xref: /openbmc/linux/fs/xfs/xfs_inode.c (revision 0d83620f)
1 /*
2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #include <linux/log2.h>
19 
20 #include "xfs.h"
21 #include "xfs_fs.h"
22 #include "xfs_shared.h"
23 #include "xfs_format.h"
24 #include "xfs_log_format.h"
25 #include "xfs_trans_resv.h"
26 #include "xfs_sb.h"
27 #include "xfs_mount.h"
28 #include "xfs_defer.h"
29 #include "xfs_inode.h"
30 #include "xfs_da_format.h"
31 #include "xfs_da_btree.h"
32 #include "xfs_dir2.h"
33 #include "xfs_attr_sf.h"
34 #include "xfs_attr.h"
35 #include "xfs_trans_space.h"
36 #include "xfs_trans.h"
37 #include "xfs_buf_item.h"
38 #include "xfs_inode_item.h"
39 #include "xfs_ialloc.h"
40 #include "xfs_bmap.h"
41 #include "xfs_bmap_util.h"
42 #include "xfs_errortag.h"
43 #include "xfs_error.h"
44 #include "xfs_quota.h"
45 #include "xfs_filestream.h"
46 #include "xfs_cksum.h"
47 #include "xfs_trace.h"
48 #include "xfs_icache.h"
49 #include "xfs_symlink.h"
50 #include "xfs_trans_priv.h"
51 #include "xfs_log.h"
52 #include "xfs_bmap_btree.h"
53 #include "xfs_reflink.h"
54 #include "xfs_dir2_priv.h"
55 
56 kmem_zone_t *xfs_inode_zone;
57 
58 /*
59  * Used in xfs_itruncate_extents().  This is the maximum number of extents
60  * freed from a file in a single transaction.
61  */
62 #define	XFS_ITRUNC_MAX_EXTENTS	2
63 
64 STATIC int xfs_iflush_int(struct xfs_inode *, struct xfs_buf *);
65 STATIC int xfs_iunlink(struct xfs_trans *, struct xfs_inode *);
66 STATIC int xfs_iunlink_remove(struct xfs_trans *, struct xfs_inode *);
67 
68 /*
69  * helper function to extract extent size hint from inode
70  */
71 xfs_extlen_t
72 xfs_get_extsz_hint(
73 	struct xfs_inode	*ip)
74 {
75 	if ((ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE) && ip->i_d.di_extsize)
76 		return ip->i_d.di_extsize;
77 	if (XFS_IS_REALTIME_INODE(ip))
78 		return ip->i_mount->m_sb.sb_rextsize;
79 	return 0;
80 }
81 
82 /*
83  * Helper function to extract CoW extent size hint from inode.
84  * Between the extent size hint and the CoW extent size hint, we
85  * return the greater of the two.  If the value is zero (automatic),
86  * use the default size.
87  */
88 xfs_extlen_t
89 xfs_get_cowextsz_hint(
90 	struct xfs_inode	*ip)
91 {
92 	xfs_extlen_t		a, b;
93 
94 	a = 0;
95 	if (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
96 		a = ip->i_d.di_cowextsize;
97 	b = xfs_get_extsz_hint(ip);
98 
99 	a = max(a, b);
100 	if (a == 0)
101 		return XFS_DEFAULT_COWEXTSZ_HINT;
102 	return a;
103 }
104 
105 /*
106  * These two are wrapper routines around the xfs_ilock() routine used to
107  * centralize some grungy code.  They are used in places that wish to lock the
108  * inode solely for reading the extents.  The reason these places can't just
109  * call xfs_ilock(ip, XFS_ILOCK_SHARED) is that the inode lock also guards to
110  * bringing in of the extents from disk for a file in b-tree format.  If the
111  * inode is in b-tree format, then we need to lock the inode exclusively until
112  * the extents are read in.  Locking it exclusively all the time would limit
113  * our parallelism unnecessarily, though.  What we do instead is check to see
114  * if the extents have been read in yet, and only lock the inode exclusively
115  * if they have not.
116  *
117  * The functions return a value which should be given to the corresponding
118  * xfs_iunlock() call.
119  */
120 uint
121 xfs_ilock_data_map_shared(
122 	struct xfs_inode	*ip)
123 {
124 	uint			lock_mode = XFS_ILOCK_SHARED;
125 
126 	if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
127 	    (ip->i_df.if_flags & XFS_IFEXTENTS) == 0)
128 		lock_mode = XFS_ILOCK_EXCL;
129 	xfs_ilock(ip, lock_mode);
130 	return lock_mode;
131 }
132 
133 uint
134 xfs_ilock_attr_map_shared(
135 	struct xfs_inode	*ip)
136 {
137 	uint			lock_mode = XFS_ILOCK_SHARED;
138 
139 	if (ip->i_d.di_aformat == XFS_DINODE_FMT_BTREE &&
140 	    (ip->i_afp->if_flags & XFS_IFEXTENTS) == 0)
141 		lock_mode = XFS_ILOCK_EXCL;
142 	xfs_ilock(ip, lock_mode);
143 	return lock_mode;
144 }
145 
146 /*
147  * In addition to i_rwsem in the VFS inode, the xfs inode contains 2
148  * multi-reader locks: i_mmap_lock and the i_lock.  This routine allows
149  * various combinations of the locks to be obtained.
150  *
151  * The 3 locks should always be ordered so that the IO lock is obtained first,
152  * the mmap lock second and the ilock last in order to prevent deadlock.
153  *
154  * Basic locking order:
155  *
156  * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock
157  *
158  * mmap_sem locking order:
159  *
160  * i_rwsem -> page lock -> mmap_sem
161  * mmap_sem -> i_mmap_lock -> page_lock
162  *
163  * The difference in mmap_sem locking order mean that we cannot hold the
164  * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can
165  * fault in pages during copy in/out (for buffered IO) or require the mmap_sem
166  * in get_user_pages() to map the user pages into the kernel address space for
167  * direct IO. Similarly the i_rwsem cannot be taken inside a page fault because
168  * page faults already hold the mmap_sem.
169  *
170  * Hence to serialise fully against both syscall and mmap based IO, we need to
171  * take both the i_rwsem and the i_mmap_lock. These locks should *only* be both
172  * taken in places where we need to invalidate the page cache in a race
173  * free manner (e.g. truncate, hole punch and other extent manipulation
174  * functions).
175  */
176 void
177 xfs_ilock(
178 	xfs_inode_t		*ip,
179 	uint			lock_flags)
180 {
181 	trace_xfs_ilock(ip, lock_flags, _RET_IP_);
182 
183 	/*
184 	 * You can't set both SHARED and EXCL for the same lock,
185 	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
186 	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
187 	 */
188 	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
189 	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
190 	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
191 	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
192 	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
193 	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
194 	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
195 
196 	if (lock_flags & XFS_IOLOCK_EXCL) {
197 		down_write_nested(&VFS_I(ip)->i_rwsem,
198 				  XFS_IOLOCK_DEP(lock_flags));
199 	} else if (lock_flags & XFS_IOLOCK_SHARED) {
200 		down_read_nested(&VFS_I(ip)->i_rwsem,
201 				 XFS_IOLOCK_DEP(lock_flags));
202 	}
203 
204 	if (lock_flags & XFS_MMAPLOCK_EXCL)
205 		mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
206 	else if (lock_flags & XFS_MMAPLOCK_SHARED)
207 		mraccess_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
208 
209 	if (lock_flags & XFS_ILOCK_EXCL)
210 		mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
211 	else if (lock_flags & XFS_ILOCK_SHARED)
212 		mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
213 }
214 
215 /*
216  * This is just like xfs_ilock(), except that the caller
217  * is guaranteed not to sleep.  It returns 1 if it gets
218  * the requested locks and 0 otherwise.  If the IO lock is
219  * obtained but the inode lock cannot be, then the IO lock
220  * is dropped before returning.
221  *
222  * ip -- the inode being locked
223  * lock_flags -- this parameter indicates the inode's locks to be
224  *       to be locked.  See the comment for xfs_ilock() for a list
225  *	 of valid values.
226  */
227 int
228 xfs_ilock_nowait(
229 	xfs_inode_t		*ip,
230 	uint			lock_flags)
231 {
232 	trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
233 
234 	/*
235 	 * You can't set both SHARED and EXCL for the same lock,
236 	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
237 	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
238 	 */
239 	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
240 	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
241 	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
242 	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
243 	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
244 	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
245 	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
246 
247 	if (lock_flags & XFS_IOLOCK_EXCL) {
248 		if (!down_write_trylock(&VFS_I(ip)->i_rwsem))
249 			goto out;
250 	} else if (lock_flags & XFS_IOLOCK_SHARED) {
251 		if (!down_read_trylock(&VFS_I(ip)->i_rwsem))
252 			goto out;
253 	}
254 
255 	if (lock_flags & XFS_MMAPLOCK_EXCL) {
256 		if (!mrtryupdate(&ip->i_mmaplock))
257 			goto out_undo_iolock;
258 	} else if (lock_flags & XFS_MMAPLOCK_SHARED) {
259 		if (!mrtryaccess(&ip->i_mmaplock))
260 			goto out_undo_iolock;
261 	}
262 
263 	if (lock_flags & XFS_ILOCK_EXCL) {
264 		if (!mrtryupdate(&ip->i_lock))
265 			goto out_undo_mmaplock;
266 	} else if (lock_flags & XFS_ILOCK_SHARED) {
267 		if (!mrtryaccess(&ip->i_lock))
268 			goto out_undo_mmaplock;
269 	}
270 	return 1;
271 
272 out_undo_mmaplock:
273 	if (lock_flags & XFS_MMAPLOCK_EXCL)
274 		mrunlock_excl(&ip->i_mmaplock);
275 	else if (lock_flags & XFS_MMAPLOCK_SHARED)
276 		mrunlock_shared(&ip->i_mmaplock);
277 out_undo_iolock:
278 	if (lock_flags & XFS_IOLOCK_EXCL)
279 		up_write(&VFS_I(ip)->i_rwsem);
280 	else if (lock_flags & XFS_IOLOCK_SHARED)
281 		up_read(&VFS_I(ip)->i_rwsem);
282 out:
283 	return 0;
284 }
285 
286 /*
287  * xfs_iunlock() is used to drop the inode locks acquired with
288  * xfs_ilock() and xfs_ilock_nowait().  The caller must pass
289  * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
290  * that we know which locks to drop.
291  *
292  * ip -- the inode being unlocked
293  * lock_flags -- this parameter indicates the inode's locks to be
294  *       to be unlocked.  See the comment for xfs_ilock() for a list
295  *	 of valid values for this parameter.
296  *
297  */
298 void
299 xfs_iunlock(
300 	xfs_inode_t		*ip,
301 	uint			lock_flags)
302 {
303 	/*
304 	 * You can't set both SHARED and EXCL for the same lock,
305 	 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
306 	 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
307 	 */
308 	ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
309 	       (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
310 	ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
311 	       (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
312 	ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
313 	       (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
314 	ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
315 	ASSERT(lock_flags != 0);
316 
317 	if (lock_flags & XFS_IOLOCK_EXCL)
318 		up_write(&VFS_I(ip)->i_rwsem);
319 	else if (lock_flags & XFS_IOLOCK_SHARED)
320 		up_read(&VFS_I(ip)->i_rwsem);
321 
322 	if (lock_flags & XFS_MMAPLOCK_EXCL)
323 		mrunlock_excl(&ip->i_mmaplock);
324 	else if (lock_flags & XFS_MMAPLOCK_SHARED)
325 		mrunlock_shared(&ip->i_mmaplock);
326 
327 	if (lock_flags & XFS_ILOCK_EXCL)
328 		mrunlock_excl(&ip->i_lock);
329 	else if (lock_flags & XFS_ILOCK_SHARED)
330 		mrunlock_shared(&ip->i_lock);
331 
332 	trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
333 }
334 
335 /*
336  * give up write locks.  the i/o lock cannot be held nested
337  * if it is being demoted.
338  */
339 void
340 xfs_ilock_demote(
341 	xfs_inode_t		*ip,
342 	uint			lock_flags)
343 {
344 	ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL));
345 	ASSERT((lock_flags &
346 		~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
347 
348 	if (lock_flags & XFS_ILOCK_EXCL)
349 		mrdemote(&ip->i_lock);
350 	if (lock_flags & XFS_MMAPLOCK_EXCL)
351 		mrdemote(&ip->i_mmaplock);
352 	if (lock_flags & XFS_IOLOCK_EXCL)
353 		downgrade_write(&VFS_I(ip)->i_rwsem);
354 
355 	trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
356 }
357 
358 #if defined(DEBUG) || defined(XFS_WARN)
359 int
360 xfs_isilocked(
361 	xfs_inode_t		*ip,
362 	uint			lock_flags)
363 {
364 	if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
365 		if (!(lock_flags & XFS_ILOCK_SHARED))
366 			return !!ip->i_lock.mr_writer;
367 		return rwsem_is_locked(&ip->i_lock.mr_lock);
368 	}
369 
370 	if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) {
371 		if (!(lock_flags & XFS_MMAPLOCK_SHARED))
372 			return !!ip->i_mmaplock.mr_writer;
373 		return rwsem_is_locked(&ip->i_mmaplock.mr_lock);
374 	}
375 
376 	if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
377 		if (!(lock_flags & XFS_IOLOCK_SHARED))
378 			return !debug_locks ||
379 				lockdep_is_held_type(&VFS_I(ip)->i_rwsem, 0);
380 		return rwsem_is_locked(&VFS_I(ip)->i_rwsem);
381 	}
382 
383 	ASSERT(0);
384 	return 0;
385 }
386 #endif
387 
388 /*
389  * xfs_lockdep_subclass_ok() is only used in an ASSERT, so is only called when
390  * DEBUG or XFS_WARN is set. And MAX_LOCKDEP_SUBCLASSES is then only defined
391  * when CONFIG_LOCKDEP is set. Hence the complex define below to avoid build
392  * errors and warnings.
393  */
394 #if (defined(DEBUG) || defined(XFS_WARN)) && defined(CONFIG_LOCKDEP)
395 static bool
396 xfs_lockdep_subclass_ok(
397 	int subclass)
398 {
399 	return subclass < MAX_LOCKDEP_SUBCLASSES;
400 }
401 #else
402 #define xfs_lockdep_subclass_ok(subclass)	(true)
403 #endif
404 
405 /*
406  * Bump the subclass so xfs_lock_inodes() acquires each lock with a different
407  * value. This can be called for any type of inode lock combination, including
408  * parent locking. Care must be taken to ensure we don't overrun the subclass
409  * storage fields in the class mask we build.
410  */
411 static inline int
412 xfs_lock_inumorder(int lock_mode, int subclass)
413 {
414 	int	class = 0;
415 
416 	ASSERT(!(lock_mode & (XFS_ILOCK_PARENT | XFS_ILOCK_RTBITMAP |
417 			      XFS_ILOCK_RTSUM)));
418 	ASSERT(xfs_lockdep_subclass_ok(subclass));
419 
420 	if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) {
421 		ASSERT(subclass <= XFS_IOLOCK_MAX_SUBCLASS);
422 		class += subclass << XFS_IOLOCK_SHIFT;
423 	}
424 
425 	if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) {
426 		ASSERT(subclass <= XFS_MMAPLOCK_MAX_SUBCLASS);
427 		class += subclass << XFS_MMAPLOCK_SHIFT;
428 	}
429 
430 	if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) {
431 		ASSERT(subclass <= XFS_ILOCK_MAX_SUBCLASS);
432 		class += subclass << XFS_ILOCK_SHIFT;
433 	}
434 
435 	return (lock_mode & ~XFS_LOCK_SUBCLASS_MASK) | class;
436 }
437 
438 /*
439  * The following routine will lock n inodes in exclusive mode.  We assume the
440  * caller calls us with the inodes in i_ino order.
441  *
442  * We need to detect deadlock where an inode that we lock is in the AIL and we
443  * start waiting for another inode that is locked by a thread in a long running
444  * transaction (such as truncate). This can result in deadlock since the long
445  * running trans might need to wait for the inode we just locked in order to
446  * push the tail and free space in the log.
447  *
448  * xfs_lock_inodes() can only be used to lock one type of lock at a time -
449  * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
450  * lock more than one at a time, lockdep will report false positives saying we
451  * have violated locking orders.
452  */
453 static void
454 xfs_lock_inodes(
455 	xfs_inode_t	**ips,
456 	int		inodes,
457 	uint		lock_mode)
458 {
459 	int		attempts = 0, i, j, try_lock;
460 	xfs_log_item_t	*lp;
461 
462 	/*
463 	 * Currently supports between 2 and 5 inodes with exclusive locking.  We
464 	 * support an arbitrary depth of locking here, but absolute limits on
465 	 * inodes depend on the the type of locking and the limits placed by
466 	 * lockdep annotations in xfs_lock_inumorder.  These are all checked by
467 	 * the asserts.
468 	 */
469 	ASSERT(ips && inodes >= 2 && inodes <= 5);
470 	ASSERT(lock_mode & (XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL |
471 			    XFS_ILOCK_EXCL));
472 	ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED | XFS_MMAPLOCK_SHARED |
473 			      XFS_ILOCK_SHARED)));
474 	ASSERT(!(lock_mode & XFS_MMAPLOCK_EXCL) ||
475 		inodes <= XFS_MMAPLOCK_MAX_SUBCLASS + 1);
476 	ASSERT(!(lock_mode & XFS_ILOCK_EXCL) ||
477 		inodes <= XFS_ILOCK_MAX_SUBCLASS + 1);
478 
479 	if (lock_mode & XFS_IOLOCK_EXCL) {
480 		ASSERT(!(lock_mode & (XFS_MMAPLOCK_EXCL | XFS_ILOCK_EXCL)));
481 	} else if (lock_mode & XFS_MMAPLOCK_EXCL)
482 		ASSERT(!(lock_mode & XFS_ILOCK_EXCL));
483 
484 	try_lock = 0;
485 	i = 0;
486 again:
487 	for (; i < inodes; i++) {
488 		ASSERT(ips[i]);
489 
490 		if (i && (ips[i] == ips[i - 1]))	/* Already locked */
491 			continue;
492 
493 		/*
494 		 * If try_lock is not set yet, make sure all locked inodes are
495 		 * not in the AIL.  If any are, set try_lock to be used later.
496 		 */
497 		if (!try_lock) {
498 			for (j = (i - 1); j >= 0 && !try_lock; j--) {
499 				lp = (xfs_log_item_t *)ips[j]->i_itemp;
500 				if (lp && (lp->li_flags & XFS_LI_IN_AIL))
501 					try_lock++;
502 			}
503 		}
504 
505 		/*
506 		 * If any of the previous locks we have locked is in the AIL,
507 		 * we must TRY to get the second and subsequent locks. If
508 		 * we can't get any, we must release all we have
509 		 * and try again.
510 		 */
511 		if (!try_lock) {
512 			xfs_ilock(ips[i], xfs_lock_inumorder(lock_mode, i));
513 			continue;
514 		}
515 
516 		/* try_lock means we have an inode locked that is in the AIL. */
517 		ASSERT(i != 0);
518 		if (xfs_ilock_nowait(ips[i], xfs_lock_inumorder(lock_mode, i)))
519 			continue;
520 
521 		/*
522 		 * Unlock all previous guys and try again.  xfs_iunlock will try
523 		 * to push the tail if the inode is in the AIL.
524 		 */
525 		attempts++;
526 		for (j = i - 1; j >= 0; j--) {
527 			/*
528 			 * Check to see if we've already unlocked this one.  Not
529 			 * the first one going back, and the inode ptr is the
530 			 * same.
531 			 */
532 			if (j != (i - 1) && ips[j] == ips[j + 1])
533 				continue;
534 
535 			xfs_iunlock(ips[j], lock_mode);
536 		}
537 
538 		if ((attempts % 5) == 0) {
539 			delay(1); /* Don't just spin the CPU */
540 		}
541 		i = 0;
542 		try_lock = 0;
543 		goto again;
544 	}
545 }
546 
547 /*
548  * xfs_lock_two_inodes() can only be used to lock one type of lock at a time -
549  * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
550  * lock more than one at a time, lockdep will report false positives saying we
551  * have violated locking orders.
552  */
553 void
554 xfs_lock_two_inodes(
555 	xfs_inode_t		*ip0,
556 	xfs_inode_t		*ip1,
557 	uint			lock_mode)
558 {
559 	xfs_inode_t		*temp;
560 	int			attempts = 0;
561 	xfs_log_item_t		*lp;
562 
563 	ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
564 	if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL))
565 		ASSERT(!(lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
566 
567 	ASSERT(ip0->i_ino != ip1->i_ino);
568 
569 	if (ip0->i_ino > ip1->i_ino) {
570 		temp = ip0;
571 		ip0 = ip1;
572 		ip1 = temp;
573 	}
574 
575  again:
576 	xfs_ilock(ip0, xfs_lock_inumorder(lock_mode, 0));
577 
578 	/*
579 	 * If the first lock we have locked is in the AIL, we must TRY to get
580 	 * the second lock. If we can't get it, we must release the first one
581 	 * and try again.
582 	 */
583 	lp = (xfs_log_item_t *)ip0->i_itemp;
584 	if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
585 		if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(lock_mode, 1))) {
586 			xfs_iunlock(ip0, lock_mode);
587 			if ((++attempts % 5) == 0)
588 				delay(1); /* Don't just spin the CPU */
589 			goto again;
590 		}
591 	} else {
592 		xfs_ilock(ip1, xfs_lock_inumorder(lock_mode, 1));
593 	}
594 }
595 
596 
597 void
598 __xfs_iflock(
599 	struct xfs_inode	*ip)
600 {
601 	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IFLOCK_BIT);
602 	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IFLOCK_BIT);
603 
604 	do {
605 		prepare_to_wait_exclusive(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
606 		if (xfs_isiflocked(ip))
607 			io_schedule();
608 	} while (!xfs_iflock_nowait(ip));
609 
610 	finish_wait(wq, &wait.wq_entry);
611 }
612 
613 STATIC uint
614 _xfs_dic2xflags(
615 	uint16_t		di_flags,
616 	uint64_t		di_flags2,
617 	bool			has_attr)
618 {
619 	uint			flags = 0;
620 
621 	if (di_flags & XFS_DIFLAG_ANY) {
622 		if (di_flags & XFS_DIFLAG_REALTIME)
623 			flags |= FS_XFLAG_REALTIME;
624 		if (di_flags & XFS_DIFLAG_PREALLOC)
625 			flags |= FS_XFLAG_PREALLOC;
626 		if (di_flags & XFS_DIFLAG_IMMUTABLE)
627 			flags |= FS_XFLAG_IMMUTABLE;
628 		if (di_flags & XFS_DIFLAG_APPEND)
629 			flags |= FS_XFLAG_APPEND;
630 		if (di_flags & XFS_DIFLAG_SYNC)
631 			flags |= FS_XFLAG_SYNC;
632 		if (di_flags & XFS_DIFLAG_NOATIME)
633 			flags |= FS_XFLAG_NOATIME;
634 		if (di_flags & XFS_DIFLAG_NODUMP)
635 			flags |= FS_XFLAG_NODUMP;
636 		if (di_flags & XFS_DIFLAG_RTINHERIT)
637 			flags |= FS_XFLAG_RTINHERIT;
638 		if (di_flags & XFS_DIFLAG_PROJINHERIT)
639 			flags |= FS_XFLAG_PROJINHERIT;
640 		if (di_flags & XFS_DIFLAG_NOSYMLINKS)
641 			flags |= FS_XFLAG_NOSYMLINKS;
642 		if (di_flags & XFS_DIFLAG_EXTSIZE)
643 			flags |= FS_XFLAG_EXTSIZE;
644 		if (di_flags & XFS_DIFLAG_EXTSZINHERIT)
645 			flags |= FS_XFLAG_EXTSZINHERIT;
646 		if (di_flags & XFS_DIFLAG_NODEFRAG)
647 			flags |= FS_XFLAG_NODEFRAG;
648 		if (di_flags & XFS_DIFLAG_FILESTREAM)
649 			flags |= FS_XFLAG_FILESTREAM;
650 	}
651 
652 	if (di_flags2 & XFS_DIFLAG2_ANY) {
653 		if (di_flags2 & XFS_DIFLAG2_DAX)
654 			flags |= FS_XFLAG_DAX;
655 		if (di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
656 			flags |= FS_XFLAG_COWEXTSIZE;
657 	}
658 
659 	if (has_attr)
660 		flags |= FS_XFLAG_HASATTR;
661 
662 	return flags;
663 }
664 
665 uint
666 xfs_ip2xflags(
667 	struct xfs_inode	*ip)
668 {
669 	struct xfs_icdinode	*dic = &ip->i_d;
670 
671 	return _xfs_dic2xflags(dic->di_flags, dic->di_flags2, XFS_IFORK_Q(ip));
672 }
673 
674 /*
675  * Lookups up an inode from "name". If ci_name is not NULL, then a CI match
676  * is allowed, otherwise it has to be an exact match. If a CI match is found,
677  * ci_name->name will point to a the actual name (caller must free) or
678  * will be set to NULL if an exact match is found.
679  */
680 int
681 xfs_lookup(
682 	xfs_inode_t		*dp,
683 	struct xfs_name		*name,
684 	xfs_inode_t		**ipp,
685 	struct xfs_name		*ci_name)
686 {
687 	xfs_ino_t		inum;
688 	int			error;
689 
690 	trace_xfs_lookup(dp, name);
691 
692 	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
693 		return -EIO;
694 
695 	error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
696 	if (error)
697 		goto out_unlock;
698 
699 	error = xfs_iget(dp->i_mount, NULL, inum, 0, 0, ipp);
700 	if (error)
701 		goto out_free_name;
702 
703 	return 0;
704 
705 out_free_name:
706 	if (ci_name)
707 		kmem_free(ci_name->name);
708 out_unlock:
709 	*ipp = NULL;
710 	return error;
711 }
712 
713 /*
714  * Allocate an inode on disk and return a copy of its in-core version.
715  * The in-core inode is locked exclusively.  Set mode, nlink, and rdev
716  * appropriately within the inode.  The uid and gid for the inode are
717  * set according to the contents of the given cred structure.
718  *
719  * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
720  * has a free inode available, call xfs_iget() to obtain the in-core
721  * version of the allocated inode.  Finally, fill in the inode and
722  * log its initial contents.  In this case, ialloc_context would be
723  * set to NULL.
724  *
725  * If xfs_dialloc() does not have an available inode, it will replenish
726  * its supply by doing an allocation. Since we can only do one
727  * allocation within a transaction without deadlocks, we must commit
728  * the current transaction before returning the inode itself.
729  * In this case, therefore, we will set ialloc_context and return.
730  * The caller should then commit the current transaction, start a new
731  * transaction, and call xfs_ialloc() again to actually get the inode.
732  *
733  * To ensure that some other process does not grab the inode that
734  * was allocated during the first call to xfs_ialloc(), this routine
735  * also returns the [locked] bp pointing to the head of the freelist
736  * as ialloc_context.  The caller should hold this buffer across
737  * the commit and pass it back into this routine on the second call.
738  *
739  * If we are allocating quota inodes, we do not have a parent inode
740  * to attach to or associate with (i.e. pip == NULL) because they
741  * are not linked into the directory structure - they are attached
742  * directly to the superblock - and so have no parent.
743  */
744 static int
745 xfs_ialloc(
746 	xfs_trans_t	*tp,
747 	xfs_inode_t	*pip,
748 	umode_t		mode,
749 	xfs_nlink_t	nlink,
750 	dev_t		rdev,
751 	prid_t		prid,
752 	xfs_buf_t	**ialloc_context,
753 	xfs_inode_t	**ipp)
754 {
755 	struct xfs_mount *mp = tp->t_mountp;
756 	xfs_ino_t	ino;
757 	xfs_inode_t	*ip;
758 	uint		flags;
759 	int		error;
760 	struct timespec	tv;
761 	struct inode	*inode;
762 
763 	/*
764 	 * Call the space management code to pick
765 	 * the on-disk inode to be allocated.
766 	 */
767 	error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode,
768 			    ialloc_context, &ino);
769 	if (error)
770 		return error;
771 	if (*ialloc_context || ino == NULLFSINO) {
772 		*ipp = NULL;
773 		return 0;
774 	}
775 	ASSERT(*ialloc_context == NULL);
776 
777 	/*
778 	 * Get the in-core inode with the lock held exclusively.
779 	 * This is because we're setting fields here we need
780 	 * to prevent others from looking at until we're done.
781 	 */
782 	error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE,
783 			 XFS_ILOCK_EXCL, &ip);
784 	if (error)
785 		return error;
786 	ASSERT(ip != NULL);
787 	inode = VFS_I(ip);
788 
789 	/*
790 	 * We always convert v1 inodes to v2 now - we only support filesystems
791 	 * with >= v2 inode capability, so there is no reason for ever leaving
792 	 * an inode in v1 format.
793 	 */
794 	if (ip->i_d.di_version == 1)
795 		ip->i_d.di_version = 2;
796 
797 	inode->i_mode = mode;
798 	set_nlink(inode, nlink);
799 	ip->i_d.di_uid = xfs_kuid_to_uid(current_fsuid());
800 	ip->i_d.di_gid = xfs_kgid_to_gid(current_fsgid());
801 	inode->i_rdev = rdev;
802 	xfs_set_projid(ip, prid);
803 
804 	if (pip && XFS_INHERIT_GID(pip)) {
805 		ip->i_d.di_gid = pip->i_d.di_gid;
806 		if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode))
807 			inode->i_mode |= S_ISGID;
808 	}
809 
810 	/*
811 	 * If the group ID of the new file does not match the effective group
812 	 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
813 	 * (and only if the irix_sgid_inherit compatibility variable is set).
814 	 */
815 	if ((irix_sgid_inherit) &&
816 	    (inode->i_mode & S_ISGID) &&
817 	    (!in_group_p(xfs_gid_to_kgid(ip->i_d.di_gid))))
818 		inode->i_mode &= ~S_ISGID;
819 
820 	ip->i_d.di_size = 0;
821 	ip->i_d.di_nextents = 0;
822 	ASSERT(ip->i_d.di_nblocks == 0);
823 
824 	tv = current_time(inode);
825 	inode->i_mtime = tv;
826 	inode->i_atime = tv;
827 	inode->i_ctime = tv;
828 
829 	ip->i_d.di_extsize = 0;
830 	ip->i_d.di_dmevmask = 0;
831 	ip->i_d.di_dmstate = 0;
832 	ip->i_d.di_flags = 0;
833 
834 	if (ip->i_d.di_version == 3) {
835 		inode->i_version = 1;
836 		ip->i_d.di_flags2 = 0;
837 		ip->i_d.di_cowextsize = 0;
838 		ip->i_d.di_crtime.t_sec = (int32_t)tv.tv_sec;
839 		ip->i_d.di_crtime.t_nsec = (int32_t)tv.tv_nsec;
840 	}
841 
842 
843 	flags = XFS_ILOG_CORE;
844 	switch (mode & S_IFMT) {
845 	case S_IFIFO:
846 	case S_IFCHR:
847 	case S_IFBLK:
848 	case S_IFSOCK:
849 		ip->i_d.di_format = XFS_DINODE_FMT_DEV;
850 		ip->i_df.if_flags = 0;
851 		flags |= XFS_ILOG_DEV;
852 		break;
853 	case S_IFREG:
854 	case S_IFDIR:
855 		if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
856 			uint		di_flags = 0;
857 
858 			if (S_ISDIR(mode)) {
859 				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
860 					di_flags |= XFS_DIFLAG_RTINHERIT;
861 				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
862 					di_flags |= XFS_DIFLAG_EXTSZINHERIT;
863 					ip->i_d.di_extsize = pip->i_d.di_extsize;
864 				}
865 				if (pip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
866 					di_flags |= XFS_DIFLAG_PROJINHERIT;
867 			} else if (S_ISREG(mode)) {
868 				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
869 					di_flags |= XFS_DIFLAG_REALTIME;
870 				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
871 					di_flags |= XFS_DIFLAG_EXTSIZE;
872 					ip->i_d.di_extsize = pip->i_d.di_extsize;
873 				}
874 			}
875 			if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
876 			    xfs_inherit_noatime)
877 				di_flags |= XFS_DIFLAG_NOATIME;
878 			if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
879 			    xfs_inherit_nodump)
880 				di_flags |= XFS_DIFLAG_NODUMP;
881 			if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
882 			    xfs_inherit_sync)
883 				di_flags |= XFS_DIFLAG_SYNC;
884 			if ((pip->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) &&
885 			    xfs_inherit_nosymlinks)
886 				di_flags |= XFS_DIFLAG_NOSYMLINKS;
887 			if ((pip->i_d.di_flags & XFS_DIFLAG_NODEFRAG) &&
888 			    xfs_inherit_nodefrag)
889 				di_flags |= XFS_DIFLAG_NODEFRAG;
890 			if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
891 				di_flags |= XFS_DIFLAG_FILESTREAM;
892 
893 			ip->i_d.di_flags |= di_flags;
894 		}
895 		if (pip &&
896 		    (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY) &&
897 		    pip->i_d.di_version == 3 &&
898 		    ip->i_d.di_version == 3) {
899 			uint64_t	di_flags2 = 0;
900 
901 			if (pip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) {
902 				di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
903 				ip->i_d.di_cowextsize = pip->i_d.di_cowextsize;
904 			}
905 			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
906 				di_flags2 |= XFS_DIFLAG2_DAX;
907 
908 			ip->i_d.di_flags2 |= di_flags2;
909 		}
910 		/* FALLTHROUGH */
911 	case S_IFLNK:
912 		ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
913 		ip->i_df.if_flags = XFS_IFEXTENTS;
914 		ip->i_df.if_bytes = ip->i_df.if_real_bytes = 0;
915 		ip->i_df.if_u1.if_root = NULL;
916 		break;
917 	default:
918 		ASSERT(0);
919 	}
920 	/*
921 	 * Attribute fork settings for new inode.
922 	 */
923 	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
924 	ip->i_d.di_anextents = 0;
925 
926 	/*
927 	 * Log the new values stuffed into the inode.
928 	 */
929 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
930 	xfs_trans_log_inode(tp, ip, flags);
931 
932 	/* now that we have an i_mode we can setup the inode structure */
933 	xfs_setup_inode(ip);
934 
935 	*ipp = ip;
936 	return 0;
937 }
938 
939 /*
940  * Allocates a new inode from disk and return a pointer to the
941  * incore copy. This routine will internally commit the current
942  * transaction and allocate a new one if the Space Manager needed
943  * to do an allocation to replenish the inode free-list.
944  *
945  * This routine is designed to be called from xfs_create and
946  * xfs_create_dir.
947  *
948  */
949 int
950 xfs_dir_ialloc(
951 	xfs_trans_t	**tpp,		/* input: current transaction;
952 					   output: may be a new transaction. */
953 	xfs_inode_t	*dp,		/* directory within whose allocate
954 					   the inode. */
955 	umode_t		mode,
956 	xfs_nlink_t	nlink,
957 	dev_t		rdev,
958 	prid_t		prid,		/* project id */
959 	xfs_inode_t	**ipp,		/* pointer to inode; it will be
960 					   locked. */
961 	int		*committed)
962 
963 {
964 	xfs_trans_t	*tp;
965 	xfs_inode_t	*ip;
966 	xfs_buf_t	*ialloc_context = NULL;
967 	int		code;
968 	void		*dqinfo;
969 	uint		tflags;
970 
971 	tp = *tpp;
972 	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
973 
974 	/*
975 	 * xfs_ialloc will return a pointer to an incore inode if
976 	 * the Space Manager has an available inode on the free
977 	 * list. Otherwise, it will do an allocation and replenish
978 	 * the freelist.  Since we can only do one allocation per
979 	 * transaction without deadlocks, we will need to commit the
980 	 * current transaction and start a new one.  We will then
981 	 * need to call xfs_ialloc again to get the inode.
982 	 *
983 	 * If xfs_ialloc did an allocation to replenish the freelist,
984 	 * it returns the bp containing the head of the freelist as
985 	 * ialloc_context. We will hold a lock on it across the
986 	 * transaction commit so that no other process can steal
987 	 * the inode(s) that we've just allocated.
988 	 */
989 	code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, &ialloc_context,
990 			&ip);
991 
992 	/*
993 	 * Return an error if we were unable to allocate a new inode.
994 	 * This should only happen if we run out of space on disk or
995 	 * encounter a disk error.
996 	 */
997 	if (code) {
998 		*ipp = NULL;
999 		return code;
1000 	}
1001 	if (!ialloc_context && !ip) {
1002 		*ipp = NULL;
1003 		return -ENOSPC;
1004 	}
1005 
1006 	/*
1007 	 * If the AGI buffer is non-NULL, then we were unable to get an
1008 	 * inode in one operation.  We need to commit the current
1009 	 * transaction and call xfs_ialloc() again.  It is guaranteed
1010 	 * to succeed the second time.
1011 	 */
1012 	if (ialloc_context) {
1013 		/*
1014 		 * Normally, xfs_trans_commit releases all the locks.
1015 		 * We call bhold to hang on to the ialloc_context across
1016 		 * the commit.  Holding this buffer prevents any other
1017 		 * processes from doing any allocations in this
1018 		 * allocation group.
1019 		 */
1020 		xfs_trans_bhold(tp, ialloc_context);
1021 
1022 		/*
1023 		 * We want the quota changes to be associated with the next
1024 		 * transaction, NOT this one. So, detach the dqinfo from this
1025 		 * and attach it to the next transaction.
1026 		 */
1027 		dqinfo = NULL;
1028 		tflags = 0;
1029 		if (tp->t_dqinfo) {
1030 			dqinfo = (void *)tp->t_dqinfo;
1031 			tp->t_dqinfo = NULL;
1032 			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
1033 			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
1034 		}
1035 
1036 		code = xfs_trans_roll(&tp);
1037 		if (committed != NULL)
1038 			*committed = 1;
1039 
1040 		/*
1041 		 * Re-attach the quota info that we detached from prev trx.
1042 		 */
1043 		if (dqinfo) {
1044 			tp->t_dqinfo = dqinfo;
1045 			tp->t_flags |= tflags;
1046 		}
1047 
1048 		if (code) {
1049 			xfs_buf_relse(ialloc_context);
1050 			*tpp = tp;
1051 			*ipp = NULL;
1052 			return code;
1053 		}
1054 		xfs_trans_bjoin(tp, ialloc_context);
1055 
1056 		/*
1057 		 * Call ialloc again. Since we've locked out all
1058 		 * other allocations in this allocation group,
1059 		 * this call should always succeed.
1060 		 */
1061 		code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
1062 				  &ialloc_context, &ip);
1063 
1064 		/*
1065 		 * If we get an error at this point, return to the caller
1066 		 * so that the current transaction can be aborted.
1067 		 */
1068 		if (code) {
1069 			*tpp = tp;
1070 			*ipp = NULL;
1071 			return code;
1072 		}
1073 		ASSERT(!ialloc_context && ip);
1074 
1075 	} else {
1076 		if (committed != NULL)
1077 			*committed = 0;
1078 	}
1079 
1080 	*ipp = ip;
1081 	*tpp = tp;
1082 
1083 	return 0;
1084 }
1085 
1086 /*
1087  * Decrement the link count on an inode & log the change.  If this causes the
1088  * link count to go to zero, move the inode to AGI unlinked list so that it can
1089  * be freed when the last active reference goes away via xfs_inactive().
1090  */
1091 static int			/* error */
1092 xfs_droplink(
1093 	xfs_trans_t *tp,
1094 	xfs_inode_t *ip)
1095 {
1096 	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1097 
1098 	drop_nlink(VFS_I(ip));
1099 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1100 
1101 	if (VFS_I(ip)->i_nlink)
1102 		return 0;
1103 
1104 	return xfs_iunlink(tp, ip);
1105 }
1106 
1107 /*
1108  * Increment the link count on an inode & log the change.
1109  */
1110 static int
1111 xfs_bumplink(
1112 	xfs_trans_t *tp,
1113 	xfs_inode_t *ip)
1114 {
1115 	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1116 
1117 	ASSERT(ip->i_d.di_version > 1);
1118 	inc_nlink(VFS_I(ip));
1119 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1120 	return 0;
1121 }
1122 
1123 int
1124 xfs_create(
1125 	xfs_inode_t		*dp,
1126 	struct xfs_name		*name,
1127 	umode_t			mode,
1128 	dev_t			rdev,
1129 	xfs_inode_t		**ipp)
1130 {
1131 	int			is_dir = S_ISDIR(mode);
1132 	struct xfs_mount	*mp = dp->i_mount;
1133 	struct xfs_inode	*ip = NULL;
1134 	struct xfs_trans	*tp = NULL;
1135 	int			error;
1136 	struct xfs_defer_ops	dfops;
1137 	xfs_fsblock_t		first_block;
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 	xfs_defer_init(&dfops, &first_block);
1190 
1191 	/*
1192 	 * Reserve disk quota and the inode.
1193 	 */
1194 	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1195 						pdqp, resblks, 1, 0);
1196 	if (error)
1197 		goto out_trans_cancel;
1198 
1199 	/*
1200 	 * A newly created regular or special file just has one directory
1201 	 * entry pointing to them, but a directory also the "." entry
1202 	 * pointing to itself.
1203 	 */
1204 	error = xfs_dir_ialloc(&tp, dp, mode, is_dir ? 2 : 1, rdev, prid, &ip,
1205 			NULL);
1206 	if (error)
1207 		goto out_trans_cancel;
1208 
1209 	/*
1210 	 * Now we join the directory inode to the transaction.  We do not do it
1211 	 * earlier because xfs_dir_ialloc might commit the previous transaction
1212 	 * (and release all the locks).  An error from here on will result in
1213 	 * the transaction cancel unlocking dp so don't do it explicitly in the
1214 	 * error path.
1215 	 */
1216 	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
1217 	unlock_dp_on_error = false;
1218 
1219 	error = xfs_dir_createname(tp, dp, name, ip->i_ino,
1220 					&first_block, &dfops, resblks ?
1221 					resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
1222 	if (error) {
1223 		ASSERT(error != -ENOSPC);
1224 		goto out_trans_cancel;
1225 	}
1226 	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1227 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1228 
1229 	if (is_dir) {
1230 		error = xfs_dir_init(tp, ip, dp);
1231 		if (error)
1232 			goto out_bmap_cancel;
1233 
1234 		error = xfs_bumplink(tp, dp);
1235 		if (error)
1236 			goto out_bmap_cancel;
1237 	}
1238 
1239 	/*
1240 	 * If this is a synchronous mount, make sure that the
1241 	 * create transaction goes to disk before returning to
1242 	 * the user.
1243 	 */
1244 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1245 		xfs_trans_set_sync(tp);
1246 
1247 	/*
1248 	 * Attach the dquot(s) to the inodes and modify them incore.
1249 	 * These ids of the inode couldn't have changed since the new
1250 	 * inode has been locked ever since it was created.
1251 	 */
1252 	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1253 
1254 	error = xfs_defer_finish(&tp, &dfops);
1255 	if (error)
1256 		goto out_bmap_cancel;
1257 
1258 	error = xfs_trans_commit(tp);
1259 	if (error)
1260 		goto out_release_inode;
1261 
1262 	xfs_qm_dqrele(udqp);
1263 	xfs_qm_dqrele(gdqp);
1264 	xfs_qm_dqrele(pdqp);
1265 
1266 	*ipp = ip;
1267 	return 0;
1268 
1269  out_bmap_cancel:
1270 	xfs_defer_cancel(&dfops);
1271  out_trans_cancel:
1272 	xfs_trans_cancel(tp);
1273  out_release_inode:
1274 	/*
1275 	 * Wait until after the current transaction is aborted to finish the
1276 	 * setup of the inode and release the inode.  This prevents recursive
1277 	 * transactions and deadlocks from xfs_inactive.
1278 	 */
1279 	if (ip) {
1280 		xfs_finish_inode_setup(ip);
1281 		IRELE(ip);
1282 	}
1283 
1284 	xfs_qm_dqrele(udqp);
1285 	xfs_qm_dqrele(gdqp);
1286 	xfs_qm_dqrele(pdqp);
1287 
1288 	if (unlock_dp_on_error)
1289 		xfs_iunlock(dp, XFS_ILOCK_EXCL);
1290 	return error;
1291 }
1292 
1293 int
1294 xfs_create_tmpfile(
1295 	struct xfs_inode	*dp,
1296 	struct dentry		*dentry,
1297 	umode_t			mode,
1298 	struct xfs_inode	**ipp)
1299 {
1300 	struct xfs_mount	*mp = dp->i_mount;
1301 	struct xfs_inode	*ip = NULL;
1302 	struct xfs_trans	*tp = NULL;
1303 	int			error;
1304 	prid_t                  prid;
1305 	struct xfs_dquot	*udqp = NULL;
1306 	struct xfs_dquot	*gdqp = NULL;
1307 	struct xfs_dquot	*pdqp = NULL;
1308 	struct xfs_trans_res	*tres;
1309 	uint			resblks;
1310 
1311 	if (XFS_FORCED_SHUTDOWN(mp))
1312 		return -EIO;
1313 
1314 	prid = xfs_get_initial_prid(dp);
1315 
1316 	/*
1317 	 * Make sure that we have allocated dquot(s) on disk.
1318 	 */
1319 	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1320 				xfs_kgid_to_gid(current_fsgid()), prid,
1321 				XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1322 				&udqp, &gdqp, &pdqp);
1323 	if (error)
1324 		return error;
1325 
1326 	resblks = XFS_IALLOC_SPACE_RES(mp);
1327 	tres = &M_RES(mp)->tr_create_tmpfile;
1328 
1329 	error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1330 	if (error)
1331 		goto out_release_inode;
1332 
1333 	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1334 						pdqp, resblks, 1, 0);
1335 	if (error)
1336 		goto out_trans_cancel;
1337 
1338 	error = xfs_dir_ialloc(&tp, dp, mode, 1, 0, prid, &ip, NULL);
1339 	if (error)
1340 		goto out_trans_cancel;
1341 
1342 	if (mp->m_flags & XFS_MOUNT_WSYNC)
1343 		xfs_trans_set_sync(tp);
1344 
1345 	/*
1346 	 * Attach the dquot(s) to the inodes and modify them incore.
1347 	 * These ids of the inode couldn't have changed since the new
1348 	 * inode has been locked ever since it was created.
1349 	 */
1350 	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1351 
1352 	error = xfs_iunlink(tp, ip);
1353 	if (error)
1354 		goto out_trans_cancel;
1355 
1356 	error = xfs_trans_commit(tp);
1357 	if (error)
1358 		goto out_release_inode;
1359 
1360 	xfs_qm_dqrele(udqp);
1361 	xfs_qm_dqrele(gdqp);
1362 	xfs_qm_dqrele(pdqp);
1363 
1364 	*ipp = ip;
1365 	return 0;
1366 
1367  out_trans_cancel:
1368 	xfs_trans_cancel(tp);
1369  out_release_inode:
1370 	/*
1371 	 * Wait until after the current transaction is aborted to finish the
1372 	 * setup of the inode and release the inode.  This prevents recursive
1373 	 * transactions and deadlocks from xfs_inactive.
1374 	 */
1375 	if (ip) {
1376 		xfs_finish_inode_setup(ip);
1377 		IRELE(ip);
1378 	}
1379 
1380 	xfs_qm_dqrele(udqp);
1381 	xfs_qm_dqrele(gdqp);
1382 	xfs_qm_dqrele(pdqp);
1383 
1384 	return error;
1385 }
1386 
1387 int
1388 xfs_link(
1389 	xfs_inode_t		*tdp,
1390 	xfs_inode_t		*sip,
1391 	struct xfs_name		*target_name)
1392 {
1393 	xfs_mount_t		*mp = tdp->i_mount;
1394 	xfs_trans_t		*tp;
1395 	int			error;
1396 	struct xfs_defer_ops	dfops;
1397 	xfs_fsblock_t           first_block;
1398 	int			resblks;
1399 
1400 	trace_xfs_link(tdp, target_name);
1401 
1402 	ASSERT(!S_ISDIR(VFS_I(sip)->i_mode));
1403 
1404 	if (XFS_FORCED_SHUTDOWN(mp))
1405 		return -EIO;
1406 
1407 	error = xfs_qm_dqattach(sip, 0);
1408 	if (error)
1409 		goto std_return;
1410 
1411 	error = xfs_qm_dqattach(tdp, 0);
1412 	if (error)
1413 		goto std_return;
1414 
1415 	resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
1416 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, resblks, 0, 0, &tp);
1417 	if (error == -ENOSPC) {
1418 		resblks = 0;
1419 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, 0, 0, 0, &tp);
1420 	}
1421 	if (error)
1422 		goto std_return;
1423 
1424 	xfs_lock_two_inodes(sip, tdp, XFS_ILOCK_EXCL);
1425 
1426 	xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
1427 	xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
1428 
1429 	/*
1430 	 * If we are using project inheritance, we only allow hard link
1431 	 * creation in our tree when the project IDs are the same; else
1432 	 * the tree quota mechanism could be circumvented.
1433 	 */
1434 	if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
1435 		     (xfs_get_projid(tdp) != xfs_get_projid(sip)))) {
1436 		error = -EXDEV;
1437 		goto error_return;
1438 	}
1439 
1440 	if (!resblks) {
1441 		error = xfs_dir_canenter(tp, tdp, target_name);
1442 		if (error)
1443 			goto error_return;
1444 	}
1445 
1446 	xfs_defer_init(&dfops, &first_block);
1447 
1448 	/*
1449 	 * Handle initial link state of O_TMPFILE inode
1450 	 */
1451 	if (VFS_I(sip)->i_nlink == 0) {
1452 		error = xfs_iunlink_remove(tp, sip);
1453 		if (error)
1454 			goto error_return;
1455 	}
1456 
1457 	error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
1458 					&first_block, &dfops, resblks);
1459 	if (error)
1460 		goto error_return;
1461 	xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1462 	xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
1463 
1464 	error = xfs_bumplink(tp, sip);
1465 	if (error)
1466 		goto error_return;
1467 
1468 	/*
1469 	 * If this is a synchronous mount, make sure that the
1470 	 * link transaction goes to disk before returning to
1471 	 * the user.
1472 	 */
1473 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1474 		xfs_trans_set_sync(tp);
1475 
1476 	error = xfs_defer_finish(&tp, &dfops);
1477 	if (error) {
1478 		xfs_defer_cancel(&dfops);
1479 		goto error_return;
1480 	}
1481 
1482 	return xfs_trans_commit(tp);
1483 
1484  error_return:
1485 	xfs_trans_cancel(tp);
1486  std_return:
1487 	return error;
1488 }
1489 
1490 /* Clear the reflink flag and the cowblocks tag if possible. */
1491 static void
1492 xfs_itruncate_clear_reflink_flags(
1493 	struct xfs_inode	*ip)
1494 {
1495 	struct xfs_ifork	*dfork;
1496 	struct xfs_ifork	*cfork;
1497 
1498 	if (!xfs_is_reflink_inode(ip))
1499 		return;
1500 	dfork = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
1501 	cfork = XFS_IFORK_PTR(ip, XFS_COW_FORK);
1502 	if (dfork->if_bytes == 0 && cfork->if_bytes == 0)
1503 		ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
1504 	if (cfork->if_bytes == 0)
1505 		xfs_inode_clear_cowblocks_tag(ip);
1506 }
1507 
1508 /*
1509  * Free up the underlying blocks past new_size.  The new size must be smaller
1510  * than the current size.  This routine can be used both for the attribute and
1511  * data fork, and does not modify the inode size, which is left to the caller.
1512  *
1513  * The transaction passed to this routine must have made a permanent log
1514  * reservation of at least XFS_ITRUNCATE_LOG_RES.  This routine may commit the
1515  * given transaction and start new ones, so make sure everything involved in
1516  * the transaction is tidy before calling here.  Some transaction will be
1517  * returned to the caller to be committed.  The incoming transaction must
1518  * already include the inode, and both inode locks must be held exclusively.
1519  * The inode must also be "held" within the transaction.  On return the inode
1520  * will be "held" within the returned transaction.  This routine does NOT
1521  * require any disk space to be reserved for it within the transaction.
1522  *
1523  * If we get an error, we must return with the inode locked and linked into the
1524  * current transaction. This keeps things simple for the higher level code,
1525  * because it always knows that the inode is locked and held in the transaction
1526  * that returns to it whether errors occur or not.  We don't mark the inode
1527  * dirty on error so that transactions can be easily aborted if possible.
1528  */
1529 int
1530 xfs_itruncate_extents(
1531 	struct xfs_trans	**tpp,
1532 	struct xfs_inode	*ip,
1533 	int			whichfork,
1534 	xfs_fsize_t		new_size)
1535 {
1536 	struct xfs_mount	*mp = ip->i_mount;
1537 	struct xfs_trans	*tp = *tpp;
1538 	struct xfs_defer_ops	dfops;
1539 	xfs_fsblock_t		first_block;
1540 	xfs_fileoff_t		first_unmap_block;
1541 	xfs_fileoff_t		last_block;
1542 	xfs_filblks_t		unmap_len;
1543 	int			error = 0;
1544 	int			done = 0;
1545 
1546 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1547 	ASSERT(!atomic_read(&VFS_I(ip)->i_count) ||
1548 	       xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1549 	ASSERT(new_size <= XFS_ISIZE(ip));
1550 	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
1551 	ASSERT(ip->i_itemp != NULL);
1552 	ASSERT(ip->i_itemp->ili_lock_flags == 0);
1553 	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1554 
1555 	trace_xfs_itruncate_extents_start(ip, new_size);
1556 
1557 	/*
1558 	 * Since it is possible for space to become allocated beyond
1559 	 * the end of the file (in a crash where the space is allocated
1560 	 * but the inode size is not yet updated), simply remove any
1561 	 * blocks which show up between the new EOF and the maximum
1562 	 * possible file size.  If the first block to be removed is
1563 	 * beyond the maximum file size (ie it is the same as last_block),
1564 	 * then there is nothing to do.
1565 	 */
1566 	first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
1567 	last_block = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
1568 	if (first_unmap_block == last_block)
1569 		return 0;
1570 
1571 	ASSERT(first_unmap_block < last_block);
1572 	unmap_len = last_block - first_unmap_block + 1;
1573 	while (!done) {
1574 		xfs_defer_init(&dfops, &first_block);
1575 		error = xfs_bunmapi(tp, ip,
1576 				    first_unmap_block, unmap_len,
1577 				    xfs_bmapi_aflag(whichfork),
1578 				    XFS_ITRUNC_MAX_EXTENTS,
1579 				    &first_block, &dfops,
1580 				    &done);
1581 		if (error)
1582 			goto out_bmap_cancel;
1583 
1584 		/*
1585 		 * Duplicate the transaction that has the permanent
1586 		 * reservation and commit the old transaction.
1587 		 */
1588 		xfs_defer_ijoin(&dfops, ip);
1589 		error = xfs_defer_finish(&tp, &dfops);
1590 		if (error)
1591 			goto out_bmap_cancel;
1592 
1593 		error = xfs_trans_roll_inode(&tp, ip);
1594 		if (error)
1595 			goto out;
1596 	}
1597 
1598 	/* Remove all pending CoW reservations. */
1599 	error = xfs_reflink_cancel_cow_blocks(ip, &tp, first_unmap_block,
1600 			last_block, true);
1601 	if (error)
1602 		goto out;
1603 
1604 	xfs_itruncate_clear_reflink_flags(ip);
1605 
1606 	/*
1607 	 * Always re-log the inode so that our permanent transaction can keep
1608 	 * on rolling it forward in the log.
1609 	 */
1610 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1611 
1612 	trace_xfs_itruncate_extents_end(ip, new_size);
1613 
1614 out:
1615 	*tpp = tp;
1616 	return error;
1617 out_bmap_cancel:
1618 	/*
1619 	 * If the bunmapi call encounters an error, return to the caller where
1620 	 * the transaction can be properly aborted.  We just need to make sure
1621 	 * we're not holding any resources that we were not when we came in.
1622 	 */
1623 	xfs_defer_cancel(&dfops);
1624 	goto out;
1625 }
1626 
1627 int
1628 xfs_release(
1629 	xfs_inode_t	*ip)
1630 {
1631 	xfs_mount_t	*mp = ip->i_mount;
1632 	int		error;
1633 
1634 	if (!S_ISREG(VFS_I(ip)->i_mode) || (VFS_I(ip)->i_mode == 0))
1635 		return 0;
1636 
1637 	/* If this is a read-only mount, don't do this (would generate I/O) */
1638 	if (mp->m_flags & XFS_MOUNT_RDONLY)
1639 		return 0;
1640 
1641 	if (!XFS_FORCED_SHUTDOWN(mp)) {
1642 		int truncated;
1643 
1644 		/*
1645 		 * If we previously truncated this file and removed old data
1646 		 * in the process, we want to initiate "early" writeout on
1647 		 * the last close.  This is an attempt to combat the notorious
1648 		 * NULL files problem which is particularly noticeable from a
1649 		 * truncate down, buffered (re-)write (delalloc), followed by
1650 		 * a crash.  What we are effectively doing here is
1651 		 * significantly reducing the time window where we'd otherwise
1652 		 * be exposed to that problem.
1653 		 */
1654 		truncated = xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED);
1655 		if (truncated) {
1656 			xfs_iflags_clear(ip, XFS_IDIRTY_RELEASE);
1657 			if (ip->i_delayed_blks > 0) {
1658 				error = filemap_flush(VFS_I(ip)->i_mapping);
1659 				if (error)
1660 					return error;
1661 			}
1662 		}
1663 	}
1664 
1665 	if (VFS_I(ip)->i_nlink == 0)
1666 		return 0;
1667 
1668 	if (xfs_can_free_eofblocks(ip, false)) {
1669 
1670 		/*
1671 		 * Check if the inode is being opened, written and closed
1672 		 * frequently and we have delayed allocation blocks outstanding
1673 		 * (e.g. streaming writes from the NFS server), truncating the
1674 		 * blocks past EOF will cause fragmentation to occur.
1675 		 *
1676 		 * In this case don't do the truncation, but we have to be
1677 		 * careful how we detect this case. Blocks beyond EOF show up as
1678 		 * i_delayed_blks even when the inode is clean, so we need to
1679 		 * truncate them away first before checking for a dirty release.
1680 		 * Hence on the first dirty close we will still remove the
1681 		 * speculative allocation, but after that we will leave it in
1682 		 * place.
1683 		 */
1684 		if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
1685 			return 0;
1686 		/*
1687 		 * If we can't get the iolock just skip truncating the blocks
1688 		 * past EOF because we could deadlock with the mmap_sem
1689 		 * otherwise. We'll get another chance to drop them once the
1690 		 * last reference to the inode is dropped, so we'll never leak
1691 		 * blocks permanently.
1692 		 */
1693 		if (xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1694 			error = xfs_free_eofblocks(ip);
1695 			xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1696 			if (error)
1697 				return error;
1698 		}
1699 
1700 		/* delalloc blocks after truncation means it really is dirty */
1701 		if (ip->i_delayed_blks)
1702 			xfs_iflags_set(ip, XFS_IDIRTY_RELEASE);
1703 	}
1704 	return 0;
1705 }
1706 
1707 /*
1708  * xfs_inactive_truncate
1709  *
1710  * Called to perform a truncate when an inode becomes unlinked.
1711  */
1712 STATIC int
1713 xfs_inactive_truncate(
1714 	struct xfs_inode *ip)
1715 {
1716 	struct xfs_mount	*mp = ip->i_mount;
1717 	struct xfs_trans	*tp;
1718 	int			error;
1719 
1720 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
1721 	if (error) {
1722 		ASSERT(XFS_FORCED_SHUTDOWN(mp));
1723 		return error;
1724 	}
1725 
1726 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1727 	xfs_trans_ijoin(tp, ip, 0);
1728 
1729 	/*
1730 	 * Log the inode size first to prevent stale data exposure in the event
1731 	 * of a system crash before the truncate completes. See the related
1732 	 * comment in xfs_vn_setattr_size() for details.
1733 	 */
1734 	ip->i_d.di_size = 0;
1735 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1736 
1737 	error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
1738 	if (error)
1739 		goto error_trans_cancel;
1740 
1741 	ASSERT(ip->i_d.di_nextents == 0);
1742 
1743 	error = xfs_trans_commit(tp);
1744 	if (error)
1745 		goto error_unlock;
1746 
1747 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1748 	return 0;
1749 
1750 error_trans_cancel:
1751 	xfs_trans_cancel(tp);
1752 error_unlock:
1753 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1754 	return error;
1755 }
1756 
1757 /*
1758  * xfs_inactive_ifree()
1759  *
1760  * Perform the inode free when an inode is unlinked.
1761  */
1762 STATIC int
1763 xfs_inactive_ifree(
1764 	struct xfs_inode *ip)
1765 {
1766 	struct xfs_defer_ops	dfops;
1767 	xfs_fsblock_t		first_block;
1768 	struct xfs_mount	*mp = ip->i_mount;
1769 	struct xfs_trans	*tp;
1770 	int			error;
1771 
1772 	/*
1773 	 * We try to use a per-AG reservation for any block needed by the finobt
1774 	 * tree, but as the finobt feature predates the per-AG reservation
1775 	 * support a degraded file system might not have enough space for the
1776 	 * reservation at mount time.  In that case try to dip into the reserved
1777 	 * pool and pray.
1778 	 *
1779 	 * Send a warning if the reservation does happen to fail, as the inode
1780 	 * now remains allocated and sits on the unlinked list until the fs is
1781 	 * repaired.
1782 	 */
1783 	if (unlikely(mp->m_inotbt_nores)) {
1784 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree,
1785 				XFS_IFREE_SPACE_RES(mp), 0, XFS_TRANS_RESERVE,
1786 				&tp);
1787 	} else {
1788 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree, 0, 0, 0, &tp);
1789 	}
1790 	if (error) {
1791 		if (error == -ENOSPC) {
1792 			xfs_warn_ratelimited(mp,
1793 			"Failed to remove inode(s) from unlinked list. "
1794 			"Please free space, unmount and run xfs_repair.");
1795 		} else {
1796 			ASSERT(XFS_FORCED_SHUTDOWN(mp));
1797 		}
1798 		return error;
1799 	}
1800 
1801 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1802 	xfs_trans_ijoin(tp, ip, 0);
1803 
1804 	xfs_defer_init(&dfops, &first_block);
1805 	error = xfs_ifree(tp, ip, &dfops);
1806 	if (error) {
1807 		/*
1808 		 * If we fail to free the inode, shut down.  The cancel
1809 		 * might do that, we need to make sure.  Otherwise the
1810 		 * inode might be lost for a long time or forever.
1811 		 */
1812 		if (!XFS_FORCED_SHUTDOWN(mp)) {
1813 			xfs_notice(mp, "%s: xfs_ifree returned error %d",
1814 				__func__, error);
1815 			xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1816 		}
1817 		xfs_trans_cancel(tp);
1818 		xfs_iunlock(ip, XFS_ILOCK_EXCL);
1819 		return error;
1820 	}
1821 
1822 	/*
1823 	 * Credit the quota account(s). The inode is gone.
1824 	 */
1825 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_ICOUNT, -1);
1826 
1827 	/*
1828 	 * Just ignore errors at this point.  There is nothing we can do except
1829 	 * to try to keep going. Make sure it's not a silent error.
1830 	 */
1831 	error = xfs_defer_finish(&tp, &dfops);
1832 	if (error) {
1833 		xfs_notice(mp, "%s: xfs_defer_finish returned error %d",
1834 			__func__, error);
1835 		xfs_defer_cancel(&dfops);
1836 	}
1837 	error = xfs_trans_commit(tp);
1838 	if (error)
1839 		xfs_notice(mp, "%s: xfs_trans_commit returned error %d",
1840 			__func__, error);
1841 
1842 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1843 	return 0;
1844 }
1845 
1846 /*
1847  * xfs_inactive
1848  *
1849  * This is called when the vnode reference count for the vnode
1850  * goes to zero.  If the file has been unlinked, then it must
1851  * now be truncated.  Also, we clear all of the read-ahead state
1852  * kept for the inode here since the file is now closed.
1853  */
1854 void
1855 xfs_inactive(
1856 	xfs_inode_t	*ip)
1857 {
1858 	struct xfs_mount	*mp;
1859 	int			error;
1860 	int			truncate = 0;
1861 
1862 	/*
1863 	 * If the inode is already free, then there can be nothing
1864 	 * to clean up here.
1865 	 */
1866 	if (VFS_I(ip)->i_mode == 0) {
1867 		ASSERT(ip->i_df.if_real_bytes == 0);
1868 		ASSERT(ip->i_df.if_broot_bytes == 0);
1869 		return;
1870 	}
1871 
1872 	mp = ip->i_mount;
1873 	ASSERT(!xfs_iflags_test(ip, XFS_IRECOVERY));
1874 
1875 	/* If this is a read-only mount, don't do this (would generate I/O) */
1876 	if (mp->m_flags & XFS_MOUNT_RDONLY)
1877 		return;
1878 
1879 	if (VFS_I(ip)->i_nlink != 0) {
1880 		/*
1881 		 * force is true because we are evicting an inode from the
1882 		 * cache. Post-eof blocks must be freed, lest we end up with
1883 		 * broken free space accounting.
1884 		 *
1885 		 * Note: don't bother with iolock here since lockdep complains
1886 		 * about acquiring it in reclaim context. We have the only
1887 		 * reference to the inode at this point anyways.
1888 		 */
1889 		if (xfs_can_free_eofblocks(ip, true))
1890 			xfs_free_eofblocks(ip);
1891 
1892 		return;
1893 	}
1894 
1895 	if (S_ISREG(VFS_I(ip)->i_mode) &&
1896 	    (ip->i_d.di_size != 0 || XFS_ISIZE(ip) != 0 ||
1897 	     ip->i_d.di_nextents > 0 || ip->i_delayed_blks > 0))
1898 		truncate = 1;
1899 
1900 	error = xfs_qm_dqattach(ip, 0);
1901 	if (error)
1902 		return;
1903 
1904 	if (S_ISLNK(VFS_I(ip)->i_mode))
1905 		error = xfs_inactive_symlink(ip);
1906 	else if (truncate)
1907 		error = xfs_inactive_truncate(ip);
1908 	if (error)
1909 		return;
1910 
1911 	/*
1912 	 * If there are attributes associated with the file then blow them away
1913 	 * now.  The code calls a routine that recursively deconstructs the
1914 	 * attribute fork. If also blows away the in-core attribute fork.
1915 	 */
1916 	if (XFS_IFORK_Q(ip)) {
1917 		error = xfs_attr_inactive(ip);
1918 		if (error)
1919 			return;
1920 	}
1921 
1922 	ASSERT(!ip->i_afp);
1923 	ASSERT(ip->i_d.di_anextents == 0);
1924 	ASSERT(ip->i_d.di_forkoff == 0);
1925 
1926 	/*
1927 	 * Free the inode.
1928 	 */
1929 	error = xfs_inactive_ifree(ip);
1930 	if (error)
1931 		return;
1932 
1933 	/*
1934 	 * Release the dquots held by inode, if any.
1935 	 */
1936 	xfs_qm_dqdetach(ip);
1937 }
1938 
1939 /*
1940  * This is called when the inode's link count goes to 0 or we are creating a
1941  * tmpfile via O_TMPFILE. In the case of a tmpfile, @ignore_linkcount will be
1942  * set to true as the link count is dropped to zero by the VFS after we've
1943  * created the file successfully, so we have to add it to the unlinked list
1944  * while the link count is non-zero.
1945  *
1946  * We place the on-disk inode on a list in the AGI.  It will be pulled from this
1947  * list when the inode is freed.
1948  */
1949 STATIC int
1950 xfs_iunlink(
1951 	struct xfs_trans *tp,
1952 	struct xfs_inode *ip)
1953 {
1954 	xfs_mount_t	*mp = tp->t_mountp;
1955 	xfs_agi_t	*agi;
1956 	xfs_dinode_t	*dip;
1957 	xfs_buf_t	*agibp;
1958 	xfs_buf_t	*ibp;
1959 	xfs_agino_t	agino;
1960 	short		bucket_index;
1961 	int		offset;
1962 	int		error;
1963 
1964 	ASSERT(VFS_I(ip)->i_mode != 0);
1965 
1966 	/*
1967 	 * Get the agi buffer first.  It ensures lock ordering
1968 	 * on the list.
1969 	 */
1970 	error = xfs_read_agi(mp, tp, XFS_INO_TO_AGNO(mp, ip->i_ino), &agibp);
1971 	if (error)
1972 		return error;
1973 	agi = XFS_BUF_TO_AGI(agibp);
1974 
1975 	/*
1976 	 * Get the index into the agi hash table for the
1977 	 * list this inode will go on.
1978 	 */
1979 	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
1980 	ASSERT(agino != 0);
1981 	bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
1982 	ASSERT(agi->agi_unlinked[bucket_index]);
1983 	ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino);
1984 
1985 	if (agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO)) {
1986 		/*
1987 		 * There is already another inode in the bucket we need
1988 		 * to add ourselves to.  Add us at the front of the list.
1989 		 * Here we put the head pointer into our next pointer,
1990 		 * and then we fall through to point the head at us.
1991 		 */
1992 		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
1993 				       0, 0);
1994 		if (error)
1995 			return error;
1996 
1997 		ASSERT(dip->di_next_unlinked == cpu_to_be32(NULLAGINO));
1998 		dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
1999 		offset = ip->i_imap.im_boffset +
2000 			offsetof(xfs_dinode_t, di_next_unlinked);
2001 
2002 		/* need to recalc the inode CRC if appropriate */
2003 		xfs_dinode_calc_crc(mp, dip);
2004 
2005 		xfs_trans_inode_buf(tp, ibp);
2006 		xfs_trans_log_buf(tp, ibp, offset,
2007 				  (offset + sizeof(xfs_agino_t) - 1));
2008 		xfs_inobp_check(mp, ibp);
2009 	}
2010 
2011 	/*
2012 	 * Point the bucket head pointer at the inode being inserted.
2013 	 */
2014 	ASSERT(agino != 0);
2015 	agi->agi_unlinked[bucket_index] = cpu_to_be32(agino);
2016 	offset = offsetof(xfs_agi_t, agi_unlinked) +
2017 		(sizeof(xfs_agino_t) * bucket_index);
2018 	xfs_trans_log_buf(tp, agibp, offset,
2019 			  (offset + sizeof(xfs_agino_t) - 1));
2020 	return 0;
2021 }
2022 
2023 /*
2024  * Pull the on-disk inode from the AGI unlinked list.
2025  */
2026 STATIC int
2027 xfs_iunlink_remove(
2028 	xfs_trans_t	*tp,
2029 	xfs_inode_t	*ip)
2030 {
2031 	xfs_ino_t	next_ino;
2032 	xfs_mount_t	*mp;
2033 	xfs_agi_t	*agi;
2034 	xfs_dinode_t	*dip;
2035 	xfs_buf_t	*agibp;
2036 	xfs_buf_t	*ibp;
2037 	xfs_agnumber_t	agno;
2038 	xfs_agino_t	agino;
2039 	xfs_agino_t	next_agino;
2040 	xfs_buf_t	*last_ibp;
2041 	xfs_dinode_t	*last_dip = NULL;
2042 	short		bucket_index;
2043 	int		offset, last_offset = 0;
2044 	int		error;
2045 
2046 	mp = tp->t_mountp;
2047 	agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
2048 
2049 	/*
2050 	 * Get the agi buffer first.  It ensures lock ordering
2051 	 * on the list.
2052 	 */
2053 	error = xfs_read_agi(mp, tp, agno, &agibp);
2054 	if (error)
2055 		return error;
2056 
2057 	agi = XFS_BUF_TO_AGI(agibp);
2058 
2059 	/*
2060 	 * Get the index into the agi hash table for the
2061 	 * list this inode will go on.
2062 	 */
2063 	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
2064 	ASSERT(agino != 0);
2065 	bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
2066 	ASSERT(agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO));
2067 	ASSERT(agi->agi_unlinked[bucket_index]);
2068 
2069 	if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
2070 		/*
2071 		 * We're at the head of the list.  Get the inode's on-disk
2072 		 * buffer to see if there is anyone after us on the list.
2073 		 * Only modify our next pointer if it is not already NULLAGINO.
2074 		 * This saves us the overhead of dealing with the buffer when
2075 		 * there is no need to change it.
2076 		 */
2077 		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2078 				       0, 0);
2079 		if (error) {
2080 			xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
2081 				__func__, error);
2082 			return error;
2083 		}
2084 		next_agino = be32_to_cpu(dip->di_next_unlinked);
2085 		ASSERT(next_agino != 0);
2086 		if (next_agino != NULLAGINO) {
2087 			dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2088 			offset = ip->i_imap.im_boffset +
2089 				offsetof(xfs_dinode_t, di_next_unlinked);
2090 
2091 			/* need to recalc the inode CRC if appropriate */
2092 			xfs_dinode_calc_crc(mp, dip);
2093 
2094 			xfs_trans_inode_buf(tp, ibp);
2095 			xfs_trans_log_buf(tp, ibp, offset,
2096 					  (offset + sizeof(xfs_agino_t) - 1));
2097 			xfs_inobp_check(mp, ibp);
2098 		} else {
2099 			xfs_trans_brelse(tp, ibp);
2100 		}
2101 		/*
2102 		 * Point the bucket head pointer at the next inode.
2103 		 */
2104 		ASSERT(next_agino != 0);
2105 		ASSERT(next_agino != agino);
2106 		agi->agi_unlinked[bucket_index] = cpu_to_be32(next_agino);
2107 		offset = offsetof(xfs_agi_t, agi_unlinked) +
2108 			(sizeof(xfs_agino_t) * bucket_index);
2109 		xfs_trans_log_buf(tp, agibp, offset,
2110 				  (offset + sizeof(xfs_agino_t) - 1));
2111 	} else {
2112 		/*
2113 		 * We need to search the list for the inode being freed.
2114 		 */
2115 		next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
2116 		last_ibp = NULL;
2117 		while (next_agino != agino) {
2118 			struct xfs_imap	imap;
2119 
2120 			if (last_ibp)
2121 				xfs_trans_brelse(tp, last_ibp);
2122 
2123 			imap.im_blkno = 0;
2124 			next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
2125 
2126 			error = xfs_imap(mp, tp, next_ino, &imap, 0);
2127 			if (error) {
2128 				xfs_warn(mp,
2129 	"%s: xfs_imap returned error %d.",
2130 					 __func__, error);
2131 				return error;
2132 			}
2133 
2134 			error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,
2135 					       &last_ibp, 0, 0);
2136 			if (error) {
2137 				xfs_warn(mp,
2138 	"%s: xfs_imap_to_bp returned error %d.",
2139 					__func__, error);
2140 				return error;
2141 			}
2142 
2143 			last_offset = imap.im_boffset;
2144 			next_agino = be32_to_cpu(last_dip->di_next_unlinked);
2145 			ASSERT(next_agino != NULLAGINO);
2146 			ASSERT(next_agino != 0);
2147 		}
2148 
2149 		/*
2150 		 * Now last_ibp points to the buffer previous to us on the
2151 		 * unlinked list.  Pull us from the list.
2152 		 */
2153 		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2154 				       0, 0);
2155 		if (error) {
2156 			xfs_warn(mp, "%s: xfs_imap_to_bp(2) returned error %d.",
2157 				__func__, error);
2158 			return error;
2159 		}
2160 		next_agino = be32_to_cpu(dip->di_next_unlinked);
2161 		ASSERT(next_agino != 0);
2162 		ASSERT(next_agino != agino);
2163 		if (next_agino != NULLAGINO) {
2164 			dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2165 			offset = ip->i_imap.im_boffset +
2166 				offsetof(xfs_dinode_t, di_next_unlinked);
2167 
2168 			/* need to recalc the inode CRC if appropriate */
2169 			xfs_dinode_calc_crc(mp, dip);
2170 
2171 			xfs_trans_inode_buf(tp, ibp);
2172 			xfs_trans_log_buf(tp, ibp, offset,
2173 					  (offset + sizeof(xfs_agino_t) - 1));
2174 			xfs_inobp_check(mp, ibp);
2175 		} else {
2176 			xfs_trans_brelse(tp, ibp);
2177 		}
2178 		/*
2179 		 * Point the previous inode on the list to the next inode.
2180 		 */
2181 		last_dip->di_next_unlinked = cpu_to_be32(next_agino);
2182 		ASSERT(next_agino != 0);
2183 		offset = last_offset + offsetof(xfs_dinode_t, di_next_unlinked);
2184 
2185 		/* need to recalc the inode CRC if appropriate */
2186 		xfs_dinode_calc_crc(mp, last_dip);
2187 
2188 		xfs_trans_inode_buf(tp, last_ibp);
2189 		xfs_trans_log_buf(tp, last_ibp, offset,
2190 				  (offset + sizeof(xfs_agino_t) - 1));
2191 		xfs_inobp_check(mp, last_ibp);
2192 	}
2193 	return 0;
2194 }
2195 
2196 /*
2197  * A big issue when freeing the inode cluster is that we _cannot_ skip any
2198  * inodes that are in memory - they all must be marked stale and attached to
2199  * the cluster buffer.
2200  */
2201 STATIC int
2202 xfs_ifree_cluster(
2203 	xfs_inode_t		*free_ip,
2204 	xfs_trans_t		*tp,
2205 	struct xfs_icluster	*xic)
2206 {
2207 	xfs_mount_t		*mp = free_ip->i_mount;
2208 	int			blks_per_cluster;
2209 	int			inodes_per_cluster;
2210 	int			nbufs;
2211 	int			i, j;
2212 	int			ioffset;
2213 	xfs_daddr_t		blkno;
2214 	xfs_buf_t		*bp;
2215 	xfs_inode_t		*ip;
2216 	xfs_inode_log_item_t	*iip;
2217 	xfs_log_item_t		*lip;
2218 	struct xfs_perag	*pag;
2219 	xfs_ino_t		inum;
2220 
2221 	inum = xic->first_ino;
2222 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, inum));
2223 	blks_per_cluster = xfs_icluster_size_fsb(mp);
2224 	inodes_per_cluster = blks_per_cluster << mp->m_sb.sb_inopblog;
2225 	nbufs = mp->m_ialloc_blks / blks_per_cluster;
2226 
2227 	for (j = 0; j < nbufs; j++, inum += inodes_per_cluster) {
2228 		/*
2229 		 * The allocation bitmap tells us which inodes of the chunk were
2230 		 * physically allocated. Skip the cluster if an inode falls into
2231 		 * a sparse region.
2232 		 */
2233 		ioffset = inum - xic->first_ino;
2234 		if ((xic->alloc & XFS_INOBT_MASK(ioffset)) == 0) {
2235 			ASSERT(do_mod(ioffset, inodes_per_cluster) == 0);
2236 			continue;
2237 		}
2238 
2239 		blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
2240 					 XFS_INO_TO_AGBNO(mp, inum));
2241 
2242 		/*
2243 		 * We obtain and lock the backing buffer first in the process
2244 		 * here, as we have to ensure that any dirty inode that we
2245 		 * can't get the flush lock on is attached to the buffer.
2246 		 * If we scan the in-memory inodes first, then buffer IO can
2247 		 * complete before we get a lock on it, and hence we may fail
2248 		 * to mark all the active inodes on the buffer stale.
2249 		 */
2250 		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
2251 					mp->m_bsize * blks_per_cluster,
2252 					XBF_UNMAPPED);
2253 
2254 		if (!bp)
2255 			return -ENOMEM;
2256 
2257 		/*
2258 		 * This buffer may not have been correctly initialised as we
2259 		 * didn't read it from disk. That's not important because we are
2260 		 * only using to mark the buffer as stale in the log, and to
2261 		 * attach stale cached inodes on it. That means it will never be
2262 		 * dispatched for IO. If it is, we want to know about it, and we
2263 		 * want it to fail. We can acheive this by adding a write
2264 		 * verifier to the buffer.
2265 		 */
2266 		 bp->b_ops = &xfs_inode_buf_ops;
2267 
2268 		/*
2269 		 * Walk the inodes already attached to the buffer and mark them
2270 		 * stale. These will all have the flush locks held, so an
2271 		 * in-memory inode walk can't lock them. By marking them all
2272 		 * stale first, we will not attempt to lock them in the loop
2273 		 * below as the XFS_ISTALE flag will be set.
2274 		 */
2275 		lip = bp->b_fspriv;
2276 		while (lip) {
2277 			if (lip->li_type == XFS_LI_INODE) {
2278 				iip = (xfs_inode_log_item_t *)lip;
2279 				ASSERT(iip->ili_logged == 1);
2280 				lip->li_cb = xfs_istale_done;
2281 				xfs_trans_ail_copy_lsn(mp->m_ail,
2282 							&iip->ili_flush_lsn,
2283 							&iip->ili_item.li_lsn);
2284 				xfs_iflags_set(iip->ili_inode, XFS_ISTALE);
2285 			}
2286 			lip = lip->li_bio_list;
2287 		}
2288 
2289 
2290 		/*
2291 		 * For each inode in memory attempt to add it to the inode
2292 		 * buffer and set it up for being staled on buffer IO
2293 		 * completion.  This is safe as we've locked out tail pushing
2294 		 * and flushing by locking the buffer.
2295 		 *
2296 		 * We have already marked every inode that was part of a
2297 		 * transaction stale above, which means there is no point in
2298 		 * even trying to lock them.
2299 		 */
2300 		for (i = 0; i < inodes_per_cluster; i++) {
2301 retry:
2302 			rcu_read_lock();
2303 			ip = radix_tree_lookup(&pag->pag_ici_root,
2304 					XFS_INO_TO_AGINO(mp, (inum + i)));
2305 
2306 			/* Inode not in memory, nothing to do */
2307 			if (!ip) {
2308 				rcu_read_unlock();
2309 				continue;
2310 			}
2311 
2312 			/*
2313 			 * because this is an RCU protected lookup, we could
2314 			 * find a recently freed or even reallocated inode
2315 			 * during the lookup. We need to check under the
2316 			 * i_flags_lock for a valid inode here. Skip it if it
2317 			 * is not valid, the wrong inode or stale.
2318 			 */
2319 			spin_lock(&ip->i_flags_lock);
2320 			if (ip->i_ino != inum + i ||
2321 			    __xfs_iflags_test(ip, XFS_ISTALE)) {
2322 				spin_unlock(&ip->i_flags_lock);
2323 				rcu_read_unlock();
2324 				continue;
2325 			}
2326 			spin_unlock(&ip->i_flags_lock);
2327 
2328 			/*
2329 			 * Don't try to lock/unlock the current inode, but we
2330 			 * _cannot_ skip the other inodes that we did not find
2331 			 * in the list attached to the buffer and are not
2332 			 * already marked stale. If we can't lock it, back off
2333 			 * and retry.
2334 			 */
2335 			if (ip != free_ip) {
2336 				if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
2337 					rcu_read_unlock();
2338 					delay(1);
2339 					goto retry;
2340 				}
2341 
2342 				/*
2343 				 * Check the inode number again in case we're
2344 				 * racing with freeing in xfs_reclaim_inode().
2345 				 * See the comments in that function for more
2346 				 * information as to why the initial check is
2347 				 * not sufficient.
2348 				 */
2349 				if (ip->i_ino != inum + i) {
2350 					xfs_iunlock(ip, XFS_ILOCK_EXCL);
2351 					rcu_read_unlock();
2352 					continue;
2353 				}
2354 			}
2355 			rcu_read_unlock();
2356 
2357 			xfs_iflock(ip);
2358 			xfs_iflags_set(ip, XFS_ISTALE);
2359 
2360 			/*
2361 			 * we don't need to attach clean inodes or those only
2362 			 * with unlogged changes (which we throw away, anyway).
2363 			 */
2364 			iip = ip->i_itemp;
2365 			if (!iip || xfs_inode_clean(ip)) {
2366 				ASSERT(ip != free_ip);
2367 				xfs_ifunlock(ip);
2368 				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2369 				continue;
2370 			}
2371 
2372 			iip->ili_last_fields = iip->ili_fields;
2373 			iip->ili_fields = 0;
2374 			iip->ili_fsync_fields = 0;
2375 			iip->ili_logged = 1;
2376 			xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
2377 						&iip->ili_item.li_lsn);
2378 
2379 			xfs_buf_attach_iodone(bp, xfs_istale_done,
2380 						  &iip->ili_item);
2381 
2382 			if (ip != free_ip)
2383 				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2384 		}
2385 
2386 		xfs_trans_stale_inode_buf(tp, bp);
2387 		xfs_trans_binval(tp, bp);
2388 	}
2389 
2390 	xfs_perag_put(pag);
2391 	return 0;
2392 }
2393 
2394 /*
2395  * Free any local-format buffers sitting around before we reset to
2396  * extents format.
2397  */
2398 static inline void
2399 xfs_ifree_local_data(
2400 	struct xfs_inode	*ip,
2401 	int			whichfork)
2402 {
2403 	struct xfs_ifork	*ifp;
2404 
2405 	if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL)
2406 		return;
2407 
2408 	ifp = XFS_IFORK_PTR(ip, whichfork);
2409 	xfs_idata_realloc(ip, -ifp->if_bytes, whichfork);
2410 }
2411 
2412 /*
2413  * This is called to return an inode to the inode free list.
2414  * The inode should already be truncated to 0 length and have
2415  * no pages associated with it.  This routine also assumes that
2416  * the inode is already a part of the transaction.
2417  *
2418  * The on-disk copy of the inode will have been added to the list
2419  * of unlinked inodes in the AGI. We need to remove the inode from
2420  * that list atomically with respect to freeing it here.
2421  */
2422 int
2423 xfs_ifree(
2424 	xfs_trans_t	*tp,
2425 	xfs_inode_t	*ip,
2426 	struct xfs_defer_ops	*dfops)
2427 {
2428 	int			error;
2429 	struct xfs_icluster	xic = { 0 };
2430 
2431 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
2432 	ASSERT(VFS_I(ip)->i_nlink == 0);
2433 	ASSERT(ip->i_d.di_nextents == 0);
2434 	ASSERT(ip->i_d.di_anextents == 0);
2435 	ASSERT(ip->i_d.di_size == 0 || !S_ISREG(VFS_I(ip)->i_mode));
2436 	ASSERT(ip->i_d.di_nblocks == 0);
2437 
2438 	/*
2439 	 * Pull the on-disk inode from the AGI unlinked list.
2440 	 */
2441 	error = xfs_iunlink_remove(tp, ip);
2442 	if (error)
2443 		return error;
2444 
2445 	error = xfs_difree(tp, ip->i_ino, dfops, &xic);
2446 	if (error)
2447 		return error;
2448 
2449 	xfs_ifree_local_data(ip, XFS_DATA_FORK);
2450 	xfs_ifree_local_data(ip, XFS_ATTR_FORK);
2451 
2452 	VFS_I(ip)->i_mode = 0;		/* mark incore inode as free */
2453 	ip->i_d.di_flags = 0;
2454 	ip->i_d.di_dmevmask = 0;
2455 	ip->i_d.di_forkoff = 0;		/* mark the attr fork not in use */
2456 	ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
2457 	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
2458 	/*
2459 	 * Bump the generation count so no one will be confused
2460 	 * by reincarnations of this inode.
2461 	 */
2462 	VFS_I(ip)->i_generation++;
2463 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2464 
2465 	if (xic.deleted)
2466 		error = xfs_ifree_cluster(ip, tp, &xic);
2467 
2468 	return error;
2469 }
2470 
2471 /*
2472  * This is called to unpin an inode.  The caller must have the inode locked
2473  * in at least shared mode so that the buffer cannot be subsequently pinned
2474  * once someone is waiting for it to be unpinned.
2475  */
2476 static void
2477 xfs_iunpin(
2478 	struct xfs_inode	*ip)
2479 {
2480 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
2481 
2482 	trace_xfs_inode_unpin_nowait(ip, _RET_IP_);
2483 
2484 	/* Give the log a push to start the unpinning I/O */
2485 	xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0);
2486 
2487 }
2488 
2489 static void
2490 __xfs_iunpin_wait(
2491 	struct xfs_inode	*ip)
2492 {
2493 	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IPINNED_BIT);
2494 	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IPINNED_BIT);
2495 
2496 	xfs_iunpin(ip);
2497 
2498 	do {
2499 		prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
2500 		if (xfs_ipincount(ip))
2501 			io_schedule();
2502 	} while (xfs_ipincount(ip));
2503 	finish_wait(wq, &wait.wq_entry);
2504 }
2505 
2506 void
2507 xfs_iunpin_wait(
2508 	struct xfs_inode	*ip)
2509 {
2510 	if (xfs_ipincount(ip))
2511 		__xfs_iunpin_wait(ip);
2512 }
2513 
2514 /*
2515  * Removing an inode from the namespace involves removing the directory entry
2516  * and dropping the link count on the inode. Removing the directory entry can
2517  * result in locking an AGF (directory blocks were freed) and removing a link
2518  * count can result in placing the inode on an unlinked list which results in
2519  * locking an AGI.
2520  *
2521  * The big problem here is that we have an ordering constraint on AGF and AGI
2522  * locking - inode allocation locks the AGI, then can allocate a new extent for
2523  * new inodes, locking the AGF after the AGI. Similarly, freeing the inode
2524  * removes the inode from the unlinked list, requiring that we lock the AGI
2525  * first, and then freeing the inode can result in an inode chunk being freed
2526  * and hence freeing disk space requiring that we lock an AGF.
2527  *
2528  * Hence the ordering that is imposed by other parts of the code is AGI before
2529  * AGF. This means we cannot remove the directory entry before we drop the inode
2530  * reference count and put it on the unlinked list as this results in a lock
2531  * order of AGF then AGI, and this can deadlock against inode allocation and
2532  * freeing. Therefore we must drop the link counts before we remove the
2533  * directory entry.
2534  *
2535  * This is still safe from a transactional point of view - it is not until we
2536  * get to xfs_defer_finish() that we have the possibility of multiple
2537  * transactions in this operation. Hence as long as we remove the directory
2538  * entry and drop the link count in the first transaction of the remove
2539  * operation, there are no transactional constraints on the ordering here.
2540  */
2541 int
2542 xfs_remove(
2543 	xfs_inode_t             *dp,
2544 	struct xfs_name		*name,
2545 	xfs_inode_t		*ip)
2546 {
2547 	xfs_mount_t		*mp = dp->i_mount;
2548 	xfs_trans_t             *tp = NULL;
2549 	int			is_dir = S_ISDIR(VFS_I(ip)->i_mode);
2550 	int                     error = 0;
2551 	struct xfs_defer_ops	dfops;
2552 	xfs_fsblock_t           first_block;
2553 	uint			resblks;
2554 
2555 	trace_xfs_remove(dp, name);
2556 
2557 	if (XFS_FORCED_SHUTDOWN(mp))
2558 		return -EIO;
2559 
2560 	error = xfs_qm_dqattach(dp, 0);
2561 	if (error)
2562 		goto std_return;
2563 
2564 	error = xfs_qm_dqattach(ip, 0);
2565 	if (error)
2566 		goto std_return;
2567 
2568 	/*
2569 	 * We try to get the real space reservation first,
2570 	 * allowing for directory btree deletion(s) implying
2571 	 * possible bmap insert(s).  If we can't get the space
2572 	 * reservation then we use 0 instead, and avoid the bmap
2573 	 * btree insert(s) in the directory code by, if the bmap
2574 	 * insert tries to happen, instead trimming the LAST
2575 	 * block from the directory.
2576 	 */
2577 	resblks = XFS_REMOVE_SPACE_RES(mp);
2578 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, resblks, 0, 0, &tp);
2579 	if (error == -ENOSPC) {
2580 		resblks = 0;
2581 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, 0, 0, 0,
2582 				&tp);
2583 	}
2584 	if (error) {
2585 		ASSERT(error != -ENOSPC);
2586 		goto std_return;
2587 	}
2588 
2589 	xfs_lock_two_inodes(dp, ip, XFS_ILOCK_EXCL);
2590 
2591 	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
2592 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
2593 
2594 	/*
2595 	 * If we're removing a directory perform some additional validation.
2596 	 */
2597 	if (is_dir) {
2598 		ASSERT(VFS_I(ip)->i_nlink >= 2);
2599 		if (VFS_I(ip)->i_nlink != 2) {
2600 			error = -ENOTEMPTY;
2601 			goto out_trans_cancel;
2602 		}
2603 		if (!xfs_dir_isempty(ip)) {
2604 			error = -ENOTEMPTY;
2605 			goto out_trans_cancel;
2606 		}
2607 
2608 		/* Drop the link from ip's "..".  */
2609 		error = xfs_droplink(tp, dp);
2610 		if (error)
2611 			goto out_trans_cancel;
2612 
2613 		/* Drop the "." link from ip to self.  */
2614 		error = xfs_droplink(tp, ip);
2615 		if (error)
2616 			goto out_trans_cancel;
2617 	} else {
2618 		/*
2619 		 * When removing a non-directory we need to log the parent
2620 		 * inode here.  For a directory this is done implicitly
2621 		 * by the xfs_droplink call for the ".." entry.
2622 		 */
2623 		xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
2624 	}
2625 	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2626 
2627 	/* Drop the link from dp to ip. */
2628 	error = xfs_droplink(tp, ip);
2629 	if (error)
2630 		goto out_trans_cancel;
2631 
2632 	xfs_defer_init(&dfops, &first_block);
2633 	error = xfs_dir_removename(tp, dp, name, ip->i_ino,
2634 					&first_block, &dfops, resblks);
2635 	if (error) {
2636 		ASSERT(error != -ENOENT);
2637 		goto out_bmap_cancel;
2638 	}
2639 
2640 	/*
2641 	 * If this is a synchronous mount, make sure that the
2642 	 * remove transaction goes to disk before returning to
2643 	 * the user.
2644 	 */
2645 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2646 		xfs_trans_set_sync(tp);
2647 
2648 	error = xfs_defer_finish(&tp, &dfops);
2649 	if (error)
2650 		goto out_bmap_cancel;
2651 
2652 	error = xfs_trans_commit(tp);
2653 	if (error)
2654 		goto std_return;
2655 
2656 	if (is_dir && xfs_inode_is_filestream(ip))
2657 		xfs_filestream_deassociate(ip);
2658 
2659 	return 0;
2660 
2661  out_bmap_cancel:
2662 	xfs_defer_cancel(&dfops);
2663  out_trans_cancel:
2664 	xfs_trans_cancel(tp);
2665  std_return:
2666 	return error;
2667 }
2668 
2669 /*
2670  * Enter all inodes for a rename transaction into a sorted array.
2671  */
2672 #define __XFS_SORT_INODES	5
2673 STATIC void
2674 xfs_sort_for_rename(
2675 	struct xfs_inode	*dp1,	/* in: old (source) directory inode */
2676 	struct xfs_inode	*dp2,	/* in: new (target) directory inode */
2677 	struct xfs_inode	*ip1,	/* in: inode of old entry */
2678 	struct xfs_inode	*ip2,	/* in: inode of new entry */
2679 	struct xfs_inode	*wip,	/* in: whiteout inode */
2680 	struct xfs_inode	**i_tab,/* out: sorted array of inodes */
2681 	int			*num_inodes)  /* in/out: inodes in array */
2682 {
2683 	int			i, j;
2684 
2685 	ASSERT(*num_inodes == __XFS_SORT_INODES);
2686 	memset(i_tab, 0, *num_inodes * sizeof(struct xfs_inode *));
2687 
2688 	/*
2689 	 * i_tab contains a list of pointers to inodes.  We initialize
2690 	 * the table here & we'll sort it.  We will then use it to
2691 	 * order the acquisition of the inode locks.
2692 	 *
2693 	 * Note that the table may contain duplicates.  e.g., dp1 == dp2.
2694 	 */
2695 	i = 0;
2696 	i_tab[i++] = dp1;
2697 	i_tab[i++] = dp2;
2698 	i_tab[i++] = ip1;
2699 	if (ip2)
2700 		i_tab[i++] = ip2;
2701 	if (wip)
2702 		i_tab[i++] = wip;
2703 	*num_inodes = i;
2704 
2705 	/*
2706 	 * Sort the elements via bubble sort.  (Remember, there are at
2707 	 * most 5 elements to sort, so this is adequate.)
2708 	 */
2709 	for (i = 0; i < *num_inodes; i++) {
2710 		for (j = 1; j < *num_inodes; j++) {
2711 			if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
2712 				struct xfs_inode *temp = i_tab[j];
2713 				i_tab[j] = i_tab[j-1];
2714 				i_tab[j-1] = temp;
2715 			}
2716 		}
2717 	}
2718 }
2719 
2720 static int
2721 xfs_finish_rename(
2722 	struct xfs_trans	*tp,
2723 	struct xfs_defer_ops	*dfops)
2724 {
2725 	int			error;
2726 
2727 	/*
2728 	 * If this is a synchronous mount, make sure that the rename transaction
2729 	 * goes to disk before returning to the user.
2730 	 */
2731 	if (tp->t_mountp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2732 		xfs_trans_set_sync(tp);
2733 
2734 	error = xfs_defer_finish(&tp, dfops);
2735 	if (error) {
2736 		xfs_defer_cancel(dfops);
2737 		xfs_trans_cancel(tp);
2738 		return error;
2739 	}
2740 
2741 	return xfs_trans_commit(tp);
2742 }
2743 
2744 /*
2745  * xfs_cross_rename()
2746  *
2747  * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall
2748  */
2749 STATIC int
2750 xfs_cross_rename(
2751 	struct xfs_trans	*tp,
2752 	struct xfs_inode	*dp1,
2753 	struct xfs_name		*name1,
2754 	struct xfs_inode	*ip1,
2755 	struct xfs_inode	*dp2,
2756 	struct xfs_name		*name2,
2757 	struct xfs_inode	*ip2,
2758 	struct xfs_defer_ops	*dfops,
2759 	xfs_fsblock_t		*first_block,
2760 	int			spaceres)
2761 {
2762 	int		error = 0;
2763 	int		ip1_flags = 0;
2764 	int		ip2_flags = 0;
2765 	int		dp2_flags = 0;
2766 
2767 	/* Swap inode number for dirent in first parent */
2768 	error = xfs_dir_replace(tp, dp1, name1,
2769 				ip2->i_ino,
2770 				first_block, dfops, spaceres);
2771 	if (error)
2772 		goto out_trans_abort;
2773 
2774 	/* Swap inode number for dirent in second parent */
2775 	error = xfs_dir_replace(tp, dp2, name2,
2776 				ip1->i_ino,
2777 				first_block, dfops, spaceres);
2778 	if (error)
2779 		goto out_trans_abort;
2780 
2781 	/*
2782 	 * If we're renaming one or more directories across different parents,
2783 	 * update the respective ".." entries (and link counts) to match the new
2784 	 * parents.
2785 	 */
2786 	if (dp1 != dp2) {
2787 		dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2788 
2789 		if (S_ISDIR(VFS_I(ip2)->i_mode)) {
2790 			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
2791 						dp1->i_ino, first_block,
2792 						dfops, spaceres);
2793 			if (error)
2794 				goto out_trans_abort;
2795 
2796 			/* transfer ip2 ".." reference to dp1 */
2797 			if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
2798 				error = xfs_droplink(tp, dp2);
2799 				if (error)
2800 					goto out_trans_abort;
2801 				error = xfs_bumplink(tp, dp1);
2802 				if (error)
2803 					goto out_trans_abort;
2804 			}
2805 
2806 			/*
2807 			 * Although ip1 isn't changed here, userspace needs
2808 			 * to be warned about the change, so that applications
2809 			 * relying on it (like backup ones), will properly
2810 			 * notify the change
2811 			 */
2812 			ip1_flags |= XFS_ICHGTIME_CHG;
2813 			ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2814 		}
2815 
2816 		if (S_ISDIR(VFS_I(ip1)->i_mode)) {
2817 			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
2818 						dp2->i_ino, first_block,
2819 						dfops, spaceres);
2820 			if (error)
2821 				goto out_trans_abort;
2822 
2823 			/* transfer ip1 ".." reference to dp2 */
2824 			if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
2825 				error = xfs_droplink(tp, dp1);
2826 				if (error)
2827 					goto out_trans_abort;
2828 				error = xfs_bumplink(tp, dp2);
2829 				if (error)
2830 					goto out_trans_abort;
2831 			}
2832 
2833 			/*
2834 			 * Although ip2 isn't changed here, userspace needs
2835 			 * to be warned about the change, so that applications
2836 			 * relying on it (like backup ones), will properly
2837 			 * notify the change
2838 			 */
2839 			ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2840 			ip2_flags |= XFS_ICHGTIME_CHG;
2841 		}
2842 	}
2843 
2844 	if (ip1_flags) {
2845 		xfs_trans_ichgtime(tp, ip1, ip1_flags);
2846 		xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
2847 	}
2848 	if (ip2_flags) {
2849 		xfs_trans_ichgtime(tp, ip2, ip2_flags);
2850 		xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
2851 	}
2852 	if (dp2_flags) {
2853 		xfs_trans_ichgtime(tp, dp2, dp2_flags);
2854 		xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
2855 	}
2856 	xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2857 	xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
2858 	return xfs_finish_rename(tp, dfops);
2859 
2860 out_trans_abort:
2861 	xfs_defer_cancel(dfops);
2862 	xfs_trans_cancel(tp);
2863 	return error;
2864 }
2865 
2866 /*
2867  * xfs_rename_alloc_whiteout()
2868  *
2869  * Return a referenced, unlinked, unlocked inode that that can be used as a
2870  * whiteout in a rename transaction. We use a tmpfile inode here so that if we
2871  * crash between allocating the inode and linking it into the rename transaction
2872  * recovery will free the inode and we won't leak it.
2873  */
2874 static int
2875 xfs_rename_alloc_whiteout(
2876 	struct xfs_inode	*dp,
2877 	struct xfs_inode	**wip)
2878 {
2879 	struct xfs_inode	*tmpfile;
2880 	int			error;
2881 
2882 	error = xfs_create_tmpfile(dp, NULL, S_IFCHR | WHITEOUT_MODE, &tmpfile);
2883 	if (error)
2884 		return error;
2885 
2886 	/*
2887 	 * Prepare the tmpfile inode as if it were created through the VFS.
2888 	 * Otherwise, the link increment paths will complain about nlink 0->1.
2889 	 * Drop the link count as done by d_tmpfile(), complete the inode setup
2890 	 * and flag it as linkable.
2891 	 */
2892 	drop_nlink(VFS_I(tmpfile));
2893 	xfs_setup_iops(tmpfile);
2894 	xfs_finish_inode_setup(tmpfile);
2895 	VFS_I(tmpfile)->i_state |= I_LINKABLE;
2896 
2897 	*wip = tmpfile;
2898 	return 0;
2899 }
2900 
2901 /*
2902  * xfs_rename
2903  */
2904 int
2905 xfs_rename(
2906 	struct xfs_inode	*src_dp,
2907 	struct xfs_name		*src_name,
2908 	struct xfs_inode	*src_ip,
2909 	struct xfs_inode	*target_dp,
2910 	struct xfs_name		*target_name,
2911 	struct xfs_inode	*target_ip,
2912 	unsigned int		flags)
2913 {
2914 	struct xfs_mount	*mp = src_dp->i_mount;
2915 	struct xfs_trans	*tp;
2916 	struct xfs_defer_ops	dfops;
2917 	xfs_fsblock_t		first_block;
2918 	struct xfs_inode	*wip = NULL;		/* whiteout inode */
2919 	struct xfs_inode	*inodes[__XFS_SORT_INODES];
2920 	int			num_inodes = __XFS_SORT_INODES;
2921 	bool			new_parent = (src_dp != target_dp);
2922 	bool			src_is_directory = S_ISDIR(VFS_I(src_ip)->i_mode);
2923 	int			spaceres;
2924 	int			error;
2925 
2926 	trace_xfs_rename(src_dp, target_dp, src_name, target_name);
2927 
2928 	if ((flags & RENAME_EXCHANGE) && !target_ip)
2929 		return -EINVAL;
2930 
2931 	/*
2932 	 * If we are doing a whiteout operation, allocate the whiteout inode
2933 	 * we will be placing at the target and ensure the type is set
2934 	 * appropriately.
2935 	 */
2936 	if (flags & RENAME_WHITEOUT) {
2937 		ASSERT(!(flags & (RENAME_NOREPLACE | RENAME_EXCHANGE)));
2938 		error = xfs_rename_alloc_whiteout(target_dp, &wip);
2939 		if (error)
2940 			return error;
2941 
2942 		/* setup target dirent info as whiteout */
2943 		src_name->type = XFS_DIR3_FT_CHRDEV;
2944 	}
2945 
2946 	xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip, wip,
2947 				inodes, &num_inodes);
2948 
2949 	spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
2950 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, spaceres, 0, 0, &tp);
2951 	if (error == -ENOSPC) {
2952 		spaceres = 0;
2953 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, 0, 0, 0,
2954 				&tp);
2955 	}
2956 	if (error)
2957 		goto out_release_wip;
2958 
2959 	/*
2960 	 * Attach the dquots to the inodes
2961 	 */
2962 	error = xfs_qm_vop_rename_dqattach(inodes);
2963 	if (error)
2964 		goto out_trans_cancel;
2965 
2966 	/*
2967 	 * Lock all the participating inodes. Depending upon whether
2968 	 * the target_name exists in the target directory, and
2969 	 * whether the target directory is the same as the source
2970 	 * directory, we can lock from 2 to 4 inodes.
2971 	 */
2972 	xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
2973 
2974 	/*
2975 	 * Join all the inodes to the transaction. From this point on,
2976 	 * we can rely on either trans_commit or trans_cancel to unlock
2977 	 * them.
2978 	 */
2979 	xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
2980 	if (new_parent)
2981 		xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
2982 	xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
2983 	if (target_ip)
2984 		xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
2985 	if (wip)
2986 		xfs_trans_ijoin(tp, wip, XFS_ILOCK_EXCL);
2987 
2988 	/*
2989 	 * If we are using project inheritance, we only allow renames
2990 	 * into our tree when the project IDs are the same; else the
2991 	 * tree quota mechanism would be circumvented.
2992 	 */
2993 	if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
2994 		     (xfs_get_projid(target_dp) != xfs_get_projid(src_ip)))) {
2995 		error = -EXDEV;
2996 		goto out_trans_cancel;
2997 	}
2998 
2999 	xfs_defer_init(&dfops, &first_block);
3000 
3001 	/* RENAME_EXCHANGE is unique from here on. */
3002 	if (flags & RENAME_EXCHANGE)
3003 		return xfs_cross_rename(tp, src_dp, src_name, src_ip,
3004 					target_dp, target_name, target_ip,
3005 					&dfops, &first_block, spaceres);
3006 
3007 	/*
3008 	 * Set up the target.
3009 	 */
3010 	if (target_ip == NULL) {
3011 		/*
3012 		 * If there's no space reservation, check the entry will
3013 		 * fit before actually inserting it.
3014 		 */
3015 		if (!spaceres) {
3016 			error = xfs_dir_canenter(tp, target_dp, target_name);
3017 			if (error)
3018 				goto out_trans_cancel;
3019 		}
3020 		/*
3021 		 * If target does not exist and the rename crosses
3022 		 * directories, adjust the target directory link count
3023 		 * to account for the ".." reference from the new entry.
3024 		 */
3025 		error = xfs_dir_createname(tp, target_dp, target_name,
3026 						src_ip->i_ino, &first_block,
3027 						&dfops, spaceres);
3028 		if (error)
3029 			goto out_bmap_cancel;
3030 
3031 		xfs_trans_ichgtime(tp, target_dp,
3032 					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3033 
3034 		if (new_parent && src_is_directory) {
3035 			error = xfs_bumplink(tp, target_dp);
3036 			if (error)
3037 				goto out_bmap_cancel;
3038 		}
3039 	} else { /* target_ip != NULL */
3040 		/*
3041 		 * If target exists and it's a directory, check that both
3042 		 * target and source are directories and that target can be
3043 		 * destroyed, or that neither is a directory.
3044 		 */
3045 		if (S_ISDIR(VFS_I(target_ip)->i_mode)) {
3046 			/*
3047 			 * Make sure target dir is empty.
3048 			 */
3049 			if (!(xfs_dir_isempty(target_ip)) ||
3050 			    (VFS_I(target_ip)->i_nlink > 2)) {
3051 				error = -EEXIST;
3052 				goto out_trans_cancel;
3053 			}
3054 		}
3055 
3056 		/*
3057 		 * Link the source inode under the target name.
3058 		 * If the source inode is a directory and we are moving
3059 		 * it across directories, its ".." entry will be
3060 		 * inconsistent until we replace that down below.
3061 		 *
3062 		 * In case there is already an entry with the same
3063 		 * name at the destination directory, remove it first.
3064 		 */
3065 		error = xfs_dir_replace(tp, target_dp, target_name,
3066 					src_ip->i_ino,
3067 					&first_block, &dfops, spaceres);
3068 		if (error)
3069 			goto out_bmap_cancel;
3070 
3071 		xfs_trans_ichgtime(tp, target_dp,
3072 					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3073 
3074 		/*
3075 		 * Decrement the link count on the target since the target
3076 		 * dir no longer points to it.
3077 		 */
3078 		error = xfs_droplink(tp, target_ip);
3079 		if (error)
3080 			goto out_bmap_cancel;
3081 
3082 		if (src_is_directory) {
3083 			/*
3084 			 * Drop the link from the old "." entry.
3085 			 */
3086 			error = xfs_droplink(tp, target_ip);
3087 			if (error)
3088 				goto out_bmap_cancel;
3089 		}
3090 	} /* target_ip != NULL */
3091 
3092 	/*
3093 	 * Remove the source.
3094 	 */
3095 	if (new_parent && src_is_directory) {
3096 		/*
3097 		 * Rewrite the ".." entry to point to the new
3098 		 * directory.
3099 		 */
3100 		error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
3101 					target_dp->i_ino,
3102 					&first_block, &dfops, spaceres);
3103 		ASSERT(error != -EEXIST);
3104 		if (error)
3105 			goto out_bmap_cancel;
3106 	}
3107 
3108 	/*
3109 	 * We always want to hit the ctime on the source inode.
3110 	 *
3111 	 * This isn't strictly required by the standards since the source
3112 	 * inode isn't really being changed, but old unix file systems did
3113 	 * it and some incremental backup programs won't work without it.
3114 	 */
3115 	xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
3116 	xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
3117 
3118 	/*
3119 	 * Adjust the link count on src_dp.  This is necessary when
3120 	 * renaming a directory, either within one parent when
3121 	 * the target existed, or across two parent directories.
3122 	 */
3123 	if (src_is_directory && (new_parent || target_ip != NULL)) {
3124 
3125 		/*
3126 		 * Decrement link count on src_directory since the
3127 		 * entry that's moved no longer points to it.
3128 		 */
3129 		error = xfs_droplink(tp, src_dp);
3130 		if (error)
3131 			goto out_bmap_cancel;
3132 	}
3133 
3134 	/*
3135 	 * For whiteouts, we only need to update the source dirent with the
3136 	 * inode number of the whiteout inode rather than removing it
3137 	 * altogether.
3138 	 */
3139 	if (wip) {
3140 		error = xfs_dir_replace(tp, src_dp, src_name, wip->i_ino,
3141 					&first_block, &dfops, spaceres);
3142 	} else
3143 		error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
3144 					   &first_block, &dfops, spaceres);
3145 	if (error)
3146 		goto out_bmap_cancel;
3147 
3148 	/*
3149 	 * For whiteouts, we need to bump the link count on the whiteout inode.
3150 	 * This means that failures all the way up to this point leave the inode
3151 	 * on the unlinked list and so cleanup is a simple matter of dropping
3152 	 * the remaining reference to it. If we fail here after bumping the link
3153 	 * count, we're shutting down the filesystem so we'll never see the
3154 	 * intermediate state on disk.
3155 	 */
3156 	if (wip) {
3157 		ASSERT(VFS_I(wip)->i_nlink == 0);
3158 		error = xfs_bumplink(tp, wip);
3159 		if (error)
3160 			goto out_bmap_cancel;
3161 		error = xfs_iunlink_remove(tp, wip);
3162 		if (error)
3163 			goto out_bmap_cancel;
3164 		xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE);
3165 
3166 		/*
3167 		 * Now we have a real link, clear the "I'm a tmpfile" state
3168 		 * flag from the inode so it doesn't accidentally get misused in
3169 		 * future.
3170 		 */
3171 		VFS_I(wip)->i_state &= ~I_LINKABLE;
3172 	}
3173 
3174 	xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3175 	xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
3176 	if (new_parent)
3177 		xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
3178 
3179 	error = xfs_finish_rename(tp, &dfops);
3180 	if (wip)
3181 		IRELE(wip);
3182 	return error;
3183 
3184 out_bmap_cancel:
3185 	xfs_defer_cancel(&dfops);
3186 out_trans_cancel:
3187 	xfs_trans_cancel(tp);
3188 out_release_wip:
3189 	if (wip)
3190 		IRELE(wip);
3191 	return error;
3192 }
3193 
3194 STATIC int
3195 xfs_iflush_cluster(
3196 	struct xfs_inode	*ip,
3197 	struct xfs_buf		*bp)
3198 {
3199 	struct xfs_mount	*mp = ip->i_mount;
3200 	struct xfs_perag	*pag;
3201 	unsigned long		first_index, mask;
3202 	unsigned long		inodes_per_cluster;
3203 	int			cilist_size;
3204 	struct xfs_inode	**cilist;
3205 	struct xfs_inode	*cip;
3206 	int			nr_found;
3207 	int			clcount = 0;
3208 	int			bufwasdelwri;
3209 	int			i;
3210 
3211 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
3212 
3213 	inodes_per_cluster = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;
3214 	cilist_size = inodes_per_cluster * sizeof(xfs_inode_t *);
3215 	cilist = kmem_alloc(cilist_size, KM_MAYFAIL|KM_NOFS);
3216 	if (!cilist)
3217 		goto out_put;
3218 
3219 	mask = ~(((mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog)) - 1);
3220 	first_index = XFS_INO_TO_AGINO(mp, ip->i_ino) & mask;
3221 	rcu_read_lock();
3222 	/* really need a gang lookup range call here */
3223 	nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void**)cilist,
3224 					first_index, inodes_per_cluster);
3225 	if (nr_found == 0)
3226 		goto out_free;
3227 
3228 	for (i = 0; i < nr_found; i++) {
3229 		cip = cilist[i];
3230 		if (cip == ip)
3231 			continue;
3232 
3233 		/*
3234 		 * because this is an RCU protected lookup, we could find a
3235 		 * recently freed or even reallocated inode during the lookup.
3236 		 * We need to check under the i_flags_lock for a valid inode
3237 		 * here. Skip it if it is not valid or the wrong inode.
3238 		 */
3239 		spin_lock(&cip->i_flags_lock);
3240 		if (!cip->i_ino ||
3241 		    __xfs_iflags_test(cip, XFS_ISTALE)) {
3242 			spin_unlock(&cip->i_flags_lock);
3243 			continue;
3244 		}
3245 
3246 		/*
3247 		 * Once we fall off the end of the cluster, no point checking
3248 		 * any more inodes in the list because they will also all be
3249 		 * outside the cluster.
3250 		 */
3251 		if ((XFS_INO_TO_AGINO(mp, cip->i_ino) & mask) != first_index) {
3252 			spin_unlock(&cip->i_flags_lock);
3253 			break;
3254 		}
3255 		spin_unlock(&cip->i_flags_lock);
3256 
3257 		/*
3258 		 * Do an un-protected check to see if the inode is dirty and
3259 		 * is a candidate for flushing.  These checks will be repeated
3260 		 * later after the appropriate locks are acquired.
3261 		 */
3262 		if (xfs_inode_clean(cip) && xfs_ipincount(cip) == 0)
3263 			continue;
3264 
3265 		/*
3266 		 * Try to get locks.  If any are unavailable or it is pinned,
3267 		 * then this inode cannot be flushed and is skipped.
3268 		 */
3269 
3270 		if (!xfs_ilock_nowait(cip, XFS_ILOCK_SHARED))
3271 			continue;
3272 		if (!xfs_iflock_nowait(cip)) {
3273 			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3274 			continue;
3275 		}
3276 		if (xfs_ipincount(cip)) {
3277 			xfs_ifunlock(cip);
3278 			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3279 			continue;
3280 		}
3281 
3282 
3283 		/*
3284 		 * Check the inode number again, just to be certain we are not
3285 		 * racing with freeing in xfs_reclaim_inode(). See the comments
3286 		 * in that function for more information as to why the initial
3287 		 * check is not sufficient.
3288 		 */
3289 		if (!cip->i_ino) {
3290 			xfs_ifunlock(cip);
3291 			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3292 			continue;
3293 		}
3294 
3295 		/*
3296 		 * arriving here means that this inode can be flushed.  First
3297 		 * re-check that it's dirty before flushing.
3298 		 */
3299 		if (!xfs_inode_clean(cip)) {
3300 			int	error;
3301 			error = xfs_iflush_int(cip, bp);
3302 			if (error) {
3303 				xfs_iunlock(cip, XFS_ILOCK_SHARED);
3304 				goto cluster_corrupt_out;
3305 			}
3306 			clcount++;
3307 		} else {
3308 			xfs_ifunlock(cip);
3309 		}
3310 		xfs_iunlock(cip, XFS_ILOCK_SHARED);
3311 	}
3312 
3313 	if (clcount) {
3314 		XFS_STATS_INC(mp, xs_icluster_flushcnt);
3315 		XFS_STATS_ADD(mp, xs_icluster_flushinode, clcount);
3316 	}
3317 
3318 out_free:
3319 	rcu_read_unlock();
3320 	kmem_free(cilist);
3321 out_put:
3322 	xfs_perag_put(pag);
3323 	return 0;
3324 
3325 
3326 cluster_corrupt_out:
3327 	/*
3328 	 * Corruption detected in the clustering loop.  Invalidate the
3329 	 * inode buffer and shut down the filesystem.
3330 	 */
3331 	rcu_read_unlock();
3332 	/*
3333 	 * Clean up the buffer.  If it was delwri, just release it --
3334 	 * brelse can handle it with no problems.  If not, shut down the
3335 	 * filesystem before releasing the buffer.
3336 	 */
3337 	bufwasdelwri = (bp->b_flags & _XBF_DELWRI_Q);
3338 	if (bufwasdelwri)
3339 		xfs_buf_relse(bp);
3340 
3341 	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3342 
3343 	if (!bufwasdelwri) {
3344 		/*
3345 		 * Just like incore_relse: if we have b_iodone functions,
3346 		 * mark the buffer as an error and call them.  Otherwise
3347 		 * mark it as stale and brelse.
3348 		 */
3349 		if (bp->b_iodone) {
3350 			bp->b_flags &= ~XBF_DONE;
3351 			xfs_buf_stale(bp);
3352 			xfs_buf_ioerror(bp, -EIO);
3353 			xfs_buf_ioend(bp);
3354 		} else {
3355 			xfs_buf_stale(bp);
3356 			xfs_buf_relse(bp);
3357 		}
3358 	}
3359 
3360 	/*
3361 	 * Unlocks the flush lock
3362 	 */
3363 	xfs_iflush_abort(cip, false);
3364 	kmem_free(cilist);
3365 	xfs_perag_put(pag);
3366 	return -EFSCORRUPTED;
3367 }
3368 
3369 /*
3370  * Flush dirty inode metadata into the backing buffer.
3371  *
3372  * The caller must have the inode lock and the inode flush lock held.  The
3373  * inode lock will still be held upon return to the caller, and the inode
3374  * flush lock will be released after the inode has reached the disk.
3375  *
3376  * The caller must write out the buffer returned in *bpp and release it.
3377  */
3378 int
3379 xfs_iflush(
3380 	struct xfs_inode	*ip,
3381 	struct xfs_buf		**bpp)
3382 {
3383 	struct xfs_mount	*mp = ip->i_mount;
3384 	struct xfs_buf		*bp = NULL;
3385 	struct xfs_dinode	*dip;
3386 	int			error;
3387 
3388 	XFS_STATS_INC(mp, xs_iflush_count);
3389 
3390 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3391 	ASSERT(xfs_isiflocked(ip));
3392 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3393 	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3394 
3395 	*bpp = NULL;
3396 
3397 	xfs_iunpin_wait(ip);
3398 
3399 	/*
3400 	 * For stale inodes we cannot rely on the backing buffer remaining
3401 	 * stale in cache for the remaining life of the stale inode and so
3402 	 * xfs_imap_to_bp() below may give us a buffer that no longer contains
3403 	 * inodes below. We have to check this after ensuring the inode is
3404 	 * unpinned so that it is safe to reclaim the stale inode after the
3405 	 * flush call.
3406 	 */
3407 	if (xfs_iflags_test(ip, XFS_ISTALE)) {
3408 		xfs_ifunlock(ip);
3409 		return 0;
3410 	}
3411 
3412 	/*
3413 	 * This may have been unpinned because the filesystem is shutting
3414 	 * down forcibly. If that's the case we must not write this inode
3415 	 * to disk, because the log record didn't make it to disk.
3416 	 *
3417 	 * We also have to remove the log item from the AIL in this case,
3418 	 * as we wait for an empty AIL as part of the unmount process.
3419 	 */
3420 	if (XFS_FORCED_SHUTDOWN(mp)) {
3421 		error = -EIO;
3422 		goto abort_out;
3423 	}
3424 
3425 	/*
3426 	 * Get the buffer containing the on-disk inode. We are doing a try-lock
3427 	 * operation here, so we may get  an EAGAIN error. In that case, we
3428 	 * simply want to return with the inode still dirty.
3429 	 *
3430 	 * If we get any other error, we effectively have a corruption situation
3431 	 * and we cannot flush the inode, so we treat it the same as failing
3432 	 * xfs_iflush_int().
3433 	 */
3434 	error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, XBF_TRYLOCK,
3435 			       0);
3436 	if (error == -EAGAIN) {
3437 		xfs_ifunlock(ip);
3438 		return error;
3439 	}
3440 	if (error)
3441 		goto corrupt_out;
3442 
3443 	/*
3444 	 * First flush out the inode that xfs_iflush was called with.
3445 	 */
3446 	error = xfs_iflush_int(ip, bp);
3447 	if (error)
3448 		goto corrupt_out;
3449 
3450 	/*
3451 	 * If the buffer is pinned then push on the log now so we won't
3452 	 * get stuck waiting in the write for too long.
3453 	 */
3454 	if (xfs_buf_ispinned(bp))
3455 		xfs_log_force(mp, 0);
3456 
3457 	/*
3458 	 * inode clustering:
3459 	 * see if other inodes can be gathered into this write
3460 	 */
3461 	error = xfs_iflush_cluster(ip, bp);
3462 	if (error)
3463 		goto cluster_corrupt_out;
3464 
3465 	*bpp = bp;
3466 	return 0;
3467 
3468 corrupt_out:
3469 	if (bp)
3470 		xfs_buf_relse(bp);
3471 	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3472 cluster_corrupt_out:
3473 	error = -EFSCORRUPTED;
3474 abort_out:
3475 	/*
3476 	 * Unlocks the flush lock
3477 	 */
3478 	xfs_iflush_abort(ip, false);
3479 	return error;
3480 }
3481 
3482 STATIC int
3483 xfs_iflush_int(
3484 	struct xfs_inode	*ip,
3485 	struct xfs_buf		*bp)
3486 {
3487 	struct xfs_inode_log_item *iip = ip->i_itemp;
3488 	struct xfs_dinode	*dip;
3489 	struct xfs_mount	*mp = ip->i_mount;
3490 
3491 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3492 	ASSERT(xfs_isiflocked(ip));
3493 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3494 	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3495 	ASSERT(iip != NULL && iip->ili_fields != 0);
3496 	ASSERT(ip->i_d.di_version > 1);
3497 
3498 	/* set *dip = inode's place in the buffer */
3499 	dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);
3500 
3501 	if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
3502 			       mp, XFS_ERRTAG_IFLUSH_1)) {
3503 		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3504 			"%s: Bad inode %Lu magic number 0x%x, ptr 0x%p",
3505 			__func__, ip->i_ino, be16_to_cpu(dip->di_magic), dip);
3506 		goto corrupt_out;
3507 	}
3508 	if (S_ISREG(VFS_I(ip)->i_mode)) {
3509 		if (XFS_TEST_ERROR(
3510 		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3511 		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
3512 		    mp, XFS_ERRTAG_IFLUSH_3)) {
3513 			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3514 				"%s: Bad regular inode %Lu, ptr 0x%p",
3515 				__func__, ip->i_ino, ip);
3516 			goto corrupt_out;
3517 		}
3518 	} else if (S_ISDIR(VFS_I(ip)->i_mode)) {
3519 		if (XFS_TEST_ERROR(
3520 		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3521 		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
3522 		    (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
3523 		    mp, XFS_ERRTAG_IFLUSH_4)) {
3524 			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3525 				"%s: Bad directory inode %Lu, ptr 0x%p",
3526 				__func__, ip->i_ino, ip);
3527 			goto corrupt_out;
3528 		}
3529 	}
3530 	if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
3531 				ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5)) {
3532 		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3533 			"%s: detected corrupt incore inode %Lu, "
3534 			"total extents = %d, nblocks = %Ld, ptr 0x%p",
3535 			__func__, ip->i_ino,
3536 			ip->i_d.di_nextents + ip->i_d.di_anextents,
3537 			ip->i_d.di_nblocks, ip);
3538 		goto corrupt_out;
3539 	}
3540 	if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
3541 				mp, XFS_ERRTAG_IFLUSH_6)) {
3542 		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3543 			"%s: bad inode %Lu, forkoff 0x%x, ptr 0x%p",
3544 			__func__, ip->i_ino, ip->i_d.di_forkoff, ip);
3545 		goto corrupt_out;
3546 	}
3547 
3548 	/*
3549 	 * Inode item log recovery for v2 inodes are dependent on the
3550 	 * di_flushiter count for correct sequencing. We bump the flush
3551 	 * iteration count so we can detect flushes which postdate a log record
3552 	 * during recovery. This is redundant as we now log every change and
3553 	 * hence this can't happen but we need to still do it to ensure
3554 	 * backwards compatibility with old kernels that predate logging all
3555 	 * inode changes.
3556 	 */
3557 	if (ip->i_d.di_version < 3)
3558 		ip->i_d.di_flushiter++;
3559 
3560 	/* Check the inline directory data. */
3561 	if (S_ISDIR(VFS_I(ip)->i_mode) &&
3562 	    ip->i_d.di_format == XFS_DINODE_FMT_LOCAL &&
3563 	    xfs_dir2_sf_verify(ip))
3564 		goto corrupt_out;
3565 
3566 	/*
3567 	 * Copy the dirty parts of the inode into the on-disk inode.  We always
3568 	 * copy out the core of the inode, because if the inode is dirty at all
3569 	 * the core must be.
3570 	 */
3571 	xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);
3572 
3573 	/* Wrap, we never let the log put out DI_MAX_FLUSH */
3574 	if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
3575 		ip->i_d.di_flushiter = 0;
3576 
3577 	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
3578 	if (XFS_IFORK_Q(ip))
3579 		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
3580 	xfs_inobp_check(mp, bp);
3581 
3582 	/*
3583 	 * We've recorded everything logged in the inode, so we'd like to clear
3584 	 * the ili_fields bits so we don't log and flush things unnecessarily.
3585 	 * However, we can't stop logging all this information until the data
3586 	 * we've copied into the disk buffer is written to disk.  If we did we
3587 	 * might overwrite the copy of the inode in the log with all the data
3588 	 * after re-logging only part of it, and in the face of a crash we
3589 	 * wouldn't have all the data we need to recover.
3590 	 *
3591 	 * What we do is move the bits to the ili_last_fields field.  When
3592 	 * logging the inode, these bits are moved back to the ili_fields field.
3593 	 * In the xfs_iflush_done() routine we clear ili_last_fields, since we
3594 	 * know that the information those bits represent is permanently on
3595 	 * disk.  As long as the flush completes before the inode is logged
3596 	 * again, then both ili_fields and ili_last_fields will be cleared.
3597 	 *
3598 	 * We can play with the ili_fields bits here, because the inode lock
3599 	 * must be held exclusively in order to set bits there and the flush
3600 	 * lock protects the ili_last_fields bits.  Set ili_logged so the flush
3601 	 * done routine can tell whether or not to look in the AIL.  Also, store
3602 	 * the current LSN of the inode so that we can tell whether the item has
3603 	 * moved in the AIL from xfs_iflush_done().  In order to read the lsn we
3604 	 * need the AIL lock, because it is a 64 bit value that cannot be read
3605 	 * atomically.
3606 	 */
3607 	iip->ili_last_fields = iip->ili_fields;
3608 	iip->ili_fields = 0;
3609 	iip->ili_fsync_fields = 0;
3610 	iip->ili_logged = 1;
3611 
3612 	xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
3613 				&iip->ili_item.li_lsn);
3614 
3615 	/*
3616 	 * Attach the function xfs_iflush_done to the inode's
3617 	 * buffer.  This will remove the inode from the AIL
3618 	 * and unlock the inode's flush lock when the inode is
3619 	 * completely written to disk.
3620 	 */
3621 	xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);
3622 
3623 	/* generate the checksum. */
3624 	xfs_dinode_calc_crc(mp, dip);
3625 
3626 	ASSERT(bp->b_fspriv != NULL);
3627 	ASSERT(bp->b_iodone != NULL);
3628 	return 0;
3629 
3630 corrupt_out:
3631 	return -EFSCORRUPTED;
3632 }
3633