linux/fs/jffs2/xattr.c
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   1/*
   2 * JFFS2 -- Journalling Flash File System, Version 2.
   3 *
   4 * Copyright © 2006  NEC Corporation
   5 *
   6 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
   7 *
   8 * For licensing information, see the file 'LICENCE' in this directory.
   9 *
  10 */
  11
  12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14#define JFFS2_XATTR_IS_CORRUPTED        1
  15
  16#include <linux/kernel.h>
  17#include <linux/slab.h>
  18#include <linux/fs.h>
  19#include <linux/time.h>
  20#include <linux/pagemap.h>
  21#include <linux/highmem.h>
  22#include <linux/crc32.h>
  23#include <linux/jffs2.h>
  24#include <linux/xattr.h>
  25#include <linux/posix_acl_xattr.h>
  26#include <linux/mtd/mtd.h>
  27#include "nodelist.h"
  28/* -------- xdatum related functions ----------------
  29 * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  30 *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  31 *   the index of the xattr name/value pair cache (c->xattrindex).
  32 * is_xattr_datum_unchecked(c, xd)
  33 *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  34 *   unchecked, it returns 0.
  35 * unload_xattr_datum(c, xd)
  36 *   is used to release xattr name/value pair and detach from c->xattrindex.
  37 * reclaim_xattr_datum(c)
  38 *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  39 *   memory usage by cache is over c->xdatum_mem_threshold. Currently, this threshold
  40 *   is hard coded as 32KiB.
  41 * do_verify_xattr_datum(c, xd)
  42 *   is used to load the xdatum informations without name/value pair from the medium.
  43 *   It's necessary once, because those informations are not collected during mounting
  44 *   process when EBS is enabled.
  45 *   0 will be returned, if success. An negative return value means recoverable error, and
  46 *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  47 *   and xref when it returned positive value.
  48 * do_load_xattr_datum(c, xd)
  49 *   is used to load name/value pair from the medium.
  50 *   The meanings of return value is same as do_verify_xattr_datum().
  51 * load_xattr_datum(c, xd)
  52 *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  53 *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  54 *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  55 * save_xattr_datum(c, xd)
  56 *   is used to write xdatum to medium. xd->version will be incremented.
  57 * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  58 *   is used to create new xdatum and write to medium.
  59 * unrefer_xattr_datum(c, xd)
  60 *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
  61 *   is set on xd->flags and chained xattr_dead_list or release it immediately.
  62 *   In the first case, the garbage collector release it later.
  63 * -------------------------------------------------- */
  64static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
  65{
  66        int name_len = strlen(xname);
  67
  68        return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
  69}
  70
  71static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  72{
  73        struct jffs2_raw_node_ref *raw;
  74        int rc = 0;
  75
  76        spin_lock(&c->erase_completion_lock);
  77        for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
  78                if (ref_flags(raw) == REF_UNCHECKED) {
  79                        rc = 1;
  80                        break;
  81                }
  82        }
  83        spin_unlock(&c->erase_completion_lock);
  84        return rc;
  85}
  86
  87static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  88{
  89        /* must be called under down_write(xattr_sem) */
  90        D1(dbg_xattr("%s: xid=%u, version=%u\n", __func__, xd->xid, xd->version));
  91        if (xd->xname) {
  92                c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  93                kfree(xd->xname);
  94        }
  95
  96        list_del_init(&xd->xindex);
  97        xd->hashkey = 0;
  98        xd->xname = NULL;
  99        xd->xvalue = NULL;
 100}
 101
 102static void reclaim_xattr_datum(struct jffs2_sb_info *c)
 103{
 104        /* must be called under down_write(xattr_sem) */
 105        struct jffs2_xattr_datum *xd, *_xd;
 106        uint32_t target, before;
 107        static int index = 0;
 108        int count;
 109
 110        if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
 111                return;
 112
 113        before = c->xdatum_mem_usage;
 114        target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
 115        for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
 116                list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
 117                        if (xd->flags & JFFS2_XFLAGS_HOT) {
 118                                xd->flags &= ~JFFS2_XFLAGS_HOT;
 119                        } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
 120                                unload_xattr_datum(c, xd);
 121                        }
 122                        if (c->xdatum_mem_usage <= target)
 123                                goto out;
 124                }
 125                index = (index+1) % XATTRINDEX_HASHSIZE;
 126        }
 127 out:
 128        JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 129                     before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 130}
 131
 132static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 133{
 134        /* must be called under down_write(xattr_sem) */
 135        struct jffs2_eraseblock *jeb;
 136        struct jffs2_raw_node_ref *raw;
 137        struct jffs2_raw_xattr rx;
 138        size_t readlen;
 139        uint32_t crc, offset, totlen;
 140        int rc;
 141
 142        spin_lock(&c->erase_completion_lock);
 143        offset = ref_offset(xd->node);
 144        if (ref_flags(xd->node) == REF_PRISTINE)
 145                goto complete;
 146        spin_unlock(&c->erase_completion_lock);
 147
 148        rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
 149        if (rc || readlen != sizeof(rx)) {
 150                JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
 151                              rc, sizeof(rx), readlen, offset);
 152                return rc ? rc : -EIO;
 153        }
 154        crc = crc32(0, &rx, sizeof(rx) - 4);
 155        if (crc != je32_to_cpu(rx.node_crc)) {
 156                JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 157                            offset, je32_to_cpu(rx.hdr_crc), crc);
 158                xd->flags |= JFFS2_XFLAGS_INVALID;
 159                return JFFS2_XATTR_IS_CORRUPTED;
 160        }
 161        totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 162        if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 163            || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 164            || je32_to_cpu(rx.totlen) != totlen
 165            || je32_to_cpu(rx.xid) != xd->xid
 166            || je32_to_cpu(rx.version) != xd->version) {
 167                JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 168                            "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 169                            offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
 170                            je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
 171                            je32_to_cpu(rx.totlen), totlen,
 172                            je32_to_cpu(rx.xid), xd->xid,
 173                            je32_to_cpu(rx.version), xd->version);
 174                xd->flags |= JFFS2_XFLAGS_INVALID;
 175                return JFFS2_XATTR_IS_CORRUPTED;
 176        }
 177        xd->xprefix = rx.xprefix;
 178        xd->name_len = rx.name_len;
 179        xd->value_len = je16_to_cpu(rx.value_len);
 180        xd->data_crc = je32_to_cpu(rx.data_crc);
 181
 182        spin_lock(&c->erase_completion_lock);
 183 complete:
 184        for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
 185                jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 186                totlen = PAD(ref_totlen(c, jeb, raw));
 187                if (ref_flags(raw) == REF_UNCHECKED) {
 188                        c->unchecked_size -= totlen; c->used_size += totlen;
 189                        jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 190                }
 191                raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
 192        }
 193        spin_unlock(&c->erase_completion_lock);
 194
 195        /* unchecked xdatum is chained with c->xattr_unchecked */
 196        list_del_init(&xd->xindex);
 197
 198        dbg_xattr("success on verifying xdatum (xid=%u, version=%u)\n",
 199                  xd->xid, xd->version);
 200
 201        return 0;
 202}
 203
 204static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 205{
 206        /* must be called under down_write(xattr_sem) */
 207        char *data;
 208        size_t readlen;
 209        uint32_t crc, length;
 210        int i, ret, retry = 0;
 211
 212        BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 213        BUG_ON(!list_empty(&xd->xindex));
 214 retry:
 215        length = xd->name_len + 1 + xd->value_len;
 216        data = kmalloc(length, GFP_KERNEL);
 217        if (!data)
 218                return -ENOMEM;
 219
 220        ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 221                               length, &readlen, data);
 222
 223        if (ret || length!=readlen) {
 224                JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
 225                              ret, length, readlen, ref_offset(xd->node));
 226                kfree(data);
 227                return ret ? ret : -EIO;
 228        }
 229
 230        data[xd->name_len] = '\0';
 231        crc = crc32(0, data, length);
 232        if (crc != xd->data_crc) {
 233                JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XATTR)"
 234                              " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 235                              ref_offset(xd->node), xd->data_crc, crc);
 236                kfree(data);
 237                xd->flags |= JFFS2_XFLAGS_INVALID;
 238                return JFFS2_XATTR_IS_CORRUPTED;
 239        }
 240
 241        xd->flags |= JFFS2_XFLAGS_HOT;
 242        xd->xname = data;
 243        xd->xvalue = data + xd->name_len+1;
 244
 245        c->xdatum_mem_usage += length;
 246
 247        xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 248        i = xd->hashkey % XATTRINDEX_HASHSIZE;
 249        list_add(&xd->xindex, &c->xattrindex[i]);
 250        if (!retry) {
 251                retry = 1;
 252                reclaim_xattr_datum(c);
 253                if (!xd->xname)
 254                        goto retry;
 255        }
 256
 257        dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 258                  xd->xid, xd->xprefix, xd->xname);
 259
 260        return 0;
 261}
 262
 263static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 264{
 265        /* must be called under down_write(xattr_sem);
 266         * rc < 0 : recoverable error, try again
 267         * rc = 0 : success
 268         * rc > 0 : Unrecoverable error, this node should be deleted.
 269         */
 270        int rc = 0;
 271
 272        BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
 273        if (xd->xname)
 274                return 0;
 275        if (xd->flags & JFFS2_XFLAGS_INVALID)
 276                return JFFS2_XATTR_IS_CORRUPTED;
 277        if (unlikely(is_xattr_datum_unchecked(c, xd)))
 278                rc = do_verify_xattr_datum(c, xd);
 279        if (!rc)
 280                rc = do_load_xattr_datum(c, xd);
 281        return rc;
 282}
 283
 284static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 285{
 286        /* must be called under down_write(xattr_sem) */
 287        struct jffs2_raw_xattr rx;
 288        struct kvec vecs[2];
 289        size_t length;
 290        int rc, totlen;
 291        uint32_t phys_ofs = write_ofs(c);
 292
 293        BUG_ON(!xd->xname);
 294        BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
 295
 296        vecs[0].iov_base = &rx;
 297        vecs[0].iov_len = sizeof(rx);
 298        vecs[1].iov_base = xd->xname;
 299        vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 300        totlen = vecs[0].iov_len + vecs[1].iov_len;
 301
 302        /* Setup raw-xattr */
 303        memset(&rx, 0, sizeof(rx));
 304        rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 305        rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 306        rx.totlen = cpu_to_je32(PAD(totlen));
 307        rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 308
 309        rx.xid = cpu_to_je32(xd->xid);
 310        rx.version = cpu_to_je32(++xd->version);
 311        rx.xprefix = xd->xprefix;
 312        rx.name_len = xd->name_len;
 313        rx.value_len = cpu_to_je16(xd->value_len);
 314        rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 315        rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 316
 317        rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 318        if (rc || totlen != length) {
 319                JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
 320                              rc, totlen, length, phys_ofs);
 321                rc = rc ? rc : -EIO;
 322                if (length)
 323                        jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
 324
 325                return rc;
 326        }
 327        /* success */
 328        jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
 329
 330        dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 331                  xd->xid, xd->version, xd->xprefix, xd->xname);
 332
 333        return 0;
 334}
 335
 336static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 337                                                    int xprefix, const char *xname,
 338                                                    const char *xvalue, int xsize)
 339{
 340        /* must be called under down_write(xattr_sem) */
 341        struct jffs2_xattr_datum *xd;
 342        uint32_t hashkey, name_len;
 343        char *data;
 344        int i, rc;
 345
 346        /* Search xattr_datum has same xname/xvalue by index */
 347        hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 348        i = hashkey % XATTRINDEX_HASHSIZE;
 349        list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 350                if (xd->hashkey==hashkey
 351                    && xd->xprefix==xprefix
 352                    && xd->value_len==xsize
 353                    && !strcmp(xd->xname, xname)
 354                    && !memcmp(xd->xvalue, xvalue, xsize)) {
 355                        atomic_inc(&xd->refcnt);
 356                        return xd;
 357                }
 358        }
 359
 360        /* Not found, Create NEW XATTR-Cache */
 361        name_len = strlen(xname);
 362
 363        xd = jffs2_alloc_xattr_datum();
 364        if (!xd)
 365                return ERR_PTR(-ENOMEM);
 366
 367        data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 368        if (!data) {
 369                jffs2_free_xattr_datum(xd);
 370                return ERR_PTR(-ENOMEM);
 371        }
 372        strcpy(data, xname);
 373        memcpy(data + name_len + 1, xvalue, xsize);
 374
 375        atomic_set(&xd->refcnt, 1);
 376        xd->xid = ++c->highest_xid;
 377        xd->flags |= JFFS2_XFLAGS_HOT;
 378        xd->xprefix = xprefix;
 379
 380        xd->hashkey = hashkey;
 381        xd->xname = data;
 382        xd->xvalue = data + name_len + 1;
 383        xd->name_len = name_len;
 384        xd->value_len = xsize;
 385        xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 386
 387        rc = save_xattr_datum(c, xd);
 388        if (rc) {
 389                kfree(xd->xname);
 390                jffs2_free_xattr_datum(xd);
 391                return ERR_PTR(rc);
 392        }
 393
 394        /* Insert Hash Index */
 395        i = hashkey % XATTRINDEX_HASHSIZE;
 396        list_add(&xd->xindex, &c->xattrindex[i]);
 397
 398        c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 399        reclaim_xattr_datum(c);
 400
 401        return xd;
 402}
 403
 404static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 405{
 406        /* must be called under down_write(xattr_sem) */
 407        if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
 408                unload_xattr_datum(c, xd);
 409                xd->flags |= JFFS2_XFLAGS_DEAD;
 410                if (xd->node == (void *)xd) {
 411                        BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 412                        jffs2_free_xattr_datum(xd);
 413                } else {
 414                        list_add(&xd->xindex, &c->xattr_dead_list);
 415                }
 416                spin_unlock(&c->erase_completion_lock);
 417
 418                dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
 419                          xd->xid, xd->version);
 420        }
 421}
 422
 423/* -------- xref related functions ------------------
 424 * verify_xattr_ref(c, ref)
 425 *   is used to load xref information from medium. Because summary data does not
 426 *   contain xid/ino, it's necessary to verify once while mounting process.
 427 * save_xattr_ref(c, ref)
 428 *   is used to write xref to medium. If delete marker is marked, it write
 429 *   a delete marker of xref into medium.
 430 * create_xattr_ref(c, ic, xd)
 431 *   is used to create a new xref and write to medium.
 432 * delete_xattr_ref(c, ref)
 433 *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 434 *   and allows GC to reclaim those physical nodes.
 435 * jffs2_xattr_delete_inode(c, ic)
 436 *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 437 * jffs2_xattr_free_inode(c, ic)
 438 *   is called to release xattr related objects when unmounting. 
 439 * check_xattr_ref_inode(c, ic)
 440 *   is used to confirm inode does not have duplicate xattr name/value pair.
 441 * jffs2_xattr_do_crccheck_inode(c, ic)
 442 *   is used to force xattr data integrity check during the initial gc scan.
 443 * -------------------------------------------------- */
 444static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 445{
 446        struct jffs2_eraseblock *jeb;
 447        struct jffs2_raw_node_ref *raw;
 448        struct jffs2_raw_xref rr;
 449        size_t readlen;
 450        uint32_t crc, offset, totlen;
 451        int rc;
 452
 453        spin_lock(&c->erase_completion_lock);
 454        if (ref_flags(ref->node) != REF_UNCHECKED)
 455                goto complete;
 456        offset = ref_offset(ref->node);
 457        spin_unlock(&c->erase_completion_lock);
 458
 459        rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
 460        if (rc || sizeof(rr) != readlen) {
 461                JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
 462                              rc, sizeof(rr), readlen, offset);
 463                return rc ? rc : -EIO;
 464        }
 465        /* obsolete node */
 466        crc = crc32(0, &rr, sizeof(rr) - 4);
 467        if (crc != je32_to_cpu(rr.node_crc)) {
 468                JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 469                            offset, je32_to_cpu(rr.node_crc), crc);
 470                return JFFS2_XATTR_IS_CORRUPTED;
 471        }
 472        if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 473            || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 474            || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 475                JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 476                            "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
 477                            offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 478                            je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 479                            je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 480                return JFFS2_XATTR_IS_CORRUPTED;
 481        }
 482        ref->ino = je32_to_cpu(rr.ino);
 483        ref->xid = je32_to_cpu(rr.xid);
 484        ref->xseqno = je32_to_cpu(rr.xseqno);
 485        if (ref->xseqno > c->highest_xseqno)
 486                c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 487
 488        spin_lock(&c->erase_completion_lock);
 489 complete:
 490        for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
 491                jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 492                totlen = PAD(ref_totlen(c, jeb, raw));
 493                if (ref_flags(raw) == REF_UNCHECKED) {
 494                        c->unchecked_size -= totlen; c->used_size += totlen;
 495                        jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 496                }
 497                raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
 498        }
 499        spin_unlock(&c->erase_completion_lock);
 500
 501        dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 502                  ref->ino, ref->xid, ref_offset(ref->node));
 503        return 0;
 504}
 505
 506static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 507{
 508        /* must be called under down_write(xattr_sem) */
 509        struct jffs2_raw_xref rr;
 510        size_t length;
 511        uint32_t xseqno, phys_ofs = write_ofs(c);
 512        int ret;
 513
 514        rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 515        rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 516        rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 517        rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 518
 519        xseqno = (c->highest_xseqno += 2);
 520        if (is_xattr_ref_dead(ref)) {
 521                xseqno |= XREF_DELETE_MARKER;
 522                rr.ino = cpu_to_je32(ref->ino);
 523                rr.xid = cpu_to_je32(ref->xid);
 524        } else {
 525                rr.ino = cpu_to_je32(ref->ic->ino);
 526                rr.xid = cpu_to_je32(ref->xd->xid);
 527        }
 528        rr.xseqno = cpu_to_je32(xseqno);
 529        rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 530
 531        ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 532        if (ret || sizeof(rr) != length) {
 533                JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
 534                              ret, sizeof(rr), length, phys_ofs);
 535                ret = ret ? ret : -EIO;
 536                if (length)
 537                        jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
 538
 539                return ret;
 540        }
 541        /* success */
 542        ref->xseqno = xseqno;
 543        jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
 544
 545        dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 546
 547        return 0;
 548}
 549
 550static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 551                                                struct jffs2_xattr_datum *xd)
 552{
 553        /* must be called under down_write(xattr_sem) */
 554        struct jffs2_xattr_ref *ref;
 555        int ret;
 556
 557        ref = jffs2_alloc_xattr_ref();
 558        if (!ref)
 559                return ERR_PTR(-ENOMEM);
 560        ref->ic = ic;
 561        ref->xd = xd;
 562
 563        ret = save_xattr_ref(c, ref);
 564        if (ret) {
 565                jffs2_free_xattr_ref(ref);
 566                return ERR_PTR(ret);
 567        }
 568
 569        /* Chain to inode */
 570        ref->next = ic->xref;
 571        ic->xref = ref;
 572
 573        return ref; /* success */
 574}
 575
 576static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 577{
 578        /* must be called under down_write(xattr_sem) */
 579        struct jffs2_xattr_datum *xd;
 580
 581        xd = ref->xd;
 582        ref->xseqno |= XREF_DELETE_MARKER;
 583        ref->ino = ref->ic->ino;
 584        ref->xid = ref->xd->xid;
 585        spin_lock(&c->erase_completion_lock);
 586        ref->next = c->xref_dead_list;
 587        c->xref_dead_list = ref;
 588        spin_unlock(&c->erase_completion_lock);
 589
 590        dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
 591                  ref->ino, ref->xid, ref->xseqno);
 592
 593        unrefer_xattr_datum(c, xd);
 594}
 595
 596void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 597{
 598        /* It's called from jffs2_evict_inode() on inode removing.
 599           When an inode with XATTR is removed, those XATTRs must be removed. */
 600        struct jffs2_xattr_ref *ref, *_ref;
 601
 602        if (!ic || ic->pino_nlink > 0)
 603                return;
 604
 605        down_write(&c->xattr_sem);
 606        for (ref = ic->xref; ref; ref = _ref) {
 607                _ref = ref->next;
 608                delete_xattr_ref(c, ref);
 609        }
 610        ic->xref = NULL;
 611        up_write(&c->xattr_sem);
 612}
 613
 614void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 615{
 616        /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 617        struct jffs2_xattr_datum *xd;
 618        struct jffs2_xattr_ref *ref, *_ref;
 619
 620        down_write(&c->xattr_sem);
 621        for (ref = ic->xref; ref; ref = _ref) {
 622                _ref = ref->next;
 623                xd = ref->xd;
 624                if (atomic_dec_and_test(&xd->refcnt)) {
 625                        unload_xattr_datum(c, xd);
 626                        jffs2_free_xattr_datum(xd);
 627                }
 628                jffs2_free_xattr_ref(ref);
 629        }
 630        ic->xref = NULL;
 631        up_write(&c->xattr_sem);
 632}
 633
 634static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 635{
 636        /* success of check_xattr_ref_inode() means that inode (ic) dose not have
 637         * duplicate name/value pairs. If duplicate name/value pair would be found,
 638         * one will be removed.
 639         */
 640        struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 641        int rc = 0;
 642
 643        if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 644                return 0;
 645        down_write(&c->xattr_sem);
 646 retry:
 647        rc = 0;
 648        for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 649                if (!ref->xd->xname) {
 650                        rc = load_xattr_datum(c, ref->xd);
 651                        if (unlikely(rc > 0)) {
 652                                *pref = ref->next;
 653                                delete_xattr_ref(c, ref);
 654                                goto retry;
 655                        } else if (unlikely(rc < 0))
 656                                goto out;
 657                }
 658                for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 659                        if (!cmp->xd->xname) {
 660                                ref->xd->flags |= JFFS2_XFLAGS_BIND;
 661                                rc = load_xattr_datum(c, cmp->xd);
 662                                ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 663                                if (unlikely(rc > 0)) {
 664                                        *pcmp = cmp->next;
 665                                        delete_xattr_ref(c, cmp);
 666                                        goto retry;
 667                                } else if (unlikely(rc < 0))
 668                                        goto out;
 669                        }
 670                        if (ref->xd->xprefix == cmp->xd->xprefix
 671                            && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 672                                if (ref->xseqno > cmp->xseqno) {
 673                                        *pcmp = cmp->next;
 674                                        delete_xattr_ref(c, cmp);
 675                                } else {
 676                                        *pref = ref->next;
 677                                        delete_xattr_ref(c, ref);
 678                                }
 679                                goto retry;
 680                        }
 681                }
 682        }
 683        ic->flags |= INO_FLAGS_XATTR_CHECKED;
 684 out:
 685        up_write(&c->xattr_sem);
 686
 687        return rc;
 688}
 689
 690void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 691{
 692        check_xattr_ref_inode(c, ic);
 693}
 694
 695/* -------- xattr subsystem functions ---------------
 696 * jffs2_init_xattr_subsystem(c)
 697 *   is used to initialize semaphore and list_head, and some variables.
 698 * jffs2_find_xattr_datum(c, xid)
 699 *   is used to lookup xdatum while scanning process.
 700 * jffs2_clear_xattr_subsystem(c)
 701 *   is used to release any xattr related objects.
 702 * jffs2_build_xattr_subsystem(c)
 703 *   is used to associate xdatum and xref while super block building process.
 704 * jffs2_setup_xattr_datum(c, xid, version)
 705 *   is used to insert xdatum while scanning process.
 706 * -------------------------------------------------- */
 707void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 708{
 709        int i;
 710
 711        for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 712                INIT_LIST_HEAD(&c->xattrindex[i]);
 713        INIT_LIST_HEAD(&c->xattr_unchecked);
 714        INIT_LIST_HEAD(&c->xattr_dead_list);
 715        c->xref_dead_list = NULL;
 716        c->xref_temp = NULL;
 717
 718        init_rwsem(&c->xattr_sem);
 719        c->highest_xid = 0;
 720        c->highest_xseqno = 0;
 721        c->xdatum_mem_usage = 0;
 722        c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 723}
 724
 725static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 726{
 727        struct jffs2_xattr_datum *xd;
 728        int i = xid % XATTRINDEX_HASHSIZE;
 729
 730        /* It's only used in scanning/building process. */
 731        BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 732
 733        list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 734                if (xd->xid==xid)
 735                        return xd;
 736        }
 737        return NULL;
 738}
 739
 740void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 741{
 742        struct jffs2_xattr_datum *xd, *_xd;
 743        struct jffs2_xattr_ref *ref, *_ref;
 744        int i;
 745
 746        for (ref=c->xref_temp; ref; ref = _ref) {
 747                _ref = ref->next;
 748                jffs2_free_xattr_ref(ref);
 749        }
 750
 751        for (ref=c->xref_dead_list; ref; ref = _ref) {
 752                _ref = ref->next;
 753                jffs2_free_xattr_ref(ref);
 754        }
 755
 756        for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 757                list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 758                        list_del(&xd->xindex);
 759                        kfree(xd->xname);
 760                        jffs2_free_xattr_datum(xd);
 761                }
 762        }
 763
 764        list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
 765                list_del(&xd->xindex);
 766                jffs2_free_xattr_datum(xd);
 767        }
 768        list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
 769                list_del(&xd->xindex);
 770                jffs2_free_xattr_datum(xd);
 771        }
 772}
 773
 774#define XREF_TMPHASH_SIZE       (128)
 775void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 776{
 777        struct jffs2_xattr_ref *ref, *_ref;
 778        struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
 779        struct jffs2_xattr_datum *xd, *_xd;
 780        struct jffs2_inode_cache *ic;
 781        struct jffs2_raw_node_ref *raw;
 782        int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
 783        int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
 784
 785        BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 786
 787        /* Phase.1 : Merge same xref */
 788        for (i=0; i < XREF_TMPHASH_SIZE; i++)
 789                xref_tmphash[i] = NULL;
 790        for (ref=c->xref_temp; ref; ref=_ref) {
 791                struct jffs2_xattr_ref *tmp;
 792
 793                _ref = ref->next;
 794                if (ref_flags(ref->node) != REF_PRISTINE) {
 795                        if (verify_xattr_ref(c, ref)) {
 796                                BUG_ON(ref->node->next_in_ino != (void *)ref);
 797                                ref->node->next_in_ino = NULL;
 798                                jffs2_mark_node_obsolete(c, ref->node);
 799                                jffs2_free_xattr_ref(ref);
 800                                continue;
 801                        }
 802                }
 803
 804                i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
 805                for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
 806                        if (tmp->ino == ref->ino && tmp->xid == ref->xid)
 807                                break;
 808                }
 809                if (tmp) {
 810                        raw = ref->node;
 811                        if (ref->xseqno > tmp->xseqno) {
 812                                tmp->xseqno = ref->xseqno;
 813                                raw->next_in_ino = tmp->node;
 814                                tmp->node = raw;
 815                        } else {
 816                                raw->next_in_ino = tmp->node->next_in_ino;
 817                                tmp->node->next_in_ino = raw;
 818                        }
 819                        jffs2_free_xattr_ref(ref);
 820                        continue;
 821                } else {
 822                        ref->next = xref_tmphash[i];
 823                        xref_tmphash[i] = ref;
 824                }
 825        }
 826        c->xref_temp = NULL;
 827
 828        /* Phase.2 : Bind xref with inode_cache and xattr_datum */
 829        for (i=0; i < XREF_TMPHASH_SIZE; i++) {
 830                for (ref=xref_tmphash[i]; ref; ref=_ref) {
 831                        xref_count++;
 832                        _ref = ref->next;
 833                        if (is_xattr_ref_dead(ref)) {
 834                                ref->next = c->xref_dead_list;
 835                                c->xref_dead_list = ref;
 836                                xref_dead_count++;
 837                                continue;
 838                        }
 839                        /* At this point, ref->xid and ref->ino contain XID and inode number.
 840                           ref->xd and ref->ic are not valid yet. */
 841                        xd = jffs2_find_xattr_datum(c, ref->xid);
 842                        ic = jffs2_get_ino_cache(c, ref->ino);
 843                        if (!xd || !ic || !ic->pino_nlink) {
 844                                dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
 845                                          ref->ino, ref->xid, ref->xseqno);
 846                                ref->xseqno |= XREF_DELETE_MARKER;
 847                                ref->next = c->xref_dead_list;
 848                                c->xref_dead_list = ref;
 849                                xref_orphan_count++;
 850                                continue;
 851                        }
 852                        ref->xd = xd;
 853                        ref->ic = ic;
 854                        atomic_inc(&xd->refcnt);
 855                        ref->next = ic->xref;
 856                        ic->xref = ref;
 857                }
 858        }
 859
 860        /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
 861        for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 862                list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 863                        xdatum_count++;
 864                        list_del_init(&xd->xindex);
 865                        if (!atomic_read(&xd->refcnt)) {
 866                                dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
 867                                          xd->xid, xd->version);
 868                                xd->flags |= JFFS2_XFLAGS_DEAD;
 869                                list_add(&xd->xindex, &c->xattr_unchecked);
 870                                xdatum_orphan_count++;
 871                                continue;
 872                        }
 873                        if (is_xattr_datum_unchecked(c, xd)) {
 874                                dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
 875                                          xd->xid, xd->version);
 876                                list_add(&xd->xindex, &c->xattr_unchecked);
 877                                xdatum_unchecked_count++;
 878                        }
 879                }
 880        }
 881        /* build complete */
 882        JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
 883                     " (%u unchecked, %u orphan) and "
 884                     "%u of xref (%u dead, %u orphan) found.\n",
 885                     xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
 886                     xref_count, xref_dead_count, xref_orphan_count);
 887}
 888
 889struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 890                                                  uint32_t xid, uint32_t version)
 891{
 892        struct jffs2_xattr_datum *xd;
 893
 894        xd = jffs2_find_xattr_datum(c, xid);
 895        if (!xd) {
 896                xd = jffs2_alloc_xattr_datum();
 897                if (!xd)
 898                        return ERR_PTR(-ENOMEM);
 899                xd->xid = xid;
 900                xd->version = version;
 901                if (xd->xid > c->highest_xid)
 902                        c->highest_xid = xd->xid;
 903                list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 904        }
 905        return xd;
 906}
 907
 908/* -------- xattr subsystem functions ---------------
 909 * xprefix_to_handler(xprefix)
 910 *   is used to translate xprefix into xattr_handler.
 911 * jffs2_listxattr(dentry, buffer, size)
 912 *   is an implementation of listxattr handler on jffs2.
 913 * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 914 *   is an implementation of getxattr handler on jffs2.
 915 * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 916 *   is an implementation of setxattr handler on jffs2.
 917 * -------------------------------------------------- */
 918const struct xattr_handler *jffs2_xattr_handlers[] = {
 919        &jffs2_user_xattr_handler,
 920#ifdef CONFIG_JFFS2_FS_SECURITY
 921        &jffs2_security_xattr_handler,
 922#endif
 923#ifdef CONFIG_JFFS2_FS_POSIX_ACL
 924        &posix_acl_access_xattr_handler,
 925        &posix_acl_default_xattr_handler,
 926#endif
 927        &jffs2_trusted_xattr_handler,
 928        NULL
 929};
 930
 931static const struct xattr_handler *xprefix_to_handler(int xprefix) {
 932        const struct xattr_handler *ret;
 933
 934        switch (xprefix) {
 935        case JFFS2_XPREFIX_USER:
 936                ret = &jffs2_user_xattr_handler;
 937                break;
 938#ifdef CONFIG_JFFS2_FS_SECURITY
 939        case JFFS2_XPREFIX_SECURITY:
 940                ret = &jffs2_security_xattr_handler;
 941                break;
 942#endif
 943#ifdef CONFIG_JFFS2_FS_POSIX_ACL
 944        case JFFS2_XPREFIX_ACL_ACCESS:
 945                ret = &posix_acl_access_xattr_handler;
 946                break;
 947        case JFFS2_XPREFIX_ACL_DEFAULT:
 948                ret = &posix_acl_default_xattr_handler;
 949                break;
 950#endif
 951        case JFFS2_XPREFIX_TRUSTED:
 952                ret = &jffs2_trusted_xattr_handler;
 953                break;
 954        default:
 955                ret = NULL;
 956                break;
 957        }
 958        return ret;
 959}
 960
 961ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 962{
 963        struct inode *inode = d_inode(dentry);
 964        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 965        struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 966        struct jffs2_inode_cache *ic = f->inocache;
 967        struct jffs2_xattr_ref *ref, **pref;
 968        struct jffs2_xattr_datum *xd;
 969        const struct xattr_handler *xhandle;
 970        const char *prefix;
 971        ssize_t prefix_len, len, rc;
 972        int retry = 0;
 973
 974        rc = check_xattr_ref_inode(c, ic);
 975        if (unlikely(rc))
 976                return rc;
 977
 978        down_read(&c->xattr_sem);
 979 retry:
 980        len = 0;
 981        for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 982                BUG_ON(ref->ic != ic);
 983                xd = ref->xd;
 984                if (!xd->xname) {
 985                        /* xdatum is unchached */
 986                        if (!retry) {
 987                                retry = 1;
 988                                up_read(&c->xattr_sem);
 989                                down_write(&c->xattr_sem);
 990                                goto retry;
 991                        } else {
 992                                rc = load_xattr_datum(c, xd);
 993                                if (unlikely(rc > 0)) {
 994                                        *pref = ref->next;
 995                                        delete_xattr_ref(c, ref);
 996                                        goto retry;
 997                                } else if (unlikely(rc < 0))
 998                                        goto out;
 999                        }
1000                }
1001                xhandle = xprefix_to_handler(xd->xprefix);
1002                if (!xhandle || (xhandle->list && !xhandle->list(dentry)))
1003                        continue;
1004                prefix = xhandle->prefix ?: xhandle->name;
1005                prefix_len = strlen(prefix);
1006                rc = prefix_len + xd->name_len + 1;
1007
1008                if (buffer) {
1009                        if (rc > size - len) {
1010                                rc = -ERANGE;
1011                                goto out;
1012                        }
1013                        memcpy(buffer, prefix, prefix_len);
1014                        buffer += prefix_len;
1015                        memcpy(buffer, xd->xname, xd->name_len);
1016                        buffer += xd->name_len;
1017                        *buffer++ = 0;
1018                }
1019                len += rc;
1020        }
1021        rc = len;
1022 out:
1023        if (!retry) {
1024                up_read(&c->xattr_sem);
1025        } else {
1026                up_write(&c->xattr_sem);
1027        }
1028        return rc;
1029}
1030
1031int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1032                      char *buffer, size_t size)
1033{
1034        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1035        struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1036        struct jffs2_inode_cache *ic = f->inocache;
1037        struct jffs2_xattr_datum *xd;
1038        struct jffs2_xattr_ref *ref, **pref;
1039        int rc, retry = 0;
1040
1041        rc = check_xattr_ref_inode(c, ic);
1042        if (unlikely(rc))
1043                return rc;
1044
1045        down_read(&c->xattr_sem);
1046 retry:
1047        for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1048                BUG_ON(ref->ic!=ic);
1049
1050                xd = ref->xd;
1051                if (xd->xprefix != xprefix)
1052                        continue;
1053                if (!xd->xname) {
1054                        /* xdatum is unchached */
1055                        if (!retry) {
1056                                retry = 1;
1057                                up_read(&c->xattr_sem);
1058                                down_write(&c->xattr_sem);
1059                                goto retry;
1060                        } else {
1061                                rc = load_xattr_datum(c, xd);
1062                                if (unlikely(rc > 0)) {
1063                                        *pref = ref->next;
1064                                        delete_xattr_ref(c, ref);
1065                                        goto retry;
1066                                } else if (unlikely(rc < 0)) {
1067                                        goto out;
1068                                }
1069                        }
1070                }
1071                if (!strcmp(xname, xd->xname)) {
1072                        rc = xd->value_len;
1073                        if (buffer) {
1074                                if (size < rc) {
1075                                        rc = -ERANGE;
1076                                } else {
1077                                        memcpy(buffer, xd->xvalue, rc);
1078                                }
1079                        }
1080                        goto out;
1081                }
1082        }
1083        rc = -ENODATA;
1084 out:
1085        if (!retry) {
1086                up_read(&c->xattr_sem);
1087        } else {
1088                up_write(&c->xattr_sem);
1089        }
1090        return rc;
1091}
1092
1093int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1094                      const char *buffer, size_t size, int flags)
1095{
1096        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1097        struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1098        struct jffs2_inode_cache *ic = f->inocache;
1099        struct jffs2_xattr_datum *xd;
1100        struct jffs2_xattr_ref *ref, *newref, **pref;
1101        uint32_t length, request;
1102        int rc;
1103
1104        rc = check_xattr_ref_inode(c, ic);
1105        if (unlikely(rc))
1106                return rc;
1107
1108        request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1109        rc = jffs2_reserve_space(c, request, &length,
1110                                 ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1111        if (rc) {
1112                JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1113                return rc;
1114        }
1115
1116        /* Find existing xattr */
1117        down_write(&c->xattr_sem);
1118 retry:
1119        for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1120                xd = ref->xd;
1121                if (xd->xprefix != xprefix)
1122                        continue;
1123                if (!xd->xname) {
1124                        rc = load_xattr_datum(c, xd);
1125                        if (unlikely(rc > 0)) {
1126                                *pref = ref->next;
1127                                delete_xattr_ref(c, ref);
1128                                goto retry;
1129                        } else if (unlikely(rc < 0))
1130                                goto out;
1131                }
1132                if (!strcmp(xd->xname, xname)) {
1133                        if (flags & XATTR_CREATE) {
1134                                rc = -EEXIST;
1135                                goto out;
1136                        }
1137                        if (!buffer) {
1138                                ref->ino = ic->ino;
1139                                ref->xid = xd->xid;
1140                                ref->xseqno |= XREF_DELETE_MARKER;
1141                                rc = save_xattr_ref(c, ref);
1142                                if (!rc) {
1143                                        *pref = ref->next;
1144                                        spin_lock(&c->erase_completion_lock);
1145                                        ref->next = c->xref_dead_list;
1146                                        c->xref_dead_list = ref;
1147                                        spin_unlock(&c->erase_completion_lock);
1148                                        unrefer_xattr_datum(c, xd);
1149                                } else {
1150                                        ref->ic = ic;
1151                                        ref->xd = xd;
1152                                        ref->xseqno &= ~XREF_DELETE_MARKER;
1153                                }
1154                                goto out;
1155                        }
1156                        goto found;
1157                }
1158        }
1159        /* not found */
1160        if (flags & XATTR_REPLACE) {
1161                rc = -ENODATA;
1162                goto out;
1163        }
1164        if (!buffer) {
1165                rc = -ENODATA;
1166                goto out;
1167        }
1168 found:
1169        xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1170        if (IS_ERR(xd)) {
1171                rc = PTR_ERR(xd);
1172                goto out;
1173        }
1174        up_write(&c->xattr_sem);
1175        jffs2_complete_reservation(c);
1176
1177        /* create xattr_ref */
1178        request = PAD(sizeof(struct jffs2_raw_xref));
1179        rc = jffs2_reserve_space(c, request, &length,
1180                                 ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1181        down_write(&c->xattr_sem);
1182        if (rc) {
1183                JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1184                unrefer_xattr_datum(c, xd);
1185                up_write(&c->xattr_sem);
1186                return rc;
1187        }
1188        if (ref)
1189                *pref = ref->next;
1190        newref = create_xattr_ref(c, ic, xd);
1191        if (IS_ERR(newref)) {
1192                if (ref) {
1193                        ref->next = ic->xref;
1194                        ic->xref = ref;
1195                }
1196                rc = PTR_ERR(newref);
1197                unrefer_xattr_datum(c, xd);
1198        } else if (ref) {
1199                delete_xattr_ref(c, ref);
1200        }
1201 out:
1202        up_write(&c->xattr_sem);
1203        jffs2_complete_reservation(c);
1204        return rc;
1205}
1206
1207/* -------- garbage collector functions -------------
1208 * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1209 *   is used to move xdatum into new node.
1210 * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1211 *   is used to move xref into new node.
1212 * jffs2_verify_xattr(c)
1213 *   is used to call do_verify_xattr_datum() before garbage collecting.
1214 * jffs2_release_xattr_datum(c, xd)
1215 *   is used to release an in-memory object of xdatum.
1216 * jffs2_release_xattr_ref(c, ref)
1217 *   is used to release an in-memory object of xref.
1218 * -------------------------------------------------- */
1219int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1220                                      struct jffs2_raw_node_ref *raw)
1221{
1222        uint32_t totlen, length, old_ofs;
1223        int rc = 0;
1224
1225        down_write(&c->xattr_sem);
1226        if (xd->node != raw)
1227                goto out;
1228        if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1229                goto out;
1230
1231        rc = load_xattr_datum(c, xd);
1232        if (unlikely(rc)) {
1233                rc = (rc > 0) ? 0 : rc;
1234                goto out;
1235        }
1236        old_ofs = ref_offset(xd->node);
1237        totlen = PAD(sizeof(struct jffs2_raw_xattr)
1238                        + xd->name_len + 1 + xd->value_len);
1239        rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1240        if (rc) {
1241                JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1242                goto out;
1243        }
1244        rc = save_xattr_datum(c, xd);
1245        if (!rc)
1246                dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1247                          xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1248 out:
1249        if (!rc)
1250                jffs2_mark_node_obsolete(c, raw);
1251        up_write(&c->xattr_sem);
1252        return rc;
1253}
1254
1255int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1256                                    struct jffs2_raw_node_ref *raw)
1257{
1258        uint32_t totlen, length, old_ofs;
1259        int rc = 0;
1260
1261        down_write(&c->xattr_sem);
1262        BUG_ON(!ref->node);
1263
1264        if (ref->node != raw)
1265                goto out;
1266        if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1267                goto out;
1268
1269        old_ofs = ref_offset(ref->node);
1270        totlen = ref_totlen(c, c->gcblock, ref->node);
1271
1272        rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1273        if (rc) {
1274                JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1275                              __func__, rc, totlen);
1276                goto out;
1277        }
1278        rc = save_xattr_ref(c, ref);
1279        if (!rc)
1280                dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1281                          ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1282 out:
1283        if (!rc)
1284                jffs2_mark_node_obsolete(c, raw);
1285        up_write(&c->xattr_sem);
1286        return rc;
1287}
1288
1289int jffs2_verify_xattr(struct jffs2_sb_info *c)
1290{
1291        struct jffs2_xattr_datum *xd, *_xd;
1292        struct jffs2_eraseblock *jeb;
1293        struct jffs2_raw_node_ref *raw;
1294        uint32_t totlen;
1295        int rc;
1296
1297        down_write(&c->xattr_sem);
1298        list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1299                rc = do_verify_xattr_datum(c, xd);
1300                if (rc < 0)
1301                        continue;
1302                list_del_init(&xd->xindex);
1303                spin_lock(&c->erase_completion_lock);
1304                for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1305                        if (ref_flags(raw) != REF_UNCHECKED)
1306                                continue;
1307                        jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1308                        totlen = PAD(ref_totlen(c, jeb, raw));
1309                        c->unchecked_size -= totlen; c->used_size += totlen;
1310                        jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1311                        raw->flash_offset = ref_offset(raw)
1312                                | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1313                }
1314                if (xd->flags & JFFS2_XFLAGS_DEAD)
1315                        list_add(&xd->xindex, &c->xattr_dead_list);
1316                spin_unlock(&c->erase_completion_lock);
1317        }
1318        up_write(&c->xattr_sem);
1319        return list_empty(&c->xattr_unchecked) ? 1 : 0;
1320}
1321
1322void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1323{
1324        /* must be called under spin_lock(&c->erase_completion_lock) */
1325        if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1326                return;
1327
1328        list_del(&xd->xindex);
1329        jffs2_free_xattr_datum(xd);
1330}
1331
1332void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1333{
1334        /* must be called under spin_lock(&c->erase_completion_lock) */
1335        struct jffs2_xattr_ref *tmp, **ptmp;
1336
1337        if (ref->node != (void *)ref)
1338                return;
1339
1340        for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1341                if (ref == tmp) {
1342                        *ptmp = tmp->next;
1343                        break;
1344                }
1345        }
1346        jffs2_free_xattr_ref(ref);
1347}
1348