summaryrefslogblamecommitdiffstats
path: root/drivers/mtd/ubi/fastmap.c
blob: ead861307b3c57aac13bbb187a958a8910062904 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
























































































































































































































































































































































































































                                                                               
                              

















                                                                          






                                                                           

                                                                             
                                              









































































































































































































































































































                                                                                
                                                            
                                                      

                                              




















































































                                                                                

                                                                  
 



                                             














                                                                 












                                                                           
























































































                                                                                

                              
















                                                                                
                                                        
                                    
                                                   
 






                                                                             














































































































































































































































































































































































































                                                                                
                















                                                                              











































































































































































                                                                               
/*
 * Copyright (c) 2012 Linutronix GmbH
 * Author: Richard Weinberger <richard@nod.at>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
 * the GNU General Public License for more details.
 *
 */

#include <linux/crc32.h>
#include "ubi.h"

/**
 * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
 * @ubi: UBI device description object
 */
size_t ubi_calc_fm_size(struct ubi_device *ubi)
{
	size_t size;

	size = sizeof(struct ubi_fm_hdr) + \
		sizeof(struct ubi_fm_scan_pool) + \
		sizeof(struct ubi_fm_scan_pool) + \
		(ubi->peb_count * sizeof(struct ubi_fm_ec)) + \
		(sizeof(struct ubi_fm_eba) + \
		(ubi->peb_count * sizeof(__be32))) + \
		sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
	return roundup(size, ubi->leb_size);
}


/**
 * new_fm_vhdr - allocate a new volume header for fastmap usage.
 * @ubi: UBI device description object
 * @vol_id: the VID of the new header
 *
 * Returns a new struct ubi_vid_hdr on success.
 * NULL indicates out of memory.
 */
static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
{
	struct ubi_vid_hdr *new;

	new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
	if (!new)
		goto out;

	new->vol_type = UBI_VID_DYNAMIC;
	new->vol_id = cpu_to_be32(vol_id);

	/* UBI implementations without fastmap support have to delete the
	 * fastmap.
	 */
	new->compat = UBI_COMPAT_DELETE;

out:
	return new;
}

/**
 * add_aeb - create and add a attach erase block to a given list.
 * @ai: UBI attach info object
 * @list: the target list
 * @pnum: PEB number of the new attach erase block
 * @ec: erease counter of the new LEB
 * @scrub: scrub this PEB after attaching
 *
 * Returns 0 on success, < 0 indicates an internal error.
 */
static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
		   int pnum, int ec, int scrub)
{
	struct ubi_ainf_peb *aeb;

	aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
	if (!aeb)
		return -ENOMEM;

	aeb->pnum = pnum;
	aeb->ec = ec;
	aeb->lnum = -1;
	aeb->scrub = scrub;
	aeb->copy_flag = aeb->sqnum = 0;

	ai->ec_sum += aeb->ec;
	ai->ec_count++;

	if (ai->max_ec < aeb->ec)
		ai->max_ec = aeb->ec;

	if (ai->min_ec > aeb->ec)
		ai->min_ec = aeb->ec;

	list_add_tail(&aeb->u.list, list);

	return 0;
}

/**
 * add_vol - create and add a new volume to ubi_attach_info.
 * @ai: ubi_attach_info object
 * @vol_id: VID of the new volume
 * @used_ebs: number of used EBS
 * @data_pad: data padding value of the new volume
 * @vol_type: volume type
 * @last_eb_bytes: number of bytes in the last LEB
 *
 * Returns the new struct ubi_ainf_volume on success.
 * NULL indicates an error.
 */
static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
				       int used_ebs, int data_pad, u8 vol_type,
				       int last_eb_bytes)
{
	struct ubi_ainf_volume *av;
	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;

	while (*p) {
		parent = *p;
		av = rb_entry(parent, struct ubi_ainf_volume, rb);

		if (vol_id > av->vol_id)
			p = &(*p)->rb_left;
		else if (vol_id > av->vol_id)
			p = &(*p)->rb_right;
	}

	av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
	if (!av)
		goto out;

	av->highest_lnum = av->leb_count = 0;
	av->vol_id = vol_id;
	av->used_ebs = used_ebs;
	av->data_pad = data_pad;
	av->last_data_size = last_eb_bytes;
	av->compat = 0;
	av->vol_type = vol_type;
	av->root = RB_ROOT;

	dbg_bld("found volume (ID %i)", vol_id);

	rb_link_node(&av->rb, parent, p);
	rb_insert_color(&av->rb, &ai->volumes);

out:
	return av;
}

/**
 * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 * from it's original list.
 * @ai: ubi_attach_info object
 * @aeb: the to be assigned SEB
 * @av: target scan volume
 */
static void assign_aeb_to_av(struct ubi_attach_info *ai,
			     struct ubi_ainf_peb *aeb,
			     struct ubi_ainf_volume *av)
{
	struct ubi_ainf_peb *tmp_aeb;
	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;

	p = &av->root.rb_node;
	while (*p) {
		parent = *p;

		tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
		if (aeb->lnum != tmp_aeb->lnum) {
			if (aeb->lnum < tmp_aeb->lnum)
				p = &(*p)->rb_left;
			else
				p = &(*p)->rb_right;

			continue;
		} else
			break;
	}

	list_del(&aeb->u.list);
	av->leb_count++;

	rb_link_node(&aeb->u.rb, parent, p);
	rb_insert_color(&aeb->u.rb, &av->root);
}

/**
 * update_vol - inserts or updates a LEB which was found a pool.
 * @ubi: the UBI device object
 * @ai: attach info object
 * @av: the volume this LEB belongs to
 * @new_vh: the volume header derived from new_aeb
 * @new_aeb: the AEB to be examined
 *
 * Returns 0 on success, < 0 indicates an internal error.
 */
static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
		      struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
		      struct ubi_ainf_peb *new_aeb)
{
	struct rb_node **p = &av->root.rb_node, *parent = NULL;
	struct ubi_ainf_peb *aeb, *victim;
	int cmp_res;

	while (*p) {
		parent = *p;
		aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);

		if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
			if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
				p = &(*p)->rb_left;
			else
				p = &(*p)->rb_right;

			continue;
		}

		/* This case can happen if the fastmap gets written
		 * because of a volume change (creation, deletion, ..).
		 * Then a PEB can be within the persistent EBA and the pool.
		 */
		if (aeb->pnum == new_aeb->pnum) {
			ubi_assert(aeb->lnum == new_aeb->lnum);
			kmem_cache_free(ai->aeb_slab_cache, new_aeb);

			return 0;
		}

		cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
		if (cmp_res < 0)
			return cmp_res;

		/* new_aeb is newer */
		if (cmp_res & 1) {
			victim = kmem_cache_alloc(ai->aeb_slab_cache,
				GFP_KERNEL);
			if (!victim)
				return -ENOMEM;

			victim->ec = aeb->ec;
			victim->pnum = aeb->pnum;
			list_add_tail(&victim->u.list, &ai->erase);

			if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
				av->last_data_size = \
					be32_to_cpu(new_vh->data_size);

			dbg_bld("vol %i: AEB %i's PEB %i is the newer",
				av->vol_id, aeb->lnum, new_aeb->pnum);

			aeb->ec = new_aeb->ec;
			aeb->pnum = new_aeb->pnum;
			aeb->copy_flag = new_vh->copy_flag;
			aeb->scrub = new_aeb->scrub;
			kmem_cache_free(ai->aeb_slab_cache, new_aeb);

		/* new_aeb is older */
		} else {
			dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
				av->vol_id, aeb->lnum, new_aeb->pnum);
			list_add_tail(&new_aeb->u.list, &ai->erase);
		}

		return 0;
	}
	/* This LEB is new, let's add it to the volume */

	if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
		av->highest_lnum = be32_to_cpu(new_vh->lnum);
		av->last_data_size = be32_to_cpu(new_vh->data_size);
	}

	if (av->vol_type == UBI_STATIC_VOLUME)
		av->used_ebs = be32_to_cpu(new_vh->used_ebs);

	av->leb_count++;

	rb_link_node(&new_aeb->u.rb, parent, p);
	rb_insert_color(&new_aeb->u.rb, &av->root);

	return 0;
}

/**
 * process_pool_aeb - we found a non-empty PEB in a pool.
 * @ubi: UBI device object
 * @ai: attach info object
 * @new_vh: the volume header derived from new_aeb
 * @new_aeb: the AEB to be examined
 *
 * Returns 0 on success, < 0 indicates an internal error.
 */
static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
			    struct ubi_vid_hdr *new_vh,
			    struct ubi_ainf_peb *new_aeb)
{
	struct ubi_ainf_volume *av, *tmp_av = NULL;
	struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
	int found = 0;

	if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
		be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
		kmem_cache_free(ai->aeb_slab_cache, new_aeb);

		return 0;
	}

	/* Find the volume this SEB belongs to */
	while (*p) {
		parent = *p;
		tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);

		if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
			p = &(*p)->rb_left;
		else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
			p = &(*p)->rb_right;
		else {
			found = 1;
			break;
		}
	}

	if (found)
		av = tmp_av;
	else {
		ubi_err("orphaned volume in fastmap pool!");
		return UBI_BAD_FASTMAP;
	}

	ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);

	return update_vol(ubi, ai, av, new_vh, new_aeb);
}

/**
 * unmap_peb - unmap a PEB.
 * If fastmap detects a free PEB in the pool it has to check whether
 * this PEB has been unmapped after writing the fastmap.
 *
 * @ai: UBI attach info object
 * @pnum: The PEB to be unmapped
 */
static void unmap_peb(struct ubi_attach_info *ai, int pnum)
{
	struct ubi_ainf_volume *av;
	struct rb_node *node, *node2;
	struct ubi_ainf_peb *aeb;

	for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
		av = rb_entry(node, struct ubi_ainf_volume, rb);

		for (node2 = rb_first(&av->root); node2;
		     node2 = rb_next(node2)) {
			aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
			if (aeb->pnum == pnum) {
				rb_erase(&aeb->u.rb, &av->root);
				kmem_cache_free(ai->aeb_slab_cache, aeb);
				return;
			}
		}
	}
}

/**
 * scan_pool - scans a pool for changed (no longer empty PEBs).
 * @ubi: UBI device object
 * @ai: attach info object
 * @pebs: an array of all PEB numbers in the to be scanned pool
 * @pool_size: size of the pool (number of entries in @pebs)
 * @max_sqnum: pointer to the maximal sequence number
 * @eba_orphans: list of PEBs which need to be scanned
 * @free: list of PEBs which are most likely free (and go into @ai->free)
 *
 * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 * < 0 indicates an internal error.
 */
static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
		     int *pebs, int pool_size, unsigned long long *max_sqnum,
		     struct list_head *eba_orphans, struct list_head *free)
{
	struct ubi_vid_hdr *vh;
	struct ubi_ec_hdr *ech;
	struct ubi_ainf_peb *new_aeb, *tmp_aeb;
	int i, pnum, err, found_orphan, ret = 0;

	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
	if (!ech)
		return -ENOMEM;

	vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
	if (!vh) {
		kfree(ech);
		return -ENOMEM;
	}

	dbg_bld("scanning fastmap pool: size = %i", pool_size);

	/*
	 * Now scan all PEBs in the pool to find changes which have been made
	 * after the creation of the fastmap
	 */
	for (i = 0; i < pool_size; i++) {
		int scrub = 0;
		int image_seq;

		pnum = be32_to_cpu(pebs[i]);

		if (ubi_io_is_bad(ubi, pnum)) {
			ubi_err("bad PEB in fastmap pool!");
			ret = UBI_BAD_FASTMAP;
			goto out;
		}

		err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
		if (err && err != UBI_IO_BITFLIPS) {
			ubi_err("unable to read EC header! PEB:%i err:%i",
				pnum, err);
			ret = err > 0 ? UBI_BAD_FASTMAP : err;
			goto out;
		} else if (ret == UBI_IO_BITFLIPS)
			scrub = 1;

		/*
		 * Older UBI implementations have image_seq set to zero, so
		 * we shouldn't fail if image_seq == 0.
		 */
		image_seq = be32_to_cpu(ech->image_seq);

		if (image_seq && (image_seq != ubi->image_seq)) {
			ubi_err("bad image seq: 0x%x, expected: 0x%x",
				be32_to_cpu(ech->image_seq), ubi->image_seq);
			ret = UBI_BAD_FASTMAP;
			goto out;
		}

		err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
		if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
			unsigned long long ec = be64_to_cpu(ech->ec);
			unmap_peb(ai, pnum);
			dbg_bld("Adding PEB to free: %i", pnum);
			if (err == UBI_IO_FF_BITFLIPS)
				add_aeb(ai, free, pnum, ec, 1);
			else
				add_aeb(ai, free, pnum, ec, 0);
			continue;
		} else if (err == 0 || err == UBI_IO_BITFLIPS) {
			dbg_bld("Found non empty PEB:%i in pool", pnum);

			if (err == UBI_IO_BITFLIPS)
				scrub = 1;

			found_orphan = 0;
			list_for_each_entry(tmp_aeb, eba_orphans, u.list) {
				if (tmp_aeb->pnum == pnum) {
					found_orphan = 1;
					break;
				}
			}
			if (found_orphan) {
				kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
				list_del(&tmp_aeb->u.list);
			}

			new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
						   GFP_KERNEL);
			if (!new_aeb) {
				ret = -ENOMEM;
				goto out;
			}

			new_aeb->ec = be64_to_cpu(ech->ec);
			new_aeb->pnum = pnum;
			new_aeb->lnum = be32_to_cpu(vh->lnum);
			new_aeb->sqnum = be64_to_cpu(vh->sqnum);
			new_aeb->copy_flag = vh->copy_flag;
			new_aeb->scrub = scrub;

			if (*max_sqnum < new_aeb->sqnum)
				*max_sqnum = new_aeb->sqnum;

			err = process_pool_aeb(ubi, ai, vh, new_aeb);
			if (err) {
				ret = err > 0 ? UBI_BAD_FASTMAP : err;
				goto out;
			}
		} else {
			/* We are paranoid and fall back to scanning mode */
			ubi_err("fastmap pool PEBs contains damaged PEBs!");
			ret = err > 0 ? UBI_BAD_FASTMAP : err;
			goto out;
		}

	}

out:
	ubi_free_vid_hdr(ubi, vh);
	kfree(ech);
	return ret;
}

/**
 * count_fastmap_pebs - Counts the PEBs found by fastmap.
 * @ai: The UBI attach info object
 */
static int count_fastmap_pebs(struct ubi_attach_info *ai)
{
	struct ubi_ainf_peb *aeb;
	struct ubi_ainf_volume *av;
	struct rb_node *rb1, *rb2;
	int n = 0;

	list_for_each_entry(aeb, &ai->erase, u.list)
		n++;

	list_for_each_entry(aeb, &ai->free, u.list)
		n++;

	 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
		ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
			n++;

	return n;
}

/**
 * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 * @ubi: UBI device object
 * @ai: UBI attach info object
 * @fm: the fastmap to be attached
 *
 * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 * < 0 indicates an internal error.
 */
static int ubi_attach_fastmap(struct ubi_device *ubi,
			      struct ubi_attach_info *ai,
			      struct ubi_fastmap_layout *fm)
{
	struct list_head used, eba_orphans, free;
	struct ubi_ainf_volume *av;
	struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
	struct ubi_ec_hdr *ech;
	struct ubi_fm_sb *fmsb;
	struct ubi_fm_hdr *fmhdr;
	struct ubi_fm_scan_pool *fmpl1, *fmpl2;
	struct ubi_fm_ec *fmec;
	struct ubi_fm_volhdr *fmvhdr;
	struct ubi_fm_eba *fm_eba;
	int ret, i, j, pool_size, wl_pool_size;
	size_t fm_pos = 0, fm_size = ubi->fm_size;
	unsigned long long max_sqnum = 0;
	void *fm_raw = ubi->fm_buf;

	INIT_LIST_HEAD(&used);
	INIT_LIST_HEAD(&free);
	INIT_LIST_HEAD(&eba_orphans);
	INIT_LIST_HEAD(&ai->corr);
	INIT_LIST_HEAD(&ai->free);
	INIT_LIST_HEAD(&ai->erase);
	INIT_LIST_HEAD(&ai->alien);
	ai->volumes = RB_ROOT;
	ai->min_ec = UBI_MAX_ERASECOUNTER;

	ai->aeb_slab_cache = kmem_cache_create("ubi_ainf_peb_slab",
					       sizeof(struct ubi_ainf_peb),
					       0, 0, NULL);
	if (!ai->aeb_slab_cache) {
		ret = -ENOMEM;
		goto fail;
	}

	fmsb = (struct ubi_fm_sb *)(fm_raw);
	ai->max_sqnum = fmsb->sqnum;
	fm_pos += sizeof(struct ubi_fm_sb);
	if (fm_pos >= fm_size)
		goto fail_bad;

	fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
	fm_pos += sizeof(*fmhdr);
	if (fm_pos >= fm_size)
		goto fail_bad;

	if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
		ubi_err("bad fastmap header magic: 0x%x, expected: 0x%x",
			be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
		goto fail_bad;
	}

	fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
	fm_pos += sizeof(*fmpl1);
	if (fm_pos >= fm_size)
		goto fail_bad;
	if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
		ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
			be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
		goto fail_bad;
	}

	fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
	fm_pos += sizeof(*fmpl2);
	if (fm_pos >= fm_size)
		goto fail_bad;
	if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
		ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
			be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
		goto fail_bad;
	}

	pool_size = be16_to_cpu(fmpl1->size);
	wl_pool_size = be16_to_cpu(fmpl2->size);
	fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
	fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);

	if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
		ubi_err("bad pool size: %i", pool_size);
		goto fail_bad;
	}

	if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
		ubi_err("bad WL pool size: %i", wl_pool_size);
		goto fail_bad;
	}


	if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
	    fm->max_pool_size < 0) {
		ubi_err("bad maximal pool size: %i", fm->max_pool_size);
		goto fail_bad;
	}

	if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
	    fm->max_wl_pool_size < 0) {
		ubi_err("bad maximal WL pool size: %i", fm->max_wl_pool_size);
		goto fail_bad;
	}

	/* read EC values from free list */
	for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
		fm_pos += sizeof(*fmec);
		if (fm_pos >= fm_size)
			goto fail_bad;

		add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
			be32_to_cpu(fmec->ec), 0);
	}

	/* read EC values from used list */
	for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
		fm_pos += sizeof(*fmec);
		if (fm_pos >= fm_size)
			goto fail_bad;

		add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
			be32_to_cpu(fmec->ec), 0);
	}

	/* read EC values from scrub list */
	for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
		fm_pos += sizeof(*fmec);
		if (fm_pos >= fm_size)
			goto fail_bad;

		add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
			be32_to_cpu(fmec->ec), 1);
	}

	/* read EC values from erase list */
	for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
		fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
		fm_pos += sizeof(*fmec);
		if (fm_pos >= fm_size)
			goto fail_bad;

		add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
			be32_to_cpu(fmec->ec), 1);
	}

	ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
	ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);

	/* Iterate over all volumes and read their EBA table */
	for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
		fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
		fm_pos += sizeof(*fmvhdr);
		if (fm_pos >= fm_size)
			goto fail_bad;

		if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
			ubi_err("bad fastmap vol header magic: 0x%x, " \
				"expected: 0x%x",
				be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
			goto fail_bad;
		}

		av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
			     be32_to_cpu(fmvhdr->used_ebs),
			     be32_to_cpu(fmvhdr->data_pad),
			     fmvhdr->vol_type,
			     be32_to_cpu(fmvhdr->last_eb_bytes));

		if (!av)
			goto fail_bad;

		ai->vols_found++;
		if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
			ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);

		fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
		fm_pos += sizeof(*fm_eba);
		fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
		if (fm_pos >= fm_size)
			goto fail_bad;

		if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
			ubi_err("bad fastmap EBA header magic: 0x%x, " \
				"expected: 0x%x",
				be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
			goto fail_bad;
		}

		for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
			int pnum = be32_to_cpu(fm_eba->pnum[j]);

			if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
				continue;

			aeb = NULL;
			list_for_each_entry(tmp_aeb, &used, u.list) {
				if (tmp_aeb->pnum == pnum) {
					aeb = tmp_aeb;
					break;
				}
			}

			/* This can happen if a PEB is already in an EBA known
			 * by this fastmap but the PEB itself is not in the used
			 * list.
			 * In this case the PEB can be within the fastmap pool
			 * or while writing the fastmap it was in the protection
			 * queue.
			 */
			if (!aeb) {
				aeb = kmem_cache_alloc(ai->aeb_slab_cache,
						       GFP_KERNEL);
				if (!aeb) {
					ret = -ENOMEM;

					goto fail;
				}

				aeb->lnum = j;
				aeb->pnum = be32_to_cpu(fm_eba->pnum[j]);
				aeb->ec = -1;
				aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
				list_add_tail(&aeb->u.list, &eba_orphans);
				continue;
			}

			aeb->lnum = j;

			if (av->highest_lnum <= aeb->lnum)
				av->highest_lnum = aeb->lnum;

			assign_aeb_to_av(ai, aeb, av);

			dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
				aeb->pnum, aeb->lnum, av->vol_id);
		}

		ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
		if (!ech) {
			ret = -ENOMEM;
			goto fail;
		}

		list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans,
					 u.list) {
			int err;

			if (ubi_io_is_bad(ubi, tmp_aeb->pnum)) {
				ubi_err("bad PEB in fastmap EBA orphan list");
				ret = UBI_BAD_FASTMAP;
				kfree(ech);
				goto fail;
			}

			err = ubi_io_read_ec_hdr(ubi, tmp_aeb->pnum, ech, 0);
			if (err && err != UBI_IO_BITFLIPS) {
				ubi_err("unable to read EC header! PEB:%i " \
					"err:%i", tmp_aeb->pnum, err);
				ret = err > 0 ? UBI_BAD_FASTMAP : err;
				kfree(ech);

				goto fail;
			} else if (err == UBI_IO_BITFLIPS)
				tmp_aeb->scrub = 1;

			tmp_aeb->ec = be64_to_cpu(ech->ec);
			assign_aeb_to_av(ai, tmp_aeb, av);
		}

		kfree(ech);
	}

	ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum,
			&eba_orphans, &free);
	if (ret)
		goto fail;

	ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum,
			&eba_orphans, &free);
	if (ret)
		goto fail;

	if (max_sqnum > ai->max_sqnum)
		ai->max_sqnum = max_sqnum;

	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
		list_move_tail(&tmp_aeb->u.list, &ai->free);

	ubi_assert(list_empty(&used));
	ubi_assert(list_empty(&eba_orphans));
	ubi_assert(list_empty(&free));

	/*
	 * If fastmap is leaking PEBs (must not happen), raise a
	 * fat warning and fall back to scanning mode.
	 * We do this here because in ubi_wl_init() it's too late
	 * and we cannot fall back to scanning.
	 */
	if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
		    ai->bad_peb_count - fm->used_blocks))
		goto fail_bad;

	return 0;

fail_bad:
	ret = UBI_BAD_FASTMAP;
fail:
	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
		list_del(&tmp_aeb->u.list);
	}
	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans, u.list) {
		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
		list_del(&tmp_aeb->u.list);
	}
	list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
		kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
		list_del(&tmp_aeb->u.list);
	}

	return ret;
}

/**
 * ubi_scan_fastmap - scan the fastmap.
 * @ubi: UBI device object
 * @ai: UBI attach info to be filled
 * @fm_anchor: The fastmap starts at this PEB
 *
 * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 * UBI_BAD_FASTMAP if one was found but is not usable.
 * < 0 indicates an internal error.
 */
int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
		     int fm_anchor)
{
	struct ubi_fm_sb *fmsb, *fmsb2;
	struct ubi_vid_hdr *vh;
	struct ubi_ec_hdr *ech;
	struct ubi_fastmap_layout *fm;
	int i, used_blocks, pnum, ret = 0;
	size_t fm_size;
	__be32 crc, tmp_crc;
	unsigned long long sqnum = 0;

	mutex_lock(&ubi->fm_mutex);
	memset(ubi->fm_buf, 0, ubi->fm_size);

	fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
	if (!fmsb) {
		ret = -ENOMEM;
		goto out;
	}

	fm = kzalloc(sizeof(*fm), GFP_KERNEL);
	if (!fm) {
		ret = -ENOMEM;
		kfree(fmsb);
		goto out;
	}

	ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
	if (ret && ret != UBI_IO_BITFLIPS)
		goto free_fm_sb;
	else if (ret == UBI_IO_BITFLIPS)
		fm->to_be_tortured[0] = 1;

	if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
		ubi_err("bad super block magic: 0x%x, expected: 0x%x",
			be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
		ret = UBI_BAD_FASTMAP;
		goto free_fm_sb;
	}

	if (fmsb->version != UBI_FM_FMT_VERSION) {
		ubi_err("bad fastmap version: %i, expected: %i",
			fmsb->version, UBI_FM_FMT_VERSION);
		ret = UBI_BAD_FASTMAP;
		goto free_fm_sb;
	}

	used_blocks = be32_to_cpu(fmsb->used_blocks);
	if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
		ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
		ret = UBI_BAD_FASTMAP;
		goto free_fm_sb;
	}

	fm_size = ubi->leb_size * used_blocks;
	if (fm_size != ubi->fm_size) {
		ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
			ubi->fm_size);
		ret = UBI_BAD_FASTMAP;
		goto free_fm_sb;
	}

	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
	if (!ech) {
		ret = -ENOMEM;
		goto free_fm_sb;
	}

	vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
	if (!vh) {
		ret = -ENOMEM;
		goto free_hdr;
	}

	for (i = 0; i < used_blocks; i++) {
		int image_seq;

		pnum = be32_to_cpu(fmsb->block_loc[i]);

		if (ubi_io_is_bad(ubi, pnum)) {
			ret = UBI_BAD_FASTMAP;
			goto free_hdr;
		}

		ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
		if (ret && ret != UBI_IO_BITFLIPS) {
			ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
				i, pnum);
			if (ret > 0)
				ret = UBI_BAD_FASTMAP;
			goto free_hdr;
		} else if (ret == UBI_IO_BITFLIPS)
			fm->to_be_tortured[i] = 1;

		image_seq = be32_to_cpu(ech->image_seq);
		if (!ubi->image_seq)
			ubi->image_seq = image_seq;

		/*
		 * Older UBI implementations have image_seq set to zero, so
		 * we shouldn't fail if image_seq == 0.
		 */
		if (image_seq && (image_seq != ubi->image_seq)) {
			ubi_err("wrong image seq:%d instead of %d",
				be32_to_cpu(ech->image_seq), ubi->image_seq);
			ret = UBI_BAD_FASTMAP;
			goto free_hdr;
		}

		ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
		if (ret && ret != UBI_IO_BITFLIPS) {
			ubi_err("unable to read fastmap block# %i (PEB: %i)",
				i, pnum);
			goto free_hdr;
		}

		if (i == 0) {
			if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
				ubi_err("bad fastmap anchor vol_id: 0x%x," \
					" expected: 0x%x",
					be32_to_cpu(vh->vol_id),
					UBI_FM_SB_VOLUME_ID);
				ret = UBI_BAD_FASTMAP;
				goto free_hdr;
			}
		} else {
			if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
				ubi_err("bad fastmap data vol_id: 0x%x," \
					" expected: 0x%x",
					be32_to_cpu(vh->vol_id),
					UBI_FM_DATA_VOLUME_ID);
				ret = UBI_BAD_FASTMAP;
				goto free_hdr;
			}
		}

		if (sqnum < be64_to_cpu(vh->sqnum))
			sqnum = be64_to_cpu(vh->sqnum);

		ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
				  ubi->leb_start, ubi->leb_size);
		if (ret && ret != UBI_IO_BITFLIPS) {
			ubi_err("unable to read fastmap block# %i (PEB: %i, " \
				"err: %i)", i, pnum, ret);
			goto free_hdr;
		}
	}

	kfree(fmsb);
	fmsb = NULL;

	fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
	tmp_crc = be32_to_cpu(fmsb2->data_crc);
	fmsb2->data_crc = 0;
	crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
	if (crc != tmp_crc) {
		ubi_err("fastmap data CRC is invalid");
		ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
		ret = UBI_BAD_FASTMAP;
		goto free_hdr;
	}

	fmsb2->sqnum = sqnum;

	fm->used_blocks = used_blocks;

	ret = ubi_attach_fastmap(ubi, ai, fm);
	if (ret) {
		if (ret > 0)
			ret = UBI_BAD_FASTMAP;
		goto free_hdr;
	}

	for (i = 0; i < used_blocks; i++) {
		struct ubi_wl_entry *e;

		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
		if (!e) {
			while (i--)
				kfree(fm->e[i]);

			ret = -ENOMEM;
			goto free_hdr;
		}

		e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
		e->ec = be32_to_cpu(fmsb2->block_ec[i]);
		fm->e[i] = e;
	}

	ubi->fm = fm;
	ubi->fm_pool.max_size = ubi->fm->max_pool_size;
	ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
	ubi_msg("attached by fastmap");
	ubi_msg("fastmap pool size: %d", ubi->fm_pool.max_size);
	ubi_msg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
	ubi->fm_disabled = 0;

	ubi_free_vid_hdr(ubi, vh);
	kfree(ech);
out:
	mutex_unlock(&ubi->fm_mutex);
	if (ret == UBI_BAD_FASTMAP)
		ubi_err("Attach by fastmap failed, doing a full scan!");
	return ret;

free_hdr:
	ubi_free_vid_hdr(ubi, vh);
	kfree(ech);
free_fm_sb:
	kfree(fmsb);
	kfree(fm);
	goto out;
}

/**
 * ubi_write_fastmap - writes a fastmap.
 * @ubi: UBI device object
 * @new_fm: the to be written fastmap
 *
 * Returns 0 on success, < 0 indicates an internal error.
 */
static int ubi_write_fastmap(struct ubi_device *ubi,
			     struct ubi_fastmap_layout *new_fm)
{
	size_t fm_pos = 0;
	void *fm_raw;
	struct ubi_fm_sb *fmsb;
	struct ubi_fm_hdr *fmh;
	struct ubi_fm_scan_pool *fmpl1, *fmpl2;
	struct ubi_fm_ec *fec;
	struct ubi_fm_volhdr *fvh;
	struct ubi_fm_eba *feba;
	struct rb_node *node;
	struct ubi_wl_entry *wl_e;
	struct ubi_volume *vol;
	struct ubi_vid_hdr *avhdr, *dvhdr;
	struct ubi_work *ubi_wrk;
	int ret, i, j, free_peb_count, used_peb_count, vol_count;
	int scrub_peb_count, erase_peb_count;

	fm_raw = ubi->fm_buf;
	memset(ubi->fm_buf, 0, ubi->fm_size);

	avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
	if (!avhdr) {
		ret = -ENOMEM;
		goto out;
	}

	dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
	if (!dvhdr) {
		ret = -ENOMEM;
		goto out_kfree;
	}

	spin_lock(&ubi->volumes_lock);
	spin_lock(&ubi->wl_lock);

	fmsb = (struct ubi_fm_sb *)fm_raw;
	fm_pos += sizeof(*fmsb);
	ubi_assert(fm_pos <= ubi->fm_size);

	fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
	fm_pos += sizeof(*fmh);
	ubi_assert(fm_pos <= ubi->fm_size);

	fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
	fmsb->version = UBI_FM_FMT_VERSION;
	fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
	/* the max sqnum will be filled in while *reading* the fastmap */
	fmsb->sqnum = 0;

	fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
	free_peb_count = 0;
	used_peb_count = 0;
	scrub_peb_count = 0;
	erase_peb_count = 0;
	vol_count = 0;

	fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
	fm_pos += sizeof(*fmpl1);
	fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
	fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
	fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);

	for (i = 0; i < ubi->fm_pool.size; i++)
		fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);

	fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
	fm_pos += sizeof(*fmpl2);
	fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
	fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
	fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);

	for (i = 0; i < ubi->fm_wl_pool.size; i++)
		fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);

	for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
		wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);

		fec->pnum = cpu_to_be32(wl_e->pnum);
		fec->ec = cpu_to_be32(wl_e->ec);

		free_peb_count++;
		fm_pos += sizeof(*fec);
		ubi_assert(fm_pos <= ubi->fm_size);
	}
	fmh->free_peb_count = cpu_to_be32(free_peb_count);

	for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
		wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);

		fec->pnum = cpu_to_be32(wl_e->pnum);
		fec->ec = cpu_to_be32(wl_e->ec);

		used_peb_count++;
		fm_pos += sizeof(*fec);
		ubi_assert(fm_pos <= ubi->fm_size);
	}
	fmh->used_peb_count = cpu_to_be32(used_peb_count);

	for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
		wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
		fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);

		fec->pnum = cpu_to_be32(wl_e->pnum);
		fec->ec = cpu_to_be32(wl_e->ec);

		scrub_peb_count++;
		fm_pos += sizeof(*fec);
		ubi_assert(fm_pos <= ubi->fm_size);
	}
	fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);


	list_for_each_entry(ubi_wrk, &ubi->works, list) {
		if (ubi_is_erase_work(ubi_wrk)) {
			wl_e = ubi_wrk->e;
			ubi_assert(wl_e);

			fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);

			fec->pnum = cpu_to_be32(wl_e->pnum);
			fec->ec = cpu_to_be32(wl_e->ec);

			erase_peb_count++;
			fm_pos += sizeof(*fec);
			ubi_assert(fm_pos <= ubi->fm_size);
		}
	}
	fmh->erase_peb_count = cpu_to_be32(erase_peb_count);

	for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
		vol = ubi->volumes[i];

		if (!vol)
			continue;

		vol_count++;

		fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
		fm_pos += sizeof(*fvh);
		ubi_assert(fm_pos <= ubi->fm_size);

		fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
		fvh->vol_id = cpu_to_be32(vol->vol_id);
		fvh->vol_type = vol->vol_type;
		fvh->used_ebs = cpu_to_be32(vol->used_ebs);
		fvh->data_pad = cpu_to_be32(vol->data_pad);
		fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);

		ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
			vol->vol_type == UBI_STATIC_VOLUME);

		feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
		fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
		ubi_assert(fm_pos <= ubi->fm_size);

		for (j = 0; j < vol->reserved_pebs; j++)
			feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);

		feba->reserved_pebs = cpu_to_be32(j);
		feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
	}
	fmh->vol_count = cpu_to_be32(vol_count);
	fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);

	avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
	avhdr->lnum = 0;

	spin_unlock(&ubi->wl_lock);
	spin_unlock(&ubi->volumes_lock);

	dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
	ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
	if (ret) {
		ubi_err("unable to write vid_hdr to fastmap SB!");
		goto out_kfree;
	}

	for (i = 0; i < new_fm->used_blocks; i++) {
		fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
		fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
	}

	fmsb->data_crc = 0;
	fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
					   ubi->fm_size));

	for (i = 1; i < new_fm->used_blocks; i++) {
		dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
		dvhdr->lnum = cpu_to_be32(i);
		dbg_bld("writing fastmap data to PEB %i sqnum %llu",
			new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
		ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
		if (ret) {
			ubi_err("unable to write vid_hdr to PEB %i!",
				new_fm->e[i]->pnum);
			goto out_kfree;
		}
	}

	for (i = 0; i < new_fm->used_blocks; i++) {
		ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
			new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
		if (ret) {
			ubi_err("unable to write fastmap to PEB %i!",
				new_fm->e[i]->pnum);
			goto out_kfree;
		}
	}

	ubi_assert(new_fm);
	ubi->fm = new_fm;

	dbg_bld("fastmap written!");

out_kfree:
	ubi_free_vid_hdr(ubi, avhdr);
	ubi_free_vid_hdr(ubi, dvhdr);
out:
	return ret;
}

/**
 * erase_block - Manually erase a PEB.
 * @ubi: UBI device object
 * @pnum: PEB to be erased
 *
 * Returns the new EC value on success, < 0 indicates an internal error.
 */
static int erase_block(struct ubi_device *ubi, int pnum)
{
	int ret;
	struct ubi_ec_hdr *ec_hdr;
	long long ec;

	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
	if (!ec_hdr)
		return -ENOMEM;

	ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
	if (ret < 0)
		goto out;
	else if (ret && ret != UBI_IO_BITFLIPS) {
		ret = -EINVAL;
		goto out;
	}

	ret = ubi_io_sync_erase(ubi, pnum, 0);
	if (ret < 0)
		goto out;

	ec = be64_to_cpu(ec_hdr->ec);
	ec += ret;
	if (ec > UBI_MAX_ERASECOUNTER) {
		ret = -EINVAL;
		goto out;
	}

	ec_hdr->ec = cpu_to_be64(ec);
	ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
	if (ret < 0)
		goto out;

	ret = ec;
out:
	kfree(ec_hdr);
	return ret;
}

/**
 * invalidate_fastmap - destroys a fastmap.
 * @ubi: UBI device object
 * @fm: the fastmap to be destroyed
 *
 * Returns 0 on success, < 0 indicates an internal error.
 */
static int invalidate_fastmap(struct ubi_device *ubi,
			      struct ubi_fastmap_layout *fm)
{
	int ret;
	struct ubi_vid_hdr *vh;

	ret = erase_block(ubi, fm->e[0]->pnum);
	if (ret < 0)
		return ret;

	vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
	if (!vh)
		return -ENOMEM;

	/* deleting the current fastmap SB is not enough, an old SB may exist,
	 * so create a (corrupted) SB such that fastmap will find it and fall
	 * back to scanning mode in any case */
	vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
	ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);

	return ret;
}

/**
 * ubi_update_fastmap - will be called by UBI if a volume changes or
 * a fastmap pool becomes full.
 * @ubi: UBI device object
 *
 * Returns 0 on success, < 0 indicates an internal error.
 */
int ubi_update_fastmap(struct ubi_device *ubi)
{
	int ret, i;
	struct ubi_fastmap_layout *new_fm, *old_fm;
	struct ubi_wl_entry *tmp_e;

	mutex_lock(&ubi->fm_mutex);

	ubi_refill_pools(ubi);

	if (ubi->ro_mode || ubi->fm_disabled) {
		mutex_unlock(&ubi->fm_mutex);
		return 0;
	}

	ret = ubi_ensure_anchor_pebs(ubi);
	if (ret) {
		mutex_unlock(&ubi->fm_mutex);
		return ret;
	}

	new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
	if (!new_fm) {
		mutex_unlock(&ubi->fm_mutex);
		return -ENOMEM;
	}

	new_fm->used_blocks = ubi->fm_size / ubi->leb_size;

	for (i = 0; i < new_fm->used_blocks; i++) {
		new_fm->e[i] = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
		if (!new_fm->e[i]) {
			while (i--)
				kfree(new_fm->e[i]);

			kfree(new_fm);
			mutex_unlock(&ubi->fm_mutex);
			return -ENOMEM;
		}
	}

	old_fm = ubi->fm;
	ubi->fm = NULL;

	if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
		ubi_err("fastmap too large");
		ret = -ENOSPC;
		goto err;
	}

	for (i = 1; i < new_fm->used_blocks; i++) {
		spin_lock(&ubi->wl_lock);
		tmp_e = ubi_wl_get_fm_peb(ubi, 0);
		spin_unlock(&ubi->wl_lock);

		if (!tmp_e && !old_fm) {
			int j;
			ubi_err("could not get any free erase block");

			for (j = 1; j < i; j++)
				ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);

			ret = -ENOSPC;
			goto err;
		} else if (!tmp_e && old_fm) {
			ret = erase_block(ubi, old_fm->e[i]->pnum);
			if (ret < 0) {
				int j;

				for (j = 1; j < i; j++)
					ubi_wl_put_fm_peb(ubi, new_fm->e[j],
							  j, 0);

				ubi_err("could not erase old fastmap PEB");
				goto err;
			}

			new_fm->e[i]->pnum = old_fm->e[i]->pnum;
			new_fm->e[i]->ec = old_fm->e[i]->ec;
		} else {
			new_fm->e[i]->pnum = tmp_e->pnum;
			new_fm->e[i]->ec = tmp_e->ec;

			if (old_fm)
				ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
						  old_fm->to_be_tortured[i]);
		}
	}

	spin_lock(&ubi->wl_lock);
	tmp_e = ubi_wl_get_fm_peb(ubi, 1);
	spin_unlock(&ubi->wl_lock);

	if (old_fm) {
		/* no fresh anchor PEB was found, reuse the old one */
		if (!tmp_e) {
			ret = erase_block(ubi, old_fm->e[0]->pnum);
			if (ret < 0) {
				int i;
				ubi_err("could not erase old anchor PEB");

				for (i = 1; i < new_fm->used_blocks; i++)
					ubi_wl_put_fm_peb(ubi, new_fm->e[i],
							  i, 0);
				goto err;
			}

			new_fm->e[0]->pnum = old_fm->e[0]->pnum;
			new_fm->e[0]->ec = ret;
		} else {
			/* we've got a new anchor PEB, return the old one */
			ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
					  old_fm->to_be_tortured[0]);

			new_fm->e[0]->pnum = tmp_e->pnum;
			new_fm->e[0]->ec = tmp_e->ec;
		}
	} else {
		if (!tmp_e) {
			int i;
			ubi_err("could not find any anchor PEB");

			for (i = 1; i < new_fm->used_blocks; i++)
				ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);

			ret = -ENOSPC;
			goto err;
		}

		new_fm->e[0]->pnum = tmp_e->pnum;
		new_fm->e[0]->ec = tmp_e->ec;
	}

	down_write(&ubi->work_sem);
	down_write(&ubi->fm_sem);
	ret = ubi_write_fastmap(ubi, new_fm);
	up_write(&ubi->fm_sem);
	up_write(&ubi->work_sem);

	if (ret)
		goto err;

out_unlock:
	mutex_unlock(&ubi->fm_mutex);
	kfree(old_fm);
	return ret;

err:
	kfree(new_fm);

	ubi_warn("Unable to write new fastmap, err=%i", ret);

	ret = 0;
	if (old_fm) {
		ret = invalidate_fastmap(ubi, old_fm);
		if (ret < 0)
			ubi_err("Unable to invalidiate current fastmap!");
		else if (ret)
			ret = 0;
	}
	goto out_unlock;
}