xref: /openbmc/linux/fs/xfs/xfs_inode_item.c (revision 61a3e166)
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 	 * Make sure the linux inode is dirty. We do this before
227 	 * clearing i_update_core as the VFS will call back into
228 	 * XFS here and set i_update_core, so we need to dirty the
229 	 * inode first so that the ordering of i_update_core and
230 	 * unlogged modifications still works as described below.
231 	 */
232 	xfs_mark_inode_dirty_sync(ip);
233 
234 	/*
235 	 * Clear i_update_core if the timestamps (or any other
236 	 * non-transactional modification) need flushing/logging
237 	 * and we're about to log them with the rest of the core.
238 	 *
239 	 * This is the same logic as xfs_iflush() but this code can't
240 	 * run at the same time as xfs_iflush because we're in commit
241 	 * processing here and so we have the inode lock held in
242 	 * exclusive mode.  Although it doesn't really matter
243 	 * for the timestamps if both routines were to grab the
244 	 * timestamps or not.  That would be ok.
245 	 *
246 	 * We clear i_update_core before copying out the data.
247 	 * This is for coordination with our timestamp updates
248 	 * that don't hold the inode lock. They will always
249 	 * update the timestamps BEFORE setting i_update_core,
250 	 * so if we clear i_update_core after they set it we
251 	 * are guaranteed to see their updates to the timestamps
252 	 * either here.  Likewise, if they set it after we clear it
253 	 * here, we'll see it either on the next commit of this
254 	 * inode or the next time the inode gets flushed via
255 	 * xfs_iflush().  This depends on strongly ordered memory
256 	 * semantics, but we have that.  We use the SYNCHRONIZE
257 	 * macro to make sure that the compiler does not reorder
258 	 * the i_update_core access below the data copy below.
259 	 */
260 	if (ip->i_update_core)  {
261 		ip->i_update_core = 0;
262 		SYNCHRONIZE();
263 	}
264 
265 	/*
266 	 * Make sure to get the latest timestamps from the Linux inode.
267 	 */
268 	xfs_synchronize_times(ip);
269 
270 	vecp->i_addr = &ip->i_d;
271 	vecp->i_len  = sizeof(struct xfs_icdinode);
272 	vecp->i_type = XLOG_REG_TYPE_ICORE;
273 	vecp++;
274 	nvecs++;
275 	iip->ili_format.ilf_fields |= XFS_ILOG_CORE;
276 
277 	/*
278 	 * If this is really an old format inode, then we need to
279 	 * log it as such.  This means that we have to copy the link
280 	 * count from the new field to the old.  We don't have to worry
281 	 * about the new fields, because nothing trusts them as long as
282 	 * the old inode version number is there.  If the superblock already
283 	 * has a new version number, then we don't bother converting back.
284 	 */
285 	mp = ip->i_mount;
286 	ASSERT(ip->i_d.di_version == 1 || xfs_sb_version_hasnlink(&mp->m_sb));
287 	if (ip->i_d.di_version == 1) {
288 		if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
289 			/*
290 			 * Convert it back.
291 			 */
292 			ASSERT(ip->i_d.di_nlink <= XFS_MAXLINK_1);
293 			ip->i_d.di_onlink = ip->i_d.di_nlink;
294 		} else {
295 			/*
296 			 * The superblock version has already been bumped,
297 			 * so just make the conversion to the new inode
298 			 * format permanent.
299 			 */
300 			ip->i_d.di_version = 2;
301 			ip->i_d.di_onlink = 0;
302 			memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
303 		}
304 	}
305 
306 	switch (ip->i_d.di_format) {
307 	case XFS_DINODE_FMT_EXTENTS:
308 		ASSERT(!(iip->ili_format.ilf_fields &
309 			 (XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
310 			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
311 		if (iip->ili_format.ilf_fields & XFS_ILOG_DEXT) {
312 			ASSERT(ip->i_df.if_bytes > 0);
313 			ASSERT(ip->i_df.if_u1.if_extents != NULL);
314 			ASSERT(ip->i_d.di_nextents > 0);
315 			ASSERT(iip->ili_extents_buf == NULL);
316 			ASSERT((ip->i_df.if_bytes /
317 				(uint)sizeof(xfs_bmbt_rec_t)) > 0);
318 #ifdef XFS_NATIVE_HOST
319                        if (ip->i_d.di_nextents == ip->i_df.if_bytes /
320                                                (uint)sizeof(xfs_bmbt_rec_t)) {
321 				/*
322 				 * There are no delayed allocation
323 				 * extents, so just point to the
324 				 * real extents array.
325 				 */
326 				vecp->i_addr = ip->i_df.if_u1.if_extents;
327 				vecp->i_len = ip->i_df.if_bytes;
328 				vecp->i_type = XLOG_REG_TYPE_IEXT;
329 			} else
330 #endif
331 			{
332 				/*
333 				 * There are delayed allocation extents
334 				 * in the inode, or we need to convert
335 				 * the extents to on disk format.
336 				 * Use xfs_iextents_copy()
337 				 * to copy only the real extents into
338 				 * a separate buffer.  We'll free the
339 				 * buffer in the unlock routine.
340 				 */
341 				ext_buffer = kmem_alloc(ip->i_df.if_bytes,
342 					KM_SLEEP);
343 				iip->ili_extents_buf = ext_buffer;
344 				vecp->i_addr = ext_buffer;
345 				vecp->i_len = xfs_iextents_copy(ip, ext_buffer,
346 						XFS_DATA_FORK);
347 				vecp->i_type = XLOG_REG_TYPE_IEXT;
348 			}
349 			ASSERT(vecp->i_len <= ip->i_df.if_bytes);
350 			iip->ili_format.ilf_dsize = vecp->i_len;
351 			vecp++;
352 			nvecs++;
353 		}
354 		break;
355 
356 	case XFS_DINODE_FMT_BTREE:
357 		ASSERT(!(iip->ili_format.ilf_fields &
358 			 (XFS_ILOG_DDATA | XFS_ILOG_DEXT |
359 			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
360 		if (iip->ili_format.ilf_fields & XFS_ILOG_DBROOT) {
361 			ASSERT(ip->i_df.if_broot_bytes > 0);
362 			ASSERT(ip->i_df.if_broot != NULL);
363 			vecp->i_addr = ip->i_df.if_broot;
364 			vecp->i_len = ip->i_df.if_broot_bytes;
365 			vecp->i_type = XLOG_REG_TYPE_IBROOT;
366 			vecp++;
367 			nvecs++;
368 			iip->ili_format.ilf_dsize = ip->i_df.if_broot_bytes;
369 		}
370 		break;
371 
372 	case XFS_DINODE_FMT_LOCAL:
373 		ASSERT(!(iip->ili_format.ilf_fields &
374 			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
375 			  XFS_ILOG_DEV | XFS_ILOG_UUID)));
376 		if (iip->ili_format.ilf_fields & XFS_ILOG_DDATA) {
377 			ASSERT(ip->i_df.if_bytes > 0);
378 			ASSERT(ip->i_df.if_u1.if_data != NULL);
379 			ASSERT(ip->i_d.di_size > 0);
380 
381 			vecp->i_addr = ip->i_df.if_u1.if_data;
382 			/*
383 			 * Round i_bytes up to a word boundary.
384 			 * The underlying memory is guaranteed to
385 			 * to be there by xfs_idata_realloc().
386 			 */
387 			data_bytes = roundup(ip->i_df.if_bytes, 4);
388 			ASSERT((ip->i_df.if_real_bytes == 0) ||
389 			       (ip->i_df.if_real_bytes == data_bytes));
390 			vecp->i_len = (int)data_bytes;
391 			vecp->i_type = XLOG_REG_TYPE_ILOCAL;
392 			vecp++;
393 			nvecs++;
394 			iip->ili_format.ilf_dsize = (unsigned)data_bytes;
395 		}
396 		break;
397 
398 	case XFS_DINODE_FMT_DEV:
399 		ASSERT(!(iip->ili_format.ilf_fields &
400 			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
401 			  XFS_ILOG_DDATA | XFS_ILOG_UUID)));
402 		if (iip->ili_format.ilf_fields & XFS_ILOG_DEV) {
403 			iip->ili_format.ilf_u.ilfu_rdev =
404 				ip->i_df.if_u2.if_rdev;
405 		}
406 		break;
407 
408 	case XFS_DINODE_FMT_UUID:
409 		ASSERT(!(iip->ili_format.ilf_fields &
410 			 (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
411 			  XFS_ILOG_DDATA | XFS_ILOG_DEV)));
412 		if (iip->ili_format.ilf_fields & XFS_ILOG_UUID) {
413 			iip->ili_format.ilf_u.ilfu_uuid =
414 				ip->i_df.if_u2.if_uuid;
415 		}
416 		break;
417 
418 	default:
419 		ASSERT(0);
420 		break;
421 	}
422 
423 	/*
424 	 * If there are no attributes associated with the file,
425 	 * then we're done.
426 	 * Assert that no attribute-related log flags are set.
427 	 */
428 	if (!XFS_IFORK_Q(ip)) {
429 		ASSERT(nvecs == lip->li_desc->lid_size);
430 		iip->ili_format.ilf_size = nvecs;
431 		ASSERT(!(iip->ili_format.ilf_fields &
432 			 (XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT)));
433 		return;
434 	}
435 
436 	switch (ip->i_d.di_aformat) {
437 	case XFS_DINODE_FMT_EXTENTS:
438 		ASSERT(!(iip->ili_format.ilf_fields &
439 			 (XFS_ILOG_ADATA | XFS_ILOG_ABROOT)));
440 		if (iip->ili_format.ilf_fields & XFS_ILOG_AEXT) {
441 #ifdef DEBUG
442 			int nrecs = ip->i_afp->if_bytes /
443 				(uint)sizeof(xfs_bmbt_rec_t);
444 			ASSERT(nrecs > 0);
445 			ASSERT(nrecs == ip->i_d.di_anextents);
446 			ASSERT(ip->i_afp->if_bytes > 0);
447 			ASSERT(ip->i_afp->if_u1.if_extents != NULL);
448 			ASSERT(ip->i_d.di_anextents > 0);
449 #endif
450 #ifdef XFS_NATIVE_HOST
451 			/*
452 			 * There are not delayed allocation extents
453 			 * for attributes, so just point at the array.
454 			 */
455 			vecp->i_addr = ip->i_afp->if_u1.if_extents;
456 			vecp->i_len = ip->i_afp->if_bytes;
457 #else
458 			ASSERT(iip->ili_aextents_buf == NULL);
459 			/*
460 			 * Need to endian flip before logging
461 			 */
462 			ext_buffer = kmem_alloc(ip->i_afp->if_bytes,
463 				KM_SLEEP);
464 			iip->ili_aextents_buf = ext_buffer;
465 			vecp->i_addr = ext_buffer;
466 			vecp->i_len = xfs_iextents_copy(ip, ext_buffer,
467 					XFS_ATTR_FORK);
468 #endif
469 			vecp->i_type = XLOG_REG_TYPE_IATTR_EXT;
470 			iip->ili_format.ilf_asize = vecp->i_len;
471 			vecp++;
472 			nvecs++;
473 		}
474 		break;
475 
476 	case XFS_DINODE_FMT_BTREE:
477 		ASSERT(!(iip->ili_format.ilf_fields &
478 			 (XFS_ILOG_ADATA | XFS_ILOG_AEXT)));
479 		if (iip->ili_format.ilf_fields & XFS_ILOG_ABROOT) {
480 			ASSERT(ip->i_afp->if_broot_bytes > 0);
481 			ASSERT(ip->i_afp->if_broot != NULL);
482 			vecp->i_addr = ip->i_afp->if_broot;
483 			vecp->i_len = ip->i_afp->if_broot_bytes;
484 			vecp->i_type = XLOG_REG_TYPE_IATTR_BROOT;
485 			vecp++;
486 			nvecs++;
487 			iip->ili_format.ilf_asize = ip->i_afp->if_broot_bytes;
488 		}
489 		break;
490 
491 	case XFS_DINODE_FMT_LOCAL:
492 		ASSERT(!(iip->ili_format.ilf_fields &
493 			 (XFS_ILOG_ABROOT | XFS_ILOG_AEXT)));
494 		if (iip->ili_format.ilf_fields & XFS_ILOG_ADATA) {
495 			ASSERT(ip->i_afp->if_bytes > 0);
496 			ASSERT(ip->i_afp->if_u1.if_data != NULL);
497 
498 			vecp->i_addr = ip->i_afp->if_u1.if_data;
499 			/*
500 			 * Round i_bytes up to a word boundary.
501 			 * The underlying memory is guaranteed to
502 			 * to be there by xfs_idata_realloc().
503 			 */
504 			data_bytes = roundup(ip->i_afp->if_bytes, 4);
505 			ASSERT((ip->i_afp->if_real_bytes == 0) ||
506 			       (ip->i_afp->if_real_bytes == data_bytes));
507 			vecp->i_len = (int)data_bytes;
508 			vecp->i_type = XLOG_REG_TYPE_IATTR_LOCAL;
509 			vecp++;
510 			nvecs++;
511 			iip->ili_format.ilf_asize = (unsigned)data_bytes;
512 		}
513 		break;
514 
515 	default:
516 		ASSERT(0);
517 		break;
518 	}
519 
520 	ASSERT(nvecs == lip->li_desc->lid_size);
521 	iip->ili_format.ilf_size = nvecs;
522 }
523 
524 
525 /*
526  * This is called to pin the inode associated with the inode log
527  * item in memory so it cannot be written out.
528  */
529 STATIC void
530 xfs_inode_item_pin(
531 	struct xfs_log_item	*lip)
532 {
533 	struct xfs_inode	*ip = INODE_ITEM(lip)->ili_inode;
534 
535 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
536 
537 	trace_xfs_inode_pin(ip, _RET_IP_);
538 	atomic_inc(&ip->i_pincount);
539 }
540 
541 
542 /*
543  * This is called to unpin the inode associated with the inode log
544  * item which was previously pinned with a call to xfs_inode_item_pin().
545  *
546  * Also wake up anyone in xfs_iunpin_wait() if the count goes to 0.
547  */
548 STATIC void
549 xfs_inode_item_unpin(
550 	struct xfs_log_item	*lip,
551 	int			remove)
552 {
553 	struct xfs_inode	*ip = INODE_ITEM(lip)->ili_inode;
554 
555 	trace_xfs_inode_unpin(ip, _RET_IP_);
556 	ASSERT(atomic_read(&ip->i_pincount) > 0);
557 	if (atomic_dec_and_test(&ip->i_pincount))
558 		wake_up(&ip->i_ipin_wait);
559 }
560 
561 /*
562  * This is called to attempt to lock the inode associated with this
563  * inode log item, in preparation for the push routine which does the actual
564  * iflush.  Don't sleep on the inode lock or the flush lock.
565  *
566  * If the flush lock is already held, indicating that the inode has
567  * been or is in the process of being flushed, then (ideally) we'd like to
568  * see if the inode's buffer is still incore, and if so give it a nudge.
569  * We delay doing so until the pushbuf routine, though, to avoid holding
570  * the AIL lock across a call to the blackhole which is the buffer cache.
571  * Also we don't want to sleep in any device strategy routines, which can happen
572  * if we do the subsequent bawrite in here.
573  */
574 STATIC uint
575 xfs_inode_item_trylock(
576 	struct xfs_log_item	*lip)
577 {
578 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
579 	struct xfs_inode	*ip = iip->ili_inode;
580 
581 	if (xfs_ipincount(ip) > 0)
582 		return XFS_ITEM_PINNED;
583 
584 	if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED))
585 		return XFS_ITEM_LOCKED;
586 
587 	if (!xfs_iflock_nowait(ip)) {
588 		/*
589 		 * inode has already been flushed to the backing buffer,
590 		 * leave it locked in shared mode, pushbuf routine will
591 		 * unlock it.
592 		 */
593 		return XFS_ITEM_PUSHBUF;
594 	}
595 
596 	/* Stale items should force out the iclog */
597 	if (ip->i_flags & XFS_ISTALE) {
598 		xfs_ifunlock(ip);
599 		/*
600 		 * we hold the AIL lock - notify the unlock routine of this
601 		 * so it doesn't try to get the lock again.
602 		 */
603 		xfs_iunlock(ip, XFS_ILOCK_SHARED|XFS_IUNLOCK_NONOTIFY);
604 		return XFS_ITEM_PINNED;
605 	}
606 
607 #ifdef DEBUG
608 	if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
609 		ASSERT(iip->ili_format.ilf_fields != 0);
610 		ASSERT(iip->ili_logged == 0);
611 		ASSERT(lip->li_flags & XFS_LI_IN_AIL);
612 	}
613 #endif
614 	return XFS_ITEM_SUCCESS;
615 }
616 
617 /*
618  * Unlock the inode associated with the inode log item.
619  * Clear the fields of the inode and inode log item that
620  * are specific to the current transaction.  If the
621  * hold flags is set, do not unlock the inode.
622  */
623 STATIC void
624 xfs_inode_item_unlock(
625 	struct xfs_log_item	*lip)
626 {
627 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
628 	struct xfs_inode	*ip = iip->ili_inode;
629 	unsigned short		lock_flags;
630 
631 	ASSERT(iip->ili_inode->i_itemp != NULL);
632 	ASSERT(xfs_isilocked(iip->ili_inode, XFS_ILOCK_EXCL));
633 
634 	/*
635 	 * Clear the transaction pointer in the inode.
636 	 */
637 	ip->i_transp = NULL;
638 
639 	/*
640 	 * If the inode needed a separate buffer with which to log
641 	 * its extents, then free it now.
642 	 */
643 	if (iip->ili_extents_buf != NULL) {
644 		ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS);
645 		ASSERT(ip->i_d.di_nextents > 0);
646 		ASSERT(iip->ili_format.ilf_fields & XFS_ILOG_DEXT);
647 		ASSERT(ip->i_df.if_bytes > 0);
648 		kmem_free(iip->ili_extents_buf);
649 		iip->ili_extents_buf = NULL;
650 	}
651 	if (iip->ili_aextents_buf != NULL) {
652 		ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS);
653 		ASSERT(ip->i_d.di_anextents > 0);
654 		ASSERT(iip->ili_format.ilf_fields & XFS_ILOG_AEXT);
655 		ASSERT(ip->i_afp->if_bytes > 0);
656 		kmem_free(iip->ili_aextents_buf);
657 		iip->ili_aextents_buf = NULL;
658 	}
659 
660 	lock_flags = iip->ili_lock_flags;
661 	iip->ili_lock_flags = 0;
662 	if (lock_flags) {
663 		xfs_iunlock(iip->ili_inode, lock_flags);
664 		IRELE(iip->ili_inode);
665 	}
666 }
667 
668 /*
669  * This is called to find out where the oldest active copy of the
670  * inode log item in the on disk log resides now that the last log
671  * write of it completed at the given lsn.  Since we always re-log
672  * all dirty data in an inode, the latest copy in the on disk log
673  * is the only one that matters.  Therefore, simply return the
674  * given lsn.
675  */
676 STATIC xfs_lsn_t
677 xfs_inode_item_committed(
678 	struct xfs_log_item	*lip,
679 	xfs_lsn_t		lsn)
680 {
681 	return lsn;
682 }
683 
684 /*
685  * This gets called by xfs_trans_push_ail(), when IOP_TRYLOCK
686  * failed to get the inode flush lock but did get the inode locked SHARED.
687  * Here we're trying to see if the inode buffer is incore, and if so whether it's
688  * marked delayed write. If that's the case, we'll promote it and that will
689  * allow the caller to write the buffer by triggering the xfsbufd to run.
690  */
691 STATIC void
692 xfs_inode_item_pushbuf(
693 	struct xfs_log_item	*lip)
694 {
695 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
696 	struct xfs_inode	*ip = iip->ili_inode;
697 	struct xfs_buf		*bp;
698 
699 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));
700 
701 	/*
702 	 * If a flush is not in progress anymore, chances are that the
703 	 * inode was taken off the AIL. So, just get out.
704 	 */
705 	if (completion_done(&ip->i_flush) ||
706 	    !(lip->li_flags & XFS_LI_IN_AIL)) {
707 		xfs_iunlock(ip, XFS_ILOCK_SHARED);
708 		return;
709 	}
710 
711 	bp = xfs_incore(ip->i_mount->m_ddev_targp, iip->ili_format.ilf_blkno,
712 			iip->ili_format.ilf_len, XBF_TRYLOCK);
713 
714 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
715 	if (!bp)
716 		return;
717 	if (XFS_BUF_ISDELAYWRITE(bp))
718 		xfs_buf_delwri_promote(bp);
719 	xfs_buf_relse(bp);
720 }
721 
722 /*
723  * This is called to asynchronously write the inode associated with this
724  * inode log item out to disk. The inode will already have been locked by
725  * a successful call to xfs_inode_item_trylock().
726  */
727 STATIC void
728 xfs_inode_item_push(
729 	struct xfs_log_item	*lip)
730 {
731 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
732 	struct xfs_inode	*ip = iip->ili_inode;
733 
734 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));
735 	ASSERT(!completion_done(&ip->i_flush));
736 
737 	/*
738 	 * Since we were able to lock the inode's flush lock and
739 	 * we found it on the AIL, the inode must be dirty.  This
740 	 * is because the inode is removed from the AIL while still
741 	 * holding the flush lock in xfs_iflush_done().  Thus, if
742 	 * we found it in the AIL and were able to obtain the flush
743 	 * lock without sleeping, then there must not have been
744 	 * anyone in the process of flushing the inode.
745 	 */
746 	ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) ||
747 	       iip->ili_format.ilf_fields != 0);
748 
749 	/*
750 	 * Push the inode to it's backing buffer. This will not remove the
751 	 * inode from the AIL - a further push will be required to trigger a
752 	 * buffer push. However, this allows all the dirty inodes to be pushed
753 	 * to the buffer before it is pushed to disk. THe buffer IO completion
754 	 * will pull th einode from the AIL, mark it clean and unlock the flush
755 	 * lock.
756 	 */
757 	(void) xfs_iflush(ip, 0);
758 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
759 }
760 
761 /*
762  * XXX rcc - this one really has to do something.  Probably needs
763  * to stamp in a new field in the incore inode.
764  */
765 STATIC void
766 xfs_inode_item_committing(
767 	struct xfs_log_item	*lip,
768 	xfs_lsn_t		lsn)
769 {
770 	INODE_ITEM(lip)->ili_last_lsn = lsn;
771 }
772 
773 /*
774  * This is the ops vector shared by all buf log items.
775  */
776 static struct xfs_item_ops xfs_inode_item_ops = {
777 	.iop_size	= xfs_inode_item_size,
778 	.iop_format	= xfs_inode_item_format,
779 	.iop_pin	= xfs_inode_item_pin,
780 	.iop_unpin	= xfs_inode_item_unpin,
781 	.iop_trylock	= xfs_inode_item_trylock,
782 	.iop_unlock	= xfs_inode_item_unlock,
783 	.iop_committed	= xfs_inode_item_committed,
784 	.iop_push	= xfs_inode_item_push,
785 	.iop_pushbuf	= xfs_inode_item_pushbuf,
786 	.iop_committing = xfs_inode_item_committing
787 };
788 
789 
790 /*
791  * Initialize the inode log item for a newly allocated (in-core) inode.
792  */
793 void
794 xfs_inode_item_init(
795 	struct xfs_inode	*ip,
796 	struct xfs_mount	*mp)
797 {
798 	struct xfs_inode_log_item *iip;
799 
800 	ASSERT(ip->i_itemp == NULL);
801 	iip = ip->i_itemp = kmem_zone_zalloc(xfs_ili_zone, KM_SLEEP);
802 
803 	iip->ili_inode = ip;
804 	xfs_log_item_init(mp, &iip->ili_item, XFS_LI_INODE,
805 						&xfs_inode_item_ops);
806 	iip->ili_format.ilf_type = XFS_LI_INODE;
807 	iip->ili_format.ilf_ino = ip->i_ino;
808 	iip->ili_format.ilf_blkno = ip->i_imap.im_blkno;
809 	iip->ili_format.ilf_len = ip->i_imap.im_len;
810 	iip->ili_format.ilf_boffset = ip->i_imap.im_boffset;
811 }
812 
813 /*
814  * Free the inode log item and any memory hanging off of it.
815  */
816 void
817 xfs_inode_item_destroy(
818 	xfs_inode_t	*ip)
819 {
820 #ifdef XFS_TRANS_DEBUG
821 	if (ip->i_itemp->ili_root_size != 0) {
822 		kmem_free(ip->i_itemp->ili_orig_root);
823 	}
824 #endif
825 	kmem_zone_free(xfs_ili_zone, ip->i_itemp);
826 }
827 
828 
829 /*
830  * This is the inode flushing I/O completion routine.  It is called
831  * from interrupt level when the buffer containing the inode is
832  * flushed to disk.  It is responsible for removing the inode item
833  * from the AIL if it has not been re-logged, and unlocking the inode's
834  * flush lock.
835  */
836 void
837 xfs_iflush_done(
838 	struct xfs_buf		*bp,
839 	struct xfs_log_item	*lip)
840 {
841 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
842 	xfs_inode_t		*ip = iip->ili_inode;
843 	struct xfs_ail		*ailp = lip->li_ailp;
844 
845 	/*
846 	 * We only want to pull the item from the AIL if it is
847 	 * actually there and its location in the log has not
848 	 * changed since we started the flush.  Thus, we only bother
849 	 * if the ili_logged flag is set and the inode's lsn has not
850 	 * changed.  First we check the lsn outside
851 	 * the lock since it's cheaper, and then we recheck while
852 	 * holding the lock before removing the inode from the AIL.
853 	 */
854 	if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) {
855 		spin_lock(&ailp->xa_lock);
856 		if (lip->li_lsn == iip->ili_flush_lsn) {
857 			/* xfs_trans_ail_delete() drops the AIL lock. */
858 			xfs_trans_ail_delete(ailp, lip);
859 		} else {
860 			spin_unlock(&ailp->xa_lock);
861 		}
862 	}
863 
864 	iip->ili_logged = 0;
865 
866 	/*
867 	 * Clear the ili_last_fields bits now that we know that the
868 	 * data corresponding to them is safely on disk.
869 	 */
870 	iip->ili_last_fields = 0;
871 
872 	/*
873 	 * Release the inode's flush lock since we're done with it.
874 	 */
875 	xfs_ifunlock(ip);
876 }
877 
878 /*
879  * This is the inode flushing abort routine.  It is called
880  * from xfs_iflush when the filesystem is shutting down to clean
881  * up the inode state.
882  * It is responsible for removing the inode item
883  * from the AIL if it has not been re-logged, and unlocking the inode's
884  * flush lock.
885  */
886 void
887 xfs_iflush_abort(
888 	xfs_inode_t		*ip)
889 {
890 	xfs_inode_log_item_t	*iip = ip->i_itemp;
891 
892 	iip = ip->i_itemp;
893 	if (iip) {
894 		struct xfs_ail	*ailp = iip->ili_item.li_ailp;
895 		if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {
896 			spin_lock(&ailp->xa_lock);
897 			if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {
898 				/* xfs_trans_ail_delete() drops the AIL lock. */
899 				xfs_trans_ail_delete(ailp, (xfs_log_item_t *)iip);
900 			} else
901 				spin_unlock(&ailp->xa_lock);
902 		}
903 		iip->ili_logged = 0;
904 		/*
905 		 * Clear the ili_last_fields bits now that we know that the
906 		 * data corresponding to them is safely on disk.
907 		 */
908 		iip->ili_last_fields = 0;
909 		/*
910 		 * Clear the inode logging fields so no more flushes are
911 		 * attempted.
912 		 */
913 		iip->ili_format.ilf_fields = 0;
914 	}
915 	/*
916 	 * Release the inode's flush lock since we're done with it.
917 	 */
918 	xfs_ifunlock(ip);
919 }
920 
921 void
922 xfs_istale_done(
923 	struct xfs_buf		*bp,
924 	struct xfs_log_item	*lip)
925 {
926 	xfs_iflush_abort(INODE_ITEM(lip)->ili_inode);
927 }
928 
929 /*
930  * convert an xfs_inode_log_format struct from either 32 or 64 bit versions
931  * (which can have different field alignments) to the native version
932  */
933 int
934 xfs_inode_item_format_convert(
935 	xfs_log_iovec_t		*buf,
936 	xfs_inode_log_format_t	*in_f)
937 {
938 	if (buf->i_len == sizeof(xfs_inode_log_format_32_t)) {
939 		xfs_inode_log_format_32_t *in_f32 = buf->i_addr;
940 
941 		in_f->ilf_type = in_f32->ilf_type;
942 		in_f->ilf_size = in_f32->ilf_size;
943 		in_f->ilf_fields = in_f32->ilf_fields;
944 		in_f->ilf_asize = in_f32->ilf_asize;
945 		in_f->ilf_dsize = in_f32->ilf_dsize;
946 		in_f->ilf_ino = in_f32->ilf_ino;
947 		/* copy biggest field of ilf_u */
948 		memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
949 		       in_f32->ilf_u.ilfu_uuid.__u_bits,
950 		       sizeof(uuid_t));
951 		in_f->ilf_blkno = in_f32->ilf_blkno;
952 		in_f->ilf_len = in_f32->ilf_len;
953 		in_f->ilf_boffset = in_f32->ilf_boffset;
954 		return 0;
955 	} else if (buf->i_len == sizeof(xfs_inode_log_format_64_t)){
956 		xfs_inode_log_format_64_t *in_f64 = buf->i_addr;
957 
958 		in_f->ilf_type = in_f64->ilf_type;
959 		in_f->ilf_size = in_f64->ilf_size;
960 		in_f->ilf_fields = in_f64->ilf_fields;
961 		in_f->ilf_asize = in_f64->ilf_asize;
962 		in_f->ilf_dsize = in_f64->ilf_dsize;
963 		in_f->ilf_ino = in_f64->ilf_ino;
964 		/* copy biggest field of ilf_u */
965 		memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
966 		       in_f64->ilf_u.ilfu_uuid.__u_bits,
967 		       sizeof(uuid_t));
968 		in_f->ilf_blkno = in_f64->ilf_blkno;
969 		in_f->ilf_len = in_f64->ilf_len;
970 		in_f->ilf_boffset = in_f64->ilf_boffset;
971 		return 0;
972 	}
973 	return EFSCORRUPTED;
974 }
975