xref: /linux/fs/ocfs2/slot_map.c (revision f3449bf31d352f70c80a7993c272a7854ae98086) 
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * slot_map.c
5  *
6  *
7  *
8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  */
25 
26 #include <linux/types.h>
27 #include <linux/slab.h>
28 #include <linux/highmem.h>
29 
30 #define MLOG_MASK_PREFIX ML_SUPER
31 #include <cluster/masklog.h>
32 
33 #include "ocfs2.h"
34 
35 #include "dlmglue.h"
36 #include "extent_map.h"
37 #include "heartbeat.h"
38 #include "inode.h"
39 #include "slot_map.h"
40 #include "super.h"
41 #include "sysfile.h"
42 
43 #include "buffer_head_io.h"
44 
45 
46 struct ocfs2_slot {
47 	int sl_valid;
48 	unsigned int sl_node_num;
49 };
50 
51 struct ocfs2_slot_info {
52 	int si_extended;
53 	int si_slots_per_block;
54 	struct inode *si_inode;
55 	unsigned int si_blocks;
56 	struct buffer_head **si_bh;
57 	unsigned int si_num_slots;
58 	struct ocfs2_slot *si_slots;
59 };
60 
61 
62 static int __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
63 				    unsigned int node_num);
64 
65 static void ocfs2_invalidate_slot(struct ocfs2_slot_info *si,
66 				  int slot_num)
67 {
68 	BUG_ON((slot_num < 0) || (slot_num >= si->si_num_slots));
69 	si->si_slots[slot_num].sl_valid = 0;
70 }
71 
72 static void ocfs2_set_slot(struct ocfs2_slot_info *si,
73 			   int slot_num, unsigned int node_num)
74 {
75 	BUG_ON((slot_num < 0) || (slot_num >= si->si_num_slots));
76 
77 	si->si_slots[slot_num].sl_valid = 1;
78 	si->si_slots[slot_num].sl_node_num = node_num;
79 }
80 
81 /* This version is for the extended slot map */
82 static void ocfs2_update_slot_info_extended(struct ocfs2_slot_info *si)
83 {
84 	int b, i, slotno;
85 	struct ocfs2_slot_map_extended *se;
86 
87 	slotno = 0;
88 	for (b = 0; b < si->si_blocks; b++) {
89 		se = (struct ocfs2_slot_map_extended *)si->si_bh[b]->b_data;
90 		for (i = 0;
91 		     (i < si->si_slots_per_block) &&
92 		     (slotno < si->si_num_slots);
93 		     i++, slotno++) {
94 			if (se->se_slots[i].es_valid)
95 				ocfs2_set_slot(si, slotno,
96 					       le32_to_cpu(se->se_slots[i].es_node_num));
97 			else
98 				ocfs2_invalidate_slot(si, slotno);
99 		}
100 	}
101 }
102 
103 /*
104  * Post the slot information on disk into our slot_info struct.
105  * Must be protected by osb_lock.
106  */
107 static void ocfs2_update_slot_info_old(struct ocfs2_slot_info *si)
108 {
109 	int i;
110 	struct ocfs2_slot_map *sm;
111 
112 	sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
113 
114 	for (i = 0; i < si->si_num_slots; i++) {
115 		if (le16_to_cpu(sm->sm_slots[i]) == (u16)OCFS2_INVALID_SLOT)
116 			ocfs2_invalidate_slot(si, i);
117 		else
118 			ocfs2_set_slot(si, i, le16_to_cpu(sm->sm_slots[i]));
119 	}
120 }
121 
122 static void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
123 {
124 	/*
125 	 * The slot data will have been refreshed when ocfs2_super_lock
126 	 * was taken.
127 	 */
128 	if (si->si_extended)
129 		ocfs2_update_slot_info_extended(si);
130 	else
131 		ocfs2_update_slot_info_old(si);
132 }
133 
134 int ocfs2_refresh_slot_info(struct ocfs2_super *osb)
135 {
136 	int ret;
137 	struct ocfs2_slot_info *si = osb->slot_info;
138 
139 	if (si == NULL)
140 		return 0;
141 
142 	BUG_ON(si->si_blocks == 0);
143 	BUG_ON(si->si_bh == NULL);
144 
145 	mlog(0, "Refreshing slot map, reading %u block(s)\n",
146 	     si->si_blocks);
147 
148 	/*
149 	 * We pass -1 as blocknr because we expect all of si->si_bh to
150 	 * be !NULL.  Thus, ocfs2_read_blocks() will ignore blocknr.  If
151 	 * this is not true, the read of -1 (UINT64_MAX) will fail.
152 	 */
153 	ret = ocfs2_read_blocks(INODE_CACHE(si->si_inode), -1, si->si_blocks,
154 				si->si_bh, OCFS2_BH_IGNORE_CACHE, NULL);
155 	if (ret == 0) {
156 		spin_lock(&osb->osb_lock);
157 		ocfs2_update_slot_info(si);
158 		spin_unlock(&osb->osb_lock);
159 	}
160 
161 	return ret;
162 }
163 
164 /* post the our slot info stuff into it's destination bh and write it
165  * out. */
166 static void ocfs2_update_disk_slot_extended(struct ocfs2_slot_info *si,
167 					    int slot_num,
168 					    struct buffer_head **bh)
169 {
170 	int blkind = slot_num / si->si_slots_per_block;
171 	int slotno = slot_num % si->si_slots_per_block;
172 	struct ocfs2_slot_map_extended *se;
173 
174 	BUG_ON(blkind >= si->si_blocks);
175 
176 	se = (struct ocfs2_slot_map_extended *)si->si_bh[blkind]->b_data;
177 	se->se_slots[slotno].es_valid = si->si_slots[slot_num].sl_valid;
178 	if (si->si_slots[slot_num].sl_valid)
179 		se->se_slots[slotno].es_node_num =
180 			cpu_to_le32(si->si_slots[slot_num].sl_node_num);
181 	*bh = si->si_bh[blkind];
182 }
183 
184 static void ocfs2_update_disk_slot_old(struct ocfs2_slot_info *si,
185 				       int slot_num,
186 				       struct buffer_head **bh)
187 {
188 	int i;
189 	struct ocfs2_slot_map *sm;
190 
191 	sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
192 	for (i = 0; i < si->si_num_slots; i++) {
193 		if (si->si_slots[i].sl_valid)
194 			sm->sm_slots[i] =
195 				cpu_to_le16(si->si_slots[i].sl_node_num);
196 		else
197 			sm->sm_slots[i] = cpu_to_le16(OCFS2_INVALID_SLOT);
198 	}
199 	*bh = si->si_bh[0];
200 }
201 
202 static int ocfs2_update_disk_slot(struct ocfs2_super *osb,
203 				  struct ocfs2_slot_info *si,
204 				  int slot_num)
205 {
206 	int status;
207 	struct buffer_head *bh;
208 
209 	spin_lock(&osb->osb_lock);
210 	if (si->si_extended)
211 		ocfs2_update_disk_slot_extended(si, slot_num, &bh);
212 	else
213 		ocfs2_update_disk_slot_old(si, slot_num, &bh);
214 	spin_unlock(&osb->osb_lock);
215 
216 	status = ocfs2_write_block(osb, bh, INODE_CACHE(si->si_inode));
217 	if (status < 0)
218 		mlog_errno(status);
219 
220 	return status;
221 }
222 
223 /*
224  * Calculate how many bytes are needed by the slot map.  Returns
225  * an error if the slot map file is too small.
226  */
227 static int ocfs2_slot_map_physical_size(struct ocfs2_super *osb,
228 					struct inode *inode,
229 					unsigned long long *bytes)
230 {
231 	unsigned long long bytes_needed;
232 
233 	if (ocfs2_uses_extended_slot_map(osb)) {
234 		bytes_needed = osb->max_slots *
235 			sizeof(struct ocfs2_extended_slot);
236 	} else {
237 		bytes_needed = osb->max_slots * sizeof(__le16);
238 	}
239 	if (bytes_needed > i_size_read(inode)) {
240 		mlog(ML_ERROR,
241 		     "Slot map file is too small!  (size %llu, needed %llu)\n",
242 		     i_size_read(inode), bytes_needed);
243 		return -ENOSPC;
244 	}
245 
246 	*bytes = bytes_needed;
247 	return 0;
248 }
249 
250 /* try to find global node in the slot info. Returns -ENOENT
251  * if nothing is found. */
252 static int __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
253 				    unsigned int node_num)
254 {
255 	int i, ret = -ENOENT;
256 
257 	for(i = 0; i < si->si_num_slots; i++) {
258 		if (si->si_slots[i].sl_valid &&
259 		    (node_num == si->si_slots[i].sl_node_num)) {
260 			ret = i;
261 			break;
262 		}
263 	}
264 
265 	return ret;
266 }
267 
268 static int __ocfs2_find_empty_slot(struct ocfs2_slot_info *si,
269 				   int preferred)
270 {
271 	int i, ret = -ENOSPC;
272 
273 	if ((preferred >= 0) && (preferred < si->si_num_slots)) {
274 		if (!si->si_slots[preferred].sl_valid) {
275 			ret = preferred;
276 			goto out;
277 		}
278 	}
279 
280 	for(i = 0; i < si->si_num_slots; i++) {
281 		if (!si->si_slots[i].sl_valid) {
282 			ret = i;
283 			break;
284 		}
285 	}
286 out:
287 	return ret;
288 }
289 
290 int ocfs2_node_num_to_slot(struct ocfs2_super *osb, unsigned int node_num)
291 {
292 	int slot;
293 	struct ocfs2_slot_info *si = osb->slot_info;
294 
295 	spin_lock(&osb->osb_lock);
296 	slot = __ocfs2_node_num_to_slot(si, node_num);
297 	spin_unlock(&osb->osb_lock);
298 
299 	return slot;
300 }
301 
302 int ocfs2_slot_to_node_num_locked(struct ocfs2_super *osb, int slot_num,
303 				  unsigned int *node_num)
304 {
305 	struct ocfs2_slot_info *si = osb->slot_info;
306 
307 	assert_spin_locked(&osb->osb_lock);
308 
309 	BUG_ON(slot_num < 0);
310 	BUG_ON(slot_num > osb->max_slots);
311 
312 	if (!si->si_slots[slot_num].sl_valid)
313 		return -ENOENT;
314 
315 	*node_num = si->si_slots[slot_num].sl_node_num;
316 	return 0;
317 }
318 
319 static void __ocfs2_free_slot_info(struct ocfs2_slot_info *si)
320 {
321 	unsigned int i;
322 
323 	if (si == NULL)
324 		return;
325 
326 	if (si->si_inode)
327 		iput(si->si_inode);
328 	if (si->si_bh) {
329 		for (i = 0; i < si->si_blocks; i++) {
330 			if (si->si_bh[i]) {
331 				brelse(si->si_bh[i]);
332 				si->si_bh[i] = NULL;
333 			}
334 		}
335 		kfree(si->si_bh);
336 	}
337 
338 	kfree(si);
339 }
340 
341 int ocfs2_clear_slot(struct ocfs2_super *osb, int slot_num)
342 {
343 	struct ocfs2_slot_info *si = osb->slot_info;
344 
345 	if (si == NULL)
346 		return 0;
347 
348 	spin_lock(&osb->osb_lock);
349 	ocfs2_invalidate_slot(si, slot_num);
350 	spin_unlock(&osb->osb_lock);
351 
352 	return ocfs2_update_disk_slot(osb, osb->slot_info, slot_num);
353 }
354 
355 static int ocfs2_map_slot_buffers(struct ocfs2_super *osb,
356 				  struct ocfs2_slot_info *si)
357 {
358 	int status = 0;
359 	u64 blkno;
360 	unsigned long long blocks, bytes = 0;
361 	unsigned int i;
362 	struct buffer_head *bh;
363 
364 	status = ocfs2_slot_map_physical_size(osb, si->si_inode, &bytes);
365 	if (status)
366 		goto bail;
367 
368 	blocks = ocfs2_blocks_for_bytes(si->si_inode->i_sb, bytes);
369 	BUG_ON(blocks > UINT_MAX);
370 	si->si_blocks = blocks;
371 	if (!si->si_blocks)
372 		goto bail;
373 
374 	if (si->si_extended)
375 		si->si_slots_per_block =
376 			(osb->sb->s_blocksize /
377 			 sizeof(struct ocfs2_extended_slot));
378 	else
379 		si->si_slots_per_block = osb->sb->s_blocksize / sizeof(__le16);
380 
381 	/* The size checks above should ensure this */
382 	BUG_ON((osb->max_slots / si->si_slots_per_block) > blocks);
383 
384 	mlog(0, "Slot map needs %u buffers for %llu bytes\n",
385 	     si->si_blocks, bytes);
386 
387 	si->si_bh = kzalloc(sizeof(struct buffer_head *) * si->si_blocks,
388 			    GFP_KERNEL);
389 	if (!si->si_bh) {
390 		status = -ENOMEM;
391 		mlog_errno(status);
392 		goto bail;
393 	}
394 
395 	for (i = 0; i < si->si_blocks; i++) {
396 		status = ocfs2_extent_map_get_blocks(si->si_inode, i,
397 						     &blkno, NULL, NULL);
398 		if (status < 0) {
399 			mlog_errno(status);
400 			goto bail;
401 		}
402 
403 		mlog(0, "Reading slot map block %u at %llu\n", i,
404 		     (unsigned long long)blkno);
405 
406 		bh = NULL;  /* Acquire a fresh bh */
407 		status = ocfs2_read_blocks(INODE_CACHE(si->si_inode), blkno,
408 					   1, &bh, OCFS2_BH_IGNORE_CACHE, NULL);
409 		if (status < 0) {
410 			mlog_errno(status);
411 			goto bail;
412 		}
413 
414 		si->si_bh[i] = bh;
415 	}
416 
417 bail:
418 	return status;
419 }
420 
421 int ocfs2_init_slot_info(struct ocfs2_super *osb)
422 {
423 	int status;
424 	struct inode *inode = NULL;
425 	struct ocfs2_slot_info *si;
426 
427 	si = kzalloc(sizeof(struct ocfs2_slot_info) +
428 		     (sizeof(struct ocfs2_slot) * osb->max_slots),
429 		     GFP_KERNEL);
430 	if (!si) {
431 		status = -ENOMEM;
432 		mlog_errno(status);
433 		goto bail;
434 	}
435 
436 	si->si_extended = ocfs2_uses_extended_slot_map(osb);
437 	si->si_num_slots = osb->max_slots;
438 	si->si_slots = (struct ocfs2_slot *)((char *)si +
439 					     sizeof(struct ocfs2_slot_info));
440 
441 	inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
442 					    OCFS2_INVALID_SLOT);
443 	if (!inode) {
444 		status = -EINVAL;
445 		mlog_errno(status);
446 		goto bail;
447 	}
448 
449 	si->si_inode = inode;
450 	status = ocfs2_map_slot_buffers(osb, si);
451 	if (status < 0) {
452 		mlog_errno(status);
453 		goto bail;
454 	}
455 
456 	osb->slot_info = (struct ocfs2_slot_info *)si;
457 bail:
458 	if (status < 0 && si)
459 		__ocfs2_free_slot_info(si);
460 
461 	return status;
462 }
463 
464 void ocfs2_free_slot_info(struct ocfs2_super *osb)
465 {
466 	struct ocfs2_slot_info *si = osb->slot_info;
467 
468 	osb->slot_info = NULL;
469 	__ocfs2_free_slot_info(si);
470 }
471 
472 int ocfs2_find_slot(struct ocfs2_super *osb)
473 {
474 	int status;
475 	int slot;
476 	struct ocfs2_slot_info *si;
477 
478 	mlog_entry_void();
479 
480 	si = osb->slot_info;
481 
482 	spin_lock(&osb->osb_lock);
483 	ocfs2_update_slot_info(si);
484 
485 	/* search for ourselves first and take the slot if it already
486 	 * exists. Perhaps we need to mark this in a variable for our
487 	 * own journal recovery? Possibly not, though we certainly
488 	 * need to warn to the user */
489 	slot = __ocfs2_node_num_to_slot(si, osb->node_num);
490 	if (slot < 0) {
491 		/* if no slot yet, then just take 1st available
492 		 * one. */
493 		slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
494 		if (slot < 0) {
495 			spin_unlock(&osb->osb_lock);
496 			mlog(ML_ERROR, "no free slots available!\n");
497 			status = -EINVAL;
498 			goto bail;
499 		}
500 	} else
501 		mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
502 		     slot);
503 
504 	ocfs2_set_slot(si, slot, osb->node_num);
505 	osb->slot_num = slot;
506 	spin_unlock(&osb->osb_lock);
507 
508 	mlog(0, "taking node slot %d\n", osb->slot_num);
509 
510 	status = ocfs2_update_disk_slot(osb, si, osb->slot_num);
511 	if (status < 0)
512 		mlog_errno(status);
513 
514 bail:
515 	mlog_exit(status);
516 	return status;
517 }
518 
519 void ocfs2_put_slot(struct ocfs2_super *osb)
520 {
521 	int status, slot_num;
522 	struct ocfs2_slot_info *si = osb->slot_info;
523 
524 	if (!si)
525 		return;
526 
527 	spin_lock(&osb->osb_lock);
528 	ocfs2_update_slot_info(si);
529 
530 	slot_num = osb->slot_num;
531 	ocfs2_invalidate_slot(si, osb->slot_num);
532 	osb->slot_num = OCFS2_INVALID_SLOT;
533 	spin_unlock(&osb->osb_lock);
534 
535 	status = ocfs2_update_disk_slot(osb, si, slot_num);
536 	if (status < 0) {
537 		mlog_errno(status);
538 		goto bail;
539 	}
540 
541 bail:
542 	ocfs2_free_slot_info(osb);
543 }
544 
545