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TOMOYO Linux Cross Reference
Linux/fs/xfs/xfs_inode.c

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  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 #include <linux/iversion.h>
 20 
 21 #include "xfs.h"
 22 #include "xfs_fs.h"
 23 #include "xfs_shared.h"
 24 #include "xfs_format.h"
 25 #include "xfs_log_format.h"
 26 #include "xfs_trans_resv.h"
 27 #include "xfs_sb.h"
 28 #include "xfs_mount.h"
 29 #include "xfs_defer.h"
 30 #include "xfs_inode.h"
 31 #include "xfs_da_format.h"
 32 #include "xfs_da_btree.h"
 33 #include "xfs_dir2.h"
 34 #include "xfs_attr_sf.h"
 35 #include "xfs_attr.h"
 36 #include "xfs_trans_space.h"
 37 #include "xfs_trans.h"
 38 #include "xfs_buf_item.h"
 39 #include "xfs_inode_item.h"
 40 #include "xfs_ialloc.h"
 41 #include "xfs_bmap.h"
 42 #include "xfs_bmap_util.h"
 43 #include "xfs_errortag.h"
 44 #include "xfs_error.h"
 45 #include "xfs_quota.h"
 46 #include "xfs_filestream.h"
 47 #include "xfs_cksum.h"
 48 #include "xfs_trace.h"
 49 #include "xfs_icache.h"
 50 #include "xfs_symlink.h"
 51 #include "xfs_trans_priv.h"
 52 #include "xfs_log.h"
 53 #include "xfs_bmap_btree.h"
 54 #include "xfs_reflink.h"
 55 #include "xfs_dir2_priv.h"
 56 
 57 kmem_zone_t *xfs_inode_zone;
 58 
 59 /*
 60  * Used in xfs_itruncate_extents().  This is the maximum number of extents
 61  * freed from a file in a single transaction.
 62  */
 63 #define XFS_ITRUNC_MAX_EXTENTS  2
 64 
 65 STATIC int xfs_iflush_int(struct xfs_inode *, struct xfs_buf *);
 66 STATIC int xfs_iunlink(struct xfs_trans *, struct xfs_inode *);
 67 STATIC int xfs_iunlink_remove(struct xfs_trans *, struct xfs_inode *);
 68 
 69 /*
 70  * helper function to extract extent size hint from inode
 71  */
 72 xfs_extlen_t
 73 xfs_get_extsz_hint(
 74         struct xfs_inode        *ip)
 75 {
 76         if ((ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE) && ip->i_d.di_extsize)
 77                 return ip->i_d.di_extsize;
 78         if (XFS_IS_REALTIME_INODE(ip))
 79                 return ip->i_mount->m_sb.sb_rextsize;
 80         return 0;
 81 }
 82 
 83 /*
 84  * Helper function to extract CoW extent size hint from inode.
 85  * Between the extent size hint and the CoW extent size hint, we
 86  * return the greater of the two.  If the value is zero (automatic),
 87  * use the default size.
 88  */
 89 xfs_extlen_t
 90 xfs_get_cowextsz_hint(
 91         struct xfs_inode        *ip)
 92 {
 93         xfs_extlen_t            a, b;
 94 
 95         a = 0;
 96         if (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
 97                 a = ip->i_d.di_cowextsize;
 98         b = xfs_get_extsz_hint(ip);
 99 
100         a = max(a, b);
101         if (a == 0)
102                 return XFS_DEFAULT_COWEXTSZ_HINT;
103         return a;
104 }
105 
106 /*
107  * These two are wrapper routines around the xfs_ilock() routine used to
108  * centralize some grungy code.  They are used in places that wish to lock the
109  * inode solely for reading the extents.  The reason these places can't just
110  * call xfs_ilock(ip, XFS_ILOCK_SHARED) is that the inode lock also guards to
111  * bringing in of the extents from disk for a file in b-tree format.  If the
112  * inode is in b-tree format, then we need to lock the inode exclusively until
113  * the extents are read in.  Locking it exclusively all the time would limit
114  * our parallelism unnecessarily, though.  What we do instead is check to see
115  * if the extents have been read in yet, and only lock the inode exclusively
116  * if they have not.
117  *
118  * The functions return a value which should be given to the corresponding
119  * xfs_iunlock() call.
120  */
121 uint
122 xfs_ilock_data_map_shared(
123         struct xfs_inode        *ip)
124 {
125         uint                    lock_mode = XFS_ILOCK_SHARED;
126 
127         if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
128             (ip->i_df.if_flags & XFS_IFEXTENTS) == 0)
129                 lock_mode = XFS_ILOCK_EXCL;
130         xfs_ilock(ip, lock_mode);
131         return lock_mode;
132 }
133 
134 uint
135 xfs_ilock_attr_map_shared(
136         struct xfs_inode        *ip)
137 {
138         uint                    lock_mode = XFS_ILOCK_SHARED;
139 
140         if (ip->i_d.di_aformat == XFS_DINODE_FMT_BTREE &&
141             (ip->i_afp->if_flags & XFS_IFEXTENTS) == 0)
142                 lock_mode = XFS_ILOCK_EXCL;
143         xfs_ilock(ip, lock_mode);
144         return lock_mode;
145 }
146 
147 /*
148  * In addition to i_rwsem in the VFS inode, the xfs inode contains 2
149  * multi-reader locks: i_mmap_lock and the i_lock.  This routine allows
150  * various combinations of the locks to be obtained.
151  *
152  * The 3 locks should always be ordered so that the IO lock is obtained first,
153  * the mmap lock second and the ilock last in order to prevent deadlock.
154  *
155  * Basic locking order:
156  *
157  * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock
158  *
159  * mmap_sem locking order:
160  *
161  * i_rwsem -> page lock -> mmap_sem
162  * mmap_sem -> i_mmap_lock -> page_lock
163  *
164  * The difference in mmap_sem locking order mean that we cannot hold the
165  * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can
166  * fault in pages during copy in/out (for buffered IO) or require the mmap_sem
167  * in get_user_pages() to map the user pages into the kernel address space for
168  * direct IO. Similarly the i_rwsem cannot be taken inside a page fault because
169  * page faults already hold the mmap_sem.
170  *
171  * Hence to serialise fully against both syscall and mmap based IO, we need to
172  * take both the i_rwsem and the i_mmap_lock. These locks should *only* be both
173  * taken in places where we need to invalidate the page cache in a race
174  * free manner (e.g. truncate, hole punch and other extent manipulation
175  * functions).
176  */
177 void
178 xfs_ilock(
179         xfs_inode_t             *ip,
180         uint                    lock_flags)
181 {
182         trace_xfs_ilock(ip, lock_flags, _RET_IP_);
183 
184         /*
185          * You can't set both SHARED and EXCL for the same lock,
186          * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
187          * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
188          */
189         ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
190                (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
191         ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
192                (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
193         ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
194                (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
195         ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
196 
197         if (lock_flags & XFS_IOLOCK_EXCL) {
198                 down_write_nested(&VFS_I(ip)->i_rwsem,
199                                   XFS_IOLOCK_DEP(lock_flags));
200         } else if (lock_flags & XFS_IOLOCK_SHARED) {
201                 down_read_nested(&VFS_I(ip)->i_rwsem,
202                                  XFS_IOLOCK_DEP(lock_flags));
203         }
204 
205         if (lock_flags & XFS_MMAPLOCK_EXCL)
206                 mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
207         else if (lock_flags & XFS_MMAPLOCK_SHARED)
208                 mraccess_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
209 
210         if (lock_flags & XFS_ILOCK_EXCL)
211                 mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
212         else if (lock_flags & XFS_ILOCK_SHARED)
213                 mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
214 }
215 
216 /*
217  * This is just like xfs_ilock(), except that the caller
218  * is guaranteed not to sleep.  It returns 1 if it gets
219  * the requested locks and 0 otherwise.  If the IO lock is
220  * obtained but the inode lock cannot be, then the IO lock
221  * is dropped before returning.
222  *
223  * ip -- the inode being locked
224  * lock_flags -- this parameter indicates the inode's locks to be
225  *       to be locked.  See the comment for xfs_ilock() for a list
226  *       of valid values.
227  */
228 int
229 xfs_ilock_nowait(
230         xfs_inode_t             *ip,
231         uint                    lock_flags)
232 {
233         trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
234 
235         /*
236          * You can't set both SHARED and EXCL for the same lock,
237          * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
238          * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
239          */
240         ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
241                (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
242         ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
243                (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
244         ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
245                (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
246         ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
247 
248         if (lock_flags & XFS_IOLOCK_EXCL) {
249                 if (!down_write_trylock(&VFS_I(ip)->i_rwsem))
250                         goto out;
251         } else if (lock_flags & XFS_IOLOCK_SHARED) {
252                 if (!down_read_trylock(&VFS_I(ip)->i_rwsem))
253                         goto out;
254         }
255 
256         if (lock_flags & XFS_MMAPLOCK_EXCL) {
257                 if (!mrtryupdate(&ip->i_mmaplock))
258                         goto out_undo_iolock;
259         } else if (lock_flags & XFS_MMAPLOCK_SHARED) {
260                 if (!mrtryaccess(&ip->i_mmaplock))
261                         goto out_undo_iolock;
262         }
263 
264         if (lock_flags & XFS_ILOCK_EXCL) {
265                 if (!mrtryupdate(&ip->i_lock))
266                         goto out_undo_mmaplock;
267         } else if (lock_flags & XFS_ILOCK_SHARED) {
268                 if (!mrtryaccess(&ip->i_lock))
269                         goto out_undo_mmaplock;
270         }
271         return 1;
272 
273 out_undo_mmaplock:
274         if (lock_flags & XFS_MMAPLOCK_EXCL)
275                 mrunlock_excl(&ip->i_mmaplock);
276         else if (lock_flags & XFS_MMAPLOCK_SHARED)
277                 mrunlock_shared(&ip->i_mmaplock);
278 out_undo_iolock:
279         if (lock_flags & XFS_IOLOCK_EXCL)
280                 up_write(&VFS_I(ip)->i_rwsem);
281         else if (lock_flags & XFS_IOLOCK_SHARED)
282                 up_read(&VFS_I(ip)->i_rwsem);
283 out:
284         return 0;
285 }
286 
287 /*
288  * xfs_iunlock() is used to drop the inode locks acquired with
289  * xfs_ilock() and xfs_ilock_nowait().  The caller must pass
290  * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
291  * that we know which locks to drop.
292  *
293  * ip -- the inode being unlocked
294  * lock_flags -- this parameter indicates the inode's locks to be
295  *       to be unlocked.  See the comment for xfs_ilock() for a list
296  *       of valid values for this parameter.
297  *
298  */
299 void
300 xfs_iunlock(
301         xfs_inode_t             *ip,
302         uint                    lock_flags)
303 {
304         /*
305          * You can't set both SHARED and EXCL for the same lock,
306          * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
307          * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
308          */
309         ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
310                (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
311         ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) !=
312                (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL));
313         ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
314                (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
315         ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
316         ASSERT(lock_flags != 0);
317 
318         if (lock_flags & XFS_IOLOCK_EXCL)
319                 up_write(&VFS_I(ip)->i_rwsem);
320         else if (lock_flags & XFS_IOLOCK_SHARED)
321                 up_read(&VFS_I(ip)->i_rwsem);
322 
323         if (lock_flags & XFS_MMAPLOCK_EXCL)
324                 mrunlock_excl(&ip->i_mmaplock);
325         else if (lock_flags & XFS_MMAPLOCK_SHARED)
326                 mrunlock_shared(&ip->i_mmaplock);
327 
328         if (lock_flags & XFS_ILOCK_EXCL)
329                 mrunlock_excl(&ip->i_lock);
330         else if (lock_flags & XFS_ILOCK_SHARED)
331                 mrunlock_shared(&ip->i_lock);
332 
333         trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
334 }
335 
336 /*
337  * give up write locks.  the i/o lock cannot be held nested
338  * if it is being demoted.
339  */
340 void
341 xfs_ilock_demote(
342         xfs_inode_t             *ip,
343         uint                    lock_flags)
344 {
345         ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL));
346         ASSERT((lock_flags &
347                 ~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
348 
349         if (lock_flags & XFS_ILOCK_EXCL)
350                 mrdemote(&ip->i_lock);
351         if (lock_flags & XFS_MMAPLOCK_EXCL)
352                 mrdemote(&ip->i_mmaplock);
353         if (lock_flags & XFS_IOLOCK_EXCL)
354                 downgrade_write(&VFS_I(ip)->i_rwsem);
355 
356         trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
357 }
358 
359 #if defined(DEBUG) || defined(XFS_WARN)
360 int
361 xfs_isilocked(
362         xfs_inode_t             *ip,
363         uint                    lock_flags)
364 {
365         if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
366                 if (!(lock_flags & XFS_ILOCK_SHARED))
367                         return !!ip->i_lock.mr_writer;
368                 return rwsem_is_locked(&ip->i_lock.mr_lock);
369         }
370 
371         if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) {
372                 if (!(lock_flags & XFS_MMAPLOCK_SHARED))
373                         return !!ip->i_mmaplock.mr_writer;
374                 return rwsem_is_locked(&ip->i_mmaplock.mr_lock);
375         }
376 
377         if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
378                 if (!(lock_flags & XFS_IOLOCK_SHARED))
379                         return !debug_locks ||
380                                 lockdep_is_held_type(&VFS_I(ip)->i_rwsem, 0);
381                 return rwsem_is_locked(&VFS_I(ip)->i_rwsem);
382         }
383 
384         ASSERT(0);
385         return 0;
386 }
387 #endif
388 
389 /*
390  * xfs_lockdep_subclass_ok() is only used in an ASSERT, so is only called when
391  * DEBUG or XFS_WARN is set. And MAX_LOCKDEP_SUBCLASSES is then only defined
392  * when CONFIG_LOCKDEP is set. Hence the complex define below to avoid build
393  * errors and warnings.
394  */
395 #if (defined(DEBUG) || defined(XFS_WARN)) && defined(CONFIG_LOCKDEP)
396 static bool
397 xfs_lockdep_subclass_ok(
398         int subclass)
399 {
400         return subclass < MAX_LOCKDEP_SUBCLASSES;
401 }
402 #else
403 #define xfs_lockdep_subclass_ok(subclass)       (true)
404 #endif
405 
406 /*
407  * Bump the subclass so xfs_lock_inodes() acquires each lock with a different
408  * value. This can be called for any type of inode lock combination, including
409  * parent locking. Care must be taken to ensure we don't overrun the subclass
410  * storage fields in the class mask we build.
411  */
412 static inline int
413 xfs_lock_inumorder(int lock_mode, int subclass)
414 {
415         int     class = 0;
416 
417         ASSERT(!(lock_mode & (XFS_ILOCK_PARENT | XFS_ILOCK_RTBITMAP |
418                               XFS_ILOCK_RTSUM)));
419         ASSERT(xfs_lockdep_subclass_ok(subclass));
420 
421         if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) {
422                 ASSERT(subclass <= XFS_IOLOCK_MAX_SUBCLASS);
423                 class += subclass << XFS_IOLOCK_SHIFT;
424         }
425 
426         if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) {
427                 ASSERT(subclass <= XFS_MMAPLOCK_MAX_SUBCLASS);
428                 class += subclass << XFS_MMAPLOCK_SHIFT;
429         }
430 
431         if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) {
432                 ASSERT(subclass <= XFS_ILOCK_MAX_SUBCLASS);
433                 class += subclass << XFS_ILOCK_SHIFT;
434         }
435 
436         return (lock_mode & ~XFS_LOCK_SUBCLASS_MASK) | class;
437 }
438 
439 /*
440  * The following routine will lock n inodes in exclusive mode.  We assume the
441  * caller calls us with the inodes in i_ino order.
442  *
443  * We need to detect deadlock where an inode that we lock is in the AIL and we
444  * start waiting for another inode that is locked by a thread in a long running
445  * transaction (such as truncate). This can result in deadlock since the long
446  * running trans might need to wait for the inode we just locked in order to
447  * push the tail and free space in the log.
448  *
449  * xfs_lock_inodes() can only be used to lock one type of lock at a time -
450  * the iolock, the mmaplock or the ilock, but not more than one at a time. If we
451  * lock more than one at a time, lockdep will report false positives saying we
452  * have violated locking orders.
453  */
454 static void
455 xfs_lock_inodes(
456         xfs_inode_t     **ips,
457         int             inodes,
458         uint            lock_mode)
459 {
460         int             attempts = 0, i, j, try_lock;
461         xfs_log_item_t  *lp;
462 
463         /*
464          * Currently supports between 2 and 5 inodes with exclusive locking.  We
465          * support an arbitrary depth of locking here, but absolute limits on
466          * inodes depend on the the type of locking and the limits placed by
467          * lockdep annotations in xfs_lock_inumorder.  These are all checked by
468          * the asserts.
469          */
470         ASSERT(ips && inodes >= 2 && inodes <= 5);
471         ASSERT(lock_mode & (XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL |
472                             XFS_ILOCK_EXCL));
473         ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED | XFS_MMAPLOCK_SHARED |
474                               XFS_ILOCK_SHARED)));
475         ASSERT(!(lock_mode & XFS_MMAPLOCK_EXCL) ||
476                 inodes <= XFS_MMAPLOCK_MAX_SUBCLASS + 1);
477         ASSERT(!(lock_mode & XFS_ILOCK_EXCL) ||
478                 inodes <= XFS_ILOCK_MAX_SUBCLASS + 1);
479 
480         if (lock_mode & XFS_IOLOCK_EXCL) {
481                 ASSERT(!(lock_mode & (XFS_MMAPLOCK_EXCL | XFS_ILOCK_EXCL)));
482         } else if (lock_mode & XFS_MMAPLOCK_EXCL)
483                 ASSERT(!(lock_mode & XFS_ILOCK_EXCL));
484 
485         try_lock = 0;
486         i = 0;
487 again:
488         for (; i < inodes; i++) {
489                 ASSERT(ips[i]);
490 
491                 if (i && (ips[i] == ips[i - 1]))        /* Already locked */
492                         continue;
493 
494                 /*
495                  * If try_lock is not set yet, make sure all locked inodes are
496                  * not in the AIL.  If any are, set try_lock to be used later.
497                  */
498                 if (!try_lock) {
499                         for (j = (i - 1); j >= 0 && !try_lock; j--) {
500                                 lp = (xfs_log_item_t *)ips[j]->i_itemp;
501                                 if (lp && (lp->li_flags & XFS_LI_IN_AIL))
502                                         try_lock++;
503                         }
504                 }
505 
506                 /*
507                  * If any of the previous locks we have locked is in the AIL,
508                  * we must TRY to get the second and subsequent locks. If
509                  * we can't get any, we must release all we have
510                  * and try again.
511                  */
512                 if (!try_lock) {
513                         xfs_ilock(ips[i], xfs_lock_inumorder(lock_mode, i));
514                         continue;
515                 }
516 
517                 /* try_lock means we have an inode locked that is in the AIL. */
518                 ASSERT(i != 0);
519                 if (xfs_ilock_nowait(ips[i], xfs_lock_inumorder(lock_mode, i)))
520                         continue;
521 
522                 /*
523                  * Unlock all previous guys and try again.  xfs_iunlock will try
524                  * to push the tail if the inode is in the AIL.
525                  */
526                 attempts++;
527                 for (j = i - 1; j >= 0; j--) {
528                         /*
529                          * Check to see if we've already unlocked this one.  Not
530                          * the first one going back, and the inode ptr is the
531                          * same.
532                          */
533                         if (j != (i - 1) && ips[j] == ips[j + 1])
534                                 continue;
535 
536                         xfs_iunlock(ips[j], lock_mode);
537                 }
538 
539                 if ((attempts % 5) == 0) {
540                         delay(1); /* Don't just spin the CPU */
541                 }
542                 i = 0;
543                 try_lock = 0;
544                 goto again;
545         }
546 }
547 
548 /*
549  * xfs_lock_two_inodes() can only be used to lock one type of lock at a time -
550  * the mmaplock or the ilock, but not more than one type at a time. If we lock
551  * more than one at a time, lockdep will report false positives saying we have
552  * violated locking orders.  The iolock must be double-locked separately since
553  * we use i_rwsem for that.  We now support taking one lock EXCL and the other
554  * SHARED.
555  */
556 void
557 xfs_lock_two_inodes(
558         struct xfs_inode        *ip0,
559         uint                    ip0_mode,
560         struct xfs_inode        *ip1,
561         uint                    ip1_mode)
562 {
563         struct xfs_inode        *temp;
564         uint                    mode_temp;
565         int                     attempts = 0;
566         xfs_log_item_t          *lp;
567 
568         ASSERT(hweight32(ip0_mode) == 1);
569         ASSERT(hweight32(ip1_mode) == 1);
570         ASSERT(!(ip0_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
571         ASSERT(!(ip1_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
572         ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
573                !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
574         ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
575                !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
576         ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
577                !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
578         ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
579                !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
580 
581         ASSERT(ip0->i_ino != ip1->i_ino);
582 
583         if (ip0->i_ino > ip1->i_ino) {
584                 temp = ip0;
585                 ip0 = ip1;
586                 ip1 = temp;
587                 mode_temp = ip0_mode;
588                 ip0_mode = ip1_mode;
589                 ip1_mode = mode_temp;
590         }
591 
592  again:
593         xfs_ilock(ip0, xfs_lock_inumorder(ip0_mode, 0));
594 
595         /*
596          * If the first lock we have locked is in the AIL, we must TRY to get
597          * the second lock. If we can't get it, we must release the first one
598          * and try again.
599          */
600         lp = (xfs_log_item_t *)ip0->i_itemp;
601         if (lp && (lp->li_flags & XFS_LI_IN_AIL)) {
602                 if (!xfs_ilock_nowait(ip1, xfs_lock_inumorder(ip1_mode, 1))) {
603                         xfs_iunlock(ip0, ip0_mode);
604                         if ((++attempts % 5) == 0)
605                                 delay(1); /* Don't just spin the CPU */
606                         goto again;
607                 }
608         } else {
609                 xfs_ilock(ip1, xfs_lock_inumorder(ip1_mode, 1));
610         }
611 }
612 
613 void
614 __xfs_iflock(
615         struct xfs_inode        *ip)
616 {
617         wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IFLOCK_BIT);
618         DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IFLOCK_BIT);
619 
620         do {
621                 prepare_to_wait_exclusive(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
622                 if (xfs_isiflocked(ip))
623                         io_schedule();
624         } while (!xfs_iflock_nowait(ip));
625 
626         finish_wait(wq, &wait.wq_entry);
627 }
628 
629 STATIC uint
630 _xfs_dic2xflags(
631         uint16_t                di_flags,
632         uint64_t                di_flags2,
633         bool                    has_attr)
634 {
635         uint                    flags = 0;
636 
637         if (di_flags & XFS_DIFLAG_ANY) {
638                 if (di_flags & XFS_DIFLAG_REALTIME)
639                         flags |= FS_XFLAG_REALTIME;
640                 if (di_flags & XFS_DIFLAG_PREALLOC)
641                         flags |= FS_XFLAG_PREALLOC;
642                 if (di_flags & XFS_DIFLAG_IMMUTABLE)
643                         flags |= FS_XFLAG_IMMUTABLE;
644                 if (di_flags & XFS_DIFLAG_APPEND)
645                         flags |= FS_XFLAG_APPEND;
646                 if (di_flags & XFS_DIFLAG_SYNC)
647                         flags |= FS_XFLAG_SYNC;
648                 if (di_flags & XFS_DIFLAG_NOATIME)
649                         flags |= FS_XFLAG_NOATIME;
650                 if (di_flags & XFS_DIFLAG_NODUMP)
651                         flags |= FS_XFLAG_NODUMP;
652                 if (di_flags & XFS_DIFLAG_RTINHERIT)
653                         flags |= FS_XFLAG_RTINHERIT;
654                 if (di_flags & XFS_DIFLAG_PROJINHERIT)
655                         flags |= FS_XFLAG_PROJINHERIT;
656                 if (di_flags & XFS_DIFLAG_NOSYMLINKS)
657                         flags |= FS_XFLAG_NOSYMLINKS;
658                 if (di_flags & XFS_DIFLAG_EXTSIZE)
659                         flags |= FS_XFLAG_EXTSIZE;
660                 if (di_flags & XFS_DIFLAG_EXTSZINHERIT)
661                         flags |= FS_XFLAG_EXTSZINHERIT;
662                 if (di_flags & XFS_DIFLAG_NODEFRAG)
663                         flags |= FS_XFLAG_NODEFRAG;
664                 if (di_flags & XFS_DIFLAG_FILESTREAM)
665                         flags |= FS_XFLAG_FILESTREAM;
666         }
667 
668         if (di_flags2 & XFS_DIFLAG2_ANY) {
669                 if (di_flags2 & XFS_DIFLAG2_DAX)
670                         flags |= FS_XFLAG_DAX;
671                 if (di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
672                         flags |= FS_XFLAG_COWEXTSIZE;
673         }
674 
675         if (has_attr)
676                 flags |= FS_XFLAG_HASATTR;
677 
678         return flags;
679 }
680 
681 uint
682 xfs_ip2xflags(
683         struct xfs_inode        *ip)
684 {
685         struct xfs_icdinode     *dic = &ip->i_d;
686 
687         return _xfs_dic2xflags(dic->di_flags, dic->di_flags2, XFS_IFORK_Q(ip));
688 }
689 
690 /*
691  * Lookups up an inode from "name". If ci_name is not NULL, then a CI match
692  * is allowed, otherwise it has to be an exact match. If a CI match is found,
693  * ci_name->name will point to a the actual name (caller must free) or
694  * will be set to NULL if an exact match is found.
695  */
696 int
697 xfs_lookup(
698         xfs_inode_t             *dp,
699         struct xfs_name         *name,
700         xfs_inode_t             **ipp,
701         struct xfs_name         *ci_name)
702 {
703         xfs_ino_t               inum;
704         int                     error;
705 
706         trace_xfs_lookup(dp, name);
707 
708         if (XFS_FORCED_SHUTDOWN(dp->i_mount))
709                 return -EIO;
710 
711         error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
712         if (error)
713                 goto out_unlock;
714 
715         error = xfs_iget(dp->i_mount, NULL, inum, 0, 0, ipp);
716         if (error)
717                 goto out_free_name;
718 
719         return 0;
720 
721 out_free_name:
722         if (ci_name)
723                 kmem_free(ci_name->name);
724 out_unlock:
725         *ipp = NULL;
726         return error;
727 }
728 
729 /*
730  * Allocate an inode on disk and return a copy of its in-core version.
731  * The in-core inode is locked exclusively.  Set mode, nlink, and rdev
732  * appropriately within the inode.  The uid and gid for the inode are
733  * set according to the contents of the given cred structure.
734  *
735  * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
736  * has a free inode available, call xfs_iget() to obtain the in-core
737  * version of the allocated inode.  Finally, fill in the inode and
738  * log its initial contents.  In this case, ialloc_context would be
739  * set to NULL.
740  *
741  * If xfs_dialloc() does not have an available inode, it will replenish
742  * its supply by doing an allocation. Since we can only do one
743  * allocation within a transaction without deadlocks, we must commit
744  * the current transaction before returning the inode itself.
745  * In this case, therefore, we will set ialloc_context and return.
746  * The caller should then commit the current transaction, start a new
747  * transaction, and call xfs_ialloc() again to actually get the inode.
748  *
749  * To ensure that some other process does not grab the inode that
750  * was allocated during the first call to xfs_ialloc(), this routine
751  * also returns the [locked] bp pointing to the head of the freelist
752  * as ialloc_context.  The caller should hold this buffer across
753  * the commit and pass it back into this routine on the second call.
754  *
755  * If we are allocating quota inodes, we do not have a parent inode
756  * to attach to or associate with (i.e. pip == NULL) because they
757  * are not linked into the directory structure - they are attached
758  * directly to the superblock - and so have no parent.
759  */
760 static int
761 xfs_ialloc(
762         xfs_trans_t     *tp,
763         xfs_inode_t     *pip,
764         umode_t         mode,
765         xfs_nlink_t     nlink,
766         dev_t           rdev,
767         prid_t          prid,
768         xfs_buf_t       **ialloc_context,
769         xfs_inode_t     **ipp)
770 {
771         struct xfs_mount *mp = tp->t_mountp;
772         xfs_ino_t       ino;
773         xfs_inode_t     *ip;
774         uint            flags;
775         int             error;
776         struct timespec tv;
777         struct inode    *inode;
778 
779         /*
780          * Call the space management code to pick
781          * the on-disk inode to be allocated.
782          */
783         error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode,
784                             ialloc_context, &ino);
785         if (error)
786                 return error;
787         if (*ialloc_context || ino == NULLFSINO) {
788                 *ipp = NULL;
789                 return 0;
790         }
791         ASSERT(*ialloc_context == NULL);
792 
793         /*
794          * Get the in-core inode with the lock held exclusively.
795          * This is because we're setting fields here we need
796          * to prevent others from looking at until we're done.
797          */
798         error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE,
799                          XFS_ILOCK_EXCL, &ip);
800         if (error)
801                 return error;
802         ASSERT(ip != NULL);
803         inode = VFS_I(ip);
804 
805         /*
806          * We always convert v1 inodes to v2 now - we only support filesystems
807          * with >= v2 inode capability, so there is no reason for ever leaving
808          * an inode in v1 format.
809          */
810         if (ip->i_d.di_version == 1)
811                 ip->i_d.di_version = 2;
812 
813         inode->i_mode = mode;
814         set_nlink(inode, nlink);
815         ip->i_d.di_uid = xfs_kuid_to_uid(current_fsuid());
816         ip->i_d.di_gid = xfs_kgid_to_gid(current_fsgid());
817         inode->i_rdev = rdev;
818         xfs_set_projid(ip, prid);
819 
820         if (pip && XFS_INHERIT_GID(pip)) {
821                 ip->i_d.di_gid = pip->i_d.di_gid;
822                 if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode))
823                         inode->i_mode |= S_ISGID;
824         }
825 
826         /*
827          * If the group ID of the new file does not match the effective group
828          * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
829          * (and only if the irix_sgid_inherit compatibility variable is set).
830          */
831         if ((irix_sgid_inherit) &&
832             (inode->i_mode & S_ISGID) &&
833             (!in_group_p(xfs_gid_to_kgid(ip->i_d.di_gid))))
834                 inode->i_mode &= ~S_ISGID;
835 
836         ip->i_d.di_size = 0;
837         ip->i_d.di_nextents = 0;
838         ASSERT(ip->i_d.di_nblocks == 0);
839 
840         tv = current_time(inode);
841         inode->i_mtime = tv;
842         inode->i_atime = tv;
843         inode->i_ctime = tv;
844 
845         ip->i_d.di_extsize = 0;
846         ip->i_d.di_dmevmask = 0;
847         ip->i_d.di_dmstate = 0;
848         ip->i_d.di_flags = 0;
849 
850         if (ip->i_d.di_version == 3) {
851                 inode_set_iversion(inode, 1);
852                 ip->i_d.di_flags2 = 0;
853                 ip->i_d.di_cowextsize = 0;
854                 ip->i_d.di_crtime.t_sec = (int32_t)tv.tv_sec;
855                 ip->i_d.di_crtime.t_nsec = (int32_t)tv.tv_nsec;
856         }
857 
858 
859         flags = XFS_ILOG_CORE;
860         switch (mode & S_IFMT) {
861         case S_IFIFO:
862         case S_IFCHR:
863         case S_IFBLK:
864         case S_IFSOCK:
865                 ip->i_d.di_format = XFS_DINODE_FMT_DEV;
866                 ip->i_df.if_flags = 0;
867                 flags |= XFS_ILOG_DEV;
868                 break;
869         case S_IFREG:
870         case S_IFDIR:
871                 if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
872                         uint            di_flags = 0;
873 
874                         if (S_ISDIR(mode)) {
875                                 if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
876                                         di_flags |= XFS_DIFLAG_RTINHERIT;
877                                 if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
878                                         di_flags |= XFS_DIFLAG_EXTSZINHERIT;
879                                         ip->i_d.di_extsize = pip->i_d.di_extsize;
880                                 }
881                                 if (pip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
882                                         di_flags |= XFS_DIFLAG_PROJINHERIT;
883                         } else if (S_ISREG(mode)) {
884                                 if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
885                                         di_flags |= XFS_DIFLAG_REALTIME;
886                                 if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
887                                         di_flags |= XFS_DIFLAG_EXTSIZE;
888                                         ip->i_d.di_extsize = pip->i_d.di_extsize;
889                                 }
890                         }
891                         if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
892                             xfs_inherit_noatime)
893                                 di_flags |= XFS_DIFLAG_NOATIME;
894                         if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
895                             xfs_inherit_nodump)
896                                 di_flags |= XFS_DIFLAG_NODUMP;
897                         if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
898                             xfs_inherit_sync)
899                                 di_flags |= XFS_DIFLAG_SYNC;
900                         if ((pip->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) &&
901                             xfs_inherit_nosymlinks)
902                                 di_flags |= XFS_DIFLAG_NOSYMLINKS;
903                         if ((pip->i_d.di_flags & XFS_DIFLAG_NODEFRAG) &&
904                             xfs_inherit_nodefrag)
905                                 di_flags |= XFS_DIFLAG_NODEFRAG;
906                         if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
907                                 di_flags |= XFS_DIFLAG_FILESTREAM;
908 
909                         ip->i_d.di_flags |= di_flags;
910                 }
911                 if (pip &&
912                     (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY) &&
913                     pip->i_d.di_version == 3 &&
914                     ip->i_d.di_version == 3) {
915                         uint64_t        di_flags2 = 0;
916 
917                         if (pip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) {
918                                 di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
919                                 ip->i_d.di_cowextsize = pip->i_d.di_cowextsize;
920                         }
921                         if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
922                                 di_flags2 |= XFS_DIFLAG2_DAX;
923 
924                         ip->i_d.di_flags2 |= di_flags2;
925                 }
926                 /* FALLTHROUGH */
927         case S_IFLNK:
928                 ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
929                 ip->i_df.if_flags = XFS_IFEXTENTS;
930                 ip->i_df.if_bytes = ip->i_df.if_real_bytes = 0;
931                 ip->i_df.if_u1.if_root = NULL;
932                 break;
933         default:
934                 ASSERT(0);
935         }
936         /*
937          * Attribute fork settings for new inode.
938          */
939         ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
940         ip->i_d.di_anextents = 0;
941 
942         /*
943          * Log the new values stuffed into the inode.
944          */
945         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
946         xfs_trans_log_inode(tp, ip, flags);
947 
948         /* now that we have an i_mode we can setup the inode structure */
949         xfs_setup_inode(ip);
950 
951         *ipp = ip;
952         return 0;
953 }
954 
955 /*
956  * Allocates a new inode from disk and return a pointer to the
957  * incore copy. This routine will internally commit the current
958  * transaction and allocate a new one if the Space Manager needed
959  * to do an allocation to replenish the inode free-list.
960  *
961  * This routine is designed to be called from xfs_create and
962  * xfs_create_dir.
963  *
964  */
965 int
966 xfs_dir_ialloc(
967         xfs_trans_t     **tpp,          /* input: current transaction;
968                                            output: may be a new transaction. */
969         xfs_inode_t     *dp,            /* directory within whose allocate
970                                            the inode. */
971         umode_t         mode,
972         xfs_nlink_t     nlink,
973         dev_t           rdev,
974         prid_t          prid,           /* project id */
975         xfs_inode_t     **ipp)          /* pointer to inode; it will be
976                                            locked. */
977 {
978         xfs_trans_t     *tp;
979         xfs_inode_t     *ip;
980         xfs_buf_t       *ialloc_context = NULL;
981         int             code;
982         void            *dqinfo;
983         uint            tflags;
984 
985         tp = *tpp;
986         ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
987 
988         /*
989          * xfs_ialloc will return a pointer to an incore inode if
990          * the Space Manager has an available inode on the free
991          * list. Otherwise, it will do an allocation and replenish
992          * the freelist.  Since we can only do one allocation per
993          * transaction without deadlocks, we will need to commit the
994          * current transaction and start a new one.  We will then
995          * need to call xfs_ialloc again to get the inode.
996          *
997          * If xfs_ialloc did an allocation to replenish the freelist,
998          * it returns the bp containing the head of the freelist as
999          * ialloc_context. We will hold a lock on it across the
1000          * transaction commit so that no other process can steal
1001          * the inode(s) that we've just allocated.
1002          */
1003         code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, &ialloc_context,
1004                         &ip);
1005 
1006         /*
1007          * Return an error if we were unable to allocate a new inode.
1008          * This should only happen if we run out of space on disk or
1009          * encounter a disk error.
1010          */
1011         if (code) {
1012                 *ipp = NULL;
1013                 return code;
1014         }
1015         if (!ialloc_context && !ip) {
1016                 *ipp = NULL;
1017                 return -ENOSPC;
1018         }
1019 
1020         /*
1021          * If the AGI buffer is non-NULL, then we were unable to get an
1022          * inode in one operation.  We need to commit the current
1023          * transaction and call xfs_ialloc() again.  It is guaranteed
1024          * to succeed the second time.
1025          */
1026         if (ialloc_context) {
1027                 /*
1028                  * Normally, xfs_trans_commit releases all the locks.
1029                  * We call bhold to hang on to the ialloc_context across
1030                  * the commit.  Holding this buffer prevents any other
1031                  * processes from doing any allocations in this
1032                  * allocation group.
1033                  */
1034                 xfs_trans_bhold(tp, ialloc_context);
1035 
1036                 /*
1037                  * We want the quota changes to be associated with the next
1038                  * transaction, NOT this one. So, detach the dqinfo from this
1039                  * and attach it to the next transaction.
1040                  */
1041                 dqinfo = NULL;
1042                 tflags = 0;
1043                 if (tp->t_dqinfo) {
1044                         dqinfo = (void *)tp->t_dqinfo;
1045                         tp->t_dqinfo = NULL;
1046                         tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
1047                         tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
1048                 }
1049 
1050                 code = xfs_trans_roll(&tp);
1051 
1052                 /*
1053                  * Re-attach the quota info that we detached from prev trx.
1054                  */
1055                 if (dqinfo) {
1056                         tp->t_dqinfo = dqinfo;
1057                         tp->t_flags |= tflags;
1058                 }
1059 
1060                 if (code) {
1061                         xfs_buf_relse(ialloc_context);
1062                         *tpp = tp;
1063                         *ipp = NULL;
1064                         return code;
1065                 }
1066                 xfs_trans_bjoin(tp, ialloc_context);
1067 
1068                 /*
1069                  * Call ialloc again. Since we've locked out all
1070                  * other allocations in this allocation group,
1071                  * this call should always succeed.
1072                  */
1073                 code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
1074                                   &ialloc_context, &ip);
1075 
1076                 /*
1077                  * If we get an error at this point, return to the caller
1078                  * so that the current transaction can be aborted.
1079                  */
1080                 if (code) {
1081                         *tpp = tp;
1082                         *ipp = NULL;
1083                         return code;
1084                 }
1085                 ASSERT(!ialloc_context && ip);
1086 
1087         }
1088 
1089         *ipp = ip;
1090         *tpp = tp;
1091 
1092         return 0;
1093 }
1094 
1095 /*
1096  * Decrement the link count on an inode & log the change.  If this causes the
1097  * link count to go to zero, move the inode to AGI unlinked list so that it can
1098  * be freed when the last active reference goes away via xfs_inactive().
1099  */
1100 static int                      /* error */
1101 xfs_droplink(
1102         xfs_trans_t *tp,
1103         xfs_inode_t *ip)
1104 {
1105         xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1106 
1107         drop_nlink(VFS_I(ip));
1108         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1109 
1110         if (VFS_I(ip)->i_nlink)
1111                 return 0;
1112 
1113         return xfs_iunlink(tp, ip);
1114 }
1115 
1116 /*
1117  * Increment the link count on an inode & log the change.
1118  */
1119 static int
1120 xfs_bumplink(
1121         xfs_trans_t *tp,
1122         xfs_inode_t *ip)
1123 {
1124         xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
1125 
1126         ASSERT(ip->i_d.di_version > 1);
1127         inc_nlink(VFS_I(ip));
1128         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1129         return 0;
1130 }
1131 
1132 int
1133 xfs_create(
1134         xfs_inode_t             *dp,
1135         struct xfs_name         *name,
1136         umode_t                 mode,
1137         dev_t                   rdev,
1138         xfs_inode_t             **ipp)
1139 {
1140         int                     is_dir = S_ISDIR(mode);
1141         struct xfs_mount        *mp = dp->i_mount;
1142         struct xfs_inode        *ip = NULL;
1143         struct xfs_trans        *tp = NULL;
1144         int                     error;
1145         struct xfs_defer_ops    dfops;
1146         xfs_fsblock_t           first_block;
1147         bool                    unlock_dp_on_error = false;
1148         prid_t                  prid;
1149         struct xfs_dquot        *udqp = NULL;
1150         struct xfs_dquot        *gdqp = NULL;
1151         struct xfs_dquot        *pdqp = NULL;
1152         struct xfs_trans_res    *tres;
1153         uint                    resblks;
1154 
1155         trace_xfs_create(dp, name);
1156 
1157         if (XFS_FORCED_SHUTDOWN(mp))
1158                 return -EIO;
1159 
1160         prid = xfs_get_initial_prid(dp);
1161 
1162         /*
1163          * Make sure that we have allocated dquot(s) on disk.
1164          */
1165         error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1166                                         xfs_kgid_to_gid(current_fsgid()), prid,
1167                                         XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1168                                         &udqp, &gdqp, &pdqp);
1169         if (error)
1170                 return error;
1171 
1172         if (is_dir) {
1173                 resblks = XFS_MKDIR_SPACE_RES(mp, name->len);
1174                 tres = &M_RES(mp)->tr_mkdir;
1175         } else {
1176                 resblks = XFS_CREATE_SPACE_RES(mp, name->len);
1177                 tres = &M_RES(mp)->tr_create;
1178         }
1179 
1180         /*
1181          * Initially assume that the file does not exist and
1182          * reserve the resources for that case.  If that is not
1183          * the case we'll drop the one we have and get a more
1184          * appropriate transaction later.
1185          */
1186         error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1187         if (error == -ENOSPC) {
1188                 /* flush outstanding delalloc blocks and retry */
1189                 xfs_flush_inodes(mp);
1190                 error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1191         }
1192         if (error)
1193                 goto out_release_inode;
1194 
1195         xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
1196         unlock_dp_on_error = true;
1197 
1198         xfs_defer_init(&dfops, &first_block);
1199 
1200         /*
1201          * Reserve disk quota and the inode.
1202          */
1203         error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1204                                                 pdqp, resblks, 1, 0);
1205         if (error)
1206                 goto out_trans_cancel;
1207 
1208         /*
1209          * A newly created regular or special file just has one directory
1210          * entry pointing to them, but a directory also the "." entry
1211          * pointing to itself.
1212          */
1213         error = xfs_dir_ialloc(&tp, dp, mode, is_dir ? 2 : 1, rdev, prid, &ip);
1214         if (error)
1215                 goto out_trans_cancel;
1216 
1217         /*
1218          * Now we join the directory inode to the transaction.  We do not do it
1219          * earlier because xfs_dir_ialloc might commit the previous transaction
1220          * (and release all the locks).  An error from here on will result in
1221          * the transaction cancel unlocking dp so don't do it explicitly in the
1222          * error path.
1223          */
1224         xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
1225         unlock_dp_on_error = false;
1226 
1227         error = xfs_dir_createname(tp, dp, name, ip->i_ino,
1228                                         &first_block, &dfops, resblks ?
1229                                         resblks - XFS_IALLOC_SPACE_RES(mp) : 0);
1230         if (error) {
1231                 ASSERT(error != -ENOSPC);
1232                 goto out_trans_cancel;
1233         }
1234         xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1235         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1236 
1237         if (is_dir) {
1238                 error = xfs_dir_init(tp, ip, dp);
1239                 if (error)
1240                         goto out_bmap_cancel;
1241 
1242                 error = xfs_bumplink(tp, dp);
1243                 if (error)
1244                         goto out_bmap_cancel;
1245         }
1246 
1247         /*
1248          * If this is a synchronous mount, make sure that the
1249          * create transaction goes to disk before returning to
1250          * the user.
1251          */
1252         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1253                 xfs_trans_set_sync(tp);
1254 
1255         /*
1256          * Attach the dquot(s) to the inodes and modify them incore.
1257          * These ids of the inode couldn't have changed since the new
1258          * inode has been locked ever since it was created.
1259          */
1260         xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1261 
1262         error = xfs_defer_finish(&tp, &dfops);
1263         if (error)
1264                 goto out_bmap_cancel;
1265 
1266         error = xfs_trans_commit(tp);
1267         if (error)
1268                 goto out_release_inode;
1269 
1270         xfs_qm_dqrele(udqp);
1271         xfs_qm_dqrele(gdqp);
1272         xfs_qm_dqrele(pdqp);
1273 
1274         *ipp = ip;
1275         return 0;
1276 
1277  out_bmap_cancel:
1278         xfs_defer_cancel(&dfops);
1279  out_trans_cancel:
1280         xfs_trans_cancel(tp);
1281  out_release_inode:
1282         /*
1283          * Wait until after the current transaction is aborted to finish the
1284          * setup of the inode and release the inode.  This prevents recursive
1285          * transactions and deadlocks from xfs_inactive.
1286          */
1287         if (ip) {
1288                 xfs_finish_inode_setup(ip);
1289                 IRELE(ip);
1290         }
1291 
1292         xfs_qm_dqrele(udqp);
1293         xfs_qm_dqrele(gdqp);
1294         xfs_qm_dqrele(pdqp);
1295 
1296         if (unlock_dp_on_error)
1297                 xfs_iunlock(dp, XFS_ILOCK_EXCL);
1298         return error;
1299 }
1300 
1301 int
1302 xfs_create_tmpfile(
1303         struct xfs_inode        *dp,
1304         umode_t                 mode,
1305         struct xfs_inode        **ipp)
1306 {
1307         struct xfs_mount        *mp = dp->i_mount;
1308         struct xfs_inode        *ip = NULL;
1309         struct xfs_trans        *tp = NULL;
1310         int                     error;
1311         prid_t                  prid;
1312         struct xfs_dquot        *udqp = NULL;
1313         struct xfs_dquot        *gdqp = NULL;
1314         struct xfs_dquot        *pdqp = NULL;
1315         struct xfs_trans_res    *tres;
1316         uint                    resblks;
1317 
1318         if (XFS_FORCED_SHUTDOWN(mp))
1319                 return -EIO;
1320 
1321         prid = xfs_get_initial_prid(dp);
1322 
1323         /*
1324          * Make sure that we have allocated dquot(s) on disk.
1325          */
1326         error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()),
1327                                 xfs_kgid_to_gid(current_fsgid()), prid,
1328                                 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
1329                                 &udqp, &gdqp, &pdqp);
1330         if (error)
1331                 return error;
1332 
1333         resblks = XFS_IALLOC_SPACE_RES(mp);
1334         tres = &M_RES(mp)->tr_create_tmpfile;
1335 
1336         error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
1337         if (error)
1338                 goto out_release_inode;
1339 
1340         error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
1341                                                 pdqp, resblks, 1, 0);
1342         if (error)
1343                 goto out_trans_cancel;
1344 
1345         error = xfs_dir_ialloc(&tp, dp, mode, 1, 0, prid, &ip);
1346         if (error)
1347                 goto out_trans_cancel;
1348 
1349         if (mp->m_flags & XFS_MOUNT_WSYNC)
1350                 xfs_trans_set_sync(tp);
1351 
1352         /*
1353          * Attach the dquot(s) to the inodes and modify them incore.
1354          * These ids of the inode couldn't have changed since the new
1355          * inode has been locked ever since it was created.
1356          */
1357         xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
1358 
1359         error = xfs_iunlink(tp, ip);
1360         if (error)
1361                 goto out_trans_cancel;
1362 
1363         error = xfs_trans_commit(tp);
1364         if (error)
1365                 goto out_release_inode;
1366 
1367         xfs_qm_dqrele(udqp);
1368         xfs_qm_dqrele(gdqp);
1369         xfs_qm_dqrele(pdqp);
1370 
1371         *ipp = ip;
1372         return 0;
1373 
1374  out_trans_cancel:
1375         xfs_trans_cancel(tp);
1376  out_release_inode:
1377         /*
1378          * Wait until after the current transaction is aborted to finish the
1379          * setup of the inode and release the inode.  This prevents recursive
1380          * transactions and deadlocks from xfs_inactive.
1381          */
1382         if (ip) {
1383                 xfs_finish_inode_setup(ip);
1384                 IRELE(ip);
1385         }
1386 
1387         xfs_qm_dqrele(udqp);
1388         xfs_qm_dqrele(gdqp);
1389         xfs_qm_dqrele(pdqp);
1390 
1391         return error;
1392 }
1393 
1394 int
1395 xfs_link(
1396         xfs_inode_t             *tdp,
1397         xfs_inode_t             *sip,
1398         struct xfs_name         *target_name)
1399 {
1400         xfs_mount_t             *mp = tdp->i_mount;
1401         xfs_trans_t             *tp;
1402         int                     error;
1403         struct xfs_defer_ops    dfops;
1404         xfs_fsblock_t           first_block;
1405         int                     resblks;
1406 
1407         trace_xfs_link(tdp, target_name);
1408 
1409         ASSERT(!S_ISDIR(VFS_I(sip)->i_mode));
1410 
1411         if (XFS_FORCED_SHUTDOWN(mp))
1412                 return -EIO;
1413 
1414         error = xfs_qm_dqattach(sip, 0);
1415         if (error)
1416                 goto std_return;
1417 
1418         error = xfs_qm_dqattach(tdp, 0);
1419         if (error)
1420                 goto std_return;
1421 
1422         resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
1423         error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, resblks, 0, 0, &tp);
1424         if (error == -ENOSPC) {
1425                 resblks = 0;
1426                 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_link, 0, 0, 0, &tp);
1427         }
1428         if (error)
1429                 goto std_return;
1430 
1431         xfs_lock_two_inodes(sip, XFS_ILOCK_EXCL, tdp, XFS_ILOCK_EXCL);
1432 
1433         xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
1434         xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
1435 
1436         /*
1437          * If we are using project inheritance, we only allow hard link
1438          * creation in our tree when the project IDs are the same; else
1439          * the tree quota mechanism could be circumvented.
1440          */
1441         if (unlikely((tdp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
1442                      (xfs_get_projid(tdp) != xfs_get_projid(sip)))) {
1443                 error = -EXDEV;
1444                 goto error_return;
1445         }
1446 
1447         if (!resblks) {
1448                 error = xfs_dir_canenter(tp, tdp, target_name);
1449                 if (error)
1450                         goto error_return;
1451         }
1452 
1453         xfs_defer_init(&dfops, &first_block);
1454 
1455         /*
1456          * Handle initial link state of O_TMPFILE inode
1457          */
1458         if (VFS_I(sip)->i_nlink == 0) {
1459                 error = xfs_iunlink_remove(tp, sip);
1460                 if (error)
1461                         goto error_return;
1462         }
1463 
1464         error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
1465                                         &first_block, &dfops, resblks);
1466         if (error)
1467                 goto error_return;
1468         xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
1469         xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
1470 
1471         error = xfs_bumplink(tp, sip);
1472         if (error)
1473                 goto error_return;
1474 
1475         /*
1476          * If this is a synchronous mount, make sure that the
1477          * link transaction goes to disk before returning to
1478          * the user.
1479          */
1480         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
1481                 xfs_trans_set_sync(tp);
1482 
1483         error = xfs_defer_finish(&tp, &dfops);
1484         if (error) {
1485                 xfs_defer_cancel(&dfops);
1486                 goto error_return;
1487         }
1488 
1489         return xfs_trans_commit(tp);
1490 
1491  error_return:
1492         xfs_trans_cancel(tp);
1493  std_return:
1494         return error;
1495 }
1496 
1497 /* Clear the reflink flag and the cowblocks tag if possible. */
1498 static void
1499 xfs_itruncate_clear_reflink_flags(
1500         struct xfs_inode        *ip)
1501 {
1502         struct xfs_ifork        *dfork;
1503         struct xfs_ifork        *cfork;
1504 
1505         if (!xfs_is_reflink_inode(ip))
1506                 return;
1507         dfork = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
1508         cfork = XFS_IFORK_PTR(ip, XFS_COW_FORK);
1509         if (dfork->if_bytes == 0 && cfork->if_bytes == 0)
1510                 ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
1511         if (cfork->if_bytes == 0)
1512                 xfs_inode_clear_cowblocks_tag(ip);
1513 }
1514 
1515 /*
1516  * Free up the underlying blocks past new_size.  The new size must be smaller
1517  * than the current size.  This routine can be used both for the attribute and
1518  * data fork, and does not modify the inode size, which is left to the caller.
1519  *
1520  * The transaction passed to this routine must have made a permanent log
1521  * reservation of at least XFS_ITRUNCATE_LOG_RES.  This routine may commit the
1522  * given transaction and start new ones, so make sure everything involved in
1523  * the transaction is tidy before calling here.  Some transaction will be
1524  * returned to the caller to be committed.  The incoming transaction must
1525  * already include the inode, and both inode locks must be held exclusively.
1526  * The inode must also be "held" within the transaction.  On return the inode
1527  * will be "held" within the returned transaction.  This routine does NOT
1528  * require any disk space to be reserved for it within the transaction.
1529  *
1530  * If we get an error, we must return with the inode locked and linked into the
1531  * current transaction. This keeps things simple for the higher level code,
1532  * because it always knows that the inode is locked and held in the transaction
1533  * that returns to it whether errors occur or not.  We don't mark the inode
1534  * dirty on error so that transactions can be easily aborted if possible.
1535  */
1536 int
1537 xfs_itruncate_extents(
1538         struct xfs_trans        **tpp,
1539         struct xfs_inode        *ip,
1540         int                     whichfork,
1541         xfs_fsize_t             new_size)
1542 {
1543         struct xfs_mount        *mp = ip->i_mount;
1544         struct xfs_trans        *tp = *tpp;
1545         struct xfs_defer_ops    dfops;
1546         xfs_fsblock_t           first_block;
1547         xfs_fileoff_t           first_unmap_block;
1548         xfs_fileoff_t           last_block;
1549         xfs_filblks_t           unmap_len;
1550         int                     error = 0;
1551         int                     done = 0;
1552 
1553         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1554         ASSERT(!atomic_read(&VFS_I(ip)->i_count) ||
1555                xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1556         ASSERT(new_size <= XFS_ISIZE(ip));
1557         ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
1558         ASSERT(ip->i_itemp != NULL);
1559         ASSERT(ip->i_itemp->ili_lock_flags == 0);
1560         ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
1561 
1562         trace_xfs_itruncate_extents_start(ip, new_size);
1563 
1564         /*
1565          * Since it is possible for space to become allocated beyond
1566          * the end of the file (in a crash where the space is allocated
1567          * but the inode size is not yet updated), simply remove any
1568          * blocks which show up between the new EOF and the maximum
1569          * possible file size.  If the first block to be removed is
1570          * beyond the maximum file size (ie it is the same as last_block),
1571          * then there is nothing to do.
1572          */
1573         first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
1574         last_block = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
1575         if (first_unmap_block == last_block)
1576                 return 0;
1577 
1578         ASSERT(first_unmap_block < last_block);
1579         unmap_len = last_block - first_unmap_block + 1;
1580         while (!done) {
1581                 xfs_defer_init(&dfops, &first_block);
1582                 error = xfs_bunmapi(tp, ip,
1583                                     first_unmap_block, unmap_len,
1584                                     xfs_bmapi_aflag(whichfork),
1585                                     XFS_ITRUNC_MAX_EXTENTS,
1586                                     &first_block, &dfops,
1587                                     &done);
1588                 if (error)
1589                         goto out_bmap_cancel;
1590 
1591                 /*
1592                  * Duplicate the transaction that has the permanent
1593                  * reservation and commit the old transaction.
1594                  */
1595                 xfs_defer_ijoin(&dfops, ip);
1596                 error = xfs_defer_finish(&tp, &dfops);
1597                 if (error)
1598                         goto out_bmap_cancel;
1599 
1600                 error = xfs_trans_roll_inode(&tp, ip);
1601                 if (error)
1602                         goto out;
1603         }
1604 
1605         if (whichfork == XFS_DATA_FORK) {
1606                 /* Remove all pending CoW reservations. */
1607                 error = xfs_reflink_cancel_cow_blocks(ip, &tp,
1608                                 first_unmap_block, last_block, true);
1609                 if (error)
1610                         goto out;
1611 
1612                 xfs_itruncate_clear_reflink_flags(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         struct xfs_ifork        *cow_ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
1869         int                     error;
1870         int                     truncate = 0;
1871 
1872         /*
1873          * If the inode is already free, then there can be nothing
1874          * to clean up here.
1875          */
1876         if (VFS_I(ip)->i_mode == 0) {
1877                 ASSERT(ip->i_df.if_real_bytes == 0);
1878                 ASSERT(ip->i_df.if_broot_bytes == 0);
1879                 return;
1880         }
1881 
1882         mp = ip->i_mount;
1883         ASSERT(!xfs_iflags_test(ip, XFS_IRECOVERY));
1884 
1885         /* If this is a read-only mount, don't do this (would generate I/O) */
1886         if (mp->m_flags & XFS_MOUNT_RDONLY)
1887                 return;
1888 
1889         /* Try to clean out the cow blocks if there are any. */
1890         if (xfs_is_reflink_inode(ip) && cow_ifp->if_bytes > 0)
1891                 xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, true);
1892 
1893         if (VFS_I(ip)->i_nlink != 0) {
1894                 /*
1895                  * force is true because we are evicting an inode from the
1896                  * cache. Post-eof blocks must be freed, lest we end up with
1897                  * broken free space accounting.
1898                  *
1899                  * Note: don't bother with iolock here since lockdep complains
1900                  * about acquiring it in reclaim context. We have the only
1901                  * reference to the inode at this point anyways.
1902                  */
1903                 if (xfs_can_free_eofblocks(ip, true))
1904                         xfs_free_eofblocks(ip);
1905 
1906                 return;
1907         }
1908 
1909         if (S_ISREG(VFS_I(ip)->i_mode) &&
1910             (ip->i_d.di_size != 0 || XFS_ISIZE(ip) != 0 ||
1911              ip->i_d.di_nextents > 0 || ip->i_delayed_blks > 0))
1912                 truncate = 1;
1913 
1914         error = xfs_qm_dqattach(ip, 0);
1915         if (error)
1916                 return;
1917 
1918         if (S_ISLNK(VFS_I(ip)->i_mode))
1919                 error = xfs_inactive_symlink(ip);
1920         else if (truncate)
1921                 error = xfs_inactive_truncate(ip);
1922         if (error)
1923                 return;
1924 
1925         /*
1926          * If there are attributes associated with the file then blow them away
1927          * now.  The code calls a routine that recursively deconstructs the
1928          * attribute fork. If also blows away the in-core attribute fork.
1929          */
1930         if (XFS_IFORK_Q(ip)) {
1931                 error = xfs_attr_inactive(ip);
1932                 if (error)
1933                         return;
1934         }
1935 
1936         ASSERT(!ip->i_afp);
1937         ASSERT(ip->i_d.di_anextents == 0);
1938         ASSERT(ip->i_d.di_forkoff == 0);
1939 
1940         /*
1941          * Free the inode.
1942          */
1943         error = xfs_inactive_ifree(ip);
1944         if (error)
1945                 return;
1946 
1947         /*
1948          * Release the dquots held by inode, if any.
1949          */
1950         xfs_qm_dqdetach(ip);
1951 }
1952 
1953 /*
1954  * This is called when the inode's link count goes to 0 or we are creating a
1955  * tmpfile via O_TMPFILE. In the case of a tmpfile, @ignore_linkcount will be
1956  * set to true as the link count is dropped to zero by the VFS after we've
1957  * created the file successfully, so we have to add it to the unlinked list
1958  * while the link count is non-zero.
1959  *
1960  * We place the on-disk inode on a list in the AGI.  It will be pulled from this
1961  * list when the inode is freed.
1962  */
1963 STATIC int
1964 xfs_iunlink(
1965         struct xfs_trans *tp,
1966         struct xfs_inode *ip)
1967 {
1968         xfs_mount_t     *mp = tp->t_mountp;
1969         xfs_agi_t       *agi;
1970         xfs_dinode_t    *dip;
1971         xfs_buf_t       *agibp;
1972         xfs_buf_t       *ibp;
1973         xfs_agino_t     agino;
1974         short           bucket_index;
1975         int             offset;
1976         int             error;
1977 
1978         ASSERT(VFS_I(ip)->i_mode != 0);
1979 
1980         /*
1981          * Get the agi buffer first.  It ensures lock ordering
1982          * on the list.
1983          */
1984         error = xfs_read_agi(mp, tp, XFS_INO_TO_AGNO(mp, ip->i_ino), &agibp);
1985         if (error)
1986                 return error;
1987         agi = XFS_BUF_TO_AGI(agibp);
1988 
1989         /*
1990          * Get the index into the agi hash table for the
1991          * list this inode will go on.
1992          */
1993         agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
1994         ASSERT(agino != 0);
1995         bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
1996         ASSERT(agi->agi_unlinked[bucket_index]);
1997         ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino);
1998 
1999         if (agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO)) {
2000                 /*
2001                  * There is already another inode in the bucket we need
2002                  * to add ourselves to.  Add us at the front of the list.
2003                  * Here we put the head pointer into our next pointer,
2004                  * and then we fall through to point the head at us.
2005                  */
2006                 error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2007                                        0, 0);
2008                 if (error)
2009                         return error;
2010 
2011                 ASSERT(dip->di_next_unlinked == cpu_to_be32(NULLAGINO));
2012                 dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
2013                 offset = ip->i_imap.im_boffset +
2014                         offsetof(xfs_dinode_t, di_next_unlinked);
2015 
2016                 /* need to recalc the inode CRC if appropriate */
2017                 xfs_dinode_calc_crc(mp, dip);
2018 
2019                 xfs_trans_inode_buf(tp, ibp);
2020                 xfs_trans_log_buf(tp, ibp, offset,
2021                                   (offset + sizeof(xfs_agino_t) - 1));
2022                 xfs_inobp_check(mp, ibp);
2023         }
2024 
2025         /*
2026          * Point the bucket head pointer at the inode being inserted.
2027          */
2028         ASSERT(agino != 0);
2029         agi->agi_unlinked[bucket_index] = cpu_to_be32(agino);
2030         offset = offsetof(xfs_agi_t, agi_unlinked) +
2031                 (sizeof(xfs_agino_t) * bucket_index);
2032         xfs_trans_log_buf(tp, agibp, offset,
2033                           (offset + sizeof(xfs_agino_t) - 1));
2034         return 0;
2035 }
2036 
2037 /*
2038  * Pull the on-disk inode from the AGI unlinked list.
2039  */
2040 STATIC int
2041 xfs_iunlink_remove(
2042         xfs_trans_t     *tp,
2043         xfs_inode_t     *ip)
2044 {
2045         xfs_ino_t       next_ino;
2046         xfs_mount_t     *mp;
2047         xfs_agi_t       *agi;
2048         xfs_dinode_t    *dip;
2049         xfs_buf_t       *agibp;
2050         xfs_buf_t       *ibp;
2051         xfs_agnumber_t  agno;
2052         xfs_agino_t     agino;
2053         xfs_agino_t     next_agino;
2054         xfs_buf_t       *last_ibp;
2055         xfs_dinode_t    *last_dip = NULL;
2056         short           bucket_index;
2057         int             offset, last_offset = 0;
2058         int             error;
2059 
2060         mp = tp->t_mountp;
2061         agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
2062 
2063         /*
2064          * Get the agi buffer first.  It ensures lock ordering
2065          * on the list.
2066          */
2067         error = xfs_read_agi(mp, tp, agno, &agibp);
2068         if (error)
2069                 return error;
2070 
2071         agi = XFS_BUF_TO_AGI(agibp);
2072 
2073         /*
2074          * Get the index into the agi hash table for the
2075          * list this inode will go on.
2076          */
2077         agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
2078         ASSERT(agino != 0);
2079         bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
2080         ASSERT(agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO));
2081         ASSERT(agi->agi_unlinked[bucket_index]);
2082 
2083         if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
2084                 /*
2085                  * We're at the head of the list.  Get the inode's on-disk
2086                  * buffer to see if there is anyone after us on the list.
2087                  * Only modify our next pointer if it is not already NULLAGINO.
2088                  * This saves us the overhead of dealing with the buffer when
2089                  * there is no need to change it.
2090                  */
2091                 error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2092                                        0, 0);
2093                 if (error) {
2094                         xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
2095                                 __func__, error);
2096                         return error;
2097                 }
2098                 next_agino = be32_to_cpu(dip->di_next_unlinked);
2099                 ASSERT(next_agino != 0);
2100                 if (next_agino != NULLAGINO) {
2101                         dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2102                         offset = ip->i_imap.im_boffset +
2103                                 offsetof(xfs_dinode_t, di_next_unlinked);
2104 
2105                         /* need to recalc the inode CRC if appropriate */
2106                         xfs_dinode_calc_crc(mp, dip);
2107 
2108                         xfs_trans_inode_buf(tp, ibp);
2109                         xfs_trans_log_buf(tp, ibp, offset,
2110                                           (offset + sizeof(xfs_agino_t) - 1));
2111                         xfs_inobp_check(mp, ibp);
2112                 } else {
2113                         xfs_trans_brelse(tp, ibp);
2114                 }
2115                 /*
2116                  * Point the bucket head pointer at the next inode.
2117                  */
2118                 ASSERT(next_agino != 0);
2119                 ASSERT(next_agino != agino);
2120                 agi->agi_unlinked[bucket_index] = cpu_to_be32(next_agino);
2121                 offset = offsetof(xfs_agi_t, agi_unlinked) +
2122                         (sizeof(xfs_agino_t) * bucket_index);
2123                 xfs_trans_log_buf(tp, agibp, offset,
2124                                   (offset + sizeof(xfs_agino_t) - 1));
2125         } else {
2126                 /*
2127                  * We need to search the list for the inode being freed.
2128                  */
2129                 next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
2130                 last_ibp = NULL;
2131                 while (next_agino != agino) {
2132                         struct xfs_imap imap;
2133 
2134                         if (last_ibp)
2135                                 xfs_trans_brelse(tp, last_ibp);
2136 
2137                         imap.im_blkno = 0;
2138                         next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
2139 
2140                         error = xfs_imap(mp, tp, next_ino, &imap, 0);
2141                         if (error) {
2142                                 xfs_warn(mp,
2143         "%s: xfs_imap returned error %d.",
2144                                          __func__, error);
2145                                 return error;
2146                         }
2147 
2148                         error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,
2149                                                &last_ibp, 0, 0);
2150                         if (error) {
2151                                 xfs_warn(mp,
2152         "%s: xfs_imap_to_bp returned error %d.",
2153                                         __func__, error);
2154                                 return error;
2155                         }
2156 
2157                         last_offset = imap.im_boffset;
2158                         next_agino = be32_to_cpu(last_dip->di_next_unlinked);
2159                         ASSERT(next_agino != NULLAGINO);
2160                         ASSERT(next_agino != 0);
2161                 }
2162 
2163                 /*
2164                  * Now last_ibp points to the buffer previous to us on the
2165                  * unlinked list.  Pull us from the list.
2166                  */
2167                 error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &ibp,
2168                                        0, 0);
2169                 if (error) {
2170                         xfs_warn(mp, "%s: xfs_imap_to_bp(2) returned error %d.",
2171                                 __func__, error);
2172                         return error;
2173                 }
2174                 next_agino = be32_to_cpu(dip->di_next_unlinked);
2175                 ASSERT(next_agino != 0);
2176                 ASSERT(next_agino != agino);
2177                 if (next_agino != NULLAGINO) {
2178                         dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
2179                         offset = ip->i_imap.im_boffset +
2180                                 offsetof(xfs_dinode_t, di_next_unlinked);
2181 
2182                         /* need to recalc the inode CRC if appropriate */
2183                         xfs_dinode_calc_crc(mp, dip);
2184 
2185                         xfs_trans_inode_buf(tp, ibp);
2186                         xfs_trans_log_buf(tp, ibp, offset,
2187                                           (offset + sizeof(xfs_agino_t) - 1));
2188                         xfs_inobp_check(mp, ibp);
2189                 } else {
2190                         xfs_trans_brelse(tp, ibp);
2191                 }
2192                 /*
2193                  * Point the previous inode on the list to the next inode.
2194                  */
2195                 last_dip->di_next_unlinked = cpu_to_be32(next_agino);
2196                 ASSERT(next_agino != 0);
2197                 offset = last_offset + offsetof(xfs_dinode_t, di_next_unlinked);
2198 
2199                 /* need to recalc the inode CRC if appropriate */
2200                 xfs_dinode_calc_crc(mp, last_dip);
2201 
2202                 xfs_trans_inode_buf(tp, last_ibp);
2203                 xfs_trans_log_buf(tp, last_ibp, offset,
2204                                   (offset + sizeof(xfs_agino_t) - 1));
2205                 xfs_inobp_check(mp, last_ibp);
2206         }
2207         return 0;
2208 }
2209 
2210 /*
2211  * A big issue when freeing the inode cluster is that we _cannot_ skip any
2212  * inodes that are in memory - they all must be marked stale and attached to
2213  * the cluster buffer.
2214  */
2215 STATIC int
2216 xfs_ifree_cluster(
2217         xfs_inode_t             *free_ip,
2218         xfs_trans_t             *tp,
2219         struct xfs_icluster     *xic)
2220 {
2221         xfs_mount_t             *mp = free_ip->i_mount;
2222         int                     blks_per_cluster;
2223         int                     inodes_per_cluster;
2224         int                     nbufs;
2225         int                     i, j;
2226         int                     ioffset;
2227         xfs_daddr_t             blkno;
2228         xfs_buf_t               *bp;
2229         xfs_inode_t             *ip;
2230         xfs_inode_log_item_t    *iip;
2231         struct xfs_log_item     *lip;
2232         struct xfs_perag        *pag;
2233         xfs_ino_t               inum;
2234 
2235         inum = xic->first_ino;
2236         pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, inum));
2237         blks_per_cluster = xfs_icluster_size_fsb(mp);
2238         inodes_per_cluster = blks_per_cluster << mp->m_sb.sb_inopblog;
2239         nbufs = mp->m_ialloc_blks / blks_per_cluster;
2240 
2241         for (j = 0; j < nbufs; j++, inum += inodes_per_cluster) {
2242                 /*
2243                  * The allocation bitmap tells us which inodes of the chunk were
2244                  * physically allocated. Skip the cluster if an inode falls into
2245                  * a sparse region.
2246                  */
2247                 ioffset = inum - xic->first_ino;
2248                 if ((xic->alloc & XFS_INOBT_MASK(ioffset)) == 0) {
2249                         ASSERT(do_mod(ioffset, inodes_per_cluster) == 0);
2250                         continue;
2251                 }
2252 
2253                 blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
2254                                          XFS_INO_TO_AGBNO(mp, inum));
2255 
2256                 /*
2257                  * We obtain and lock the backing buffer first in the process
2258                  * here, as we have to ensure that any dirty inode that we
2259                  * can't get the flush lock on is attached to the buffer.
2260                  * If we scan the in-memory inodes first, then buffer IO can
2261                  * complete before we get a lock on it, and hence we may fail
2262                  * to mark all the active inodes on the buffer stale.
2263                  */
2264                 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
2265                                         mp->m_bsize * blks_per_cluster,
2266                                         XBF_UNMAPPED);
2267 
2268                 if (!bp)
2269                         return -ENOMEM;
2270 
2271                 /*
2272                  * This buffer may not have been correctly initialised as we
2273                  * didn't read it from disk. That's not important because we are
2274                  * only using to mark the buffer as stale in the log, and to
2275                  * attach stale cached inodes on it. That means it will never be
2276                  * dispatched for IO. If it is, we want to know about it, and we
2277                  * want it to fail. We can acheive this by adding a write
2278                  * verifier to the buffer.
2279                  */
2280                  bp->b_ops = &xfs_inode_buf_ops;
2281 
2282                 /*
2283                  * Walk the inodes already attached to the buffer and mark them
2284                  * stale. These will all have the flush locks held, so an
2285                  * in-memory inode walk can't lock them. By marking them all
2286                  * stale first, we will not attempt to lock them in the loop
2287                  * below as the XFS_ISTALE flag will be set.
2288                  */
2289                 list_for_each_entry(lip, &bp->b_li_list, li_bio_list) {
2290                         if (lip->li_type == XFS_LI_INODE) {
2291                                 iip = (xfs_inode_log_item_t *)lip;
2292                                 ASSERT(iip->ili_logged == 1);
2293                                 lip->li_cb = xfs_istale_done;
2294                                 xfs_trans_ail_copy_lsn(mp->m_ail,
2295                                                         &iip->ili_flush_lsn,
2296                                                         &iip->ili_item.li_lsn);
2297                                 xfs_iflags_set(iip->ili_inode, XFS_ISTALE);
2298                         }
2299                 }
2300 
2301 
2302                 /*
2303                  * For each inode in memory attempt to add it to the inode
2304                  * buffer and set it up for being staled on buffer IO
2305                  * completion.  This is safe as we've locked out tail pushing
2306                  * and flushing by locking the buffer.
2307                  *
2308                  * We have already marked every inode that was part of a
2309                  * transaction stale above, which means there is no point in
2310                  * even trying to lock them.
2311                  */
2312                 for (i = 0; i < inodes_per_cluster; i++) {
2313 retry:
2314                         rcu_read_lock();
2315                         ip = radix_tree_lookup(&pag->pag_ici_root,
2316                                         XFS_INO_TO_AGINO(mp, (inum + i)));
2317 
2318                         /* Inode not in memory, nothing to do */
2319                         if (!ip) {
2320                                 rcu_read_unlock();
2321                                 continue;
2322                         }
2323 
2324                         /*
2325                          * because this is an RCU protected lookup, we could
2326                          * find a recently freed or even reallocated inode
2327                          * during the lookup. We need to check under the
2328                          * i_flags_lock for a valid inode here. Skip it if it
2329                          * is not valid, the wrong inode or stale.
2330                          */
2331                         spin_lock(&ip->i_flags_lock);
2332                         if (ip->i_ino != inum + i ||
2333                             __xfs_iflags_test(ip, XFS_ISTALE)) {
2334                                 spin_unlock(&ip->i_flags_lock);
2335                                 rcu_read_unlock();
2336                                 continue;
2337                         }
2338                         spin_unlock(&ip->i_flags_lock);
2339 
2340                         /*
2341                          * Don't try to lock/unlock the current inode, but we
2342                          * _cannot_ skip the other inodes that we did not find
2343                          * in the list attached to the buffer and are not
2344                          * already marked stale. If we can't lock it, back off
2345                          * and retry.
2346                          */
2347                         if (ip != free_ip) {
2348                                 if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
2349                                         rcu_read_unlock();
2350                                         delay(1);
2351                                         goto retry;
2352                                 }
2353 
2354                                 /*
2355                                  * Check the inode number again in case we're
2356                                  * racing with freeing in xfs_reclaim_inode().
2357                                  * See the comments in that function for more
2358                                  * information as to why the initial check is
2359                                  * not sufficient.
2360                                  */
2361                                 if (ip->i_ino != inum + i) {
2362                                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
2363                                         rcu_read_unlock();
2364                                         continue;
2365                                 }
2366                         }
2367                         rcu_read_unlock();
2368 
2369                         xfs_iflock(ip);
2370                         xfs_iflags_set(ip, XFS_ISTALE);
2371 
2372                         /*
2373                          * we don't need to attach clean inodes or those only
2374                          * with unlogged changes (which we throw away, anyway).
2375                          */
2376                         iip = ip->i_itemp;
2377                         if (!iip || xfs_inode_clean(ip)) {
2378                                 ASSERT(ip != free_ip);
2379                                 xfs_ifunlock(ip);
2380                                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
2381                                 continue;
2382                         }
2383 
2384                         iip->ili_last_fields = iip->ili_fields;
2385                         iip->ili_fields = 0;
2386                         iip->ili_fsync_fields = 0;
2387                         iip->ili_logged = 1;
2388                         xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
2389                                                 &iip->ili_item.li_lsn);
2390 
2391                         xfs_buf_attach_iodone(bp, xfs_istale_done,
2392                                                   &iip->ili_item);
2393 
2394                         if (ip != free_ip)
2395                                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
2396                 }
2397 
2398                 xfs_trans_stale_inode_buf(tp, bp);
2399                 xfs_trans_binval(tp, bp);
2400         }
2401 
2402         xfs_perag_put(pag);
2403         return 0;
2404 }
2405 
2406 /*
2407  * Free any local-format buffers sitting around before we reset to
2408  * extents format.
2409  */
2410 static inline void
2411 xfs_ifree_local_data(
2412         struct xfs_inode        *ip,
2413         int                     whichfork)
2414 {
2415         struct xfs_ifork        *ifp;
2416 
2417         if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL)
2418                 return;
2419 
2420         ifp = XFS_IFORK_PTR(ip, whichfork);
2421         xfs_idata_realloc(ip, -ifp->if_bytes, whichfork);
2422 }
2423 
2424 /*
2425  * This is called to return an inode to the inode free list.
2426  * The inode should already be truncated to 0 length and have
2427  * no pages associated with it.  This routine also assumes that
2428  * the inode is already a part of the transaction.
2429  *
2430  * The on-disk copy of the inode will have been added to the list
2431  * of unlinked inodes in the AGI. We need to remove the inode from
2432  * that list atomically with respect to freeing it here.
2433  */
2434 int
2435 xfs_ifree(
2436         xfs_trans_t     *tp,
2437         xfs_inode_t     *ip,
2438         struct xfs_defer_ops    *dfops)
2439 {
2440         int                     error;
2441         struct xfs_icluster     xic = { 0 };
2442 
2443         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
2444         ASSERT(VFS_I(ip)->i_nlink == 0);
2445         ASSERT(ip->i_d.di_nextents == 0);
2446         ASSERT(ip->i_d.di_anextents == 0);
2447         ASSERT(ip->i_d.di_size == 0 || !S_ISREG(VFS_I(ip)->i_mode));
2448         ASSERT(ip->i_d.di_nblocks == 0);
2449 
2450         /*
2451          * Pull the on-disk inode from the AGI unlinked list.
2452          */
2453         error = xfs_iunlink_remove(tp, ip);
2454         if (error)
2455                 return error;
2456 
2457         error = xfs_difree(tp, ip->i_ino, dfops, &xic);
2458         if (error)
2459                 return error;
2460 
2461         xfs_ifree_local_data(ip, XFS_DATA_FORK);
2462         xfs_ifree_local_data(ip, XFS_ATTR_FORK);
2463 
2464         VFS_I(ip)->i_mode = 0;          /* mark incore inode as free */
2465         ip->i_d.di_flags = 0;
2466         ip->i_d.di_flags2 = 0;
2467         ip->i_d.di_dmevmask = 0;
2468         ip->i_d.di_forkoff = 0;         /* mark the attr fork not in use */
2469         ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
2470         ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
2471 
2472         /* Don't attempt to replay owner changes for a deleted inode */
2473         ip->i_itemp->ili_fields &= ~(XFS_ILOG_AOWNER|XFS_ILOG_DOWNER);
2474 
2475         /*
2476          * Bump the generation count so no one will be confused
2477          * by reincarnations of this inode.
2478          */
2479         VFS_I(ip)->i_generation++;
2480         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2481 
2482         if (xic.deleted)
2483                 error = xfs_ifree_cluster(ip, tp, &xic);
2484 
2485         return error;
2486 }
2487 
2488 /*
2489  * This is called to unpin an inode.  The caller must have the inode locked
2490  * in at least shared mode so that the buffer cannot be subsequently pinned
2491  * once someone is waiting for it to be unpinned.
2492  */
2493 static void
2494 xfs_iunpin(
2495         struct xfs_inode        *ip)
2496 {
2497         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
2498 
2499         trace_xfs_inode_unpin_nowait(ip, _RET_IP_);
2500 
2501         /* Give the log a push to start the unpinning I/O */
2502         xfs_log_force_lsn(ip->i_mount, ip->i_itemp->ili_last_lsn, 0, NULL);
2503 
2504 }
2505 
2506 static void
2507 __xfs_iunpin_wait(
2508         struct xfs_inode        *ip)
2509 {
2510         wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IPINNED_BIT);
2511         DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IPINNED_BIT);
2512 
2513         xfs_iunpin(ip);
2514 
2515         do {
2516                 prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
2517                 if (xfs_ipincount(ip))
2518                         io_schedule();
2519         } while (xfs_ipincount(ip));
2520         finish_wait(wq, &wait.wq_entry);
2521 }
2522 
2523 void
2524 xfs_iunpin_wait(
2525         struct xfs_inode        *ip)
2526 {
2527         if (xfs_ipincount(ip))
2528                 __xfs_iunpin_wait(ip);
2529 }
2530 
2531 /*
2532  * Removing an inode from the namespace involves removing the directory entry
2533  * and dropping the link count on the inode. Removing the directory entry can
2534  * result in locking an AGF (directory blocks were freed) and removing a link
2535  * count can result in placing the inode on an unlinked list which results in
2536  * locking an AGI.
2537  *
2538  * The big problem here is that we have an ordering constraint on AGF and AGI
2539  * locking - inode allocation locks the AGI, then can allocate a new extent for
2540  * new inodes, locking the AGF after the AGI. Similarly, freeing the inode
2541  * removes the inode from the unlinked list, requiring that we lock the AGI
2542  * first, and then freeing the inode can result in an inode chunk being freed
2543  * and hence freeing disk space requiring that we lock an AGF.
2544  *
2545  * Hence the ordering that is imposed by other parts of the code is AGI before
2546  * AGF. This means we cannot remove the directory entry before we drop the inode
2547  * reference count and put it on the unlinked list as this results in a lock
2548  * order of AGF then AGI, and this can deadlock against inode allocation and
2549  * freeing. Therefore we must drop the link counts before we remove the
2550  * directory entry.
2551  *
2552  * This is still safe from a transactional point of view - it is not until we
2553  * get to xfs_defer_finish() that we have the possibility of multiple
2554  * transactions in this operation. Hence as long as we remove the directory
2555  * entry and drop the link count in the first transaction of the remove
2556  * operation, there are no transactional constraints on the ordering here.
2557  */
2558 int
2559 xfs_remove(
2560         xfs_inode_t             *dp,
2561         struct xfs_name         *name,
2562         xfs_inode_t             *ip)
2563 {
2564         xfs_mount_t             *mp = dp->i_mount;
2565         xfs_trans_t             *tp = NULL;
2566         int                     is_dir = S_ISDIR(VFS_I(ip)->i_mode);
2567         int                     error = 0;
2568         struct xfs_defer_ops    dfops;
2569         xfs_fsblock_t           first_block;
2570         uint                    resblks;
2571 
2572         trace_xfs_remove(dp, name);
2573 
2574         if (XFS_FORCED_SHUTDOWN(mp))
2575                 return -EIO;
2576 
2577         error = xfs_qm_dqattach(dp, 0);
2578         if (error)
2579                 goto std_return;
2580 
2581         error = xfs_qm_dqattach(ip, 0);
2582         if (error)
2583                 goto std_return;
2584 
2585         /*
2586          * We try to get the real space reservation first,
2587          * allowing for directory btree deletion(s) implying
2588          * possible bmap insert(s).  If we can't get the space
2589          * reservation then we use 0 instead, and avoid the bmap
2590          * btree insert(s) in the directory code by, if the bmap
2591          * insert tries to happen, instead trimming the LAST
2592          * block from the directory.
2593          */
2594         resblks = XFS_REMOVE_SPACE_RES(mp);
2595         error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, resblks, 0, 0, &tp);
2596         if (error == -ENOSPC) {
2597                 resblks = 0;
2598                 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remove, 0, 0, 0,
2599                                 &tp);
2600         }
2601         if (error) {
2602                 ASSERT(error != -ENOSPC);
2603                 goto std_return;
2604         }
2605 
2606         xfs_lock_two_inodes(dp, XFS_ILOCK_EXCL, ip, XFS_ILOCK_EXCL);
2607 
2608         xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
2609         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
2610 
2611         /*
2612          * If we're removing a directory perform some additional validation.
2613          */
2614         if (is_dir) {
2615                 ASSERT(VFS_I(ip)->i_nlink >= 2);
2616                 if (VFS_I(ip)->i_nlink != 2) {
2617                         error = -ENOTEMPTY;
2618                         goto out_trans_cancel;
2619                 }
2620                 if (!xfs_dir_isempty(ip)) {
2621                         error = -ENOTEMPTY;
2622                         goto out_trans_cancel;
2623                 }
2624 
2625                 /* Drop the link from ip's "..".  */
2626                 error = xfs_droplink(tp, dp);
2627                 if (error)
2628                         goto out_trans_cancel;
2629 
2630                 /* Drop the "." link from ip to self.  */
2631                 error = xfs_droplink(tp, ip);
2632                 if (error)
2633                         goto out_trans_cancel;
2634         } else {
2635                 /*
2636                  * When removing a non-directory we need to log the parent
2637                  * inode here.  For a directory this is done implicitly
2638                  * by the xfs_droplink call for the ".." entry.
2639                  */
2640                 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
2641         }
2642         xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2643 
2644         /* Drop the link from dp to ip. */
2645         error = xfs_droplink(tp, ip);
2646         if (error)
2647                 goto out_trans_cancel;
2648 
2649         xfs_defer_init(&dfops, &first_block);
2650         error = xfs_dir_removename(tp, dp, name, ip->i_ino,
2651                                         &first_block, &dfops, resblks);
2652         if (error) {
2653                 ASSERT(error != -ENOENT);
2654                 goto out_bmap_cancel;
2655         }
2656 
2657         /*
2658          * If this is a synchronous mount, make sure that the
2659          * remove transaction goes to disk before returning to
2660          * the user.
2661          */
2662         if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2663                 xfs_trans_set_sync(tp);
2664 
2665         error = xfs_defer_finish(&tp, &dfops);
2666         if (error)
2667                 goto out_bmap_cancel;
2668 
2669         error = xfs_trans_commit(tp);
2670         if (error)
2671                 goto std_return;
2672 
2673         if (is_dir && xfs_inode_is_filestream(ip))
2674                 xfs_filestream_deassociate(ip);
2675 
2676         return 0;
2677 
2678  out_bmap_cancel:
2679         xfs_defer_cancel(&dfops);
2680  out_trans_cancel:
2681         xfs_trans_cancel(tp);
2682  std_return:
2683         return error;
2684 }
2685 
2686 /*
2687  * Enter all inodes for a rename transaction into a sorted array.
2688  */
2689 #define __XFS_SORT_INODES       5
2690 STATIC void
2691 xfs_sort_for_rename(
2692         struct xfs_inode        *dp1,   /* in: old (source) directory inode */
2693         struct xfs_inode        *dp2,   /* in: new (target) directory inode */
2694         struct xfs_inode        *ip1,   /* in: inode of old entry */
2695         struct xfs_inode        *ip2,   /* in: inode of new entry */
2696         struct xfs_inode        *wip,   /* in: whiteout inode */
2697         struct xfs_inode        **i_tab,/* out: sorted array of inodes */
2698         int                     *num_inodes)  /* in/out: inodes in array */
2699 {
2700         int                     i, j;
2701 
2702         ASSERT(*num_inodes == __XFS_SORT_INODES);
2703         memset(i_tab, 0, *num_inodes * sizeof(struct xfs_inode *));
2704 
2705         /*
2706          * i_tab contains a list of pointers to inodes.  We initialize
2707          * the table here & we'll sort it.  We will then use it to
2708          * order the acquisition of the inode locks.
2709          *
2710          * Note that the table may contain duplicates.  e.g., dp1 == dp2.
2711          */
2712         i = 0;
2713         i_tab[i++] = dp1;
2714         i_tab[i++] = dp2;
2715         i_tab[i++] = ip1;
2716         if (ip2)
2717                 i_tab[i++] = ip2;
2718         if (wip)
2719                 i_tab[i++] = wip;
2720         *num_inodes = i;
2721 
2722         /*
2723          * Sort the elements via bubble sort.  (Remember, there are at
2724          * most 5 elements to sort, so this is adequate.)
2725          */
2726         for (i = 0; i < *num_inodes; i++) {
2727                 for (j = 1; j < *num_inodes; j++) {
2728                         if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
2729                                 struct xfs_inode *temp = i_tab[j];
2730                                 i_tab[j] = i_tab[j-1];
2731                                 i_tab[j-1] = temp;
2732                         }
2733                 }
2734         }
2735 }
2736 
2737 static int
2738 xfs_finish_rename(
2739         struct xfs_trans        *tp,
2740         struct xfs_defer_ops    *dfops)
2741 {
2742         int                     error;
2743 
2744         /*
2745          * If this is a synchronous mount, make sure that the rename transaction
2746          * goes to disk before returning to the user.
2747          */
2748         if (tp->t_mountp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
2749                 xfs_trans_set_sync(tp);
2750 
2751         error = xfs_defer_finish(&tp, dfops);
2752         if (error) {
2753                 xfs_defer_cancel(dfops);
2754                 xfs_trans_cancel(tp);
2755                 return error;
2756         }
2757 
2758         return xfs_trans_commit(tp);
2759 }
2760 
2761 /*
2762  * xfs_cross_rename()
2763  *
2764  * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall
2765  */
2766 STATIC int
2767 xfs_cross_rename(
2768         struct xfs_trans        *tp,
2769         struct xfs_inode        *dp1,
2770         struct xfs_name         *name1,
2771         struct xfs_inode        *ip1,
2772         struct xfs_inode        *dp2,
2773         struct xfs_name         *name2,
2774         struct xfs_inode        *ip2,
2775         struct xfs_defer_ops    *dfops,
2776         xfs_fsblock_t           *first_block,
2777         int                     spaceres)
2778 {
2779         int             error = 0;
2780         int             ip1_flags = 0;
2781         int             ip2_flags = 0;
2782         int             dp2_flags = 0;
2783 
2784         /* Swap inode number for dirent in first parent */
2785         error = xfs_dir_replace(tp, dp1, name1,
2786                                 ip2->i_ino,
2787                                 first_block, dfops, spaceres);
2788         if (error)
2789                 goto out_trans_abort;
2790 
2791         /* Swap inode number for dirent in second parent */
2792         error = xfs_dir_replace(tp, dp2, name2,
2793                                 ip1->i_ino,
2794                                 first_block, dfops, spaceres);
2795         if (error)
2796                 goto out_trans_abort;
2797 
2798         /*
2799          * If we're renaming one or more directories across different parents,
2800          * update the respective ".." entries (and link counts) to match the new
2801          * parents.
2802          */
2803         if (dp1 != dp2) {
2804                 dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2805 
2806                 if (S_ISDIR(VFS_I(ip2)->i_mode)) {
2807                         error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
2808                                                 dp1->i_ino, first_block,
2809                                                 dfops, spaceres);
2810                         if (error)
2811                                 goto out_trans_abort;
2812 
2813                         /* transfer ip2 ".." reference to dp1 */
2814                         if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
2815                                 error = xfs_droplink(tp, dp2);
2816                                 if (error)
2817                                         goto out_trans_abort;
2818                                 error = xfs_bumplink(tp, dp1);
2819                                 if (error)
2820                                         goto out_trans_abort;
2821                         }
2822 
2823                         /*
2824                          * Although ip1 isn't changed here, userspace needs
2825                          * to be warned about the change, so that applications
2826                          * relying on it (like backup ones), will properly
2827                          * notify the change
2828                          */
2829                         ip1_flags |= XFS_ICHGTIME_CHG;
2830                         ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2831                 }
2832 
2833                 if (S_ISDIR(VFS_I(ip1)->i_mode)) {
2834                         error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
2835                                                 dp2->i_ino, first_block,
2836                                                 dfops, spaceres);
2837                         if (error)
2838                                 goto out_trans_abort;
2839 
2840                         /* transfer ip1 ".." reference to dp2 */
2841                         if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
2842                                 error = xfs_droplink(tp, dp1);
2843                                 if (error)
2844                                         goto out_trans_abort;
2845                                 error = xfs_bumplink(tp, dp2);
2846                                 if (error)
2847                                         goto out_trans_abort;
2848                         }
2849 
2850                         /*
2851                          * Although ip2 isn't changed here, userspace needs
2852                          * to be warned about the change, so that applications
2853                          * relying on it (like backup ones), will properly
2854                          * notify the change
2855                          */
2856                         ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
2857                         ip2_flags |= XFS_ICHGTIME_CHG;
2858                 }
2859         }
2860 
2861         if (ip1_flags) {
2862                 xfs_trans_ichgtime(tp, ip1, ip1_flags);
2863                 xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
2864         }
2865         if (ip2_flags) {
2866                 xfs_trans_ichgtime(tp, ip2, ip2_flags);
2867                 xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
2868         }
2869         if (dp2_flags) {
2870                 xfs_trans_ichgtime(tp, dp2, dp2_flags);
2871                 xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
2872         }
2873         xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
2874         xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
2875         return xfs_finish_rename(tp, dfops);
2876 
2877 out_trans_abort:
2878         xfs_defer_cancel(dfops);
2879         xfs_trans_cancel(tp);
2880         return error;
2881 }
2882 
2883 /*
2884  * xfs_rename_alloc_whiteout()
2885  *
2886  * Return a referenced, unlinked, unlocked inode that that can be used as a
2887  * whiteout in a rename transaction. We use a tmpfile inode here so that if we
2888  * crash between allocating the inode and linking it into the rename transaction
2889  * recovery will free the inode and we won't leak it.
2890  */
2891 static int
2892 xfs_rename_alloc_whiteout(
2893         struct xfs_inode        *dp,
2894         struct xfs_inode        **wip)
2895 {
2896         struct xfs_inode        *tmpfile;
2897         int                     error;
2898 
2899         error = xfs_create_tmpfile(dp, S_IFCHR | WHITEOUT_MODE, &tmpfile);
2900         if (error)
2901                 return error;
2902 
2903         /*
2904          * Prepare the tmpfile inode as if it were created through the VFS.
2905          * Otherwise, the link increment paths will complain about nlink 0->1.
2906          * Drop the link count as done by d_tmpfile(), complete the inode setup
2907          * and flag it as linkable.
2908          */
2909         drop_nlink(VFS_I(tmpfile));
2910         xfs_setup_iops(tmpfile);
2911         xfs_finish_inode_setup(tmpfile);
2912         VFS_I(tmpfile)->i_state |= I_LINKABLE;
2913 
2914         *wip = tmpfile;
2915         return 0;
2916 }
2917 
2918 /*
2919  * xfs_rename
2920  */
2921 int
2922 xfs_rename(
2923         struct xfs_inode        *src_dp,
2924         struct xfs_name         *src_name,
2925         struct xfs_inode        *src_ip,
2926         struct xfs_inode        *target_dp,
2927         struct xfs_name         *target_name,
2928         struct xfs_inode        *target_ip,
2929         unsigned int            flags)
2930 {
2931         struct xfs_mount        *mp = src_dp->i_mount;
2932         struct xfs_trans        *tp;
2933         struct xfs_defer_ops    dfops;
2934         xfs_fsblock_t           first_block;
2935         struct xfs_inode        *wip = NULL;            /* whiteout inode */
2936         struct xfs_inode        *inodes[__XFS_SORT_INODES];
2937         int                     num_inodes = __XFS_SORT_INODES;
2938         bool                    new_parent = (src_dp != target_dp);
2939         bool                    src_is_directory = S_ISDIR(VFS_I(src_ip)->i_mode);
2940         int                     spaceres;
2941         int                     error;
2942 
2943         trace_xfs_rename(src_dp, target_dp, src_name, target_name);
2944 
2945         if ((flags & RENAME_EXCHANGE) && !target_ip)
2946                 return -EINVAL;
2947 
2948         /*
2949          * If we are doing a whiteout operation, allocate the whiteout inode
2950          * we will be placing at the target and ensure the type is set
2951          * appropriately.
2952          */
2953         if (flags & RENAME_WHITEOUT) {
2954                 ASSERT(!(flags & (RENAME_NOREPLACE | RENAME_EXCHANGE)));
2955                 error = xfs_rename_alloc_whiteout(target_dp, &wip);
2956                 if (error)
2957                         return error;
2958 
2959                 /* setup target dirent info as whiteout */
2960                 src_name->type = XFS_DIR3_FT_CHRDEV;
2961         }
2962 
2963         xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip, wip,
2964                                 inodes, &num_inodes);
2965 
2966         spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
2967         error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, spaceres, 0, 0, &tp);
2968         if (error == -ENOSPC) {
2969                 spaceres = 0;
2970                 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_rename, 0, 0, 0,
2971                                 &tp);
2972         }
2973         if (error)
2974                 goto out_release_wip;
2975 
2976         /*
2977          * Attach the dquots to the inodes
2978          */
2979         error = xfs_qm_vop_rename_dqattach(inodes);
2980         if (error)
2981                 goto out_trans_cancel;
2982 
2983         /*
2984          * Lock all the participating inodes. Depending upon whether
2985          * the target_name exists in the target directory, and
2986          * whether the target directory is the same as the source
2987          * directory, we can lock from 2 to 4 inodes.
2988          */
2989         xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
2990 
2991         /*
2992          * Join all the inodes to the transaction. From this point on,
2993          * we can rely on either trans_commit or trans_cancel to unlock
2994          * them.
2995          */
2996         xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
2997         if (new_parent)
2998                 xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
2999         xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
3000         if (target_ip)
3001                 xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
3002         if (wip)
3003                 xfs_trans_ijoin(tp, wip, XFS_ILOCK_EXCL);
3004 
3005         /*
3006          * If we are using project inheritance, we only allow renames
3007          * into our tree when the project IDs are the same; else the
3008          * tree quota mechanism would be circumvented.
3009          */
3010         if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
3011                      (xfs_get_projid(target_dp) != xfs_get_projid(src_ip)))) {
3012                 error = -EXDEV;
3013                 goto out_trans_cancel;
3014         }
3015 
3016         xfs_defer_init(&dfops, &first_block);
3017 
3018         /* RENAME_EXCHANGE is unique from here on. */
3019         if (flags & RENAME_EXCHANGE)
3020                 return xfs_cross_rename(tp, src_dp, src_name, src_ip,
3021                                         target_dp, target_name, target_ip,
3022                                         &dfops, &first_block, spaceres);
3023 
3024         /*
3025          * Set up the target.
3026          */
3027         if (target_ip == NULL) {
3028                 /*
3029                  * If there's no space reservation, check the entry will
3030                  * fit before actually inserting it.
3031                  */
3032                 if (!spaceres) {
3033                         error = xfs_dir_canenter(tp, target_dp, target_name);
3034                         if (error)
3035                                 goto out_trans_cancel;
3036                 }
3037                 /*
3038                  * If target does not exist and the rename crosses
3039                  * directories, adjust the target directory link count
3040                  * to account for the ".." reference from the new entry.
3041                  */
3042                 error = xfs_dir_createname(tp, target_dp, target_name,
3043                                                 src_ip->i_ino, &first_block,
3044                                                 &dfops, spaceres);
3045                 if (error)
3046                         goto out_bmap_cancel;
3047 
3048                 xfs_trans_ichgtime(tp, target_dp,
3049                                         XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3050 
3051                 if (new_parent && src_is_directory) {
3052                         error = xfs_bumplink(tp, target_dp);
3053                         if (error)
3054                                 goto out_bmap_cancel;
3055                 }
3056         } else { /* target_ip != NULL */
3057                 /*
3058                  * If target exists and it's a directory, check that both
3059                  * target and source are directories and that target can be
3060                  * destroyed, or that neither is a directory.
3061                  */
3062                 if (S_ISDIR(VFS_I(target_ip)->i_mode)) {
3063                         /*
3064                          * Make sure target dir is empty.
3065                          */
3066                         if (!(xfs_dir_isempty(target_ip)) ||
3067                             (VFS_I(target_ip)->i_nlink > 2)) {
3068                                 error = -EEXIST;
3069                                 goto out_trans_cancel;
3070                         }
3071                 }
3072 
3073                 /*
3074                  * Link the source inode under the target name.
3075                  * If the source inode is a directory and we are moving
3076                  * it across directories, its ".." entry will be
3077                  * inconsistent until we replace that down below.
3078                  *
3079                  * In case there is already an entry with the same
3080                  * name at the destination directory, remove it first.
3081                  */
3082                 error = xfs_dir_replace(tp, target_dp, target_name,
3083                                         src_ip->i_ino,
3084                                         &first_block, &dfops, spaceres);
3085                 if (error)
3086                         goto out_bmap_cancel;
3087 
3088                 xfs_trans_ichgtime(tp, target_dp,
3089                                         XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3090 
3091                 /*
3092                  * Decrement the link count on the target since the target
3093                  * dir no longer points to it.
3094                  */
3095                 error = xfs_droplink(tp, target_ip);
3096                 if (error)
3097                         goto out_bmap_cancel;
3098 
3099                 if (src_is_directory) {
3100                         /*
3101                          * Drop the link from the old "." entry.
3102                          */
3103                         error = xfs_droplink(tp, target_ip);
3104                         if (error)
3105                                 goto out_bmap_cancel;
3106                 }
3107         } /* target_ip != NULL */
3108 
3109         /*
3110          * Remove the source.
3111          */
3112         if (new_parent && src_is_directory) {
3113                 /*
3114                  * Rewrite the ".." entry to point to the new
3115                  * directory.
3116                  */
3117                 error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
3118                                         target_dp->i_ino,
3119                                         &first_block, &dfops, spaceres);
3120                 ASSERT(error != -EEXIST);
3121                 if (error)
3122                         goto out_bmap_cancel;
3123         }
3124 
3125         /*
3126          * We always want to hit the ctime on the source inode.
3127          *
3128          * This isn't strictly required by the standards since the source
3129          * inode isn't really being changed, but old unix file systems did
3130          * it and some incremental backup programs won't work without it.
3131          */
3132         xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
3133         xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
3134 
3135         /*
3136          * Adjust the link count on src_dp.  This is necessary when
3137          * renaming a directory, either within one parent when
3138          * the target existed, or across two parent directories.
3139          */
3140         if (src_is_directory && (new_parent || target_ip != NULL)) {
3141 
3142                 /*
3143                  * Decrement link count on src_directory since the
3144                  * entry that's moved no longer points to it.
3145                  */
3146                 error = xfs_droplink(tp, src_dp);
3147                 if (error)
3148                         goto out_bmap_cancel;
3149         }
3150 
3151         /*
3152          * For whiteouts, we only need to update the source dirent with the
3153          * inode number of the whiteout inode rather than removing it
3154          * altogether.
3155          */
3156         if (wip) {
3157                 error = xfs_dir_replace(tp, src_dp, src_name, wip->i_ino,
3158                                         &first_block, &dfops, spaceres);
3159         } else
3160                 error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
3161                                            &first_block, &dfops, spaceres);
3162         if (error)
3163                 goto out_bmap_cancel;
3164 
3165         /*
3166          * For whiteouts, we need to bump the link count on the whiteout inode.
3167          * This means that failures all the way up to this point leave the inode
3168          * on the unlinked list and so cleanup is a simple matter of dropping
3169          * the remaining reference to it. If we fail here after bumping the link
3170          * count, we're shutting down the filesystem so we'll never see the
3171          * intermediate state on disk.
3172          */
3173         if (wip) {
3174                 ASSERT(VFS_I(wip)->i_nlink == 0);
3175                 error = xfs_bumplink(tp, wip);
3176                 if (error)
3177                         goto out_bmap_cancel;
3178                 error = xfs_iunlink_remove(tp, wip);
3179                 if (error)
3180                         goto out_bmap_cancel;
3181                 xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE);
3182 
3183                 /*
3184                  * Now we have a real link, clear the "I'm a tmpfile" state
3185                  * flag from the inode so it doesn't accidentally get misused in
3186                  * future.
3187                  */
3188                 VFS_I(wip)->i_state &= ~I_LINKABLE;
3189         }
3190 
3191         xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
3192         xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
3193         if (new_parent)
3194                 xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
3195 
3196         error = xfs_finish_rename(tp, &dfops);
3197         if (wip)
3198                 IRELE(wip);
3199         return error;
3200 
3201 out_bmap_cancel:
3202         xfs_defer_cancel(&dfops);
3203 out_trans_cancel:
3204         xfs_trans_cancel(tp);
3205 out_release_wip:
3206         if (wip)
3207                 IRELE(wip);
3208         return error;
3209 }
3210 
3211 STATIC int
3212 xfs_iflush_cluster(
3213         struct xfs_inode        *ip,
3214         struct xfs_buf          *bp)
3215 {
3216         struct xfs_mount        *mp = ip->i_mount;
3217         struct xfs_perag        *pag;
3218         unsigned long           first_index, mask;
3219         unsigned long           inodes_per_cluster;
3220         int                     cilist_size;
3221         struct xfs_inode        **cilist;
3222         struct xfs_inode        *cip;
3223         int                     nr_found;
3224         int                     clcount = 0;
3225         int                     bufwasdelwri;
3226         int                     i;
3227 
3228         pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
3229 
3230         inodes_per_cluster = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;
3231         cilist_size = inodes_per_cluster * sizeof(xfs_inode_t *);
3232         cilist = kmem_alloc(cilist_size, KM_MAYFAIL|KM_NOFS);
3233         if (!cilist)
3234                 goto out_put;
3235 
3236         mask = ~(((mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog)) - 1);
3237         first_index = XFS_INO_TO_AGINO(mp, ip->i_ino) & mask;
3238         rcu_read_lock();
3239         /* really need a gang lookup range call here */
3240         nr_found = radix_tree_gang_lookup(&pag->pag_ici_root, (void**)cilist,
3241                                         first_index, inodes_per_cluster);
3242         if (nr_found == 0)
3243                 goto out_free;
3244 
3245         for (i = 0; i < nr_found; i++) {
3246                 cip = cilist[i];
3247                 if (cip == ip)
3248                         continue;
3249 
3250                 /*
3251                  * because this is an RCU protected lookup, we could find a
3252                  * recently freed or even reallocated inode during the lookup.
3253                  * We need to check under the i_flags_lock for a valid inode
3254                  * here. Skip it if it is not valid or the wrong inode.
3255                  */
3256                 spin_lock(&cip->i_flags_lock);
3257                 if (!cip->i_ino ||
3258                     __xfs_iflags_test(cip, XFS_ISTALE)) {
3259                         spin_unlock(&cip->i_flags_lock);
3260                         continue;
3261                 }
3262 
3263                 /*
3264                  * Once we fall off the end of the cluster, no point checking
3265                  * any more inodes in the list because they will also all be
3266                  * outside the cluster.
3267                  */
3268                 if ((XFS_INO_TO_AGINO(mp, cip->i_ino) & mask) != first_index) {
3269                         spin_unlock(&cip->i_flags_lock);
3270                         break;
3271                 }
3272                 spin_unlock(&cip->i_flags_lock);
3273 
3274                 /*
3275                  * Do an un-protected check to see if the inode is dirty and
3276                  * is a candidate for flushing.  These checks will be repeated
3277                  * later after the appropriate locks are acquired.
3278                  */
3279                 if (xfs_inode_clean(cip) && xfs_ipincount(cip) == 0)
3280                         continue;
3281 
3282                 /*
3283                  * Try to get locks.  If any are unavailable or it is pinned,
3284                  * then this inode cannot be flushed and is skipped.
3285                  */
3286 
3287                 if (!xfs_ilock_nowait(cip, XFS_ILOCK_SHARED))
3288                         continue;
3289                 if (!xfs_iflock_nowait(cip)) {
3290                         xfs_iunlock(cip, XFS_ILOCK_SHARED);
3291                         continue;
3292                 }
3293                 if (xfs_ipincount(cip)) {
3294                         xfs_ifunlock(cip);
3295                         xfs_iunlock(cip, XFS_ILOCK_SHARED);
3296                         continue;
3297                 }
3298 
3299 
3300                 /*
3301                  * Check the inode number again, just to be certain we are not
3302                  * racing with freeing in xfs_reclaim_inode(). See the comments
3303                  * in that function for more information as to why the initial
3304                  * check is not sufficient.
3305                  */
3306                 if (!cip->i_ino) {
3307                         xfs_ifunlock(cip);
3308                         xfs_iunlock(cip, XFS_ILOCK_SHARED);
3309                         continue;
3310                 }
3311 
3312                 /*
3313                  * arriving here means that this inode can be flushed.  First
3314                  * re-check that it's dirty before flushing.
3315                  */
3316                 if (!xfs_inode_clean(cip)) {
3317                         int     error;
3318                         error = xfs_iflush_int(cip, bp);
3319                         if (error) {
3320                                 xfs_iunlock(cip, XFS_ILOCK_SHARED);
3321                                 goto cluster_corrupt_out;
3322                         }
3323                         clcount++;
3324                 } else {
3325                         xfs_ifunlock(cip);
3326                 }
3327                 xfs_iunlock(cip, XFS_ILOCK_SHARED);
3328         }
3329 
3330         if (clcount) {
3331                 XFS_STATS_INC(mp, xs_icluster_flushcnt);
3332                 XFS_STATS_ADD(mp, xs_icluster_flushinode, clcount);
3333         }
3334 
3335 out_free:
3336         rcu_read_unlock();
3337         kmem_free(cilist);
3338 out_put:
3339         xfs_perag_put(pag);
3340         return 0;
3341 
3342 
3343 cluster_corrupt_out:
3344         /*
3345          * Corruption detected in the clustering loop.  Invalidate the
3346          * inode buffer and shut down the filesystem.
3347          */
3348         rcu_read_unlock();
3349         /*
3350          * Clean up the buffer.  If it was delwri, just release it --
3351          * brelse can handle it with no problems.  If not, shut down the
3352          * filesystem before releasing the buffer.
3353          */
3354         bufwasdelwri = (bp->b_flags & _XBF_DELWRI_Q);
3355         if (bufwasdelwri)
3356                 xfs_buf_relse(bp);
3357 
3358         xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3359 
3360         if (!bufwasdelwri) {
3361                 /*
3362                  * Just like incore_relse: if we have b_iodone functions,
3363                  * mark the buffer as an error and call them.  Otherwise
3364                  * mark it as stale and brelse.
3365                  */
3366                 if (bp->b_iodone) {
3367                         bp->b_flags &= ~XBF_DONE;
3368                         xfs_buf_stale(bp);
3369                         xfs_buf_ioerror(bp, -EIO);
3370                         xfs_buf_ioend(bp);
3371                 } else {
3372                         xfs_buf_stale(bp);
3373                         xfs_buf_relse(bp);
3374                 }
3375         }
3376 
3377         /*
3378          * Unlocks the flush lock
3379          */
3380         xfs_iflush_abort(cip, false);
3381         kmem_free(cilist);
3382         xfs_perag_put(pag);
3383         return -EFSCORRUPTED;
3384 }
3385 
3386 /*
3387  * Flush dirty inode metadata into the backing buffer.
3388  *
3389  * The caller must have the inode lock and the inode flush lock held.  The
3390  * inode lock will still be held upon return to the caller, and the inode
3391  * flush lock will be released after the inode has reached the disk.
3392  *
3393  * The caller must write out the buffer returned in *bpp and release it.
3394  */
3395 int
3396 xfs_iflush(
3397         struct xfs_inode        *ip,
3398         struct xfs_buf          **bpp)
3399 {
3400         struct xfs_mount        *mp = ip->i_mount;
3401         struct xfs_buf          *bp = NULL;
3402         struct xfs_dinode       *dip;
3403         int                     error;
3404 
3405         XFS_STATS_INC(mp, xs_iflush_count);
3406 
3407         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3408         ASSERT(xfs_isiflocked(ip));
3409         ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3410                ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3411 
3412         *bpp = NULL;
3413 
3414         xfs_iunpin_wait(ip);
3415 
3416         /*
3417          * For stale inodes we cannot rely on the backing buffer remaining
3418          * stale in cache for the remaining life of the stale inode and so
3419          * xfs_imap_to_bp() below may give us a buffer that no longer contains
3420          * inodes below. We have to check this after ensuring the inode is
3421          * unpinned so that it is safe to reclaim the stale inode after the
3422          * flush call.
3423          */
3424         if (xfs_iflags_test(ip, XFS_ISTALE)) {
3425                 xfs_ifunlock(ip);
3426                 return 0;
3427         }
3428 
3429         /*
3430          * This may have been unpinned because the filesystem is shutting
3431          * down forcibly. If that's the case we must not write this inode
3432          * to disk, because the log record didn't make it to disk.
3433          *
3434          * We also have to remove the log item from the AIL in this case,
3435          * as we wait for an empty AIL as part of the unmount process.
3436          */
3437         if (XFS_FORCED_SHUTDOWN(mp)) {
3438                 error = -EIO;
3439                 goto abort_out;
3440         }
3441 
3442         /*
3443          * Get the buffer containing the on-disk inode. We are doing a try-lock
3444          * operation here, so we may get  an EAGAIN error. In that case, we
3445          * simply want to return with the inode still dirty.
3446          *
3447          * If we get any other error, we effectively have a corruption situation
3448          * and we cannot flush the inode, so we treat it the same as failing
3449          * xfs_iflush_int().
3450          */
3451         error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &dip, &bp, XBF_TRYLOCK,
3452                                0);
3453         if (error == -EAGAIN) {
3454                 xfs_ifunlock(ip);
3455                 return error;
3456         }
3457         if (error)
3458                 goto corrupt_out;
3459 
3460         /*
3461          * First flush out the inode that xfs_iflush was called with.
3462          */
3463         error = xfs_iflush_int(ip, bp);
3464         if (error)
3465                 goto corrupt_out;
3466 
3467         /*
3468          * If the buffer is pinned then push on the log now so we won't
3469          * get stuck waiting in the write for too long.
3470          */
3471         if (xfs_buf_ispinned(bp))
3472                 xfs_log_force(mp, 0);
3473 
3474         /*
3475          * inode clustering:
3476          * see if other inodes can be gathered into this write
3477          */
3478         error = xfs_iflush_cluster(ip, bp);
3479         if (error)
3480                 goto cluster_corrupt_out;
3481 
3482         *bpp = bp;
3483         return 0;
3484 
3485 corrupt_out:
3486         if (bp)
3487                 xfs_buf_relse(bp);
3488         xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
3489 cluster_corrupt_out:
3490         error = -EFSCORRUPTED;
3491 abort_out:
3492         /*
3493          * Unlocks the flush lock
3494          */
3495         xfs_iflush_abort(ip, false);
3496         return error;
3497 }
3498 
3499 /*
3500  * If there are inline format data / attr forks attached to this inode,
3501  * make sure they're not corrupt.
3502  */
3503 bool
3504 xfs_inode_verify_forks(
3505         struct xfs_inode        *ip)
3506 {
3507         struct xfs_ifork        *ifp;
3508         xfs_failaddr_t          fa;
3509 
3510         fa = xfs_ifork_verify_data(ip, &xfs_default_ifork_ops);
3511         if (fa) {
3512                 ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
3513                 xfs_inode_verifier_error(ip, -EFSCORRUPTED, "data fork",
3514                                 ifp->if_u1.if_data, ifp->if_bytes, fa);
3515                 return false;
3516         }
3517 
3518         fa = xfs_ifork_verify_attr(ip, &xfs_default_ifork_ops);
3519         if (fa) {
3520                 ifp = XFS_IFORK_PTR(ip, XFS_ATTR_FORK);
3521                 xfs_inode_verifier_error(ip, -EFSCORRUPTED, "attr fork",
3522                                 ifp ? ifp->if_u1.if_data : NULL,
3523                                 ifp ? ifp->if_bytes : 0, fa);
3524                 return false;
3525         }
3526         return true;
3527 }
3528 
3529 STATIC int
3530 xfs_iflush_int(
3531         struct xfs_inode        *ip,
3532         struct xfs_buf          *bp)
3533 {
3534         struct xfs_inode_log_item *iip = ip->i_itemp;
3535         struct xfs_dinode       *dip;
3536         struct xfs_mount        *mp = ip->i_mount;
3537 
3538         ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
3539         ASSERT(xfs_isiflocked(ip));
3540         ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
3541                ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
3542         ASSERT(iip != NULL && iip->ili_fields != 0);
3543         ASSERT(ip->i_d.di_version > 1);
3544 
3545         /* set *dip = inode's place in the buffer */
3546         dip = xfs_buf_offset(bp, ip->i_imap.im_boffset);
3547 
3548         if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
3549                                mp, XFS_ERRTAG_IFLUSH_1)) {
3550                 xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3551                         "%s: Bad inode %Lu magic number 0x%x, ptr "PTR_FMT,
3552                         __func__, ip->i_ino, be16_to_cpu(dip->di_magic), dip);
3553                 goto corrupt_out;
3554         }
3555         if (S_ISREG(VFS_I(ip)->i_mode)) {
3556                 if (XFS_TEST_ERROR(
3557                     (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3558                     (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
3559                     mp, XFS_ERRTAG_IFLUSH_3)) {
3560                         xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3561                                 "%s: Bad regular inode %Lu, ptr "PTR_FMT,
3562                                 __func__, ip->i_ino, ip);
3563                         goto corrupt_out;
3564                 }
3565         } else if (S_ISDIR(VFS_I(ip)->i_mode)) {
3566                 if (XFS_TEST_ERROR(
3567                     (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
3568                     (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
3569                     (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
3570                     mp, XFS_ERRTAG_IFLUSH_4)) {
3571                         xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3572                                 "%s: Bad directory inode %Lu, ptr "PTR_FMT,
3573                                 __func__, ip->i_ino, ip);
3574                         goto corrupt_out;
3575                 }
3576         }
3577         if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
3578                                 ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5)) {
3579                 xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3580                         "%s: detected corrupt incore inode %Lu, "
3581                         "total extents = %d, nblocks = %Ld, ptr "PTR_FMT,
3582                         __func__, ip->i_ino,
3583                         ip->i_d.di_nextents + ip->i_d.di_anextents,
3584                         ip->i_d.di_nblocks, ip);
3585                 goto corrupt_out;
3586         }
3587         if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
3588                                 mp, XFS_ERRTAG_IFLUSH_6)) {
3589                 xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
3590                         "%s: bad inode %Lu, forkoff 0x%x, ptr "PTR_FMT,
3591                         __func__, ip->i_ino, ip->i_d.di_forkoff, ip);
3592                 goto corrupt_out;
3593         }
3594 
3595         /*
3596          * Inode item log recovery for v2 inodes are dependent on the
3597          * di_flushiter count for correct sequencing. We bump the flush
3598          * iteration count so we can detect flushes which postdate a log record
3599          * during recovery. This is redundant as we now log every change and
3600          * hence this can't happen but we need to still do it to ensure
3601          * backwards compatibility with old kernels that predate logging all
3602          * inode changes.
3603          */
3604         if (ip->i_d.di_version < 3)
3605                 ip->i_d.di_flushiter++;
3606 
3607         /* Check the inline fork data before we write out. */
3608         if (!xfs_inode_verify_forks(ip))
3609                 goto corrupt_out;
3610 
3611         /*
3612          * Copy the dirty parts of the inode into the on-disk inode.  We always
3613          * copy out the core of the inode, because if the inode is dirty at all
3614          * the core must be.
3615          */
3616         xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);
3617 
3618         /* Wrap, we never let the log put out DI_MAX_FLUSH */
3619         if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
3620                 ip->i_d.di_flushiter = 0;
3621 
3622         xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
3623         if (XFS_IFORK_Q(ip))
3624                 xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
3625         xfs_inobp_check(mp, bp);
3626 
3627         /*
3628          * We've recorded everything logged in the inode, so we'd like to clear
3629          * the ili_fields bits so we don't log and flush things unnecessarily.
3630          * However, we can't stop logging all this information until the data
3631          * we've copied into the disk buffer is written to disk.  If we did we
3632          * might overwrite the copy of the inode in the log with all the data
3633          * after re-logging only part of it, and in the face of a crash we
3634          * wouldn't have all the data we need to recover.
3635          *
3636          * What we do is move the bits to the ili_last_fields field.  When
3637          * logging the inode, these bits are moved back to the ili_fields field.
3638          * In the xfs_iflush_done() routine we clear ili_last_fields, since we
3639          * know that the information those bits represent is permanently on
3640          * disk.  As long as the flush completes before the inode is logged
3641          * again, then both ili_fields and ili_last_fields will be cleared.
3642          *
3643          * We can play with the ili_fields bits here, because the inode lock
3644          * must be held exclusively in order to set bits there and the flush
3645          * lock protects the ili_last_fields bits.  Set ili_logged so the flush
3646          * done routine can tell whether or not to look in the AIL.  Also, store
3647          * the current LSN of the inode so that we can tell whether the item has
3648          * moved in the AIL from xfs_iflush_done().  In order to read the lsn we
3649          * need the AIL lock, because it is a 64 bit value that cannot be read
3650          * atomically.
3651          */
3652         iip->ili_last_fields = iip->ili_fields;
3653         iip->ili_fields = 0;
3654         iip->ili_fsync_fields = 0;
3655         iip->ili_logged = 1;
3656 
3657         xfs_trans_ail_copy_lsn(mp->m_ail, &iip->ili_flush_lsn,
3658                                 &iip->ili_item.li_lsn);
3659 
3660         /*
3661          * Attach the function xfs_iflush_done to the inode's
3662          * buffer.  This will remove the inode from the AIL
3663          * and unlock the inode's flush lock when the inode is
3664          * completely written to disk.
3665          */
3666         xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);
3667 
3668         /* generate the checksum. */
3669         xfs_dinode_calc_crc(mp, dip);
3670 
3671         ASSERT(!list_empty(&bp->b_li_list));
3672         ASSERT(bp->b_iodone != NULL);
3673         return 0;
3674 
3675 corrupt_out:
3676         return -EFSCORRUPTED;
3677 }
3678 

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