131			if (error) {
2132				xfs_warn(mp,
2133	"%s: xfs_imap_to_bp returned error %d.",
2134					__func__, error);
2135				return error;
2136			}
2137
2138			last_offset = imap.im_boffset;
2139			next_agino = be32_to_cpu(last_dip->di_next_unlinked);
2140			ASSERT(next_agino != NULLAGINO);
2141			ASSERT(next_agino != 0);
2142		}
2143
2144		/*
2145		 * Now last_ibp points to the buffer previous to us on the
2146		 * unlinked list.  Pull us from the list.
2147		 */
2148		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2149				       0, 0);
2150		if (error) {
2151			xfs_warn(mp, "%s: xfs_imap_to_bp(2) returned error %d.",
2152				__func__, error);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2153			return error;
2154		}
2155		next_agino = be32_to_cpu(dip->di_next_unlinked);
2156		ASSERT(next_agino != 0);
2157		ASSERT(next_agino != agino);
2158		if (next_agino != NULLAGINO) {
2159			dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2160			offset = ip->i_imap.im_boffset +
2161				offsetof(xfs_dinode_t, di_next_unlinked);
2162
2163			/* need to recalc the inode CRC if appropriate */
2164			xfs_dinode_calc_crc(mp, dip);
2165
2166			xfs_trans_inode_buf(tp, ibp);
2167			xfs_trans_log_buf(tp, ibp, offset,
2168					  (offset + sizeof(xfs_agino_t) - 1));
2169			xfs_inobp_check(mp, ibp);
2170		} else {
2171			xfs_trans_brelse(tp, ibp);
2172		}
2173		/*
2174		 * Point the previous inode on the list to the next inode.
 
2175		 */
2176		last_dip->di_next_unlinked = cpu_to_be32(next_agino);
2177		ASSERT(next_agino != 0);
2178		offset = last_offset + offsetof(xfs_dinode_t, di_next_unlinked);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2179
2180		/* need to recalc the inode CRC if appropriate */
2181		xfs_dinode_calc_crc(mp, last_dip);
 
2182
2183		xfs_trans_inode_buf(tp, last_ibp);
2184		xfs_trans_log_buf(tp, last_ibp, offset,
2185				  (offset + sizeof(xfs_agino_t) - 1));
2186		xfs_inobp_check(mp, last_ibp);
 
 
 
 
 
 
 
2187	}
2188	return 0;
 
 
 
 
2189}
2190
2191/*
2192 * A big issue when freeing the inode cluster is that we _cannot_ skip any
2193 * inodes that are in memory - they all must be marked stale and attached to
2194 * the cluster buffer.
2195 */
2196STATIC int
2197xfs_ifree_cluster(
2198	xfs_inode_t		*free_ip,
2199	xfs_trans_t		*tp,
2200	struct xfs_icluster	*xic)
2201{
2202	xfs_mount_t		*mp = free_ip->i_mount;
2203	int			blks_per_cluster;
2204	int			inodes_per_cluster;
2205	int			nbufs;
2206	int			i, j;
2207	int			ioffset;
2208	xfs_daddr_t		blkno;
2209	xfs_buf_t		*bp;
2210	xfs_inode_t		*ip;
2211	xfs_inode_log_item_t	*iip;
2212	xfs_log_item_t		*lip;
2213	struct xfs_perag	*pag;
 
2214	xfs_ino_t		inum;
2215
2216	inum = xic->first_ino;
2217	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, inum));
2218	blks_per_cluster = xfs_icluster_size_fsb(mp);
2219	inodes_per_cluster = blks_per_cluster << mp->m_sb.sb_inopblog;
2220	nbufs = mp->m_ialloc_blks / blks_per_cluster;
2221
2222	for (j = 0; j < nbufs; j++, inum += inodes_per_cluster) {
2223		/*
2224		 * The allocation bitmap tells us which inodes of the chunk were
2225		 * physically allocated. Skip the cluster if an inode falls into
2226		 * a sparse region.
2227		 */
2228		ioffset = inum - xic->first_ino;
2229		if ((xic->alloc & XFS_INOBT_MASK(ioffset)) == 0) {
2230			ASSERT(do_mod(ioffset, inodes_per_cluster) == 0);
2231			continue;
2232		}
2233
2234		blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
2235					 XFS_INO_TO_AGBNO(mp, inum));
2236
2237		/*
2238		 * We obtain and lock the backing buffer first in the process
2239		 * here, as we have to ensure that any dirty inode that we
2240		 * can't get the flush lock on is attached to the buffer.
2241		 * If we scan the in-memory inodes first, then buffer IO can
2242		 * complete before we get a lock on it, and hence we may fail
2243		 * to mark all the active inodes on the buffer stale.
2244		 */
2245		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
2246					mp->m_bsize * blks_per_cluster,
2247					XBF_UNMAPPED);
2248
2249		if (!bp)
2250			return -ENOMEM;
2251
2252		/*
2253		 * This buffer may not have been correctly initialised as we
2254		 * didn't read it from disk. That's not important because we are
2255		 * only using to mark the buffer as stale in the log, and to
2256		 * attach stale cached inodes on it. That means it will never be
2257		 * dispatched for IO. If it is, we want to know about it, and we
2258		 * want it to fail. We can acheive this by adding a write
2259		 * verifier to the buffer.
2260		 */
2261		 bp->b_ops = &xfs_inode_buf_ops;
2262
2263		/*
2264		 * Walk the inodes already attached to the buffer and mark them
2265		 * stale. These will all have the flush locks held, so an
2266		 * in-memory inode walk can't lock them. By marking them all
2267		 * stale first, we will not attempt to lock them in the loop
2268		 * below as the XFS_ISTALE flag will be set.
2269		 */
2270		lip = bp->b_fspriv;
2271		while (lip) {
2272			if (lip->li_type == XFS_LI_INODE) {
2273				iip = (xfs_inode_log_item_t *)lip;
2274				ASSERT(iip->ili_logged == 1);
2275				lip->li_cb = xfs_istale_done;
2276				xfs_trans_ail_copy_lsn(mp->m_ail,
2277							&iip->ili_flush_lsn,
2278							&iip->ili_item.li_lsn);
2279				xfs_iflags_set(iip->ili_inode, XFS_ISTALE);
2280			}
2281			lip = lip->li_bio_list;
2282		}
2283
2284
2285		/*
2286		 * For each inode in memory attempt to add it to the inode
2287		 * buffer and set it up for being staled on buffer IO
2288		 * completion.  This is safe as we've locked out tail pushing
2289		 * and flushing by locking the buffer.
2290		 *
2291		 * We have already marked every inode that was part of a
2292		 * transaction stale above, which means there is no point in
2293		 * even trying to lock them.
2294		 */
2295		for (i = 0; i < inodes_per_cluster; i++) {
2296retry:
2297			rcu_read_lock();
2298			ip = radix_tree_lookup(&pag->pag_ici_root,
2299					XFS_INO_TO_AGINO(mp, (inum + i)));
2300
2301			/* Inode not in memory, nothing to do */
2302			if (!ip) {
2303				rcu_read_unlock();
2304				continue;
2305			}
2306
2307			/*
2308			 * because this is an RCU protected lookup, we could
2309			 * find a recently freed or even reallocated inode
2310			 * during the lookup. We need to check under the
2311			 * i_flags_lock for a valid inode here. Skip it if it
2312			 * is not valid, the wrong inode or stale.
2313			 */
2314			spin_lock(&ip->i_flags_lock);
2315			if (ip->i_ino != inum + i ||
2316			    __xfs_iflags_test(ip, XFS_ISTALE)) {
2317				spin_unlock(&ip->i_flags_lock);
2318				rcu_read_unlock();
2319				continue;
2320			}
2321			spin_unlock(&ip->i_flags_lock);
2322
2323			/*
2324			 * Don't try to lock/unlock the current inode, but we
2325			 * _cannot_ skip the other inodes that we did not find
2326			 * in the list attached to the buffer and are not
2327			 * already marked stale. If we can't lock it, back off
2328			 * and retry.
2329			 */
2330			if (ip != free_ip &&
2331			    !xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
2332				rcu_read_unlock();
2333				delay(1);
2334				goto retry;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2335			}
2336			rcu_read_unlock();
2337
2338			xfs_iflock(ip);
2339			xfs_iflags_set(ip, XFS_ISTALE);
2340
2341			/*
2342			 * we don't need to attach clean inodes or those only
2343			 * with unlogged changes (which we throw away, anyway).
2344			 */
2345			iip = ip->i_itemp;
2346			if (!iip || xfs_inode_clean(ip)) {
2347				ASSERT(ip != free_ip);
2348				xfs_ifunlock(ip);
2349				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2350				continue;
2351			}
2352
2353			iip->ili_last_fields = iip->ili_fields;
2354			iip->ili_fields = 0;
2355			iip->ili_fsync_fields = 0;
2356			iip->ili_logged = 1;
2357			xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
2358						&iip->ili_item.li_lsn);
2359
2360			xfs_buf_attach_iodone(bp, xfs_istale_done,
2361						  &iip->ili_item);
2362
2363			if (ip != free_ip)
2364				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2365		}
2366
2367		xfs_trans_stale_inode_buf(tp, bp);
2368		xfs_trans_binval(tp, bp);
2369	}
2370
2371	xfs_perag_put(pag);
2372	return 0;
2373}
2374
2375/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2376 * This is called to return an inode to the inode free list.
2377 * The inode should already be truncated to 0 length and have
2378 * no pages associated with it.  This routine also assumes that
2379 * the inode is already a part of the transaction.
2380 *
2381 * The on-disk copy of the inode will have been added to the list
2382 * of unlinked inodes in the AGI. We need to remove the inode from
2383 * that list atomically with respect to freeing it here.
2384 */
2385int
2386xfs_ifree(
2387	xfs_trans_t	*tp,
2388	xfs_inode_t	*ip,
2389	xfs_bmap_free_t	*flist)
2390{
2391	int			error;
2392	struct xfs_icluster	xic = { 0 };
2393
2394	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
2395	ASSERT(VFS_I(ip)->i_nlink == 0);
2396	ASSERT(ip->i_d.di_nextents == 0);
2397	ASSERT(ip->i_d.di_anextents == 0);
2398	ASSERT(ip->i_d.di_size == 0 || !S_ISREG(VFS_I(ip)->i_mode));
2399	ASSERT(ip->i_d.di_nblocks == 0);
2400
2401	/*
2402	 * Pull the on-disk inode from the AGI unlinked list.
2403	 */
2404	error = xfs_iunlink_remove(tp, ip);
2405	if (error)
2406		return error;
2407
2408	error = xfs_difree(tp, ip->i_ino, flist, &xic);
2409	if (error)
2410		return error;
2411
 
 
 
2412	VFS_I(ip)->i_mode = 0;		/* mark incore inode as free */
2413	ip->i_d.di_flags = 0;
 
2414	ip->i_d.di_dmevmask = 0;
2415	ip->i_d.di_forkoff = 0;		/* mark the attr fork not in use */
2416	ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
2417	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
 
 
 
 
2418	/*
2419	 * Bump the generation count so no one will be confused
2420	 * by reincarnations of this inode.
2421	 */
2422	VFS_I(ip)->i_generation++;
2423	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2424
2425	if (xic.deleted)
2426		error = xfs_ifree_cluster(ip, tp, &xic);
2427
2428	return error;
2429}
2430
2431/*
2432 * This is called to unpin an inode.  The caller must have the inode locked
2433 * in at least shared mode so that the buffer cannot be subsequently pinned
2434 * once someone is waiting for it to be unpinned.
2435 */
2436static void
2437xfs_iunpin(
2438	struct xfs_inode	*ip)
2439{
2440	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
2441
2442	trace_xfs_inode_unpin_nowait(ip, _RET_IP_);
2443
2444	/* Give the log a push to start the unpinning I/O */
2445	xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0);
2446
2447}
2448
2449static void
2450__xfs_iunpin_wait(
2451	struct xfs_inode	*ip)
2452{
2453	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IPINNED_BIT);
2454	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IPINNED_BIT);
2455
2456	xfs_iunpin(ip);
2457
2458	do {
2459		prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
2460		if (xfs_ipincount(ip))
2461			io_schedule();
2462	} while (xfs_ipincount(ip));
2463	finish_wait(wq, &wait.wait);
2464}
2465
2466void
2467xfs_iunpin_wait(
2468	struct xfs_inode	*ip)
2469{
2470	if (xfs_ipincount(ip))
2471		__xfs_iunpin_wait(ip);
2472}
2473
2474/*
2475 * Removing an inode from the namespace involves removing the directory entry
2476 * and dropping the link count on the inode. Removing the directory entry can
2477 * result in locking an AGF (directory blocks were freed) and removing a link
2478 * count can result in placing the inode on an unlinked list which results in
2479 * locking an AGI.
2480 *
2481 * The big problem here is that we have an ordering constraint on AGF and AGI
2482 * locking - inode allocation locks the AGI, then can allocate a new extent for
2483 * new inodes, locking the AGF after the AGI. Similarly, freeing the inode
2484 * removes the inode from the unlinked list, requiring that we lock the AGI
2485 * first, and then freeing the inode can result in an inode chunk being freed
2486 * and hence freeing disk space requiring that we lock an AGF.
2487 *
2488 * Hence the ordering that is imposed by other parts of the code is AGI before
2489 * AGF. This means we cannot remove the directory entry before we drop the inode
2490 * reference count and put it on the unlinked list as this results in a lock
2491 * order of AGF then AGI, and this can deadlock against inode allocation and
2492 * freeing. Therefore we must drop the link counts before we remove the
2493 * directory entry.
2494 *
2495 * This is still safe from a transactional point of view - it is not until we
2496 * get to xfs_bmap_finish() that we have the possibility of multiple
2497 * transactions in this operation. Hence as long as we remove the directory
2498 * entry and drop the link count in the first transaction of the remove
2499 * operation, there are no transactional constraints on the ordering here.
2500 */
2501int
2502xfs_remove(
2503	xfs_inode_t             *dp,
2504	struct xfs_name		*name,
2505	xfs_inode_t		*ip)
2506{
2507	xfs_mount_t		*mp = dp->i_mount;
2508	xfs_trans_t             *tp = NULL;
2509	int			is_dir = S_ISDIR(VFS_I(ip)->i_mode);
2510	int                     error = 0;
2511	xfs_bmap_free_t         free_list;
2512	xfs_fsblock_t           first_block;
2513	uint			resblks;
2514
2515	trace_xfs_remove(dp, name);
2516
2517	if (XFS_FORCED_SHUTDOWN(mp))
2518		return -EIO;
2519
2520	error = xfs_qm_dqattach(dp, 0);
2521	if (error)
2522		goto std_return;
2523
2524	error = xfs_qm_dqattach(ip, 0);
2525	if (error)
2526		goto std_return;
2527
2528	if (is_dir)
2529		tp = xfs_trans_alloc(mp, XFS_TRANS_RMDIR);
2530	else
2531		tp = xfs_trans_alloc(mp, XFS_TRANS_REMOVE);
2532
2533	/*
2534	 * We try to get the real space reservation first,
2535	 * allowing for directory btree deletion(s) implying
2536	 * possible bmap insert(s).  If we can't get the space
2537	 * reservation then we use 0 instead, and avoid the bmap
2538	 * btree insert(s) in the directory code by, if the bmap
2539	 * insert tries to happen, instead trimming the LAST
2540	 * block from the directory.
2541	 */
2542	resblks = XFS_REMOVE_SPACE_RES(mp);
2543	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_remove, resblks, 0);
2544	if (error == -ENOSPC) {
2545		resblks = 0;
2546		error = xfs_trans_reserve(tp, &M_RES(mp)->tr_remove, 0, 0);
 
2547	}
2548	if (error) {
2549		ASSERT(error != -ENOSPC);
2550		goto out_trans_cancel;
2551	}
2552
2553	xfs_ilock(dp, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
2554	xfs_lock_two_inodes(dp, ip, XFS_ILOCK_EXCL);
2555
2556	xfs_trans_ijoin(tp, dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
2557	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
2558
2559	/*
2560	 * If we're removing a directory perform some additional validation.
2561	 */
2562	if (is_dir) {
2563		ASSERT(VFS_I(ip)->i_nlink >= 2);
2564		if (VFS_I(ip)->i_nlink != 2) {
2565			error = -ENOTEMPTY;
2566			goto out_trans_cancel;
2567		}
2568		if (!xfs_dir_isempty(ip)) {
2569			error = -ENOTEMPTY;
2570			goto out_trans_cancel;
2571		}
2572
2573		/* Drop the link from ip's "..".  */
2574		error = xfs_droplink(tp, dp);
2575		if (error)
2576			goto out_trans_cancel;
2577
2578		/* Drop the "." link from ip to self.  */
2579		error = xfs_droplink(tp, ip);
2580		if (error)
2581			goto out_trans_cancel;
2582	} else {
2583		/*
2584		 * When removing a non-directory we need to log the parent
2585		 * inode here.  For a directory this is done implicitly
2586		 * by the xfs_droplink call for the ".." entry.
2587		 */
2588		xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
2589	}
2590	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2591
2592	/* Drop the link from dp to ip. */
2593	error = xfs_droplink(tp, ip);
2594	if (error)
2595		goto out_trans_cancel;
2596
2597	xfs_bmap_init(&free_list, &first_block);
2598	error = xfs_dir_removename(tp, dp, name, ip->i_ino,
2599					&first_block, &free_list, resblks);
2600	if (error) {
2601		ASSERT(error != -ENOENT);
2602		goto out_bmap_cancel;
2603	}
2604
2605	/*
2606	 * If this is a synchronous mount, make sure that the
2607	 * remove transaction goes to disk before returning to
2608	 * the user.
2609	 */
2610	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2611		xfs_trans_set_sync(tp);
2612
2613	error = xfs_bmap_finish(&tp, &free_list, NULL);
2614	if (error)
2615		goto out_bmap_cancel;
2616
2617	error = xfs_trans_commit(tp);
2618	if (error)
2619		goto std_return;
2620
2621	if (is_dir && xfs_inode_is_filestream(ip))
2622		xfs_filestream_deassociate(ip);
2623
2624	return 0;
2625
2626 out_bmap_cancel:
2627	xfs_bmap_cancel(&free_list);
2628 out_trans_cancel:
2629	xfs_trans_cancel(tp);
2630 std_return:
2631	return error;
2632}
2633
2634/*
2635 * Enter all inodes for a rename transaction into a sorted array.
2636 */
2637#define __XFS_SORT_INODES	5
2638STATIC void
2639xfs_sort_for_rename(
2640	struct xfs_inode	*dp1,	/* in: old (source) directory inode */
2641	struct xfs_inode	*dp2,	/* in: new (target) directory inode */
2642	struct xfs_inode	*ip1,	/* in: inode of old entry */
2643	struct xfs_inode	*ip2,	/* in: inode of new entry */
2644	struct xfs_inode	*wip,	/* in: whiteout inode */
2645	struct xfs_inode	**i_tab,/* out: sorted array of inodes */
2646	int			*num_inodes)  /* in/out: inodes in array */
2647{
2648	int			i, j;
2649
2650	ASSERT(*num_inodes == __XFS_SORT_INODES);
2651	memset(i_tab, 0, *num_inodes * sizeof(struct xfs_inode *));
2652
2653	/*
2654	 * i_tab contains a list of pointers to inodes.  We initialize
2655	 * the table here & we'll sort it.  We will then use it to
2656	 * order the acquisition of the inode locks.
2657	 *
2658	 * Note that the table may contain duplicates.  e.g., dp1 == dp2.
2659	 */
2660	i = 0;
2661	i_tab[i++] = dp1;
2662	i_tab[i++] = dp2;
2663	i_tab[i++] = ip1;
2664	if (ip2)
2665		i_tab[i++] = ip2;
2666	if (wip)
2667		i_tab[i++] = wip;
2668	*num_inodes = i;
2669
2670	/*
2671	 * Sort the elements via bubble sort.  (Remember, there are at
2672	 * most 5 elements to sort, so this is adequate.)
2673	 */
2674	for (i = 0; i < *num_inodes; i++) {
2675		for (j = 1; j < *num_inodes; j++) {
2676			if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
2677				struct xfs_inode *temp = i_tab[j];
2678				i_tab[j] = i_tab[j-1];
2679				i_tab[j-1] = temp;
2680			}
2681		}
2682	}
2683}
2684
2685static int
2686xfs_finish_rename(
2687	struct xfs_trans	*tp,
2688	struct xfs_bmap_free	*free_list)
2689{
2690	int			error;
2691
2692	/*
2693	 * If this is a synchronous mount, make sure that the rename transaction
2694	 * goes to disk before returning to the user.
2695	 */
2696	if (tp->t_mountp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2697		xfs_trans_set_sync(tp);
2698
2699	error = xfs_bmap_finish(&tp, free_list, NULL);
2700	if (error) {
2701		xfs_bmap_cancel(free_list);
2702		xfs_trans_cancel(tp);
2703		return error;
2704	}
2705
2706	return xfs_trans_commit(tp);
2707}
2708
2709/*
2710 * xfs_cross_rename()
2711 *
2712 * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall
2713 */
2714STATIC int
2715xfs_cross_rename(
2716	struct xfs_trans	*tp,
2717	struct xfs_inode	*dp1,
2718	struct xfs_name		*name1,
2719	struct xfs_inode	*ip1,
2720	struct xfs_inode	*dp2,
2721	struct xfs_name		*name2,
2722	struct xfs_inode	*ip2,
2723	struct xfs_bmap_free	*free_list,
2724	xfs_fsblock_t		*first_block,
2725	int			spaceres)
2726{
2727	int		error = 0;
2728	int		ip1_flags = 0;
2729	int		ip2_flags = 0;
2730	int		dp2_flags = 0;
2731
2732	/* Swap inode number for dirent in first parent */
2733	error = xfs_dir_replace(tp, dp1, name1,
2734				ip2->i_ino,
2735				first_block, free_list, spaceres);
2736	if (error)
2737		goto out_trans_abort;
2738
2739	/* Swap inode number for dirent in second parent */
2740	error = xfs_dir_replace(tp, dp2, name2,
2741				ip1->i_ino,
2742				first_block, free_list, spaceres);
2743	if (error)
2744		goto out_trans_abort;
2745
2746	/*
2747	 * If we're renaming one or more directories across different parents,
2748	 * update the respective ".." entries (and link counts) to match the new
2749	 * parents.
2750	 */
2751	if (dp1 != dp2) {
2752		dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2753
2754		if (S_ISDIR(VFS_I(ip2)->i_mode)) {
2755			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
2756						dp1->i_ino, first_block,
2757						free_list, spaceres);
2758			if (error)
2759				goto out_trans_abort;
2760
2761			/* transfer ip2 ".." reference to dp1 */
2762			if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
2763				error = xfs_droplink(tp, dp2);
2764				if (error)
2765					goto out_trans_abort;
2766				error = xfs_bumplink(tp, dp1);
2767				if (error)
2768					goto out_trans_abort;
2769			}
2770
2771			/*
2772			 * Although ip1 isn't changed here, userspace needs
2773			 * to be warned about the change, so that applications
2774			 * relying on it (like backup ones), will properly
2775			 * notify the change
2776			 */
2777			ip1_flags |= XFS_ICHGTIME_CHG;
2778			ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2779		}
2780
2781		if (S_ISDIR(VFS_I(ip1)->i_mode)) {
2782			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
2783						dp2->i_ino, first_block,
2784						free_list, spaceres);
2785			if (error)
2786				goto out_trans_abort;
2787
2788			/* transfer ip1 ".." reference to dp2 */
2789			if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
2790				error = xfs_droplink(tp, dp1);
2791				if (error)
2792					goto out_trans_abort;
2793				error = xfs_bumplink(tp, dp2);
2794				if (error)
2795					goto out_trans_abort;
2796			}
2797
2798			/*
2799			 * Although ip2 isn't changed here, userspace needs
2800			 * to be warned about the change, so that applications
2801			 * relying on it (like backup ones), will properly
2802			 * notify the change
2803			 */
2804			ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2805			ip2_flags |= XFS_ICHGTIME_CHG;
2806		}
2807	}
2808
2809	if (ip1_flags) {
2810		xfs_trans_ichgtime(tp, ip1, ip1_flags);
2811		xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
2812	}
2813	if (ip2_flags) {
2814		xfs_trans_ichgtime(tp, ip2, ip2_flags);
2815		xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
2816	}
2817	if (dp2_flags) {
2818		xfs_trans_ichgtime(tp, dp2, dp2_flags);
2819		xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
2820	}
2821	xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2822	xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
2823	return xfs_finish_rename(tp, free_list);
2824
2825out_trans_abort:
2826	xfs_bmap_cancel(free_list);
2827	xfs_trans_cancel(tp);
2828	return error;
2829}
2830
2831/*
2832 * xfs_rename_alloc_whiteout()
2833 *
2834 * Return a referenced, unlinked, unlocked inode that that can be used as a
2835 * whiteout in a rename transaction. We use a tmpfile inode here so that if we
2836 * crash between allocating the inode and linking it into the rename transaction
2837 * recovery will free the inode and we won't leak it.
2838 */
2839static int
2840xfs_rename_alloc_whiteout(
2841	struct xfs_inode	*dp,
2842	struct xfs_inode	**wip)
2843{
2844	struct xfs_inode	*tmpfile;
2845	int			error;
2846
2847	error = xfs_create_tmpfile(dp, NULL, S_IFCHR | WHITEOUT_MODE, &tmpfile);
2848	if (error)
2849		return error;
2850
2851	/*
2852	 * Prepare the tmpfile inode as if it were created through the VFS.
2853	 * Otherwise, the link increment paths will complain about nlink 0->1.
2854	 * Drop the link count as done by d_tmpfile(), complete the inode setup
2855	 * and flag it as linkable.
2856	 */
2857	drop_nlink(VFS_I(tmpfile));
2858	xfs_finish_inode_setup(tmpfile);
2859	VFS_I(tmpfile)->i_state |= I_LINKABLE;
2860
2861	*wip = tmpfile;
2862	return 0;
2863}
2864
2865/*
2866 * xfs_rename
2867 */
2868int
2869xfs_rename(
2870	struct xfs_inode	*src_dp,
2871	struct xfs_name		*src_name,
2872	struct xfs_inode	*src_ip,
2873	struct xfs_inode	*target_dp,
2874	struct xfs_name		*target_name,
2875	struct xfs_inode	*target_ip,
2876	unsigned int		flags)
2877{
2878	struct xfs_mount	*mp = src_dp->i_mount;
2879	struct xfs_trans	*tp;
2880	struct xfs_bmap_free	free_list;
2881	xfs_fsblock_t		first_block;
2882	struct xfs_inode	*wip = NULL;		/* whiteout inode */
2883	struct xfs_inode	*inodes[__XFS_SORT_INODES];
2884	int			num_inodes = __XFS_SORT_INODES;
2885	bool			new_parent = (src_dp != target_dp);
2886	bool			src_is_directory = S_ISDIR(VFS_I(src_ip)->i_mode);
2887	int			spaceres;
2888	int			error;
2889
2890	trace_xfs_rename(src_dp, target_dp, src_name, target_name);
2891
2892	if ((flags & RENAME_EXCHANGE) && !target_ip)
2893		return -EINVAL;
2894
2895	/*
2896	 * If we are doing a whiteout operation, allocate the whiteout inode
2897	 * we will be placing at the target and ensure the type is set
2898	 * appropriately.
2899	 */
2900	if (flags & RENAME_WHITEOUT) {
2901		ASSERT(!(flags & (RENAME_NOREPLACE | RENAME_EXCHANGE)));
2902		error = xfs_rename_alloc_whiteout(target_dp, &wip);
2903		if (error)
2904			return error;
2905
2906		/* setup target dirent info as whiteout */
2907		src_name->type = XFS_DIR3_FT_CHRDEV;
2908	}
2909
2910	xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip, wip,
2911				inodes, &num_inodes);
2912
2913	tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME);
2914	spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
2915	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_rename, spaceres, 0);
2916	if (error == -ENOSPC) {
2917		spaceres = 0;
2918		error = xfs_trans_reserve(tp, &M_RES(mp)->tr_rename, 0, 0);
 
2919	}
2920	if (error)
2921		goto out_trans_cancel;
2922
2923	/*
2924	 * Attach the dquots to the inodes
2925	 */
2926	error = xfs_qm_vop_rename_dqattach(inodes);
2927	if (error)
2928		goto out_trans_cancel;
2929
2930	/*
2931	 * Lock all the participating inodes. Depending upon whether
2932	 * the target_name exists in the target directory, and
2933	 * whether the target directory is the same as the source
2934	 * directory, we can lock from 2 to 4 inodes.
2935	 */
2936	if (!new_parent)
2937		xfs_ilock(src_dp, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
2938	else
2939		xfs_lock_two_inodes(src_dp, target_dp,
2940				    XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
2941
2942	xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
2943
2944	/*
2945	 * Join all the inodes to the transaction. From this point on,
2946	 * we can rely on either trans_commit or trans_cancel to unlock
2947	 * them.
2948	 */
2949	xfs_trans_ijoin(tp, src_dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
2950	if (new_parent)
2951		xfs_trans_ijoin(tp, target_dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
2952	xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
2953	if (target_ip)
2954		xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
2955	if (wip)
2956		xfs_trans_ijoin(tp, wip, XFS_ILOCK_EXCL);
2957
2958	/*
2959	 * If we are using project inheritance, we only allow renames
2960	 * into our tree when the project IDs are the same; else the
2961	 * tree quota mechanism would be circumvented.
2962	 */
2963	if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
2964		     (xfs_get_projid(target_dp) != xfs_get_projid(src_ip)))) {
2965		error = -EXDEV;
2966		goto out_trans_cancel;
2967	}
2968
2969	xfs_bmap_init(&free_list, &first_block);
2970
2971	/* RENAME_EXCHANGE is unique from here on. */
2972	if (flags & RENAME_EXCHANGE)
2973		return xfs_cross_rename(tp, src_dp, src_name, src_ip,
2974					target_dp, target_name, target_ip,
2975					&free_list, &first_block, spaceres);
2976
2977	/*
2978	 * Set up the target.
 
2979	 */
2980	if (target_ip == NULL) {
2981		/*
2982		 * If there's no space reservation, check the entry will
2983		 * fit before actually inserting it.
2984		 */
2985		if (!spaceres) {
2986			error = xfs_dir_canenter(tp, target_dp, target_name);
2987			if (error)
2988				goto out_trans_cancel;
2989		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2990		/*
2991		 * If target does not exist and the rename crosses
2992		 * directories, adjust the target directory link count
2993		 * to account for the ".." reference from the new entry.
2994		 */
2995		error = xfs_dir_createname(tp, target_dp, target_name,
2996						src_ip->i_ino, &first_block,
2997						&free_list, spaceres);
2998		if (error)
2999			goto out_bmap_cancel;
3000
3001		xfs_trans_ichgtime(tp, target_dp,
3002					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3003
3004		if (new_parent && src_is_directory) {
3005			error = xfs_bumplink(tp, target_dp);
3006			if (error)
3007				goto out_bmap_cancel;
3008		}
3009	} else { /* target_ip != NULL */
3010		/*
3011		 * If target exists and it's a directory, check that both
3012		 * target and source are directories and that target can be
3013		 * destroyed, or that neither is a directory.
3014		 */
3015		if (S_ISDIR(VFS_I(target_ip)->i_mode)) {
3016			/*
3017			 * Make sure target dir is empty.
3018			 */
3019			if (!(xfs_dir_isempty(target_ip)) ||
3020			    (VFS_I(target_ip)->i_nlink > 2)) {
3021				error = -EEXIST;
3022				goto out_trans_cancel;
3023			}
3024		}
3025
3026		/*
3027		 * Link the source inode under the target name.
3028		 * If the source inode is a directory and we are moving
3029		 * it across directories, its ".." entry will be
3030		 * inconsistent until we replace that down below.
3031		 *
3032		 * In case there is already an entry with the same
3033		 * name at the destination directory, remove it first.
3034		 */
3035		error = xfs_dir_replace(tp, target_dp, target_name,
3036					src_ip->i_ino,
3037					&first_block, &free_list, spaceres);
3038		if (error)
3039			goto out_bmap_cancel;
3040
3041		xfs_trans_ichgtime(tp, target_dp,
3042					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3043
3044		/*
3045		 * Decrement the link count on the target since the target
3046		 * dir no longer points to it.
3047		 */
3048		error = xfs_droplink(tp, target_ip);
3049		if (error)
3050			goto out_bmap_cancel;
3051
3052		if (src_is_directory) {
3053			/*
3054			 * Drop the link from the old "." entry.
3055			 */
3056			error = xfs_droplink(tp, target_ip);
3057			if (error)
3058				goto out_bmap_cancel;
3059		}
3060	} /* target_ip != NULL */
3061
3062	/*
3063	 * Remove the source.
3064	 */
3065	if (new_parent && src_is_directory) {
3066		/*
3067		 * Rewrite the ".." entry to point to the new
3068		 * directory.
3069		 */
3070		error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
3071					target_dp->i_ino,
3072					&first_block, &free_list, spaceres);
3073		ASSERT(error != -EEXIST);
3074		if (error)
3075			goto out_bmap_cancel;
3076	}
3077
3078	/*
3079	 * We always want to hit the ctime on the source inode.
3080	 *
3081	 * This isn't strictly required by the standards since the source
3082	 * inode isn't really being changed, but old unix file systems did
3083	 * it and some incremental backup programs won't work without it.
3084	 */
3085	xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
3086	xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
3087
3088	/*
3089	 * Adjust the link count on src_dp.  This is necessary when
3090	 * renaming a directory, either within one parent when
3091	 * the target existed, or across two parent directories.
3092	 */
3093	if (src_is_directory && (new_parent || target_ip != NULL)) {
3094
3095		/*
3096		 * Decrement link count on src_directory since the
3097		 * entry that's moved no longer points to it.
3098		 */
3099		error = xfs_droplink(tp, src_dp);
3100		if (error)
3101			goto out_bmap_cancel;
3102	}
3103
3104	/*
3105	 * For whiteouts, we only need to update the source dirent with the
3106	 * inode number of the whiteout inode rather than removing it
3107	 * altogether.
3108	 */
3109	if (wip) {
3110		error = xfs_dir_replace(tp, src_dp, src_name, wip->i_ino,
3111					&first_block, &free_list, spaceres);
3112	} else
3113		error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
3114					   &first_block, &free_list, spaceres);
3115	if (error)
3116		goto out_bmap_cancel;
3117
3118	/*
3119	 * For whiteouts, we need to bump the link count on the whiteout inode.
3120	 * This means that failures all the way up to this point leave the inode
3121	 * on the unlinked list and so cleanup is a simple matter of dropping
3122	 * the remaining reference to it. If we fail here after bumping the link
3123	 * count, we're shutting down the filesystem so we'll never see the
3124	 * intermediate state on disk.
3125	 */
3126	if (wip) {
3127		ASSERT(VFS_I(wip)->i_nlink == 0);
3128		error = xfs_bumplink(tp, wip);
3129		if (error)
3130			goto out_bmap_cancel;
3131		error = xfs_iunlink_remove(tp, wip);
3132		if (error)
3133			goto out_bmap_cancel;
3134		xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE);
3135
3136		/*
3137		 * Now we have a real link, clear the "I'm a tmpfile" state
3138		 * flag from the inode so it doesn't accidentally get misused in
3139		 * future.
3140		 */
3141		VFS_I(wip)->i_state &= ~I_LINKABLE;
3142	}
3143
3144	xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3145	xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
3146	if (new_parent)
3147		xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
3148
3149	error = xfs_finish_rename(tp, &free_list);
3150	if (wip)
3151		IRELE(wip);
3152	return error;
3153
3154out_bmap_cancel:
3155	xfs_bmap_cancel(&free_list);
3156out_trans_cancel:
3157	xfs_trans_cancel(tp);
 
3158	if (wip)
3159		IRELE(wip);
3160	return error;
3161}
3162
3163STATIC int
3164xfs_iflush_cluster(
3165	xfs_inode_t	*ip,
3166	xfs_buf_t	*bp)
3167{
3168	xfs_mount_t		*mp = ip->i_mount;
3169	struct xfs_perag	*pag;
3170	unsigned long		first_index, mask;
3171	unsigned long		inodes_per_cluster;
3172	int			ilist_size;
3173	xfs_inode_t		**ilist;
3174	xfs_inode_t		*iq;
3175	int			nr_found;
3176	int			clcount = 0;
3177	int			bufwasdelwri;
3178	int			i;
3179
3180	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
3181
3182	inodes_per_cluster = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;
3183	ilist_size = inodes_per_cluster * sizeof(xfs_inode_t *);
3184	ilist = kmem_alloc(ilist_size, KM_MAYFAIL|KM_NOFS);
3185	if (!ilist)
3186		goto out_put;
3187
3188	mask = ~(((mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog)) - 1);
3189	first_index = XFS_INO_TO_AGINO(mp, ip->i_ino) & mask;
3190	rcu_read_lock();
3191	/* really need a gang lookup range call here */
3192	nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void**)ilist,
3193					first_index, inodes_per_cluster);
3194	if (nr_found == 0)
3195		goto out_free;
3196
3197	for (i = 0; i < nr_found; i++) {
3198		iq = ilist[i];
3199		if (iq == ip)
3200			continue;
3201
3202		/*
3203		 * because this is an RCU protected lookup, we could find a
3204		 * recently freed or even reallocated inode during the lookup.
3205		 * We need to check under the i_flags_lock for a valid inode
3206		 * here. Skip it if it is not valid or the wrong inode.
3207		 */
3208		spin_lock(&ip->i_flags_lock);
3209		if (!ip->i_ino ||
3210		    (XFS_INO_TO_AGINO(mp, iq->i_ino) & mask) != first_index) {
3211			spin_unlock(&ip->i_flags_lock);
3212			continue;
3213		}
3214		spin_unlock(&ip->i_flags_lock);
 
 
 
 
 
 
 
 
 
 
3215
3216		/*
3217		 * Do an un-protected check to see if the inode is dirty and
3218		 * is a candidate for flushing.  These checks will be repeated
3219		 * later after the appropriate locks are acquired.
3220		 */
3221		if (xfs_inode_clean(iq) && xfs_ipincount(iq) == 0)
3222			continue;
3223
3224		/*
3225		 * Try to get locks.  If any are unavailable or it is pinned,
3226		 * then this inode cannot be flushed and is skipped.
3227		 */
3228
3229		if (!xfs_ilock_nowait(iq, XFS_ILOCK_SHARED))
3230			continue;
3231		if (!xfs_iflock_nowait(iq)) {
3232			xfs_iunlock(iq, XFS_ILOCK_SHARED);
3233			continue;
3234		}
3235		if (xfs_ipincount(iq)) {
3236			xfs_ifunlock(iq);
3237			xfs_iunlock(iq, XFS_ILOCK_SHARED);
 
 
 
 
 
 
 
 
 
 
 
 
 
3238			continue;
3239		}
3240
3241		/*
3242		 * arriving here means that this inode can be flushed.  First
3243		 * re-check that it's dirty before flushing.
3244		 */
3245		if (!xfs_inode_clean(iq)) {
3246			int	error;
3247			error = xfs_iflush_int(iq, bp);
3248			if (error) {
3249				xfs_iunlock(iq, XFS_ILOCK_SHARED);
3250				goto cluster_corrupt_out;
3251			}
3252			clcount++;
3253		} else {
3254			xfs_ifunlock(iq);
3255		}
3256		xfs_iunlock(iq, XFS_ILOCK_SHARED);
3257	}
3258
3259	if (clcount) {
3260		XFS_STATS_INC(mp, xs_icluster_flushcnt);
3261		XFS_STATS_ADD(mp, xs_icluster_flushinode, clcount);
3262	}
3263
3264out_free:
3265	rcu_read_unlock();
3266	kmem_free(ilist);
3267out_put:
3268	xfs_perag_put(pag);
3269	return 0;
3270
3271
3272cluster_corrupt_out:
3273	/*
3274	 * Corruption detected in the clustering loop.  Invalidate the
3275	 * inode buffer and shut down the filesystem.
3276	 */
3277	rcu_read_unlock();
 
3278	/*
3279	 * Clean up the buffer.  If it was delwri, just release it --
3280	 * brelse can handle it with no problems.  If not, shut down the
3281	 * filesystem before releasing the buffer.
3282	 */
3283	bufwasdelwri = (bp->b_flags & _XBF_DELWRI_Q);
3284	if (bufwasdelwri)
3285		xfs_buf_relse(bp);
 
 
 
 
 
3286
3287	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3288
3289	if (!bufwasdelwri) {
3290		/*
3291		 * Just like incore_relse: if we have b_iodone functions,
3292		 * mark the buffer as an error and call them.  Otherwise
3293		 * mark it as stale and brelse.
3294		 */
3295		if (bp->b_iodone) {
3296			bp->b_flags &= ~XBF_DONE;
3297			xfs_buf_stale(bp);
3298			xfs_buf_ioerror(bp, -EIO);
3299			xfs_buf_ioend(bp);
3300		} else {
3301			xfs_buf_stale(bp);
3302			xfs_buf_relse(bp);
3303		}
3304	}
3305
3306	/*
3307	 * Unlocks the flush lock
3308	 */
3309	xfs_iflush_abort(iq, false);
3310	kmem_free(ilist);
3311	xfs_perag_put(pag);
3312	return -EFSCORRUPTED;
3313}
3314
3315/*
3316 * Flush dirty inode metadata into the backing buffer.
3317 *
3318 * The caller must have the inode lock and the inode flush lock held.  The
3319 * inode lock will still be held upon return to the caller, and the inode
3320 * flush lock will be released after the inode has reached the disk.
3321 *
3322 * The caller must write out the buffer returned in *bpp and release it.
3323 */
3324int
3325xfs_iflush(
3326	struct xfs_inode	*ip,
3327	struct xfs_buf		**bpp)
3328{
3329	struct xfs_mount	*mp = ip->i_mount;
3330	struct xfs_buf		*bp;
3331	struct xfs_dinode	*dip;
3332	int			error;
3333
3334	XFS_STATS_INC(mp, xs_iflush_count);
3335
3336	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3337	ASSERT(xfs_isiflocked(ip));
3338	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3339	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3340
3341	*bpp = NULL;
3342
3343	xfs_iunpin_wait(ip);
3344
3345	/*
3346	 * For stale inodes we cannot rely on the backing buffer remaining
3347	 * stale in cache for the remaining life of the stale inode and so
3348	 * xfs_imap_to_bp() below may give us a buffer that no longer contains
3349	 * inodes below. We have to check this after ensuring the inode is
3350	 * unpinned so that it is safe to reclaim the stale inode after the
3351	 * flush call.
3352	 */
3353	if (xfs_iflags_test(ip, XFS_ISTALE)) {
3354		xfs_ifunlock(ip);
3355		return 0;
3356	}
3357
3358	/*
3359	 * This may have been unpinned because the filesystem is shutting
3360	 * down forcibly. If that's the case we must not write this inode
3361	 * to disk, because the log record didn't make it to disk.
3362	 *
3363	 * We also have to remove the log item from the AIL in this case,
3364	 * as we wait for an empty AIL as part of the unmount process.
3365	 */
3366	if (XFS_FORCED_SHUTDOWN(mp)) {
3367		error = -EIO;
3368		goto abort_out;
3369	}
3370
3371	/*
3372	 * Get the buffer containing the on-disk inode.
 
 
 
 
 
 
3373	 */
3374	error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, XBF_TRYLOCK,
3375			       0);
3376	if (error || !bp) {
3377		xfs_ifunlock(ip);
3378		return error;
3379	}
 
 
3380
3381	/*
3382	 * First flush out the inode that xfs_iflush was called with.
3383	 */
3384	error = xfs_iflush_int(ip, bp);
3385	if (error)
3386		goto corrupt_out;
3387
3388	/*
3389	 * If the buffer is pinned then push on the log now so we won't
3390	 * get stuck waiting in the write for too long.
3391	 */
3392	if (xfs_buf_ispinned(bp))
3393		xfs_log_force(mp, 0);
3394
3395	/*
3396	 * inode clustering:
3397	 * see if other inodes can be gathered into this write
 
 
 
 
 
3398	 */
3399	error = xfs_iflush_cluster(ip, bp);
3400	if (error)
3401		goto cluster_corrupt_out;
3402
3403	*bpp = bp;
3404	return 0;
3405
3406corrupt_out:
3407	xfs_buf_relse(bp);
 
3408	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3409cluster_corrupt_out:
3410	error = -EFSCORRUPTED;
3411abort_out:
3412	/*
3413	 * Unlocks the flush lock
3414	 */
3415	xfs_iflush_abort(ip, false);
3416	return error;
3417}
3418
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3419STATIC int
3420xfs_iflush_int(
3421	struct xfs_inode	*ip,
3422	struct xfs_buf		*bp)
3423{
3424	struct xfs_inode_log_item *iip = ip->i_itemp;
3425	struct xfs_dinode	*dip;
3426	struct xfs_mount	*mp = ip->i_mount;
3427
3428	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3429	ASSERT(xfs_isiflocked(ip));
3430	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3431	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3432	ASSERT(iip != NULL && iip->ili_fields != 0);
3433	ASSERT(ip->i_d.di_version > 1);
3434
3435	/* set *dip = inode's place in the buffer */
3436	dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);
3437
3438	if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
3439			       mp, XFS_ERRTAG_IFLUSH_1, XFS_RANDOM_IFLUSH_1)) {
3440		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3441			"%s: Bad inode %Lu magic number 0x%x, ptr 0x%p",
3442			__func__, ip->i_ino, be16_to_cpu(dip->di_magic), dip);
3443		goto corrupt_out;
3444	}
3445	if (S_ISREG(VFS_I(ip)->i_mode)) {
3446		if (XFS_TEST_ERROR(
3447		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3448		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
3449		    mp, XFS_ERRTAG_IFLUSH_3, XFS_RANDOM_IFLUSH_3)) {
3450			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3451				"%s: Bad regular inode %Lu, ptr 0x%p",
3452				__func__, ip->i_ino, ip);
3453			goto corrupt_out;
3454		}
3455	} else if (S_ISDIR(VFS_I(ip)->i_mode)) {
3456		if (XFS_TEST_ERROR(
3457		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3458		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
3459		    (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
3460		    mp, XFS_ERRTAG_IFLUSH_4, XFS_RANDOM_IFLUSH_4)) {
3461			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3462				"%s: Bad directory inode %Lu, ptr 0x%p",
3463				__func__, ip->i_ino, ip);
3464			goto corrupt_out;
3465		}
3466	}
3467	if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
3468				ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5,
3469				XFS_RANDOM_IFLUSH_5)) {
3470		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3471			"%s: detected corrupt incore inode %Lu, "
3472			"total extents = %d, nblocks = %Ld, ptr 0x%p",
3473			__func__, ip->i_ino,
3474			ip->i_d.di_nextents + ip->i_d.di_anextents,
3475			ip->i_d.di_nblocks, ip);
3476		goto corrupt_out;
3477	}
3478	if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
3479				mp, XFS_ERRTAG_IFLUSH_6, XFS_RANDOM_IFLUSH_6)) {
3480		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3481			"%s: bad inode %Lu, forkoff 0x%x, ptr 0x%p",
3482			__func__, ip->i_ino, ip->i_d.di_forkoff, ip);
3483		goto corrupt_out;
3484	}
3485
3486	/*
3487	 * Inode item log recovery for v2 inodes are dependent on the
3488	 * di_flushiter count for correct sequencing. We bump the flush
3489	 * iteration count so we can detect flushes which postdate a log record
3490	 * during recovery. This is redundant as we now log every change and
3491	 * hence this can't happen but we need to still do it to ensure
3492	 * backwards compatibility with old kernels that predate logging all
3493	 * inode changes.
3494	 */
3495	if (ip->i_d.di_version < 3)
3496		ip->i_d.di_flushiter++;
3497
 
 
 
 
3498	/*
3499	 * Copy the dirty parts of the inode into the on-disk inode.  We always
3500	 * copy out the core of the inode, because if the inode is dirty at all
3501	 * the core must be.
3502	 */
3503	xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);
3504
3505	/* Wrap, we never let the log put out DI_MAX_FLUSH */
3506	if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
3507		ip->i_d.di_flushiter = 0;
3508
3509	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
3510	if (XFS_IFORK_Q(ip))
3511		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
3512	xfs_inobp_check(mp, bp);
3513
3514	/*
3515	 * We've recorded everything logged in the inode, so we'd like to clear
3516	 * the ili_fields bits so we don't log and flush things unnecessarily.
3517	 * However, we can't stop logging all this information until the data
3518	 * we've copied into the disk buffer is written to disk.  If we did we
3519	 * might overwrite the copy of the inode in the log with all the data
3520	 * after re-logging only part of it, and in the face of a crash we
3521	 * wouldn't have all the data we need to recover.
3522	 *
3523	 * What we do is move the bits to the ili_last_fields field.  When
3524	 * logging the inode, these bits are moved back to the ili_fields field.
3525	 * In the xfs_iflush_done() routine we clear ili_last_fields, since we
3526	 * know that the information those bits represent is permanently on
3527	 * disk.  As long as the flush completes before the inode is logged
3528	 * again, then both ili_fields and ili_last_fields will be cleared.
3529	 *
3530	 * We can play with the ili_fields bits here, because the inode lock
3531	 * must be held exclusively in order to set bits there and the flush
3532	 * lock protects the ili_last_fields bits.  Set ili_logged so the flush
3533	 * done routine can tell whether or not to look in the AIL.  Also, store
3534	 * the current LSN of the inode so that we can tell whether the item has
3535	 * moved in the AIL from xfs_iflush_done().  In order to read the lsn we
3536	 * need the AIL lock, because it is a 64 bit value that cannot be read
3537	 * atomically.
3538	 */
3539	iip->ili_last_fields = iip->ili_fields;
3540	iip->ili_fields = 0;
3541	iip->ili_fsync_fields = 0;
3542	iip->ili_logged = 1;
3543
3544	xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
3545				&iip->ili_item.li_lsn);
3546
3547	/*
3548	 * Attach the function xfs_iflush_done to the inode's
3549	 * buffer.  This will remove the inode from the AIL
3550	 * and unlock the inode's flush lock when the inode is
3551	 * completely written to disk.
3552	 */
3553	xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);
3554
3555	/* generate the checksum. */
3556	xfs_dinode_calc_crc(mp, dip);
3557
3558	ASSERT(bp->b_fspriv != NULL);
3559	ASSERT(bp->b_iodone != NULL);
3560	return 0;
3561
3562corrupt_out:
3563	return -EFSCORRUPTED;
 
 
 
 
 
 
 
 
 
3564}