xref: /linux/fs/xfs/xfs_trans_buf.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 	/*
209 	 * If the superblock buffer already has this transaction
210 	 * pointer in its b_fsprivate2 field, then we know we already
211 	 * have it locked.  In this case we just increment the lock
212 	 * recursion count and return the buffer to the caller.
213 	 */
214 	bp = mp->m_sb_bp;
215 	if (bp->b_transp == tp) {
216 		bip = bp->b_fspriv;
217 		ASSERT(bip != NULL);
218 		ASSERT(atomic_read(&bip->bli_refcount) > 0);
219 		bip->bli_recur++;
220 		trace_xfs_trans_getsb_recur(bip);
221 		return (bp);
222 	}
223 
224 	bp = xfs_getsb(mp, flags);
225 	if (bp == NULL)
226 		return NULL;
227 
228 	_xfs_trans_bjoin(tp, bp, 1);
229 	trace_xfs_trans_getsb(bp->b_fspriv);
230 	return (bp);
231 }
232 
233 #ifdef DEBUG
234 xfs_buftarg_t *xfs_error_target;
235 int	xfs_do_error;
236 int	xfs_req_num;
237 int	xfs_error_mod = 33;
238 #endif
239 
240 /*
241  * Get and lock the buffer for the caller if it is not already
242  * locked within the given transaction.  If it has not yet been
243  * read in, read it from disk. If it is already locked
244  * within the transaction and already read in, just increment its
245  * lock recursion count and return a pointer to it.
246  *
247  * If the transaction pointer is NULL, make this just a normal
248  * read_buf() call.
249  */
250 int
251 xfs_trans_read_buf_map(
252 	struct xfs_mount	*mp,
253 	struct xfs_trans	*tp,
254 	struct xfs_buftarg	*target,
255 	struct xfs_buf_map	*map,
256 	int			nmaps,
257 	xfs_buf_flags_t		flags,
258 	struct xfs_buf		**bpp,
259 	const struct xfs_buf_ops *ops)
260 {
261 	xfs_buf_t		*bp;
262 	xfs_buf_log_item_t	*bip;
263 	int			error;
264 
265 	*bpp = NULL;
266 	if (!tp) {
267 		bp = xfs_buf_read_map(target, map, nmaps, flags, ops);
268 		if (!bp)
269 			return (flags & XBF_TRYLOCK) ?
270 					EAGAIN : XFS_ERROR(ENOMEM);
271 
272 		if (bp->b_error) {
273 			error = bp->b_error;
274 			xfs_buf_ioerror_alert(bp, __func__);
275 			XFS_BUF_UNDONE(bp);
276 			xfs_buf_stale(bp);
277 			xfs_buf_relse(bp);
278 			return error;
279 		}
280 #ifdef DEBUG
281 		if (xfs_do_error) {
282 			if (xfs_error_target == target) {
283 				if (((xfs_req_num++) % xfs_error_mod) == 0) {
284 					xfs_buf_relse(bp);
285 					xfs_debug(mp, "Returning error!");
286 					return XFS_ERROR(EIO);
287 				}
288 			}
289 		}
290 #endif
291 		if (XFS_FORCED_SHUTDOWN(mp))
292 			goto shutdown_abort;
293 		*bpp = bp;
294 		return 0;
295 	}
296 
297 	/*
298 	 * If we find the buffer in the cache with this transaction
299 	 * pointer in its b_fsprivate2 field, then we know we already
300 	 * have it locked.  If it is already read in we just increment
301 	 * the lock recursion count and return the buffer to the caller.
302 	 * If the buffer is not yet read in, then we read it in, increment
303 	 * the lock recursion count, and return it to the caller.
304 	 */
305 	bp = xfs_trans_buf_item_match(tp, target, map, nmaps);
306 	if (bp != NULL) {
307 		ASSERT(xfs_buf_islocked(bp));
308 		ASSERT(bp->b_transp == tp);
309 		ASSERT(bp->b_fspriv != NULL);
310 		ASSERT(!bp->b_error);
311 		if (!(XFS_BUF_ISDONE(bp))) {
312 			trace_xfs_trans_read_buf_io(bp, _RET_IP_);
313 			ASSERT(!XFS_BUF_ISASYNC(bp));
314 			ASSERT(bp->b_iodone == NULL);
315 			XFS_BUF_READ(bp);
316 			bp->b_ops = ops;
317 
318 			/*
319 			 * XXX(hch): clean up the error handling here to be less
320 			 * of a mess..
321 			 */
322 			if (XFS_FORCED_SHUTDOWN(mp)) {
323 				trace_xfs_bdstrat_shut(bp, _RET_IP_);
324 				xfs_bioerror_relse(bp);
325 			} else {
326 				xfs_buf_iorequest(bp);
327 			}
328 
329 			error = xfs_buf_iowait(bp);
330 			if (error) {
331 				xfs_buf_ioerror_alert(bp, __func__);
332 				xfs_buf_relse(bp);
333 				/*
334 				 * We can gracefully recover from most read
335 				 * errors. Ones we can't are those that happen
336 				 * after the transaction's already dirty.
337 				 */
338 				if (tp->t_flags & XFS_TRANS_DIRTY)
339 					xfs_force_shutdown(tp->t_mountp,
340 							SHUTDOWN_META_IO_ERROR);
341 				return error;
342 			}
343 		}
344 		/*
345 		 * We never locked this buf ourselves, so we shouldn't
346 		 * brelse it either. Just get out.
347 		 */
348 		if (XFS_FORCED_SHUTDOWN(mp)) {
349 			trace_xfs_trans_read_buf_shut(bp, _RET_IP_);
350 			*bpp = NULL;
351 			return XFS_ERROR(EIO);
352 		}
353 
354 
355 		bip = bp->b_fspriv;
356 		bip->bli_recur++;
357 
358 		ASSERT(atomic_read(&bip->bli_refcount) > 0);
359 		trace_xfs_trans_read_buf_recur(bip);
360 		*bpp = bp;
361 		return 0;
362 	}
363 
364 	bp = xfs_buf_read_map(target, map, nmaps, flags, ops);
365 	if (bp == NULL) {
366 		*bpp = NULL;
367 		return (flags & XBF_TRYLOCK) ?
368 					0 : XFS_ERROR(ENOMEM);
369 	}
370 	if (bp->b_error) {
371 		error = bp->b_error;
372 		xfs_buf_stale(bp);
373 		XFS_BUF_DONE(bp);
374 		xfs_buf_ioerror_alert(bp, __func__);
375 		if (tp->t_flags & XFS_TRANS_DIRTY)
376 			xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR);
377 		xfs_buf_relse(bp);
378 		return error;
379 	}
380 #ifdef DEBUG
381 	if (xfs_do_error && !(tp->t_flags & XFS_TRANS_DIRTY)) {
382 		if (xfs_error_target == target) {
383 			if (((xfs_req_num++) % xfs_error_mod) == 0) {
384 				xfs_force_shutdown(tp->t_mountp,
385 						   SHUTDOWN_META_IO_ERROR);
386 				xfs_buf_relse(bp);
387 				xfs_debug(mp, "Returning trans error!");
388 				return XFS_ERROR(EIO);
389 			}
390 		}
391 	}
392 #endif
393 	if (XFS_FORCED_SHUTDOWN(mp))
394 		goto shutdown_abort;
395 
396 	_xfs_trans_bjoin(tp, bp, 1);
397 	trace_xfs_trans_read_buf(bp->b_fspriv);
398 
399 	*bpp = bp;
400 	return 0;
401 
402 shutdown_abort:
403 	trace_xfs_trans_read_buf_shut(bp, _RET_IP_);
404 	xfs_buf_relse(bp);
405 	*bpp = NULL;
406 	return XFS_ERROR(EIO);
407 }
408 
409 /*
410  * Release the buffer bp which was previously acquired with one of the
411  * xfs_trans_... buffer allocation routines if the buffer has not
412  * been modified within this transaction.  If the buffer is modified
413  * within this transaction, do decrement the recursion count but do
414  * not release the buffer even if the count goes to 0.  If the buffer is not
415  * modified within the transaction, decrement the recursion count and
416  * release the buffer if the recursion count goes to 0.
417  *
418  * If the buffer is to be released and it was not modified before
419  * this transaction began, then free the buf_log_item associated with it.
420  *
421  * If the transaction pointer is NULL, make this just a normal
422  * brelse() call.
423  */
424 void
425 xfs_trans_brelse(xfs_trans_t	*tp,
426 		 xfs_buf_t	*bp)
427 {
428 	xfs_buf_log_item_t	*bip;
429 
430 	/*
431 	 * Default to a normal brelse() call if the tp is NULL.
432 	 */
433 	if (tp == NULL) {
434 		ASSERT(bp->b_transp == NULL);
435 		xfs_buf_relse(bp);
436 		return;
437 	}
438 
439 	ASSERT(bp->b_transp == tp);
440 	bip = bp->b_fspriv;
441 	ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
442 	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
443 	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
444 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
445 
446 	trace_xfs_trans_brelse(bip);
447 
448 	/*
449 	 * If the release is just for a recursive lock,
450 	 * then decrement the count and return.
451 	 */
452 	if (bip->bli_recur > 0) {
453 		bip->bli_recur--;
454 		return;
455 	}
456 
457 	/*
458 	 * If the buffer is dirty within this transaction, we can't
459 	 * release it until we commit.
460 	 */
461 	if (bip->bli_item.li_desc->lid_flags & XFS_LID_DIRTY)
462 		return;
463 
464 	/*
465 	 * If the buffer has been invalidated, then we can't release
466 	 * it until the transaction commits to disk unless it is re-dirtied
467 	 * as part of this transaction.  This prevents us from pulling
468 	 * the item from the AIL before we should.
469 	 */
470 	if (bip->bli_flags & XFS_BLI_STALE)
471 		return;
472 
473 	ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED));
474 
475 	/*
476 	 * Free up the log item descriptor tracking the released item.
477 	 */
478 	xfs_trans_del_item(&bip->bli_item);
479 
480 	/*
481 	 * Clear the hold flag in the buf log item if it is set.
482 	 * We wouldn't want the next user of the buffer to
483 	 * get confused.
484 	 */
485 	if (bip->bli_flags & XFS_BLI_HOLD) {
486 		bip->bli_flags &= ~XFS_BLI_HOLD;
487 	}
488 
489 	/*
490 	 * Drop our reference to the buf log item.
491 	 */
492 	atomic_dec(&bip->bli_refcount);
493 
494 	/*
495 	 * If the buf item is not tracking data in the log, then
496 	 * we must free it before releasing the buffer back to the
497 	 * free pool.  Before releasing the buffer to the free pool,
498 	 * clear the transaction pointer in b_fsprivate2 to dissolve
499 	 * its relation to this transaction.
500 	 */
501 	if (!xfs_buf_item_dirty(bip)) {
502 /***
503 		ASSERT(bp->b_pincount == 0);
504 ***/
505 		ASSERT(atomic_read(&bip->bli_refcount) == 0);
506 		ASSERT(!(bip->bli_item.li_flags & XFS_LI_IN_AIL));
507 		ASSERT(!(bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF));
508 		xfs_buf_item_relse(bp);
509 	}
510 
511 	bp->b_transp = NULL;
512 	xfs_buf_relse(bp);
513 }
514 
515 /*
516  * Mark the buffer as not needing to be unlocked when the buf item's
517  * iop_unlock() routine is called.  The buffer must already be locked
518  * and associated with the given transaction.
519  */
520 /* ARGSUSED */
521 void
522 xfs_trans_bhold(xfs_trans_t	*tp,
523 		xfs_buf_t	*bp)
524 {
525 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
526 
527 	ASSERT(bp->b_transp == tp);
528 	ASSERT(bip != NULL);
529 	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
530 	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
531 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
532 
533 	bip->bli_flags |= XFS_BLI_HOLD;
534 	trace_xfs_trans_bhold(bip);
535 }
536 
537 /*
538  * Cancel the previous buffer hold request made on this buffer
539  * for this transaction.
540  */
541 void
542 xfs_trans_bhold_release(xfs_trans_t	*tp,
543 			xfs_buf_t	*bp)
544 {
545 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
546 
547 	ASSERT(bp->b_transp == tp);
548 	ASSERT(bip != NULL);
549 	ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
550 	ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
551 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
552 	ASSERT(bip->bli_flags & XFS_BLI_HOLD);
553 
554 	bip->bli_flags &= ~XFS_BLI_HOLD;
555 	trace_xfs_trans_bhold_release(bip);
556 }
557 
558 /*
559  * This is called to mark bytes first through last inclusive of the given
560  * buffer as needing to be logged when the transaction is committed.
561  * The buffer must already be associated with the given transaction.
562  *
563  * First and last are numbers relative to the beginning of this buffer,
564  * so the first byte in the buffer is numbered 0 regardless of the
565  * value of b_blkno.
566  */
567 void
568 xfs_trans_log_buf(xfs_trans_t	*tp,
569 		  xfs_buf_t	*bp,
570 		  uint		first,
571 		  uint		last)
572 {
573 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
574 
575 	ASSERT(bp->b_transp == tp);
576 	ASSERT(bip != NULL);
577 	ASSERT(first <= last && last < BBTOB(bp->b_length));
578 	ASSERT(bp->b_iodone == NULL ||
579 	       bp->b_iodone == xfs_buf_iodone_callbacks);
580 
581 	/*
582 	 * Mark the buffer as needing to be written out eventually,
583 	 * and set its iodone function to remove the buffer's buf log
584 	 * item from the AIL and free it when the buffer is flushed
585 	 * to disk.  See xfs_buf_attach_iodone() for more details
586 	 * on li_cb and xfs_buf_iodone_callbacks().
587 	 * If we end up aborting this transaction, we trap this buffer
588 	 * inside the b_bdstrat callback so that this won't get written to
589 	 * disk.
590 	 */
591 	XFS_BUF_DONE(bp);
592 
593 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
594 	bp->b_iodone = xfs_buf_iodone_callbacks;
595 	bip->bli_item.li_cb = xfs_buf_iodone;
596 
597 	trace_xfs_trans_log_buf(bip);
598 
599 	/*
600 	 * If we invalidated the buffer within this transaction, then
601 	 * cancel the invalidation now that we're dirtying the buffer
602 	 * again.  There are no races with the code in xfs_buf_item_unpin(),
603 	 * because we have a reference to the buffer this entire time.
604 	 */
605 	if (bip->bli_flags & XFS_BLI_STALE) {
606 		bip->bli_flags &= ~XFS_BLI_STALE;
607 		ASSERT(XFS_BUF_ISSTALE(bp));
608 		XFS_BUF_UNSTALE(bp);
609 		bip->__bli_format.blf_flags &= ~XFS_BLF_CANCEL;
610 	}
611 
612 	tp->t_flags |= XFS_TRANS_DIRTY;
613 	bip->bli_item.li_desc->lid_flags |= XFS_LID_DIRTY;
614 
615 	/*
616 	 * If we have an ordered buffer we are not logging any dirty range but
617 	 * it still needs to be marked dirty and that it has been logged.
618 	 */
619 	bip->bli_flags |= XFS_BLI_DIRTY | XFS_BLI_LOGGED;
620 	if (!(bip->bli_flags & XFS_BLI_ORDERED))
621 		xfs_buf_item_log(bip, first, last);
622 }
623 
624 
625 /*
626  * Invalidate a buffer that is being used within a transaction.
627  *
628  * Typically this is because the blocks in the buffer are being freed, so we
629  * need to prevent it from being written out when we're done.  Allowing it
630  * to be written again might overwrite data in the free blocks if they are
631  * reallocated to a file.
632  *
633  * We prevent the buffer from being written out by marking it stale.  We can't
634  * get rid of the buf log item at this point because the buffer may still be
635  * pinned by another transaction.  If that is the case, then we'll wait until
636  * the buffer is committed to disk for the last time (we can tell by the ref
637  * count) and free it in xfs_buf_item_unpin().  Until that happens we will
638  * keep the buffer locked so that the buffer and buf log item are not reused.
639  *
640  * We also set the XFS_BLF_CANCEL flag in the buf log format structure and log
641  * the buf item.  This will be used at recovery time to determine that copies
642  * of the buffer in the log before this should not be replayed.
643  *
644  * We mark the item descriptor and the transaction dirty so that we'll hold
645  * the buffer until after the commit.
646  *
647  * Since we're invalidating the buffer, we also clear the state about which
648  * parts of the buffer have been logged.  We also clear the flag indicating
649  * that this is an inode buffer since the data in the buffer will no longer
650  * be valid.
651  *
652  * We set the stale bit in the buffer as well since we're getting rid of it.
653  */
654 void
655 xfs_trans_binval(
656 	xfs_trans_t	*tp,
657 	xfs_buf_t	*bp)
658 {
659 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
660 	int			i;
661 
662 	ASSERT(bp->b_transp == tp);
663 	ASSERT(bip != NULL);
664 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
665 
666 	trace_xfs_trans_binval(bip);
667 
668 	if (bip->bli_flags & XFS_BLI_STALE) {
669 		/*
670 		 * If the buffer is already invalidated, then
671 		 * just return.
672 		 */
673 		ASSERT(XFS_BUF_ISSTALE(bp));
674 		ASSERT(!(bip->bli_flags & (XFS_BLI_LOGGED | XFS_BLI_DIRTY)));
675 		ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_INODE_BUF));
676 		ASSERT(!(bip->__bli_format.blf_flags & XFS_BLFT_MASK));
677 		ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
678 		ASSERT(bip->bli_item.li_desc->lid_flags & XFS_LID_DIRTY);
679 		ASSERT(tp->t_flags & XFS_TRANS_DIRTY);
680 		return;
681 	}
682 
683 	xfs_buf_stale(bp);
684 
685 	bip->bli_flags |= XFS_BLI_STALE;
686 	bip->bli_flags &= ~(XFS_BLI_INODE_BUF | XFS_BLI_LOGGED | XFS_BLI_DIRTY);
687 	bip->__bli_format.blf_flags &= ~XFS_BLF_INODE_BUF;
688 	bip->__bli_format.blf_flags |= XFS_BLF_CANCEL;
689 	bip->__bli_format.blf_flags &= ~XFS_BLFT_MASK;
690 	for (i = 0; i < bip->bli_format_count; i++) {
691 		memset(bip->bli_formats[i].blf_data_map, 0,
692 		       (bip->bli_formats[i].blf_map_size * sizeof(uint)));
693 	}
694 	bip->bli_item.li_desc->lid_flags |= XFS_LID_DIRTY;
695 	tp->t_flags |= XFS_TRANS_DIRTY;
696 }
697 
698 /*
699  * This call is used to indicate that the buffer contains on-disk inodes which
700  * must be handled specially during recovery.  They require special handling
701  * because only the di_next_unlinked from the inodes in the buffer should be
702  * recovered.  The rest of the data in the buffer is logged via the inodes
703  * themselves.
704  *
705  * All we do is set the XFS_BLI_INODE_BUF flag in the items flags so it can be
706  * transferred to the buffer's log format structure so that we'll know what to
707  * do at recovery time.
708  */
709 void
710 xfs_trans_inode_buf(
711 	xfs_trans_t	*tp,
712 	xfs_buf_t	*bp)
713 {
714 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
715 
716 	ASSERT(bp->b_transp == tp);
717 	ASSERT(bip != NULL);
718 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
719 
720 	bip->bli_flags |= XFS_BLI_INODE_BUF;
721 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
722 }
723 
724 /*
725  * This call is used to indicate that the buffer is going to
726  * be staled and was an inode buffer. This means it gets
727  * special processing during unpin - where any inodes
728  * associated with the buffer should be removed from ail.
729  * There is also special processing during recovery,
730  * any replay of the inodes in the buffer needs to be
731  * prevented as the buffer may have been reused.
732  */
733 void
734 xfs_trans_stale_inode_buf(
735 	xfs_trans_t	*tp,
736 	xfs_buf_t	*bp)
737 {
738 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
739 
740 	ASSERT(bp->b_transp == tp);
741 	ASSERT(bip != NULL);
742 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
743 
744 	bip->bli_flags |= XFS_BLI_STALE_INODE;
745 	bip->bli_item.li_cb = xfs_buf_iodone;
746 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
747 }
748 
749 /*
750  * Mark the buffer as being one which contains newly allocated
751  * inodes.  We need to make sure that even if this buffer is
752  * relogged as an 'inode buf' we still recover all of the inode
753  * images in the face of a crash.  This works in coordination with
754  * xfs_buf_item_committed() to ensure that the buffer remains in the
755  * AIL at its original location even after it has been relogged.
756  */
757 /* ARGSUSED */
758 void
759 xfs_trans_inode_alloc_buf(
760 	xfs_trans_t	*tp,
761 	xfs_buf_t	*bp)
762 {
763 	xfs_buf_log_item_t	*bip = bp->b_fspriv;
764 
765 	ASSERT(bp->b_transp == tp);
766 	ASSERT(bip != NULL);
767 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
768 
769 	bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF;
770 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
771 }
772 
773 /*
774  * Mark the buffer as ordered for this transaction. This means
775  * that the contents of the buffer are not recorded in the transaction
776  * but it is tracked in the AIL as though it was. This allows us
777  * to record logical changes in transactions rather than the physical
778  * changes we make to the buffer without changing writeback ordering
779  * constraints of metadata buffers.
780  */
781 void
782 xfs_trans_ordered_buf(
783 	struct xfs_trans	*tp,
784 	struct xfs_buf		*bp)
785 {
786 	struct xfs_buf_log_item	*bip = bp->b_fspriv;
787 
788 	ASSERT(bp->b_transp == tp);
789 	ASSERT(bip != NULL);
790 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
791 
792 	bip->bli_flags |= XFS_BLI_ORDERED;
793 	trace_xfs_buf_item_ordered(bip);
794 }
795 
796 /*
797  * Set the type of the buffer for log recovery so that it can correctly identify
798  * and hence attach the correct buffer ops to the buffer after replay.
799  */
800 void
801 xfs_trans_buf_set_type(
802 	struct xfs_trans	*tp,
803 	struct xfs_buf		*bp,
804 	enum xfs_blft		type)
805 {
806 	struct xfs_buf_log_item	*bip = bp->b_fspriv;
807 
808 	if (!tp)
809 		return;
810 
811 	ASSERT(bp->b_transp == tp);
812 	ASSERT(bip != NULL);
813 	ASSERT(atomic_read(&bip->bli_refcount) > 0);
814 
815 	xfs_blft_to_flags(&bip->__bli_format, type);
816 }
817 
818 void
819 xfs_trans_buf_copy_type(
820 	struct xfs_buf		*dst_bp,
821 	struct xfs_buf		*src_bp)
822 {
823 	struct xfs_buf_log_item	*sbip = src_bp->b_fspriv;
824 	struct xfs_buf_log_item	*dbip = dst_bp->b_fspriv;
825 	enum xfs_blft		type;
826 
827 	type = xfs_blft_from_flags(&sbip->__bli_format);
828 	xfs_blft_to_flags(&dbip->__bli_format, type);
829 }
830 
831 /*
832  * Similar to xfs_trans_inode_buf(), this marks the buffer as a cluster of
833  * dquots. However, unlike in inode buffer recovery, dquot buffers get
834  * recovered in their entirety. (Hence, no XFS_BLI_DQUOT_ALLOC_BUF flag).
835  * The only thing that makes dquot buffers different from regular
836  * buffers is that we must not replay dquot bufs when recovering
837  * if a _corresponding_ quotaoff has happened. We also have to distinguish
838  * between usr dquot bufs and grp dquot bufs, because usr and grp quotas
839  * can be turned off independently.
840  */
841 /* ARGSUSED */
842 void
843 xfs_trans_dquot_buf(
844 	xfs_trans_t	*tp,
845 	xfs_buf_t	*bp,
846 	uint		type)
847 {
848 	struct xfs_buf_log_item	*bip = bp->b_fspriv;
849 
850 	ASSERT(type == XFS_BLF_UDQUOT_BUF ||
851 	       type == XFS_BLF_PDQUOT_BUF ||
852 	       type == XFS_BLF_GDQUOT_BUF);
853 
854 	bip->__bli_format.blf_flags |= type;
855 
856 	switch (type) {
857 	case XFS_BLF_UDQUOT_BUF:
858 		type = XFS_BLFT_UDQUOT_BUF;
859 		break;
860 	case XFS_BLF_PDQUOT_BUF:
861 		type = XFS_BLFT_PDQUOT_BUF;
862 		break;
863 	case XFS_BLF_GDQUOT_BUF:
864 		type = XFS_BLFT_GDQUOT_BUF;
865 		break;
866 	default:
867 		type = XFS_BLFT_UNKNOWN_BUF;
868 		break;
869 	}
870 
871 	xfs_trans_buf_set_type(tp, bp, type);
872 }
873