| 1 | |
| 2 | |
| 3 | * This file is part of UBIFS.
|
| 4 | *
|
| 5 | * Copyright (C) 2006-2008 Nokia Corporation.
|
| 6 | *
|
| 7 | * Authors: Adrian Hunter
|
| 8 | * Artem Bityutskiy (Битюцкий Артём)
|
| 9 |
|
| 10 |
|
| 11 | |
| 12 | * This file implements TNC (Tree Node Cache) which caches indexing nodes of
|
| 13 | * the UBIFS B-tree.
|
| 14 | *
|
| 15 | * At the moment the locking rules of the TNC tree are quite simple and
|
| 16 | * straightforward. We just have a mutex and lock it when we traverse the
|
| 17 | * tree. If a znode is not in memory, we read it from flash while still having
|
| 18 | * the mutex locked.
|
| 19 |
|
| 20 |
|
| 21 | #include <linux/crc32.h>
|
| 22 | #include <linux/slab.h>
|
| 23 | #include "ubifs.h"
|
| 24 |
|
| 25 | static int try_read_node(const struct ubifs_info *c, void *buf, int type,
|
| 26 | struct ubifs_zbranch *zbr);
|
| 27 | static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key,
|
| 28 | struct ubifs_zbranch *zbr, void *node);
|
| 29 |
|
| 30 | |
| 31 | * Returned codes of 'matches_name()' and 'fallible_matches_name()' functions.
|
| 32 | * @NAME_LESS: name corresponding to the first argument is less than second
|
| 33 | * @NAME_MATCHES: names match
|
| 34 | * @NAME_GREATER: name corresponding to the second argument is greater than
|
| 35 | * first
|
| 36 | * @NOT_ON_MEDIA: node referred by zbranch does not exist on the media
|
| 37 | *
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| 38 | * These constants were introduce to improve readability.
|
| 39 |
|
| 40 | enum {
|
| 41 | NAME_LESS = 0,
|
| 42 | NAME_MATCHES = 1,
|
| 43 | NAME_GREATER = 2,
|
| 44 | NOT_ON_MEDIA = 3,
|
| 45 | };
|
| 46 |
|
| 47 | static void do_insert_old_idx(struct ubifs_info *c,
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| 48 | struct ubifs_old_idx *old_idx)
|
| 49 | {
|
| 50 | struct ubifs_old_idx *o;
|
| 51 | struct rb_node **p, *parent = NULL;
|
| 52 |
|
| 53 | p = &c->old_idx.rb_node;
|
| 54 | while (*p) {
|
| 55 | parent = *p;
|
| 56 | o = rb_entry(parent, struct ubifs_old_idx, rb);
|
| 57 | if (old_idx->lnum < o->lnum)
|
| 58 | p = &(*p)->rb_left;
|
| 59 | else if (old_idx->lnum > o->lnum)
|
| 60 | p = &(*p)->rb_right;
|
| 61 | else if (old_idx->offs < o->offs)
|
| 62 | p = &(*p)->rb_left;
|
| 63 | else if (old_idx->offs > o->offs)
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| 64 | p = &(*p)->rb_right;
|
| 65 | else {
|
| 66 | ubifs_err(c, "old idx added twice!");
|
| 67 | kfree(old_idx);
|
| 68 | return;
|
| 69 | }
|
| 70 | }
|
| 71 | rb_link_node(&old_idx->rb, parent, p);
|
| 72 | rb_insert_color(&old_idx->rb, &c->old_idx);
|
| 73 | }
|
| 74 |
|
| 75 | |
| 76 | * insert_old_idx - record an index node obsoleted since the last commit start.
|
| 77 | * @c: UBIFS file-system description object
|
| 78 | * @lnum: LEB number of obsoleted index node
|
| 79 | * @offs: offset of obsoleted index node
|
| 80 | *
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| 81 | * Returns %0 on success, and a negative error code on failure.
|
| 82 | *
|
| 83 | * For recovery, there must always be a complete intact version of the index on
|
| 84 | * flash at all times. That is called the "old index". It is the index as at the
|
| 85 | * time of the last successful commit. Many of the index nodes in the old index
|
| 86 | * may be dirty, but they must not be erased until the next successful commit
|
| 87 | * (at which point that index becomes the old index).
|
| 88 | *
|
| 89 | * That means that the garbage collection and the in-the-gaps method of
|
| 90 | * committing must be able to determine if an index node is in the old index.
|
| 91 | * Most of the old index nodes can be found by looking up the TNC using the
|
| 92 | * 'lookup_znode()' function. However, some of the old index nodes may have
|
| 93 | * been deleted from the current index or may have been changed so much that
|
| 94 | * they cannot be easily found. In those cases, an entry is added to an RB-tree.
|
| 95 | * That is what this function does. The RB-tree is ordered by LEB number and
|
| 96 | * offset because they uniquely identify the old index node.
|
| 97 |
|
| 98 | static int insert_old_idx(struct ubifs_info *c, int lnum, int offs)
|
| 99 | {
|
| 100 | struct ubifs_old_idx *old_idx;
|
| 101 |
|
| 102 | old_idx = kmalloc_obj(struct ubifs_old_idx, GFP_NOFS);
|
| 103 | if (unlikely(!old_idx))
|
| 104 | return -ENOMEM;
|
| 105 | old_idx->lnum = lnum;
|
| 106 | old_idx->offs = offs;
|
| 107 | do_insert_old_idx(c, old_idx);
|
| 108 |
|
| 109 | return 0;
|
| 110 | }
|
| 111 |
|
| 112 | |
| 113 | * insert_old_idx_znode - record a znode obsoleted since last commit start.
|
| 114 | * @c: UBIFS file-system description object
|
| 115 | * @znode: znode of obsoleted index node
|
| 116 | *
|
| 117 | * Returns %0 on success, and a negative error code on failure.
|
| 118 |
|
| 119 | int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode)
|
| 120 | {
|
| 121 | if (znode->parent) {
|
| 122 | struct ubifs_zbranch *zbr;
|
| 123 |
|
| 124 | zbr = &znode->parent->zbranch[znode->iip];
|
| 125 | if (zbr->len)
|
| 126 | return insert_old_idx(c, zbr->lnum, zbr->offs);
|
| 127 | } else
|
| 128 | if (c->zroot.len)
|
| 129 | return insert_old_idx(c, c->zroot.lnum,
|
| 130 | c->zroot.offs);
|
| 131 | return 0;
|
| 132 | }
|
| 133 |
|
| 134 | |
| 135 | * ins_clr_old_idx_znode - record a znode obsoleted since last commit start.
|
| 136 | * @c: UBIFS file-system description object
|
| 137 | * @znode: znode of obsoleted index node
|
| 138 | *
|
| 139 | * Returns %0 on success, and a negative error code on failure.
|
| 140 |
|
| 141 | static int ins_clr_old_idx_znode(struct ubifs_info *c,
|
| 142 | struct ubifs_znode *znode)
|
| 143 | {
|
| 144 | int err;
|
| 145 |
|
| 146 | if (znode->parent) {
|
| 147 | struct ubifs_zbranch *zbr;
|
| 148 |
|
| 149 | zbr = &znode->parent->zbranch[znode->iip];
|
| 150 | if (zbr->len) {
|
| 151 | err = insert_old_idx(c, zbr->lnum, zbr->offs);
|
| 152 | if (err)
|
| 153 | return err;
|
| 154 | zbr->lnum = 0;
|
| 155 | zbr->offs = 0;
|
| 156 | zbr->len = 0;
|
| 157 | }
|
| 158 | } else
|
| 159 | if (c->zroot.len) {
|
| 160 | err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs);
|
| 161 | if (err)
|
| 162 | return err;
|
| 163 | c->zroot.lnum = 0;
|
| 164 | c->zroot.offs = 0;
|
| 165 | c->zroot.len = 0;
|
| 166 | }
|
| 167 | return 0;
|
| 168 | }
|
| 169 |
|
| 170 | |
| 171 | * destroy_old_idx - destroy the old_idx RB-tree.
|
| 172 | * @c: UBIFS file-system description object
|
| 173 | *
|
| 174 | * During start commit, the old_idx RB-tree is used to avoid overwriting index
|
| 175 | * nodes that were in the index last commit but have since been deleted. This
|
| 176 | * is necessary for recovery i.e. the old index must be kept intact until the
|
| 177 | * new index is successfully written. The old-idx RB-tree is used for the
|
| 178 | * in-the-gaps method of writing index nodes and is destroyed every commit.
|
| 179 |
|
| 180 | void destroy_old_idx(struct ubifs_info *c)
|
| 181 | {
|
| 182 | struct ubifs_old_idx *old_idx, *n;
|
| 183 |
|
| 184 | rbtree_postorder_for_each_entry_safe(old_idx, n, &c->old_idx, rb)
|
| 185 | kfree(old_idx);
|
| 186 |
|
| 187 | c->old_idx = RB_ROOT;
|
| 188 | }
|
| 189 |
|
| 190 | |
| 191 | * copy_znode - copy a dirty znode.
|
| 192 | * @c: UBIFS file-system description object
|
| 193 | * @znode: znode to copy
|
| 194 | *
|
| 195 | * A dirty znode being committed may not be changed, so it is copied.
|
| 196 |
|
| 197 | static struct ubifs_znode *copy_znode(struct ubifs_info *c,
|
| 198 | struct ubifs_znode *znode)
|
| 199 | {
|
| 200 | struct ubifs_znode *zn;
|
| 201 |
|
| 202 | zn = kmemdup(znode, c->max_znode_sz, GFP_NOFS);
|
| 203 | if (unlikely(!zn))
|
| 204 | return ERR_PTR(-ENOMEM);
|
| 205 |
|
| 206 | zn->cnext = NULL;
|
| 207 | __set_bit(DIRTY_ZNODE, &zn->flags);
|
| 208 | __clear_bit(COW_ZNODE, &zn->flags);
|
| 209 |
|
| 210 | return zn;
|
| 211 | }
|
| 212 |
|
| 213 | |
| 214 | * add_idx_dirt - add dirt due to a dirty znode.
|
| 215 | * @c: UBIFS file-system description object
|
| 216 | * @lnum: LEB number of index node
|
| 217 | * @dirt: size of index node
|
| 218 | *
|
| 219 | * This function updates lprops dirty space and the new size of the index.
|
| 220 |
|
| 221 | static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt)
|
| 222 | {
|
| 223 | c->calc_idx_sz -= ALIGN(dirt, 8);
|
| 224 | return ubifs_add_dirt(c, lnum, dirt);
|
| 225 | }
|
| 226 |
|
| 227 | |
| 228 | * replace_znode - replace old znode with new znode.
|
| 229 | * @c: UBIFS file-system description object
|
| 230 | * @new_zn: new znode
|
| 231 | * @old_zn: old znode
|
| 232 | * @zbr: the branch of parent znode
|
| 233 | *
|
| 234 | * Replace old znode with new znode in TNC.
|
| 235 |
|
| 236 | static void replace_znode(struct ubifs_info *c, struct ubifs_znode *new_zn,
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| 237 | struct ubifs_znode *old_zn, struct ubifs_zbranch *zbr)
|
| 238 | {
|
| 239 | ubifs_assert(c, !ubifs_zn_obsolete(old_zn));
|
| 240 | __set_bit(OBSOLETE_ZNODE, &old_zn->flags);
|
| 241 |
|
| 242 | if (old_zn->level != 0) {
|
| 243 | int i;
|
| 244 | const int n = new_zn->child_cnt;
|
| 245 |
|
| 246 |
|
| 247 | for (i = 0; i < n; i++) {
|
| 248 | struct ubifs_zbranch *child = &new_zn->zbranch[i];
|
| 249 |
|
| 250 | if (child->znode)
|
| 251 | child->znode->parent = new_zn;
|
| 252 | }
|
| 253 | }
|
| 254 |
|
| 255 | zbr->znode = new_zn;
|
| 256 | zbr->lnum = 0;
|
| 257 | zbr->offs = 0;
|
| 258 | zbr->len = 0;
|
| 259 |
|
| 260 | atomic_long_inc(&c->dirty_zn_cnt);
|
| 261 | }
|
| 262 |
|
| 263 | |
| 264 | * dirty_cow_znode - ensure a znode is not being committed.
|
| 265 | * @c: UBIFS file-system description object
|
| 266 | * @zbr: branch of znode to check
|
| 267 | *
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| 268 | * Returns dirtied znode on success or negative error code on failure.
|
| 269 |
|
| 270 | static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c,
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| 271 | struct ubifs_zbranch *zbr)
|
| 272 | {
|
| 273 | struct ubifs_znode *znode = zbr->znode;
|
| 274 | struct ubifs_znode *zn;
|
| 275 | int err;
|
| 276 |
|
| 277 | if (!ubifs_zn_cow(znode)) {
|
| 278 |
|
| 279 | if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) {
|
| 280 | atomic_long_inc(&c->dirty_zn_cnt);
|
| 281 | atomic_long_dec(&c->clean_zn_cnt);
|
| 282 | atomic_long_dec(&ubifs_clean_zn_cnt);
|
| 283 | err = add_idx_dirt(c, zbr->lnum, zbr->len);
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| 284 | if (unlikely(err))
|
| 285 | return ERR_PTR(err);
|
| 286 | }
|
| 287 | return znode;
|
| 288 | }
|
| 289 |
|
| 290 | zn = copy_znode(c, znode);
|
| 291 | if (IS_ERR(zn))
|
| 292 | return zn;
|
| 293 |
|
| 294 | if (zbr->len) {
|
| 295 | struct ubifs_old_idx *old_idx;
|
| 296 |
|
| 297 | old_idx = kmalloc_obj(struct ubifs_old_idx, GFP_NOFS);
|
| 298 | if (unlikely(!old_idx)) {
|
| 299 | err = -ENOMEM;
|
| 300 | goto out;
|
| 301 | }
|
| 302 | old_idx->lnum = zbr->lnum;
|
| 303 | old_idx->offs = zbr->offs;
|
| 304 |
|
| 305 | err = add_idx_dirt(c, zbr->lnum, zbr->len);
|
| 306 | if (err) {
|
| 307 | kfree(old_idx);
|
| 308 | goto out;
|
| 309 | }
|
| 310 |
|
| 311 | do_insert_old_idx(c, old_idx);
|
| 312 | }
|
| 313 |
|
| 314 | replace_znode(c, zn, znode, zbr);
|
| 315 |
|
| 316 | return zn;
|
| 317 |
|
| 318 | out:
|
| 319 | kfree(zn);
|
| 320 | return ERR_PTR(err);
|
| 321 | }
|
| 322 |
|
| 323 | |
| 324 | * lnc_add - add a leaf node to the leaf node cache.
|
| 325 | * @c: UBIFS file-system description object
|
| 326 | * @zbr: zbranch of leaf node
|
| 327 | * @node: leaf node
|
| 328 | *
|
| 329 | * Leaf nodes are non-index nodes directory entry nodes or data nodes. The
|
| 330 | * purpose of the leaf node cache is to save re-reading the same leaf node over
|
| 331 | * and over again. Most things are cached by VFS, however the file system must
|
| 332 | * cache directory entries for readdir and for resolving hash collisions. The
|
| 333 | * present implementation of the leaf node cache is extremely simple, and
|
| 334 | * allows for error returns that are not used but that may be needed if a more
|
| 335 | * complex implementation is created.
|
| 336 | *
|
| 337 | * Note, this function does not add the @node object to LNC directly, but
|
| 338 | * allocates a copy of the object and adds the copy to LNC. The reason for this
|
| 339 | * is that @node has been allocated outside of the TNC subsystem and will be
|
| 340 | * used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC
|
| 341 | * may be changed at any time, e.g. freed by the shrinker.
|
| 342 |
|
| 343 | static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr,
|
| 344 | const void *node)
|
| 345 | {
|
| 346 | int err;
|
| 347 | void *lnc_node;
|
| 348 | const struct ubifs_dent_node *dent = node;
|
| 349 |
|
| 350 | ubifs_assert(c, !zbr->leaf);
|
| 351 | ubifs_assert(c, zbr->len != 0);
|
| 352 | ubifs_assert(c, is_hash_key(c, &zbr->key));
|
| 353 |
|
| 354 | err = ubifs_validate_entry(c, dent);
|
| 355 | if (err) {
|
| 356 | dump_stack();
|
| 357 | ubifs_dump_node(c, dent, zbr->len);
|
| 358 | return err;
|
| 359 | }
|
| 360 |
|
| 361 | lnc_node = kmemdup(node, zbr->len, GFP_NOFS);
|
| 362 | if (!lnc_node)
|
| 363 |
|
| 364 | return 0;
|
| 365 |
|
| 366 | zbr->leaf = lnc_node;
|
| 367 | return 0;
|
| 368 | }
|
| 369 |
|
| 370 | |
| 371 | * lnc_add_directly - add a leaf node to the leaf-node-cache.
|
| 372 | * @c: UBIFS file-system description object
|
| 373 | * @zbr: zbranch of leaf node
|
| 374 | * @node: leaf node
|
| 375 | *
|
| 376 | * This function is similar to 'lnc_add()', but it does not create a copy of
|
| 377 | * @node but inserts @node to TNC directly.
|
| 378 |
|
| 379 | static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr,
|
| 380 | void *node)
|
| 381 | {
|
| 382 | int err;
|
| 383 |
|
| 384 | ubifs_assert(c, !zbr->leaf);
|
| 385 | ubifs_assert(c, zbr->len != 0);
|
| 386 |
|
| 387 | err = ubifs_validate_entry(c, node);
|
| 388 | if (err) {
|
| 389 | dump_stack();
|
| 390 | ubifs_dump_node(c, node, zbr->len);
|
| 391 | return err;
|
| 392 | }
|
| 393 |
|
| 394 | zbr->leaf = node;
|
| 395 | return 0;
|
| 396 | }
|
| 397 |
|
| 398 | |
| 399 | * lnc_free - remove a leaf node from the leaf node cache.
|
| 400 | * @zbr: zbranch of leaf node
|
| 401 |
|
| 402 | static void lnc_free(struct ubifs_zbranch *zbr)
|
| 403 | {
|
| 404 | if (!zbr->leaf)
|
| 405 | return;
|
| 406 | kfree(zbr->leaf);
|
| 407 | zbr->leaf = NULL;
|
| 408 | }
|
| 409 |
|
| 410 | |
| 411 | * tnc_read_hashed_node - read a "hashed" leaf node.
|
| 412 | * @c: UBIFS file-system description object
|
| 413 | * @zbr: key and position of the node
|
| 414 | * @node: node is returned here
|
| 415 | *
|
| 416 | * This function reads a "hashed" node defined by @zbr from the leaf node cache
|
| 417 | * (in it is there) or from the hash media, in which case the node is also
|
| 418 | * added to LNC. Returns zero in case of success or a negative error
|
| 419 | * code in case of failure.
|
| 420 |
|
| 421 | static int tnc_read_hashed_node(struct ubifs_info *c, struct ubifs_zbranch *zbr,
|
| 422 | void *node)
|
| 423 | {
|
| 424 | int err;
|
| 425 |
|
| 426 | ubifs_assert(c, is_hash_key(c, &zbr->key));
|
| 427 |
|
| 428 | if (zbr->leaf) {
|
| 429 |
|
| 430 | ubifs_assert(c, zbr->len != 0);
|
| 431 | memcpy(node, zbr->leaf, zbr->len);
|
| 432 | return 0;
|
| 433 | }
|
| 434 |
|
| 435 | if (c->replaying) {
|
| 436 | err = fallible_read_node(c, &zbr->key, zbr, node);
|
| 437 | |
| 438 | * When the node was not found, return -ENOENT, 0 otherwise.
|
| 439 | * Negative return codes stay as-is.
|
| 440 |
|
| 441 | if (err == 0)
|
| 442 | err = -ENOENT;
|
| 443 | else if (err == 1)
|
| 444 | err = 0;
|
| 445 | } else {
|
| 446 | err = ubifs_tnc_read_node(c, zbr, node);
|
| 447 | }
|
| 448 | if (err)
|
| 449 | return err;
|
| 450 |
|
| 451 |
|
| 452 | err = lnc_add(c, zbr, node);
|
| 453 | return err;
|
| 454 | }
|
| 455 |
|
| 456 | |
| 457 | * try_read_node - read a node if it is a node.
|
| 458 | * @c: UBIFS file-system description object
|
| 459 | * @buf: buffer to read to
|
| 460 | * @type: node type
|
| 461 | * @zbr: the zbranch describing the node to read
|
| 462 | *
|
| 463 | * This function tries to read a node of known type and length, checks it and
|
| 464 | * stores it in @buf. This function returns %1 if a node is present and %0 if
|
| 465 | * a node is not present. A negative error code is returned for I/O errors.
|
| 466 | * This function performs that same function as ubifs_read_node except that
|
| 467 | * it does not require that there is actually a node present and instead
|
| 468 | * the return code indicates if a node was read.
|
| 469 | *
|
| 470 | * Note, this function does not check CRC of data nodes if @c->no_chk_data_crc
|
| 471 | * is true (it is controlled by corresponding mount option). However, if
|
| 472 | * @c->mounting or @c->remounting_rw is true (we are mounting or re-mounting to
|
| 473 | * R/W mode), @c->no_chk_data_crc is ignored and CRC is checked. This is
|
| 474 | * because during mounting or re-mounting from R/O mode to R/W mode we may read
|
| 475 | * journal nodes (when replying the journal or doing the recovery) and the
|
| 476 | * journal nodes may potentially be corrupted, so checking is required.
|
| 477 |
|
| 478 | static int try_read_node(const struct ubifs_info *c, void *buf, int type,
|
| 479 | struct ubifs_zbranch *zbr)
|
| 480 | {
|
| 481 | int len = zbr->len;
|
| 482 | int lnum = zbr->lnum;
|
| 483 | int offs = zbr->offs;
|
| 484 | int err, node_len;
|
| 485 | struct ubifs_ch *ch = buf;
|
| 486 | uint32_t crc, node_crc;
|
| 487 |
|
| 488 | dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
|
| 489 |
|
| 490 | err = ubifs_leb_read(c, lnum, buf, offs, len, 1);
|
| 491 | if (err) {
|
| 492 | ubifs_err(c, "cannot read node type %d from LEB %d:%d, error %d",
|
| 493 | type, lnum, offs, err);
|
| 494 | return err;
|
| 495 | }
|
| 496 |
|
| 497 | if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC)
|
| 498 | return 0;
|
| 499 |
|
| 500 | if (ch->node_type != type)
|
| 501 | return 0;
|
| 502 |
|
| 503 | node_len = le32_to_cpu(ch->len);
|
| 504 | if (node_len != len)
|
| 505 | return 0;
|
| 506 |
|
| 507 | if (type != UBIFS_DATA_NODE || !c->no_chk_data_crc || c->mounting ||
|
| 508 | c->remounting_rw) {
|
| 509 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
|
| 510 | node_crc = le32_to_cpu(ch->crc);
|
| 511 | if (crc != node_crc)
|
| 512 | return 0;
|
| 513 | }
|
| 514 |
|
| 515 | err = ubifs_node_check_hash(c, buf, zbr->hash);
|
| 516 | if (err) {
|
| 517 | ubifs_bad_hash(c, buf, zbr->hash, lnum, offs);
|
| 518 | return 0;
|
| 519 | }
|
| 520 |
|
| 521 | return 1;
|
| 522 | }
|
| 523 |
|
| 524 | |
| 525 | * fallible_read_node - try to read a leaf node.
|
| 526 | * @c: UBIFS file-system description object
|
| 527 | * @key: key of node to read
|
| 528 | * @zbr: position of node
|
| 529 | * @node: node returned
|
| 530 | *
|
| 531 | * This function tries to read a node and returns %1 if the node is read, %0
|
| 532 | * if the node is not present, and a negative error code in the case of error.
|
| 533 |
|
| 534 | static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key,
|
| 535 | struct ubifs_zbranch *zbr, void *node)
|
| 536 | {
|
| 537 | int ret;
|
| 538 |
|
| 539 | dbg_tnck(key, "LEB %d:%d, key ", zbr->lnum, zbr->offs);
|
| 540 |
|
| 541 | ret = try_read_node(c, node, key_type(c, key), zbr);
|
| 542 | if (ret == 1) {
|
| 543 | union ubifs_key node_key;
|
| 544 | struct ubifs_dent_node *dent = node;
|
| 545 |
|
| 546 |
|
| 547 | key_read(c, &dent->key, &node_key);
|
| 548 | if (keys_cmp(c, key, &node_key) != 0)
|
| 549 | ret = 0;
|
| 550 | }
|
| 551 | if (ret == 0 && c->replaying)
|
| 552 | dbg_mntk(key, "dangling branch LEB %d:%d len %d, key ",
|
| 553 | zbr->lnum, zbr->offs, zbr->len);
|
| 554 | return ret;
|
| 555 | }
|
| 556 |
|
| 557 | |
| 558 | * matches_name - determine if a direntry or xattr entry matches a given name.
|
| 559 | * @c: UBIFS file-system description object
|
| 560 | * @zbr: zbranch of dent
|
| 561 | * @nm: name to match
|
| 562 | *
|
| 563 | * This function checks if xentry/direntry referred by zbranch @zbr matches name
|
| 564 | * @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by
|
| 565 | * @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case
|
| 566 | * of failure, a negative error code is returned.
|
| 567 |
|
| 568 | static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr,
|
| 569 | const struct fscrypt_name *nm)
|
| 570 | {
|
| 571 | struct ubifs_dent_node *dent;
|
| 572 | int nlen, err;
|
| 573 |
|
| 574 |
|
| 575 | if (!zbr->leaf) {
|
| 576 | dent = kmalloc(zbr->len, GFP_NOFS);
|
| 577 | if (!dent)
|
| 578 | return -ENOMEM;
|
| 579 |
|
| 580 | err = ubifs_tnc_read_node(c, zbr, dent);
|
| 581 | if (err)
|
| 582 | goto out_free;
|
| 583 |
|
| 584 |
|
| 585 | err = lnc_add_directly(c, zbr, dent);
|
| 586 | if (err)
|
| 587 | goto out_free;
|
| 588 | } else
|
| 589 | dent = zbr->leaf;
|
| 590 |
|
| 591 | nlen = le16_to_cpu(dent->nlen);
|
| 592 | err = memcmp(dent->name, fname_name(nm), min_t(int, nlen, fname_len(nm)));
|
| 593 | if (err == 0) {
|
| 594 | if (nlen == fname_len(nm))
|
| 595 | return NAME_MATCHES;
|
| 596 | else if (nlen < fname_len(nm))
|
| 597 | return NAME_LESS;
|
| 598 | else
|
| 599 | return NAME_GREATER;
|
| 600 | } else if (err < 0)
|
| 601 | return NAME_LESS;
|
| 602 | else
|
| 603 | return NAME_GREATER;
|
| 604 |
|
| 605 | out_free:
|
| 606 | kfree(dent);
|
| 607 | return err;
|
| 608 | }
|
| 609 |
|
| 610 | |
| 611 | * get_znode - get a TNC znode that may not be loaded yet.
|
| 612 | * @c: UBIFS file-system description object
|
| 613 | * @znode: parent znode
|
| 614 | * @n: znode branch slot number
|
| 615 | *
|
| 616 | * This function returns the znode or a negative error code.
|
| 617 |
|
| 618 | static struct ubifs_znode *get_znode(struct ubifs_info *c,
|
| 619 | struct ubifs_znode *znode, int n)
|
| 620 | {
|
| 621 | struct ubifs_zbranch *zbr;
|
| 622 |
|
| 623 | zbr = &znode->zbranch[n];
|
| 624 | if (zbr->znode)
|
| 625 | znode = zbr->znode;
|
| 626 | else
|
| 627 | znode = ubifs_load_znode(c, zbr, znode, n);
|
| 628 | return znode;
|
| 629 | }
|
| 630 |
|
| 631 | |
| 632 | * tnc_next - find next TNC entry.
|
| 633 | * @c: UBIFS file-system description object
|
| 634 | * @zn: znode is passed and returned here
|
| 635 | * @n: znode branch slot number is passed and returned here
|
| 636 | *
|
| 637 | * This function returns %0 if the next TNC entry is found, %-ENOENT if there is
|
| 638 | * no next entry, or a negative error code otherwise.
|
| 639 |
|
| 640 | static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n)
|
| 641 | {
|
| 642 | struct ubifs_znode *znode = *zn;
|
| 643 | int nn = *n;
|
| 644 |
|
| 645 | nn += 1;
|
| 646 | if (nn < znode->child_cnt) {
|
| 647 | *n = nn;
|
| 648 | return 0;
|
| 649 | }
|
| 650 | while (1) {
|
| 651 | struct ubifs_znode *zp;
|
| 652 |
|
| 653 | zp = znode->parent;
|
| 654 | if (!zp)
|
| 655 | return -ENOENT;
|
| 656 | nn = znode->iip + 1;
|
| 657 | znode = zp;
|
| 658 | if (nn < znode->child_cnt) {
|
| 659 | znode = get_znode(c, znode, nn);
|
| 660 | if (IS_ERR(znode))
|
| 661 | return PTR_ERR(znode);
|
| 662 | while (znode->level != 0) {
|
| 663 | znode = get_znode(c, znode, 0);
|
| 664 | if (IS_ERR(znode))
|
| 665 | return PTR_ERR(znode);
|
| 666 | }
|
| 667 | nn = 0;
|
| 668 | break;
|
| 669 | }
|
| 670 | }
|
| 671 | *zn = znode;
|
| 672 | *n = nn;
|
| 673 | return 0;
|
| 674 | }
|
| 675 |
|
| 676 | |
| 677 | * tnc_prev - find previous TNC entry.
|
| 678 | * @c: UBIFS file-system description object
|
| 679 | * @zn: znode is returned here
|
| 680 | * @n: znode branch slot number is passed and returned here
|
| 681 | *
|
| 682 | * This function returns %0 if the previous TNC entry is found, %-ENOENT if
|
| 683 | * there is no next entry, or a negative error code otherwise.
|
| 684 |
|
| 685 | static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n)
|
| 686 | {
|
| 687 | struct ubifs_znode *znode = *zn;
|
| 688 | int nn = *n;
|
| 689 |
|
| 690 | if (nn > 0) {
|
| 691 | *n = nn - 1;
|
| 692 | return 0;
|
| 693 | }
|
| 694 | while (1) {
|
| 695 | struct ubifs_znode *zp;
|
| 696 |
|
| 697 | zp = znode->parent;
|
| 698 | if (!zp)
|
| 699 | return -ENOENT;
|
| 700 | nn = znode->iip - 1;
|
| 701 | znode = zp;
|
| 702 | if (nn >= 0) {
|
| 703 | znode = get_znode(c, znode, nn);
|
| 704 | if (IS_ERR(znode))
|
| 705 | return PTR_ERR(znode);
|
| 706 | while (znode->level != 0) {
|
| 707 | nn = znode->child_cnt - 1;
|
| 708 | znode = get_znode(c, znode, nn);
|
| 709 | if (IS_ERR(znode))
|
| 710 | return PTR_ERR(znode);
|
| 711 | }
|
| 712 | nn = znode->child_cnt - 1;
|
| 713 | break;
|
| 714 | }
|
| 715 | }
|
| 716 | *zn = znode;
|
| 717 | *n = nn;
|
| 718 | return 0;
|
| 719 | }
|
| 720 |
|
| 721 | |
| 722 | * resolve_collision - resolve a collision.
|
| 723 | * @c: UBIFS file-system description object
|
| 724 | * @key: key of a directory or extended attribute entry
|
| 725 | * @zn: znode is returned here
|
| 726 | * @n: zbranch number is passed and returned here
|
| 727 | * @nm: name of the entry
|
| 728 | *
|
| 729 | * This function is called for "hashed" keys to make sure that the found key
|
| 730 | * really corresponds to the looked up node (directory or extended attribute
|
| 731 | * entry). It returns %1 and sets @zn and @n if the collision is resolved.
|
| 732 | * %0 is returned if @nm is not found and @zn and @n are set to the previous
|
| 733 | * entry, i.e. to the entry after which @nm could follow if it were in TNC.
|
| 734 | * This means that @n may be set to %-1 if the leftmost key in @zn is the
|
| 735 | * previous one. A negative error code is returned on failures.
|
| 736 |
|
| 737 | static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key,
|
| 738 | struct ubifs_znode **zn, int *n,
|
| 739 | const struct fscrypt_name *nm)
|
| 740 | {
|
| 741 | int err;
|
| 742 |
|
| 743 | err = matches_name(c, &(*zn)->zbranch[*n], nm);
|
| 744 | if (unlikely(err < 0))
|
| 745 | return err;
|
| 746 | if (err == NAME_MATCHES)
|
| 747 | return 1;
|
| 748 |
|
| 749 | if (err == NAME_GREATER) {
|
| 750 |
|
| 751 | while (1) {
|
| 752 | err = tnc_prev(c, zn, n);
|
| 753 | if (err == -ENOENT) {
|
| 754 | ubifs_assert(c, *n == 0);
|
| 755 | *n = -1;
|
| 756 | return 0;
|
| 757 | }
|
| 758 | if (err < 0)
|
| 759 | return err;
|
| 760 | if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) {
|
| 761 | |
| 762 | * We have found the branch after which we would
|
| 763 | * like to insert, but inserting in this znode
|
| 764 | * may still be wrong. Consider the following 3
|
| 765 | * znodes, in the case where we are resolving a
|
| 766 | * collision with Key2.
|
| 767 | *
|
| 768 | * znode zp
|
| 769 | * ----------------------
|
| 770 | * level 1 | Key0 | Key1 |
|
| 771 | * -----------------------
|
| 772 | * | |
|
| 773 | * znode za | | znode zb
|
| 774 | * ------------ ------------
|
| 775 | * level 0 | Key0 | | Key2 |
|
| 776 | * ------------ ------------
|
| 777 | *
|
| 778 | * The lookup finds Key2 in znode zb. Lets say
|
| 779 | * there is no match and the name is greater so
|
| 780 | * we look left. When we find Key0, we end up
|
| 781 | * here. If we return now, we will insert into
|
| 782 | * znode za at slot n = 1. But that is invalid
|
| 783 | * according to the parent's keys. Key2 must
|
| 784 | * be inserted into znode zb.
|
| 785 | *
|
| 786 | * Note, this problem is not relevant for the
|
| 787 | * case when we go right, because
|
| 788 | * 'tnc_insert()' would correct the parent key.
|
| 789 |
|
| 790 | if (*n == (*zn)->child_cnt - 1) {
|
| 791 | err = tnc_next(c, zn, n);
|
| 792 | if (err) {
|
| 793 |
|
| 794 | ubifs_assert(c, 0);
|
| 795 | if (err == -ENOENT)
|
| 796 | err = -EINVAL;
|
| 797 | return err;
|
| 798 | }
|
| 799 | ubifs_assert(c, *n == 0);
|
| 800 | *n = -1;
|
| 801 | }
|
| 802 | return 0;
|
| 803 | }
|
| 804 | err = matches_name(c, &(*zn)->zbranch[*n], nm);
|
| 805 | if (err < 0)
|
| 806 | return err;
|
| 807 | if (err == NAME_LESS)
|
| 808 | return 0;
|
| 809 | if (err == NAME_MATCHES)
|
| 810 | return 1;
|
| 811 | ubifs_assert(c, err == NAME_GREATER);
|
| 812 | }
|
| 813 | } else {
|
| 814 | int nn = *n;
|
| 815 | struct ubifs_znode *znode = *zn;
|
| 816 |
|
| 817 |
|
| 818 | while (1) {
|
| 819 | err = tnc_next(c, &znode, &nn);
|
| 820 | if (err == -ENOENT)
|
| 821 | return 0;
|
| 822 | if (err < 0)
|
| 823 | return err;
|
| 824 | if (keys_cmp(c, &znode->zbranch[nn].key, key))
|
| 825 | return 0;
|
| 826 | err = matches_name(c, &znode->zbranch[nn], nm);
|
| 827 | if (err < 0)
|
| 828 | return err;
|
| 829 | if (err == NAME_GREATER)
|
| 830 | return 0;
|
| 831 | *zn = znode;
|
| 832 | *n = nn;
|
| 833 | if (err == NAME_MATCHES)
|
| 834 | return 1;
|
| 835 | ubifs_assert(c, err == NAME_LESS);
|
| 836 | }
|
| 837 | }
|
| 838 | }
|
| 839 |
|
| 840 | |
| 841 | * fallible_matches_name - determine if a dent matches a given name.
|
| 842 | * @c: UBIFS file-system description object
|
| 843 | * @zbr: zbranch of dent
|
| 844 | * @nm: name to match
|
| 845 | *
|
| 846 | * This is a "fallible" version of 'matches_name()' function which does not
|
| 847 | * panic if the direntry/xentry referred by @zbr does not exist on the media.
|
| 848 | *
|
| 849 | * This function checks if xentry/direntry referred by zbranch @zbr matches name
|
| 850 | * @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr
|
| 851 | * is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA
|
| 852 | * if xentry/direntry referred by @zbr does not exist on the media. A negative
|
| 853 | * error code is returned in case of failure.
|
| 854 |
|
| 855 | static int fallible_matches_name(struct ubifs_info *c,
|
| 856 | struct ubifs_zbranch *zbr,
|
| 857 | const struct fscrypt_name *nm)
|
| 858 | {
|
| 859 | struct ubifs_dent_node *dent;
|
| 860 | int nlen, err;
|
| 861 |
|
| 862 |
|
| 863 | if (!zbr->leaf) {
|
| 864 | dent = kmalloc(zbr->len, GFP_NOFS);
|
| 865 | if (!dent)
|
| 866 | return -ENOMEM;
|
| 867 |
|
| 868 | err = fallible_read_node(c, &zbr->key, zbr, dent);
|
| 869 | if (err < 0)
|
| 870 | goto out_free;
|
| 871 | if (err == 0) {
|
| 872 |
|
| 873 | err = NOT_ON_MEDIA;
|
| 874 | goto out_free;
|
| 875 | }
|
| 876 | ubifs_assert(c, err == 1);
|
| 877 |
|
| 878 | err = lnc_add_directly(c, zbr, dent);
|
| 879 | if (err)
|
| 880 | goto out_free;
|
| 881 | } else
|
| 882 | dent = zbr->leaf;
|
| 883 |
|
| 884 | nlen = le16_to_cpu(dent->nlen);
|
| 885 | err = memcmp(dent->name, fname_name(nm), min_t(int, nlen, fname_len(nm)));
|
| 886 | if (err == 0) {
|
| 887 | if (nlen == fname_len(nm))
|
| 888 | return NAME_MATCHES;
|
| 889 | else if (nlen < fname_len(nm))
|
| 890 | return NAME_LESS;
|
| 891 | else
|
| 892 | return NAME_GREATER;
|
| 893 | } else if (err < 0)
|
| 894 | return NAME_LESS;
|
| 895 | else
|
| 896 | return NAME_GREATER;
|
| 897 |
|
| 898 | out_free:
|
| 899 | kfree(dent);
|
| 900 | return err;
|
| 901 | }
|
| 902 |
|
| 903 | |
| 904 | * fallible_resolve_collision - resolve a collision even if nodes are missing.
|
| 905 | * @c: UBIFS file-system description object
|
| 906 | * @key: key
|
| 907 | * @zn: znode is returned here
|
| 908 | * @n: branch number is passed and returned here
|
| 909 | * @nm: name of directory entry
|
| 910 | * @adding: indicates caller is adding a key to the TNC
|
| 911 | *
|
| 912 | * This is a "fallible" version of the 'resolve_collision()' function which
|
| 913 | * does not panic if one of the nodes referred to by TNC does not exist on the
|
| 914 | * media. This may happen when replaying the journal if a deleted node was
|
| 915 | * Garbage-collected and the commit was not done. A branch that refers to a node
|
| 916 | * that is not present is called a dangling branch. The following are the return
|
| 917 | * codes for this function:
|
| 918 | * o if @nm was found, %1 is returned and @zn and @n are set to the found
|
| 919 | * branch;
|
| 920 | * o if we are @adding and @nm was not found, %0 is returned;
|
| 921 | * o if we are not @adding and @nm was not found, but a dangling branch was
|
| 922 | * found, then %1 is returned and @zn and @n are set to the dangling branch;
|
| 923 | * o a negative error code is returned in case of failure.
|
| 924 |
|
| 925 | static int fallible_resolve_collision(struct ubifs_info *c,
|
| 926 | const union ubifs_key *key,
|
| 927 | struct ubifs_znode **zn, int *n,
|
| 928 | const struct fscrypt_name *nm,
|
| 929 | int adding)
|
| 930 | {
|
| 931 | struct ubifs_znode *o_znode = NULL, *znode = *zn;
|
| 932 | int o_n, err, cmp, unsure = 0, nn = *n;
|
| 933 |
|
| 934 | cmp = fallible_matches_name(c, &znode->zbranch[nn], nm);
|
| 935 | if (unlikely(cmp < 0))
|
| 936 | return cmp;
|
| 937 | if (cmp == NAME_MATCHES)
|
| 938 | return 1;
|
| 939 | if (cmp == NOT_ON_MEDIA) {
|
| 940 | o_znode = znode;
|
| 941 | o_n = nn;
|
| 942 | |
| 943 | * We are unlucky and hit a dangling branch straight away.
|
| 944 | * Now we do not really know where to go to find the needed
|
| 945 | * branch - to the left or to the right. Well, let's try left.
|
| 946 |
|
| 947 | unsure = 1;
|
| 948 | } else if (!adding)
|
| 949 | unsure = 1;
|
| 950 |
|
| 951 | if (cmp == NAME_GREATER || unsure) {
|
| 952 |
|
| 953 | while (1) {
|
| 954 | err = tnc_prev(c, zn, n);
|
| 955 | if (err == -ENOENT) {
|
| 956 | ubifs_assert(c, *n == 0);
|
| 957 | *n = -1;
|
| 958 | break;
|
| 959 | }
|
| 960 | if (err < 0)
|
| 961 | return err;
|
| 962 | if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) {
|
| 963 |
|
| 964 | if (*n == (*zn)->child_cnt - 1) {
|
| 965 | err = tnc_next(c, zn, n);
|
| 966 | if (err) {
|
| 967 |
|
| 968 | ubifs_assert(c, 0);
|
| 969 | if (err == -ENOENT)
|
| 970 | err = -EINVAL;
|
| 971 | return err;
|
| 972 | }
|
| 973 | ubifs_assert(c, *n == 0);
|
| 974 | *n = -1;
|
| 975 | }
|
| 976 | break;
|
| 977 | }
|
| 978 | err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm);
|
| 979 | if (err < 0)
|
| 980 | return err;
|
| 981 | if (err == NAME_MATCHES)
|
| 982 | return 1;
|
| 983 | if (err == NOT_ON_MEDIA) {
|
| 984 | o_znode = *zn;
|
| 985 | o_n = *n;
|
| 986 | continue;
|
| 987 | }
|
| 988 | if (!adding)
|
| 989 | continue;
|
| 990 | if (err == NAME_LESS)
|
| 991 | break;
|
| 992 | else
|
| 993 | unsure = 0;
|
| 994 | }
|
| 995 | }
|
| 996 |
|
| 997 | if (cmp == NAME_LESS || unsure) {
|
| 998 |
|
| 999 | *zn = znode;
|
| 1000 | *n = nn;
|
| 1001 | while (1) {
|
| 1002 | err = tnc_next(c, &znode, &nn);
|
| 1003 | if (err == -ENOENT)
|
| 1004 | break;
|
| 1005 | if (err < 0)
|
| 1006 | return err;
|
| 1007 | if (keys_cmp(c, &znode->zbranch[nn].key, key))
|
| 1008 | break;
|
| 1009 | err = fallible_matches_name(c, &znode->zbranch[nn], nm);
|
| 1010 | if (err < 0)
|
| 1011 | return err;
|
| 1012 | if (err == NAME_GREATER)
|
| 1013 | break;
|
| 1014 | *zn = znode;
|
| 1015 | *n = nn;
|
| 1016 | if (err == NAME_MATCHES)
|
| 1017 | return 1;
|
| 1018 | if (err == NOT_ON_MEDIA) {
|
| 1019 | o_znode = znode;
|
| 1020 | o_n = nn;
|
| 1021 | }
|
| 1022 | }
|
| 1023 | }
|
| 1024 |
|
| 1025 |
|
| 1026 | if (adding || !o_znode)
|
| 1027 | return 0;
|
| 1028 |
|
| 1029 | dbg_mntk(key, "dangling match LEB %d:%d len %d key ",
|
| 1030 | o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs,
|
| 1031 | o_znode->zbranch[o_n].len);
|
| 1032 | *zn = o_znode;
|
| 1033 | *n = o_n;
|
| 1034 | return 1;
|
| 1035 | }
|
| 1036 |
|
| 1037 | |
| 1038 | * matches_position - determine if a zbranch matches a given position.
|
| 1039 | * @zbr: zbranch of dent
|
| 1040 | * @lnum: LEB number of dent to match
|
| 1041 | * @offs: offset of dent to match
|
| 1042 | *
|
| 1043 | * This function returns %1 if @lnum:@offs matches, and %0 otherwise.
|
| 1044 |
|
| 1045 | static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs)
|
| 1046 | {
|
| 1047 | if (zbr->lnum == lnum && zbr->offs == offs)
|
| 1048 | return 1;
|
| 1049 | else
|
| 1050 | return 0;
|
| 1051 | }
|
| 1052 |
|
| 1053 | |
| 1054 | * resolve_collision_directly - resolve a collision directly.
|
| 1055 | * @c: UBIFS file-system description object
|
| 1056 | * @key: key of directory entry
|
| 1057 | * @zn: znode is passed and returned here
|
| 1058 | * @n: zbranch number is passed and returned here
|
| 1059 | * @lnum: LEB number of dent node to match
|
| 1060 | * @offs: offset of dent node to match
|
| 1061 | *
|
| 1062 | * This function is used for "hashed" keys to make sure the found directory or
|
| 1063 | * extended attribute entry node is what was looked for. It is used when the
|
| 1064 | * flash address of the right node is known (@lnum:@offs) which makes it much
|
| 1065 | * easier to resolve collisions (no need to read entries and match full
|
| 1066 | * names). This function returns %1 and sets @zn and @n if the collision is
|
| 1067 | * resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the
|
| 1068 | * previous directory entry. Otherwise a negative error code is returned.
|
| 1069 |
|
| 1070 | static int resolve_collision_directly(struct ubifs_info *c,
|
| 1071 | const union ubifs_key *key,
|
| 1072 | struct ubifs_znode **zn, int *n,
|
| 1073 | int lnum, int offs)
|
| 1074 | {
|
| 1075 | struct ubifs_znode *znode;
|
| 1076 | int nn, err;
|
| 1077 |
|
| 1078 | znode = *zn;
|
| 1079 | nn = *n;
|
| 1080 | if (matches_position(&znode->zbranch[nn], lnum, offs))
|
| 1081 | return 1;
|
| 1082 |
|
| 1083 |
|
| 1084 | while (1) {
|
| 1085 | err = tnc_prev(c, &znode, &nn);
|
| 1086 | if (err == -ENOENT)
|
| 1087 | break;
|
| 1088 | if (err < 0)
|
| 1089 | return err;
|
| 1090 | if (keys_cmp(c, &znode->zbranch[nn].key, key))
|
| 1091 | break;
|
| 1092 | if (matches_position(&znode->zbranch[nn], lnum, offs)) {
|
| 1093 | *zn = znode;
|
| 1094 | *n = nn;
|
| 1095 | return 1;
|
| 1096 | }
|
| 1097 | }
|
| 1098 |
|
| 1099 |
|
| 1100 | znode = *zn;
|
| 1101 | nn = *n;
|
| 1102 | while (1) {
|
| 1103 | err = tnc_next(c, &znode, &nn);
|
| 1104 | if (err == -ENOENT)
|
| 1105 | return 0;
|
| 1106 | if (err < 0)
|
| 1107 | return err;
|
| 1108 | if (keys_cmp(c, &znode->zbranch[nn].key, key))
|
| 1109 | return 0;
|
| 1110 | *zn = znode;
|
| 1111 | *n = nn;
|
| 1112 | if (matches_position(&znode->zbranch[nn], lnum, offs))
|
| 1113 | return 1;
|
| 1114 | }
|
| 1115 | }
|
| 1116 |
|
| 1117 | |
| 1118 | * dirty_cow_bottom_up - dirty a znode and its ancestors.
|
| 1119 | * @c: UBIFS file-system description object
|
| 1120 | * @znode: znode to dirty
|
| 1121 | *
|
| 1122 | * If we do not have a unique key that resides in a znode, then we cannot
|
| 1123 | * dirty that znode from the top down (i.e. by using lookup_level0_dirty)
|
| 1124 | * This function records the path back to the last dirty ancestor, and then
|
| 1125 | * dirties the znodes on that path.
|
| 1126 |
|
| 1127 | static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c,
|
| 1128 | struct ubifs_znode *znode)
|
| 1129 | {
|
| 1130 | struct ubifs_znode *zp;
|
| 1131 | int *path = c->bottom_up_buf, p = 0;
|
| 1132 |
|
| 1133 | ubifs_assert(c, c->zroot.znode);
|
| 1134 | ubifs_assert(c, znode);
|
| 1135 | if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) {
|
| 1136 | kfree(c->bottom_up_buf);
|
| 1137 | c->bottom_up_buf = kmalloc_objs(int, c->zroot.znode->level,
|
| 1138 | GFP_NOFS);
|
| 1139 | if (!c->bottom_up_buf)
|
| 1140 | return ERR_PTR(-ENOMEM);
|
| 1141 | path = c->bottom_up_buf;
|
| 1142 | }
|
| 1143 | if (c->zroot.znode->level) {
|
| 1144 |
|
| 1145 | while (1) {
|
| 1146 | int n;
|
| 1147 |
|
| 1148 | zp = znode->parent;
|
| 1149 | if (!zp)
|
| 1150 | break;
|
| 1151 | n = znode->iip;
|
| 1152 | ubifs_assert(c, p < c->zroot.znode->level);
|
| 1153 | path[p++] = n;
|
| 1154 | if (!zp->cnext && ubifs_zn_dirty(znode))
|
| 1155 | break;
|
| 1156 | znode = zp;
|
| 1157 | }
|
| 1158 | }
|
| 1159 |
|
| 1160 |
|
| 1161 | while (1) {
|
| 1162 | struct ubifs_zbranch *zbr;
|
| 1163 |
|
| 1164 | zp = znode->parent;
|
| 1165 | if (zp) {
|
| 1166 | ubifs_assert(c, path[p - 1] >= 0);
|
| 1167 | ubifs_assert(c, path[p - 1] < zp->child_cnt);
|
| 1168 | zbr = &zp->zbranch[path[--p]];
|
| 1169 | znode = dirty_cow_znode(c, zbr);
|
| 1170 | } else {
|
| 1171 | ubifs_assert(c, znode == c->zroot.znode);
|
| 1172 | znode = dirty_cow_znode(c, &c->zroot);
|
| 1173 | }
|
| 1174 | if (IS_ERR(znode) || !p)
|
| 1175 | break;
|
| 1176 | ubifs_assert(c, path[p - 1] >= 0);
|
| 1177 | ubifs_assert(c, path[p - 1] < znode->child_cnt);
|
| 1178 | znode = znode->zbranch[path[p - 1]].znode;
|
| 1179 | }
|
| 1180 |
|
| 1181 | return znode;
|
| 1182 | }
|
| 1183 |
|
| 1184 | |
| 1185 | * ubifs_lookup_level0 - search for zero-level znode.
|
| 1186 | * @c: UBIFS file-system description object
|
| 1187 | * @key: key to lookup
|
| 1188 | * @zn: znode is returned here
|
| 1189 | * @n: znode branch slot number is returned here
|
| 1190 | *
|
| 1191 | * This function looks up the TNC tree and search for zero-level znode which
|
| 1192 | * refers key @key. The found zero-level znode is returned in @zn. There are 3
|
| 1193 | * cases:
|
| 1194 | * o exact match, i.e. the found zero-level znode contains key @key, then %1
|
| 1195 | * is returned and slot number of the matched branch is stored in @n;
|
| 1196 | * o not exact match, which means that zero-level znode does not contain
|
| 1197 | * @key, then %0 is returned and slot number of the closest branch or %-1
|
| 1198 | * is stored in @n; In this case calling tnc_next() is mandatory.
|
| 1199 | * o @key is so small that it is even less than the lowest key of the
|
| 1200 | * leftmost zero-level node, then %0 is returned and %0 is stored in @n.
|
| 1201 | *
|
| 1202 | * Note, when the TNC tree is traversed, some znodes may be absent, then this
|
| 1203 | * function reads corresponding indexing nodes and inserts them to TNC. In
|
| 1204 | * case of failure, a negative error code is returned.
|
| 1205 |
|
| 1206 | int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
|
| 1207 | struct ubifs_znode **zn, int *n)
|
| 1208 | {
|
| 1209 | int err, exact;
|
| 1210 | struct ubifs_znode *znode;
|
| 1211 | time64_t time = ktime_get_seconds();
|
| 1212 |
|
| 1213 | dbg_tnck(key, "search key ");
|
| 1214 | ubifs_assert(c, key_type(c, key) < UBIFS_INVALID_KEY);
|
| 1215 |
|
| 1216 | znode = c->zroot.znode;
|
| 1217 | if (unlikely(!znode)) {
|
| 1218 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
|
| 1219 | if (IS_ERR(znode))
|
| 1220 | return PTR_ERR(znode);
|
| 1221 | }
|
| 1222 |
|
| 1223 | znode->time = time;
|
| 1224 |
|
| 1225 | while (1) {
|
| 1226 | struct ubifs_zbranch *zbr;
|
| 1227 |
|
| 1228 | exact = ubifs_search_zbranch(c, znode, key, n);
|
| 1229 |
|
| 1230 | if (znode->level == 0)
|
| 1231 | break;
|
| 1232 |
|
| 1233 | if (*n < 0)
|
| 1234 | *n = 0;
|
| 1235 | zbr = &znode->zbranch[*n];
|
| 1236 |
|
| 1237 | if (zbr->znode) {
|
| 1238 | znode->time = time;
|
| 1239 | znode = zbr->znode;
|
| 1240 | continue;
|
| 1241 | }
|
| 1242 |
|
| 1243 |
|
| 1244 | znode = ubifs_load_znode(c, zbr, znode, *n);
|
| 1245 | if (IS_ERR(znode))
|
| 1246 | return PTR_ERR(znode);
|
| 1247 | }
|
| 1248 |
|
| 1249 | *zn = znode;
|
| 1250 | if (exact || !is_hash_key(c, key) || *n != -1) {
|
| 1251 | dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n);
|
| 1252 | return exact;
|
| 1253 | }
|
| 1254 |
|
| 1255 | |
| 1256 | * Here is a tricky place. We have not found the key and this is a
|
| 1257 | * "hashed" key, which may collide. The rest of the code deals with
|
| 1258 | * situations like this:
|
| 1259 | *
|
| 1260 | * | 3 | 5 |
|
| 1261 | * / \
|
| 1262 | * | 3 | 5 | | 6 | 7 | (x)
|
| 1263 | *
|
| 1264 | * Or more a complex example:
|
| 1265 | *
|
| 1266 | * | 1 | 5 |
|
| 1267 | * / \
|
| 1268 | * | 1 | 3 | | 5 | 8 |
|
| 1269 | * \ /
|
| 1270 | * | 5 | 5 | | 6 | 7 | (x)
|
| 1271 | *
|
| 1272 | * In the examples, if we are looking for key "5", we may reach nodes
|
| 1273 | * marked with "(x)". In this case what we have do is to look at the
|
| 1274 | * left and see if there is "5" key there. If there is, we have to
|
| 1275 | * return it.
|
| 1276 | *
|
| 1277 | * Note, this whole situation is possible because we allow to have
|
| 1278 | * elements which are equivalent to the next key in the parent in the
|
| 1279 | * children of current znode. For example, this happens if we split a
|
| 1280 | * znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something
|
| 1281 | * like this:
|
| 1282 | * | 3 | 5 |
|
| 1283 | * / \
|
| 1284 | * | 3 | 5 | | 5 | 6 | 7 |
|
| 1285 | * ^
|
| 1286 | * And this becomes what is at the first "picture" after key "5" marked
|
| 1287 | * with "^" is removed. What could be done is we could prohibit
|
| 1288 | * splitting in the middle of the colliding sequence. Also, when
|
| 1289 | * removing the leftmost key, we would have to correct the key of the
|
| 1290 | * parent node, which would introduce additional complications. Namely,
|
| 1291 | * if we changed the leftmost key of the parent znode, the garbage
|
| 1292 | * collector would be unable to find it (GC is doing this when GC'ing
|
| 1293 | * indexing LEBs). Although we already have an additional RB-tree where
|
| 1294 | * we save such changed znodes (see 'ins_clr_old_idx_znode()') until
|
| 1295 | * after the commit. But anyway, this does not look easy to implement
|
| 1296 | * so we did not try this.
|
| 1297 |
|
| 1298 | err = tnc_prev(c, &znode, n);
|
| 1299 | if (err == -ENOENT) {
|
| 1300 | dbg_tnc("found 0, lvl %d, n -1", znode->level);
|
| 1301 | *n = -1;
|
| 1302 | return 0;
|
| 1303 | }
|
| 1304 | if (unlikely(err < 0))
|
| 1305 | return err;
|
| 1306 | if (keys_cmp(c, key, &znode->zbranch[*n].key)) {
|
| 1307 | dbg_tnc("found 0, lvl %d, n -1", znode->level);
|
| 1308 | *n = -1;
|
| 1309 | return 0;
|
| 1310 | }
|
| 1311 |
|
| 1312 | dbg_tnc("found 1, lvl %d, n %d", znode->level, *n);
|
| 1313 | *zn = znode;
|
| 1314 | return 1;
|
| 1315 | }
|
| 1316 |
|
| 1317 | |
| 1318 | * lookup_level0_dirty - search for zero-level znode dirtying.
|
| 1319 | * @c: UBIFS file-system description object
|
| 1320 | * @key: key to lookup
|
| 1321 | * @zn: znode is returned here
|
| 1322 | * @n: znode branch slot number is returned here
|
| 1323 | *
|
| 1324 | * This function looks up the TNC tree and search for zero-level znode which
|
| 1325 | * refers key @key. The found zero-level znode is returned in @zn. There are 3
|
| 1326 | * cases:
|
| 1327 | * o exact match, i.e. the found zero-level znode contains key @key, then %1
|
| 1328 | * is returned and slot number of the matched branch is stored in @n;
|
| 1329 | * o not exact match, which means that zero-level znode does not contain @key
|
| 1330 | * then %0 is returned and slot number of the closed branch is stored in
|
| 1331 | * @n;
|
| 1332 | * o @key is so small that it is even less than the lowest key of the
|
| 1333 | * leftmost zero-level node, then %0 is returned and %-1 is stored in @n.
|
| 1334 | *
|
| 1335 | * Additionally all znodes in the path from the root to the located zero-level
|
| 1336 | * znode are marked as dirty.
|
| 1337 | *
|
| 1338 | * Note, when the TNC tree is traversed, some znodes may be absent, then this
|
| 1339 | * function reads corresponding indexing nodes and inserts them to TNC. In
|
| 1340 | * case of failure, a negative error code is returned.
|
| 1341 |
|
| 1342 | static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key,
|
| 1343 | struct ubifs_znode **zn, int *n)
|
| 1344 | {
|
| 1345 | int err, exact;
|
| 1346 | struct ubifs_znode *znode;
|
| 1347 | time64_t time = ktime_get_seconds();
|
| 1348 |
|
| 1349 | dbg_tnck(key, "search and dirty key ");
|
| 1350 |
|
| 1351 | znode = c->zroot.znode;
|
| 1352 | if (unlikely(!znode)) {
|
| 1353 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
|
| 1354 | if (IS_ERR(znode))
|
| 1355 | return PTR_ERR(znode);
|
| 1356 | }
|
| 1357 |
|
| 1358 | znode = dirty_cow_znode(c, &c->zroot);
|
| 1359 | if (IS_ERR(znode))
|
| 1360 | return PTR_ERR(znode);
|
| 1361 |
|
| 1362 | znode->time = time;
|
| 1363 |
|
| 1364 | while (1) {
|
| 1365 | struct ubifs_zbranch *zbr;
|
| 1366 |
|
| 1367 | exact = ubifs_search_zbranch(c, znode, key, n);
|
| 1368 |
|
| 1369 | if (znode->level == 0)
|
| 1370 | break;
|
| 1371 |
|
| 1372 | if (*n < 0)
|
| 1373 | *n = 0;
|
| 1374 | zbr = &znode->zbranch[*n];
|
| 1375 |
|
| 1376 | if (zbr->znode) {
|
| 1377 | znode->time = time;
|
| 1378 | znode = dirty_cow_znode(c, zbr);
|
| 1379 | if (IS_ERR(znode))
|
| 1380 | return PTR_ERR(znode);
|
| 1381 | continue;
|
| 1382 | }
|
| 1383 |
|
| 1384 |
|
| 1385 | znode = ubifs_load_znode(c, zbr, znode, *n);
|
| 1386 | if (IS_ERR(znode))
|
| 1387 | return PTR_ERR(znode);
|
| 1388 | znode = dirty_cow_znode(c, zbr);
|
| 1389 | if (IS_ERR(znode))
|
| 1390 | return PTR_ERR(znode);
|
| 1391 | }
|
| 1392 |
|
| 1393 | *zn = znode;
|
| 1394 | if (exact || !is_hash_key(c, key) || *n != -1) {
|
| 1395 | dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n);
|
| 1396 | return exact;
|
| 1397 | }
|
| 1398 |
|
| 1399 | |
| 1400 | * See huge comment at 'lookup_level0_dirty()' what is the rest of the
|
| 1401 | * code.
|
| 1402 |
|
| 1403 | err = tnc_prev(c, &znode, n);
|
| 1404 | if (err == -ENOENT) {
|
| 1405 | *n = -1;
|
| 1406 | dbg_tnc("found 0, lvl %d, n -1", znode->level);
|
| 1407 | return 0;
|
| 1408 | }
|
| 1409 | if (unlikely(err < 0))
|
| 1410 | return err;
|
| 1411 | if (keys_cmp(c, key, &znode->zbranch[*n].key)) {
|
| 1412 | *n = -1;
|
| 1413 | dbg_tnc("found 0, lvl %d, n -1", znode->level);
|
| 1414 | return 0;
|
| 1415 | }
|
| 1416 |
|
| 1417 | if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
| 1418 | znode = dirty_cow_bottom_up(c, znode);
|
| 1419 | if (IS_ERR(znode))
|
| 1420 | return PTR_ERR(znode);
|
| 1421 | }
|
| 1422 |
|
| 1423 | dbg_tnc("found 1, lvl %d, n %d", znode->level, *n);
|
| 1424 | *zn = znode;
|
| 1425 | return 1;
|
| 1426 | }
|
| 1427 |
|
| 1428 | |
| 1429 | * maybe_leb_gced - determine if a LEB may have been garbage collected.
|
| 1430 | * @c: UBIFS file-system description object
|
| 1431 | * @lnum: LEB number
|
| 1432 | * @gc_seq1: garbage collection sequence number
|
| 1433 | *
|
| 1434 | * This function determines if @lnum may have been garbage collected since
|
| 1435 | * sequence number @gc_seq1. If it may have been then %1 is returned, otherwise
|
| 1436 | * %0 is returned.
|
| 1437 |
|
| 1438 | static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1)
|
| 1439 | {
|
| 1440 | int gc_seq2, gced_lnum;
|
| 1441 |
|
| 1442 | gced_lnum = c->gced_lnum;
|
| 1443 | smp_rmb();
|
| 1444 | gc_seq2 = c->gc_seq;
|
| 1445 |
|
| 1446 | if (gc_seq1 == gc_seq2)
|
| 1447 | return 0;
|
| 1448 |
|
| 1449 | if (gc_seq1 + 1 != gc_seq2)
|
| 1450 | return 1;
|
| 1451 | |
| 1452 | * We have seen the sequence number has increased by 1. Now we need to
|
| 1453 | * be sure we read the right LEB number, so read it again.
|
| 1454 |
|
| 1455 | smp_rmb();
|
| 1456 | if (gced_lnum != c->gced_lnum)
|
| 1457 | return 1;
|
| 1458 |
|
| 1459 | if (gced_lnum == lnum)
|
| 1460 | return 1;
|
| 1461 | return 0;
|
| 1462 | }
|
| 1463 |
|
| 1464 | |
| 1465 | * ubifs_tnc_locate - look up a file-system node and return it and its location.
|
| 1466 | * @c: UBIFS file-system description object
|
| 1467 | * @key: node key to lookup
|
| 1468 | * @node: the node is returned here
|
| 1469 | * @lnum: LEB number is returned here
|
| 1470 | * @offs: offset is returned here
|
| 1471 | *
|
| 1472 | * This function looks up and reads node with key @key. The caller has to make
|
| 1473 | * sure the @node buffer is large enough to fit the node. Returns zero in case
|
| 1474 | * of success, %-ENOENT if the node was not found, and a negative error code in
|
| 1475 | * case of failure. The node location can be returned in @lnum and @offs.
|
| 1476 |
|
| 1477 | int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key,
|
| 1478 | void *node, int *lnum, int *offs)
|
| 1479 | {
|
| 1480 | int found, n, err, safely = 0, gc_seq1;
|
| 1481 | struct ubifs_znode *znode;
|
| 1482 | struct ubifs_zbranch zbr, *zt;
|
| 1483 |
|
| 1484 | again:
|
| 1485 | mutex_lock(&c->tnc_mutex);
|
| 1486 | found = ubifs_lookup_level0(c, key, &znode, &n);
|
| 1487 | if (!found) {
|
| 1488 | err = -ENOENT;
|
| 1489 | goto out;
|
| 1490 | } else if (found < 0) {
|
| 1491 | err = found;
|
| 1492 | goto out;
|
| 1493 | }
|
| 1494 | zt = &znode->zbranch[n];
|
| 1495 | if (lnum) {
|
| 1496 | *lnum = zt->lnum;
|
| 1497 | *offs = zt->offs;
|
| 1498 | }
|
| 1499 | if (is_hash_key(c, key)) {
|
| 1500 | |
| 1501 | * In this case the leaf node cache gets used, so we pass the
|
| 1502 | * address of the zbranch and keep the mutex locked
|
| 1503 |
|
| 1504 | err = tnc_read_hashed_node(c, zt, node);
|
| 1505 | goto out;
|
| 1506 | }
|
| 1507 | if (safely) {
|
| 1508 | err = ubifs_tnc_read_node(c, zt, node);
|
| 1509 | goto out;
|
| 1510 | }
|
| 1511 |
|
| 1512 | zbr = znode->zbranch[n];
|
| 1513 | gc_seq1 = c->gc_seq;
|
| 1514 | mutex_unlock(&c->tnc_mutex);
|
| 1515 |
|
| 1516 | if (ubifs_get_wbuf(c, zbr.lnum)) {
|
| 1517 |
|
| 1518 | err = ubifs_tnc_read_node(c, &zbr, node);
|
| 1519 | return err;
|
| 1520 | }
|
| 1521 |
|
| 1522 | err = fallible_read_node(c, key, &zbr, node);
|
| 1523 | if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) {
|
| 1524 | |
| 1525 | * The node may have been GC'ed out from under us so try again
|
| 1526 | * while keeping the TNC mutex locked.
|
| 1527 |
|
| 1528 | safely = 1;
|
| 1529 | goto again;
|
| 1530 | }
|
| 1531 | return 0;
|
| 1532 |
|
| 1533 | out:
|
| 1534 | mutex_unlock(&c->tnc_mutex);
|
| 1535 | return err;
|
| 1536 | }
|
| 1537 |
|
| 1538 | |
| 1539 | * ubifs_tnc_get_bu_keys - lookup keys for bulk-read.
|
| 1540 | * @c: UBIFS file-system description object
|
| 1541 | * @bu: bulk-read parameters and results
|
| 1542 | *
|
| 1543 | * Lookup consecutive data node keys for the same inode that reside
|
| 1544 | * consecutively in the same LEB. This function returns zero in case of success
|
| 1545 | * and a negative error code in case of failure.
|
| 1546 | *
|
| 1547 | * Note, if the bulk-read buffer length (@bu->buf_len) is known, this function
|
| 1548 | * makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares
|
| 1549 | * maximum possible amount of nodes for bulk-read.
|
| 1550 |
|
| 1551 | int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu)
|
| 1552 | {
|
| 1553 | int n, err = 0, lnum = -1, offs;
|
| 1554 | int len;
|
| 1555 | unsigned int block = key_block(c, &bu->key);
|
| 1556 | struct ubifs_znode *znode;
|
| 1557 |
|
| 1558 | bu->cnt = 0;
|
| 1559 | bu->blk_cnt = 0;
|
| 1560 | bu->eof = 0;
|
| 1561 |
|
| 1562 | mutex_lock(&c->tnc_mutex);
|
| 1563 |
|
| 1564 | err = ubifs_lookup_level0(c, &bu->key, &znode, &n);
|
| 1565 | if (err < 0)
|
| 1566 | goto out;
|
| 1567 | if (err) {
|
| 1568 |
|
| 1569 | len = znode->zbranch[n].len;
|
| 1570 |
|
| 1571 | if (len > bu->buf_len) {
|
| 1572 | err = -EINVAL;
|
| 1573 | goto out;
|
| 1574 | }
|
| 1575 |
|
| 1576 | bu->zbranch[bu->cnt++] = znode->zbranch[n];
|
| 1577 | bu->blk_cnt += 1;
|
| 1578 | lnum = znode->zbranch[n].lnum;
|
| 1579 | offs = ALIGN(znode->zbranch[n].offs + len, 8);
|
| 1580 | }
|
| 1581 | while (1) {
|
| 1582 | struct ubifs_zbranch *zbr;
|
| 1583 | union ubifs_key *key;
|
| 1584 | unsigned int next_block;
|
| 1585 |
|
| 1586 |
|
| 1587 | err = tnc_next(c, &znode, &n);
|
| 1588 | if (err)
|
| 1589 | goto out;
|
| 1590 | zbr = &znode->zbranch[n];
|
| 1591 | key = &zbr->key;
|
| 1592 |
|
| 1593 | if (key_inum(c, key) != key_inum(c, &bu->key) ||
|
| 1594 | key_type(c, key) != UBIFS_DATA_KEY) {
|
| 1595 | err = -ENOENT;
|
| 1596 | goto out;
|
| 1597 | }
|
| 1598 | if (lnum < 0) {
|
| 1599 |
|
| 1600 | lnum = zbr->lnum;
|
| 1601 | offs = ALIGN(zbr->offs + zbr->len, 8);
|
| 1602 | len = zbr->len;
|
| 1603 | if (len > bu->buf_len) {
|
| 1604 | err = -EINVAL;
|
| 1605 | goto out;
|
| 1606 | }
|
| 1607 | } else {
|
| 1608 | |
| 1609 | * The data nodes must be in consecutive positions in
|
| 1610 | * the same LEB.
|
| 1611 |
|
| 1612 | if (zbr->lnum != lnum || zbr->offs != offs)
|
| 1613 | goto out;
|
| 1614 | offs += ALIGN(zbr->len, 8);
|
| 1615 | len = ALIGN(len, 8) + zbr->len;
|
| 1616 |
|
| 1617 | if (len > bu->buf_len)
|
| 1618 | goto out;
|
| 1619 | }
|
| 1620 |
|
| 1621 | next_block = key_block(c, key);
|
| 1622 | bu->blk_cnt += (next_block - block - 1);
|
| 1623 | if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
|
| 1624 | goto out;
|
| 1625 | block = next_block;
|
| 1626 |
|
| 1627 | bu->zbranch[bu->cnt++] = *zbr;
|
| 1628 | bu->blk_cnt += 1;
|
| 1629 |
|
| 1630 | if (bu->cnt >= UBIFS_MAX_BULK_READ)
|
| 1631 | goto out;
|
| 1632 | if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
|
| 1633 | goto out;
|
| 1634 | }
|
| 1635 | out:
|
| 1636 | if (err == -ENOENT) {
|
| 1637 | bu->eof = 1;
|
| 1638 | err = 0;
|
| 1639 | }
|
| 1640 | bu->gc_seq = c->gc_seq;
|
| 1641 | mutex_unlock(&c->tnc_mutex);
|
| 1642 | if (err)
|
| 1643 | return err;
|
| 1644 | |
| 1645 | * An enormous hole could cause bulk-read to encompass too many
|
| 1646 | * page cache pages, so limit the number here.
|
| 1647 |
|
| 1648 | if (bu->blk_cnt > UBIFS_MAX_BULK_READ)
|
| 1649 | bu->blk_cnt = UBIFS_MAX_BULK_READ;
|
| 1650 | |
| 1651 | * Ensure that bulk-read covers a whole number of page cache
|
| 1652 | * pages.
|
| 1653 |
|
| 1654 | if (UBIFS_BLOCKS_PER_PAGE == 1 ||
|
| 1655 | !(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1)))
|
| 1656 | return 0;
|
| 1657 | if (bu->eof) {
|
| 1658 |
|
| 1659 | bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1;
|
| 1660 | return 0;
|
| 1661 | }
|
| 1662 |
|
| 1663 | block = key_block(c, &bu->key) + bu->blk_cnt;
|
| 1664 | block &= ~(UBIFS_BLOCKS_PER_PAGE - 1);
|
| 1665 | while (bu->cnt) {
|
| 1666 | if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block)
|
| 1667 | break;
|
| 1668 | bu->cnt -= 1;
|
| 1669 | }
|
| 1670 | return 0;
|
| 1671 | }
|
| 1672 |
|
| 1673 | |
| 1674 | * read_wbuf - bulk-read from a LEB with a wbuf.
|
| 1675 | * @wbuf: wbuf that may overlap the read
|
| 1676 | * @buf: buffer into which to read
|
| 1677 | * @len: read length
|
| 1678 | * @lnum: LEB number from which to read
|
| 1679 | * @offs: offset from which to read
|
| 1680 | *
|
| 1681 | * This functions returns %0 on success or a negative error code on failure.
|
| 1682 |
|
| 1683 | static int read_wbuf(struct ubifs_wbuf *wbuf, void *buf, int len, int lnum,
|
| 1684 | int offs)
|
| 1685 | {
|
| 1686 | const struct ubifs_info *c = wbuf->c;
|
| 1687 | int rlen, overlap;
|
| 1688 |
|
| 1689 | dbg_io("LEB %d:%d, length %d", lnum, offs, len);
|
| 1690 | ubifs_assert(c, wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
|
| 1691 | ubifs_assert(c, !(offs & 7) && offs < c->leb_size);
|
| 1692 | ubifs_assert(c, offs + len <= c->leb_size);
|
| 1693 |
|
| 1694 | spin_lock(&wbuf->lock);
|
| 1695 | overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs);
|
| 1696 | if (!overlap) {
|
| 1697 |
|
| 1698 | spin_unlock(&wbuf->lock);
|
| 1699 | return ubifs_leb_read(c, lnum, buf, offs, len, 0);
|
| 1700 | }
|
| 1701 |
|
| 1702 |
|
| 1703 | rlen = wbuf->offs - offs;
|
| 1704 | if (rlen < 0)
|
| 1705 | rlen = 0;
|
| 1706 |
|
| 1707 |
|
| 1708 | memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen);
|
| 1709 | spin_unlock(&wbuf->lock);
|
| 1710 |
|
| 1711 | if (rlen > 0)
|
| 1712 |
|
| 1713 | return ubifs_leb_read(c, lnum, buf, offs, rlen, 0);
|
| 1714 |
|
| 1715 | return 0;
|
| 1716 | }
|
| 1717 |
|
| 1718 | |
| 1719 | * validate_data_node - validate data nodes for bulk-read.
|
| 1720 | * @c: UBIFS file-system description object
|
| 1721 | * @buf: buffer containing data node to validate
|
| 1722 | * @zbr: zbranch of data node to validate
|
| 1723 | *
|
| 1724 | * This functions returns %0 on success or a negative error code on failure.
|
| 1725 |
|
| 1726 | static int validate_data_node(struct ubifs_info *c, void *buf,
|
| 1727 | struct ubifs_zbranch *zbr)
|
| 1728 | {
|
| 1729 | union ubifs_key key1;
|
| 1730 | struct ubifs_ch *ch = buf;
|
| 1731 | int err, len;
|
| 1732 |
|
| 1733 | if (ch->node_type != UBIFS_DATA_NODE) {
|
| 1734 | ubifs_err(c, "bad node type (%d but expected %d)",
|
| 1735 | ch->node_type, UBIFS_DATA_NODE);
|
| 1736 | goto out_err;
|
| 1737 | }
|
| 1738 |
|
| 1739 | err = ubifs_check_node(c, buf, zbr->len, zbr->lnum, zbr->offs, 0, 0);
|
| 1740 | if (err) {
|
| 1741 | ubifs_err(c, "expected node type %d", UBIFS_DATA_NODE);
|
| 1742 | goto out;
|
| 1743 | }
|
| 1744 |
|
| 1745 | err = ubifs_node_check_hash(c, buf, zbr->hash);
|
| 1746 | if (err) {
|
| 1747 | ubifs_bad_hash(c, buf, zbr->hash, zbr->lnum, zbr->offs);
|
| 1748 | return err;
|
| 1749 | }
|
| 1750 |
|
| 1751 | len = le32_to_cpu(ch->len);
|
| 1752 | if (len != zbr->len) {
|
| 1753 | ubifs_err(c, "bad node length %d, expected %d", len, zbr->len);
|
| 1754 | goto out_err;
|
| 1755 | }
|
| 1756 |
|
| 1757 |
|
| 1758 | key_read(c, buf + UBIFS_KEY_OFFSET, &key1);
|
| 1759 | if (!keys_eq(c, &zbr->key, &key1)) {
|
| 1760 | ubifs_err(c, "bad key in node at LEB %d:%d",
|
| 1761 | zbr->lnum, zbr->offs);
|
| 1762 | dbg_tnck(&zbr->key, "looked for key ");
|
| 1763 | dbg_tnck(&key1, "found node's key ");
|
| 1764 | goto out_err;
|
| 1765 | }
|
| 1766 |
|
| 1767 | return 0;
|
| 1768 |
|
| 1769 | out_err:
|
| 1770 | err = -EINVAL;
|
| 1771 | out:
|
| 1772 | ubifs_err(c, "bad node at LEB %d:%d", zbr->lnum, zbr->offs);
|
| 1773 | ubifs_dump_node(c, buf, zbr->len);
|
| 1774 | dump_stack();
|
| 1775 | return err;
|
| 1776 | }
|
| 1777 |
|
| 1778 | |
| 1779 | * ubifs_tnc_bulk_read - read a number of data nodes in one go.
|
| 1780 | * @c: UBIFS file-system description object
|
| 1781 | * @bu: bulk-read parameters and results
|
| 1782 | *
|
| 1783 | * This functions reads and validates the data nodes that were identified by the
|
| 1784 | * 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success,
|
| 1785 | * -EAGAIN to indicate a race with GC, or another negative error code on
|
| 1786 | * failure.
|
| 1787 |
|
| 1788 | int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu)
|
| 1789 | {
|
| 1790 | int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i;
|
| 1791 | struct ubifs_wbuf *wbuf;
|
| 1792 | void *buf;
|
| 1793 |
|
| 1794 | len = bu->zbranch[bu->cnt - 1].offs;
|
| 1795 | len += bu->zbranch[bu->cnt - 1].len - offs;
|
| 1796 | if (len > bu->buf_len) {
|
| 1797 | ubifs_err(c, "buffer too small %d vs %d", bu->buf_len, len);
|
| 1798 | return -EINVAL;
|
| 1799 | }
|
| 1800 |
|
| 1801 |
|
| 1802 | wbuf = ubifs_get_wbuf(c, lnum);
|
| 1803 | if (wbuf)
|
| 1804 | err = read_wbuf(wbuf, bu->buf, len, lnum, offs);
|
| 1805 | else
|
| 1806 | err = ubifs_leb_read(c, lnum, bu->buf, offs, len, 0);
|
| 1807 |
|
| 1808 |
|
| 1809 | if (maybe_leb_gced(c, lnum, bu->gc_seq))
|
| 1810 | return -EAGAIN;
|
| 1811 |
|
| 1812 | if (err && err != -EBADMSG) {
|
| 1813 | ubifs_err(c, "failed to read from LEB %d:%d, error %d",
|
| 1814 | lnum, offs, err);
|
| 1815 | dump_stack();
|
| 1816 | dbg_tnck(&bu->key, "key ");
|
| 1817 | return err;
|
| 1818 | }
|
| 1819 |
|
| 1820 |
|
| 1821 | buf = bu->buf;
|
| 1822 | for (i = 0; i < bu->cnt; i++) {
|
| 1823 | err = validate_data_node(c, buf, &bu->zbranch[i]);
|
| 1824 | if (err)
|
| 1825 | return err;
|
| 1826 | buf = buf + ALIGN(bu->zbranch[i].len, 8);
|
| 1827 | }
|
| 1828 |
|
| 1829 | return 0;
|
| 1830 | }
|
| 1831 |
|
| 1832 | |
| 1833 | * do_lookup_nm- look up a "hashed" node.
|
| 1834 | * @c: UBIFS file-system description object
|
| 1835 | * @key: node key to lookup
|
| 1836 | * @node: the node is returned here
|
| 1837 | * @nm: node name
|
| 1838 | *
|
| 1839 | * This function looks up and reads a node which contains name hash in the key.
|
| 1840 | * Since the hash may have collisions, there may be many nodes with the same
|
| 1841 | * key, so we have to sequentially look to all of them until the needed one is
|
| 1842 | * found. This function returns zero in case of success, %-ENOENT if the node
|
| 1843 | * was not found, and a negative error code in case of failure.
|
| 1844 |
|
| 1845 | static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
|
| 1846 | void *node, const struct fscrypt_name *nm)
|
| 1847 | {
|
| 1848 | int found, n, err;
|
| 1849 | struct ubifs_znode *znode;
|
| 1850 |
|
| 1851 | dbg_tnck(key, "key ");
|
| 1852 | mutex_lock(&c->tnc_mutex);
|
| 1853 | found = ubifs_lookup_level0(c, key, &znode, &n);
|
| 1854 | if (!found) {
|
| 1855 | err = -ENOENT;
|
| 1856 | goto out_unlock;
|
| 1857 | } else if (found < 0) {
|
| 1858 | err = found;
|
| 1859 | goto out_unlock;
|
| 1860 | }
|
| 1861 |
|
| 1862 | ubifs_assert(c, n >= 0);
|
| 1863 |
|
| 1864 | err = resolve_collision(c, key, &znode, &n, nm);
|
| 1865 | dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n);
|
| 1866 | if (unlikely(err < 0))
|
| 1867 | goto out_unlock;
|
| 1868 | if (err == 0) {
|
| 1869 | err = -ENOENT;
|
| 1870 | goto out_unlock;
|
| 1871 | }
|
| 1872 |
|
| 1873 | err = tnc_read_hashed_node(c, &znode->zbranch[n], node);
|
| 1874 |
|
| 1875 | out_unlock:
|
| 1876 | mutex_unlock(&c->tnc_mutex);
|
| 1877 | return err;
|
| 1878 | }
|
| 1879 |
|
| 1880 | |
| 1881 | * ubifs_tnc_lookup_nm - look up a "hashed" node.
|
| 1882 | * @c: UBIFS file-system description object
|
| 1883 | * @key: node key to lookup
|
| 1884 | * @node: the node is returned here
|
| 1885 | * @nm: node name
|
| 1886 | *
|
| 1887 | * This function looks up and reads a node which contains name hash in the key.
|
| 1888 | * Since the hash may have collisions, there may be many nodes with the same
|
| 1889 | * key, so we have to sequentially look to all of them until the needed one is
|
| 1890 | * found. This function returns zero in case of success, %-ENOENT if the node
|
| 1891 | * was not found, and a negative error code in case of failure.
|
| 1892 |
|
| 1893 | int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
|
| 1894 | void *node, const struct fscrypt_name *nm)
|
| 1895 | {
|
| 1896 | int err, len;
|
| 1897 | const struct ubifs_dent_node *dent = node;
|
| 1898 |
|
| 1899 | |
| 1900 | * We assume that in most of the cases there are no name collisions and
|
| 1901 | * 'ubifs_tnc_lookup()' returns us the right direntry.
|
| 1902 |
|
| 1903 | err = ubifs_tnc_lookup(c, key, node);
|
| 1904 | if (err)
|
| 1905 | return err;
|
| 1906 |
|
| 1907 | len = le16_to_cpu(dent->nlen);
|
| 1908 | if (fname_len(nm) == len && !memcmp(dent->name, fname_name(nm), len))
|
| 1909 | return 0;
|
| 1910 |
|
| 1911 | |
| 1912 | * Unluckily, there are hash collisions and we have to iterate over
|
| 1913 | * them look at each direntry with colliding name hash sequentially.
|
| 1914 |
|
| 1915 |
|
| 1916 | return do_lookup_nm(c, key, node, nm);
|
| 1917 | }
|
| 1918 |
|
| 1919 | static int search_dh_cookie(struct ubifs_info *c, const union ubifs_key *key,
|
| 1920 | struct ubifs_dent_node *dent, uint32_t cookie,
|
| 1921 | struct ubifs_znode **zn, int *n, int exact)
|
| 1922 | {
|
| 1923 | int err;
|
| 1924 | struct ubifs_znode *znode = *zn;
|
| 1925 | struct ubifs_zbranch *zbr;
|
| 1926 | union ubifs_key *dkey;
|
| 1927 |
|
| 1928 | if (!exact) {
|
| 1929 | err = tnc_next(c, &znode, n);
|
| 1930 | if (err)
|
| 1931 | return err;
|
| 1932 | }
|
| 1933 |
|
| 1934 | for (;;) {
|
| 1935 | zbr = &znode->zbranch[*n];
|
| 1936 | dkey = &zbr->key;
|
| 1937 |
|
| 1938 | if (key_inum(c, dkey) != key_inum(c, key) ||
|
| 1939 | key_type(c, dkey) != key_type(c, key)) {
|
| 1940 | return -ENOENT;
|
| 1941 | }
|
| 1942 |
|
| 1943 | err = tnc_read_hashed_node(c, zbr, dent);
|
| 1944 | if (err)
|
| 1945 | return err;
|
| 1946 |
|
| 1947 | if (key_hash(c, key) == key_hash(c, dkey) &&
|
| 1948 | le32_to_cpu(dent->cookie) == cookie) {
|
| 1949 | *zn = znode;
|
| 1950 | return 0;
|
| 1951 | }
|
| 1952 |
|
| 1953 | err = tnc_next(c, &znode, n);
|
| 1954 | if (err)
|
| 1955 | return err;
|
| 1956 | }
|
| 1957 | }
|
| 1958 |
|
| 1959 | static int do_lookup_dh(struct ubifs_info *c, const union ubifs_key *key,
|
| 1960 | struct ubifs_dent_node *dent, uint32_t cookie)
|
| 1961 | {
|
| 1962 | int n, err;
|
| 1963 | struct ubifs_znode *znode;
|
| 1964 | union ubifs_key start_key;
|
| 1965 |
|
| 1966 | ubifs_assert(c, is_hash_key(c, key));
|
| 1967 |
|
| 1968 | lowest_dent_key(c, &start_key, key_inum(c, key));
|
| 1969 |
|
| 1970 | mutex_lock(&c->tnc_mutex);
|
| 1971 | err = ubifs_lookup_level0(c, &start_key, &znode, &n);
|
| 1972 | if (unlikely(err < 0))
|
| 1973 | goto out_unlock;
|
| 1974 |
|
| 1975 | err = search_dh_cookie(c, key, dent, cookie, &znode, &n, err);
|
| 1976 |
|
| 1977 | out_unlock:
|
| 1978 | mutex_unlock(&c->tnc_mutex);
|
| 1979 | return err;
|
| 1980 | }
|
| 1981 |
|
| 1982 | |
| 1983 | * ubifs_tnc_lookup_dh - look up a "double hashed" node.
|
| 1984 | * @c: UBIFS file-system description object
|
| 1985 | * @key: node key to lookup
|
| 1986 | * @node: the node is returned here
|
| 1987 | * @cookie: node cookie for collision resolution
|
| 1988 | *
|
| 1989 | * This function looks up and reads a node which contains name hash in the key.
|
| 1990 | * Since the hash may have collisions, there may be many nodes with the same
|
| 1991 | * key, so we have to sequentially look to all of them until the needed one
|
| 1992 | * with the same cookie value is found.
|
| 1993 | * This function returns zero in case of success, %-ENOENT if the node
|
| 1994 | * was not found, and a negative error code in case of failure.
|
| 1995 |
|
| 1996 | int ubifs_tnc_lookup_dh(struct ubifs_info *c, const union ubifs_key *key,
|
| 1997 | void *node, uint32_t cookie)
|
| 1998 | {
|
| 1999 | int err;
|
| 2000 | const struct ubifs_dent_node *dent = node;
|
| 2001 |
|
| 2002 | if (!c->double_hash)
|
| 2003 | return -EOPNOTSUPP;
|
| 2004 |
|
| 2005 | |
| 2006 | * We assume that in most of the cases there are no name collisions and
|
| 2007 | * 'ubifs_tnc_lookup()' returns us the right direntry.
|
| 2008 |
|
| 2009 | err = ubifs_tnc_lookup(c, key, node);
|
| 2010 | if (err)
|
| 2011 | return err;
|
| 2012 |
|
| 2013 | if (le32_to_cpu(dent->cookie) == cookie)
|
| 2014 | return 0;
|
| 2015 |
|
| 2016 | |
| 2017 | * Unluckily, there are hash collisions and we have to iterate over
|
| 2018 | * them look at each direntry with colliding name hash sequentially.
|
| 2019 |
|
| 2020 | return do_lookup_dh(c, key, node, cookie);
|
| 2021 | }
|
| 2022 |
|
| 2023 | |
| 2024 | * correct_parent_keys - correct parent znodes' keys.
|
| 2025 | * @c: UBIFS file-system description object
|
| 2026 | * @znode: znode to correct parent znodes for
|
| 2027 | *
|
| 2028 | * This is a helper function for 'tnc_insert()'. When the key of the leftmost
|
| 2029 | * zbranch changes, keys of parent znodes have to be corrected. This helper
|
| 2030 | * function is called in such situations and corrects the keys if needed.
|
| 2031 |
|
| 2032 | static void correct_parent_keys(const struct ubifs_info *c,
|
| 2033 | struct ubifs_znode *znode)
|
| 2034 | {
|
| 2035 | union ubifs_key *key, *key1;
|
| 2036 |
|
| 2037 | ubifs_assert(c, znode->parent);
|
| 2038 | ubifs_assert(c, znode->iip == 0);
|
| 2039 |
|
| 2040 | key = &znode->zbranch[0].key;
|
| 2041 | key1 = &znode->parent->zbranch[0].key;
|
| 2042 |
|
| 2043 | while (keys_cmp(c, key, key1) < 0) {
|
| 2044 | key_copy(c, key, key1);
|
| 2045 | znode = znode->parent;
|
| 2046 | znode->alt = 1;
|
| 2047 | if (!znode->parent || znode->iip)
|
| 2048 | break;
|
| 2049 | key1 = &znode->parent->zbranch[0].key;
|
| 2050 | }
|
| 2051 | }
|
| 2052 |
|
| 2053 | |
| 2054 | * insert_zbranch - insert a zbranch into a znode.
|
| 2055 | * @c: UBIFS file-system description object
|
| 2056 | * @znode: znode into which to insert
|
| 2057 | * @zbr: zbranch to insert
|
| 2058 | * @n: slot number to insert to
|
| 2059 | *
|
| 2060 | * This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in
|
| 2061 | * znode's array of zbranches and keeps zbranches consolidated, so when a new
|
| 2062 | * zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th
|
| 2063 | * slot, zbranches starting from @n have to be moved right.
|
| 2064 |
|
| 2065 | static void insert_zbranch(struct ubifs_info *c, struct ubifs_znode *znode,
|
| 2066 | const struct ubifs_zbranch *zbr, int n)
|
| 2067 | {
|
| 2068 | int i;
|
| 2069 |
|
| 2070 | ubifs_assert(c, ubifs_zn_dirty(znode));
|
| 2071 |
|
| 2072 | if (znode->level) {
|
| 2073 | for (i = znode->child_cnt; i > n; i--) {
|
| 2074 | znode->zbranch[i] = znode->zbranch[i - 1];
|
| 2075 | if (znode->zbranch[i].znode)
|
| 2076 | znode->zbranch[i].znode->iip = i;
|
| 2077 | }
|
| 2078 | if (zbr->znode)
|
| 2079 | zbr->znode->iip = n;
|
| 2080 | } else
|
| 2081 | for (i = znode->child_cnt; i > n; i--)
|
| 2082 | znode->zbranch[i] = znode->zbranch[i - 1];
|
| 2083 |
|
| 2084 | znode->zbranch[n] = *zbr;
|
| 2085 | znode->child_cnt += 1;
|
| 2086 |
|
| 2087 | |
| 2088 | * After inserting at slot zero, the lower bound of the key range of
|
| 2089 | * this znode may have changed. If this znode is subsequently split
|
| 2090 | * then the upper bound of the key range may change, and furthermore
|
| 2091 | * it could change to be lower than the original lower bound. If that
|
| 2092 | * happens, then it will no longer be possible to find this znode in the
|
| 2093 | * TNC using the key from the index node on flash. That is bad because
|
| 2094 | * if it is not found, we will assume it is obsolete and may overwrite
|
| 2095 | * it. Then if there is an unclean unmount, we will start using the
|
| 2096 | * old index which will be broken.
|
| 2097 | *
|
| 2098 | * So we first mark znodes that have insertions at slot zero, and then
|
| 2099 | * if they are split we add their lnum/offs to the old_idx tree.
|
| 2100 |
|
| 2101 | if (n == 0)
|
| 2102 | znode->alt = 1;
|
| 2103 | }
|
| 2104 |
|
| 2105 | |
| 2106 | * tnc_insert - insert a node into TNC.
|
| 2107 | * @c: UBIFS file-system description object
|
| 2108 | * @znode: znode to insert into
|
| 2109 | * @zbr: branch to insert
|
| 2110 | * @n: slot number to insert new zbranch to
|
| 2111 | *
|
| 2112 | * This function inserts a new node described by @zbr into znode @znode. If
|
| 2113 | * znode does not have a free slot for new zbranch, it is split. Parent znodes
|
| 2114 | * are splat as well if needed. Returns zero in case of success or a negative
|
| 2115 | * error code in case of failure.
|
| 2116 |
|
| 2117 | static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode,
|
| 2118 | struct ubifs_zbranch *zbr, int n)
|
| 2119 | {
|
| 2120 | struct ubifs_znode *zn, *zi, *zp;
|
| 2121 | int i, keep, move, appending = 0;
|
| 2122 | union ubifs_key *key = &zbr->key, *key1;
|
| 2123 |
|
| 2124 | ubifs_assert(c, n >= 0 && n <= c->fanout);
|
| 2125 |
|
| 2126 |
|
| 2127 | again:
|
| 2128 | zp = znode->parent;
|
| 2129 | if (znode->child_cnt < c->fanout) {
|
| 2130 | ubifs_assert(c, n != c->fanout);
|
| 2131 | dbg_tnck(key, "inserted at %d level %d, key ", n, znode->level);
|
| 2132 |
|
| 2133 | insert_zbranch(c, znode, zbr, n);
|
| 2134 |
|
| 2135 |
|
| 2136 | if (n == 0 && zp && znode->iip == 0)
|
| 2137 | correct_parent_keys(c, znode);
|
| 2138 |
|
| 2139 | return 0;
|
| 2140 | }
|
| 2141 |
|
| 2142 | |
| 2143 | * Unfortunately, @znode does not have more empty slots and we have to
|
| 2144 | * split it.
|
| 2145 |
|
| 2146 | dbg_tnck(key, "splitting level %d, key ", znode->level);
|
| 2147 |
|
| 2148 | if (znode->alt)
|
| 2149 | |
| 2150 | * We can no longer be sure of finding this znode by key, so we
|
| 2151 | * record it in the old_idx tree.
|
| 2152 |
|
| 2153 | ins_clr_old_idx_znode(c, znode);
|
| 2154 |
|
| 2155 | zn = kzalloc(c->max_znode_sz, GFP_NOFS);
|
| 2156 | if (!zn)
|
| 2157 | return -ENOMEM;
|
| 2158 | zn->parent = zp;
|
| 2159 | zn->level = znode->level;
|
| 2160 |
|
| 2161 |
|
| 2162 | if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) {
|
| 2163 |
|
| 2164 | if (n == c->fanout) {
|
| 2165 | key1 = &znode->zbranch[n - 1].key;
|
| 2166 | if (key_inum(c, key1) == key_inum(c, key) &&
|
| 2167 | key_type(c, key1) == UBIFS_DATA_KEY)
|
| 2168 | appending = 1;
|
| 2169 | } else
|
| 2170 | goto check_split;
|
| 2171 | } else if (appending && n != c->fanout) {
|
| 2172 |
|
| 2173 | appending = 0;
|
| 2174 | check_split:
|
| 2175 | if (n >= (c->fanout + 1) / 2) {
|
| 2176 | key1 = &znode->zbranch[0].key;
|
| 2177 | if (key_inum(c, key1) == key_inum(c, key) &&
|
| 2178 | key_type(c, key1) == UBIFS_DATA_KEY) {
|
| 2179 | key1 = &znode->zbranch[n].key;
|
| 2180 | if (key_inum(c, key1) != key_inum(c, key) ||
|
| 2181 | key_type(c, key1) != UBIFS_DATA_KEY) {
|
| 2182 | keep = n;
|
| 2183 | move = c->fanout - keep;
|
| 2184 | zi = znode;
|
| 2185 | goto do_split;
|
| 2186 | }
|
| 2187 | }
|
| 2188 | }
|
| 2189 | }
|
| 2190 |
|
| 2191 | if (appending) {
|
| 2192 | keep = c->fanout;
|
| 2193 | move = 0;
|
| 2194 | } else {
|
| 2195 | keep = (c->fanout + 1) / 2;
|
| 2196 | move = c->fanout - keep;
|
| 2197 | }
|
| 2198 |
|
| 2199 | |
| 2200 | * Although we don't at present, we could look at the neighbors and see
|
| 2201 | * if we can move some zbranches there.
|
| 2202 |
|
| 2203 |
|
| 2204 | if (n < keep) {
|
| 2205 |
|
| 2206 | zi = znode;
|
| 2207 | move += 1;
|
| 2208 | keep -= 1;
|
| 2209 | } else {
|
| 2210 |
|
| 2211 | zi = zn;
|
| 2212 | n -= keep;
|
| 2213 |
|
| 2214 | if (zn->level != 0)
|
| 2215 | zbr->znode->parent = zn;
|
| 2216 | }
|
| 2217 |
|
| 2218 | do_split:
|
| 2219 |
|
| 2220 | __set_bit(DIRTY_ZNODE, &zn->flags);
|
| 2221 | atomic_long_inc(&c->dirty_zn_cnt);
|
| 2222 |
|
| 2223 | zn->child_cnt = move;
|
| 2224 | znode->child_cnt = keep;
|
| 2225 |
|
| 2226 | dbg_tnc("moving %d, keeping %d", move, keep);
|
| 2227 |
|
| 2228 |
|
| 2229 | for (i = 0; i < move; i++) {
|
| 2230 | zn->zbranch[i] = znode->zbranch[keep + i];
|
| 2231 |
|
| 2232 | if (zn->level != 0)
|
| 2233 | if (zn->zbranch[i].znode) {
|
| 2234 | zn->zbranch[i].znode->parent = zn;
|
| 2235 | zn->zbranch[i].znode->iip = i;
|
| 2236 | }
|
| 2237 | }
|
| 2238 |
|
| 2239 |
|
| 2240 | dbg_tnck(key, "inserting at %d level %d, key ", n, zn->level);
|
| 2241 |
|
| 2242 | insert_zbranch(c, zi, zbr, n);
|
| 2243 |
|
| 2244 |
|
| 2245 | if (zp) {
|
| 2246 | if (n == 0 && zi == znode && znode->iip == 0)
|
| 2247 | correct_parent_keys(c, znode);
|
| 2248 |
|
| 2249 |
|
| 2250 | n = znode->iip + 1;
|
| 2251 |
|
| 2252 |
|
| 2253 | zbr->key = zn->zbranch[0].key;
|
| 2254 | zbr->znode = zn;
|
| 2255 | zbr->lnum = 0;
|
| 2256 | zbr->offs = 0;
|
| 2257 | zbr->len = 0;
|
| 2258 | znode = zp;
|
| 2259 |
|
| 2260 | goto again;
|
| 2261 | }
|
| 2262 |
|
| 2263 |
|
| 2264 | dbg_tnc("creating new zroot at level %d", znode->level + 1);
|
| 2265 |
|
| 2266 | zi = kzalloc(c->max_znode_sz, GFP_NOFS);
|
| 2267 | if (!zi)
|
| 2268 | return -ENOMEM;
|
| 2269 |
|
| 2270 | zi->child_cnt = 2;
|
| 2271 | zi->level = znode->level + 1;
|
| 2272 |
|
| 2273 | __set_bit(DIRTY_ZNODE, &zi->flags);
|
| 2274 | atomic_long_inc(&c->dirty_zn_cnt);
|
| 2275 |
|
| 2276 | zi->zbranch[0].key = znode->zbranch[0].key;
|
| 2277 | zi->zbranch[0].znode = znode;
|
| 2278 | zi->zbranch[0].lnum = c->zroot.lnum;
|
| 2279 | zi->zbranch[0].offs = c->zroot.offs;
|
| 2280 | zi->zbranch[0].len = c->zroot.len;
|
| 2281 | zi->zbranch[1].key = zn->zbranch[0].key;
|
| 2282 | zi->zbranch[1].znode = zn;
|
| 2283 |
|
| 2284 | c->zroot.lnum = 0;
|
| 2285 | c->zroot.offs = 0;
|
| 2286 | c->zroot.len = 0;
|
| 2287 | c->zroot.znode = zi;
|
| 2288 |
|
| 2289 | zn->parent = zi;
|
| 2290 | zn->iip = 1;
|
| 2291 | znode->parent = zi;
|
| 2292 | znode->iip = 0;
|
| 2293 |
|
| 2294 | return 0;
|
| 2295 | }
|
| 2296 |
|
| 2297 | |
| 2298 | * ubifs_tnc_add - add a node to TNC.
|
| 2299 | * @c: UBIFS file-system description object
|
| 2300 | * @key: key to add
|
| 2301 | * @lnum: LEB number of node
|
| 2302 | * @offs: node offset
|
| 2303 | * @len: node length
|
| 2304 | * @hash: The hash over the node
|
| 2305 | *
|
| 2306 | * This function adds a node with key @key to TNC. The node may be new or it may
|
| 2307 | * obsolete some existing one. Returns %0 on success or negative error code on
|
| 2308 | * failure.
|
| 2309 |
|
| 2310 | int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
|
| 2311 | int offs, int len, const u8 *hash)
|
| 2312 | {
|
| 2313 | int found, n, err = 0;
|
| 2314 | struct ubifs_znode *znode;
|
| 2315 |
|
| 2316 | mutex_lock(&c->tnc_mutex);
|
| 2317 | dbg_tnck(key, "%d:%d, len %d, key ", lnum, offs, len);
|
| 2318 | found = lookup_level0_dirty(c, key, &znode, &n);
|
| 2319 | if (!found) {
|
| 2320 | struct ubifs_zbranch zbr;
|
| 2321 |
|
| 2322 | zbr.znode = NULL;
|
| 2323 | zbr.lnum = lnum;
|
| 2324 | zbr.offs = offs;
|
| 2325 | zbr.len = len;
|
| 2326 | ubifs_copy_hash(c, hash, zbr.hash);
|
| 2327 | key_copy(c, key, &zbr.key);
|
| 2328 | err = tnc_insert(c, znode, &zbr, n + 1);
|
| 2329 | } else if (found == 1) {
|
| 2330 | struct ubifs_zbranch *zbr = &znode->zbranch[n];
|
| 2331 |
|
| 2332 | lnc_free(zbr);
|
| 2333 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
|
| 2334 | zbr->lnum = lnum;
|
| 2335 | zbr->offs = offs;
|
| 2336 | zbr->len = len;
|
| 2337 | ubifs_copy_hash(c, hash, zbr->hash);
|
| 2338 | } else
|
| 2339 | err = found;
|
| 2340 | if (!err)
|
| 2341 | err = dbg_check_tnc(c, 0);
|
| 2342 | mutex_unlock(&c->tnc_mutex);
|
| 2343 |
|
| 2344 | return err;
|
| 2345 | }
|
| 2346 |
|
| 2347 | |
| 2348 | * ubifs_tnc_replace - replace a node in the TNC only if the old node is found.
|
| 2349 | * @c: UBIFS file-system description object
|
| 2350 | * @key: key to add
|
| 2351 | * @old_lnum: LEB number of old node
|
| 2352 | * @old_offs: old node offset
|
| 2353 | * @lnum: LEB number of node
|
| 2354 | * @offs: node offset
|
| 2355 | * @len: node length
|
| 2356 | *
|
| 2357 | * This function replaces a node with key @key in the TNC only if the old node
|
| 2358 | * is found. This function is called by garbage collection when node are moved.
|
| 2359 | * Returns %0 on success or negative error code on failure.
|
| 2360 |
|
| 2361 | int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
|
| 2362 | int old_lnum, int old_offs, int lnum, int offs, int len)
|
| 2363 | {
|
| 2364 | int found, n, err = 0;
|
| 2365 | struct ubifs_znode *znode;
|
| 2366 |
|
| 2367 | mutex_lock(&c->tnc_mutex);
|
| 2368 | dbg_tnck(key, "old LEB %d:%d, new LEB %d:%d, len %d, key ", old_lnum,
|
| 2369 | old_offs, lnum, offs, len);
|
| 2370 | found = lookup_level0_dirty(c, key, &znode, &n);
|
| 2371 | if (found < 0) {
|
| 2372 | err = found;
|
| 2373 | goto out_unlock;
|
| 2374 | }
|
| 2375 |
|
| 2376 | if (found == 1) {
|
| 2377 | struct ubifs_zbranch *zbr = &znode->zbranch[n];
|
| 2378 |
|
| 2379 | found = 0;
|
| 2380 | if (zbr->lnum == old_lnum && zbr->offs == old_offs) {
|
| 2381 | lnc_free(zbr);
|
| 2382 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
|
| 2383 | if (err)
|
| 2384 | goto out_unlock;
|
| 2385 | zbr->lnum = lnum;
|
| 2386 | zbr->offs = offs;
|
| 2387 | zbr->len = len;
|
| 2388 | found = 1;
|
| 2389 | } else if (is_hash_key(c, key)) {
|
| 2390 | found = resolve_collision_directly(c, key, &znode, &n,
|
| 2391 | old_lnum, old_offs);
|
| 2392 | dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d",
|
| 2393 | found, znode, n, old_lnum, old_offs);
|
| 2394 | if (found < 0) {
|
| 2395 | err = found;
|
| 2396 | goto out_unlock;
|
| 2397 | }
|
| 2398 |
|
| 2399 | if (found) {
|
| 2400 |
|
| 2401 | if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
| 2402 | znode = dirty_cow_bottom_up(c, znode);
|
| 2403 | if (IS_ERR(znode)) {
|
| 2404 | err = PTR_ERR(znode);
|
| 2405 | goto out_unlock;
|
| 2406 | }
|
| 2407 | }
|
| 2408 | zbr = &znode->zbranch[n];
|
| 2409 | lnc_free(zbr);
|
| 2410 | err = ubifs_add_dirt(c, zbr->lnum,
|
| 2411 | zbr->len);
|
| 2412 | if (err)
|
| 2413 | goto out_unlock;
|
| 2414 | zbr->lnum = lnum;
|
| 2415 | zbr->offs = offs;
|
| 2416 | zbr->len = len;
|
| 2417 | }
|
| 2418 | }
|
| 2419 | }
|
| 2420 |
|
| 2421 | if (!found)
|
| 2422 | err = ubifs_add_dirt(c, lnum, len);
|
| 2423 |
|
| 2424 | if (!err)
|
| 2425 | err = dbg_check_tnc(c, 0);
|
| 2426 |
|
| 2427 | out_unlock:
|
| 2428 | mutex_unlock(&c->tnc_mutex);
|
| 2429 | return err;
|
| 2430 | }
|
| 2431 |
|
| 2432 | |
| 2433 | * ubifs_tnc_add_nm - add a "hashed" node to TNC.
|
| 2434 | * @c: UBIFS file-system description object
|
| 2435 | * @key: key to add
|
| 2436 | * @lnum: LEB number of node
|
| 2437 | * @offs: node offset
|
| 2438 | * @len: node length
|
| 2439 | * @hash: The hash over the node
|
| 2440 | * @nm: node name
|
| 2441 | *
|
| 2442 | * This is the same as 'ubifs_tnc_add()' but it should be used with keys which
|
| 2443 | * may have collisions, like directory entry keys.
|
| 2444 |
|
| 2445 | int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
|
| 2446 | int lnum, int offs, int len, const u8 *hash,
|
| 2447 | const struct fscrypt_name *nm)
|
| 2448 | {
|
| 2449 | int found, n, err = 0;
|
| 2450 | struct ubifs_znode *znode;
|
| 2451 |
|
| 2452 | mutex_lock(&c->tnc_mutex);
|
| 2453 | dbg_tnck(key, "LEB %d:%d, key ", lnum, offs);
|
| 2454 | found = lookup_level0_dirty(c, key, &znode, &n);
|
| 2455 | if (found < 0) {
|
| 2456 | err = found;
|
| 2457 | goto out_unlock;
|
| 2458 | }
|
| 2459 |
|
| 2460 | if (found == 1) {
|
| 2461 | if (c->replaying)
|
| 2462 | found = fallible_resolve_collision(c, key, &znode, &n,
|
| 2463 | nm, 1);
|
| 2464 | else
|
| 2465 | found = resolve_collision(c, key, &znode, &n, nm);
|
| 2466 | dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n);
|
| 2467 | if (found < 0) {
|
| 2468 | err = found;
|
| 2469 | goto out_unlock;
|
| 2470 | }
|
| 2471 |
|
| 2472 |
|
| 2473 | if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
| 2474 | znode = dirty_cow_bottom_up(c, znode);
|
| 2475 | if (IS_ERR(znode)) {
|
| 2476 | err = PTR_ERR(znode);
|
| 2477 | goto out_unlock;
|
| 2478 | }
|
| 2479 | }
|
| 2480 |
|
| 2481 | if (found == 1) {
|
| 2482 | struct ubifs_zbranch *zbr = &znode->zbranch[n];
|
| 2483 |
|
| 2484 | lnc_free(zbr);
|
| 2485 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
|
| 2486 | zbr->lnum = lnum;
|
| 2487 | zbr->offs = offs;
|
| 2488 | zbr->len = len;
|
| 2489 | ubifs_copy_hash(c, hash, zbr->hash);
|
| 2490 | goto out_unlock;
|
| 2491 | }
|
| 2492 | }
|
| 2493 |
|
| 2494 | if (!found) {
|
| 2495 | struct ubifs_zbranch zbr;
|
| 2496 |
|
| 2497 | zbr.znode = NULL;
|
| 2498 | zbr.lnum = lnum;
|
| 2499 | zbr.offs = offs;
|
| 2500 | zbr.len = len;
|
| 2501 | ubifs_copy_hash(c, hash, zbr.hash);
|
| 2502 | key_copy(c, key, &zbr.key);
|
| 2503 | err = tnc_insert(c, znode, &zbr, n + 1);
|
| 2504 | if (err)
|
| 2505 | goto out_unlock;
|
| 2506 | if (c->replaying) {
|
| 2507 | |
| 2508 | * We did not find it in the index so there may be a
|
| 2509 | * dangling branch still in the index. So we remove it
|
| 2510 | * by passing 'ubifs_tnc_remove_nm()' the same key but
|
| 2511 | * an unmatchable name.
|
| 2512 |
|
| 2513 | struct fscrypt_name noname = { .disk_name = { .name = "", .len = 1 } };
|
| 2514 |
|
| 2515 | err = dbg_check_tnc(c, 0);
|
| 2516 | mutex_unlock(&c->tnc_mutex);
|
| 2517 | if (err)
|
| 2518 | return err;
|
| 2519 | return ubifs_tnc_remove_nm(c, key, &noname);
|
| 2520 | }
|
| 2521 | }
|
| 2522 |
|
| 2523 | out_unlock:
|
| 2524 | if (!err)
|
| 2525 | err = dbg_check_tnc(c, 0);
|
| 2526 | mutex_unlock(&c->tnc_mutex);
|
| 2527 | return err;
|
| 2528 | }
|
| 2529 |
|
| 2530 | |
| 2531 | * tnc_delete - delete a znode form TNC.
|
| 2532 | * @c: UBIFS file-system description object
|
| 2533 | * @znode: znode to delete from
|
| 2534 | * @n: zbranch slot number to delete
|
| 2535 | *
|
| 2536 | * This function deletes a leaf node from @n-th slot of @znode. Returns zero in
|
| 2537 | * case of success and a negative error code in case of failure.
|
| 2538 |
|
| 2539 | static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n)
|
| 2540 | {
|
| 2541 | struct ubifs_zbranch *zbr;
|
| 2542 | struct ubifs_znode *zp;
|
| 2543 | int i, err;
|
| 2544 |
|
| 2545 |
|
| 2546 | ubifs_assert(c, znode->level == 0);
|
| 2547 | ubifs_assert(c, n >= 0 && n < c->fanout);
|
| 2548 | dbg_tnck(&znode->zbranch[n].key, "deleting key ");
|
| 2549 |
|
| 2550 | zbr = &znode->zbranch[n];
|
| 2551 | lnc_free(zbr);
|
| 2552 |
|
| 2553 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
|
| 2554 | if (err) {
|
| 2555 | ubifs_dump_znode(c, znode);
|
| 2556 | return err;
|
| 2557 | }
|
| 2558 |
|
| 2559 |
|
| 2560 | for (i = n; i < znode->child_cnt - 1; i++)
|
| 2561 | znode->zbranch[i] = znode->zbranch[i + 1];
|
| 2562 | znode->child_cnt -= 1;
|
| 2563 |
|
| 2564 | if (znode->child_cnt > 0)
|
| 2565 | return 0;
|
| 2566 |
|
| 2567 | |
| 2568 | * This was the last zbranch, we have to delete this znode from the
|
| 2569 | * parent.
|
| 2570 |
|
| 2571 |
|
| 2572 | do {
|
| 2573 | ubifs_assert(c, !ubifs_zn_obsolete(znode));
|
| 2574 | ubifs_assert(c, ubifs_zn_dirty(znode));
|
| 2575 |
|
| 2576 | zp = znode->parent;
|
| 2577 | n = znode->iip;
|
| 2578 |
|
| 2579 | atomic_long_dec(&c->dirty_zn_cnt);
|
| 2580 |
|
| 2581 | err = insert_old_idx_znode(c, znode);
|
| 2582 | if (err)
|
| 2583 | return err;
|
| 2584 |
|
| 2585 | if (znode->cnext) {
|
| 2586 | __set_bit(OBSOLETE_ZNODE, &znode->flags);
|
| 2587 | atomic_long_inc(&c->clean_zn_cnt);
|
| 2588 | atomic_long_inc(&ubifs_clean_zn_cnt);
|
| 2589 | } else
|
| 2590 | kfree(znode);
|
| 2591 | znode = zp;
|
| 2592 | } while (znode->child_cnt == 1);
|
| 2593 |
|
| 2594 |
|
| 2595 | znode->child_cnt -= 1;
|
| 2596 | ubifs_assert(c, znode->level != 0);
|
| 2597 | for (i = n; i < znode->child_cnt; i++) {
|
| 2598 | znode->zbranch[i] = znode->zbranch[i + 1];
|
| 2599 | if (znode->zbranch[i].znode)
|
| 2600 | znode->zbranch[i].znode->iip = i;
|
| 2601 | }
|
| 2602 |
|
| 2603 | |
| 2604 | * If this is the root and it has only 1 child then
|
| 2605 | * collapse the tree.
|
| 2606 |
|
| 2607 | if (!znode->parent) {
|
| 2608 | while (znode->child_cnt == 1 && znode->level != 0) {
|
| 2609 | zp = znode;
|
| 2610 | zbr = &znode->zbranch[0];
|
| 2611 | znode = get_znode(c, znode, 0);
|
| 2612 | if (IS_ERR(znode))
|
| 2613 | return PTR_ERR(znode);
|
| 2614 | znode = dirty_cow_znode(c, zbr);
|
| 2615 | if (IS_ERR(znode))
|
| 2616 | return PTR_ERR(znode);
|
| 2617 | znode->parent = NULL;
|
| 2618 | znode->iip = 0;
|
| 2619 | if (c->zroot.len) {
|
| 2620 | err = insert_old_idx(c, c->zroot.lnum,
|
| 2621 | c->zroot.offs);
|
| 2622 | if (err)
|
| 2623 | return err;
|
| 2624 | }
|
| 2625 | c->zroot.lnum = zbr->lnum;
|
| 2626 | c->zroot.offs = zbr->offs;
|
| 2627 | c->zroot.len = zbr->len;
|
| 2628 | c->zroot.znode = znode;
|
| 2629 | ubifs_assert(c, !ubifs_zn_obsolete(zp));
|
| 2630 | ubifs_assert(c, ubifs_zn_dirty(zp));
|
| 2631 | atomic_long_dec(&c->dirty_zn_cnt);
|
| 2632 |
|
| 2633 | if (zp->cnext) {
|
| 2634 | __set_bit(OBSOLETE_ZNODE, &zp->flags);
|
| 2635 | atomic_long_inc(&c->clean_zn_cnt);
|
| 2636 | atomic_long_inc(&ubifs_clean_zn_cnt);
|
| 2637 | } else
|
| 2638 | kfree(zp);
|
| 2639 | }
|
| 2640 | }
|
| 2641 |
|
| 2642 | return 0;
|
| 2643 | }
|
| 2644 |
|
| 2645 | |
| 2646 | * ubifs_tnc_remove - remove an index entry of a node.
|
| 2647 | * @c: UBIFS file-system description object
|
| 2648 | * @key: key of node
|
| 2649 | *
|
| 2650 | * Returns %0 on success or negative error code on failure.
|
| 2651 |
|
| 2652 | int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key)
|
| 2653 | {
|
| 2654 | int found, n, err = 0;
|
| 2655 | struct ubifs_znode *znode;
|
| 2656 |
|
| 2657 | mutex_lock(&c->tnc_mutex);
|
| 2658 | dbg_tnck(key, "key ");
|
| 2659 | found = lookup_level0_dirty(c, key, &znode, &n);
|
| 2660 | if (found < 0) {
|
| 2661 | err = found;
|
| 2662 | goto out_unlock;
|
| 2663 | }
|
| 2664 | if (found == 1)
|
| 2665 | err = tnc_delete(c, znode, n);
|
| 2666 | if (!err)
|
| 2667 | err = dbg_check_tnc(c, 0);
|
| 2668 |
|
| 2669 | out_unlock:
|
| 2670 | mutex_unlock(&c->tnc_mutex);
|
| 2671 | return err;
|
| 2672 | }
|
| 2673 |
|
| 2674 | |
| 2675 | * ubifs_tnc_remove_nm - remove an index entry for a "hashed" node.
|
| 2676 | * @c: UBIFS file-system description object
|
| 2677 | * @key: key of node
|
| 2678 | * @nm: directory entry name
|
| 2679 | *
|
| 2680 | * Returns %0 on success or negative error code on failure.
|
| 2681 |
|
| 2682 | int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
|
| 2683 | const struct fscrypt_name *nm)
|
| 2684 | {
|
| 2685 | int n, err;
|
| 2686 | struct ubifs_znode *znode;
|
| 2687 |
|
| 2688 | mutex_lock(&c->tnc_mutex);
|
| 2689 | dbg_tnck(key, "key ");
|
| 2690 | err = lookup_level0_dirty(c, key, &znode, &n);
|
| 2691 | if (err < 0)
|
| 2692 | goto out_unlock;
|
| 2693 |
|
| 2694 | if (err) {
|
| 2695 | if (c->replaying)
|
| 2696 | err = fallible_resolve_collision(c, key, &znode, &n,
|
| 2697 | nm, 0);
|
| 2698 | else
|
| 2699 | err = resolve_collision(c, key, &znode, &n, nm);
|
| 2700 | dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n);
|
| 2701 | if (err < 0)
|
| 2702 | goto out_unlock;
|
| 2703 | if (err) {
|
| 2704 |
|
| 2705 | if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
| 2706 | znode = dirty_cow_bottom_up(c, znode);
|
| 2707 | if (IS_ERR(znode)) {
|
| 2708 | err = PTR_ERR(znode);
|
| 2709 | goto out_unlock;
|
| 2710 | }
|
| 2711 | }
|
| 2712 | err = tnc_delete(c, znode, n);
|
| 2713 | }
|
| 2714 | }
|
| 2715 |
|
| 2716 | out_unlock:
|
| 2717 | if (!err)
|
| 2718 | err = dbg_check_tnc(c, 0);
|
| 2719 | mutex_unlock(&c->tnc_mutex);
|
| 2720 | return err;
|
| 2721 | }
|
| 2722 |
|
| 2723 | |
| 2724 | * ubifs_tnc_remove_dh - remove an index entry for a "double hashed" node.
|
| 2725 | * @c: UBIFS file-system description object
|
| 2726 | * @key: key of node
|
| 2727 | * @cookie: node cookie for collision resolution
|
| 2728 | *
|
| 2729 | * Returns %0 on success or negative error code on failure.
|
| 2730 |
|
| 2731 | int ubifs_tnc_remove_dh(struct ubifs_info *c, const union ubifs_key *key,
|
| 2732 | uint32_t cookie)
|
| 2733 | {
|
| 2734 | int n, err;
|
| 2735 | struct ubifs_znode *znode;
|
| 2736 | struct ubifs_dent_node *dent;
|
| 2737 | struct ubifs_zbranch *zbr;
|
| 2738 |
|
| 2739 | if (!c->double_hash)
|
| 2740 | return -EOPNOTSUPP;
|
| 2741 |
|
| 2742 | mutex_lock(&c->tnc_mutex);
|
| 2743 | err = lookup_level0_dirty(c, key, &znode, &n);
|
| 2744 | if (err <= 0)
|
| 2745 | goto out_unlock;
|
| 2746 |
|
| 2747 | zbr = &znode->zbranch[n];
|
| 2748 | dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
|
| 2749 | if (!dent) {
|
| 2750 | err = -ENOMEM;
|
| 2751 | goto out_unlock;
|
| 2752 | }
|
| 2753 |
|
| 2754 | err = tnc_read_hashed_node(c, zbr, dent);
|
| 2755 | if (err)
|
| 2756 | goto out_free;
|
| 2757 |
|
| 2758 |
|
| 2759 | if (le32_to_cpu(dent->cookie) != cookie) {
|
| 2760 | union ubifs_key start_key;
|
| 2761 |
|
| 2762 | lowest_dent_key(c, &start_key, key_inum(c, key));
|
| 2763 |
|
| 2764 | err = ubifs_lookup_level0(c, &start_key, &znode, &n);
|
| 2765 | if (unlikely(err < 0))
|
| 2766 | goto out_free;
|
| 2767 |
|
| 2768 | err = search_dh_cookie(c, key, dent, cookie, &znode, &n, err);
|
| 2769 | if (err)
|
| 2770 | goto out_free;
|
| 2771 | }
|
| 2772 |
|
| 2773 | if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
| 2774 | znode = dirty_cow_bottom_up(c, znode);
|
| 2775 | if (IS_ERR(znode)) {
|
| 2776 | err = PTR_ERR(znode);
|
| 2777 | goto out_free;
|
| 2778 | }
|
| 2779 | }
|
| 2780 | err = tnc_delete(c, znode, n);
|
| 2781 |
|
| 2782 | out_free:
|
| 2783 | kfree(dent);
|
| 2784 | out_unlock:
|
| 2785 | if (!err)
|
| 2786 | err = dbg_check_tnc(c, 0);
|
| 2787 | mutex_unlock(&c->tnc_mutex);
|
| 2788 | return err;
|
| 2789 | }
|
| 2790 |
|
| 2791 | |
| 2792 | * key_in_range - determine if a key falls within a range of keys.
|
| 2793 | * @c: UBIFS file-system description object
|
| 2794 | * @key: key to check
|
| 2795 | * @from_key: lowest key in range
|
| 2796 | * @to_key: highest key in range
|
| 2797 | *
|
| 2798 | * This function returns %1 if the key is in range and %0 otherwise.
|
| 2799 |
|
| 2800 | static int key_in_range(struct ubifs_info *c, union ubifs_key *key,
|
| 2801 | union ubifs_key *from_key, union ubifs_key *to_key)
|
| 2802 | {
|
| 2803 | if (keys_cmp(c, key, from_key) < 0)
|
| 2804 | return 0;
|
| 2805 | if (keys_cmp(c, key, to_key) > 0)
|
| 2806 | return 0;
|
| 2807 | return 1;
|
| 2808 | }
|
| 2809 |
|
| 2810 | |
| 2811 | * ubifs_tnc_remove_range - remove index entries in range.
|
| 2812 | * @c: UBIFS file-system description object
|
| 2813 | * @from_key: lowest key to remove
|
| 2814 | * @to_key: highest key to remove
|
| 2815 | *
|
| 2816 | * This function removes index entries starting at @from_key and ending at
|
| 2817 | * @to_key. This function returns zero in case of success and a negative error
|
| 2818 | * code in case of failure.
|
| 2819 |
|
| 2820 | int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key,
|
| 2821 | union ubifs_key *to_key)
|
| 2822 | {
|
| 2823 | int i, n, k, err = 0;
|
| 2824 | struct ubifs_znode *znode;
|
| 2825 | union ubifs_key *key;
|
| 2826 |
|
| 2827 | mutex_lock(&c->tnc_mutex);
|
| 2828 | while (1) {
|
| 2829 |
|
| 2830 | err = ubifs_lookup_level0(c, from_key, &znode, &n);
|
| 2831 | if (err < 0)
|
| 2832 | goto out_unlock;
|
| 2833 |
|
| 2834 | if (err)
|
| 2835 | key = from_key;
|
| 2836 | else {
|
| 2837 | err = tnc_next(c, &znode, &n);
|
| 2838 | if (err == -ENOENT) {
|
| 2839 | err = 0;
|
| 2840 | goto out_unlock;
|
| 2841 | }
|
| 2842 | if (err < 0)
|
| 2843 | goto out_unlock;
|
| 2844 | key = &znode->zbranch[n].key;
|
| 2845 | if (!key_in_range(c, key, from_key, to_key)) {
|
| 2846 | err = 0;
|
| 2847 | goto out_unlock;
|
| 2848 | }
|
| 2849 | }
|
| 2850 |
|
| 2851 |
|
| 2852 | if (znode->cnext || !ubifs_zn_dirty(znode)) {
|
| 2853 | znode = dirty_cow_bottom_up(c, znode);
|
| 2854 | if (IS_ERR(znode)) {
|
| 2855 | err = PTR_ERR(znode);
|
| 2856 | goto out_unlock;
|
| 2857 | }
|
| 2858 | }
|
| 2859 |
|
| 2860 |
|
| 2861 | for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) {
|
| 2862 | key = &znode->zbranch[i].key;
|
| 2863 | if (!key_in_range(c, key, from_key, to_key))
|
| 2864 | break;
|
| 2865 | lnc_free(&znode->zbranch[i]);
|
| 2866 | err = ubifs_add_dirt(c, znode->zbranch[i].lnum,
|
| 2867 | znode->zbranch[i].len);
|
| 2868 | if (err) {
|
| 2869 | ubifs_dump_znode(c, znode);
|
| 2870 | goto out_unlock;
|
| 2871 | }
|
| 2872 | dbg_tnck(key, "removing key ");
|
| 2873 | }
|
| 2874 | if (k) {
|
| 2875 | for (i = n + 1 + k; i < znode->child_cnt; i++)
|
| 2876 | znode->zbranch[i - k] = znode->zbranch[i];
|
| 2877 | znode->child_cnt -= k;
|
| 2878 | }
|
| 2879 |
|
| 2880 |
|
| 2881 | err = tnc_delete(c, znode, n);
|
| 2882 | if (err)
|
| 2883 | goto out_unlock;
|
| 2884 | }
|
| 2885 |
|
| 2886 | out_unlock:
|
| 2887 | if (!err)
|
| 2888 | err = dbg_check_tnc(c, 0);
|
| 2889 | mutex_unlock(&c->tnc_mutex);
|
| 2890 | return err;
|
| 2891 | }
|
| 2892 |
|
| 2893 | |
| 2894 | * ubifs_tnc_remove_ino - remove an inode from TNC.
|
| 2895 | * @c: UBIFS file-system description object
|
| 2896 | * @inum: inode number to remove
|
| 2897 | *
|
| 2898 | * This function remove inode @inum and all the extended attributes associated
|
| 2899 | * with the anode from TNC and returns zero in case of success or a negative
|
| 2900 | * error code in case of failure.
|
| 2901 |
|
| 2902 | int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
|
| 2903 | {
|
| 2904 | union ubifs_key key1, key2;
|
| 2905 | struct ubifs_dent_node *xent, *pxent = NULL;
|
| 2906 | struct fscrypt_name nm = {0};
|
| 2907 |
|
| 2908 | dbg_tnc("ino %lu", (unsigned long)inum);
|
| 2909 |
|
| 2910 | |
| 2911 | * Walk all extended attribute entries and remove them together with
|
| 2912 | * corresponding extended attribute inodes.
|
| 2913 |
|
| 2914 | lowest_xent_key(c, &key1, inum);
|
| 2915 | while (1) {
|
| 2916 | ino_t xattr_inum;
|
| 2917 | int err;
|
| 2918 |
|
| 2919 | xent = ubifs_tnc_next_ent(c, &key1, &nm);
|
| 2920 | if (IS_ERR(xent)) {
|
| 2921 | err = PTR_ERR(xent);
|
| 2922 | if (err == -ENOENT)
|
| 2923 | break;
|
| 2924 | kfree(pxent);
|
| 2925 | return err;
|
| 2926 | }
|
| 2927 |
|
| 2928 | xattr_inum = le64_to_cpu(xent->inum);
|
| 2929 | dbg_tnc("xent '%s', ino %lu", xent->name,
|
| 2930 | (unsigned long)xattr_inum);
|
| 2931 |
|
| 2932 | fname_name(&nm) = xent->name;
|
| 2933 | fname_len(&nm) = le16_to_cpu(xent->nlen);
|
| 2934 | err = ubifs_tnc_remove_nm(c, &key1, &nm);
|
| 2935 | if (err) {
|
| 2936 | kfree(pxent);
|
| 2937 | kfree(xent);
|
| 2938 | return err;
|
| 2939 | }
|
| 2940 |
|
| 2941 | lowest_ino_key(c, &key1, xattr_inum);
|
| 2942 | highest_ino_key(c, &key2, xattr_inum);
|
| 2943 | err = ubifs_tnc_remove_range(c, &key1, &key2);
|
| 2944 | if (err) {
|
| 2945 | kfree(pxent);
|
| 2946 | kfree(xent);
|
| 2947 | return err;
|
| 2948 | }
|
| 2949 |
|
| 2950 | kfree(pxent);
|
| 2951 | pxent = xent;
|
| 2952 | key_read(c, &xent->key, &key1);
|
| 2953 | }
|
| 2954 |
|
| 2955 | kfree(pxent);
|
| 2956 | lowest_ino_key(c, &key1, inum);
|
| 2957 | highest_ino_key(c, &key2, inum);
|
| 2958 |
|
| 2959 | return ubifs_tnc_remove_range(c, &key1, &key2);
|
| 2960 | }
|
| 2961 |
|
| 2962 | |
| 2963 | * ubifs_tnc_next_ent - walk directory or extended attribute entries.
|
| 2964 | * @c: UBIFS file-system description object
|
| 2965 | * @key: key of last entry
|
| 2966 | * @nm: name of last entry found or %NULL
|
| 2967 | *
|
| 2968 | * This function finds and reads the next directory or extended attribute entry
|
| 2969 | * after the given key (@key) if there is one. @nm is used to resolve
|
| 2970 | * collisions.
|
| 2971 | *
|
| 2972 | * If the name of the current entry is not known and only the key is known,
|
| 2973 | * @nm->name has to be %NULL. In this case the semantics of this function is a
|
| 2974 | * little bit different and it returns the entry corresponding to this key, not
|
| 2975 | * the next one. If the key was not found, the closest "right" entry is
|
| 2976 | * returned.
|
| 2977 | *
|
| 2978 | * If the fist entry has to be found, @key has to contain the lowest possible
|
| 2979 | * key value for this inode and @name has to be %NULL.
|
| 2980 | *
|
| 2981 | * This function returns the found directory or extended attribute entry node
|
| 2982 | * in case of success, %-ENOENT is returned if no entry was found, and a
|
| 2983 | * negative error code is returned in case of failure.
|
| 2984 |
|
| 2985 | struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c,
|
| 2986 | union ubifs_key *key,
|
| 2987 | const struct fscrypt_name *nm)
|
| 2988 | {
|
| 2989 | int n, err, type = key_type(c, key);
|
| 2990 | struct ubifs_znode *znode;
|
| 2991 | struct ubifs_dent_node *dent;
|
| 2992 | struct ubifs_zbranch *zbr;
|
| 2993 | union ubifs_key *dkey;
|
| 2994 |
|
| 2995 | dbg_tnck(key, "key ");
|
| 2996 | ubifs_assert(c, is_hash_key(c, key));
|
| 2997 |
|
| 2998 | mutex_lock(&c->tnc_mutex);
|
| 2999 | err = ubifs_lookup_level0(c, key, &znode, &n);
|
| 3000 | if (unlikely(err < 0))
|
| 3001 | goto out_unlock;
|
| 3002 |
|
| 3003 | if (fname_len(nm) > 0) {
|
| 3004 | if (err) {
|
| 3005 |
|
| 3006 | if (c->replaying)
|
| 3007 | err = fallible_resolve_collision(c, key, &znode, &n,
|
| 3008 | nm, 0);
|
| 3009 | else
|
| 3010 | err = resolve_collision(c, key, &znode, &n, nm);
|
| 3011 | dbg_tnc("rc returned %d, znode %p, n %d",
|
| 3012 | err, znode, n);
|
| 3013 | if (unlikely(err < 0))
|
| 3014 | goto out_unlock;
|
| 3015 | }
|
| 3016 |
|
| 3017 |
|
| 3018 | err = tnc_next(c, &znode, &n);
|
| 3019 | if (unlikely(err))
|
| 3020 | goto out_unlock;
|
| 3021 | } else {
|
| 3022 | |
| 3023 | * The full name of the entry was not given, in which case the
|
| 3024 | * behavior of this function is a little different and it
|
| 3025 | * returns current entry, not the next one.
|
| 3026 |
|
| 3027 | if (!err) {
|
| 3028 | |
| 3029 | * However, the given key does not exist in the TNC
|
| 3030 | * tree and @znode/@n variables contain the closest
|
| 3031 | * "preceding" element. Switch to the next one.
|
| 3032 |
|
| 3033 | err = tnc_next(c, &znode, &n);
|
| 3034 | if (err)
|
| 3035 | goto out_unlock;
|
| 3036 | }
|
| 3037 | }
|
| 3038 |
|
| 3039 | zbr = &znode->zbranch[n];
|
| 3040 | dent = kmalloc(zbr->len, GFP_NOFS);
|
| 3041 | if (unlikely(!dent)) {
|
| 3042 | err = -ENOMEM;
|
| 3043 | goto out_unlock;
|
| 3044 | }
|
| 3045 |
|
| 3046 | |
| 3047 | * The above 'tnc_next()' call could lead us to the next inode, check
|
| 3048 | * this.
|
| 3049 |
|
| 3050 | dkey = &zbr->key;
|
| 3051 | if (key_inum(c, dkey) != key_inum(c, key) ||
|
| 3052 | key_type(c, dkey) != type) {
|
| 3053 | err = -ENOENT;
|
| 3054 | goto out_free;
|
| 3055 | }
|
| 3056 |
|
| 3057 | err = tnc_read_hashed_node(c, zbr, dent);
|
| 3058 | if (unlikely(err))
|
| 3059 | goto out_free;
|
| 3060 |
|
| 3061 | mutex_unlock(&c->tnc_mutex);
|
| 3062 | return dent;
|
| 3063 |
|
| 3064 | out_free:
|
| 3065 | kfree(dent);
|
| 3066 | out_unlock:
|
| 3067 | mutex_unlock(&c->tnc_mutex);
|
| 3068 | return ERR_PTR(err);
|
| 3069 | }
|
| 3070 |
|
| 3071 | |
| 3072 | * tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit.
|
| 3073 | * @c: UBIFS file-system description object
|
| 3074 | *
|
| 3075 | * Destroy left-over obsolete znodes from a failed commit.
|
| 3076 |
|
| 3077 | static void tnc_destroy_cnext(struct ubifs_info *c)
|
| 3078 | {
|
| 3079 | struct ubifs_znode *cnext;
|
| 3080 |
|
| 3081 | if (!c->cnext)
|
| 3082 | return;
|
| 3083 | ubifs_assert(c, c->cmt_state == COMMIT_BROKEN);
|
| 3084 | cnext = c->cnext;
|
| 3085 | do {
|
| 3086 | struct ubifs_znode *znode = cnext;
|
| 3087 |
|
| 3088 | cnext = cnext->cnext;
|
| 3089 | if (ubifs_zn_obsolete(znode))
|
| 3090 | kfree(znode);
|
| 3091 | else if (!ubifs_zn_cow(znode)) {
|
| 3092 | |
| 3093 | * Don't forget to update clean znode count after
|
| 3094 | * committing failed, because ubifs will check this
|
| 3095 | * count while closing tnc. Non-obsolete znode could
|
| 3096 | * be re-dirtied during committing process, so dirty
|
| 3097 | * flag is untrustable. The flag 'COW_ZNODE' is set
|
| 3098 | * for each dirty znode before committing, and it is
|
| 3099 | * cleared as long as the znode become clean, so we
|
| 3100 | * can statistic clean znode count according to this
|
| 3101 | * flag.
|
| 3102 |
|
| 3103 | atomic_long_inc(&c->clean_zn_cnt);
|
| 3104 | atomic_long_inc(&ubifs_clean_zn_cnt);
|
| 3105 | }
|
| 3106 | } while (cnext && cnext != c->cnext);
|
| 3107 | }
|
| 3108 |
|
| 3109 | |
| 3110 | * ubifs_tnc_close - close TNC subsystem and free all related resources.
|
| 3111 | * @c: UBIFS file-system description object
|
| 3112 |
|
| 3113 | void ubifs_tnc_close(struct ubifs_info *c)
|
| 3114 | {
|
| 3115 | tnc_destroy_cnext(c);
|
| 3116 | ubifs_destroy_tnc_tree(c);
|
| 3117 | kfree(c->gap_lebs);
|
| 3118 | kfree(c->ilebs);
|
| 3119 | destroy_old_idx(c);
|
| 3120 | }
|
| 3121 |
|
| 3122 | |
| 3123 | * left_znode - get the znode to the left.
|
| 3124 | * @c: UBIFS file-system description object
|
| 3125 | * @znode: znode
|
| 3126 | *
|
| 3127 | * This function returns a pointer to the znode to the left of @znode or NULL if
|
| 3128 | * there is not one. A negative error code is returned on failure.
|
| 3129 |
|
| 3130 | static struct ubifs_znode *left_znode(struct ubifs_info *c,
|
| 3131 | struct ubifs_znode *znode)
|
| 3132 | {
|
| 3133 | int level = znode->level;
|
| 3134 |
|
| 3135 | while (1) {
|
| 3136 | int n = znode->iip - 1;
|
| 3137 |
|
| 3138 |
|
| 3139 | znode = znode->parent;
|
| 3140 | if (!znode)
|
| 3141 | return NULL;
|
| 3142 | if (n >= 0) {
|
| 3143 |
|
| 3144 | znode = get_znode(c, znode, n);
|
| 3145 | if (IS_ERR(znode))
|
| 3146 | return znode;
|
| 3147 | while (znode->level != level) {
|
| 3148 | n = znode->child_cnt - 1;
|
| 3149 | znode = get_znode(c, znode, n);
|
| 3150 | if (IS_ERR(znode))
|
| 3151 | return znode;
|
| 3152 | }
|
| 3153 | break;
|
| 3154 | }
|
| 3155 | }
|
| 3156 | return znode;
|
| 3157 | }
|
| 3158 |
|
| 3159 | |
| 3160 | * right_znode - get the znode to the right.
|
| 3161 | * @c: UBIFS file-system description object
|
| 3162 | * @znode: znode
|
| 3163 | *
|
| 3164 | * This function returns a pointer to the znode to the right of @znode or NULL
|
| 3165 | * if there is not one. A negative error code is returned on failure.
|
| 3166 |
|
| 3167 | static struct ubifs_znode *right_znode(struct ubifs_info *c,
|
| 3168 | struct ubifs_znode *znode)
|
| 3169 | {
|
| 3170 | int level = znode->level;
|
| 3171 |
|
| 3172 | while (1) {
|
| 3173 | int n = znode->iip + 1;
|
| 3174 |
|
| 3175 |
|
| 3176 | znode = znode->parent;
|
| 3177 | if (!znode)
|
| 3178 | return NULL;
|
| 3179 | if (n < znode->child_cnt) {
|
| 3180 |
|
| 3181 | znode = get_znode(c, znode, n);
|
| 3182 | if (IS_ERR(znode))
|
| 3183 | return znode;
|
| 3184 | while (znode->level != level) {
|
| 3185 | znode = get_znode(c, znode, 0);
|
| 3186 | if (IS_ERR(znode))
|
| 3187 | return znode;
|
| 3188 | }
|
| 3189 | break;
|
| 3190 | }
|
| 3191 | }
|
| 3192 | return znode;
|
| 3193 | }
|
| 3194 |
|
| 3195 | |
| 3196 | * lookup_znode - find a particular indexing node from TNC.
|
| 3197 | * @c: UBIFS file-system description object
|
| 3198 | * @key: index node key to lookup
|
| 3199 | * @level: index node level
|
| 3200 | * @lnum: index node LEB number
|
| 3201 | * @offs: index node offset
|
| 3202 | *
|
| 3203 | * This function searches an indexing node by its first key @key and its
|
| 3204 | * address @lnum:@offs. It looks up the indexing tree by pulling all indexing
|
| 3205 | * nodes it traverses to TNC. This function is called for indexing nodes which
|
| 3206 | * were found on the media by scanning, for example when garbage-collecting or
|
| 3207 | * when doing in-the-gaps commit. This means that the indexing node which is
|
| 3208 | * looked for does not have to have exactly the same leftmost key @key, because
|
| 3209 | * the leftmost key may have been changed, in which case TNC will contain a
|
| 3210 | * dirty znode which still refers the same @lnum:@offs. This function is clever
|
| 3211 | * enough to recognize such indexing nodes.
|
| 3212 | *
|
| 3213 | * Note, if a znode was deleted or changed too much, then this function will
|
| 3214 | * not find it. For situations like this UBIFS has the old index RB-tree
|
| 3215 | * (indexed by @lnum:@offs).
|
| 3216 | *
|
| 3217 | * This function returns a pointer to the znode found or %NULL if it is not
|
| 3218 | * found. A negative error code is returned on failure.
|
| 3219 |
|
| 3220 | static struct ubifs_znode *lookup_znode(struct ubifs_info *c,
|
| 3221 | union ubifs_key *key, int level,
|
| 3222 | int lnum, int offs)
|
| 3223 | {
|
| 3224 | struct ubifs_znode *znode, *zn;
|
| 3225 | int n, nn;
|
| 3226 |
|
| 3227 | ubifs_assert(c, key_type(c, key) < UBIFS_INVALID_KEY);
|
| 3228 |
|
| 3229 | |
| 3230 | * The arguments have probably been read off flash, so don't assume
|
| 3231 | * they are valid.
|
| 3232 |
|
| 3233 | if (level < 0)
|
| 3234 | return ERR_PTR(-EINVAL);
|
| 3235 |
|
| 3236 |
|
| 3237 | znode = c->zroot.znode;
|
| 3238 | if (!znode) {
|
| 3239 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
|
| 3240 | if (IS_ERR(znode))
|
| 3241 | return znode;
|
| 3242 | }
|
| 3243 |
|
| 3244 | if (c->zroot.lnum == lnum && c->zroot.offs == offs)
|
| 3245 | return znode;
|
| 3246 |
|
| 3247 | if (level >= znode->level)
|
| 3248 | return NULL;
|
| 3249 | while (1) {
|
| 3250 | ubifs_search_zbranch(c, znode, key, &n);
|
| 3251 | if (n < 0) {
|
| 3252 | |
| 3253 | * We reached a znode where the leftmost key is greater
|
| 3254 | * than the key we are searching for. This is the same
|
| 3255 | * situation as the one described in a huge comment at
|
| 3256 | * the end of the 'ubifs_lookup_level0()' function. And
|
| 3257 | * for exactly the same reasons we have to try to look
|
| 3258 | * left before giving up.
|
| 3259 |
|
| 3260 | znode = left_znode(c, znode);
|
| 3261 | if (!znode)
|
| 3262 | return NULL;
|
| 3263 | if (IS_ERR(znode))
|
| 3264 | return znode;
|
| 3265 | ubifs_search_zbranch(c, znode, key, &n);
|
| 3266 | ubifs_assert(c, n >= 0);
|
| 3267 | }
|
| 3268 | if (znode->level == level + 1)
|
| 3269 | break;
|
| 3270 | znode = get_znode(c, znode, n);
|
| 3271 | if (IS_ERR(znode))
|
| 3272 | return znode;
|
| 3273 | }
|
| 3274 |
|
| 3275 | if (znode->zbranch[n].lnum == lnum && znode->zbranch[n].offs == offs)
|
| 3276 | return get_znode(c, znode, n);
|
| 3277 |
|
| 3278 | if (!is_hash_key(c, key))
|
| 3279 | return NULL;
|
| 3280 | |
| 3281 | * The key is not unique and so may be also in the znodes to either
|
| 3282 | * side.
|
| 3283 |
|
| 3284 | zn = znode;
|
| 3285 | nn = n;
|
| 3286 |
|
| 3287 | while (1) {
|
| 3288 |
|
| 3289 | if (n)
|
| 3290 | n -= 1;
|
| 3291 | else {
|
| 3292 | znode = left_znode(c, znode);
|
| 3293 | if (!znode)
|
| 3294 | break;
|
| 3295 | if (IS_ERR(znode))
|
| 3296 | return znode;
|
| 3297 | n = znode->child_cnt - 1;
|
| 3298 | }
|
| 3299 |
|
| 3300 | if (znode->zbranch[n].lnum == lnum &&
|
| 3301 | znode->zbranch[n].offs == offs)
|
| 3302 | return get_znode(c, znode, n);
|
| 3303 |
|
| 3304 | if (keys_cmp(c, &znode->zbranch[n].key, key) < 0)
|
| 3305 | break;
|
| 3306 | }
|
| 3307 |
|
| 3308 | znode = zn;
|
| 3309 | n = nn;
|
| 3310 |
|
| 3311 | while (1) {
|
| 3312 |
|
| 3313 | if (++n >= znode->child_cnt) {
|
| 3314 | znode = right_znode(c, znode);
|
| 3315 | if (!znode)
|
| 3316 | break;
|
| 3317 | if (IS_ERR(znode))
|
| 3318 | return znode;
|
| 3319 | n = 0;
|
| 3320 | }
|
| 3321 |
|
| 3322 | if (znode->zbranch[n].lnum == lnum &&
|
| 3323 | znode->zbranch[n].offs == offs)
|
| 3324 | return get_znode(c, znode, n);
|
| 3325 |
|
| 3326 | if (keys_cmp(c, &znode->zbranch[n].key, key) > 0)
|
| 3327 | break;
|
| 3328 | }
|
| 3329 | return NULL;
|
| 3330 | }
|
| 3331 |
|
| 3332 | |
| 3333 | * is_idx_node_in_tnc - determine if an index node is in the TNC.
|
| 3334 | * @c: UBIFS file-system description object
|
| 3335 | * @key: key of index node
|
| 3336 | * @level: index node level
|
| 3337 | * @lnum: LEB number of index node
|
| 3338 | * @offs: offset of index node
|
| 3339 | *
|
| 3340 | * This function returns %0 if the index node is not referred to in the TNC, %1
|
| 3341 | * if the index node is referred to in the TNC and the corresponding znode is
|
| 3342 | * dirty, %2 if an index node is referred to in the TNC and the corresponding
|
| 3343 | * znode is clean, and a negative error code in case of failure.
|
| 3344 | *
|
| 3345 | * Note, the @key argument has to be the key of the first child. Also note,
|
| 3346 | * this function relies on the fact that 0:0 is never a valid LEB number and
|
| 3347 | * offset for a main-area node.
|
| 3348 |
|
| 3349 | int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level,
|
| 3350 | int lnum, int offs)
|
| 3351 | {
|
| 3352 | struct ubifs_znode *znode;
|
| 3353 |
|
| 3354 | znode = lookup_znode(c, key, level, lnum, offs);
|
| 3355 | if (!znode)
|
| 3356 | return 0;
|
| 3357 | if (IS_ERR(znode))
|
| 3358 | return PTR_ERR(znode);
|
| 3359 |
|
| 3360 | return ubifs_zn_dirty(znode) ? 1 : 2;
|
| 3361 | }
|
| 3362 |
|
| 3363 | |
| 3364 | * is_leaf_node_in_tnc - determine if a non-indexing not is in the TNC.
|
| 3365 | * @c: UBIFS file-system description object
|
| 3366 | * @key: node key
|
| 3367 | * @lnum: node LEB number
|
| 3368 | * @offs: node offset
|
| 3369 | *
|
| 3370 | * This function returns %1 if the node is referred to in the TNC, %0 if it is
|
| 3371 | * not, and a negative error code in case of failure.
|
| 3372 | *
|
| 3373 | * Note, this function relies on the fact that 0:0 is never a valid LEB number
|
| 3374 | * and offset for a main-area node.
|
| 3375 |
|
| 3376 | static int is_leaf_node_in_tnc(struct ubifs_info *c, union ubifs_key *key,
|
| 3377 | int lnum, int offs)
|
| 3378 | {
|
| 3379 | struct ubifs_zbranch *zbr;
|
| 3380 | struct ubifs_znode *znode, *zn;
|
| 3381 | int n, found, err, nn;
|
| 3382 | const int unique = !is_hash_key(c, key);
|
| 3383 |
|
| 3384 | found = ubifs_lookup_level0(c, key, &znode, &n);
|
| 3385 | if (found < 0)
|
| 3386 | return found;
|
| 3387 | if (!found)
|
| 3388 | return 0;
|
| 3389 | zbr = &znode->zbranch[n];
|
| 3390 | if (lnum == zbr->lnum && offs == zbr->offs)
|
| 3391 | return 1;
|
| 3392 | if (unique)
|
| 3393 | return 0;
|
| 3394 | |
| 3395 | * Because the key is not unique, we have to look left
|
| 3396 | * and right as well
|
| 3397 |
|
| 3398 | zn = znode;
|
| 3399 | nn = n;
|
| 3400 |
|
| 3401 | while (1) {
|
| 3402 | err = tnc_prev(c, &znode, &n);
|
| 3403 | if (err == -ENOENT)
|
| 3404 | break;
|
| 3405 | if (err)
|
| 3406 | return err;
|
| 3407 | if (keys_cmp(c, key, &znode->zbranch[n].key))
|
| 3408 | break;
|
| 3409 | zbr = &znode->zbranch[n];
|
| 3410 | if (lnum == zbr->lnum && offs == zbr->offs)
|
| 3411 | return 1;
|
| 3412 | }
|
| 3413 |
|
| 3414 | znode = zn;
|
| 3415 | n = nn;
|
| 3416 | while (1) {
|
| 3417 | err = tnc_next(c, &znode, &n);
|
| 3418 | if (err) {
|
| 3419 | if (err == -ENOENT)
|
| 3420 | return 0;
|
| 3421 | return err;
|
| 3422 | }
|
| 3423 | if (keys_cmp(c, key, &znode->zbranch[n].key))
|
| 3424 | break;
|
| 3425 | zbr = &znode->zbranch[n];
|
| 3426 | if (lnum == zbr->lnum && offs == zbr->offs)
|
| 3427 | return 1;
|
| 3428 | }
|
| 3429 | return 0;
|
| 3430 | }
|
| 3431 |
|
| 3432 | |
| 3433 | * ubifs_tnc_has_node - determine whether a node is in the TNC.
|
| 3434 | * @c: UBIFS file-system description object
|
| 3435 | * @key: node key
|
| 3436 | * @level: index node level (if it is an index node)
|
| 3437 | * @lnum: node LEB number
|
| 3438 | * @offs: node offset
|
| 3439 | * @is_idx: non-zero if the node is an index node
|
| 3440 | *
|
| 3441 | * This function returns %1 if the node is in the TNC, %0 if it is not, and a
|
| 3442 | * negative error code in case of failure. For index nodes, @key has to be the
|
| 3443 | * key of the first child. An index node is considered to be in the TNC only if
|
| 3444 | * the corresponding znode is clean or has not been loaded.
|
| 3445 |
|
| 3446 | int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level,
|
| 3447 | int lnum, int offs, int is_idx)
|
| 3448 | {
|
| 3449 | int err;
|
| 3450 |
|
| 3451 | mutex_lock(&c->tnc_mutex);
|
| 3452 | if (is_idx) {
|
| 3453 | err = is_idx_node_in_tnc(c, key, level, lnum, offs);
|
| 3454 | if (err < 0)
|
| 3455 | goto out_unlock;
|
| 3456 | if (err == 1)
|
| 3457 |
|
| 3458 | err = 0;
|
| 3459 | else if (err == 2)
|
| 3460 |
|
| 3461 | err = 1;
|
| 3462 | else
|
| 3463 | BUG_ON(err != 0);
|
| 3464 | } else
|
| 3465 | err = is_leaf_node_in_tnc(c, key, lnum, offs);
|
| 3466 |
|
| 3467 | out_unlock:
|
| 3468 | mutex_unlock(&c->tnc_mutex);
|
| 3469 | return err;
|
| 3470 | }
|
| 3471 |
|
| 3472 | |
| 3473 | * ubifs_dirty_idx_node - dirty an index node.
|
| 3474 | * @c: UBIFS file-system description object
|
| 3475 | * @key: index node key
|
| 3476 | * @level: index node level
|
| 3477 | * @lnum: index node LEB number
|
| 3478 | * @offs: index node offset
|
| 3479 | *
|
| 3480 | * This function loads and dirties an index node so that it can be garbage
|
| 3481 | * collected. The @key argument has to be the key of the first child. This
|
| 3482 | * function relies on the fact that 0:0 is never a valid LEB number and offset
|
| 3483 | * for a main-area node. Returns %0 on success and a negative error code on
|
| 3484 | * failure.
|
| 3485 |
|
| 3486 | int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level,
|
| 3487 | int lnum, int offs)
|
| 3488 | {
|
| 3489 | struct ubifs_znode *znode;
|
| 3490 | int err = 0;
|
| 3491 |
|
| 3492 | mutex_lock(&c->tnc_mutex);
|
| 3493 | znode = lookup_znode(c, key, level, lnum, offs);
|
| 3494 | if (!znode)
|
| 3495 | goto out_unlock;
|
| 3496 | if (IS_ERR(znode)) {
|
| 3497 | err = PTR_ERR(znode);
|
| 3498 | goto out_unlock;
|
| 3499 | }
|
| 3500 | znode = dirty_cow_bottom_up(c, znode);
|
| 3501 | if (IS_ERR(znode)) {
|
| 3502 | err = PTR_ERR(znode);
|
| 3503 | goto out_unlock;
|
| 3504 | }
|
| 3505 |
|
| 3506 | out_unlock:
|
| 3507 | mutex_unlock(&c->tnc_mutex);
|
| 3508 | return err;
|
| 3509 | }
|
| 3510 |
|
| 3511 | |
| 3512 | * dbg_check_inode_size - check if inode size is correct.
|
| 3513 | * @c: UBIFS file-system description object
|
| 3514 | * @inode: inode to check
|
| 3515 | * @size: inode size
|
| 3516 | *
|
| 3517 | * This function makes sure that the inode size (@size) is correct and it does
|
| 3518 | * not have any pages beyond @size. Returns zero if the inode is OK, %-EINVAL
|
| 3519 | * if it has a data page beyond @size, and other negative error code in case of
|
| 3520 | * other errors.
|
| 3521 |
|
| 3522 | int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode,
|
| 3523 | loff_t size)
|
| 3524 | {
|
| 3525 | int err, n;
|
| 3526 | union ubifs_key from_key, to_key, *key;
|
| 3527 | struct ubifs_znode *znode;
|
| 3528 | unsigned int block;
|
| 3529 |
|
| 3530 | if (!S_ISREG(inode->i_mode))
|
| 3531 | return 0;
|
| 3532 | if (!dbg_is_chk_gen(c))
|
| 3533 | return 0;
|
| 3534 |
|
| 3535 | block = (size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
|
| 3536 | data_key_init(c, &from_key, inode->i_ino, block);
|
| 3537 | highest_data_key(c, &to_key, inode->i_ino);
|
| 3538 |
|
| 3539 | mutex_lock(&c->tnc_mutex);
|
| 3540 | err = ubifs_lookup_level0(c, &from_key, &znode, &n);
|
| 3541 | if (err < 0)
|
| 3542 | goto out_unlock;
|
| 3543 |
|
| 3544 | if (err) {
|
| 3545 | key = &from_key;
|
| 3546 | goto out_dump;
|
| 3547 | }
|
| 3548 |
|
| 3549 | err = tnc_next(c, &znode, &n);
|
| 3550 | if (err == -ENOENT) {
|
| 3551 | err = 0;
|
| 3552 | goto out_unlock;
|
| 3553 | }
|
| 3554 | if (err < 0)
|
| 3555 | goto out_unlock;
|
| 3556 |
|
| 3557 | ubifs_assert(c, err == 0);
|
| 3558 | key = &znode->zbranch[n].key;
|
| 3559 | if (!key_in_range(c, key, &from_key, &to_key))
|
| 3560 | goto out_unlock;
|
| 3561 |
|
| 3562 | out_dump:
|
| 3563 | block = key_block(c, key);
|
| 3564 | ubifs_err(c, "inode %llu has size %lld, but there are data at offset %lld",
|
| 3565 | inode->i_ino, size,
|
| 3566 | ((loff_t)block) << UBIFS_BLOCK_SHIFT);
|
| 3567 | mutex_unlock(&c->tnc_mutex);
|
| 3568 | ubifs_dump_inode(c, inode);
|
| 3569 | dump_stack();
|
| 3570 | return -EINVAL;
|
| 3571 |
|
| 3572 | out_unlock:
|
| 3573 | mutex_unlock(&c->tnc_mutex);
|
| 3574 | return err;
|
| 3575 | }
|