xref: /linux/fs/xfs/xfs_extfree_item.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
1 /*
2  * Copyright (c) 2000-2001,2005 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_log_format.h"
21 #include "xfs_trans_resv.h"
22 #include "xfs_sb.h"
23 #include "xfs_ag.h"
24 #include "xfs_mount.h"
25 #include "xfs_trans.h"
26 #include "xfs_trans_priv.h"
27 #include "xfs_buf_item.h"
28 #include "xfs_extfree_item.h"
29 #include "xfs_log.h"
30 
31 
32 kmem_zone_t	*xfs_efi_zone;
33 kmem_zone_t	*xfs_efd_zone;
34 
35 static inline struct xfs_efi_log_item *EFI_ITEM(struct xfs_log_item *lip)
36 {
37 	return container_of(lip, struct xfs_efi_log_item, efi_item);
38 }
39 
40 void
41 xfs_efi_item_free(
42 	struct xfs_efi_log_item	*efip)
43 {
44 	if (efip->efi_format.efi_nextents > XFS_EFI_MAX_FAST_EXTENTS)
45 		kmem_free(efip);
46 	else
47 		kmem_zone_free(xfs_efi_zone, efip);
48 }
49 
50 /*
51  * Freeing the efi requires that we remove it from the AIL if it has already
52  * been placed there. However, the EFI may not yet have been placed in the AIL
53  * when called by xfs_efi_release() from EFD processing due to the ordering of
54  * committed vs unpin operations in bulk insert operations. Hence the reference
55  * count to ensure only the last caller frees the EFI.
56  */
57 STATIC void
58 __xfs_efi_release(
59 	struct xfs_efi_log_item	*efip)
60 {
61 	struct xfs_ail		*ailp = efip->efi_item.li_ailp;
62 
63 	if (atomic_dec_and_test(&efip->efi_refcount)) {
64 		spin_lock(&ailp->xa_lock);
65 		/* xfs_trans_ail_delete() drops the AIL lock. */
66 		xfs_trans_ail_delete(ailp, &efip->efi_item,
67 				     SHUTDOWN_LOG_IO_ERROR);
68 		xfs_efi_item_free(efip);
69 	}
70 }
71 
72 /*
73  * This returns the number of iovecs needed to log the given efi item.
74  * We only need 1 iovec for an efi item.  It just logs the efi_log_format
75  * structure.
76  */
77 static inline int
78 xfs_efi_item_sizeof(
79 	struct xfs_efi_log_item *efip)
80 {
81 	return sizeof(struct xfs_efi_log_format) +
82 	       (efip->efi_format.efi_nextents - 1) * sizeof(xfs_extent_t);
83 }
84 
85 STATIC void
86 xfs_efi_item_size(
87 	struct xfs_log_item	*lip,
88 	int			*nvecs,
89 	int			*nbytes)
90 {
91 	*nvecs += 1;
92 	*nbytes += xfs_efi_item_sizeof(EFI_ITEM(lip));
93 }
94 
95 /*
96  * This is called to fill in the vector of log iovecs for the
97  * given efi log item. We use only 1 iovec, and we point that
98  * at the efi_log_format structure embedded in the efi item.
99  * It is at this point that we assert that all of the extent
100  * slots in the efi item have been filled.
101  */
102 STATIC void
103 xfs_efi_item_format(
104 	struct xfs_log_item	*lip,
105 	struct xfs_log_vec	*lv)
106 {
107 	struct xfs_efi_log_item	*efip = EFI_ITEM(lip);
108 	struct xfs_log_iovec	*vecp = NULL;
109 
110 	ASSERT(atomic_read(&efip->efi_next_extent) ==
111 				efip->efi_format.efi_nextents);
112 
113 	efip->efi_format.efi_type = XFS_LI_EFI;
114 	efip->efi_format.efi_size = 1;
115 
116 	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_EFI_FORMAT,
117 			&efip->efi_format,
118 			xfs_efi_item_sizeof(efip));
119 }
120 
121 
122 /*
123  * Pinning has no meaning for an efi item, so just return.
124  */
125 STATIC void
126 xfs_efi_item_pin(
127 	struct xfs_log_item	*lip)
128 {
129 }
130 
131 /*
132  * While EFIs cannot really be pinned, the unpin operation is the last place at
133  * which the EFI is manipulated during a transaction.  If we are being asked to
134  * remove the EFI it's because the transaction has been cancelled and by
135  * definition that means the EFI cannot be in the AIL so remove it from the
136  * transaction and free it.  Otherwise coordinate with xfs_efi_release()
137  * to determine who gets to free the EFI.
138  */
139 STATIC void
140 xfs_efi_item_unpin(
141 	struct xfs_log_item	*lip,
142 	int			remove)
143 {
144 	struct xfs_efi_log_item	*efip = EFI_ITEM(lip);
145 
146 	if (remove) {
147 		ASSERT(!(lip->li_flags & XFS_LI_IN_AIL));
148 		if (lip->li_desc)
149 			xfs_trans_del_item(lip);
150 		xfs_efi_item_free(efip);
151 		return;
152 	}
153 	__xfs_efi_release(efip);
154 }
155 
156 /*
157  * Efi items have no locking or pushing.  However, since EFIs are pulled from
158  * the AIL when their corresponding EFDs are committed to disk, their situation
159  * is very similar to being pinned.  Return XFS_ITEM_PINNED so that the caller
160  * will eventually flush the log.  This should help in getting the EFI out of
161  * the AIL.
162  */
163 STATIC uint
164 xfs_efi_item_push(
165 	struct xfs_log_item	*lip,
166 	struct list_head	*buffer_list)
167 {
168 	return XFS_ITEM_PINNED;
169 }
170 
171 STATIC void
172 xfs_efi_item_unlock(
173 	struct xfs_log_item	*lip)
174 {
175 	if (lip->li_flags & XFS_LI_ABORTED)
176 		xfs_efi_item_free(EFI_ITEM(lip));
177 }
178 
179 /*
180  * The EFI is logged only once and cannot be moved in the log, so simply return
181  * the lsn at which it's been logged.
182  */
183 STATIC xfs_lsn_t
184 xfs_efi_item_committed(
185 	struct xfs_log_item	*lip,
186 	xfs_lsn_t		lsn)
187 {
188 	return lsn;
189 }
190 
191 /*
192  * The EFI dependency tracking op doesn't do squat.  It can't because
193  * it doesn't know where the free extent is coming from.  The dependency
194  * tracking has to be handled by the "enclosing" metadata object.  For
195  * example, for inodes, the inode is locked throughout the extent freeing
196  * so the dependency should be recorded there.
197  */
198 STATIC void
199 xfs_efi_item_committing(
200 	struct xfs_log_item	*lip,
201 	xfs_lsn_t		lsn)
202 {
203 }
204 
205 /*
206  * This is the ops vector shared by all efi log items.
207  */
208 static const struct xfs_item_ops xfs_efi_item_ops = {
209 	.iop_size	= xfs_efi_item_size,
210 	.iop_format	= xfs_efi_item_format,
211 	.iop_pin	= xfs_efi_item_pin,
212 	.iop_unpin	= xfs_efi_item_unpin,
213 	.iop_unlock	= xfs_efi_item_unlock,
214 	.iop_committed	= xfs_efi_item_committed,
215 	.iop_push	= xfs_efi_item_push,
216 	.iop_committing = xfs_efi_item_committing
217 };
218 
219 
220 /*
221  * Allocate and initialize an efi item with the given number of extents.
222  */
223 struct xfs_efi_log_item *
224 xfs_efi_init(
225 	struct xfs_mount	*mp,
226 	uint			nextents)
227 
228 {
229 	struct xfs_efi_log_item	*efip;
230 	uint			size;
231 
232 	ASSERT(nextents > 0);
233 	if (nextents > XFS_EFI_MAX_FAST_EXTENTS) {
234 		size = (uint)(sizeof(xfs_efi_log_item_t) +
235 			((nextents - 1) * sizeof(xfs_extent_t)));
236 		efip = kmem_zalloc(size, KM_SLEEP);
237 	} else {
238 		efip = kmem_zone_zalloc(xfs_efi_zone, KM_SLEEP);
239 	}
240 
241 	xfs_log_item_init(mp, &efip->efi_item, XFS_LI_EFI, &xfs_efi_item_ops);
242 	efip->efi_format.efi_nextents = nextents;
243 	efip->efi_format.efi_id = (__psint_t)(void*)efip;
244 	atomic_set(&efip->efi_next_extent, 0);
245 	atomic_set(&efip->efi_refcount, 2);
246 
247 	return efip;
248 }
249 
250 /*
251  * Copy an EFI format buffer from the given buf, and into the destination
252  * EFI format structure.
253  * The given buffer can be in 32 bit or 64 bit form (which has different padding),
254  * one of which will be the native format for this kernel.
255  * It will handle the conversion of formats if necessary.
256  */
257 int
258 xfs_efi_copy_format(xfs_log_iovec_t *buf, xfs_efi_log_format_t *dst_efi_fmt)
259 {
260 	xfs_efi_log_format_t *src_efi_fmt = buf->i_addr;
261 	uint i;
262 	uint len = sizeof(xfs_efi_log_format_t) +
263 		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_t);
264 	uint len32 = sizeof(xfs_efi_log_format_32_t) +
265 		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_32_t);
266 	uint len64 = sizeof(xfs_efi_log_format_64_t) +
267 		(src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_64_t);
268 
269 	if (buf->i_len == len) {
270 		memcpy((char *)dst_efi_fmt, (char*)src_efi_fmt, len);
271 		return 0;
272 	} else if (buf->i_len == len32) {
273 		xfs_efi_log_format_32_t *src_efi_fmt_32 = buf->i_addr;
274 
275 		dst_efi_fmt->efi_type     = src_efi_fmt_32->efi_type;
276 		dst_efi_fmt->efi_size     = src_efi_fmt_32->efi_size;
277 		dst_efi_fmt->efi_nextents = src_efi_fmt_32->efi_nextents;
278 		dst_efi_fmt->efi_id       = src_efi_fmt_32->efi_id;
279 		for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
280 			dst_efi_fmt->efi_extents[i].ext_start =
281 				src_efi_fmt_32->efi_extents[i].ext_start;
282 			dst_efi_fmt->efi_extents[i].ext_len =
283 				src_efi_fmt_32->efi_extents[i].ext_len;
284 		}
285 		return 0;
286 	} else if (buf->i_len == len64) {
287 		xfs_efi_log_format_64_t *src_efi_fmt_64 = buf->i_addr;
288 
289 		dst_efi_fmt->efi_type     = src_efi_fmt_64->efi_type;
290 		dst_efi_fmt->efi_size     = src_efi_fmt_64->efi_size;
291 		dst_efi_fmt->efi_nextents = src_efi_fmt_64->efi_nextents;
292 		dst_efi_fmt->efi_id       = src_efi_fmt_64->efi_id;
293 		for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
294 			dst_efi_fmt->efi_extents[i].ext_start =
295 				src_efi_fmt_64->efi_extents[i].ext_start;
296 			dst_efi_fmt->efi_extents[i].ext_len =
297 				src_efi_fmt_64->efi_extents[i].ext_len;
298 		}
299 		return 0;
300 	}
301 	return -EFSCORRUPTED;
302 }
303 
304 /*
305  * This is called by the efd item code below to release references to the given
306  * efi item.  Each efd calls this with the number of extents that it has
307  * logged, and when the sum of these reaches the total number of extents logged
308  * by this efi item we can free the efi item.
309  */
310 void
311 xfs_efi_release(xfs_efi_log_item_t	*efip,
312 		uint			nextents)
313 {
314 	ASSERT(atomic_read(&efip->efi_next_extent) >= nextents);
315 	if (atomic_sub_and_test(nextents, &efip->efi_next_extent)) {
316 		/* recovery needs us to drop the EFI reference, too */
317 		if (test_bit(XFS_EFI_RECOVERED, &efip->efi_flags))
318 			__xfs_efi_release(efip);
319 
320 		__xfs_efi_release(efip);
321 		/* efip may now have been freed, do not reference it again. */
322 	}
323 }
324 
325 static inline struct xfs_efd_log_item *EFD_ITEM(struct xfs_log_item *lip)
326 {
327 	return container_of(lip, struct xfs_efd_log_item, efd_item);
328 }
329 
330 STATIC void
331 xfs_efd_item_free(struct xfs_efd_log_item *efdp)
332 {
333 	if (efdp->efd_format.efd_nextents > XFS_EFD_MAX_FAST_EXTENTS)
334 		kmem_free(efdp);
335 	else
336 		kmem_zone_free(xfs_efd_zone, efdp);
337 }
338 
339 /*
340  * This returns the number of iovecs needed to log the given efd item.
341  * We only need 1 iovec for an efd item.  It just logs the efd_log_format
342  * structure.
343  */
344 static inline int
345 xfs_efd_item_sizeof(
346 	struct xfs_efd_log_item *efdp)
347 {
348 	return sizeof(xfs_efd_log_format_t) +
349 	       (efdp->efd_format.efd_nextents - 1) * sizeof(xfs_extent_t);
350 }
351 
352 STATIC void
353 xfs_efd_item_size(
354 	struct xfs_log_item	*lip,
355 	int			*nvecs,
356 	int			*nbytes)
357 {
358 	*nvecs += 1;
359 	*nbytes += xfs_efd_item_sizeof(EFD_ITEM(lip));
360 }
361 
362 /*
363  * This is called to fill in the vector of log iovecs for the
364  * given efd log item. We use only 1 iovec, and we point that
365  * at the efd_log_format structure embedded in the efd item.
366  * It is at this point that we assert that all of the extent
367  * slots in the efd item have been filled.
368  */
369 STATIC void
370 xfs_efd_item_format(
371 	struct xfs_log_item	*lip,
372 	struct xfs_log_vec	*lv)
373 {
374 	struct xfs_efd_log_item	*efdp = EFD_ITEM(lip);
375 	struct xfs_log_iovec	*vecp = NULL;
376 
377 	ASSERT(efdp->efd_next_extent == efdp->efd_format.efd_nextents);
378 
379 	efdp->efd_format.efd_type = XFS_LI_EFD;
380 	efdp->efd_format.efd_size = 1;
381 
382 	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_EFD_FORMAT,
383 			&efdp->efd_format,
384 			xfs_efd_item_sizeof(efdp));
385 }
386 
387 /*
388  * Pinning has no meaning for an efd item, so just return.
389  */
390 STATIC void
391 xfs_efd_item_pin(
392 	struct xfs_log_item	*lip)
393 {
394 }
395 
396 /*
397  * Since pinning has no meaning for an efd item, unpinning does
398  * not either.
399  */
400 STATIC void
401 xfs_efd_item_unpin(
402 	struct xfs_log_item	*lip,
403 	int			remove)
404 {
405 }
406 
407 /*
408  * There isn't much you can do to push on an efd item.  It is simply stuck
409  * waiting for the log to be flushed to disk.
410  */
411 STATIC uint
412 xfs_efd_item_push(
413 	struct xfs_log_item	*lip,
414 	struct list_head	*buffer_list)
415 {
416 	return XFS_ITEM_PINNED;
417 }
418 
419 STATIC void
420 xfs_efd_item_unlock(
421 	struct xfs_log_item	*lip)
422 {
423 	if (lip->li_flags & XFS_LI_ABORTED)
424 		xfs_efd_item_free(EFD_ITEM(lip));
425 }
426 
427 /*
428  * When the efd item is committed to disk, all we need to do
429  * is delete our reference to our partner efi item and then
430  * free ourselves.  Since we're freeing ourselves we must
431  * return -1 to keep the transaction code from further referencing
432  * this item.
433  */
434 STATIC xfs_lsn_t
435 xfs_efd_item_committed(
436 	struct xfs_log_item	*lip,
437 	xfs_lsn_t		lsn)
438 {
439 	struct xfs_efd_log_item	*efdp = EFD_ITEM(lip);
440 
441 	/*
442 	 * If we got a log I/O error, it's always the case that the LR with the
443 	 * EFI got unpinned and freed before the EFD got aborted.
444 	 */
445 	if (!(lip->li_flags & XFS_LI_ABORTED))
446 		xfs_efi_release(efdp->efd_efip, efdp->efd_format.efd_nextents);
447 
448 	xfs_efd_item_free(efdp);
449 	return (xfs_lsn_t)-1;
450 }
451 
452 /*
453  * The EFD dependency tracking op doesn't do squat.  It can't because
454  * it doesn't know where the free extent is coming from.  The dependency
455  * tracking has to be handled by the "enclosing" metadata object.  For
456  * example, for inodes, the inode is locked throughout the extent freeing
457  * so the dependency should be recorded there.
458  */
459 STATIC void
460 xfs_efd_item_committing(
461 	struct xfs_log_item	*lip,
462 	xfs_lsn_t		lsn)
463 {
464 }
465 
466 /*
467  * This is the ops vector shared by all efd log items.
468  */
469 static const struct xfs_item_ops xfs_efd_item_ops = {
470 	.iop_size	= xfs_efd_item_size,
471 	.iop_format	= xfs_efd_item_format,
472 	.iop_pin	= xfs_efd_item_pin,
473 	.iop_unpin	= xfs_efd_item_unpin,
474 	.iop_unlock	= xfs_efd_item_unlock,
475 	.iop_committed	= xfs_efd_item_committed,
476 	.iop_push	= xfs_efd_item_push,
477 	.iop_committing = xfs_efd_item_committing
478 };
479 
480 /*
481  * Allocate and initialize an efd item with the given number of extents.
482  */
483 struct xfs_efd_log_item *
484 xfs_efd_init(
485 	struct xfs_mount	*mp,
486 	struct xfs_efi_log_item	*efip,
487 	uint			nextents)
488 
489 {
490 	struct xfs_efd_log_item	*efdp;
491 	uint			size;
492 
493 	ASSERT(nextents > 0);
494 	if (nextents > XFS_EFD_MAX_FAST_EXTENTS) {
495 		size = (uint)(sizeof(xfs_efd_log_item_t) +
496 			((nextents - 1) * sizeof(xfs_extent_t)));
497 		efdp = kmem_zalloc(size, KM_SLEEP);
498 	} else {
499 		efdp = kmem_zone_zalloc(xfs_efd_zone, KM_SLEEP);
500 	}
501 
502 	xfs_log_item_init(mp, &efdp->efd_item, XFS_LI_EFD, &xfs_efd_item_ops);
503 	efdp->efd_efip = efip;
504 	efdp->efd_format.efd_nextents = nextents;
505 	efdp->efd_format.efd_efi_id = efip->efi_format.efi_id;
506 
507 	return efdp;
508 }
509