xref: /linux/fs/xfs/xfs_inode.c (revision ef69f8d2ff09518657c3ecaf2db8408c16549829)
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 	int		okalloc,
753 	xfs_buf_t	**ialloc_context,
754 	xfs_inode_t	**ipp)
755 {
756 	struct xfs_mount *mp = tp->t_mountp;
757 	xfs_ino_t	ino;
758 	xfs_inode_t	*ip;
759 	uint		flags;
760 	int		error;
761 	struct timespec	tv;
762 	struct inode	*inode;
763 
764 	/*
765 	 * Call the space management code to pick
766 	 * the on-disk inode to be allocated.
767 	 */
768 	error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode, okalloc,
769 			    ialloc_context, &ino);
770 	if (error)
771 		return error;
772 	if (*ialloc_context || ino == NULLFSINO) {
773 		*ipp = NULL;
774 		return 0;
775 	}
776 	ASSERT(*ialloc_context == NULL);
777 
778 	/*
779 	 * Get the in-core inode with the lock held exclusively.
780 	 * This is because we're setting fields here we need
781 	 * to prevent others from looking at until we're done.
782 	 */
783 	error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE,
784 			 XFS_ILOCK_EXCL, &ip);
785 	if (error)
786 		return error;
787 	ASSERT(ip != NULL);
788 	inode = VFS_I(ip);
789 
790 	/*
791 	 * We always convert v1 inodes to v2 now - we only support filesystems
792 	 * with >= v2 inode capability, so there is no reason for ever leaving
793 	 * an inode in v1 format.
794 	 */
795 	if (ip->i_d.di_version == 1)
796 		ip->i_d.di_version = 2;
797 
798 	inode->i_mode = mode;
799 	set_nlink(inode, nlink);
800 	ip->i_d.di_uid = xfs_kuid_to_uid(current_fsuid());
801 	ip->i_d.di_gid = xfs_kgid_to_gid(current_fsgid());
802 	inode->i_rdev = rdev;
803 	xfs_set_projid(ip, prid);
804 
805 	if (pip && XFS_INHERIT_GID(pip)) {
806 		ip->i_d.di_gid = pip->i_d.di_gid;
807 		if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode))
808 			inode->i_mode |= S_ISGID;
809 	}
810 
811 	/*
812 	 * If the group ID of the new file does not match the effective group
813 	 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
814 	 * (and only if the irix_sgid_inherit compatibility variable is set).
815 	 */
816 	if ((irix_sgid_inherit) &&
817 	    (inode->i_mode & S_ISGID) &&
818 	    (!in_group_p(xfs_gid_to_kgid(ip->i_d.di_gid))))
819 		inode->i_mode &= ~S_ISGID;
820 
821 	ip->i_d.di_size = 0;
822 	ip->i_d.di_nextents = 0;
823 	ASSERT(ip->i_d.di_nblocks == 0);
824 
825 	tv = current_time(inode);
826 	inode->i_mtime = tv;
827 	inode->i_atime = tv;
828 	inode->i_ctime = tv;
829 
830 	ip->i_d.di_extsize = 0;
831 	ip->i_d.di_dmevmask = 0;
832 	ip->i_d.di_dmstate = 0;
833 	ip->i_d.di_flags = 0;
834 
835 	if (ip->i_d.di_version == 3) {
836 		inode->i_version = 1;
837 		ip->i_d.di_flags2 = 0;
838 		ip->i_d.di_cowextsize = 0;
839 		ip->i_d.di_crtime.t_sec = (int32_t)tv.tv_sec;
840 		ip->i_d.di_crtime.t_nsec = (int32_t)tv.tv_nsec;
841 	}
842 
843 
844 	flags = XFS_ILOG_CORE;
845 	switch (mode & S_IFMT) {
846 	case S_IFIFO:
847 	case S_IFCHR:
848 	case S_IFBLK:
849 	case S_IFSOCK:
850 		ip->i_d.di_format = XFS_DINODE_FMT_DEV;
851 		ip->i_df.if_flags = 0;
852 		flags |= XFS_ILOG_DEV;
853 		break;
854 	case S_IFREG:
855 	case S_IFDIR:
856 		if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
857 			uint		di_flags = 0;
858 
859 			if (S_ISDIR(mode)) {
860 				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
861 					di_flags |= XFS_DIFLAG_RTINHERIT;
862 				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
863 					di_flags |= XFS_DIFLAG_EXTSZINHERIT;
864 					ip->i_d.di_extsize = pip->i_d.di_extsize;
865 				}
866 				if (pip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
867 					di_flags |= XFS_DIFLAG_PROJINHERIT;
868 			} else if (S_ISREG(mode)) {
869 				if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
870 					di_flags |= XFS_DIFLAG_REALTIME;
871 				if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
872 					di_flags |= XFS_DIFLAG_EXTSIZE;
873 					ip->i_d.di_extsize = pip->i_d.di_extsize;
874 				}
875 			}
876 			if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
877 			    xfs_inherit_noatime)
878 				di_flags |= XFS_DIFLAG_NOATIME;
879 			if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
880 			    xfs_inherit_nodump)
881 				di_flags |= XFS_DIFLAG_NODUMP;
882 			if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
883 			    xfs_inherit_sync)
884 				di_flags |= XFS_DIFLAG_SYNC;
885 			if ((pip->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) &&
886 			    xfs_inherit_nosymlinks)
887 				di_flags |= XFS_DIFLAG_NOSYMLINKS;
888 			if ((pip->i_d.di_flags & XFS_DIFLAG_NODEFRAG) &&
889 			    xfs_inherit_nodefrag)
890 				di_flags |= XFS_DIFLAG_NODEFRAG;
891 			if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
892 				di_flags |= XFS_DIFLAG_FILESTREAM;
893 
894 			ip->i_d.di_flags |= di_flags;
895 		}
896 		if (pip &&
897 		    (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY) &&
898 		    pip->i_d.di_version == 3 &&
899 		    ip->i_d.di_version == 3) {
900 			uint64_t	di_flags2 = 0;
901 
902 			if (pip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) {
903 				di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
904 				ip->i_d.di_cowextsize = pip->i_d.di_cowextsize;
905 			}
906 			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
907 				di_flags2 |= XFS_DIFLAG2_DAX;
908 
909 			ip->i_d.di_flags2 |= di_flags2;
910 		}
911 		/* FALLTHROUGH */
912 	case S_IFLNK:
913 		ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
914 		ip->i_df.if_flags = XFS_IFEXTENTS;
915 		ip->i_df.if_bytes = ip->i_df.if_real_bytes = 0;
916 		ip->i_df.if_u1.if_root = NULL;
917 		break;
918 	default:
919 		ASSERT(0);
920 	}
921 	/*
922 	 * Attribute fork settings for new inode.
923 	 */
924 	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
925 	ip->i_d.di_anextents = 0;
926 
927 	/*
928 	 * Log the new values stuffed into the inode.
929 	 */
930 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
931 	xfs_trans_log_inode(tp, ip, flags);
932 
933 	/* now that we have an i_mode we can setup the inode structure */
934 	xfs_setup_inode(ip);
935 
936 	*ipp = ip;
937 	return 0;
938 }
939 
940 /*
941  * Allocates a new inode from disk and return a pointer to the
942  * incore copy. This routine will internally commit the current
943  * transaction and allocate a new one if the Space Manager needed
944  * to do an allocation to replenish the inode free-list.
945  *
946  * This routine is designed to be called from xfs_create and
947  * xfs_create_dir.
948  *
949  */
950 int
951 xfs_dir_ialloc(
952 	xfs_trans_t	**tpp,		/* input: current transaction;
953 					   output: may be a new transaction. */
954 	xfs_inode_t	*dp,		/* directory within whose allocate
955 					   the inode. */
956 	umode_t		mode,
957 	xfs_nlink_t	nlink,
958 	dev_t		rdev,
959 	prid_t		prid,		/* project id */
960 	int		okalloc,	/* ok to allocate new space */
961 	xfs_inode_t	**ipp,		/* pointer to inode; it will be
962 					   locked. */
963 	int		*committed)
964 
965 {
966 	xfs_trans_t	*tp;
967 	xfs_inode_t	*ip;
968 	xfs_buf_t	*ialloc_context = NULL;
969 	int		code;
970 	void		*dqinfo;
971 	uint		tflags;
972 
973 	tp = *tpp;
974 	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
975 
976 	/*
977 	 * xfs_ialloc will return a pointer to an incore inode if
978 	 * the Space Manager has an available inode on the free
979 	 * list. Otherwise, it will do an allocation and replenish
980 	 * the freelist.  Since we can only do one allocation per
981 	 * transaction without deadlocks, we will need to commit the
982 	 * current transaction and start a new one.  We will then
983 	 * need to call xfs_ialloc again to get the inode.
984 	 *
985 	 * If xfs_ialloc did an allocation to replenish the freelist,
986 	 * it returns the bp containing the head of the freelist as
987 	 * ialloc_context. We will hold a lock on it across the
988 	 * transaction commit so that no other process can steal
989 	 * the inode(s) that we've just allocated.
990 	 */
991 	code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, okalloc,
992 			  &ialloc_context, &ip);
993 
994 	/*
995 	 * Return an error if we were unable to allocate a new inode.
996 	 * This should only happen if we run out of space on disk or
997 	 * encounter a disk error.
998 	 */
999 	if (code) {
1000 		*ipp = NULL;
1001 		return code;
1002 	}
1003 	if (!ialloc_context && !ip) {
1004 		*ipp = NULL;
1005 		return -ENOSPC;
1006 	}
1007 
1008 	/*
1009 	 * If the AGI buffer is non-NULL, then we were unable to get an
1010 	 * inode in one operation.  We need to commit the current
1011 	 * transaction and call xfs_ialloc() again.  It is guaranteed
1012 	 * to succeed the second time.
1013 	 */
1014 	if (ialloc_context) {
1015 		/*
1016 		 * Normally, xfs_trans_commit releases all the locks.
1017 		 * We call bhold to hang on to the ialloc_context across
1018 		 * the commit.  Holding this buffer prevents any other
1019 		 * processes from doing any allocations in this
1020 		 * allocation group.
1021 		 */
1022 		xfs_trans_bhold(tp, ialloc_context);
1023 
1024 		/*
1025 		 * We want the quota changes to be associated with the next
1026 		 * transaction, NOT this one. So, detach the dqinfo from this
1027 		 * and attach it to the next transaction.
1028 		 */
1029 		dqinfo = NULL;
1030 		tflags = 0;
1031 		if (tp->t_dqinfo) {
1032 			dqinfo = (void *)tp->t_dqinfo;
1033 			tp->t_dqinfo = NULL;
1034 			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
1035 			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
1036 		}
1037 
1038 		code = xfs_trans_roll(&tp);
1039 		if (committed != NULL)
1040 			*committed = 1;
1041 
1042 		/*
1043 		 * Re-attach the quota info that we detached from prev trx.
1044 		 */
1045 		if (dqinfo) {
1046 			tp->t_dqinfo = dqinfo;
1047 			tp->t_flags |= tflags;
1048 		}
1049 
1050 		if (code) {
1051 			xfs_buf_relse(ialloc_context);
1052 			*tpp = tp;
1053 			*ipp = NULL;
1054 			return code;
1055 		}
1056 		xfs_trans_bjoin(tp, ialloc_context);
1057 
1058 		/*
1059 		 * Call ialloc again. Since we've locked out all
1060 		 * other allocations in this allocation group,
1061 		 * this call should always succeed.
1062 		 */
1063 		code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
1064 				  okalloc, &ialloc_context, &ip);
1065 
1066 		/*
1067 		 * If we get an error at this point, return to the caller
1068 		 * so that the current transaction can be aborted.
1069 		 */
1070 		if (code) {
1071 			*tpp = tp;
1072 			*ipp = NULL;
1073 			return code;
1074 		}
1075 		ASSERT(!ialloc_context && ip);
1076 
1077 	} else {
1078 		if (committed != NULL)
1079 			*committed = 0;
1080 	}
1081 
1082 	*ipp = ip;
1083 	*tpp = tp;
1084 
1085 	return 0;
1086 }
1087 
1088 /*
1089  * Decrement the link count on an inode & log the change.  If this causes the
1090  * link count to go to zero, move the inode to AGI unlinked list so that it can
1091  * be freed when the last active reference goes away via xfs_inactive().
1092  */
1093 static int			/* error */
1094 xfs_droplink(
1095 	xfs_trans_t *tp,
1096 	xfs_inode_t *ip)
1097 {
1098 	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1099 
1100 	drop_nlink(VFS_I(ip));
1101 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1102 
1103 	if (VFS_I(ip)->i_nlink)
1104 		return 0;
1105 
1106 	return xfs_iunlink(tp, ip);
1107 }
1108 
1109 /*
1110  * Increment the link count on an inode & log the change.
1111  */
1112 static int
1113 xfs_bumplink(
1114 	xfs_trans_t *tp,
1115 	xfs_inode_t *ip)
1116 {
1117 	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1118 
1119 	ASSERT(ip->i_d.di_version > 1);
1120 	inc_nlink(VFS_I(ip));
1121 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1122 	return 0;
1123 }
1124 
1125 int
1126 xfs_create(
1127 	xfs_inode_t		*dp,
1128 	struct xfs_name		*name,
1129 	umode_t			mode,
1130 	dev_t			rdev,
1131 	xfs_inode_t		**ipp)
1132 {
1133 	int			is_dir = S_ISDIR(mode);
1134 	struct xfs_mount	*mp = dp->i_mount;
1135 	struct xfs_inode	*ip = NULL;
1136 	struct xfs_trans	*tp = NULL;
1137 	int			error;
1138 	struct xfs_defer_ops	dfops;
1139 	xfs_fsblock_t		first_block;
1140 	bool                    unlock_dp_on_error = false;
1141 	prid_t			prid;
1142 	struct xfs_dquot	*udqp = NULL;
1143 	struct xfs_dquot	*gdqp = NULL;
1144 	struct xfs_dquot	*pdqp = NULL;
1145 	struct xfs_trans_res	*tres;
1146 	uint			resblks;
1147 
1148 	trace_xfs_create(dp, name);
1149 
1150 	if (XFS_FORCED_SHUTDOWN(mp))
1151 		return -EIO;
1152 
1153 	prid = xfs_get_initial_prid(dp);
1154 
1155 	/*
1156 	 * Make sure that we have allocated dquot(s) on disk.
1157 	 */
1158 	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1159 					xfs_kgid_to_gid(current_fsgid()), prid,
1160 					XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1161 					&udqp, &gdqp, &pdqp);
1162 	if (error)
1163 		return error;
1164 
1165 	if (is_dir) {
1166 		resblks = XFS_MKDIR_SPACE_RES(mp, name->len);
1167 		tres = &M_RES(mp)->tr_mkdir;
1168 	} else {
1169 		resblks = XFS_CREATE_SPACE_RES(mp, name->len);
1170 		tres = &M_RES(mp)->tr_create;
1171 	}
1172 
1173 	/*
1174 	 * Initially assume that the file does not exist and
1175 	 * reserve the resources for that case.  If that is not
1176 	 * the case we'll drop the one we have and get a more
1177 	 * appropriate transaction later.
1178 	 */
1179 	error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1180 	if (error == -ENOSPC) {
1181 		/* flush outstanding delalloc blocks and retry */
1182 		xfs_flush_inodes(mp);
1183 		error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1184 	}
1185 	if (error == -ENOSPC) {
1186 		/* No space at all so try a "no-allocation" reservation */
1187 		resblks = 0;
1188 		error = xfs_trans_alloc(mp, tres, 0, 0, 0, &tp);
1189 	}
1190 	if (error)
1191 		goto out_release_inode;
1192 
1193 	xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
1194 	unlock_dp_on_error = true;
1195 
1196 	xfs_defer_init(&dfops, &first_block);
1197 
1198 	/*
1199 	 * Reserve disk quota and the inode.
1200 	 */
1201 	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1202 						pdqp, resblks, 1, 0);
1203 	if (error)
1204 		goto out_trans_cancel;
1205 
1206 	if (!resblks) {
1207 		error = xfs_dir_canenter(tp, dp, name);
1208 		if (error)
1209 			goto out_trans_cancel;
1210 	}
1211 
1212 	/*
1213 	 * A newly created regular or special file just has one directory
1214 	 * entry pointing to them, but a directory also the "." entry
1215 	 * pointing to itself.
1216 	 */
1217 	error = xfs_dir_ialloc(&tp, dp, mode, is_dir ? 2 : 1, rdev,
1218 			       prid, resblks > 0, &ip, NULL);
1219 	if (error)
1220 		goto out_trans_cancel;
1221 
1222 	/*
1223 	 * Now we join the directory inode to the transaction.  We do not do it
1224 	 * earlier because xfs_dir_ialloc might commit the previous transaction
1225 	 * (and release all the locks).  An error from here on will result in
1226 	 * the transaction cancel unlocking dp so don't do it explicitly in the
1227 	 * error path.
1228 	 */
1229 	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
1230 	unlock_dp_on_error = false;
1231 
1232 	error = xfs_dir_createname(tp, dp, name, ip->i_ino,
1233 					&first_block, &dfops, resblks ?
1234 					resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
1235 	if (error) {
1236 		ASSERT(error != -ENOSPC);
1237 		goto out_trans_cancel;
1238 	}
1239 	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1240 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1241 
1242 	if (is_dir) {
1243 		error = xfs_dir_init(tp, ip, dp);
1244 		if (error)
1245 			goto out_bmap_cancel;
1246 
1247 		error = xfs_bumplink(tp, dp);
1248 		if (error)
1249 			goto out_bmap_cancel;
1250 	}
1251 
1252 	/*
1253 	 * If this is a synchronous mount, make sure that the
1254 	 * create transaction goes to disk before returning to
1255 	 * the user.
1256 	 */
1257 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1258 		xfs_trans_set_sync(tp);
1259 
1260 	/*
1261 	 * Attach the dquot(s) to the inodes and modify them incore.
1262 	 * These ids of the inode couldn't have changed since the new
1263 	 * inode has been locked ever since it was created.
1264 	 */
1265 	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1266 
1267 	error = xfs_defer_finish(&tp, &dfops);
1268 	if (error)
1269 		goto out_bmap_cancel;
1270 
1271 	error = xfs_trans_commit(tp);
1272 	if (error)
1273 		goto out_release_inode;
1274 
1275 	xfs_qm_dqrele(udqp);
1276 	xfs_qm_dqrele(gdqp);
1277 	xfs_qm_dqrele(pdqp);
1278 
1279 	*ipp = ip;
1280 	return 0;
1281 
1282  out_bmap_cancel:
1283 	xfs_defer_cancel(&dfops);
1284  out_trans_cancel:
1285 	xfs_trans_cancel(tp);
1286  out_release_inode:
1287 	/*
1288 	 * Wait until after the current transaction is aborted to finish the
1289 	 * setup of the inode and release the inode.  This prevents recursive
1290 	 * transactions and deadlocks from xfs_inactive.
1291 	 */
1292 	if (ip) {
1293 		xfs_finish_inode_setup(ip);
1294 		IRELE(ip);
1295 	}
1296 
1297 	xfs_qm_dqrele(udqp);
1298 	xfs_qm_dqrele(gdqp);
1299 	xfs_qm_dqrele(pdqp);
1300 
1301 	if (unlock_dp_on_error)
1302 		xfs_iunlock(dp, XFS_ILOCK_EXCL);
1303 	return error;
1304 }
1305 
1306 int
1307 xfs_create_tmpfile(
1308 	struct xfs_inode	*dp,
1309 	struct dentry		*dentry,
1310 	umode_t			mode,
1311 	struct xfs_inode	**ipp)
1312 {
1313 	struct xfs_mount	*mp = dp->i_mount;
1314 	struct xfs_inode	*ip = NULL;
1315 	struct xfs_trans	*tp = NULL;
1316 	int			error;
1317 	prid_t                  prid;
1318 	struct xfs_dquot	*udqp = NULL;
1319 	struct xfs_dquot	*gdqp = NULL;
1320 	struct xfs_dquot	*pdqp = NULL;
1321 	struct xfs_trans_res	*tres;
1322 	uint			resblks;
1323 
1324 	if (XFS_FORCED_SHUTDOWN(mp))
1325 		return -EIO;
1326 
1327 	prid = xfs_get_initial_prid(dp);
1328 
1329 	/*
1330 	 * Make sure that we have allocated dquot(s) on disk.
1331 	 */
1332 	error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1333 				xfs_kgid_to_gid(current_fsgid()), prid,
1334 				XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1335 				&udqp, &gdqp, &pdqp);
1336 	if (error)
1337 		return error;
1338 
1339 	resblks = XFS_IALLOC_SPACE_RES(mp);
1340 	tres = &M_RES(mp)->tr_create_tmpfile;
1341 
1342 	error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1343 	if (error == -ENOSPC) {
1344 		/* No space at all so try a "no-allocation" reservation */
1345 		resblks = 0;
1346 		error = xfs_trans_alloc(mp, tres, 0, 0, 0, &tp);
1347 	}
1348 	if (error)
1349 		goto out_release_inode;
1350 
1351 	error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1352 						pdqp, resblks, 1, 0);
1353 	if (error)
1354 		goto out_trans_cancel;
1355 
1356 	error = xfs_dir_ialloc(&tp, dp, mode, 1, 0,
1357 				prid, resblks > 0, &ip, NULL);
1358 	if (error)
1359 		goto out_trans_cancel;
1360 
1361 	if (mp->m_flags & XFS_MOUNT_WSYNC)
1362 		xfs_trans_set_sync(tp);
1363 
1364 	/*
1365 	 * Attach the dquot(s) to the inodes and modify them incore.
1366 	 * These ids of the inode couldn't have changed since the new
1367 	 * inode has been locked ever since it was created.
1368 	 */
1369 	xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1370 
1371 	error = xfs_iunlink(tp, ip);
1372 	if (error)
1373 		goto out_trans_cancel;
1374 
1375 	error = xfs_trans_commit(tp);
1376 	if (error)
1377 		goto out_release_inode;
1378 
1379 	xfs_qm_dqrele(udqp);
1380 	xfs_qm_dqrele(gdqp);
1381 	xfs_qm_dqrele(pdqp);
1382 
1383 	*ipp = ip;
1384 	return 0;
1385 
1386  out_trans_cancel:
1387 	xfs_trans_cancel(tp);
1388  out_release_inode:
1389 	/*
1390 	 * Wait until after the current transaction is aborted to finish the
1391 	 * setup of the inode and release the inode.  This prevents recursive
1392 	 * transactions and deadlocks from xfs_inactive.
1393 	 */
1394 	if (ip) {
1395 		xfs_finish_inode_setup(ip);
1396 		IRELE(ip);
1397 	}
1398 
1399 	xfs_qm_dqrele(udqp);
1400 	xfs_qm_dqrele(gdqp);
1401 	xfs_qm_dqrele(pdqp);
1402 
1403 	return error;
1404 }
1405 
1406 int
1407 xfs_link(
1408 	xfs_inode_t		*tdp,
1409 	xfs_inode_t		*sip,
1410 	struct xfs_name		*target_name)
1411 {
1412 	xfs_mount_t		*mp = tdp->i_mount;
1413 	xfs_trans_t		*tp;
1414 	int			error;
1415 	struct xfs_defer_ops	dfops;
1416 	xfs_fsblock_t           first_block;
1417 	int			resblks;
1418 
1419 	trace_xfs_link(tdp, target_name);
1420 
1421 	ASSERT(!S_ISDIR(VFS_I(sip)->i_mode));
1422 
1423 	if (XFS_FORCED_SHUTDOWN(mp))
1424 		return -EIO;
1425 
1426 	error = xfs_qm_dqattach(sip, 0);
1427 	if (error)
1428 		goto std_return;
1429 
1430 	error = xfs_qm_dqattach(tdp, 0);
1431 	if (error)
1432 		goto std_return;
1433 
1434 	resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
1435 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, resblks, 0, 0, &tp);
1436 	if (error == -ENOSPC) {
1437 		resblks = 0;
1438 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, 0, 0, 0, &tp);
1439 	}
1440 	if (error)
1441 		goto std_return;
1442 
1443 	xfs_lock_two_inodes(sip, tdp, XFS_ILOCK_EXCL);
1444 
1445 	xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
1446 	xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
1447 
1448 	/*
1449 	 * If we are using project inheritance, we only allow hard link
1450 	 * creation in our tree when the project IDs are the same; else
1451 	 * the tree quota mechanism could be circumvented.
1452 	 */
1453 	if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
1454 		     (xfs_get_projid(tdp) != xfs_get_projid(sip)))) {
1455 		error = -EXDEV;
1456 		goto error_return;
1457 	}
1458 
1459 	if (!resblks) {
1460 		error = xfs_dir_canenter(tp, tdp, target_name);
1461 		if (error)
1462 			goto error_return;
1463 	}
1464 
1465 	xfs_defer_init(&dfops, &first_block);
1466 
1467 	/*
1468 	 * Handle initial link state of O_TMPFILE inode
1469 	 */
1470 	if (VFS_I(sip)->i_nlink == 0) {
1471 		error = xfs_iunlink_remove(tp, sip);
1472 		if (error)
1473 			goto error_return;
1474 	}
1475 
1476 	error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
1477 					&first_block, &dfops, resblks);
1478 	if (error)
1479 		goto error_return;
1480 	xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1481 	xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
1482 
1483 	error = xfs_bumplink(tp, sip);
1484 	if (error)
1485 		goto error_return;
1486 
1487 	/*
1488 	 * If this is a synchronous mount, make sure that the
1489 	 * link transaction goes to disk before returning to
1490 	 * the user.
1491 	 */
1492 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1493 		xfs_trans_set_sync(tp);
1494 
1495 	error = xfs_defer_finish(&tp, &dfops);
1496 	if (error) {
1497 		xfs_defer_cancel(&dfops);
1498 		goto error_return;
1499 	}
1500 
1501 	return xfs_trans_commit(tp);
1502 
1503  error_return:
1504 	xfs_trans_cancel(tp);
1505  std_return:
1506 	return error;
1507 }
1508 
1509 /*
1510  * Free up the underlying blocks past new_size.  The new size must be smaller
1511  * than the current size.  This routine can be used both for the attribute and
1512  * data fork, and does not modify the inode size, which is left to the caller.
1513  *
1514  * The transaction passed to this routine must have made a permanent log
1515  * reservation of at least XFS_ITRUNCATE_LOG_RES.  This routine may commit the
1516  * given transaction and start new ones, so make sure everything involved in
1517  * the transaction is tidy before calling here.  Some transaction will be
1518  * returned to the caller to be committed.  The incoming transaction must
1519  * already include the inode, and both inode locks must be held exclusively.
1520  * The inode must also be "held" within the transaction.  On return the inode
1521  * will be "held" within the returned transaction.  This routine does NOT
1522  * require any disk space to be reserved for it within the transaction.
1523  *
1524  * If we get an error, we must return with the inode locked and linked into the
1525  * current transaction. This keeps things simple for the higher level code,
1526  * because it always knows that the inode is locked and held in the transaction
1527  * that returns to it whether errors occur or not.  We don't mark the inode
1528  * dirty on error so that transactions can be easily aborted if possible.
1529  */
1530 int
1531 xfs_itruncate_extents(
1532 	struct xfs_trans	**tpp,
1533 	struct xfs_inode	*ip,
1534 	int			whichfork,
1535 	xfs_fsize_t		new_size)
1536 {
1537 	struct xfs_mount	*mp = ip->i_mount;
1538 	struct xfs_trans	*tp = *tpp;
1539 	struct xfs_defer_ops	dfops;
1540 	xfs_fsblock_t		first_block;
1541 	xfs_fileoff_t		first_unmap_block;
1542 	xfs_fileoff_t		last_block;
1543 	xfs_filblks_t		unmap_len;
1544 	int			error = 0;
1545 	int			done = 0;
1546 
1547 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1548 	ASSERT(!atomic_read(&VFS_I(ip)->i_count) ||
1549 	       xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1550 	ASSERT(new_size <= XFS_ISIZE(ip));
1551 	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
1552 	ASSERT(ip->i_itemp != NULL);
1553 	ASSERT(ip->i_itemp->ili_lock_flags == 0);
1554 	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1555 
1556 	trace_xfs_itruncate_extents_start(ip, new_size);
1557 
1558 	/*
1559 	 * Since it is possible for space to become allocated beyond
1560 	 * the end of the file (in a crash where the space is allocated
1561 	 * but the inode size is not yet updated), simply remove any
1562 	 * blocks which show up between the new EOF and the maximum
1563 	 * possible file size.  If the first block to be removed is
1564 	 * beyond the maximum file size (ie it is the same as last_block),
1565 	 * then there is nothing to do.
1566 	 */
1567 	first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
1568 	last_block = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
1569 	if (first_unmap_block == last_block)
1570 		return 0;
1571 
1572 	ASSERT(first_unmap_block < last_block);
1573 	unmap_len = last_block - first_unmap_block + 1;
1574 	while (!done) {
1575 		xfs_defer_init(&dfops, &first_block);
1576 		error = xfs_bunmapi(tp, ip,
1577 				    first_unmap_block, unmap_len,
1578 				    xfs_bmapi_aflag(whichfork),
1579 				    XFS_ITRUNC_MAX_EXTENTS,
1580 				    &first_block, &dfops,
1581 				    &done);
1582 		if (error)
1583 			goto out_bmap_cancel;
1584 
1585 		/*
1586 		 * Duplicate the transaction that has the permanent
1587 		 * reservation and commit the old transaction.
1588 		 */
1589 		xfs_defer_ijoin(&dfops, ip);
1590 		error = xfs_defer_finish(&tp, &dfops);
1591 		if (error)
1592 			goto out_bmap_cancel;
1593 
1594 		error = xfs_trans_roll_inode(&tp, ip);
1595 		if (error)
1596 			goto out;
1597 	}
1598 
1599 	/* Remove all pending CoW reservations. */
1600 	error = xfs_reflink_cancel_cow_blocks(ip, &tp, first_unmap_block,
1601 			last_block, true);
1602 	if (error)
1603 		goto out;
1604 
1605 	/*
1606 	 * Clear the reflink flag if there are no data fork blocks and
1607 	 * there are no extents staged in the cow fork.
1608 	 */
1609 	if (xfs_is_reflink_inode(ip) && ip->i_cnextents == 0) {
1610 		if (ip->i_d.di_nblocks == 0)
1611 			ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
1612 		xfs_inode_clear_cowblocks_tag(ip);
1613 	}
1614 
1615 	/*
1616 	 * Always re-log the inode so that our permanent transaction can keep
1617 	 * on rolling it forward in the log.
1618 	 */
1619 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1620 
1621 	trace_xfs_itruncate_extents_end(ip, new_size);
1622 
1623 out:
1624 	*tpp = tp;
1625 	return error;
1626 out_bmap_cancel:
1627 	/*
1628 	 * If the bunmapi call encounters an error, return to the caller where
1629 	 * the transaction can be properly aborted.  We just need to make sure
1630 	 * we're not holding any resources that we were not when we came in.
1631 	 */
1632 	xfs_defer_cancel(&dfops);
1633 	goto out;
1634 }
1635 
1636 int
1637 xfs_release(
1638 	xfs_inode_t	*ip)
1639 {
1640 	xfs_mount_t	*mp = ip->i_mount;
1641 	int		error;
1642 
1643 	if (!S_ISREG(VFS_I(ip)->i_mode) || (VFS_I(ip)->i_mode == 0))
1644 		return 0;
1645 
1646 	/* If this is a read-only mount, don't do this (would generate I/O) */
1647 	if (mp->m_flags & XFS_MOUNT_RDONLY)
1648 		return 0;
1649 
1650 	if (!XFS_FORCED_SHUTDOWN(mp)) {
1651 		int truncated;
1652 
1653 		/*
1654 		 * If we previously truncated this file and removed old data
1655 		 * in the process, we want to initiate "early" writeout on
1656 		 * the last close.  This is an attempt to combat the notorious
1657 		 * NULL files problem which is particularly noticeable from a
1658 		 * truncate down, buffered (re-)write (delalloc), followed by
1659 		 * a crash.  What we are effectively doing here is
1660 		 * significantly reducing the time window where we'd otherwise
1661 		 * be exposed to that problem.
1662 		 */
1663 		truncated = xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED);
1664 		if (truncated) {
1665 			xfs_iflags_clear(ip, XFS_IDIRTY_RELEASE);
1666 			if (ip->i_delayed_blks > 0) {
1667 				error = filemap_flush(VFS_I(ip)->i_mapping);
1668 				if (error)
1669 					return error;
1670 			}
1671 		}
1672 	}
1673 
1674 	if (VFS_I(ip)->i_nlink == 0)
1675 		return 0;
1676 
1677 	if (xfs_can_free_eofblocks(ip, false)) {
1678 
1679 		/*
1680 		 * Check if the inode is being opened, written and closed
1681 		 * frequently and we have delayed allocation blocks outstanding
1682 		 * (e.g. streaming writes from the NFS server), truncating the
1683 		 * blocks past EOF will cause fragmentation to occur.
1684 		 *
1685 		 * In this case don't do the truncation, but we have to be
1686 		 * careful how we detect this case. Blocks beyond EOF show up as
1687 		 * i_delayed_blks even when the inode is clean, so we need to
1688 		 * truncate them away first before checking for a dirty release.
1689 		 * Hence on the first dirty close we will still remove the
1690 		 * speculative allocation, but after that we will leave it in
1691 		 * place.
1692 		 */
1693 		if (xfs_iflags_test(ip, XFS_IDIRTY_RELEASE))
1694 			return 0;
1695 		/*
1696 		 * If we can't get the iolock just skip truncating the blocks
1697 		 * past EOF because we could deadlock with the mmap_sem
1698 		 * otherwise. We'll get another chance to drop them once the
1699 		 * last reference to the inode is dropped, so we'll never leak
1700 		 * blocks permanently.
1701 		 */
1702 		if (xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1703 			error = xfs_free_eofblocks(ip);
1704 			xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1705 			if (error)
1706 				return error;
1707 		}
1708 
1709 		/* delalloc blocks after truncation means it really is dirty */
1710 		if (ip->i_delayed_blks)
1711 			xfs_iflags_set(ip, XFS_IDIRTY_RELEASE);
1712 	}
1713 	return 0;
1714 }
1715 
1716 /*
1717  * xfs_inactive_truncate
1718  *
1719  * Called to perform a truncate when an inode becomes unlinked.
1720  */
1721 STATIC int
1722 xfs_inactive_truncate(
1723 	struct xfs_inode *ip)
1724 {
1725 	struct xfs_mount	*mp = ip->i_mount;
1726 	struct xfs_trans	*tp;
1727 	int			error;
1728 
1729 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
1730 	if (error) {
1731 		ASSERT(XFS_FORCED_SHUTDOWN(mp));
1732 		return error;
1733 	}
1734 
1735 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1736 	xfs_trans_ijoin(tp, ip, 0);
1737 
1738 	/*
1739 	 * Log the inode size first to prevent stale data exposure in the event
1740 	 * of a system crash before the truncate completes. See the related
1741 	 * comment in xfs_vn_setattr_size() for details.
1742 	 */
1743 	ip->i_d.di_size = 0;
1744 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1745 
1746 	error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
1747 	if (error)
1748 		goto error_trans_cancel;
1749 
1750 	ASSERT(ip->i_d.di_nextents == 0);
1751 
1752 	error = xfs_trans_commit(tp);
1753 	if (error)
1754 		goto error_unlock;
1755 
1756 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1757 	return 0;
1758 
1759 error_trans_cancel:
1760 	xfs_trans_cancel(tp);
1761 error_unlock:
1762 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1763 	return error;
1764 }
1765 
1766 /*
1767  * xfs_inactive_ifree()
1768  *
1769  * Perform the inode free when an inode is unlinked.
1770  */
1771 STATIC int
1772 xfs_inactive_ifree(
1773 	struct xfs_inode *ip)
1774 {
1775 	struct xfs_defer_ops	dfops;
1776 	xfs_fsblock_t		first_block;
1777 	struct xfs_mount	*mp = ip->i_mount;
1778 	struct xfs_trans	*tp;
1779 	int			error;
1780 
1781 	/*
1782 	 * We try to use a per-AG reservation for any block needed by the finobt
1783 	 * tree, but as the finobt feature predates the per-AG reservation
1784 	 * support a degraded file system might not have enough space for the
1785 	 * reservation at mount time.  In that case try to dip into the reserved
1786 	 * pool and pray.
1787 	 *
1788 	 * Send a warning if the reservation does happen to fail, as the inode
1789 	 * now remains allocated and sits on the unlinked list until the fs is
1790 	 * repaired.
1791 	 */
1792 	if (unlikely(mp->m_inotbt_nores)) {
1793 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree,
1794 				XFS_IFREE_SPACE_RES(mp), 0, XFS_TRANS_RESERVE,
1795 				&tp);
1796 	} else {
1797 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree, 0, 0, 0, &tp);
1798 	}
1799 	if (error) {
1800 		if (error == -ENOSPC) {
1801 			xfs_warn_ratelimited(mp,
1802 			"Failed to remove inode(s) from unlinked list. "
1803 			"Please free space, unmount and run xfs_repair.");
1804 		} else {
1805 			ASSERT(XFS_FORCED_SHUTDOWN(mp));
1806 		}
1807 		return error;
1808 	}
1809 
1810 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1811 	xfs_trans_ijoin(tp, ip, 0);
1812 
1813 	xfs_defer_init(&dfops, &first_block);
1814 	error = xfs_ifree(tp, ip, &dfops);
1815 	if (error) {
1816 		/*
1817 		 * If we fail to free the inode, shut down.  The cancel
1818 		 * might do that, we need to make sure.  Otherwise the
1819 		 * inode might be lost for a long time or forever.
1820 		 */
1821 		if (!XFS_FORCED_SHUTDOWN(mp)) {
1822 			xfs_notice(mp, "%s: xfs_ifree returned error %d",
1823 				__func__, error);
1824 			xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
1825 		}
1826 		xfs_trans_cancel(tp);
1827 		xfs_iunlock(ip, XFS_ILOCK_EXCL);
1828 		return error;
1829 	}
1830 
1831 	/*
1832 	 * Credit the quota account(s). The inode is gone.
1833 	 */
1834 	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_ICOUNT, -1);
1835 
1836 	/*
1837 	 * Just ignore errors at this point.  There is nothing we can do except
1838 	 * to try to keep going. Make sure it's not a silent error.
1839 	 */
1840 	error = xfs_defer_finish(&tp, &dfops);
1841 	if (error) {
1842 		xfs_notice(mp, "%s: xfs_defer_finish returned error %d",
1843 			__func__, error);
1844 		xfs_defer_cancel(&dfops);
1845 	}
1846 	error = xfs_trans_commit(tp);
1847 	if (error)
1848 		xfs_notice(mp, "%s: xfs_trans_commit returned error %d",
1849 			__func__, error);
1850 
1851 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1852 	return 0;
1853 }
1854 
1855 /*
1856  * xfs_inactive
1857  *
1858  * This is called when the vnode reference count for the vnode
1859  * goes to zero.  If the file has been unlinked, then it must
1860  * now be truncated.  Also, we clear all of the read-ahead state
1861  * kept for the inode here since the file is now closed.
1862  */
1863 void
1864 xfs_inactive(
1865 	xfs_inode_t	*ip)
1866 {
1867 	struct xfs_mount	*mp;
1868 	int			error;
1869 	int			truncate = 0;
1870 
1871 	/*
1872 	 * If the inode is already free, then there can be nothing
1873 	 * to clean up here.
1874 	 */
1875 	if (VFS_I(ip)->i_mode == 0) {
1876 		ASSERT(ip->i_df.if_real_bytes == 0);
1877 		ASSERT(ip->i_df.if_broot_bytes == 0);
1878 		return;
1879 	}
1880 
1881 	mp = ip->i_mount;
1882 	ASSERT(!xfs_iflags_test(ip, XFS_IRECOVERY));
1883 
1884 	/* If this is a read-only mount, don't do this (would generate I/O) */
1885 	if (mp->m_flags & XFS_MOUNT_RDONLY)
1886 		return;
1887 
1888 	if (VFS_I(ip)->i_nlink != 0) {
1889 		/*
1890 		 * force is true because we are evicting an inode from the
1891 		 * cache. Post-eof blocks must be freed, lest we end up with
1892 		 * broken free space accounting.
1893 		 *
1894 		 * Note: don't bother with iolock here since lockdep complains
1895 		 * about acquiring it in reclaim context. We have the only
1896 		 * reference to the inode at this point anyways.
1897 		 */
1898 		if (xfs_can_free_eofblocks(ip, true))
1899 			xfs_free_eofblocks(ip);
1900 
1901 		return;
1902 	}
1903 
1904 	if (S_ISREG(VFS_I(ip)->i_mode) &&
1905 	    (ip->i_d.di_size != 0 || XFS_ISIZE(ip) != 0 ||
1906 	     ip->i_d.di_nextents > 0 || ip->i_delayed_blks > 0))
1907 		truncate = 1;
1908 
1909 	error = xfs_qm_dqattach(ip, 0);
1910 	if (error)
1911 		return;
1912 
1913 	if (S_ISLNK(VFS_I(ip)->i_mode))
1914 		error = xfs_inactive_symlink(ip);
1915 	else if (truncate)
1916 		error = xfs_inactive_truncate(ip);
1917 	if (error)
1918 		return;
1919 
1920 	/*
1921 	 * If there are attributes associated with the file then blow them away
1922 	 * now.  The code calls a routine that recursively deconstructs the
1923 	 * attribute fork. If also blows away the in-core attribute fork.
1924 	 */
1925 	if (XFS_IFORK_Q(ip)) {
1926 		error = xfs_attr_inactive(ip);
1927 		if (error)
1928 			return;
1929 	}
1930 
1931 	ASSERT(!ip->i_afp);
1932 	ASSERT(ip->i_d.di_anextents == 0);
1933 	ASSERT(ip->i_d.di_forkoff == 0);
1934 
1935 	/*
1936 	 * Free the inode.
1937 	 */
1938 	error = xfs_inactive_ifree(ip);
1939 	if (error)
1940 		return;
1941 
1942 	/*
1943 	 * Release the dquots held by inode, if any.
1944 	 */
1945 	xfs_qm_dqdetach(ip);
1946 }
1947 
1948 /*
1949  * This is called when the inode's link count goes to 0 or we are creating a
1950  * tmpfile via O_TMPFILE. In the case of a tmpfile, @ignore_linkcount will be
1951  * set to true as the link count is dropped to zero by the VFS after we've
1952  * created the file successfully, so we have to add it to the unlinked list
1953  * while the link count is non-zero.
1954  *
1955  * We place the on-disk inode on a list in the AGI.  It will be pulled from this
1956  * list when the inode is freed.
1957  */
1958 STATIC int
1959 xfs_iunlink(
1960 	struct xfs_trans *tp,
1961 	struct xfs_inode *ip)
1962 {
1963 	xfs_mount_t	*mp = tp->t_mountp;
1964 	xfs_agi_t	*agi;
1965 	xfs_dinode_t	*dip;
1966 	xfs_buf_t	*agibp;
1967 	xfs_buf_t	*ibp;
1968 	xfs_agino_t	agino;
1969 	short		bucket_index;
1970 	int		offset;
1971 	int		error;
1972 
1973 	ASSERT(VFS_I(ip)->i_mode != 0);
1974 
1975 	/*
1976 	 * Get the agi buffer first.  It ensures lock ordering
1977 	 * on the list.
1978 	 */
1979 	error = xfs_read_agi(mp, tp, XFS_INO_TO_AGNO(mp, ip->i_ino), &agibp);
1980 	if (error)
1981 		return error;
1982 	agi = XFS_BUF_TO_AGI(agibp);
1983 
1984 	/*
1985 	 * Get the index into the agi hash table for the
1986 	 * list this inode will go on.
1987 	 */
1988 	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
1989 	ASSERT(agino != 0);
1990 	bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
1991 	ASSERT(agi->agi_unlinked[bucket_index]);
1992 	ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino);
1993 
1994 	if (agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO)) {
1995 		/*
1996 		 * There is already another inode in the bucket we need
1997 		 * to add ourselves to.  Add us at the front of the list.
1998 		 * Here we put the head pointer into our next pointer,
1999 		 * and then we fall through to point the head at us.
2000 		 */
2001 		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2002 				       0, 0);
2003 		if (error)
2004 			return error;
2005 
2006 		ASSERT(dip->di_next_unlinked == cpu_to_be32(NULLAGINO));
2007 		dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
2008 		offset = ip->i_imap.im_boffset +
2009 			offsetof(xfs_dinode_t, di_next_unlinked);
2010 
2011 		/* need to recalc the inode CRC if appropriate */
2012 		xfs_dinode_calc_crc(mp, dip);
2013 
2014 		xfs_trans_inode_buf(tp, ibp);
2015 		xfs_trans_log_buf(tp, ibp, offset,
2016 				  (offset + sizeof(xfs_agino_t) - 1));
2017 		xfs_inobp_check(mp, ibp);
2018 	}
2019 
2020 	/*
2021 	 * Point the bucket head pointer at the inode being inserted.
2022 	 */
2023 	ASSERT(agino != 0);
2024 	agi->agi_unlinked[bucket_index] = cpu_to_be32(agino);
2025 	offset = offsetof(xfs_agi_t, agi_unlinked) +
2026 		(sizeof(xfs_agino_t) * bucket_index);
2027 	xfs_trans_log_buf(tp, agibp, offset,
2028 			  (offset + sizeof(xfs_agino_t) - 1));
2029 	return 0;
2030 }
2031 
2032 /*
2033  * Pull the on-disk inode from the AGI unlinked list.
2034  */
2035 STATIC int
2036 xfs_iunlink_remove(
2037 	xfs_trans_t	*tp,
2038 	xfs_inode_t	*ip)
2039 {
2040 	xfs_ino_t	next_ino;
2041 	xfs_mount_t	*mp;
2042 	xfs_agi_t	*agi;
2043 	xfs_dinode_t	*dip;
2044 	xfs_buf_t	*agibp;
2045 	xfs_buf_t	*ibp;
2046 	xfs_agnumber_t	agno;
2047 	xfs_agino_t	agino;
2048 	xfs_agino_t	next_agino;
2049 	xfs_buf_t	*last_ibp;
2050 	xfs_dinode_t	*last_dip = NULL;
2051 	short		bucket_index;
2052 	int		offset, last_offset = 0;
2053 	int		error;
2054 
2055 	mp = tp->t_mountp;
2056 	agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
2057 
2058 	/*
2059 	 * Get the agi buffer first.  It ensures lock ordering
2060 	 * on the list.
2061 	 */
2062 	error = xfs_read_agi(mp, tp, agno, &agibp);
2063 	if (error)
2064 		return error;
2065 
2066 	agi = XFS_BUF_TO_AGI(agibp);
2067 
2068 	/*
2069 	 * Get the index into the agi hash table for the
2070 	 * list this inode will go on.
2071 	 */
2072 	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
2073 	ASSERT(agino != 0);
2074 	bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
2075 	ASSERT(agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO));
2076 	ASSERT(agi->agi_unlinked[bucket_index]);
2077 
2078 	if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
2079 		/*
2080 		 * We're at the head of the list.  Get the inode's on-disk
2081 		 * buffer to see if there is anyone after us on the list.
2082 		 * Only modify our next pointer if it is not already NULLAGINO.
2083 		 * This saves us the overhead of dealing with the buffer when
2084 		 * there is no need to change it.
2085 		 */
2086 		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2087 				       0, 0);
2088 		if (error) {
2089 			xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
2090 				__func__, error);
2091 			return error;
2092 		}
2093 		next_agino = be32_to_cpu(dip->di_next_unlinked);
2094 		ASSERT(next_agino != 0);
2095 		if (next_agino != NULLAGINO) {
2096 			dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2097 			offset = ip->i_imap.im_boffset +
2098 				offsetof(xfs_dinode_t, di_next_unlinked);
2099 
2100 			/* need to recalc the inode CRC if appropriate */
2101 			xfs_dinode_calc_crc(mp, dip);
2102 
2103 			xfs_trans_inode_buf(tp, ibp);
2104 			xfs_trans_log_buf(tp, ibp, offset,
2105 					  (offset + sizeof(xfs_agino_t) - 1));
2106 			xfs_inobp_check(mp, ibp);
2107 		} else {
2108 			xfs_trans_brelse(tp, ibp);
2109 		}
2110 		/*
2111 		 * Point the bucket head pointer at the next inode.
2112 		 */
2113 		ASSERT(next_agino != 0);
2114 		ASSERT(next_agino != agino);
2115 		agi->agi_unlinked[bucket_index] = cpu_to_be32(next_agino);
2116 		offset = offsetof(xfs_agi_t, agi_unlinked) +
2117 			(sizeof(xfs_agino_t) * bucket_index);
2118 		xfs_trans_log_buf(tp, agibp, offset,
2119 				  (offset + sizeof(xfs_agino_t) - 1));
2120 	} else {
2121 		/*
2122 		 * We need to search the list for the inode being freed.
2123 		 */
2124 		next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
2125 		last_ibp = NULL;
2126 		while (next_agino != agino) {
2127 			struct xfs_imap	imap;
2128 
2129 			if (last_ibp)
2130 				xfs_trans_brelse(tp, last_ibp);
2131 
2132 			imap.im_blkno = 0;
2133 			next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
2134 
2135 			error = xfs_imap(mp, tp, next_ino, &imap, 0);
2136 			if (error) {
2137 				xfs_warn(mp,
2138 	"%s: xfs_imap returned error %d.",
2139 					 __func__, error);
2140 				return error;
2141 			}
2142 
2143 			error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,
2144 					       &last_ibp, 0, 0);
2145 			if (error) {
2146 				xfs_warn(mp,
2147 	"%s: xfs_imap_to_bp returned error %d.",
2148 					__func__, error);
2149 				return error;
2150 			}
2151 
2152 			last_offset = imap.im_boffset;
2153 			next_agino = be32_to_cpu(last_dip->di_next_unlinked);
2154 			ASSERT(next_agino != NULLAGINO);
2155 			ASSERT(next_agino != 0);
2156 		}
2157 
2158 		/*
2159 		 * Now last_ibp points to the buffer previous to us on the
2160 		 * unlinked list.  Pull us from the list.
2161 		 */
2162 		error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2163 				       0, 0);
2164 		if (error) {
2165 			xfs_warn(mp, "%s: xfs_imap_to_bp(2) returned error %d.",
2166 				__func__, error);
2167 			return error;
2168 		}
2169 		next_agino = be32_to_cpu(dip->di_next_unlinked);
2170 		ASSERT(next_agino != 0);
2171 		ASSERT(next_agino != agino);
2172 		if (next_agino != NULLAGINO) {
2173 			dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2174 			offset = ip->i_imap.im_boffset +
2175 				offsetof(xfs_dinode_t, di_next_unlinked);
2176 
2177 			/* need to recalc the inode CRC if appropriate */
2178 			xfs_dinode_calc_crc(mp, dip);
2179 
2180 			xfs_trans_inode_buf(tp, ibp);
2181 			xfs_trans_log_buf(tp, ibp, offset,
2182 					  (offset + sizeof(xfs_agino_t) - 1));
2183 			xfs_inobp_check(mp, ibp);
2184 		} else {
2185 			xfs_trans_brelse(tp, ibp);
2186 		}
2187 		/*
2188 		 * Point the previous inode on the list to the next inode.
2189 		 */
2190 		last_dip->di_next_unlinked = cpu_to_be32(next_agino);
2191 		ASSERT(next_agino != 0);
2192 		offset = last_offset + offsetof(xfs_dinode_t, di_next_unlinked);
2193 
2194 		/* need to recalc the inode CRC if appropriate */
2195 		xfs_dinode_calc_crc(mp, last_dip);
2196 
2197 		xfs_trans_inode_buf(tp, last_ibp);
2198 		xfs_trans_log_buf(tp, last_ibp, offset,
2199 				  (offset + sizeof(xfs_agino_t) - 1));
2200 		xfs_inobp_check(mp, last_ibp);
2201 	}
2202 	return 0;
2203 }
2204 
2205 /*
2206  * A big issue when freeing the inode cluster is that we _cannot_ skip any
2207  * inodes that are in memory - they all must be marked stale and attached to
2208  * the cluster buffer.
2209  */
2210 STATIC int
2211 xfs_ifree_cluster(
2212 	xfs_inode_t		*free_ip,
2213 	xfs_trans_t		*tp,
2214 	struct xfs_icluster	*xic)
2215 {
2216 	xfs_mount_t		*mp = free_ip->i_mount;
2217 	int			blks_per_cluster;
2218 	int			inodes_per_cluster;
2219 	int			nbufs;
2220 	int			i, j;
2221 	int			ioffset;
2222 	xfs_daddr_t		blkno;
2223 	xfs_buf_t		*bp;
2224 	xfs_inode_t		*ip;
2225 	xfs_inode_log_item_t	*iip;
2226 	xfs_log_item_t		*lip;
2227 	struct xfs_perag	*pag;
2228 	xfs_ino_t		inum;
2229 
2230 	inum = xic->first_ino;
2231 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, inum));
2232 	blks_per_cluster = xfs_icluster_size_fsb(mp);
2233 	inodes_per_cluster = blks_per_cluster << mp->m_sb.sb_inopblog;
2234 	nbufs = mp->m_ialloc_blks / blks_per_cluster;
2235 
2236 	for (j = 0; j < nbufs; j++, inum += inodes_per_cluster) {
2237 		/*
2238 		 * The allocation bitmap tells us which inodes of the chunk were
2239 		 * physically allocated. Skip the cluster if an inode falls into
2240 		 * a sparse region.
2241 		 */
2242 		ioffset = inum - xic->first_ino;
2243 		if ((xic->alloc & XFS_INOBT_MASK(ioffset)) == 0) {
2244 			ASSERT(do_mod(ioffset, inodes_per_cluster) == 0);
2245 			continue;
2246 		}
2247 
2248 		blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
2249 					 XFS_INO_TO_AGBNO(mp, inum));
2250 
2251 		/*
2252 		 * We obtain and lock the backing buffer first in the process
2253 		 * here, as we have to ensure that any dirty inode that we
2254 		 * can't get the flush lock on is attached to the buffer.
2255 		 * If we scan the in-memory inodes first, then buffer IO can
2256 		 * complete before we get a lock on it, and hence we may fail
2257 		 * to mark all the active inodes on the buffer stale.
2258 		 */
2259 		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
2260 					mp->m_bsize * blks_per_cluster,
2261 					XBF_UNMAPPED);
2262 
2263 		if (!bp)
2264 			return -ENOMEM;
2265 
2266 		/*
2267 		 * This buffer may not have been correctly initialised as we
2268 		 * didn't read it from disk. That's not important because we are
2269 		 * only using to mark the buffer as stale in the log, and to
2270 		 * attach stale cached inodes on it. That means it will never be
2271 		 * dispatched for IO. If it is, we want to know about it, and we
2272 		 * want it to fail. We can acheive this by adding a write
2273 		 * verifier to the buffer.
2274 		 */
2275 		 bp->b_ops = &xfs_inode_buf_ops;
2276 
2277 		/*
2278 		 * Walk the inodes already attached to the buffer and mark them
2279 		 * stale. These will all have the flush locks held, so an
2280 		 * in-memory inode walk can't lock them. By marking them all
2281 		 * stale first, we will not attempt to lock them in the loop
2282 		 * below as the XFS_ISTALE flag will be set.
2283 		 */
2284 		lip = bp->b_fspriv;
2285 		while (lip) {
2286 			if (lip->li_type == XFS_LI_INODE) {
2287 				iip = (xfs_inode_log_item_t *)lip;
2288 				ASSERT(iip->ili_logged == 1);
2289 				lip->li_cb = xfs_istale_done;
2290 				xfs_trans_ail_copy_lsn(mp->m_ail,
2291 							&iip->ili_flush_lsn,
2292 							&iip->ili_item.li_lsn);
2293 				xfs_iflags_set(iip->ili_inode, XFS_ISTALE);
2294 			}
2295 			lip = lip->li_bio_list;
2296 		}
2297 
2298 
2299 		/*
2300 		 * For each inode in memory attempt to add it to the inode
2301 		 * buffer and set it up for being staled on buffer IO
2302 		 * completion.  This is safe as we've locked out tail pushing
2303 		 * and flushing by locking the buffer.
2304 		 *
2305 		 * We have already marked every inode that was part of a
2306 		 * transaction stale above, which means there is no point in
2307 		 * even trying to lock them.
2308 		 */
2309 		for (i = 0; i < inodes_per_cluster; i++) {
2310 retry:
2311 			rcu_read_lock();
2312 			ip = radix_tree_lookup(&pag->pag_ici_root,
2313 					XFS_INO_TO_AGINO(mp, (inum + i)));
2314 
2315 			/* Inode not in memory, nothing to do */
2316 			if (!ip) {
2317 				rcu_read_unlock();
2318 				continue;
2319 			}
2320 
2321 			/*
2322 			 * because this is an RCU protected lookup, we could
2323 			 * find a recently freed or even reallocated inode
2324 			 * during the lookup. We need to check under the
2325 			 * i_flags_lock for a valid inode here. Skip it if it
2326 			 * is not valid, the wrong inode or stale.
2327 			 */
2328 			spin_lock(&ip->i_flags_lock);
2329 			if (ip->i_ino != inum + i ||
2330 			    __xfs_iflags_test(ip, XFS_ISTALE)) {
2331 				spin_unlock(&ip->i_flags_lock);
2332 				rcu_read_unlock();
2333 				continue;
2334 			}
2335 			spin_unlock(&ip->i_flags_lock);
2336 
2337 			/*
2338 			 * Don't try to lock/unlock the current inode, but we
2339 			 * _cannot_ skip the other inodes that we did not find
2340 			 * in the list attached to the buffer and are not
2341 			 * already marked stale. If we can't lock it, back off
2342 			 * and retry.
2343 			 */
2344 			if (ip != free_ip) {
2345 				if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
2346 					rcu_read_unlock();
2347 					delay(1);
2348 					goto retry;
2349 				}
2350 
2351 				/*
2352 				 * Check the inode number again in case we're
2353 				 * racing with freeing in xfs_reclaim_inode().
2354 				 * See the comments in that function for more
2355 				 * information as to why the initial check is
2356 				 * not sufficient.
2357 				 */
2358 				if (ip->i_ino != inum + i) {
2359 					xfs_iunlock(ip, XFS_ILOCK_EXCL);
2360 					rcu_read_unlock();
2361 					continue;
2362 				}
2363 			}
2364 			rcu_read_unlock();
2365 
2366 			xfs_iflock(ip);
2367 			xfs_iflags_set(ip, XFS_ISTALE);
2368 
2369 			/*
2370 			 * we don't need to attach clean inodes or those only
2371 			 * with unlogged changes (which we throw away, anyway).
2372 			 */
2373 			iip = ip->i_itemp;
2374 			if (!iip || xfs_inode_clean(ip)) {
2375 				ASSERT(ip != free_ip);
2376 				xfs_ifunlock(ip);
2377 				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2378 				continue;
2379 			}
2380 
2381 			iip->ili_last_fields = iip->ili_fields;
2382 			iip->ili_fields = 0;
2383 			iip->ili_fsync_fields = 0;
2384 			iip->ili_logged = 1;
2385 			xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
2386 						&iip->ili_item.li_lsn);
2387 
2388 			xfs_buf_attach_iodone(bp, xfs_istale_done,
2389 						  &iip->ili_item);
2390 
2391 			if (ip != free_ip)
2392 				xfs_iunlock(ip, XFS_ILOCK_EXCL);
2393 		}
2394 
2395 		xfs_trans_stale_inode_buf(tp, bp);
2396 		xfs_trans_binval(tp, bp);
2397 	}
2398 
2399 	xfs_perag_put(pag);
2400 	return 0;
2401 }
2402 
2403 /*
2404  * This is called to return an inode to the inode free list.
2405  * The inode should already be truncated to 0 length and have
2406  * no pages associated with it.  This routine also assumes that
2407  * the inode is already a part of the transaction.
2408  *
2409  * The on-disk copy of the inode will have been added to the list
2410  * of unlinked inodes in the AGI. We need to remove the inode from
2411  * that list atomically with respect to freeing it here.
2412  */
2413 int
2414 xfs_ifree(
2415 	xfs_trans_t	*tp,
2416 	xfs_inode_t	*ip,
2417 	struct xfs_defer_ops	*dfops)
2418 {
2419 	int			error;
2420 	struct xfs_icluster	xic = { 0 };
2421 
2422 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
2423 	ASSERT(VFS_I(ip)->i_nlink == 0);
2424 	ASSERT(ip->i_d.di_nextents == 0);
2425 	ASSERT(ip->i_d.di_anextents == 0);
2426 	ASSERT(ip->i_d.di_size == 0 || !S_ISREG(VFS_I(ip)->i_mode));
2427 	ASSERT(ip->i_d.di_nblocks == 0);
2428 
2429 	/*
2430 	 * Pull the on-disk inode from the AGI unlinked list.
2431 	 */
2432 	error = xfs_iunlink_remove(tp, ip);
2433 	if (error)
2434 		return error;
2435 
2436 	error = xfs_difree(tp, ip->i_ino, dfops, &xic);
2437 	if (error)
2438 		return error;
2439 
2440 	VFS_I(ip)->i_mode = 0;		/* mark incore inode as free */
2441 	ip->i_d.di_flags = 0;
2442 	ip->i_d.di_dmevmask = 0;
2443 	ip->i_d.di_forkoff = 0;		/* mark the attr fork not in use */
2444 	ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
2445 	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
2446 	/*
2447 	 * Bump the generation count so no one will be confused
2448 	 * by reincarnations of this inode.
2449 	 */
2450 	VFS_I(ip)->i_generation++;
2451 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2452 
2453 	if (xic.deleted)
2454 		error = xfs_ifree_cluster(ip, tp, &xic);
2455 
2456 	return error;
2457 }
2458 
2459 /*
2460  * This is called to unpin an inode.  The caller must have the inode locked
2461  * in at least shared mode so that the buffer cannot be subsequently pinned
2462  * once someone is waiting for it to be unpinned.
2463  */
2464 static void
2465 xfs_iunpin(
2466 	struct xfs_inode	*ip)
2467 {
2468 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
2469 
2470 	trace_xfs_inode_unpin_nowait(ip, _RET_IP_);
2471 
2472 	/* Give the log a push to start the unpinning I/O */
2473 	xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0);
2474 
2475 }
2476 
2477 static void
2478 __xfs_iunpin_wait(
2479 	struct xfs_inode	*ip)
2480 {
2481 	wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IPINNED_BIT);
2482 	DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IPINNED_BIT);
2483 
2484 	xfs_iunpin(ip);
2485 
2486 	do {
2487 		prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
2488 		if (xfs_ipincount(ip))
2489 			io_schedule();
2490 	} while (xfs_ipincount(ip));
2491 	finish_wait(wq, &wait.wq_entry);
2492 }
2493 
2494 void
2495 xfs_iunpin_wait(
2496 	struct xfs_inode	*ip)
2497 {
2498 	if (xfs_ipincount(ip))
2499 		__xfs_iunpin_wait(ip);
2500 }
2501 
2502 /*
2503  * Removing an inode from the namespace involves removing the directory entry
2504  * and dropping the link count on the inode. Removing the directory entry can
2505  * result in locking an AGF (directory blocks were freed) and removing a link
2506  * count can result in placing the inode on an unlinked list which results in
2507  * locking an AGI.
2508  *
2509  * The big problem here is that we have an ordering constraint on AGF and AGI
2510  * locking - inode allocation locks the AGI, then can allocate a new extent for
2511  * new inodes, locking the AGF after the AGI. Similarly, freeing the inode
2512  * removes the inode from the unlinked list, requiring that we lock the AGI
2513  * first, and then freeing the inode can result in an inode chunk being freed
2514  * and hence freeing disk space requiring that we lock an AGF.
2515  *
2516  * Hence the ordering that is imposed by other parts of the code is AGI before
2517  * AGF. This means we cannot remove the directory entry before we drop the inode
2518  * reference count and put it on the unlinked list as this results in a lock
2519  * order of AGF then AGI, and this can deadlock against inode allocation and
2520  * freeing. Therefore we must drop the link counts before we remove the
2521  * directory entry.
2522  *
2523  * This is still safe from a transactional point of view - it is not until we
2524  * get to xfs_defer_finish() that we have the possibility of multiple
2525  * transactions in this operation. Hence as long as we remove the directory
2526  * entry and drop the link count in the first transaction of the remove
2527  * operation, there are no transactional constraints on the ordering here.
2528  */
2529 int
2530 xfs_remove(
2531 	xfs_inode_t             *dp,
2532 	struct xfs_name		*name,
2533 	xfs_inode_t		*ip)
2534 {
2535 	xfs_mount_t		*mp = dp->i_mount;
2536 	xfs_trans_t             *tp = NULL;
2537 	int			is_dir = S_ISDIR(VFS_I(ip)->i_mode);
2538 	int                     error = 0;
2539 	struct xfs_defer_ops	dfops;
2540 	xfs_fsblock_t           first_block;
2541 	uint			resblks;
2542 
2543 	trace_xfs_remove(dp, name);
2544 
2545 	if (XFS_FORCED_SHUTDOWN(mp))
2546 		return -EIO;
2547 
2548 	error = xfs_qm_dqattach(dp, 0);
2549 	if (error)
2550 		goto std_return;
2551 
2552 	error = xfs_qm_dqattach(ip, 0);
2553 	if (error)
2554 		goto std_return;
2555 
2556 	/*
2557 	 * We try to get the real space reservation first,
2558 	 * allowing for directory btree deletion(s) implying
2559 	 * possible bmap insert(s).  If we can't get the space
2560 	 * reservation then we use 0 instead, and avoid the bmap
2561 	 * btree insert(s) in the directory code by, if the bmap
2562 	 * insert tries to happen, instead trimming the LAST
2563 	 * block from the directory.
2564 	 */
2565 	resblks = XFS_REMOVE_SPACE_RES(mp);
2566 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, resblks, 0, 0, &tp);
2567 	if (error == -ENOSPC) {
2568 		resblks = 0;
2569 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, 0, 0, 0,
2570 				&tp);
2571 	}
2572 	if (error) {
2573 		ASSERT(error != -ENOSPC);
2574 		goto std_return;
2575 	}
2576 
2577 	xfs_lock_two_inodes(dp, ip, XFS_ILOCK_EXCL);
2578 
2579 	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
2580 	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
2581 
2582 	/*
2583 	 * If we're removing a directory perform some additional validation.
2584 	 */
2585 	if (is_dir) {
2586 		ASSERT(VFS_I(ip)->i_nlink >= 2);
2587 		if (VFS_I(ip)->i_nlink != 2) {
2588 			error = -ENOTEMPTY;
2589 			goto out_trans_cancel;
2590 		}
2591 		if (!xfs_dir_isempty(ip)) {
2592 			error = -ENOTEMPTY;
2593 			goto out_trans_cancel;
2594 		}
2595 
2596 		/* Drop the link from ip's "..".  */
2597 		error = xfs_droplink(tp, dp);
2598 		if (error)
2599 			goto out_trans_cancel;
2600 
2601 		/* Drop the "." link from ip to self.  */
2602 		error = xfs_droplink(tp, ip);
2603 		if (error)
2604 			goto out_trans_cancel;
2605 	} else {
2606 		/*
2607 		 * When removing a non-directory we need to log the parent
2608 		 * inode here.  For a directory this is done implicitly
2609 		 * by the xfs_droplink call for the ".." entry.
2610 		 */
2611 		xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
2612 	}
2613 	xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2614 
2615 	/* Drop the link from dp to ip. */
2616 	error = xfs_droplink(tp, ip);
2617 	if (error)
2618 		goto out_trans_cancel;
2619 
2620 	xfs_defer_init(&dfops, &first_block);
2621 	error = xfs_dir_removename(tp, dp, name, ip->i_ino,
2622 					&first_block, &dfops, resblks);
2623 	if (error) {
2624 		ASSERT(error != -ENOENT);
2625 		goto out_bmap_cancel;
2626 	}
2627 
2628 	/*
2629 	 * If this is a synchronous mount, make sure that the
2630 	 * remove transaction goes to disk before returning to
2631 	 * the user.
2632 	 */
2633 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2634 		xfs_trans_set_sync(tp);
2635 
2636 	error = xfs_defer_finish(&tp, &dfops);
2637 	if (error)
2638 		goto out_bmap_cancel;
2639 
2640 	error = xfs_trans_commit(tp);
2641 	if (error)
2642 		goto std_return;
2643 
2644 	if (is_dir && xfs_inode_is_filestream(ip))
2645 		xfs_filestream_deassociate(ip);
2646 
2647 	return 0;
2648 
2649  out_bmap_cancel:
2650 	xfs_defer_cancel(&dfops);
2651  out_trans_cancel:
2652 	xfs_trans_cancel(tp);
2653  std_return:
2654 	return error;
2655 }
2656 
2657 /*
2658  * Enter all inodes for a rename transaction into a sorted array.
2659  */
2660 #define __XFS_SORT_INODES	5
2661 STATIC void
2662 xfs_sort_for_rename(
2663 	struct xfs_inode	*dp1,	/* in: old (source) directory inode */
2664 	struct xfs_inode	*dp2,	/* in: new (target) directory inode */
2665 	struct xfs_inode	*ip1,	/* in: inode of old entry */
2666 	struct xfs_inode	*ip2,	/* in: inode of new entry */
2667 	struct xfs_inode	*wip,	/* in: whiteout inode */
2668 	struct xfs_inode	**i_tab,/* out: sorted array of inodes */
2669 	int			*num_inodes)  /* in/out: inodes in array */
2670 {
2671 	int			i, j;
2672 
2673 	ASSERT(*num_inodes == __XFS_SORT_INODES);
2674 	memset(i_tab, 0, *num_inodes * sizeof(struct xfs_inode *));
2675 
2676 	/*
2677 	 * i_tab contains a list of pointers to inodes.  We initialize
2678 	 * the table here & we'll sort it.  We will then use it to
2679 	 * order the acquisition of the inode locks.
2680 	 *
2681 	 * Note that the table may contain duplicates.  e.g., dp1 == dp2.
2682 	 */
2683 	i = 0;
2684 	i_tab[i++] = dp1;
2685 	i_tab[i++] = dp2;
2686 	i_tab[i++] = ip1;
2687 	if (ip2)
2688 		i_tab[i++] = ip2;
2689 	if (wip)
2690 		i_tab[i++] = wip;
2691 	*num_inodes = i;
2692 
2693 	/*
2694 	 * Sort the elements via bubble sort.  (Remember, there are at
2695 	 * most 5 elements to sort, so this is adequate.)
2696 	 */
2697 	for (i = 0; i < *num_inodes; i++) {
2698 		for (j = 1; j < *num_inodes; j++) {
2699 			if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
2700 				struct xfs_inode *temp = i_tab[j];
2701 				i_tab[j] = i_tab[j-1];
2702 				i_tab[j-1] = temp;
2703 			}
2704 		}
2705 	}
2706 }
2707 
2708 static int
2709 xfs_finish_rename(
2710 	struct xfs_trans	*tp,
2711 	struct xfs_defer_ops	*dfops)
2712 {
2713 	int			error;
2714 
2715 	/*
2716 	 * If this is a synchronous mount, make sure that the rename transaction
2717 	 * goes to disk before returning to the user.
2718 	 */
2719 	if (tp->t_mountp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2720 		xfs_trans_set_sync(tp);
2721 
2722 	error = xfs_defer_finish(&tp, dfops);
2723 	if (error) {
2724 		xfs_defer_cancel(dfops);
2725 		xfs_trans_cancel(tp);
2726 		return error;
2727 	}
2728 
2729 	return xfs_trans_commit(tp);
2730 }
2731 
2732 /*
2733  * xfs_cross_rename()
2734  *
2735  * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall
2736  */
2737 STATIC int
2738 xfs_cross_rename(
2739 	struct xfs_trans	*tp,
2740 	struct xfs_inode	*dp1,
2741 	struct xfs_name		*name1,
2742 	struct xfs_inode	*ip1,
2743 	struct xfs_inode	*dp2,
2744 	struct xfs_name		*name2,
2745 	struct xfs_inode	*ip2,
2746 	struct xfs_defer_ops	*dfops,
2747 	xfs_fsblock_t		*first_block,
2748 	int			spaceres)
2749 {
2750 	int		error = 0;
2751 	int		ip1_flags = 0;
2752 	int		ip2_flags = 0;
2753 	int		dp2_flags = 0;
2754 
2755 	/* Swap inode number for dirent in first parent */
2756 	error = xfs_dir_replace(tp, dp1, name1,
2757 				ip2->i_ino,
2758 				first_block, dfops, spaceres);
2759 	if (error)
2760 		goto out_trans_abort;
2761 
2762 	/* Swap inode number for dirent in second parent */
2763 	error = xfs_dir_replace(tp, dp2, name2,
2764 				ip1->i_ino,
2765 				first_block, dfops, spaceres);
2766 	if (error)
2767 		goto out_trans_abort;
2768 
2769 	/*
2770 	 * If we're renaming one or more directories across different parents,
2771 	 * update the respective ".." entries (and link counts) to match the new
2772 	 * parents.
2773 	 */
2774 	if (dp1 != dp2) {
2775 		dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2776 
2777 		if (S_ISDIR(VFS_I(ip2)->i_mode)) {
2778 			error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
2779 						dp1->i_ino, first_block,
2780 						dfops, spaceres);
2781 			if (error)
2782 				goto out_trans_abort;
2783 
2784 			/* transfer ip2 ".." reference to dp1 */
2785 			if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
2786 				error = xfs_droplink(tp, dp2);
2787 				if (error)
2788 					goto out_trans_abort;
2789 				error = xfs_bumplink(tp, dp1);
2790 				if (error)
2791 					goto out_trans_abort;
2792 			}
2793 
2794 			/*
2795 			 * Although ip1 isn't changed here, userspace needs
2796 			 * to be warned about the change, so that applications
2797 			 * relying on it (like backup ones), will properly
2798 			 * notify the change
2799 			 */
2800 			ip1_flags |= XFS_ICHGTIME_CHG;
2801 			ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2802 		}
2803 
2804 		if (S_ISDIR(VFS_I(ip1)->i_mode)) {
2805 			error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
2806 						dp2->i_ino, first_block,
2807 						dfops, spaceres);
2808 			if (error)
2809 				goto out_trans_abort;
2810 
2811 			/* transfer ip1 ".." reference to dp2 */
2812 			if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
2813 				error = xfs_droplink(tp, dp1);
2814 				if (error)
2815 					goto out_trans_abort;
2816 				error = xfs_bumplink(tp, dp2);
2817 				if (error)
2818 					goto out_trans_abort;
2819 			}
2820 
2821 			/*
2822 			 * Although ip2 isn't changed here, userspace needs
2823 			 * to be warned about the change, so that applications
2824 			 * relying on it (like backup ones), will properly
2825 			 * notify the change
2826 			 */
2827 			ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2828 			ip2_flags |= XFS_ICHGTIME_CHG;
2829 		}
2830 	}
2831 
2832 	if (ip1_flags) {
2833 		xfs_trans_ichgtime(tp, ip1, ip1_flags);
2834 		xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
2835 	}
2836 	if (ip2_flags) {
2837 		xfs_trans_ichgtime(tp, ip2, ip2_flags);
2838 		xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
2839 	}
2840 	if (dp2_flags) {
2841 		xfs_trans_ichgtime(tp, dp2, dp2_flags);
2842 		xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
2843 	}
2844 	xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2845 	xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
2846 	return xfs_finish_rename(tp, dfops);
2847 
2848 out_trans_abort:
2849 	xfs_defer_cancel(dfops);
2850 	xfs_trans_cancel(tp);
2851 	return error;
2852 }
2853 
2854 /*
2855  * xfs_rename_alloc_whiteout()
2856  *
2857  * Return a referenced, unlinked, unlocked inode that that can be used as a
2858  * whiteout in a rename transaction. We use a tmpfile inode here so that if we
2859  * crash between allocating the inode and linking it into the rename transaction
2860  * recovery will free the inode and we won't leak it.
2861  */
2862 static int
2863 xfs_rename_alloc_whiteout(
2864 	struct xfs_inode	*dp,
2865 	struct xfs_inode	**wip)
2866 {
2867 	struct xfs_inode	*tmpfile;
2868 	int			error;
2869 
2870 	error = xfs_create_tmpfile(dp, NULL, S_IFCHR | WHITEOUT_MODE, &tmpfile);
2871 	if (error)
2872 		return error;
2873 
2874 	/*
2875 	 * Prepare the tmpfile inode as if it were created through the VFS.
2876 	 * Otherwise, the link increment paths will complain about nlink 0->1.
2877 	 * Drop the link count as done by d_tmpfile(), complete the inode setup
2878 	 * and flag it as linkable.
2879 	 */
2880 	drop_nlink(VFS_I(tmpfile));
2881 	xfs_setup_iops(tmpfile);
2882 	xfs_finish_inode_setup(tmpfile);
2883 	VFS_I(tmpfile)->i_state |= I_LINKABLE;
2884 
2885 	*wip = tmpfile;
2886 	return 0;
2887 }
2888 
2889 /*
2890  * xfs_rename
2891  */
2892 int
2893 xfs_rename(
2894 	struct xfs_inode	*src_dp,
2895 	struct xfs_name		*src_name,
2896 	struct xfs_inode	*src_ip,
2897 	struct xfs_inode	*target_dp,
2898 	struct xfs_name		*target_name,
2899 	struct xfs_inode	*target_ip,
2900 	unsigned int		flags)
2901 {
2902 	struct xfs_mount	*mp = src_dp->i_mount;
2903 	struct xfs_trans	*tp;
2904 	struct xfs_defer_ops	dfops;
2905 	xfs_fsblock_t		first_block;
2906 	struct xfs_inode	*wip = NULL;		/* whiteout inode */
2907 	struct xfs_inode	*inodes[__XFS_SORT_INODES];
2908 	int			num_inodes = __XFS_SORT_INODES;
2909 	bool			new_parent = (src_dp != target_dp);
2910 	bool			src_is_directory = S_ISDIR(VFS_I(src_ip)->i_mode);
2911 	int			spaceres;
2912 	int			error;
2913 
2914 	trace_xfs_rename(src_dp, target_dp, src_name, target_name);
2915 
2916 	if ((flags & RENAME_EXCHANGE) && !target_ip)
2917 		return -EINVAL;
2918 
2919 	/*
2920 	 * If we are doing a whiteout operation, allocate the whiteout inode
2921 	 * we will be placing at the target and ensure the type is set
2922 	 * appropriately.
2923 	 */
2924 	if (flags & RENAME_WHITEOUT) {
2925 		ASSERT(!(flags & (RENAME_NOREPLACE | RENAME_EXCHANGE)));
2926 		error = xfs_rename_alloc_whiteout(target_dp, &wip);
2927 		if (error)
2928 			return error;
2929 
2930 		/* setup target dirent info as whiteout */
2931 		src_name->type = XFS_DIR3_FT_CHRDEV;
2932 	}
2933 
2934 	xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip, wip,
2935 				inodes, &num_inodes);
2936 
2937 	spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
2938 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, spaceres, 0, 0, &tp);
2939 	if (error == -ENOSPC) {
2940 		spaceres = 0;
2941 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, 0, 0, 0,
2942 				&tp);
2943 	}
2944 	if (error)
2945 		goto out_release_wip;
2946 
2947 	/*
2948 	 * Attach the dquots to the inodes
2949 	 */
2950 	error = xfs_qm_vop_rename_dqattach(inodes);
2951 	if (error)
2952 		goto out_trans_cancel;
2953 
2954 	/*
2955 	 * Lock all the participating inodes. Depending upon whether
2956 	 * the target_name exists in the target directory, and
2957 	 * whether the target directory is the same as the source
2958 	 * directory, we can lock from 2 to 4 inodes.
2959 	 */
2960 	xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
2961 
2962 	/*
2963 	 * Join all the inodes to the transaction. From this point on,
2964 	 * we can rely on either trans_commit or trans_cancel to unlock
2965 	 * them.
2966 	 */
2967 	xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
2968 	if (new_parent)
2969 		xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
2970 	xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
2971 	if (target_ip)
2972 		xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
2973 	if (wip)
2974 		xfs_trans_ijoin(tp, wip, XFS_ILOCK_EXCL);
2975 
2976 	/*
2977 	 * If we are using project inheritance, we only allow renames
2978 	 * into our tree when the project IDs are the same; else the
2979 	 * tree quota mechanism would be circumvented.
2980 	 */
2981 	if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
2982 		     (xfs_get_projid(target_dp) != xfs_get_projid(src_ip)))) {
2983 		error = -EXDEV;
2984 		goto out_trans_cancel;
2985 	}
2986 
2987 	xfs_defer_init(&dfops, &first_block);
2988 
2989 	/* RENAME_EXCHANGE is unique from here on. */
2990 	if (flags & RENAME_EXCHANGE)
2991 		return xfs_cross_rename(tp, src_dp, src_name, src_ip,
2992 					target_dp, target_name, target_ip,
2993 					&dfops, &first_block, spaceres);
2994 
2995 	/*
2996 	 * Set up the target.
2997 	 */
2998 	if (target_ip == NULL) {
2999 		/*
3000 		 * If there's no space reservation, check the entry will
3001 		 * fit before actually inserting it.
3002 		 */
3003 		if (!spaceres) {
3004 			error = xfs_dir_canenter(tp, target_dp, target_name);
3005 			if (error)
3006 				goto out_trans_cancel;
3007 		}
3008 		/*
3009 		 * If target does not exist and the rename crosses
3010 		 * directories, adjust the target directory link count
3011 		 * to account for the ".." reference from the new entry.
3012 		 */
3013 		error = xfs_dir_createname(tp, target_dp, target_name,
3014 						src_ip->i_ino, &first_block,
3015 						&dfops, spaceres);
3016 		if (error)
3017 			goto out_bmap_cancel;
3018 
3019 		xfs_trans_ichgtime(tp, target_dp,
3020 					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3021 
3022 		if (new_parent && src_is_directory) {
3023 			error = xfs_bumplink(tp, target_dp);
3024 			if (error)
3025 				goto out_bmap_cancel;
3026 		}
3027 	} else { /* target_ip != NULL */
3028 		/*
3029 		 * If target exists and it's a directory, check that both
3030 		 * target and source are directories and that target can be
3031 		 * destroyed, or that neither is a directory.
3032 		 */
3033 		if (S_ISDIR(VFS_I(target_ip)->i_mode)) {
3034 			/*
3035 			 * Make sure target dir is empty.
3036 			 */
3037 			if (!(xfs_dir_isempty(target_ip)) ||
3038 			    (VFS_I(target_ip)->i_nlink > 2)) {
3039 				error = -EEXIST;
3040 				goto out_trans_cancel;
3041 			}
3042 		}
3043 
3044 		/*
3045 		 * Link the source inode under the target name.
3046 		 * If the source inode is a directory and we are moving
3047 		 * it across directories, its ".." entry will be
3048 		 * inconsistent until we replace that down below.
3049 		 *
3050 		 * In case there is already an entry with the same
3051 		 * name at the destination directory, remove it first.
3052 		 */
3053 		error = xfs_dir_replace(tp, target_dp, target_name,
3054 					src_ip->i_ino,
3055 					&first_block, &dfops, spaceres);
3056 		if (error)
3057 			goto out_bmap_cancel;
3058 
3059 		xfs_trans_ichgtime(tp, target_dp,
3060 					XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3061 
3062 		/*
3063 		 * Decrement the link count on the target since the target
3064 		 * dir no longer points to it.
3065 		 */
3066 		error = xfs_droplink(tp, target_ip);
3067 		if (error)
3068 			goto out_bmap_cancel;
3069 
3070 		if (src_is_directory) {
3071 			/*
3072 			 * Drop the link from the old "." entry.
3073 			 */
3074 			error = xfs_droplink(tp, target_ip);
3075 			if (error)
3076 				goto out_bmap_cancel;
3077 		}
3078 	} /* target_ip != NULL */
3079 
3080 	/*
3081 	 * Remove the source.
3082 	 */
3083 	if (new_parent && src_is_directory) {
3084 		/*
3085 		 * Rewrite the ".." entry to point to the new
3086 		 * directory.
3087 		 */
3088 		error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
3089 					target_dp->i_ino,
3090 					&first_block, &dfops, spaceres);
3091 		ASSERT(error != -EEXIST);
3092 		if (error)
3093 			goto out_bmap_cancel;
3094 	}
3095 
3096 	/*
3097 	 * We always want to hit the ctime on the source inode.
3098 	 *
3099 	 * This isn't strictly required by the standards since the source
3100 	 * inode isn't really being changed, but old unix file systems did
3101 	 * it and some incremental backup programs won't work without it.
3102 	 */
3103 	xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
3104 	xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
3105 
3106 	/*
3107 	 * Adjust the link count on src_dp.  This is necessary when
3108 	 * renaming a directory, either within one parent when
3109 	 * the target existed, or across two parent directories.
3110 	 */
3111 	if (src_is_directory && (new_parent || target_ip != NULL)) {
3112 
3113 		/*
3114 		 * Decrement link count on src_directory since the
3115 		 * entry that's moved no longer points to it.
3116 		 */
3117 		error = xfs_droplink(tp, src_dp);
3118 		if (error)
3119 			goto out_bmap_cancel;
3120 	}
3121 
3122 	/*
3123 	 * For whiteouts, we only need to update the source dirent with the
3124 	 * inode number of the whiteout inode rather than removing it
3125 	 * altogether.
3126 	 */
3127 	if (wip) {
3128 		error = xfs_dir_replace(tp, src_dp, src_name, wip->i_ino,
3129 					&first_block, &dfops, spaceres);
3130 	} else
3131 		error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
3132 					   &first_block, &dfops, spaceres);
3133 	if (error)
3134 		goto out_bmap_cancel;
3135 
3136 	/*
3137 	 * For whiteouts, we need to bump the link count on the whiteout inode.
3138 	 * This means that failures all the way up to this point leave the inode
3139 	 * on the unlinked list and so cleanup is a simple matter of dropping
3140 	 * the remaining reference to it. If we fail here after bumping the link
3141 	 * count, we're shutting down the filesystem so we'll never see the
3142 	 * intermediate state on disk.
3143 	 */
3144 	if (wip) {
3145 		ASSERT(VFS_I(wip)->i_nlink == 0);
3146 		error = xfs_bumplink(tp, wip);
3147 		if (error)
3148 			goto out_bmap_cancel;
3149 		error = xfs_iunlink_remove(tp, wip);
3150 		if (error)
3151 			goto out_bmap_cancel;
3152 		xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE);
3153 
3154 		/*
3155 		 * Now we have a real link, clear the "I'm a tmpfile" state
3156 		 * flag from the inode so it doesn't accidentally get misused in
3157 		 * future.
3158 		 */
3159 		VFS_I(wip)->i_state &= ~I_LINKABLE;
3160 	}
3161 
3162 	xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3163 	xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
3164 	if (new_parent)
3165 		xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
3166 
3167 	error = xfs_finish_rename(tp, &dfops);
3168 	if (wip)
3169 		IRELE(wip);
3170 	return error;
3171 
3172 out_bmap_cancel:
3173 	xfs_defer_cancel(&dfops);
3174 out_trans_cancel:
3175 	xfs_trans_cancel(tp);
3176 out_release_wip:
3177 	if (wip)
3178 		IRELE(wip);
3179 	return error;
3180 }
3181 
3182 STATIC int
3183 xfs_iflush_cluster(
3184 	struct xfs_inode	*ip,
3185 	struct xfs_buf		*bp)
3186 {
3187 	struct xfs_mount	*mp = ip->i_mount;
3188 	struct xfs_perag	*pag;
3189 	unsigned long		first_index, mask;
3190 	unsigned long		inodes_per_cluster;
3191 	int			cilist_size;
3192 	struct xfs_inode	**cilist;
3193 	struct xfs_inode	*cip;
3194 	int			nr_found;
3195 	int			clcount = 0;
3196 	int			bufwasdelwri;
3197 	int			i;
3198 
3199 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
3200 
3201 	inodes_per_cluster = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;
3202 	cilist_size = inodes_per_cluster * sizeof(xfs_inode_t *);
3203 	cilist = kmem_alloc(cilist_size, KM_MAYFAIL|KM_NOFS);
3204 	if (!cilist)
3205 		goto out_put;
3206 
3207 	mask = ~(((mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog)) - 1);
3208 	first_index = XFS_INO_TO_AGINO(mp, ip->i_ino) & mask;
3209 	rcu_read_lock();
3210 	/* really need a gang lookup range call here */
3211 	nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void**)cilist,
3212 					first_index, inodes_per_cluster);
3213 	if (nr_found == 0)
3214 		goto out_free;
3215 
3216 	for (i = 0; i < nr_found; i++) {
3217 		cip = cilist[i];
3218 		if (cip == ip)
3219 			continue;
3220 
3221 		/*
3222 		 * because this is an RCU protected lookup, we could find a
3223 		 * recently freed or even reallocated inode during the lookup.
3224 		 * We need to check under the i_flags_lock for a valid inode
3225 		 * here. Skip it if it is not valid or the wrong inode.
3226 		 */
3227 		spin_lock(&cip->i_flags_lock);
3228 		if (!cip->i_ino ||
3229 		    __xfs_iflags_test(cip, XFS_ISTALE)) {
3230 			spin_unlock(&cip->i_flags_lock);
3231 			continue;
3232 		}
3233 
3234 		/*
3235 		 * Once we fall off the end of the cluster, no point checking
3236 		 * any more inodes in the list because they will also all be
3237 		 * outside the cluster.
3238 		 */
3239 		if ((XFS_INO_TO_AGINO(mp, cip->i_ino) & mask) != first_index) {
3240 			spin_unlock(&cip->i_flags_lock);
3241 			break;
3242 		}
3243 		spin_unlock(&cip->i_flags_lock);
3244 
3245 		/*
3246 		 * Do an un-protected check to see if the inode is dirty and
3247 		 * is a candidate for flushing.  These checks will be repeated
3248 		 * later after the appropriate locks are acquired.
3249 		 */
3250 		if (xfs_inode_clean(cip) && xfs_ipincount(cip) == 0)
3251 			continue;
3252 
3253 		/*
3254 		 * Try to get locks.  If any are unavailable or it is pinned,
3255 		 * then this inode cannot be flushed and is skipped.
3256 		 */
3257 
3258 		if (!xfs_ilock_nowait(cip, XFS_ILOCK_SHARED))
3259 			continue;
3260 		if (!xfs_iflock_nowait(cip)) {
3261 			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3262 			continue;
3263 		}
3264 		if (xfs_ipincount(cip)) {
3265 			xfs_ifunlock(cip);
3266 			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3267 			continue;
3268 		}
3269 
3270 
3271 		/*
3272 		 * Check the inode number again, just to be certain we are not
3273 		 * racing with freeing in xfs_reclaim_inode(). See the comments
3274 		 * in that function for more information as to why the initial
3275 		 * check is not sufficient.
3276 		 */
3277 		if (!cip->i_ino) {
3278 			xfs_ifunlock(cip);
3279 			xfs_iunlock(cip, XFS_ILOCK_SHARED);
3280 			continue;
3281 		}
3282 
3283 		/*
3284 		 * arriving here means that this inode can be flushed.  First
3285 		 * re-check that it's dirty before flushing.
3286 		 */
3287 		if (!xfs_inode_clean(cip)) {
3288 			int	error;
3289 			error = xfs_iflush_int(cip, bp);
3290 			if (error) {
3291 				xfs_iunlock(cip, XFS_ILOCK_SHARED);
3292 				goto cluster_corrupt_out;
3293 			}
3294 			clcount++;
3295 		} else {
3296 			xfs_ifunlock(cip);
3297 		}
3298 		xfs_iunlock(cip, XFS_ILOCK_SHARED);
3299 	}
3300 
3301 	if (clcount) {
3302 		XFS_STATS_INC(mp, xs_icluster_flushcnt);
3303 		XFS_STATS_ADD(mp, xs_icluster_flushinode, clcount);
3304 	}
3305 
3306 out_free:
3307 	rcu_read_unlock();
3308 	kmem_free(cilist);
3309 out_put:
3310 	xfs_perag_put(pag);
3311 	return 0;
3312 
3313 
3314 cluster_corrupt_out:
3315 	/*
3316 	 * Corruption detected in the clustering loop.  Invalidate the
3317 	 * inode buffer and shut down the filesystem.
3318 	 */
3319 	rcu_read_unlock();
3320 	/*
3321 	 * Clean up the buffer.  If it was delwri, just release it --
3322 	 * brelse can handle it with no problems.  If not, shut down the
3323 	 * filesystem before releasing the buffer.
3324 	 */
3325 	bufwasdelwri = (bp->b_flags & _XBF_DELWRI_Q);
3326 	if (bufwasdelwri)
3327 		xfs_buf_relse(bp);
3328 
3329 	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3330 
3331 	if (!bufwasdelwri) {
3332 		/*
3333 		 * Just like incore_relse: if we have b_iodone functions,
3334 		 * mark the buffer as an error and call them.  Otherwise
3335 		 * mark it as stale and brelse.
3336 		 */
3337 		if (bp->b_iodone) {
3338 			bp->b_flags &= ~XBF_DONE;
3339 			xfs_buf_stale(bp);
3340 			xfs_buf_ioerror(bp, -EIO);
3341 			xfs_buf_ioend(bp);
3342 		} else {
3343 			xfs_buf_stale(bp);
3344 			xfs_buf_relse(bp);
3345 		}
3346 	}
3347 
3348 	/*
3349 	 * Unlocks the flush lock
3350 	 */
3351 	xfs_iflush_abort(cip, false);
3352 	kmem_free(cilist);
3353 	xfs_perag_put(pag);
3354 	return -EFSCORRUPTED;
3355 }
3356 
3357 /*
3358  * Flush dirty inode metadata into the backing buffer.
3359  *
3360  * The caller must have the inode lock and the inode flush lock held.  The
3361  * inode lock will still be held upon return to the caller, and the inode
3362  * flush lock will be released after the inode has reached the disk.
3363  *
3364  * The caller must write out the buffer returned in *bpp and release it.
3365  */
3366 int
3367 xfs_iflush(
3368 	struct xfs_inode	*ip,
3369 	struct xfs_buf		**bpp)
3370 {
3371 	struct xfs_mount	*mp = ip->i_mount;
3372 	struct xfs_buf		*bp = NULL;
3373 	struct xfs_dinode	*dip;
3374 	int			error;
3375 
3376 	XFS_STATS_INC(mp, xs_iflush_count);
3377 
3378 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3379 	ASSERT(xfs_isiflocked(ip));
3380 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3381 	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3382 
3383 	*bpp = NULL;
3384 
3385 	xfs_iunpin_wait(ip);
3386 
3387 	/*
3388 	 * For stale inodes we cannot rely on the backing buffer remaining
3389 	 * stale in cache for the remaining life of the stale inode and so
3390 	 * xfs_imap_to_bp() below may give us a buffer that no longer contains
3391 	 * inodes below. We have to check this after ensuring the inode is
3392 	 * unpinned so that it is safe to reclaim the stale inode after the
3393 	 * flush call.
3394 	 */
3395 	if (xfs_iflags_test(ip, XFS_ISTALE)) {
3396 		xfs_ifunlock(ip);
3397 		return 0;
3398 	}
3399 
3400 	/*
3401 	 * This may have been unpinned because the filesystem is shutting
3402 	 * down forcibly. If that's the case we must not write this inode
3403 	 * to disk, because the log record didn't make it to disk.
3404 	 *
3405 	 * We also have to remove the log item from the AIL in this case,
3406 	 * as we wait for an empty AIL as part of the unmount process.
3407 	 */
3408 	if (XFS_FORCED_SHUTDOWN(mp)) {
3409 		error = -EIO;
3410 		goto abort_out;
3411 	}
3412 
3413 	/*
3414 	 * Get the buffer containing the on-disk inode. We are doing a try-lock
3415 	 * operation here, so we may get  an EAGAIN error. In that case, we
3416 	 * simply want to return with the inode still dirty.
3417 	 *
3418 	 * If we get any other error, we effectively have a corruption situation
3419 	 * and we cannot flush the inode, so we treat it the same as failing
3420 	 * xfs_iflush_int().
3421 	 */
3422 	error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, XBF_TRYLOCK,
3423 			       0);
3424 	if (error == -EAGAIN) {
3425 		xfs_ifunlock(ip);
3426 		return error;
3427 	}
3428 	if (error)
3429 		goto corrupt_out;
3430 
3431 	/*
3432 	 * First flush out the inode that xfs_iflush was called with.
3433 	 */
3434 	error = xfs_iflush_int(ip, bp);
3435 	if (error)
3436 		goto corrupt_out;
3437 
3438 	/*
3439 	 * If the buffer is pinned then push on the log now so we won't
3440 	 * get stuck waiting in the write for too long.
3441 	 */
3442 	if (xfs_buf_ispinned(bp))
3443 		xfs_log_force(mp, 0);
3444 
3445 	/*
3446 	 * inode clustering:
3447 	 * see if other inodes can be gathered into this write
3448 	 */
3449 	error = xfs_iflush_cluster(ip, bp);
3450 	if (error)
3451 		goto cluster_corrupt_out;
3452 
3453 	*bpp = bp;
3454 	return 0;
3455 
3456 corrupt_out:
3457 	if (bp)
3458 		xfs_buf_relse(bp);
3459 	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3460 cluster_corrupt_out:
3461 	error = -EFSCORRUPTED;
3462 abort_out:
3463 	/*
3464 	 * Unlocks the flush lock
3465 	 */
3466 	xfs_iflush_abort(ip, false);
3467 	return error;
3468 }
3469 
3470 STATIC int
3471 xfs_iflush_int(
3472 	struct xfs_inode	*ip,
3473 	struct xfs_buf		*bp)
3474 {
3475 	struct xfs_inode_log_item *iip = ip->i_itemp;
3476 	struct xfs_dinode	*dip;
3477 	struct xfs_mount	*mp = ip->i_mount;
3478 
3479 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3480 	ASSERT(xfs_isiflocked(ip));
3481 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3482 	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3483 	ASSERT(iip != NULL && iip->ili_fields != 0);
3484 	ASSERT(ip->i_d.di_version > 1);
3485 
3486 	/* set *dip = inode's place in the buffer */
3487 	dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);
3488 
3489 	if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
3490 			       mp, XFS_ERRTAG_IFLUSH_1)) {
3491 		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3492 			"%s: Bad inode %Lu magic number 0x%x, ptr 0x%p",
3493 			__func__, ip->i_ino, be16_to_cpu(dip->di_magic), dip);
3494 		goto corrupt_out;
3495 	}
3496 	if (S_ISREG(VFS_I(ip)->i_mode)) {
3497 		if (XFS_TEST_ERROR(
3498 		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3499 		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
3500 		    mp, XFS_ERRTAG_IFLUSH_3)) {
3501 			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3502 				"%s: Bad regular inode %Lu, ptr 0x%p",
3503 				__func__, ip->i_ino, ip);
3504 			goto corrupt_out;
3505 		}
3506 	} else if (S_ISDIR(VFS_I(ip)->i_mode)) {
3507 		if (XFS_TEST_ERROR(
3508 		    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3509 		    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
3510 		    (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
3511 		    mp, XFS_ERRTAG_IFLUSH_4)) {
3512 			xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3513 				"%s: Bad directory inode %Lu, ptr 0x%p",
3514 				__func__, ip->i_ino, ip);
3515 			goto corrupt_out;
3516 		}
3517 	}
3518 	if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
3519 				ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5)) {
3520 		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3521 			"%s: detected corrupt incore inode %Lu, "
3522 			"total extents = %d, nblocks = %Ld, ptr 0x%p",
3523 			__func__, ip->i_ino,
3524 			ip->i_d.di_nextents + ip->i_d.di_anextents,
3525 			ip->i_d.di_nblocks, ip);
3526 		goto corrupt_out;
3527 	}
3528 	if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
3529 				mp, XFS_ERRTAG_IFLUSH_6)) {
3530 		xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3531 			"%s: bad inode %Lu, forkoff 0x%x, ptr 0x%p",
3532 			__func__, ip->i_ino, ip->i_d.di_forkoff, ip);
3533 		goto corrupt_out;
3534 	}
3535 
3536 	/*
3537 	 * Inode item log recovery for v2 inodes are dependent on the
3538 	 * di_flushiter count for correct sequencing. We bump the flush
3539 	 * iteration count so we can detect flushes which postdate a log record
3540 	 * during recovery. This is redundant as we now log every change and
3541 	 * hence this can't happen but we need to still do it to ensure
3542 	 * backwards compatibility with old kernels that predate logging all
3543 	 * inode changes.
3544 	 */
3545 	if (ip->i_d.di_version < 3)
3546 		ip->i_d.di_flushiter++;
3547 
3548 	/* Check the inline directory data. */
3549 	if (S_ISDIR(VFS_I(ip)->i_mode) &&
3550 	    ip->i_d.di_format == XFS_DINODE_FMT_LOCAL &&
3551 	    xfs_dir2_sf_verify(ip))
3552 		goto corrupt_out;
3553 
3554 	/*
3555 	 * Copy the dirty parts of the inode into the on-disk inode.  We always
3556 	 * copy out the core of the inode, because if the inode is dirty at all
3557 	 * the core must be.
3558 	 */
3559 	xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);
3560 
3561 	/* Wrap, we never let the log put out DI_MAX_FLUSH */
3562 	if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
3563 		ip->i_d.di_flushiter = 0;
3564 
3565 	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
3566 	if (XFS_IFORK_Q(ip))
3567 		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
3568 	xfs_inobp_check(mp, bp);
3569 
3570 	/*
3571 	 * We've recorded everything logged in the inode, so we'd like to clear
3572 	 * the ili_fields bits so we don't log and flush things unnecessarily.
3573 	 * However, we can't stop logging all this information until the data
3574 	 * we've copied into the disk buffer is written to disk.  If we did we
3575 	 * might overwrite the copy of the inode in the log with all the data
3576 	 * after re-logging only part of it, and in the face of a crash we
3577 	 * wouldn't have all the data we need to recover.
3578 	 *
3579 	 * What we do is move the bits to the ili_last_fields field.  When
3580 	 * logging the inode, these bits are moved back to the ili_fields field.
3581 	 * In the xfs_iflush_done() routine we clear ili_last_fields, since we
3582 	 * know that the information those bits represent is permanently on
3583 	 * disk.  As long as the flush completes before the inode is logged
3584 	 * again, then both ili_fields and ili_last_fields will be cleared.
3585 	 *
3586 	 * We can play with the ili_fields bits here, because the inode lock
3587 	 * must be held exclusively in order to set bits there and the flush
3588 	 * lock protects the ili_last_fields bits.  Set ili_logged so the flush
3589 	 * done routine can tell whether or not to look in the AIL.  Also, store
3590 	 * the current LSN of the inode so that we can tell whether the item has
3591 	 * moved in the AIL from xfs_iflush_done().  In order to read the lsn we
3592 	 * need the AIL lock, because it is a 64 bit value that cannot be read
3593 	 * atomically.
3594 	 */
3595 	iip->ili_last_fields = iip->ili_fields;
3596 	iip->ili_fields = 0;
3597 	iip->ili_fsync_fields = 0;
3598 	iip->ili_logged = 1;
3599 
3600 	xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
3601 				&iip->ili_item.li_lsn);
3602 
3603 	/*
3604 	 * Attach the function xfs_iflush_done to the inode's
3605 	 * buffer.  This will remove the inode from the AIL
3606 	 * and unlock the inode's flush lock when the inode is
3607 	 * completely written to disk.
3608 	 */
3609 	xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);
3610 
3611 	/* generate the checksum. */
3612 	xfs_dinode_calc_crc(mp, dip);
3613 
3614 	ASSERT(bp->b_fspriv != NULL);
3615 	ASSERT(bp->b_iodone != NULL);
3616 	return 0;
3617 
3618 corrupt_out:
3619 	return -EFSCORRUPTED;
3620 }
3621