xref: /openbmc/linux/fs/xfs/xfs_inode_item.c (revision b595076a)
1 /*
2  * Copyright (c) 2000-2002,2005 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 "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_mount.h"
28 #include "xfs_trans_priv.h"
29 #include "xfs_bmap_btree.h"
30 #include "xfs_dinode.h"
31 #include "xfs_inode.h"
32 #include "xfs_inode_item.h"
33 #include "xfs_error.h"
34 #include "xfs_trace.h"
35 
36 
37 kmem_zone_t	*xfs_ili_zone;		/* inode log item zone */
38 
39 static inline struct xfs_inode_log_item *INODE_ITEM(struct xfs_log_item *lip)
40 {
41 	return container_of(lip, struct xfs_inode_log_item, ili_item);
42 }
43 
44 
45 /*
46  * This returns the number of iovecs needed to log the given inode item.
47  *
48  * We need one iovec for the inode log format structure, one for the
49  * inode core, and possibly one for the inode data/extents/b-tree root
50  * and one for the inode attribute data/extents/b-tree root.
51  */
52 STATIC uint
53 xfs_inode_item_size(
54 	struct xfs_log_item	*lip)
55 {
56 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
57 	struct xfs_inode	*ip = iip->ili_inode;
58 	uint			nvecs = 2;
59 
60 	/*
61 	 * Only log the data/extents/b-tree root if there is something
62 	 * left to log.
63 	 */
64 	iip->ili_format.ilf_fields |= XFS_ILOG_CORE;
65 
66 	switch (ip->i_d.di_format) {
67 	case XFS_DINODE_FMT_EXTENTS:
68 		iip->ili_format.ilf_fields &=
69 			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
70 			  XFS_ILOG_DEV | XFS_ILOG_UUID);
71 		if ((iip->ili_format.ilf_fields & XFS_ILOG_DEXT) &&
72 		    (ip->i_d.di_nextents > 0) &&
73 		    (ip->i_df.if_bytes > 0)) {
74 			ASSERT(ip->i_df.if_u1.if_extents != NULL);
75 			nvecs++;
76 		} else {
77 			iip->ili_format.ilf_fields &= ~XFS_ILOG_DEXT;
78 		}
79 		break;
80 
81 	case XFS_DINODE_FMT_BTREE:
82 		ASSERT(ip->i_df.if_ext_max ==
83 		       XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t));
84 		iip->ili_format.ilf_fields &=
85 			~(XFS_ILOG_DDATA | XFS_ILOG_DEXT |
86 			  XFS_ILOG_DEV | XFS_ILOG_UUID);
87 		if ((iip->ili_format.ilf_fields & XFS_ILOG_DBROOT) &&
88 		    (ip->i_df.if_broot_bytes > 0)) {
89 			ASSERT(ip->i_df.if_broot != NULL);
90 			nvecs++;
91 		} else {
92 			ASSERT(!(iip->ili_format.ilf_fields &
93 				 XFS_ILOG_DBROOT));
94 #ifdef XFS_TRANS_DEBUG
95 			if (iip->ili_root_size > 0) {
96 				ASSERT(iip->ili_root_size ==
97 				       ip->i_df.if_broot_bytes);
98 				ASSERT(memcmp(iip->ili_orig_root,
99 					    ip->i_df.if_broot,
100 					    iip->ili_root_size) == 0);
101 			} else {
102 				ASSERT(ip->i_df.if_broot_bytes == 0);
103 			}
104 #endif
105 			iip->ili_format.ilf_fields &= ~XFS_ILOG_DBROOT;
106 		}
107 		break;
108 
109 	case XFS_DINODE_FMT_LOCAL:
110 		iip->ili_format.ilf_fields &=
111 			~(XFS_ILOG_DEXT | XFS_ILOG_DBROOT |
112 			  XFS_ILOG_DEV | XFS_ILOG_UUID);
113 		if ((iip->ili_format.ilf_fields & XFS_ILOG_DDATA) &&
114 		    (ip->i_df.if_bytes > 0)) {
115 			ASSERT(ip->i_df.if_u1.if_data != NULL);
116 			ASSERT(ip->i_d.di_size > 0);
117 			nvecs++;
118 		} else {
119 			iip->ili_format.ilf_fields &= ~XFS_ILOG_DDATA;
120 		}
121 		break;
122 
123 	case XFS_DINODE_FMT_DEV:
124 		iip->ili_format.ilf_fields &=
125 			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
126 			  XFS_ILOG_DEXT | XFS_ILOG_UUID);
127 		break;
128 
129 	case XFS_DINODE_FMT_UUID:
130 		iip->ili_format.ilf_fields &=
131 			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
132 			  XFS_ILOG_DEXT | XFS_ILOG_DEV);
133 		break;
134 
135 	default:
136 		ASSERT(0);
137 		break;
138 	}
139 
140 	/*
141 	 * If there are no attributes associated with this file,
142 	 * then there cannot be anything more to log.
143 	 * Clear all attribute-related log flags.
144 	 */
145 	if (!XFS_IFORK_Q(ip)) {
146 		iip->ili_format.ilf_fields &=
147 			~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT);
148 		return nvecs;
149 	}
150 
151 	/*
152 	 * Log any necessary attribute data.
153 	 */
154 	switch (ip->i_d.di_aformat) {
155 	case XFS_DINODE_FMT_EXTENTS:
156 		iip->ili_format.ilf_fields &=
157 			~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT);
158 		if ((iip->ili_format.ilf_fields & XFS_ILOG_AEXT) &&
159 		    (ip->i_d.di_anextents > 0) &&
160 		    (ip->i_afp->if_bytes > 0)) {
161 			ASSERT(ip->i_afp->if_u1.if_extents != NULL);
162 			nvecs++;
163 		} else {
164 			iip->ili_format.ilf_fields &= ~XFS_ILOG_AEXT;
165 		}
166 		break;
167 
168 	case XFS_DINODE_FMT_BTREE:
169 		iip->ili_format.ilf_fields &=
170 			~(XFS_ILOG_ADATA | XFS_ILOG_AEXT);
171 		if ((iip->ili_format.ilf_fields & XFS_ILOG_ABROOT) &&
172 		    (ip->i_afp->if_broot_bytes > 0)) {
173 			ASSERT(ip->i_afp->if_broot != NULL);
174 			nvecs++;
175 		} else {
176 			iip->ili_format.ilf_fields &= ~XFS_ILOG_ABROOT;
177 		}
178 		break;
179 
180 	case XFS_DINODE_FMT_LOCAL:
181 		iip->ili_format.ilf_fields &=
182 			~(XFS_ILOG_AEXT | XFS_ILOG_ABROOT);
183 		if ((iip->ili_format.ilf_fields & XFS_ILOG_ADATA) &&
184 		    (ip->i_afp->if_bytes > 0)) {
185 			ASSERT(ip->i_afp->if_u1.if_data != NULL);
186 			nvecs++;
187 		} else {
188 			iip->ili_format.ilf_fields &= ~XFS_ILOG_ADATA;
189 		}
190 		break;
191 
192 	default:
193 		ASSERT(0);
194 		break;
195 	}
196 
197 	return nvecs;
198 }
199 
200 /*
201  * This is called to fill in the vector of log iovecs for the
202  * given inode log item.  It fills the first item with an inode
203  * log format structure, the second with the on-disk inode structure,
204  * and a possible third and/or fourth with the inode data/extents/b-tree
205  * root and inode attributes data/extents/b-tree root.
206  */
207 STATIC void
208 xfs_inode_item_format(
209 	struct xfs_log_item	*lip,
210 	struct xfs_log_iovec	*vecp)
211 {
212 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
213 	struct xfs_inode	*ip = iip->ili_inode;
214 	uint			nvecs;
215 	size_t			data_bytes;
216 	xfs_bmbt_rec_t		*ext_buffer;
217 	xfs_mount_t		*mp;
218 
219 	vecp->i_addr = &iip->ili_format;
220 	vecp->i_len  = sizeof(xfs_inode_log_format_t);
221 	vecp->i_type = XLOG_REG_TYPE_IFORMAT;
222 	vecp++;
223 	nvecs	     = 1;
224 
225 	/*
226 	 * Clear i_update_core if the timestamps (or any other
227 	 * non-transactional modification) need flushing/logging
228 	 * and we're about to log them with the rest of the core.
229 	 *
230 	 * This is the same logic as xfs_iflush() but this code can't
231 	 * run at the same time as xfs_iflush because we're in commit
232 	 * processing here and so we have the inode lock held in
233 	 * exclusive mode.  Although it doesn't really matter
234 	 * for the timestamps if both routines were to grab the
235 	 * timestamps or not.  That would be ok.
236 	 *
237 	 * We clear i_update_core before copying out the data.
238 	 * This is for coordination with our timestamp updates
239 	 * that don't hold the inode lock. They will always
240 	 * update the timestamps BEFORE setting i_update_core,
241 	 * so if we clear i_update_core after they set it we
242 	 * are guaranteed to see their updates to the timestamps
243 	 * either here.  Likewise, if they set it after we clear it
244 	 * here, we'll see it either on the next commit of this
245 	 * inode or the next time the inode gets flushed via
246 	 * xfs_iflush().  This depends on strongly ordered memory
247 	 * semantics, but we have that.  We use the SYNCHRONIZE
248 	 * macro to make sure that the compiler does not reorder
249 	 * the i_update_core access below the data copy below.
250 	 */
251 	if (ip->i_update_core)  {
252 		ip->i_update_core = 0;
253 		SYNCHRONIZE();
254 	}
255 
256 	/*
257 	 * Make sure to get the latest timestamps from the Linux inode.
258 	 */
259 	xfs_synchronize_times(ip);
260 
261 	vecp->i_addr = &ip->i_d;
262 	vecp->i_len  = sizeof(struct xfs_icdinode);
263 	vecp->i_type = XLOG_REG_TYPE_ICORE;
264 	vecp++;
265 	nvecs++;
266 	iip->ili_format.ilf_fields |= XFS_ILOG_CORE;
267 
268 	/*
269 	 * If this is really an old format inode, then we need to
270 	 * log it as such.  This means that we have to copy the link
271 	 * count from the new field to the old.  We don't have to worry
272 	 * about the new fields, because nothing trusts them as long as
273 	 * the old inode version number is there.  If the superblock already
274 	 * has a new version number, then we don't bother converting back.
275 	 */
276 	mp = ip->i_mount;
277 	ASSERT(ip->i_d.di_version == 1 || xfs_sb_version_hasnlink(&mp->m_sb));
278 	if (ip->i_d.di_version == 1) {
279 		if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
280 			/*
281 			 * Convert it back.
282 			 */
283 			ASSERT(ip->i_d.di_nlink <= XFS_MAXLINK_1);
284 			ip->i_d.di_onlink = ip->i_d.di_nlink;
285 		} else {
286 			/*
287 			 * The superblock version has already been bumped,
288 			 * so just make the conversion to the new inode
289 			 * format permanent.
290 			 */
291 			ip->i_d.di_version = 2;
292 			ip->i_d.di_onlink = 0;
293 			memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
294 		}
295 	}
296 
297 	switch (ip->i_d.di_format) {
298 	case XFS_DINODE_FMT_EXTENTS:
299 		ASSERT(!(iip->ili_format.ilf_fields &
300 			 (XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
301 			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
302 		if (iip->ili_format.ilf_fields & XFS_ILOG_DEXT) {
303 			ASSERT(ip->i_df.if_bytes > 0);
304 			ASSERT(ip->i_df.if_u1.if_extents != NULL);
305 			ASSERT(ip->i_d.di_nextents > 0);
306 			ASSERT(iip->ili_extents_buf == NULL);
307 			ASSERT((ip->i_df.if_bytes /
308 				(uint)sizeof(xfs_bmbt_rec_t)) > 0);
309 #ifdef XFS_NATIVE_HOST
310                        if (ip->i_d.di_nextents == ip->i_df.if_bytes /
311                                                (uint)sizeof(xfs_bmbt_rec_t)) {
312 				/*
313 				 * There are no delayed allocation
314 				 * extents, so just point to the
315 				 * real extents array.
316 				 */
317 				vecp->i_addr = ip->i_df.if_u1.if_extents;
318 				vecp->i_len = ip->i_df.if_bytes;
319 				vecp->i_type = XLOG_REG_TYPE_IEXT;
320 			} else
321 #endif
322 			{
323 				/*
324 				 * There are delayed allocation extents
325 				 * in the inode, or we need to convert
326 				 * the extents to on disk format.
327 				 * Use xfs_iextents_copy()
328 				 * to copy only the real extents into
329 				 * a separate buffer.  We'll free the
330 				 * buffer in the unlock routine.
331 				 */
332 				ext_buffer = kmem_alloc(ip->i_df.if_bytes,
333 					KM_SLEEP);
334 				iip->ili_extents_buf = ext_buffer;
335 				vecp->i_addr = ext_buffer;
336 				vecp->i_len = xfs_iextents_copy(ip, ext_buffer,
337 						XFS_DATA_FORK);
338 				vecp->i_type = XLOG_REG_TYPE_IEXT;
339 			}
340 			ASSERT(vecp->i_len <= ip->i_df.if_bytes);
341 			iip->ili_format.ilf_dsize = vecp->i_len;
342 			vecp++;
343 			nvecs++;
344 		}
345 		break;
346 
347 	case XFS_DINODE_FMT_BTREE:
348 		ASSERT(!(iip->ili_format.ilf_fields &
349 			 (XFS_ILOG_DDATA | XFS_ILOG_DEXT |
350 			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
351 		if (iip->ili_format.ilf_fields & XFS_ILOG_DBROOT) {
352 			ASSERT(ip->i_df.if_broot_bytes > 0);
353 			ASSERT(ip->i_df.if_broot != NULL);
354 			vecp->i_addr = ip->i_df.if_broot;
355 			vecp->i_len = ip->i_df.if_broot_bytes;
356 			vecp->i_type = XLOG_REG_TYPE_IBROOT;
357 			vecp++;
358 			nvecs++;
359 			iip->ili_format.ilf_dsize = ip->i_df.if_broot_bytes;
360 		}
361 		break;
362 
363 	case XFS_DINODE_FMT_LOCAL:
364 		ASSERT(!(iip->ili_format.ilf_fields &
365 			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
366 			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
367 		if (iip->ili_format.ilf_fields & XFS_ILOG_DDATA) {
368 			ASSERT(ip->i_df.if_bytes > 0);
369 			ASSERT(ip->i_df.if_u1.if_data != NULL);
370 			ASSERT(ip->i_d.di_size > 0);
371 
372 			vecp->i_addr = ip->i_df.if_u1.if_data;
373 			/*
374 			 * Round i_bytes up to a word boundary.
375 			 * The underlying memory is guaranteed to
376 			 * to be there by xfs_idata_realloc().
377 			 */
378 			data_bytes = roundup(ip->i_df.if_bytes, 4);
379 			ASSERT((ip->i_df.if_real_bytes == 0) ||
380 			       (ip->i_df.if_real_bytes == data_bytes));
381 			vecp->i_len = (int)data_bytes;
382 			vecp->i_type = XLOG_REG_TYPE_ILOCAL;
383 			vecp++;
384 			nvecs++;
385 			iip->ili_format.ilf_dsize = (unsigned)data_bytes;
386 		}
387 		break;
388 
389 	case XFS_DINODE_FMT_DEV:
390 		ASSERT(!(iip->ili_format.ilf_fields &
391 			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
392 			  XFS_ILOG_DDATA | XFS_ILOG_UUID)));
393 		if (iip->ili_format.ilf_fields & XFS_ILOG_DEV) {
394 			iip->ili_format.ilf_u.ilfu_rdev =
395 				ip->i_df.if_u2.if_rdev;
396 		}
397 		break;
398 
399 	case XFS_DINODE_FMT_UUID:
400 		ASSERT(!(iip->ili_format.ilf_fields &
401 			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
402 			  XFS_ILOG_DDATA | XFS_ILOG_DEV)));
403 		if (iip->ili_format.ilf_fields & XFS_ILOG_UUID) {
404 			iip->ili_format.ilf_u.ilfu_uuid =
405 				ip->i_df.if_u2.if_uuid;
406 		}
407 		break;
408 
409 	default:
410 		ASSERT(0);
411 		break;
412 	}
413 
414 	/*
415 	 * If there are no attributes associated with the file,
416 	 * then we're done.
417 	 * Assert that no attribute-related log flags are set.
418 	 */
419 	if (!XFS_IFORK_Q(ip)) {
420 		ASSERT(nvecs == lip->li_desc->lid_size);
421 		iip->ili_format.ilf_size = nvecs;
422 		ASSERT(!(iip->ili_format.ilf_fields &
423 			 (XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT)));
424 		return;
425 	}
426 
427 	switch (ip->i_d.di_aformat) {
428 	case XFS_DINODE_FMT_EXTENTS:
429 		ASSERT(!(iip->ili_format.ilf_fields &
430 			 (XFS_ILOG_ADATA | XFS_ILOG_ABROOT)));
431 		if (iip->ili_format.ilf_fields & XFS_ILOG_AEXT) {
432 #ifdef DEBUG
433 			int nrecs = ip->i_afp->if_bytes /
434 				(uint)sizeof(xfs_bmbt_rec_t);
435 			ASSERT(nrecs > 0);
436 			ASSERT(nrecs == ip->i_d.di_anextents);
437 			ASSERT(ip->i_afp->if_bytes > 0);
438 			ASSERT(ip->i_afp->if_u1.if_extents != NULL);
439 			ASSERT(ip->i_d.di_anextents > 0);
440 #endif
441 #ifdef XFS_NATIVE_HOST
442 			/*
443 			 * There are not delayed allocation extents
444 			 * for attributes, so just point at the array.
445 			 */
446 			vecp->i_addr = ip->i_afp->if_u1.if_extents;
447 			vecp->i_len = ip->i_afp->if_bytes;
448 #else
449 			ASSERT(iip->ili_aextents_buf == NULL);
450 			/*
451 			 * Need to endian flip before logging
452 			 */
453 			ext_buffer = kmem_alloc(ip->i_afp->if_bytes,
454 				KM_SLEEP);
455 			iip->ili_aextents_buf = ext_buffer;
456 			vecp->i_addr = ext_buffer;
457 			vecp->i_len = xfs_iextents_copy(ip, ext_buffer,
458 					XFS_ATTR_FORK);
459 #endif
460 			vecp->i_type = XLOG_REG_TYPE_IATTR_EXT;
461 			iip->ili_format.ilf_asize = vecp->i_len;
462 			vecp++;
463 			nvecs++;
464 		}
465 		break;
466 
467 	case XFS_DINODE_FMT_BTREE:
468 		ASSERT(!(iip->ili_format.ilf_fields &
469 			 (XFS_ILOG_ADATA | XFS_ILOG_AEXT)));
470 		if (iip->ili_format.ilf_fields & XFS_ILOG_ABROOT) {
471 			ASSERT(ip->i_afp->if_broot_bytes > 0);
472 			ASSERT(ip->i_afp->if_broot != NULL);
473 			vecp->i_addr = ip->i_afp->if_broot;
474 			vecp->i_len = ip->i_afp->if_broot_bytes;
475 			vecp->i_type = XLOG_REG_TYPE_IATTR_BROOT;
476 			vecp++;
477 			nvecs++;
478 			iip->ili_format.ilf_asize = ip->i_afp->if_broot_bytes;
479 		}
480 		break;
481 
482 	case XFS_DINODE_FMT_LOCAL:
483 		ASSERT(!(iip->ili_format.ilf_fields &
484 			 (XFS_ILOG_ABROOT | XFS_ILOG_AEXT)));
485 		if (iip->ili_format.ilf_fields & XFS_ILOG_ADATA) {
486 			ASSERT(ip->i_afp->if_bytes > 0);
487 			ASSERT(ip->i_afp->if_u1.if_data != NULL);
488 
489 			vecp->i_addr = ip->i_afp->if_u1.if_data;
490 			/*
491 			 * Round i_bytes up to a word boundary.
492 			 * The underlying memory is guaranteed to
493 			 * to be there by xfs_idata_realloc().
494 			 */
495 			data_bytes = roundup(ip->i_afp->if_bytes, 4);
496 			ASSERT((ip->i_afp->if_real_bytes == 0) ||
497 			       (ip->i_afp->if_real_bytes == data_bytes));
498 			vecp->i_len = (int)data_bytes;
499 			vecp->i_type = XLOG_REG_TYPE_IATTR_LOCAL;
500 			vecp++;
501 			nvecs++;
502 			iip->ili_format.ilf_asize = (unsigned)data_bytes;
503 		}
504 		break;
505 
506 	default:
507 		ASSERT(0);
508 		break;
509 	}
510 
511 	ASSERT(nvecs == lip->li_desc->lid_size);
512 	iip->ili_format.ilf_size = nvecs;
513 }
514 
515 
516 /*
517  * This is called to pin the inode associated with the inode log
518  * item in memory so it cannot be written out.
519  */
520 STATIC void
521 xfs_inode_item_pin(
522 	struct xfs_log_item	*lip)
523 {
524 	struct xfs_inode	*ip = INODE_ITEM(lip)->ili_inode;
525 
526 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
527 
528 	trace_xfs_inode_pin(ip, _RET_IP_);
529 	atomic_inc(&ip->i_pincount);
530 }
531 
532 
533 /*
534  * This is called to unpin the inode associated with the inode log
535  * item which was previously pinned with a call to xfs_inode_item_pin().
536  *
537  * Also wake up anyone in xfs_iunpin_wait() if the count goes to 0.
538  */
539 STATIC void
540 xfs_inode_item_unpin(
541 	struct xfs_log_item	*lip,
542 	int			remove)
543 {
544 	struct xfs_inode	*ip = INODE_ITEM(lip)->ili_inode;
545 
546 	trace_xfs_inode_unpin(ip, _RET_IP_);
547 	ASSERT(atomic_read(&ip->i_pincount) > 0);
548 	if (atomic_dec_and_test(&ip->i_pincount))
549 		wake_up(&ip->i_ipin_wait);
550 }
551 
552 /*
553  * This is called to attempt to lock the inode associated with this
554  * inode log item, in preparation for the push routine which does the actual
555  * iflush.  Don't sleep on the inode lock or the flush lock.
556  *
557  * If the flush lock is already held, indicating that the inode has
558  * been or is in the process of being flushed, then (ideally) we'd like to
559  * see if the inode's buffer is still incore, and if so give it a nudge.
560  * We delay doing so until the pushbuf routine, though, to avoid holding
561  * the AIL lock across a call to the blackhole which is the buffer cache.
562  * Also we don't want to sleep in any device strategy routines, which can happen
563  * if we do the subsequent bawrite in here.
564  */
565 STATIC uint
566 xfs_inode_item_trylock(
567 	struct xfs_log_item	*lip)
568 {
569 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
570 	struct xfs_inode	*ip = iip->ili_inode;
571 
572 	if (xfs_ipincount(ip) > 0)
573 		return XFS_ITEM_PINNED;
574 
575 	if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED))
576 		return XFS_ITEM_LOCKED;
577 
578 	if (!xfs_iflock_nowait(ip)) {
579 		/*
580 		 * inode has already been flushed to the backing buffer,
581 		 * leave it locked in shared mode, pushbuf routine will
582 		 * unlock it.
583 		 */
584 		return XFS_ITEM_PUSHBUF;
585 	}
586 
587 	/* Stale items should force out the iclog */
588 	if (ip->i_flags & XFS_ISTALE) {
589 		xfs_ifunlock(ip);
590 		/*
591 		 * we hold the AIL lock - notify the unlock routine of this
592 		 * so it doesn't try to get the lock again.
593 		 */
594 		xfs_iunlock(ip, XFS_ILOCK_SHARED|XFS_IUNLOCK_NONOTIFY);
595 		return XFS_ITEM_PINNED;
596 	}
597 
598 #ifdef DEBUG
599 	if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
600 		ASSERT(iip->ili_format.ilf_fields != 0);
601 		ASSERT(iip->ili_logged == 0);
602 		ASSERT(lip->li_flags & XFS_LI_IN_AIL);
603 	}
604 #endif
605 	return XFS_ITEM_SUCCESS;
606 }
607 
608 /*
609  * Unlock the inode associated with the inode log item.
610  * Clear the fields of the inode and inode log item that
611  * are specific to the current transaction.  If the
612  * hold flags is set, do not unlock the inode.
613  */
614 STATIC void
615 xfs_inode_item_unlock(
616 	struct xfs_log_item	*lip)
617 {
618 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
619 	struct xfs_inode	*ip = iip->ili_inode;
620 	unsigned short		lock_flags;
621 
622 	ASSERT(iip->ili_inode->i_itemp != NULL);
623 	ASSERT(xfs_isilocked(iip->ili_inode, XFS_ILOCK_EXCL));
624 
625 	/*
626 	 * Clear the transaction pointer in the inode.
627 	 */
628 	ip->i_transp = NULL;
629 
630 	/*
631 	 * If the inode needed a separate buffer with which to log
632 	 * its extents, then free it now.
633 	 */
634 	if (iip->ili_extents_buf != NULL) {
635 		ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS);
636 		ASSERT(ip->i_d.di_nextents > 0);
637 		ASSERT(iip->ili_format.ilf_fields & XFS_ILOG_DEXT);
638 		ASSERT(ip->i_df.if_bytes > 0);
639 		kmem_free(iip->ili_extents_buf);
640 		iip->ili_extents_buf = NULL;
641 	}
642 	if (iip->ili_aextents_buf != NULL) {
643 		ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS);
644 		ASSERT(ip->i_d.di_anextents > 0);
645 		ASSERT(iip->ili_format.ilf_fields & XFS_ILOG_AEXT);
646 		ASSERT(ip->i_afp->if_bytes > 0);
647 		kmem_free(iip->ili_aextents_buf);
648 		iip->ili_aextents_buf = NULL;
649 	}
650 
651 	lock_flags = iip->ili_lock_flags;
652 	iip->ili_lock_flags = 0;
653 	if (lock_flags) {
654 		xfs_iunlock(iip->ili_inode, lock_flags);
655 		IRELE(iip->ili_inode);
656 	}
657 }
658 
659 /*
660  * This is called to find out where the oldest active copy of the
661  * inode log item in the on disk log resides now that the last log
662  * write of it completed at the given lsn.  Since we always re-log
663  * all dirty data in an inode, the latest copy in the on disk log
664  * is the only one that matters.  Therefore, simply return the
665  * given lsn.
666  */
667 STATIC xfs_lsn_t
668 xfs_inode_item_committed(
669 	struct xfs_log_item	*lip,
670 	xfs_lsn_t		lsn)
671 {
672 	return lsn;
673 }
674 
675 /*
676  * This gets called by xfs_trans_push_ail(), when IOP_TRYLOCK
677  * failed to get the inode flush lock but did get the inode locked SHARED.
678  * Here we're trying to see if the inode buffer is incore, and if so whether it's
679  * marked delayed write. If that's the case, we'll promote it and that will
680  * allow the caller to write the buffer by triggering the xfsbufd to run.
681  */
682 STATIC void
683 xfs_inode_item_pushbuf(
684 	struct xfs_log_item	*lip)
685 {
686 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
687 	struct xfs_inode	*ip = iip->ili_inode;
688 	struct xfs_buf		*bp;
689 
690 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));
691 
692 	/*
693 	 * If a flush is not in progress anymore, chances are that the
694 	 * inode was taken off the AIL. So, just get out.
695 	 */
696 	if (completion_done(&ip->i_flush) ||
697 	    !(lip->li_flags & XFS_LI_IN_AIL)) {
698 		xfs_iunlock(ip, XFS_ILOCK_SHARED);
699 		return;
700 	}
701 
702 	bp = xfs_incore(ip->i_mount->m_ddev_targp, iip->ili_format.ilf_blkno,
703 			iip->ili_format.ilf_len, XBF_TRYLOCK);
704 
705 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
706 	if (!bp)
707 		return;
708 	if (XFS_BUF_ISDELAYWRITE(bp))
709 		xfs_buf_delwri_promote(bp);
710 	xfs_buf_relse(bp);
711 }
712 
713 /*
714  * This is called to asynchronously write the inode associated with this
715  * inode log item out to disk. The inode will already have been locked by
716  * a successful call to xfs_inode_item_trylock().
717  */
718 STATIC void
719 xfs_inode_item_push(
720 	struct xfs_log_item	*lip)
721 {
722 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
723 	struct xfs_inode	*ip = iip->ili_inode;
724 
725 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));
726 	ASSERT(!completion_done(&ip->i_flush));
727 
728 	/*
729 	 * Since we were able to lock the inode's flush lock and
730 	 * we found it on the AIL, the inode must be dirty.  This
731 	 * is because the inode is removed from the AIL while still
732 	 * holding the flush lock in xfs_iflush_done().  Thus, if
733 	 * we found it in the AIL and were able to obtain the flush
734 	 * lock without sleeping, then there must not have been
735 	 * anyone in the process of flushing the inode.
736 	 */
737 	ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) ||
738 	       iip->ili_format.ilf_fields != 0);
739 
740 	/*
741 	 * Push the inode to it's backing buffer. This will not remove the
742 	 * inode from the AIL - a further push will be required to trigger a
743 	 * buffer push. However, this allows all the dirty inodes to be pushed
744 	 * to the buffer before it is pushed to disk. THe buffer IO completion
745 	 * will pull th einode from the AIL, mark it clean and unlock the flush
746 	 * lock.
747 	 */
748 	(void) xfs_iflush(ip, 0);
749 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
750 }
751 
752 /*
753  * XXX rcc - this one really has to do something.  Probably needs
754  * to stamp in a new field in the incore inode.
755  */
756 STATIC void
757 xfs_inode_item_committing(
758 	struct xfs_log_item	*lip,
759 	xfs_lsn_t		lsn)
760 {
761 	INODE_ITEM(lip)->ili_last_lsn = lsn;
762 }
763 
764 /*
765  * This is the ops vector shared by all buf log items.
766  */
767 static struct xfs_item_ops xfs_inode_item_ops = {
768 	.iop_size	= xfs_inode_item_size,
769 	.iop_format	= xfs_inode_item_format,
770 	.iop_pin	= xfs_inode_item_pin,
771 	.iop_unpin	= xfs_inode_item_unpin,
772 	.iop_trylock	= xfs_inode_item_trylock,
773 	.iop_unlock	= xfs_inode_item_unlock,
774 	.iop_committed	= xfs_inode_item_committed,
775 	.iop_push	= xfs_inode_item_push,
776 	.iop_pushbuf	= xfs_inode_item_pushbuf,
777 	.iop_committing = xfs_inode_item_committing
778 };
779 
780 
781 /*
782  * Initialize the inode log item for a newly allocated (in-core) inode.
783  */
784 void
785 xfs_inode_item_init(
786 	struct xfs_inode	*ip,
787 	struct xfs_mount	*mp)
788 {
789 	struct xfs_inode_log_item *iip;
790 
791 	ASSERT(ip->i_itemp == NULL);
792 	iip = ip->i_itemp = kmem_zone_zalloc(xfs_ili_zone, KM_SLEEP);
793 
794 	iip->ili_inode = ip;
795 	xfs_log_item_init(mp, &iip->ili_item, XFS_LI_INODE,
796 						&xfs_inode_item_ops);
797 	iip->ili_format.ilf_type = XFS_LI_INODE;
798 	iip->ili_format.ilf_ino = ip->i_ino;
799 	iip->ili_format.ilf_blkno = ip->i_imap.im_blkno;
800 	iip->ili_format.ilf_len = ip->i_imap.im_len;
801 	iip->ili_format.ilf_boffset = ip->i_imap.im_boffset;
802 }
803 
804 /*
805  * Free the inode log item and any memory hanging off of it.
806  */
807 void
808 xfs_inode_item_destroy(
809 	xfs_inode_t	*ip)
810 {
811 #ifdef XFS_TRANS_DEBUG
812 	if (ip->i_itemp->ili_root_size != 0) {
813 		kmem_free(ip->i_itemp->ili_orig_root);
814 	}
815 #endif
816 	kmem_zone_free(xfs_ili_zone, ip->i_itemp);
817 }
818 
819 
820 /*
821  * This is the inode flushing I/O completion routine.  It is called
822  * from interrupt level when the buffer containing the inode is
823  * flushed to disk.  It is responsible for removing the inode item
824  * from the AIL if it has not been re-logged, and unlocking the inode's
825  * flush lock.
826  */
827 void
828 xfs_iflush_done(
829 	struct xfs_buf		*bp,
830 	struct xfs_log_item	*lip)
831 {
832 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
833 	xfs_inode_t		*ip = iip->ili_inode;
834 	struct xfs_ail		*ailp = lip->li_ailp;
835 
836 	/*
837 	 * We only want to pull the item from the AIL if it is
838 	 * actually there and its location in the log has not
839 	 * changed since we started the flush.  Thus, we only bother
840 	 * if the ili_logged flag is set and the inode's lsn has not
841 	 * changed.  First we check the lsn outside
842 	 * the lock since it's cheaper, and then we recheck while
843 	 * holding the lock before removing the inode from the AIL.
844 	 */
845 	if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) {
846 		spin_lock(&ailp->xa_lock);
847 		if (lip->li_lsn == iip->ili_flush_lsn) {
848 			/* xfs_trans_ail_delete() drops the AIL lock. */
849 			xfs_trans_ail_delete(ailp, lip);
850 		} else {
851 			spin_unlock(&ailp->xa_lock);
852 		}
853 	}
854 
855 	iip->ili_logged = 0;
856 
857 	/*
858 	 * Clear the ili_last_fields bits now that we know that the
859 	 * data corresponding to them is safely on disk.
860 	 */
861 	iip->ili_last_fields = 0;
862 
863 	/*
864 	 * Release the inode's flush lock since we're done with it.
865 	 */
866 	xfs_ifunlock(ip);
867 }
868 
869 /*
870  * This is the inode flushing abort routine.  It is called
871  * from xfs_iflush when the filesystem is shutting down to clean
872  * up the inode state.
873  * It is responsible for removing the inode item
874  * from the AIL if it has not been re-logged, and unlocking the inode's
875  * flush lock.
876  */
877 void
878 xfs_iflush_abort(
879 	xfs_inode_t		*ip)
880 {
881 	xfs_inode_log_item_t	*iip = ip->i_itemp;
882 
883 	iip = ip->i_itemp;
884 	if (iip) {
885 		struct xfs_ail	*ailp = iip->ili_item.li_ailp;
886 		if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {
887 			spin_lock(&ailp->xa_lock);
888 			if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {
889 				/* xfs_trans_ail_delete() drops the AIL lock. */
890 				xfs_trans_ail_delete(ailp, (xfs_log_item_t *)iip);
891 			} else
892 				spin_unlock(&ailp->xa_lock);
893 		}
894 		iip->ili_logged = 0;
895 		/*
896 		 * Clear the ili_last_fields bits now that we know that the
897 		 * data corresponding to them is safely on disk.
898 		 */
899 		iip->ili_last_fields = 0;
900 		/*
901 		 * Clear the inode logging fields so no more flushes are
902 		 * attempted.
903 		 */
904 		iip->ili_format.ilf_fields = 0;
905 	}
906 	/*
907 	 * Release the inode's flush lock since we're done with it.
908 	 */
909 	xfs_ifunlock(ip);
910 }
911 
912 void
913 xfs_istale_done(
914 	struct xfs_buf		*bp,
915 	struct xfs_log_item	*lip)
916 {
917 	xfs_iflush_abort(INODE_ITEM(lip)->ili_inode);
918 }
919 
920 /*
921  * convert an xfs_inode_log_format struct from either 32 or 64 bit versions
922  * (which can have different field alignments) to the native version
923  */
924 int
925 xfs_inode_item_format_convert(
926 	xfs_log_iovec_t		*buf,
927 	xfs_inode_log_format_t	*in_f)
928 {
929 	if (buf->i_len == sizeof(xfs_inode_log_format_32_t)) {
930 		xfs_inode_log_format_32_t *in_f32 = buf->i_addr;
931 
932 		in_f->ilf_type = in_f32->ilf_type;
933 		in_f->ilf_size = in_f32->ilf_size;
934 		in_f->ilf_fields = in_f32->ilf_fields;
935 		in_f->ilf_asize = in_f32->ilf_asize;
936 		in_f->ilf_dsize = in_f32->ilf_dsize;
937 		in_f->ilf_ino = in_f32->ilf_ino;
938 		/* copy biggest field of ilf_u */
939 		memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
940 		       in_f32->ilf_u.ilfu_uuid.__u_bits,
941 		       sizeof(uuid_t));
942 		in_f->ilf_blkno = in_f32->ilf_blkno;
943 		in_f->ilf_len = in_f32->ilf_len;
944 		in_f->ilf_boffset = in_f32->ilf_boffset;
945 		return 0;
946 	} else if (buf->i_len == sizeof(xfs_inode_log_format_64_t)){
947 		xfs_inode_log_format_64_t *in_f64 = buf->i_addr;
948 
949 		in_f->ilf_type = in_f64->ilf_type;
950 		in_f->ilf_size = in_f64->ilf_size;
951 		in_f->ilf_fields = in_f64->ilf_fields;
952 		in_f->ilf_asize = in_f64->ilf_asize;
953 		in_f->ilf_dsize = in_f64->ilf_dsize;
954 		in_f->ilf_ino = in_f64->ilf_ino;
955 		/* copy biggest field of ilf_u */
956 		memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
957 		       in_f64->ilf_u.ilfu_uuid.__u_bits,
958 		       sizeof(uuid_t));
959 		in_f->ilf_blkno = in_f64->ilf_blkno;
960 		in_f->ilf_len = in_f64->ilf_len;
961 		in_f->ilf_boffset = in_f64->ilf_boffset;
962 		return 0;
963 	}
964 	return EFSCORRUPTED;
965 }
966