xref: /openbmc/linux/fs/xfs/xfs_trans_buf.c (revision 275876e2)
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_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_mount.h"
27 #include "xfs_inode.h"
28 #include "xfs_trans.h"
29 #include "xfs_buf_item.h"
30 #include "xfs_trans_priv.h"
31 #include "xfs_error.h"
32 #include "xfs_trace.h"
33 
34 /*
35  * Check to see if a buffer matching the given parameters is already
36  * a part of the given transaction.
37  */
38 STATIC struct xfs_buf *
39 xfs_trans_buf_item_match(
40 	struct xfs_trans	*tp,
41 	struct xfs_buftarg	*target,
42 	struct xfs_buf_map	*map,
43 	int			nmaps)
44 {
45 	struct xfs_log_item_desc *lidp;
46 	struct xfs_buf_log_item	*blip;
47 	int			len = 0;
48 	int			i;
49 
50 	for (i = 0; i < nmaps; i++)
51 		len += map[i].bm_len;
52 
53 	list_for_each_entry(lidp, &tp->t_items, lid_trans) {
54 		blip = (struct xfs_buf_log_item *)lidp->lid_item;
55 		if (blip->bli_item.li_type == XFS_LI_BUF &&
56 		    blip->bli_buf->b_target == target &&
57 		    XFS_BUF_ADDR(blip->bli_buf) == map[0].bm_bn &&
58 		    blip->bli_buf->b_length == len) {
59 			ASSERT(blip->bli_buf->b_map_count == nmaps);
60 			return blip->bli_buf;
61 		}
62 	}
63 
64 	return NULL;
65 }
66 
67 /*
68  * Add the locked buffer to the transaction.
69  *
70  * The buffer must be locked, and it cannot be associated with any
71  * transaction.
72  *
73  * If the buffer does not yet have a buf log item associated with it,
74  * then allocate one for it.  Then add the buf item to the transaction.
75  */
76 STATIC void
77 _xfs_trans_bjoin(
78 	struct xfs_trans	*tp,
79 	struct xfs_buf		*bp,
80 	int			reset_recur)
81 {
82 	struct xfs_buf_log_item	*bip;
83 
84 	ASSERT(bp->b_transp == NULL);
85 
86 	/*
87 	 * The xfs_buf_log_item pointer is stored in b_fsprivate.  If
88 	 * it doesn't have one yet, then allocate one and initialize it.
89 	 * The checks to see if one is there are in xfs_buf_item_init().
90 	 */
91 	xfs_buf_item_init(bp, tp->t_mountp);
92 	bip = bp->b_fspriv;
93 	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
94 	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
95 	ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED));
96 	if (reset_recur)
97 		bip->bli_recur = 0;
98 
99 	/*
100 	 * Take a reference for this transaction on the buf item.
101 	 */
102 	atomic_inc(&bip->bli_refcount);
103 
104 	/*
105 	 * Get a log_item_desc to point at the new item.
106 	 */
107 	xfs_trans_add_item(tp, &bip->bli_item);
108 
109 	/*
110 	 * Initialize b_fsprivate2 so we can find it with incore_match()
111 	 * in xfs_trans_get_buf() and friends above.
112 	 */
113 	bp->b_transp = tp;
114 
115 }
116 
117 void
118 xfs_trans_bjoin(
119 	struct xfs_trans	*tp,
120 	struct xfs_buf		*bp)
121 {
122 	_xfs_trans_bjoin(tp, bp, 0);
123 	trace_xfs_trans_bjoin(bp->b_fspriv);
124 }
125 
126 /*
127  * Get and lock the buffer for the caller if it is not already
128  * locked within the given transaction.  If it is already locked
129  * within the transaction, just increment its lock recursion count
130  * and return a pointer to it.
131  *
132  * If the transaction pointer is NULL, make this just a normal
133  * get_buf() call.
134  */
135 struct xfs_buf *
136 xfs_trans_get_buf_map(
137 	struct xfs_trans	*tp,
138 	struct xfs_buftarg	*target,
139 	struct xfs_buf_map	*map,
140 	int			nmaps,
141 	xfs_buf_flags_t		flags)
142 {
143 	xfs_buf_t		*bp;
144 	xfs_buf_log_item_t	*bip;
145 
146 	if (!tp)
147 		return xfs_buf_get_map(target, map, nmaps, flags);
148 
149 	/*
150 	 * If we find the buffer in the cache with this transaction
151 	 * pointer in its b_fsprivate2 field, then we know we already
152 	 * have it locked.  In this case we just increment the lock
153 	 * recursion count and return the buffer to the caller.
154 	 */
155 	bp = xfs_trans_buf_item_match(tp, target, map, nmaps);
156 	if (bp != NULL) {
157 		ASSERT(xfs_buf_islocked(bp));
158 		if (XFS_FORCED_SHUTDOWN(tp->t_mountp)) {
159 			xfs_buf_stale(bp);
160 			XFS_BUF_DONE(bp);
161 		}
162 
163 		ASSERT(bp->b_transp == tp);
164 		bip = bp->b_fspriv;
165 		ASSERT(bip != NULL);
166 		ASSERT(atomic_read(&bip->bli_refcount) > 0);
167 		bip->bli_recur++;
168 		trace_xfs_trans_get_buf_recur(bip);
169 		return bp;
170 	}
171 
172 	bp = xfs_buf_get_map(target, map, nmaps, flags);
173 	if (bp == NULL) {
174 		return NULL;
175 	}
176 
177 	ASSERT(!bp->b_error);
178 
179 	_xfs_trans_bjoin(tp, bp, 1);
180 	trace_xfs_trans_get_buf(bp->b_fspriv);
181 	return bp;
182 }
183 
184 /*
185  * Get and lock the superblock buffer of this file system for the
186  * given transaction.
187  *
188  * We don't need to use incore_match() here, because the superblock
189  * buffer is a private buffer which we keep a pointer to in the
190  * mount structure.
191  */
192 xfs_buf_t *
193 xfs_trans_getsb(xfs_trans_t	*tp,
194 		struct xfs_mount *mp,
195 		int		flags)
196 {
197 	xfs_buf_t		*bp;
198 	xfs_buf_log_item_t	*bip;
199 
200 	/*
201 	 * Default to just trying to lock the superblock buffer
202 	 * if tp is NULL.
203 	 */
204 	if (tp == NULL)
205 		return xfs_getsb(mp, flags);
206 
207 	/*
208 	 * If the superblock buffer already has this transaction
209 	 * pointer in its b_fsprivate2 field, then we know we already
210 	 * have it locked.  In this case we just increment the lock
211 	 * recursion count and return the buffer to the caller.
212 	 */
213 	bp = mp->m_sb_bp;
214 	if (bp->b_transp == tp) {
215 		bip = bp->b_fspriv;
216 		ASSERT(bip != NULL);
217 		ASSERT(atomic_read(&bip->bli_refcount) > 0);
218 		bip->bli_recur++;
219 		trace_xfs_trans_getsb_recur(bip);
220 		return bp;
221 	}
222 
223 	bp = xfs_getsb(mp, flags);
224 	if (bp == NULL)
225 		return NULL;
226 
227 	_xfs_trans_bjoin(tp, bp, 1);
228 	trace_xfs_trans_getsb(bp->b_fspriv);
229 	return bp;
230 }
231 
232 #ifdef DEBUG
233 xfs_buftarg_t *xfs_error_target;
234 int	xfs_do_error;
235 int	xfs_req_num;
236 int	xfs_error_mod = 33;
237 #endif
238 
239 /*
240  * Get and lock the buffer for the caller if it is not already
241  * locked within the given transaction.  If it has not yet been
242  * read in, read it from disk. If it is already locked
243  * within the transaction and already read in, just increment its
244  * lock recursion count and return a pointer to it.
245  *
246  * If the transaction pointer is NULL, make this just a normal
247  * read_buf() call.
248  */
249 int
250 xfs_trans_read_buf_map(
251 	struct xfs_mount	*mp,
252 	struct xfs_trans	*tp,
253 	struct xfs_buftarg	*target,
254 	struct xfs_buf_map	*map,
255 	int			nmaps,
256 	xfs_buf_flags_t		flags,
257 	struct xfs_buf		**bpp,
258 	const struct xfs_buf_ops *ops)
259 {
260 	xfs_buf_t		*bp;
261 	xfs_buf_log_item_t	*bip;
262 	int			error;
263 
264 	*bpp = NULL;
265 	if (!tp) {
266 		bp = xfs_buf_read_map(target, map, nmaps, flags, ops);
267 		if (!bp)
268 			return (flags & XBF_TRYLOCK) ?
269 					-EAGAIN : -ENOMEM;
270 
271 		if (bp->b_error) {
272 			error = bp->b_error;
273 			xfs_buf_ioerror_alert(bp, __func__);
274 			XFS_BUF_UNDONE(bp);
275 			xfs_buf_stale(bp);
276 			xfs_buf_relse(bp);
277 
278 			/* bad CRC means corrupted metadata */
279 			if (error == -EFSBADCRC)
280 				error = -EFSCORRUPTED;
281 			return error;
282 		}
283 #ifdef DEBUG
284 		if (xfs_do_error) {
285 			if (xfs_error_target == target) {
286 				if (((xfs_req_num++) % xfs_error_mod) == 0) {
287 					xfs_buf_relse(bp);
288 					xfs_debug(mp, "Returning error!");
289 					return -EIO;
290 				}
291 			}
292 		}
293 #endif
294 		if (XFS_FORCED_SHUTDOWN(mp))
295 			goto shutdown_abort;
296 		*bpp = bp;
297 		return 0;
298 	}
299 
300 	/*
301 	 * If we find the buffer in the cache with this transaction
302 	 * pointer in its b_fsprivate2 field, then we know we already
303 	 * have it locked.  If it is already read in we just increment
304 	 * the lock recursion count and return the buffer to the caller.
305 	 * If the buffer is not yet read in, then we read it in, increment
306 	 * the lock recursion count, and return it to the caller.
307 	 */
308 	bp = xfs_trans_buf_item_match(tp, target, map, nmaps);
309 	if (bp != NULL) {
310 		ASSERT(xfs_buf_islocked(bp));
311 		ASSERT(bp->b_transp == tp);
312 		ASSERT(bp->b_fspriv != NULL);
313 		ASSERT(!bp->b_error);
314 		if (!(XFS_BUF_ISDONE(bp))) {
315 			trace_xfs_trans_read_buf_io(bp, _RET_IP_);
316 			ASSERT(!XFS_BUF_ISASYNC(bp));
317 			ASSERT(bp->b_iodone == NULL);
318 			XFS_BUF_READ(bp);
319 			bp->b_ops = ops;
320 
321 			/*
322 			 * XXX(hch): clean up the error handling here to be less
323 			 * of a mess..
324 			 */
325 			if (XFS_FORCED_SHUTDOWN(mp)) {
326 				trace_xfs_bdstrat_shut(bp, _RET_IP_);
327 				xfs_bioerror_relse(bp);
328 			} else {
329 				xfs_buf_iorequest(bp);
330 			}
331 
332 			error = xfs_buf_iowait(bp);
333 			if (error) {
334 				xfs_buf_ioerror_alert(bp, __func__);
335 				xfs_buf_relse(bp);
336 				/*
337 				 * We can gracefully recover from most read
338 				 * errors. Ones we can't are those that happen
339 				 * after the transaction's already dirty.
340 				 */
341 				if (tp->t_flags & XFS_TRANS_DIRTY)
342 					xfs_force_shutdown(tp->t_mountp,
343 							SHUTDOWN_META_IO_ERROR);
344 				/* bad CRC means corrupted metadata */
345 				if (error == -EFSBADCRC)
346 					error = -EFSCORRUPTED;
347 				return error;
348 			}
349 		}
350 		/*
351 		 * We never locked this buf ourselves, so we shouldn't
352 		 * brelse it either. Just get out.
353 		 */
354 		if (XFS_FORCED_SHUTDOWN(mp)) {
355 			trace_xfs_trans_read_buf_shut(bp, _RET_IP_);
356 			*bpp = NULL;
357 			return -EIO;
358 		}
359 
360 
361 		bip = bp->b_fspriv;
362 		bip->bli_recur++;
363 
364 		ASSERT(atomic_read(&bip->bli_refcount) > 0);
365 		trace_xfs_trans_read_buf_recur(bip);
366 		*bpp = bp;
367 		return 0;
368 	}
369 
370 	bp = xfs_buf_read_map(target, map, nmaps, flags, ops);
371 	if (bp == NULL) {
372 		*bpp = NULL;
373 		return (flags & XBF_TRYLOCK) ?
374 					0 : -ENOMEM;
375 	}
376 	if (bp->b_error) {
377 		error = bp->b_error;
378 		xfs_buf_stale(bp);
379 		XFS_BUF_DONE(bp);
380 		xfs_buf_ioerror_alert(bp, __func__);
381 		if (tp->t_flags & XFS_TRANS_DIRTY)
382 			xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR);
383 		xfs_buf_relse(bp);
384 
385 		/* bad CRC means corrupted metadata */
386 		if (error == -EFSBADCRC)
387 			error = -EFSCORRUPTED;
388 		return error;
389 	}
390 #ifdef DEBUG
391 	if (xfs_do_error && !(tp->t_flags & XFS_TRANS_DIRTY)) {
392 		if (xfs_error_target == target) {
393 			if (((xfs_req_num++) % xfs_error_mod) == 0) {
394 				xfs_force_shutdown(tp->t_mountp,
395 						   SHUTDOWN_META_IO_ERROR);
396 				xfs_buf_relse(bp);
397 				xfs_debug(mp, "Returning trans error!");
398 				return -EIO;
399 			}
400 		}
401 	}
402 #endif
403 	if (XFS_FORCED_SHUTDOWN(mp))
404 		goto shutdown_abort;
405 
406 	_xfs_trans_bjoin(tp, bp, 1);
407 	trace_xfs_trans_read_buf(bp->b_fspriv);
408 
409 	*bpp = bp;
410 	return 0;
411 
412 shutdown_abort:
413 	trace_xfs_trans_read_buf_shut(bp, _RET_IP_);
414 	xfs_buf_relse(bp);
415 	*bpp = NULL;
416 	return -EIO;
417 }
418 
419 /*
420  * Release the buffer bp which was previously acquired with one of the
421  * xfs_trans_... buffer allocation routines if the buffer has not
422  * been modified within this transaction.  If the buffer is modified
423  * within this transaction, do decrement the recursion count but do
424  * not release the buffer even if the count goes to 0.  If the buffer is not
425  * modified within the transaction, decrement the recursion count and
426  * release the buffer if the recursion count goes to 0.
427  *
428  * If the buffer is to be released and it was not modified before
429  * this transaction began, then free the buf_log_item associated with it.
430  *
431  * If the transaction pointer is NULL, make this just a normal
432  * brelse() call.
433  */
434 void
435 xfs_trans_brelse(xfs_trans_t	*tp,
436 		 xfs_buf_t	*bp)
437 {
438 	xfs_buf_log_item_t	*bip;
439 
440 	/*
441 	 * Default to a normal brelse() call if the tp is NULL.
442 	 */
443 	if (tp == NULL) {
444 		ASSERT(bp->b_transp == NULL);
445 		xfs_buf_relse(bp);
446 		return;
447 	}
448 
449 	ASSERT(bp->b_transp == tp);
450 	bip = bp->b_fspriv;
451 	ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
452 	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
453 	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
454 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
455 
456 	trace_xfs_trans_brelse(bip);
457 
458 	/*
459 	 * If the release is just for a recursive lock,
460 	 * then decrement the count and return.
461 	 */
462 	if (bip->bli_recur > 0) {
463 		bip->bli_recur--;
464 		return;
465 	}
466 
467 	/*
468 	 * If the buffer is dirty within this transaction, we can't
469 	 * release it until we commit.
470 	 */
471 	if (bip->bli_item.li_desc->lid_flags & XFS_LID_DIRTY)
472 		return;
473 
474 	/*
475 	 * If the buffer has been invalidated, then we can't release
476 	 * it until the transaction commits to disk unless it is re-dirtied
477 	 * as part of this transaction.  This prevents us from pulling
478 	 * the item from the AIL before we should.
479 	 */
480 	if (bip->bli_flags & XFS_BLI_STALE)
481 		return;
482 
483 	ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED));
484 
485 	/*
486 	 * Free up the log item descriptor tracking the released item.
487 	 */
488 	xfs_trans_del_item(&bip->bli_item);
489 
490 	/*
491 	 * Clear the hold flag in the buf log item if it is set.
492 	 * We wouldn't want the next user of the buffer to
493 	 * get confused.
494 	 */
495 	if (bip->bli_flags & XFS_BLI_HOLD) {
496 		bip->bli_flags &= ~XFS_BLI_HOLD;
497 	}
498 
499 	/*
500 	 * Drop our reference to the buf log item.
501 	 */
502 	atomic_dec(&bip->bli_refcount);
503 
504 	/*
505 	 * If the buf item is not tracking data in the log, then
506 	 * we must free it before releasing the buffer back to the
507 	 * free pool.  Before releasing the buffer to the free pool,
508 	 * clear the transaction pointer in b_fsprivate2 to dissolve
509 	 * its relation to this transaction.
510 	 */
511 	if (!xfs_buf_item_dirty(bip)) {
512 /***
513 		ASSERT(bp->b_pincount == 0);
514 ***/
515 		ASSERT(atomic_read(&bip->bli_refcount) == 0);
516 		ASSERT(!(bip->bli_item.li_flags & XFS_LI_IN_AIL));
517 		ASSERT(!(bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF));
518 		xfs_buf_item_relse(bp);
519 	}
520 
521 	bp->b_transp = NULL;
522 	xfs_buf_relse(bp);
523 }
524 
525 /*
526  * Mark the buffer as not needing to be unlocked when the buf item's
527  * iop_unlock() routine is called.  The buffer must already be locked
528  * and associated with the given transaction.
529  */
530 /* ARGSUSED */
531 void
532 xfs_trans_bhold(xfs_trans_t	*tp,
533 		xfs_buf_t	*bp)
534 {
535 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
536 
537 	ASSERT(bp->b_transp == tp);
538 	ASSERT(bip != NULL);
539 	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
540 	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
541 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
542 
543 	bip->bli_flags |= XFS_BLI_HOLD;
544 	trace_xfs_trans_bhold(bip);
545 }
546 
547 /*
548  * Cancel the previous buffer hold request made on this buffer
549  * for this transaction.
550  */
551 void
552 xfs_trans_bhold_release(xfs_trans_t	*tp,
553 			xfs_buf_t	*bp)
554 {
555 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
556 
557 	ASSERT(bp->b_transp == tp);
558 	ASSERT(bip != NULL);
559 	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
560 	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
561 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
562 	ASSERT(bip->bli_flags & XFS_BLI_HOLD);
563 
564 	bip->bli_flags &= ~XFS_BLI_HOLD;
565 	trace_xfs_trans_bhold_release(bip);
566 }
567 
568 /*
569  * This is called to mark bytes first through last inclusive of the given
570  * buffer as needing to be logged when the transaction is committed.
571  * The buffer must already be associated with the given transaction.
572  *
573  * First and last are numbers relative to the beginning of this buffer,
574  * so the first byte in the buffer is numbered 0 regardless of the
575  * value of b_blkno.
576  */
577 void
578 xfs_trans_log_buf(xfs_trans_t	*tp,
579 		  xfs_buf_t	*bp,
580 		  uint		first,
581 		  uint		last)
582 {
583 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
584 
585 	ASSERT(bp->b_transp == tp);
586 	ASSERT(bip != NULL);
587 	ASSERT(first <= last && last < BBTOB(bp->b_length));
588 	ASSERT(bp->b_iodone == NULL ||
589 	       bp->b_iodone == xfs_buf_iodone_callbacks);
590 
591 	/*
592 	 * Mark the buffer as needing to be written out eventually,
593 	 * and set its iodone function to remove the buffer's buf log
594 	 * item from the AIL and free it when the buffer is flushed
595 	 * to disk.  See xfs_buf_attach_iodone() for more details
596 	 * on li_cb and xfs_buf_iodone_callbacks().
597 	 * If we end up aborting this transaction, we trap this buffer
598 	 * inside the b_bdstrat callback so that this won't get written to
599 	 * disk.
600 	 */
601 	XFS_BUF_DONE(bp);
602 
603 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
604 	bp->b_iodone = xfs_buf_iodone_callbacks;
605 	bip->bli_item.li_cb = xfs_buf_iodone;
606 
607 	trace_xfs_trans_log_buf(bip);
608 
609 	/*
610 	 * If we invalidated the buffer within this transaction, then
611 	 * cancel the invalidation now that we're dirtying the buffer
612 	 * again.  There are no races with the code in xfs_buf_item_unpin(),
613 	 * because we have a reference to the buffer this entire time.
614 	 */
615 	if (bip->bli_flags & XFS_BLI_STALE) {
616 		bip->bli_flags &= ~XFS_BLI_STALE;
617 		ASSERT(XFS_BUF_ISSTALE(bp));
618 		XFS_BUF_UNSTALE(bp);
619 		bip->__bli_format.blf_flags &= ~XFS_BLF_CANCEL;
620 	}
621 
622 	tp->t_flags |= XFS_TRANS_DIRTY;
623 	bip->bli_item.li_desc->lid_flags |= XFS_LID_DIRTY;
624 
625 	/*
626 	 * If we have an ordered buffer we are not logging any dirty range but
627 	 * it still needs to be marked dirty and that it has been logged.
628 	 */
629 	bip->bli_flags |= XFS_BLI_DIRTY | XFS_BLI_LOGGED;
630 	if (!(bip->bli_flags & XFS_BLI_ORDERED))
631 		xfs_buf_item_log(bip, first, last);
632 }
633 
634 
635 /*
636  * Invalidate a buffer that is being used within a transaction.
637  *
638  * Typically this is because the blocks in the buffer are being freed, so we
639  * need to prevent it from being written out when we're done.  Allowing it
640  * to be written again might overwrite data in the free blocks if they are
641  * reallocated to a file.
642  *
643  * We prevent the buffer from being written out by marking it stale.  We can't
644  * get rid of the buf log item at this point because the buffer may still be
645  * pinned by another transaction.  If that is the case, then we'll wait until
646  * the buffer is committed to disk for the last time (we can tell by the ref
647  * count) and free it in xfs_buf_item_unpin().  Until that happens we will
648  * keep the buffer locked so that the buffer and buf log item are not reused.
649  *
650  * We also set the XFS_BLF_CANCEL flag in the buf log format structure and log
651  * the buf item.  This will be used at recovery time to determine that copies
652  * of the buffer in the log before this should not be replayed.
653  *
654  * We mark the item descriptor and the transaction dirty so that we'll hold
655  * the buffer until after the commit.
656  *
657  * Since we're invalidating the buffer, we also clear the state about which
658  * parts of the buffer have been logged.  We also clear the flag indicating
659  * that this is an inode buffer since the data in the buffer will no longer
660  * be valid.
661  *
662  * We set the stale bit in the buffer as well since we're getting rid of it.
663  */
664 void
665 xfs_trans_binval(
666 	xfs_trans_t	*tp,
667 	xfs_buf_t	*bp)
668 {
669 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
670 	int			i;
671 
672 	ASSERT(bp->b_transp == tp);
673 	ASSERT(bip != NULL);
674 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
675 
676 	trace_xfs_trans_binval(bip);
677 
678 	if (bip->bli_flags & XFS_BLI_STALE) {
679 		/*
680 		 * If the buffer is already invalidated, then
681 		 * just return.
682 		 */
683 		ASSERT(XFS_BUF_ISSTALE(bp));
684 		ASSERT(!(bip->bli_flags & (XFS_BLI_LOGGED | XFS_BLI_DIRTY)));
685 		ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_INODE_BUF));
686 		ASSERT(!(bip->__bli_format.blf_flags & XFS_BLFT_MASK));
687 		ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
688 		ASSERT(bip->bli_item.li_desc->lid_flags & XFS_LID_DIRTY);
689 		ASSERT(tp->t_flags & XFS_TRANS_DIRTY);
690 		return;
691 	}
692 
693 	xfs_buf_stale(bp);
694 
695 	bip->bli_flags |= XFS_BLI_STALE;
696 	bip->bli_flags &= ~(XFS_BLI_INODE_BUF | XFS_BLI_LOGGED | XFS_BLI_DIRTY);
697 	bip->__bli_format.blf_flags &= ~XFS_BLF_INODE_BUF;
698 	bip->__bli_format.blf_flags |= XFS_BLF_CANCEL;
699 	bip->__bli_format.blf_flags &= ~XFS_BLFT_MASK;
700 	for (i = 0; i < bip->bli_format_count; i++) {
701 		memset(bip->bli_formats[i].blf_data_map, 0,
702 		       (bip->bli_formats[i].blf_map_size * sizeof(uint)));
703 	}
704 	bip->bli_item.li_desc->lid_flags |= XFS_LID_DIRTY;
705 	tp->t_flags |= XFS_TRANS_DIRTY;
706 }
707 
708 /*
709  * This call is used to indicate that the buffer contains on-disk inodes which
710  * must be handled specially during recovery.  They require special handling
711  * because only the di_next_unlinked from the inodes in the buffer should be
712  * recovered.  The rest of the data in the buffer is logged via the inodes
713  * themselves.
714  *
715  * All we do is set the XFS_BLI_INODE_BUF flag in the items flags so it can be
716  * transferred to the buffer's log format structure so that we'll know what to
717  * do at recovery time.
718  */
719 void
720 xfs_trans_inode_buf(
721 	xfs_trans_t	*tp,
722 	xfs_buf_t	*bp)
723 {
724 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
725 
726 	ASSERT(bp->b_transp == tp);
727 	ASSERT(bip != NULL);
728 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
729 
730 	bip->bli_flags |= XFS_BLI_INODE_BUF;
731 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
732 }
733 
734 /*
735  * This call is used to indicate that the buffer is going to
736  * be staled and was an inode buffer. This means it gets
737  * special processing during unpin - where any inodes
738  * associated with the buffer should be removed from ail.
739  * There is also special processing during recovery,
740  * any replay of the inodes in the buffer needs to be
741  * prevented as the buffer may have been reused.
742  */
743 void
744 xfs_trans_stale_inode_buf(
745 	xfs_trans_t	*tp,
746 	xfs_buf_t	*bp)
747 {
748 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
749 
750 	ASSERT(bp->b_transp == tp);
751 	ASSERT(bip != NULL);
752 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
753 
754 	bip->bli_flags |= XFS_BLI_STALE_INODE;
755 	bip->bli_item.li_cb = xfs_buf_iodone;
756 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
757 }
758 
759 /*
760  * Mark the buffer as being one which contains newly allocated
761  * inodes.  We need to make sure that even if this buffer is
762  * relogged as an 'inode buf' we still recover all of the inode
763  * images in the face of a crash.  This works in coordination with
764  * xfs_buf_item_committed() to ensure that the buffer remains in the
765  * AIL at its original location even after it has been relogged.
766  */
767 /* ARGSUSED */
768 void
769 xfs_trans_inode_alloc_buf(
770 	xfs_trans_t	*tp,
771 	xfs_buf_t	*bp)
772 {
773 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
774 
775 	ASSERT(bp->b_transp == tp);
776 	ASSERT(bip != NULL);
777 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
778 
779 	bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF;
780 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
781 }
782 
783 /*
784  * Mark the buffer as ordered for this transaction. This means
785  * that the contents of the buffer are not recorded in the transaction
786  * but it is tracked in the AIL as though it was. This allows us
787  * to record logical changes in transactions rather than the physical
788  * changes we make to the buffer without changing writeback ordering
789  * constraints of metadata buffers.
790  */
791 void
792 xfs_trans_ordered_buf(
793 	struct xfs_trans	*tp,
794 	struct xfs_buf		*bp)
795 {
796 	struct xfs_buf_log_item	*bip = bp->b_fspriv;
797 
798 	ASSERT(bp->b_transp == tp);
799 	ASSERT(bip != NULL);
800 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
801 
802 	bip->bli_flags |= XFS_BLI_ORDERED;
803 	trace_xfs_buf_item_ordered(bip);
804 }
805 
806 /*
807  * Set the type of the buffer for log recovery so that it can correctly identify
808  * and hence attach the correct buffer ops to the buffer after replay.
809  */
810 void
811 xfs_trans_buf_set_type(
812 	struct xfs_trans	*tp,
813 	struct xfs_buf		*bp,
814 	enum xfs_blft		type)
815 {
816 	struct xfs_buf_log_item	*bip = bp->b_fspriv;
817 
818 	if (!tp)
819 		return;
820 
821 	ASSERT(bp->b_transp == tp);
822 	ASSERT(bip != NULL);
823 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
824 
825 	xfs_blft_to_flags(&bip->__bli_format, type);
826 }
827 
828 void
829 xfs_trans_buf_copy_type(
830 	struct xfs_buf		*dst_bp,
831 	struct xfs_buf		*src_bp)
832 {
833 	struct xfs_buf_log_item	*sbip = src_bp->b_fspriv;
834 	struct xfs_buf_log_item	*dbip = dst_bp->b_fspriv;
835 	enum xfs_blft		type;
836 
837 	type = xfs_blft_from_flags(&sbip->__bli_format);
838 	xfs_blft_to_flags(&dbip->__bli_format, type);
839 }
840 
841 /*
842  * Similar to xfs_trans_inode_buf(), this marks the buffer as a cluster of
843  * dquots. However, unlike in inode buffer recovery, dquot buffers get
844  * recovered in their entirety. (Hence, no XFS_BLI_DQUOT_ALLOC_BUF flag).
845  * The only thing that makes dquot buffers different from regular
846  * buffers is that we must not replay dquot bufs when recovering
847  * if a _corresponding_ quotaoff has happened. We also have to distinguish
848  * between usr dquot bufs and grp dquot bufs, because usr and grp quotas
849  * can be turned off independently.
850  */
851 /* ARGSUSED */
852 void
853 xfs_trans_dquot_buf(
854 	xfs_trans_t	*tp,
855 	xfs_buf_t	*bp,
856 	uint		type)
857 {
858 	struct xfs_buf_log_item	*bip = bp->b_fspriv;
859 
860 	ASSERT(type == XFS_BLF_UDQUOT_BUF ||
861 	       type == XFS_BLF_PDQUOT_BUF ||
862 	       type == XFS_BLF_GDQUOT_BUF);
863 
864 	bip->__bli_format.blf_flags |= type;
865 
866 	switch (type) {
867 	case XFS_BLF_UDQUOT_BUF:
868 		type = XFS_BLFT_UDQUOT_BUF;
869 		break;
870 	case XFS_BLF_PDQUOT_BUF:
871 		type = XFS_BLFT_PDQUOT_BUF;
872 		break;
873 	case XFS_BLF_GDQUOT_BUF:
874 		type = XFS_BLFT_GDQUOT_BUF;
875 		break;
876 	default:
877 		type = XFS_BLFT_UNKNOWN_BUF;
878 		break;
879 	}
880 
881 	xfs_trans_buf_set_type(tp, bp, type);
882 }
883