1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * This file is part of UBIFS.
4 *
5 * Copyright (C) 2006-2008 Nokia Corporation.
6 *
7 * Authors: Artem Bityutskiy (Битюцкий Артём)
8 * Adrian Hunter
9 */
10
11 /* This file implements reading and writing the master node */
12
13 #include "ubifs.h"
14 #ifdef __UBOOT__
15 #include <log.h>
16 #include <dm/devres.h>
17 #include <linux/compat.h>
18 #include <linux/err.h>
19 #include <ubi_uboot.h>
20 #endif
21
22 /**
23 * scan_for_master - search the valid master node.
24 * @c: UBIFS file-system description object
25 *
26 * This function scans the master node LEBs and search for the latest master
27 * node. Returns zero in case of success, %-EUCLEAN if there master area is
28 * corrupted and requires recovery, and a negative error code in case of
29 * failure.
30 */
scan_for_master(struct ubifs_info * c)31 static int scan_for_master(struct ubifs_info *c)
32 {
33 struct ubifs_scan_leb *sleb;
34 struct ubifs_scan_node *snod;
35 int lnum, offs = 0, nodes_cnt;
36
37 lnum = UBIFS_MST_LNUM;
38
39 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
40 if (IS_ERR(sleb))
41 return PTR_ERR(sleb);
42 nodes_cnt = sleb->nodes_cnt;
43 if (nodes_cnt > 0) {
44 snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
45 list);
46 if (snod->type != UBIFS_MST_NODE)
47 goto out_dump;
48 memcpy(c->mst_node, snod->node, snod->len);
49 offs = snod->offs;
50 }
51 ubifs_scan_destroy(sleb);
52
53 lnum += 1;
54
55 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
56 if (IS_ERR(sleb))
57 return PTR_ERR(sleb);
58 if (sleb->nodes_cnt != nodes_cnt)
59 goto out;
60 if (!sleb->nodes_cnt)
61 goto out;
62 snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
63 if (snod->type != UBIFS_MST_NODE)
64 goto out_dump;
65 if (snod->offs != offs)
66 goto out;
67 if (memcmp((void *)c->mst_node + UBIFS_CH_SZ,
68 (void *)snod->node + UBIFS_CH_SZ,
69 UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
70 goto out;
71 c->mst_offs = offs;
72 ubifs_scan_destroy(sleb);
73 return 0;
74
75 out:
76 ubifs_scan_destroy(sleb);
77 return -EUCLEAN;
78
79 out_dump:
80 ubifs_err(c, "unexpected node type %d master LEB %d:%d",
81 snod->type, lnum, snod->offs);
82 ubifs_scan_destroy(sleb);
83 return -EINVAL;
84 }
85
86 /**
87 * validate_master - validate master node.
88 * @c: UBIFS file-system description object
89 *
90 * This function validates data which was read from master node. Returns zero
91 * if the data is all right and %-EINVAL if not.
92 */
validate_master(const struct ubifs_info * c)93 static int validate_master(const struct ubifs_info *c)
94 {
95 long long main_sz;
96 int err;
97
98 if (c->max_sqnum >= SQNUM_WATERMARK) {
99 err = 1;
100 goto out;
101 }
102
103 if (c->cmt_no >= c->max_sqnum) {
104 err = 2;
105 goto out;
106 }
107
108 if (c->highest_inum >= INUM_WATERMARK) {
109 err = 3;
110 goto out;
111 }
112
113 if (c->lhead_lnum < UBIFS_LOG_LNUM ||
114 c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs ||
115 c->lhead_offs < 0 || c->lhead_offs >= c->leb_size ||
116 c->lhead_offs & (c->min_io_size - 1)) {
117 err = 4;
118 goto out;
119 }
120
121 if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first ||
122 c->zroot.offs >= c->leb_size || c->zroot.offs & 7) {
123 err = 5;
124 goto out;
125 }
126
127 if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len ||
128 c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) {
129 err = 6;
130 goto out;
131 }
132
133 if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) {
134 err = 7;
135 goto out;
136 }
137
138 if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first ||
139 c->ihead_offs % c->min_io_size || c->ihead_offs < 0 ||
140 c->ihead_offs > c->leb_size || c->ihead_offs & 7) {
141 err = 8;
142 goto out;
143 }
144
145 main_sz = (long long)c->main_lebs * c->leb_size;
146 if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) {
147 err = 9;
148 goto out;
149 }
150
151 if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last ||
152 c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) {
153 err = 10;
154 goto out;
155 }
156
157 if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last ||
158 c->nhead_offs < 0 || c->nhead_offs % c->min_io_size ||
159 c->nhead_offs > c->leb_size) {
160 err = 11;
161 goto out;
162 }
163
164 if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last ||
165 c->ltab_offs < 0 ||
166 c->ltab_offs + c->ltab_sz > c->leb_size) {
167 err = 12;
168 goto out;
169 }
170
171 if (c->big_lpt && (c->lsave_lnum < c->lpt_first ||
172 c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 ||
173 c->lsave_offs + c->lsave_sz > c->leb_size)) {
174 err = 13;
175 goto out;
176 }
177
178 if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) {
179 err = 14;
180 goto out;
181 }
182
183 if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) {
184 err = 15;
185 goto out;
186 }
187
188 if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) {
189 err = 16;
190 goto out;
191 }
192
193 if (c->lst.total_free < 0 || c->lst.total_free > main_sz ||
194 c->lst.total_free & 7) {
195 err = 17;
196 goto out;
197 }
198
199 if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) {
200 err = 18;
201 goto out;
202 }
203
204 if (c->lst.total_used < 0 || (c->lst.total_used & 7)) {
205 err = 19;
206 goto out;
207 }
208
209 if (c->lst.total_free + c->lst.total_dirty +
210 c->lst.total_used > main_sz) {
211 err = 20;
212 goto out;
213 }
214
215 if (c->lst.total_dead + c->lst.total_dark +
216 c->lst.total_used + c->bi.old_idx_sz > main_sz) {
217 err = 21;
218 goto out;
219 }
220
221 if (c->lst.total_dead < 0 ||
222 c->lst.total_dead > c->lst.total_free + c->lst.total_dirty ||
223 c->lst.total_dead & 7) {
224 err = 22;
225 goto out;
226 }
227
228 if (c->lst.total_dark < 0 ||
229 c->lst.total_dark > c->lst.total_free + c->lst.total_dirty ||
230 c->lst.total_dark & 7) {
231 err = 23;
232 goto out;
233 }
234
235 return 0;
236
237 out:
238 ubifs_err(c, "bad master node at offset %d error %d", c->mst_offs, err);
239 ubifs_dump_node(c, c->mst_node);
240 return -EINVAL;
241 }
242
243 /**
244 * ubifs_read_master - read master node.
245 * @c: UBIFS file-system description object
246 *
247 * This function finds and reads the master node during file-system mount. If
248 * the flash is empty, it creates default master node as well. Returns zero in
249 * case of success and a negative error code in case of failure.
250 */
ubifs_read_master(struct ubifs_info * c)251 int ubifs_read_master(struct ubifs_info *c)
252 {
253 int err, old_leb_cnt;
254
255 c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL);
256 if (!c->mst_node)
257 return -ENOMEM;
258
259 err = scan_for_master(c);
260 if (err) {
261 if (err == -EUCLEAN)
262 err = ubifs_recover_master_node(c);
263 if (err)
264 /*
265 * Note, we do not free 'c->mst_node' here because the
266 * unmount routine will take care of this.
267 */
268 return err;
269 }
270
271 /* Make sure that the recovery flag is clear */
272 c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY);
273
274 c->max_sqnum = le64_to_cpu(c->mst_node->ch.sqnum);
275 c->highest_inum = le64_to_cpu(c->mst_node->highest_inum);
276 c->cmt_no = le64_to_cpu(c->mst_node->cmt_no);
277 c->zroot.lnum = le32_to_cpu(c->mst_node->root_lnum);
278 c->zroot.offs = le32_to_cpu(c->mst_node->root_offs);
279 c->zroot.len = le32_to_cpu(c->mst_node->root_len);
280 c->lhead_lnum = le32_to_cpu(c->mst_node->log_lnum);
281 c->gc_lnum = le32_to_cpu(c->mst_node->gc_lnum);
282 c->ihead_lnum = le32_to_cpu(c->mst_node->ihead_lnum);
283 c->ihead_offs = le32_to_cpu(c->mst_node->ihead_offs);
284 c->bi.old_idx_sz = le64_to_cpu(c->mst_node->index_size);
285 c->lpt_lnum = le32_to_cpu(c->mst_node->lpt_lnum);
286 c->lpt_offs = le32_to_cpu(c->mst_node->lpt_offs);
287 c->nhead_lnum = le32_to_cpu(c->mst_node->nhead_lnum);
288 c->nhead_offs = le32_to_cpu(c->mst_node->nhead_offs);
289 c->ltab_lnum = le32_to_cpu(c->mst_node->ltab_lnum);
290 c->ltab_offs = le32_to_cpu(c->mst_node->ltab_offs);
291 c->lsave_lnum = le32_to_cpu(c->mst_node->lsave_lnum);
292 c->lsave_offs = le32_to_cpu(c->mst_node->lsave_offs);
293 c->lscan_lnum = le32_to_cpu(c->mst_node->lscan_lnum);
294 c->lst.empty_lebs = le32_to_cpu(c->mst_node->empty_lebs);
295 c->lst.idx_lebs = le32_to_cpu(c->mst_node->idx_lebs);
296 old_leb_cnt = le32_to_cpu(c->mst_node->leb_cnt);
297 c->lst.total_free = le64_to_cpu(c->mst_node->total_free);
298 c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty);
299 c->lst.total_used = le64_to_cpu(c->mst_node->total_used);
300 c->lst.total_dead = le64_to_cpu(c->mst_node->total_dead);
301 c->lst.total_dark = le64_to_cpu(c->mst_node->total_dark);
302
303 c->calc_idx_sz = c->bi.old_idx_sz;
304
305 if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
306 c->no_orphs = 1;
307
308 if (old_leb_cnt != c->leb_cnt) {
309 /* The file system has been resized */
310 int growth = c->leb_cnt - old_leb_cnt;
311
312 if (c->leb_cnt < old_leb_cnt ||
313 c->leb_cnt < UBIFS_MIN_LEB_CNT) {
314 ubifs_err(c, "bad leb_cnt on master node");
315 ubifs_dump_node(c, c->mst_node);
316 return -EINVAL;
317 }
318
319 dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs",
320 old_leb_cnt, c->leb_cnt);
321 c->lst.empty_lebs += growth;
322 c->lst.total_free += growth * (long long)c->leb_size;
323 c->lst.total_dark += growth * (long long)c->dark_wm;
324
325 /*
326 * Reflect changes back onto the master node. N.B. the master
327 * node gets written immediately whenever mounting (or
328 * remounting) in read-write mode, so we do not need to write it
329 * here.
330 */
331 c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt);
332 c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs);
333 c->mst_node->total_free = cpu_to_le64(c->lst.total_free);
334 c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark);
335 }
336
337 err = validate_master(c);
338 if (err)
339 return err;
340
341 #ifndef __UBOOT__
342 err = dbg_old_index_check_init(c, &c->zroot);
343 #endif
344
345 return err;
346 }
347
348 #ifndef __UBOOT__
349 /**
350 * ubifs_write_master - write master node.
351 * @c: UBIFS file-system description object
352 *
353 * This function writes the master node. Returns zero in case of success and a
354 * negative error code in case of failure. The master node is written twice to
355 * enable recovery.
356 */
ubifs_write_master(struct ubifs_info * c)357 int ubifs_write_master(struct ubifs_info *c)
358 {
359 int err, lnum, offs, len;
360
361 ubifs_assert(!c->ro_media && !c->ro_mount);
362 if (c->ro_error)
363 return -EROFS;
364
365 lnum = UBIFS_MST_LNUM;
366 offs = c->mst_offs + c->mst_node_alsz;
367 len = UBIFS_MST_NODE_SZ;
368
369 if (offs + UBIFS_MST_NODE_SZ > c->leb_size) {
370 err = ubifs_leb_unmap(c, lnum);
371 if (err)
372 return err;
373 offs = 0;
374 }
375
376 c->mst_offs = offs;
377 c->mst_node->highest_inum = cpu_to_le64(c->highest_inum);
378
379 err = ubifs_write_node(c, c->mst_node, len, lnum, offs);
380 if (err)
381 return err;
382
383 lnum += 1;
384
385 if (offs == 0) {
386 err = ubifs_leb_unmap(c, lnum);
387 if (err)
388 return err;
389 }
390 err = ubifs_write_node(c, c->mst_node, len, lnum, offs);
391
392 return err;
393 }
394 #endif
395