xref: /openbmc/linux/fs/ocfs2/slot_map.c (revision f9a82c48) 
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 #include <cluster/masklog.h>
31 
32 #include "ocfs2.h"
33 
34 #include "dlmglue.h"
35 #include "extent_map.h"
36 #include "heartbeat.h"
37 #include "inode.h"
38 #include "slot_map.h"
39 #include "super.h"
40 #include "sysfile.h"
41 #include "ocfs2_trace.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 	trace_ocfs2_refresh_slot_info(si->si_blocks);
146 
147 	/*
148 	 * We pass -1 as blocknr because we expect all of si->si_bh to
149 	 * be !NULL.  Thus, ocfs2_read_blocks() will ignore blocknr.  If
150 	 * this is not true, the read of -1 (UINT64_MAX) will fail.
151 	 */
152 	ret = ocfs2_read_blocks(INODE_CACHE(si->si_inode), -1, si->si_blocks,
153 				si->si_bh, OCFS2_BH_IGNORE_CACHE, NULL);
154 	if (ret == 0) {
155 		spin_lock(&osb->osb_lock);
156 		ocfs2_update_slot_info(si);
157 		spin_unlock(&osb->osb_lock);
158 	}
159 
160 	return ret;
161 }
162 
163 /* post the our slot info stuff into it's destination bh and write it
164  * out. */
165 static void ocfs2_update_disk_slot_extended(struct ocfs2_slot_info *si,
166 					    int slot_num,
167 					    struct buffer_head **bh)
168 {
169 	int blkind = slot_num / si->si_slots_per_block;
170 	int slotno = slot_num % si->si_slots_per_block;
171 	struct ocfs2_slot_map_extended *se;
172 
173 	BUG_ON(blkind >= si->si_blocks);
174 
175 	se = (struct ocfs2_slot_map_extended *)si->si_bh[blkind]->b_data;
176 	se->se_slots[slotno].es_valid = si->si_slots[slot_num].sl_valid;
177 	if (si->si_slots[slot_num].sl_valid)
178 		se->se_slots[slotno].es_node_num =
179 			cpu_to_le32(si->si_slots[slot_num].sl_node_num);
180 	*bh = si->si_bh[blkind];
181 }
182 
183 static void ocfs2_update_disk_slot_old(struct ocfs2_slot_info *si,
184 				       int slot_num,
185 				       struct buffer_head **bh)
186 {
187 	int i;
188 	struct ocfs2_slot_map *sm;
189 
190 	sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
191 	for (i = 0; i < si->si_num_slots; i++) {
192 		if (si->si_slots[i].sl_valid)
193 			sm->sm_slots[i] =
194 				cpu_to_le16(si->si_slots[i].sl_node_num);
195 		else
196 			sm->sm_slots[i] = cpu_to_le16(OCFS2_INVALID_SLOT);
197 	}
198 	*bh = si->si_bh[0];
199 }
200 
201 static int ocfs2_update_disk_slot(struct ocfs2_super *osb,
202 				  struct ocfs2_slot_info *si,
203 				  int slot_num)
204 {
205 	int status;
206 	struct buffer_head *bh;
207 
208 	spin_lock(&osb->osb_lock);
209 	if (si->si_extended)
210 		ocfs2_update_disk_slot_extended(si, slot_num, &bh);
211 	else
212 		ocfs2_update_disk_slot_old(si, slot_num, &bh);
213 	spin_unlock(&osb->osb_lock);
214 
215 	status = ocfs2_write_block(osb, bh, INODE_CACHE(si->si_inode));
216 	if (status < 0)
217 		mlog_errno(status);
218 
219 	return status;
220 }
221 
222 /*
223  * Calculate how many bytes are needed by the slot map.  Returns
224  * an error if the slot map file is too small.
225  */
226 static int ocfs2_slot_map_physical_size(struct ocfs2_super *osb,
227 					struct inode *inode,
228 					unsigned long long *bytes)
229 {
230 	unsigned long long bytes_needed;
231 
232 	if (ocfs2_uses_extended_slot_map(osb)) {
233 		bytes_needed = osb->max_slots *
234 			sizeof(struct ocfs2_extended_slot);
235 	} else {
236 		bytes_needed = osb->max_slots * sizeof(__le16);
237 	}
238 	if (bytes_needed > i_size_read(inode)) {
239 		mlog(ML_ERROR,
240 		     "Slot map file is too small!  (size %llu, needed %llu)\n",
241 		     i_size_read(inode), bytes_needed);
242 		return -ENOSPC;
243 	}
244 
245 	*bytes = bytes_needed;
246 	return 0;
247 }
248 
249 /* try to find global node in the slot info. Returns -ENOENT
250  * if nothing is found. */
251 static int __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
252 				    unsigned int node_num)
253 {
254 	int i, ret = -ENOENT;
255 
256 	for(i = 0; i < si->si_num_slots; i++) {
257 		if (si->si_slots[i].sl_valid &&
258 		    (node_num == si->si_slots[i].sl_node_num)) {
259 			ret = i;
260 			break;
261 		}
262 	}
263 
264 	return ret;
265 }
266 
267 static int __ocfs2_find_empty_slot(struct ocfs2_slot_info *si,
268 				   int preferred)
269 {
270 	int i, ret = -ENOSPC;
271 
272 	if ((preferred >= 0) && (preferred < si->si_num_slots)) {
273 		if (!si->si_slots[preferred].sl_valid) {
274 			ret = preferred;
275 			goto out;
276 		}
277 	}
278 
279 	for(i = 0; i < si->si_num_slots; i++) {
280 		if (!si->si_slots[i].sl_valid) {
281 			ret = i;
282 			break;
283 		}
284 	}
285 out:
286 	return ret;
287 }
288 
289 int ocfs2_node_num_to_slot(struct ocfs2_super *osb, unsigned int node_num)
290 {
291 	int slot;
292 	struct ocfs2_slot_info *si = osb->slot_info;
293 
294 	spin_lock(&osb->osb_lock);
295 	slot = __ocfs2_node_num_to_slot(si, node_num);
296 	spin_unlock(&osb->osb_lock);
297 
298 	return slot;
299 }
300 
301 int ocfs2_slot_to_node_num_locked(struct ocfs2_super *osb, int slot_num,
302 				  unsigned int *node_num)
303 {
304 	struct ocfs2_slot_info *si = osb->slot_info;
305 
306 	assert_spin_locked(&osb->osb_lock);
307 
308 	BUG_ON(slot_num < 0);
309 	BUG_ON(slot_num >= osb->max_slots);
310 
311 	if (!si->si_slots[slot_num].sl_valid)
312 		return -ENOENT;
313 
314 	*node_num = si->si_slots[slot_num].sl_node_num;
315 	return 0;
316 }
317 
318 static void __ocfs2_free_slot_info(struct ocfs2_slot_info *si)
319 {
320 	unsigned int i;
321 
322 	if (si == NULL)
323 		return;
324 
325 	iput(si->si_inode);
326 	if (si->si_bh) {
327 		for (i = 0; i < si->si_blocks; i++) {
328 			if (si->si_bh[i]) {
329 				brelse(si->si_bh[i]);
330 				si->si_bh[i] = NULL;
331 			}
332 		}
333 		kfree(si->si_bh);
334 	}
335 
336 	kfree(si);
337 }
338 
339 int ocfs2_clear_slot(struct ocfs2_super *osb, int slot_num)
340 {
341 	struct ocfs2_slot_info *si = osb->slot_info;
342 
343 	if (si == NULL)
344 		return 0;
345 
346 	spin_lock(&osb->osb_lock);
347 	ocfs2_invalidate_slot(si, slot_num);
348 	spin_unlock(&osb->osb_lock);
349 
350 	return ocfs2_update_disk_slot(osb, osb->slot_info, slot_num);
351 }
352 
353 static int ocfs2_map_slot_buffers(struct ocfs2_super *osb,
354 				  struct ocfs2_slot_info *si)
355 {
356 	int status = 0;
357 	u64 blkno;
358 	unsigned long long blocks, bytes = 0;
359 	unsigned int i;
360 	struct buffer_head *bh;
361 
362 	status = ocfs2_slot_map_physical_size(osb, si->si_inode, &bytes);
363 	if (status)
364 		goto bail;
365 
366 	blocks = ocfs2_blocks_for_bytes(si->si_inode->i_sb, bytes);
367 	BUG_ON(blocks > UINT_MAX);
368 	si->si_blocks = blocks;
369 	if (!si->si_blocks)
370 		goto bail;
371 
372 	if (si->si_extended)
373 		si->si_slots_per_block =
374 			(osb->sb->s_blocksize /
375 			 sizeof(struct ocfs2_extended_slot));
376 	else
377 		si->si_slots_per_block = osb->sb->s_blocksize / sizeof(__le16);
378 
379 	/* The size checks above should ensure this */
380 	BUG_ON((osb->max_slots / si->si_slots_per_block) > blocks);
381 
382 	trace_ocfs2_map_slot_buffers(bytes, si->si_blocks);
383 
384 	si->si_bh = kcalloc(si->si_blocks, sizeof(struct buffer_head *),
385 			    GFP_KERNEL);
386 	if (!si->si_bh) {
387 		status = -ENOMEM;
388 		mlog_errno(status);
389 		goto bail;
390 	}
391 
392 	for (i = 0; i < si->si_blocks; i++) {
393 		status = ocfs2_extent_map_get_blocks(si->si_inode, i,
394 						     &blkno, NULL, NULL);
395 		if (status < 0) {
396 			mlog_errno(status);
397 			goto bail;
398 		}
399 
400 		trace_ocfs2_map_slot_buffers_block((unsigned long long)blkno, i);
401 
402 		bh = NULL;  /* Acquire a fresh bh */
403 		status = ocfs2_read_blocks(INODE_CACHE(si->si_inode), blkno,
404 					   1, &bh, OCFS2_BH_IGNORE_CACHE, NULL);
405 		if (status < 0) {
406 			mlog_errno(status);
407 			goto bail;
408 		}
409 
410 		si->si_bh[i] = bh;
411 	}
412 
413 bail:
414 	return status;
415 }
416 
417 int ocfs2_init_slot_info(struct ocfs2_super *osb)
418 {
419 	int status;
420 	struct inode *inode = NULL;
421 	struct ocfs2_slot_info *si;
422 
423 	si = kzalloc(struct_size(si, si_slots, osb->max_slots), GFP_KERNEL);
424 	if (!si) {
425 		status = -ENOMEM;
426 		mlog_errno(status);
427 		return status;
428 	}
429 
430 	si->si_extended = ocfs2_uses_extended_slot_map(osb);
431 	si->si_num_slots = osb->max_slots;
432 
433 	inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
434 					    OCFS2_INVALID_SLOT);
435 	if (!inode) {
436 		status = -EINVAL;
437 		mlog_errno(status);
438 		goto bail;
439 	}
440 
441 	si->si_inode = inode;
442 	status = ocfs2_map_slot_buffers(osb, si);
443 	if (status < 0) {
444 		mlog_errno(status);
445 		goto bail;
446 	}
447 
448 	osb->slot_info = (struct ocfs2_slot_info *)si;
449 bail:
450 	if (status < 0)
451 		__ocfs2_free_slot_info(si);
452 
453 	return status;
454 }
455 
456 void ocfs2_free_slot_info(struct ocfs2_super *osb)
457 {
458 	struct ocfs2_slot_info *si = osb->slot_info;
459 
460 	osb->slot_info = NULL;
461 	__ocfs2_free_slot_info(si);
462 }
463 
464 int ocfs2_find_slot(struct ocfs2_super *osb)
465 {
466 	int status;
467 	int slot;
468 	struct ocfs2_slot_info *si;
469 
470 	si = osb->slot_info;
471 
472 	spin_lock(&osb->osb_lock);
473 	ocfs2_update_slot_info(si);
474 
475 	/* search for ourselves first and take the slot if it already
476 	 * exists. Perhaps we need to mark this in a variable for our
477 	 * own journal recovery? Possibly not, though we certainly
478 	 * need to warn to the user */
479 	slot = __ocfs2_node_num_to_slot(si, osb->node_num);
480 	if (slot < 0) {
481 		/* if no slot yet, then just take 1st available
482 		 * one. */
483 		slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
484 		if (slot < 0) {
485 			spin_unlock(&osb->osb_lock);
486 			mlog(ML_ERROR, "no free slots available!\n");
487 			status = -EINVAL;
488 			goto bail;
489 		}
490 	} else
491 		printk(KERN_INFO "ocfs2: Slot %d on device (%s) was already "
492 		       "allocated to this node!\n", slot, osb->dev_str);
493 
494 	ocfs2_set_slot(si, slot, osb->node_num);
495 	osb->slot_num = slot;
496 	spin_unlock(&osb->osb_lock);
497 
498 	trace_ocfs2_find_slot(osb->slot_num);
499 
500 	status = ocfs2_update_disk_slot(osb, si, osb->slot_num);
501 	if (status < 0) {
502 		mlog_errno(status);
503 		/*
504 		 * if write block failed, invalidate slot to avoid overwrite
505 		 * slot during dismount in case another node rightly has mounted
506 		 */
507 		spin_lock(&osb->osb_lock);
508 		ocfs2_invalidate_slot(si, osb->slot_num);
509 		osb->slot_num = OCFS2_INVALID_SLOT;
510 		spin_unlock(&osb->osb_lock);
511 	}
512 
513 bail:
514 	return status;
515 }
516 
517 void ocfs2_put_slot(struct ocfs2_super *osb)
518 {
519 	int status, slot_num;
520 	struct ocfs2_slot_info *si = osb->slot_info;
521 
522 	if (!si)
523 		return;
524 
525 	spin_lock(&osb->osb_lock);
526 	ocfs2_update_slot_info(si);
527 
528 	slot_num = osb->slot_num;
529 	ocfs2_invalidate_slot(si, osb->slot_num);
530 	osb->slot_num = OCFS2_INVALID_SLOT;
531 	spin_unlock(&osb->osb_lock);
532 
533 	status = ocfs2_update_disk_slot(osb, si, slot_num);
534 	if (status < 0)
535 		mlog_errno(status);
536 
537 	ocfs2_free_slot_info(osb);
538 }
539