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/mtd/mtd.h>
  26#include "nodelist.h"
  27/* -------- xdatum related functions ----------------
  28 * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  29 *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  30 *   the index of the xattr name/value pair cache (c->xattrindex).
  31 * is_xattr_datum_unchecked(c, xd)
  32 *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  33 *   unchecked, it returns 0.
  34 * unload_xattr_datum(c, xd)
  35 *   is used to release xattr name/value pair and detach from c->xattrindex.
  36 * reclaim_xattr_datum(c)
  37 *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  38 *   memory usage by cache is over c->xdatum_mem_threshold. Currently, this threshold
  39 *   is hard coded as 32KiB.
  40 * do_verify_xattr_datum(c, xd)
  41 *   is used to load the xdatum informations without name/value pair from the medium.
  42 *   It's necessary once, because those informations are not collected during mounting
  43 *   process when EBS is enabled.
  44 *   0 will be returned, if success. An negative return value means recoverable error, and
  45 *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  46 *   and xref when it returned positive value.
  47 * do_load_xattr_datum(c, xd)
  48 *   is used to load name/value pair from the medium.
  49 *   The meanings of return value is same as do_verify_xattr_datum().
  50 * load_xattr_datum(c, xd)
  51 *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  52 *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  53 *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  54 * save_xattr_datum(c, xd)
  55 *   is used to write xdatum to medium. xd->version will be incremented.
  56 * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  57 *   is used to create new xdatum and write to medium.
  58 * unrefer_xattr_datum(c, xd)
  59 *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
  60 *   is set on xd->flags and chained xattr_dead_list or release it immediately.
  61 *   In the first case, the garbage collector release it later.
  62 * -------------------------------------------------- */
  63static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
  64{
  65        int name_len = strlen(xname);
  66
  67        return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
  68}
  69
  70static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  71{
  72        struct jffs2_raw_node_ref *raw;
  73        int rc = 0;
  74
  75        spin_lock(&c->erase_completion_lock);
  76        for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
  77                if (ref_flags(raw) == REF_UNCHECKED) {
  78                        rc = 1;
  79                        break;
  80                }
  81        }
  82        spin_unlock(&c->erase_completion_lock);
  83        return rc;
  84}
  85
  86static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  87{
  88        /* must be called under down_write(xattr_sem) */
  89        D1(dbg_xattr("%s: xid=%u, version=%u\n", __func__, xd->xid, xd->version));
  90        if (xd->xname) {
  91                c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  92                kfree(xd->xname);
  93        }
  94
  95        list_del_init(&xd->xindex);
  96        xd->hashkey = 0;
  97        xd->xname = NULL;
  98        xd->xvalue = NULL;
  99}
 100
 101static void reclaim_xattr_datum(struct jffs2_sb_info *c)
 102{
 103        /* must be called under down_write(xattr_sem) */
 104        struct jffs2_xattr_datum *xd, *_xd;
 105        uint32_t target, before;
 106        static int index = 0;
 107        int count;
 108
 109        if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
 110                return;
 111
 112        before = c->xdatum_mem_usage;
 113        target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
 114        for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
 115                list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
 116                        if (xd->flags & JFFS2_XFLAGS_HOT) {
 117                                xd->flags &= ~JFFS2_XFLAGS_HOT;
 118                        } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
 119                                unload_xattr_datum(c, xd);
 120                        }
 121                        if (c->xdatum_mem_usage <= target)
 122                                goto out;
 123                }
 124                index = (index+1) % XATTRINDEX_HASHSIZE;
 125        }
 126 out:
 127        JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 128                     before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 129}
 130
 131static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 132{
 133        /* must be called under down_write(xattr_sem) */
 134        struct jffs2_eraseblock *jeb;
 135        struct jffs2_raw_node_ref *raw;
 136        struct jffs2_raw_xattr rx;
 137        size_t readlen;
 138        uint32_t crc, offset, totlen;
 139        int rc;
 140
 141        spin_lock(&c->erase_completion_lock);
 142        offset = ref_offset(xd->node);
 143        if (ref_flags(xd->node) == REF_PRISTINE)
 144                goto complete;
 145        spin_unlock(&c->erase_completion_lock);
 146
 147        rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
 148        if (rc || readlen != sizeof(rx)) {
 149                JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
 150                              rc, sizeof(rx), readlen, offset);
 151                return rc ? rc : -EIO;
 152        }
 153        crc = crc32(0, &rx, sizeof(rx) - 4);
 154        if (crc != je32_to_cpu(rx.node_crc)) {
 155                JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 156                            offset, je32_to_cpu(rx.hdr_crc), crc);
 157                xd->flags |= JFFS2_XFLAGS_INVALID;
 158                return JFFS2_XATTR_IS_CORRUPTED;
 159        }
 160        totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 161        if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 162            || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 163            || je32_to_cpu(rx.totlen) != totlen
 164            || je32_to_cpu(rx.xid) != xd->xid
 165            || je32_to_cpu(rx.version) != xd->version) {
 166                JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 167                            "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 168                            offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
 169                            je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
 170                            je32_to_cpu(rx.totlen), totlen,
 171                            je32_to_cpu(rx.xid), xd->xid,
 172                            je32_to_cpu(rx.version), xd->version);
 173                xd->flags |= JFFS2_XFLAGS_INVALID;
 174                return JFFS2_XATTR_IS_CORRUPTED;
 175        }
 176        xd->xprefix = rx.xprefix;
 177        xd->name_len = rx.name_len;
 178        xd->value_len = je16_to_cpu(rx.value_len);
 179        xd->data_crc = je32_to_cpu(rx.data_crc);
 180
 181        spin_lock(&c->erase_completion_lock);
 182 complete:
 183        for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
 184                jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 185                totlen = PAD(ref_totlen(c, jeb, raw));
 186                if (ref_flags(raw) == REF_UNCHECKED) {
 187                        c->unchecked_size -= totlen; c->used_size += totlen;
 188                        jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 189                }
 190                raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
 191        }
 192        spin_unlock(&c->erase_completion_lock);
 193
 194        /* unchecked xdatum is chained with c->xattr_unchecked */
 195        list_del_init(&xd->xindex);
 196
 197        dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
 198                  xd->xid, xd->version);
 199
 200        return 0;
 201}
 202
 203static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 204{
 205        /* must be called under down_write(xattr_sem) */
 206        char *data;
 207        size_t readlen;
 208        uint32_t crc, length;
 209        int i, ret, retry = 0;
 210
 211        BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 212        BUG_ON(!list_empty(&xd->xindex));
 213 retry:
 214        length = xd->name_len + 1 + xd->value_len;
 215        data = kmalloc(length, GFP_KERNEL);
 216        if (!data)
 217                return -ENOMEM;
 218
 219        ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 220                               length, &readlen, data);
 221
 222        if (ret || length!=readlen) {
 223                JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
 224                              ret, length, readlen, ref_offset(xd->node));
 225                kfree(data);
 226                return ret ? ret : -EIO;
 227        }
 228
 229        data[xd->name_len] = '\0';
 230        crc = crc32(0, data, length);
 231        if (crc != xd->data_crc) {
 232                JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XATTR)"
 233                              " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 234                              ref_offset(xd->node), xd->data_crc, crc);
 235                kfree(data);
 236                xd->flags |= JFFS2_XFLAGS_INVALID;
 237                return JFFS2_XATTR_IS_CORRUPTED;
 238        }
 239
 240        xd->flags |= JFFS2_XFLAGS_HOT;
 241        xd->xname = data;
 242        xd->xvalue = data + xd->name_len+1;
 243
 244        c->xdatum_mem_usage += length;
 245
 246        xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 247        i = xd->hashkey % XATTRINDEX_HASHSIZE;
 248        list_add(&xd->xindex, &c->xattrindex[i]);
 249        if (!retry) {
 250                retry = 1;
 251                reclaim_xattr_datum(c);
 252                if (!xd->xname)
 253                        goto retry;
 254        }
 255
 256        dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 257                  xd->xid, xd->xprefix, xd->xname);
 258
 259        return 0;
 260}
 261
 262static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 263{
 264        /* must be called under down_write(xattr_sem);
 265         * rc < 0 : recoverable error, try again
 266         * rc = 0 : success
 267         * rc > 0 : Unrecoverable error, this node should be deleted.
 268         */
 269        int rc = 0;
 270
 271        BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
 272        if (xd->xname)
 273                return 0;
 274        if (xd->flags & JFFS2_XFLAGS_INVALID)
 275                return JFFS2_XATTR_IS_CORRUPTED;
 276        if (unlikely(is_xattr_datum_unchecked(c, xd)))
 277                rc = do_verify_xattr_datum(c, xd);
 278        if (!rc)
 279                rc = do_load_xattr_datum(c, xd);
 280        return rc;
 281}
 282
 283static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 284{
 285        /* must be called under down_write(xattr_sem) */
 286        struct jffs2_raw_xattr rx;
 287        struct kvec vecs[2];
 288        size_t length;
 289        int rc, totlen;
 290        uint32_t phys_ofs = write_ofs(c);
 291
 292        BUG_ON(!xd->xname);
 293        BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
 294
 295        vecs[0].iov_base = &rx;
 296        vecs[0].iov_len = sizeof(rx);
 297        vecs[1].iov_base = xd->xname;
 298        vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 299        totlen = vecs[0].iov_len + vecs[1].iov_len;
 300
 301        /* Setup raw-xattr */
 302        memset(&rx, 0, sizeof(rx));
 303        rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 304        rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 305        rx.totlen = cpu_to_je32(PAD(totlen));
 306        rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 307
 308        rx.xid = cpu_to_je32(xd->xid);
 309        rx.version = cpu_to_je32(++xd->version);
 310        rx.xprefix = xd->xprefix;
 311        rx.name_len = xd->name_len;
 312        rx.value_len = cpu_to_je16(xd->value_len);
 313        rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 314        rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 315
 316        rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 317        if (rc || totlen != length) {
 318                JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
 319                              rc, totlen, length, phys_ofs);
 320                rc = rc ? rc : -EIO;
 321                if (length)
 322                        jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
 323
 324                return rc;
 325        }
 326        /* success */
 327        jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
 328
 329        dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 330                  xd->xid, xd->version, xd->xprefix, xd->xname);
 331
 332        return 0;
 333}
 334
 335static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 336                                                    int xprefix, const char *xname,
 337                                                    const char *xvalue, int xsize)
 338{
 339        /* must be called under down_write(xattr_sem) */
 340        struct jffs2_xattr_datum *xd;
 341        uint32_t hashkey, name_len;
 342        char *data;
 343        int i, rc;
 344
 345        /* Search xattr_datum has same xname/xvalue by index */
 346        hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 347        i = hashkey % XATTRINDEX_HASHSIZE;
 348        list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 349                if (xd->hashkey==hashkey
 350                    && xd->xprefix==xprefix
 351                    && xd->value_len==xsize
 352                    && !strcmp(xd->xname, xname)
 353                    && !memcmp(xd->xvalue, xvalue, xsize)) {
 354                        atomic_inc(&xd->refcnt);
 355                        return xd;
 356                }
 357        }
 358
 359        /* Not found, Create NEW XATTR-Cache */
 360        name_len = strlen(xname);
 361
 362        xd = jffs2_alloc_xattr_datum();
 363        if (!xd)
 364                return ERR_PTR(-ENOMEM);
 365
 366        data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 367        if (!data) {
 368                jffs2_free_xattr_datum(xd);
 369                return ERR_PTR(-ENOMEM);
 370        }
 371        strcpy(data, xname);
 372        memcpy(data + name_len + 1, xvalue, xsize);
 373
 374        atomic_set(&xd->refcnt, 1);
 375        xd->xid = ++c->highest_xid;
 376        xd->flags |= JFFS2_XFLAGS_HOT;
 377        xd->xprefix = xprefix;
 378
 379        xd->hashkey = hashkey;
 380        xd->xname = data;
 381        xd->xvalue = data + name_len + 1;
 382        xd->name_len = name_len;
 383        xd->value_len = xsize;
 384        xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 385
 386        rc = save_xattr_datum(c, xd);
 387        if (rc) {
 388                kfree(xd->xname);
 389                jffs2_free_xattr_datum(xd);
 390                return ERR_PTR(rc);
 391        }
 392
 393        /* Insert Hash Index */
 394        i = hashkey % XATTRINDEX_HASHSIZE;
 395        list_add(&xd->xindex, &c->xattrindex[i]);
 396
 397        c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 398        reclaim_xattr_datum(c);
 399
 400        return xd;
 401}
 402
 403static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 404{
 405        /* must be called under down_write(xattr_sem) */
 406        if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
 407                unload_xattr_datum(c, xd);
 408                xd->flags |= JFFS2_XFLAGS_DEAD;
 409                if (xd->node == (void *)xd) {
 410                        BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 411                        jffs2_free_xattr_datum(xd);
 412                } else {
 413                        list_add(&xd->xindex, &c->xattr_dead_list);
 414                }
 415                spin_unlock(&c->erase_completion_lock);
 416
 417                dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
 418                          xd->xid, xd->version);
 419        }
 420}
 421
 422/* -------- xref related functions ------------------
 423 * verify_xattr_ref(c, ref)
 424 *   is used to load xref information from medium. Because summary data does not
 425 *   contain xid/ino, it's necessary to verify once while mounting process.
 426 * save_xattr_ref(c, ref)
 427 *   is used to write xref to medium. If delete marker is marked, it write
 428 *   a delete marker of xref into medium.
 429 * create_xattr_ref(c, ic, xd)
 430 *   is used to create a new xref and write to medium.
 431 * delete_xattr_ref(c, ref)
 432 *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 433 *   and allows GC to reclaim those physical nodes.
 434 * jffs2_xattr_delete_inode(c, ic)
 435 *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 436 * jffs2_xattr_free_inode(c, ic)
 437 *   is called to release xattr related objects when unmounting. 
 438 * check_xattr_ref_inode(c, ic)
 439 *   is used to confirm inode does not have duplicate xattr name/value pair.
 440 * jffs2_xattr_do_crccheck_inode(c, ic)
 441 *   is used to force xattr data integrity check during the initial gc scan.
 442 * -------------------------------------------------- */
 443static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 444{
 445        struct jffs2_eraseblock *jeb;
 446        struct jffs2_raw_node_ref *raw;
 447        struct jffs2_raw_xref rr;
 448        size_t readlen;
 449        uint32_t crc, offset, totlen;
 450        int rc;
 451
 452        spin_lock(&c->erase_completion_lock);
 453        if (ref_flags(ref->node) != REF_UNCHECKED)
 454                goto complete;
 455        offset = ref_offset(ref->node);
 456        spin_unlock(&c->erase_completion_lock);
 457
 458        rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
 459        if (rc || sizeof(rr) != readlen) {
 460                JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
 461                              rc, sizeof(rr), readlen, offset);
 462                return rc ? rc : -EIO;
 463        }
 464        /* obsolete node */
 465        crc = crc32(0, &rr, sizeof(rr) - 4);
 466        if (crc != je32_to_cpu(rr.node_crc)) {
 467                JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 468                            offset, je32_to_cpu(rr.node_crc), crc);
 469                return JFFS2_XATTR_IS_CORRUPTED;
 470        }
 471        if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 472            || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 473            || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 474                JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 475                            "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
 476                            offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 477                            je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 478                            je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 479                return JFFS2_XATTR_IS_CORRUPTED;
 480        }
 481        ref->ino = je32_to_cpu(rr.ino);
 482        ref->xid = je32_to_cpu(rr.xid);
 483        ref->xseqno = je32_to_cpu(rr.xseqno);
 484        if (ref->xseqno > c->highest_xseqno)
 485                c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 486
 487        spin_lock(&c->erase_completion_lock);
 488 complete:
 489        for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
 490                jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 491                totlen = PAD(ref_totlen(c, jeb, raw));
 492                if (ref_flags(raw) == REF_UNCHECKED) {
 493                        c->unchecked_size -= totlen; c->used_size += totlen;
 494                        jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 495                }
 496                raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
 497        }
 498        spin_unlock(&c->erase_completion_lock);
 499
 500        dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 501                  ref->ino, ref->xid, ref_offset(ref->node));
 502        return 0;
 503}
 504
 505static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 506{
 507        /* must be called under down_write(xattr_sem) */
 508        struct jffs2_raw_xref rr;
 509        size_t length;
 510        uint32_t xseqno, phys_ofs = write_ofs(c);
 511        int ret;
 512
 513        rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 514        rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 515        rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 516        rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 517
 518        xseqno = (c->highest_xseqno += 2);
 519        if (is_xattr_ref_dead(ref)) {
 520                xseqno |= XREF_DELETE_MARKER;
 521                rr.ino = cpu_to_je32(ref->ino);
 522                rr.xid = cpu_to_je32(ref->xid);
 523        } else {
 524                rr.ino = cpu_to_je32(ref->ic->ino);
 525                rr.xid = cpu_to_je32(ref->xd->xid);
 526        }
 527        rr.xseqno = cpu_to_je32(xseqno);
 528        rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 529
 530        ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 531        if (ret || sizeof(rr) != length) {
 532                JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
 533                              ret, sizeof(rr), length, phys_ofs);
 534                ret = ret ? ret : -EIO;
 535                if (length)
 536                        jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
 537
 538                return ret;
 539        }
 540        /* success */
 541        ref->xseqno = xseqno;
 542        jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
 543
 544        dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 545
 546        return 0;
 547}
 548
 549static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 550                                                struct jffs2_xattr_datum *xd)
 551{
 552        /* must be called under down_write(xattr_sem) */
 553        struct jffs2_xattr_ref *ref;
 554        int ret;
 555
 556        ref = jffs2_alloc_xattr_ref();
 557        if (!ref)
 558                return ERR_PTR(-ENOMEM);
 559        ref->ic = ic;
 560        ref->xd = xd;
 561
 562        ret = save_xattr_ref(c, ref);
 563        if (ret) {
 564                jffs2_free_xattr_ref(ref);
 565                return ERR_PTR(ret);
 566        }
 567
 568        /* Chain to inode */
 569        ref->next = ic->xref;
 570        ic->xref = ref;
 571
 572        return ref; /* success */
 573}
 574
 575static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 576{
 577        /* must be called under down_write(xattr_sem) */
 578        struct jffs2_xattr_datum *xd;
 579
 580        xd = ref->xd;
 581        ref->xseqno |= XREF_DELETE_MARKER;
 582        ref->ino = ref->ic->ino;
 583        ref->xid = ref->xd->xid;
 584        spin_lock(&c->erase_completion_lock);
 585        ref->next = c->xref_dead_list;
 586        c->xref_dead_list = ref;
 587        spin_unlock(&c->erase_completion_lock);
 588
 589        dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
 590                  ref->ino, ref->xid, ref->xseqno);
 591
 592        unrefer_xattr_datum(c, xd);
 593}
 594
 595void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 596{
 597        /* It's called from jffs2_evict_inode() on inode removing.
 598           When an inode with XATTR is removed, those XATTRs must be removed. */
 599        struct jffs2_xattr_ref *ref, *_ref;
 600
 601        if (!ic || ic->pino_nlink > 0)
 602                return;
 603
 604        down_write(&c->xattr_sem);
 605        for (ref = ic->xref; ref; ref = _ref) {
 606                _ref = ref->next;
 607                delete_xattr_ref(c, ref);
 608        }
 609        ic->xref = NULL;
 610        up_write(&c->xattr_sem);
 611}
 612
 613void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 614{
 615        /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 616        struct jffs2_xattr_datum *xd;
 617        struct jffs2_xattr_ref *ref, *_ref;
 618
 619        down_write(&c->xattr_sem);
 620        for (ref = ic->xref; ref; ref = _ref) {
 621                _ref = ref->next;
 622                xd = ref->xd;
 623                if (atomic_dec_and_test(&xd->refcnt)) {
 624                        unload_xattr_datum(c, xd);
 625                        jffs2_free_xattr_datum(xd);
 626                }
 627                jffs2_free_xattr_ref(ref);
 628        }
 629        ic->xref = NULL;
 630        up_write(&c->xattr_sem);
 631}
 632
 633static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 634{
 635        /* success of check_xattr_ref_inode() means that inode (ic) dose not have
 636         * duplicate name/value pairs. If duplicate name/value pair would be found,
 637         * one will be removed.
 638         */
 639        struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 640        int rc = 0;
 641
 642        if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 643                return 0;
 644        down_write(&c->xattr_sem);
 645 retry:
 646        rc = 0;
 647        for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 648                if (!ref->xd->xname) {
 649                        rc = load_xattr_datum(c, ref->xd);
 650                        if (unlikely(rc > 0)) {
 651                                *pref = ref->next;
 652                                delete_xattr_ref(c, ref);
 653                                goto retry;
 654                        } else if (unlikely(rc < 0))
 655                                goto out;
 656                }
 657                for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 658                        if (!cmp->xd->xname) {
 659                                ref->xd->flags |= JFFS2_XFLAGS_BIND;
 660                                rc = load_xattr_datum(c, cmp->xd);
 661                                ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 662                                if (unlikely(rc > 0)) {
 663                                        *pcmp = cmp->next;
 664                                        delete_xattr_ref(c, cmp);
 665                                        goto retry;
 666                                } else if (unlikely(rc < 0))
 667                                        goto out;
 668                        }
 669                        if (ref->xd->xprefix == cmp->xd->xprefix
 670                            && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 671                                if (ref->xseqno > cmp->xseqno) {
 672                                        *pcmp = cmp->next;
 673                                        delete_xattr_ref(c, cmp);
 674                                } else {
 675                                        *pref = ref->next;
 676                                        delete_xattr_ref(c, ref);
 677                                }
 678                                goto retry;
 679                        }
 680                }
 681        }
 682        ic->flags |= INO_FLAGS_XATTR_CHECKED;
 683 out:
 684        up_write(&c->xattr_sem);
 685
 686        return rc;
 687}
 688
 689void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 690{
 691        check_xattr_ref_inode(c, ic);
 692}
 693
 694/* -------- xattr subsystem functions ---------------
 695 * jffs2_init_xattr_subsystem(c)
 696 *   is used to initialize semaphore and list_head, and some variables.
 697 * jffs2_find_xattr_datum(c, xid)
 698 *   is used to lookup xdatum while scanning process.
 699 * jffs2_clear_xattr_subsystem(c)
 700 *   is used to release any xattr related objects.
 701 * jffs2_build_xattr_subsystem(c)
 702 *   is used to associate xdatum and xref while super block building process.
 703 * jffs2_setup_xattr_datum(c, xid, version)
 704 *   is used to insert xdatum while scanning process.
 705 * -------------------------------------------------- */
 706void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 707{
 708        int i;
 709
 710        for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 711                INIT_LIST_HEAD(&c->xattrindex[i]);
 712        INIT_LIST_HEAD(&c->xattr_unchecked);
 713        INIT_LIST_HEAD(&c->xattr_dead_list);
 714        c->xref_dead_list = NULL;
 715        c->xref_temp = NULL;
 716
 717        init_rwsem(&c->xattr_sem);
 718        c->highest_xid = 0;
 719        c->highest_xseqno = 0;
 720        c->xdatum_mem_usage = 0;
 721        c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 722}
 723
 724static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 725{
 726        struct jffs2_xattr_datum *xd;
 727        int i = xid % XATTRINDEX_HASHSIZE;
 728
 729        /* It's only used in scanning/building process. */
 730        BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 731
 732        list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 733                if (xd->xid==xid)
 734                        return xd;
 735        }
 736        return NULL;
 737}
 738
 739void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 740{
 741        struct jffs2_xattr_datum *xd, *_xd;
 742        struct jffs2_xattr_ref *ref, *_ref;
 743        int i;
 744
 745        for (ref=c->xref_temp; ref; ref = _ref) {
 746                _ref = ref->next;
 747                jffs2_free_xattr_ref(ref);
 748        }
 749
 750        for (ref=c->xref_dead_list; ref; ref = _ref) {
 751                _ref = ref->next;
 752                jffs2_free_xattr_ref(ref);
 753        }
 754
 755        for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 756                list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 757                        list_del(&xd->xindex);
 758                        if (xd->xname)
 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        &jffs2_acl_access_xattr_handler,
 925        &jffs2_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 = &jffs2_acl_access_xattr_handler;
 946                break;
 947        case JFFS2_XPREFIX_ACL_DEFAULT:
 948                ret = &jffs2_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 = dentry->d_inode;
 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        ssize_t len, rc;
 971        int retry = 0;
 972
 973        rc = check_xattr_ref_inode(c, ic);
 974        if (unlikely(rc))
 975                return rc;
 976
 977        down_read(&c->xattr_sem);
 978 retry:
 979        len = 0;
 980        for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 981                BUG_ON(ref->ic != ic);
 982                xd = ref->xd;
 983                if (!xd->xname) {
 984                        /* xdatum is unchached */
 985                        if (!retry) {
 986                                retry = 1;
 987                                up_read(&c->xattr_sem);
 988                                down_write(&c->xattr_sem);
 989                                goto retry;
 990                        } else {
 991                                rc = load_xattr_datum(c, xd);
 992                                if (unlikely(rc > 0)) {
 993                                        *pref = ref->next;
 994                                        delete_xattr_ref(c, ref);
 995                                        goto retry;
 996                                } else if (unlikely(rc < 0))
 997                                        goto out;
 998                        }
 999                }
1000                xhandle = xprefix_to_handler(xd->xprefix);
1001                if (!xhandle)
1002                        continue;
1003                if (buffer) {
1004                        rc = xhandle->list(dentry, buffer+len, size-len,
1005                                           xd->xname, xd->name_len, xd->flags);
1006                } else {
1007                        rc = xhandle->list(dentry, NULL, 0, xd->xname,
1008                                           xd->name_len, xd->flags);
1009                }
1010                if (rc < 0)
1011                        goto out;
1012                len += rc;
1013        }
1014        rc = len;
1015 out:
1016        if (!retry) {
1017                up_read(&c->xattr_sem);
1018        } else {
1019                up_write(&c->xattr_sem);
1020        }
1021        return rc;
1022}
1023
1024int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1025                      char *buffer, size_t size)
1026{
1027        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1028        struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1029        struct jffs2_inode_cache *ic = f->inocache;
1030        struct jffs2_xattr_datum *xd;
1031        struct jffs2_xattr_ref *ref, **pref;
1032        int rc, retry = 0;
1033
1034        rc = check_xattr_ref_inode(c, ic);
1035        if (unlikely(rc))
1036                return rc;
1037
1038        down_read(&c->xattr_sem);
1039 retry:
1040        for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1041                BUG_ON(ref->ic!=ic);
1042
1043                xd = ref->xd;
1044                if (xd->xprefix != xprefix)
1045                        continue;
1046                if (!xd->xname) {
1047                        /* xdatum is unchached */
1048                        if (!retry) {
1049                                retry = 1;
1050                                up_read(&c->xattr_sem);
1051                                down_write(&c->xattr_sem);
1052                                goto retry;
1053                        } else {
1054                                rc = load_xattr_datum(c, xd);
1055                                if (unlikely(rc > 0)) {
1056                                        *pref = ref->next;
1057                                        delete_xattr_ref(c, ref);
1058                                        goto retry;
1059                                } else if (unlikely(rc < 0)) {
1060                                        goto out;
1061                                }
1062                        }
1063                }
1064                if (!strcmp(xname, xd->xname)) {
1065                        rc = xd->value_len;
1066                        if (buffer) {
1067                                if (size < rc) {
1068                                        rc = -ERANGE;
1069                                } else {
1070                                        memcpy(buffer, xd->xvalue, rc);
1071                                }
1072                        }
1073                        goto out;
1074                }
1075        }
1076        rc = -ENODATA;
1077 out:
1078        if (!retry) {
1079                up_read(&c->xattr_sem);
1080        } else {
1081                up_write(&c->xattr_sem);
1082        }
1083        return rc;
1084}
1085
1086int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1087                      const char *buffer, size_t size, int flags)
1088{
1089        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1090        struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1091        struct jffs2_inode_cache *ic = f->inocache;
1092        struct jffs2_xattr_datum *xd;
1093        struct jffs2_xattr_ref *ref, *newref, **pref;
1094        uint32_t length, request;
1095        int rc;
1096
1097        rc = check_xattr_ref_inode(c, ic);
1098        if (unlikely(rc))
1099                return rc;
1100
1101        request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1102        rc = jffs2_reserve_space(c, request, &length,
1103                                 ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1104        if (rc) {
1105                JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1106                return rc;
1107        }
1108
1109        /* Find existing xattr */
1110        down_write(&c->xattr_sem);
1111 retry:
1112        for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1113                xd = ref->xd;
1114                if (xd->xprefix != xprefix)
1115                        continue;
1116                if (!xd->xname) {
1117                        rc = load_xattr_datum(c, xd);
1118                        if (unlikely(rc > 0)) {
1119                                *pref = ref->next;
1120                                delete_xattr_ref(c, ref);
1121                                goto retry;
1122                        } else if (unlikely(rc < 0))
1123                                goto out;
1124                }
1125                if (!strcmp(xd->xname, xname)) {
1126                        if (flags & XATTR_CREATE) {
1127                                rc = -EEXIST;
1128                                goto out;
1129                        }
1130                        if (!buffer) {
1131                                ref->ino = ic->ino;
1132                                ref->xid = xd->xid;
1133                                ref->xseqno |= XREF_DELETE_MARKER;
1134                                rc = save_xattr_ref(c, ref);
1135                                if (!rc) {
1136                                        *pref = ref->next;
1137                                        spin_lock(&c->erase_completion_lock);
1138                                        ref->next = c->xref_dead_list;
1139                                        c->xref_dead_list = ref;
1140                                        spin_unlock(&c->erase_completion_lock);
1141                                        unrefer_xattr_datum(c, xd);
1142                                } else {
1143                                        ref->ic = ic;
1144                                        ref->xd = xd;
1145                                        ref->xseqno &= ~XREF_DELETE_MARKER;
1146                                }
1147                                goto out;
1148                        }
1149                        goto found;
1150                }
1151        }
1152        /* not found */
1153        if (flags & XATTR_REPLACE) {
1154                rc = -ENODATA;
1155                goto out;
1156        }
1157        if (!buffer) {
1158                rc = -ENODATA;
1159                goto out;
1160        }
1161 found:
1162        xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1163        if (IS_ERR(xd)) {
1164                rc = PTR_ERR(xd);
1165                goto out;
1166        }
1167        up_write(&c->xattr_sem);
1168        jffs2_complete_reservation(c);
1169
1170        /* create xattr_ref */
1171        request = PAD(sizeof(struct jffs2_raw_xref));
1172        rc = jffs2_reserve_space(c, request, &length,
1173                                 ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1174        down_write(&c->xattr_sem);
1175        if (rc) {
1176                JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1177                unrefer_xattr_datum(c, xd);
1178                up_write(&c->xattr_sem);
1179                return rc;
1180        }
1181        if (ref)
1182                *pref = ref->next;
1183        newref = create_xattr_ref(c, ic, xd);
1184        if (IS_ERR(newref)) {
1185                if (ref) {
1186                        ref->next = ic->xref;
1187                        ic->xref = ref;
1188                }
1189                rc = PTR_ERR(newref);
1190                unrefer_xattr_datum(c, xd);
1191        } else if (ref) {
1192                delete_xattr_ref(c, ref);
1193        }
1194 out:
1195        up_write(&c->xattr_sem);
1196        jffs2_complete_reservation(c);
1197        return rc;
1198}
1199
1200/* -------- garbage collector functions -------------
1201 * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1202 *   is used to move xdatum into new node.
1203 * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1204 *   is used to move xref into new node.
1205 * jffs2_verify_xattr(c)
1206 *   is used to call do_verify_xattr_datum() before garbage collecting.
1207 * jffs2_release_xattr_datum(c, xd)
1208 *   is used to release an in-memory object of xdatum.
1209 * jffs2_release_xattr_ref(c, ref)
1210 *   is used to release an in-memory object of xref.
1211 * -------------------------------------------------- */
1212int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1213                                      struct jffs2_raw_node_ref *raw)
1214{
1215        uint32_t totlen, length, old_ofs;
1216        int rc = 0;
1217
1218        down_write(&c->xattr_sem);
1219        if (xd->node != raw)
1220                goto out;
1221        if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1222                goto out;
1223
1224        rc = load_xattr_datum(c, xd);
1225        if (unlikely(rc)) {
1226                rc = (rc > 0) ? 0 : rc;
1227                goto out;
1228        }
1229        old_ofs = ref_offset(xd->node);
1230        totlen = PAD(sizeof(struct jffs2_raw_xattr)
1231                        + xd->name_len + 1 + xd->value_len);
1232        rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1233        if (rc) {
1234                JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1235                goto out;
1236        }
1237        rc = save_xattr_datum(c, xd);
1238        if (!rc)
1239                dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1240                          xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1241 out:
1242        if (!rc)
1243                jffs2_mark_node_obsolete(c, raw);
1244        up_write(&c->xattr_sem);
1245        return rc;
1246}
1247
1248int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1249                                    struct jffs2_raw_node_ref *raw)
1250{
1251        uint32_t totlen, length, old_ofs;
1252        int rc = 0;
1253
1254        down_write(&c->xattr_sem);
1255        BUG_ON(!ref->node);
1256
1257        if (ref->node != raw)
1258                goto out;
1259        if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1260                goto out;
1261
1262        old_ofs = ref_offset(ref->node);
1263        totlen = ref_totlen(c, c->gcblock, ref->node);
1264
1265        rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1266        if (rc) {
1267                JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1268                              __func__, rc, totlen);
1269                rc = rc ? rc : -EBADFD;
1270                goto out;
1271        }
1272        rc = save_xattr_ref(c, ref);
1273        if (!rc)
1274                dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1275                          ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1276 out:
1277        if (!rc)
1278                jffs2_mark_node_obsolete(c, raw);
1279        up_write(&c->xattr_sem);
1280        return rc;
1281}
1282
1283int jffs2_verify_xattr(struct jffs2_sb_info *c)
1284{
1285        struct jffs2_xattr_datum *xd, *_xd;
1286        struct jffs2_eraseblock *jeb;
1287        struct jffs2_raw_node_ref *raw;
1288        uint32_t totlen;
1289        int rc;
1290
1291        down_write(&c->xattr_sem);
1292        list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1293                rc = do_verify_xattr_datum(c, xd);
1294                if (rc < 0)
1295                        continue;
1296                list_del_init(&xd->xindex);
1297                spin_lock(&c->erase_completion_lock);
1298                for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1299                        if (ref_flags(raw) != REF_UNCHECKED)
1300                                continue;
1301                        jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1302                        totlen = PAD(ref_totlen(c, jeb, raw));
1303                        c->unchecked_size -= totlen; c->used_size += totlen;
1304                        jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1305                        raw->flash_offset = ref_offset(raw)
1306                                | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1307                }
1308                if (xd->flags & JFFS2_XFLAGS_DEAD)
1309                        list_add(&xd->xindex, &c->xattr_dead_list);
1310                spin_unlock(&c->erase_completion_lock);
1311        }
1312        up_write(&c->xattr_sem);
1313        return list_empty(&c->xattr_unchecked) ? 1 : 0;
1314}
1315
1316void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1317{
1318        /* must be called under spin_lock(&c->erase_completion_lock) */
1319        if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1320                return;
1321
1322        list_del(&xd->xindex);
1323        jffs2_free_xattr_datum(xd);
1324}
1325
1326void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1327{
1328        /* must be called under spin_lock(&c->erase_completion_lock) */
1329        struct jffs2_xattr_ref *tmp, **ptmp;
1330
1331        if (ref->node != (void *)ref)
1332                return;
1333
1334        for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1335                if (ref == tmp) {
1336                        *ptmp = tmp->next;
1337                        break;
1338                }
1339        }
1340        jffs2_free_xattr_ref(ref);
1341}
1342
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