fs/jffs2/xattr.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 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 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/fs.h>
  14 #include <linux/time.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/highmem.h>
  17 #include <linux/crc32.h>
  18 #include <linux/jffs2.h>
  19 #include <linux/xattr.h>
  20 #include <linux/mtd/mtd.h>
  21 #include "nodelist.h"
  22 /* -------- xdatum related functions ----------------
  23  * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  24  *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  25  *   the index of the xattr name/value pair cache (c->xattrindex).
  26  * is_xattr_datum_unchecked(c, xd)
  27  *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  28  *   unchecked, it returns 0.
  29  * unload_xattr_datum(c, xd)
  30  *   is used to release xattr name/value pair and detach from c->xattrindex.
  31  * reclaim_xattr_datum(c)
  32  *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  33  *   memory usage by cache is over c->xdatum_mem_threshold. Currentry, this threshold
  34  *   is hard coded as 32KiB.
  35  * do_verify_xattr_datum(c, xd)
  36  *   is used to load the xdatum informations without name/value pair from the medium.
  37  *   It's necessary once, because those informations are not collected during mounting
  38  *   process when EBS is enabled.
  39  *   0 will be returned, if success. An negative return value means recoverable error, and
  40  *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  41  *   and xref when it returned positive value.
  42  * do_load_xattr_datum(c, xd)
  43  *   is used to load name/value pair from the medium.
  44  *   The meanings of return value is same as do_verify_xattr_datum().
  45  * load_xattr_datum(c, xd)
  46  *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  47  *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  48  *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  49  * save_xattr_datum(c, xd)
  50  *   is used to write xdatum to medium. xd->version will be incremented.
  51  * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  52  *   is used to create new xdatum and write to medium.
  53  * delete_xattr_datum(c, xd)
  54  *   is used to delete a xdatum. It marks xd JFFS2_XFLAGS_DEAD, and allows
  55  *   GC to reclaim those physical nodes.
  56  * -------------------------------------------------- */
  57 static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
  58 {
  59         int name_len = strlen(xname);
  60
  61         return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
  62 }
  63
  64 static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  65 {
  66         struct jffs2_raw_node_ref *raw;
  67         int rc = 0;
  68
  69         spin_lock(&c->erase_completion_lock);
  70         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
  71                 if (ref_flags(raw) == REF_UNCHECKED) {
  72                         rc = 1;
  73                         break;
  74                 }
  75         }
  76         spin_unlock(&c->erase_completion_lock);
  77         return rc;
  78 }
  79
  80 static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  81 {
  82         /* must be called under down_write(xattr_sem) */
  83         D1(dbg_xattr("%s: xid=%u, version=%u\n", __FUNCTION__, xd->xid, xd->version));
  84         if (xd->xname) {
  85                 c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  86                 kfree(xd->xname);
  87         }
  88
  89         list_del_init(&xd->xindex);
  90         xd->hashkey = 0;
  91         xd->xname = NULL;
  92         xd->xvalue = NULL;
  93 }
  94
  95 static void reclaim_xattr_datum(struct jffs2_sb_info *c)
  96 {
  97         /* must be called under down_write(xattr_sem) */
  98         struct jffs2_xattr_datum *xd, *_xd;
  99         uint32_t target, before;
 100         static int index = 0;
 101         int count;
 102
 103         if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
 104                 return;
 105
 106         before = c->xdatum_mem_usage;
 107         target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
 108         for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
 109                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
 110                         if (xd->flags & JFFS2_XFLAGS_HOT) {
 111                                 xd->flags &= ~JFFS2_XFLAGS_HOT;
 112                         } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
 113                                 unload_xattr_datum(c, xd);
 114                         }
 115                         if (c->xdatum_mem_usage <= target)
 116                                 goto out;
 117                 }
 118                 index = (index+1) % XATTRINDEX_HASHSIZE;
 119         }
 120  out:
 121         JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 122                      before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 123 }
 124
 125 static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 126 {
 127         /* must be called under down_write(xattr_sem) */
 128         struct jffs2_eraseblock *jeb;
 129         struct jffs2_raw_node_ref *raw;
 130         struct jffs2_raw_xattr rx;
 131         size_t readlen;
 132         uint32_t crc, offset, totlen;
 133         int rc;
 134
 135         spin_lock(&c->erase_completion_lock);
 136         offset = ref_offset(xd->node);
 137         if (ref_flags(xd->node) == REF_PRISTINE)
 138                 goto complete;
 139         spin_unlock(&c->erase_completion_lock);
 140
 141         rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
 142         if (rc || readlen != sizeof(rx)) {
 143                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
 144                               rc, sizeof(rx), readlen, offset);
 145                 return rc ? rc : -EIO;
 146         }
 147         crc = crc32(0, &rx, sizeof(rx) - 4);
 148         if (crc != je32_to_cpu(rx.node_crc)) {
 149                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 150                             offset, je32_to_cpu(rx.hdr_crc), crc);
 151                 xd->flags |= JFFS2_XFLAGS_INVALID;
 152                 return EIO;
 153         }
 154         totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 155         if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 156             || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 157             || je32_to_cpu(rx.totlen) != totlen
 158             || je32_to_cpu(rx.xid) != xd->xid
 159             || je32_to_cpu(rx.version) != xd->version) {
 160                 JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 161                             "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 162                             offset, 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                 xd->flags |= JFFS2_XFLAGS_INVALID;
 168                 return EIO;
 169         }
 170         xd->xprefix = rx.xprefix;
 171         xd->name_len = rx.name_len;
 172         xd->value_len = je16_to_cpu(rx.value_len);
 173         xd->data_crc = je32_to_cpu(rx.data_crc);
 174
 175         spin_lock(&c->erase_completion_lock);
 176  complete:
 177         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
 178                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 179                 totlen = PAD(ref_totlen(c, jeb, raw));
 180                 if (ref_flags(raw) == REF_UNCHECKED) {
 181                         c->unchecked_size -= totlen; c->used_size += totlen;
 182                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 183                 }
 184                 raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
 185         }
 186         spin_unlock(&c->erase_completion_lock);
 187
 188         /* unchecked xdatum is chained with c->xattr_unchecked */
 189         list_del_init(&xd->xindex);
 190
 191         dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
 192                   xd->xid, xd->version);
 193
 194         return 0;
 195 }
 196
 197 static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 198 {
 199         /* must be called under down_write(xattr_sem) */
 200         char *data;
 201         size_t readlen;
 202         uint32_t crc, length;
 203         int i, ret, retry = 0;
 204
 205         BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 206         BUG_ON(!list_empty(&xd->xindex));
 207  retry:
 208         length = xd->name_len + 1 + xd->value_len;
 209         data = kmalloc(length, GFP_KERNEL);
 210         if (!data)
 211                 return -ENOMEM;
 212
 213         ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 214                                length, &readlen, data);
 215
 216         if (ret || length!=readlen) {
 217                 JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
 218                               ret, length, readlen, ref_offset(xd->node));
 219                 kfree(data);
 220                 return ret ? ret : -EIO;
 221         }
 222
 223         data[xd->name_len] = '\0';
 224         crc = crc32(0, data, length);
 225         if (crc != xd->data_crc) {
 226                 JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XREF)"
 227                               " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 228                               ref_offset(xd->node), xd->data_crc, crc);
 229                 kfree(data);
 230                 xd->flags |= JFFS2_XFLAGS_INVALID;
 231                 return EIO;
 232         }
 233
 234         xd->flags |= JFFS2_XFLAGS_HOT;
 235         xd->xname = data;
 236         xd->xvalue = data + xd->name_len+1;
 237
 238         c->xdatum_mem_usage += length;
 239
 240         xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 241         i = xd->hashkey % XATTRINDEX_HASHSIZE;
 242         list_add(&xd->xindex, &c->xattrindex[i]);
 243         if (!retry) {
 244                 retry = 1;
 245                 reclaim_xattr_datum(c);
 246                 if (!xd->xname)
 247                         goto retry;
 248         }
 249
 250         dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 251                   xd->xid, xd->xprefix, xd->xname);
 252
 253         return 0;
 254 }
 255
 256 static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 257 {
 258         /* must be called under down_write(xattr_sem);
 259          * rc < 0 : recoverable error, try again
 260          * rc = 0 : success
 261          * rc > 0 : Unrecoverable error, this node should be deleted.
 262          */
 263         int rc = 0;
 264
 265         BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
 266         if (xd->xname)
 267                 return 0;
 268         if (xd->flags & JFFS2_XFLAGS_INVALID)
 269                 return EIO;
 270         if (unlikely(is_xattr_datum_unchecked(c, xd)))
 271                 rc = do_verify_xattr_datum(c, xd);
 272         if (!rc)
 273                 rc = do_load_xattr_datum(c, xd);
 274         return rc;
 275 }
 276
 277 static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 278 {
 279         /* must be called under down_write(xattr_sem) */
 280         struct jffs2_raw_xattr rx;
 281         struct kvec vecs[2];
 282         size_t length;
 283         int rc, totlen;
 284         uint32_t phys_ofs = write_ofs(c);
 285
 286         BUG_ON(!xd->xname);
 287         BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
 288
 289         vecs[0].iov_base = &rx;
 290         vecs[0].iov_len = sizeof(rx);
 291         vecs[1].iov_base = xd->xname;
 292         vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 293         totlen = vecs[0].iov_len + vecs[1].iov_len;
 294
 295         /* Setup raw-xattr */
 296         memset(&rx, 0, sizeof(rx));
 297         rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 298         rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 299         rx.totlen = cpu_to_je32(PAD(totlen));
 300         rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 301
 302         rx.xid = cpu_to_je32(xd->xid);
 303         rx.version = cpu_to_je32(++xd->version);
 304         rx.xprefix = xd->xprefix;
 305         rx.name_len = xd->name_len;
 306         rx.value_len = cpu_to_je16(xd->value_len);
 307         rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 308         rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 309
 310         rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 311         if (rc || totlen != length) {
 312                 JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
 313                               rc, totlen, length, phys_ofs);
 314                 rc = rc ? rc : -EIO;
 315                 if (length)
 316                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
 317
 318                 return rc;
 319         }
 320         /* success */
 321         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
 322
 323         dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 324                   xd->xid, xd->version, xd->xprefix, xd->xname);
 325
 326         return 0;
 327 }
 328
 329 static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 330                                                     int xprefix, const char *xname,
 331                                                     const char *xvalue, int xsize)
 332 {
 333         /* must be called under down_write(xattr_sem) */
 334         struct jffs2_xattr_datum *xd;
 335         uint32_t hashkey, name_len;
 336         char *data;
 337         int i, rc;
 338
 339         /* Search xattr_datum has same xname/xvalue by index */
 340         hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 341         i = hashkey % XATTRINDEX_HASHSIZE;
 342         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 343                 if (xd->hashkey==hashkey
 344                     && xd->xprefix==xprefix
 345                     && xd->value_len==xsize
 346                     && !strcmp(xd->xname, xname)
 347                     && !memcmp(xd->xvalue, xvalue, xsize)) {
 348                         xd->refcnt++;
 349                         return xd;
 350                 }
 351         }
 352
 353         /* Not found, Create NEW XATTR-Cache */
 354         name_len = strlen(xname);
 355
 356         xd = jffs2_alloc_xattr_datum();
 357         if (!xd)
 358                 return ERR_PTR(-ENOMEM);
 359
 360         data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 361         if (!data) {
 362                 jffs2_free_xattr_datum(xd);
 363                 return ERR_PTR(-ENOMEM);
 364         }
 365         strcpy(data, xname);
 366         memcpy(data + name_len + 1, xvalue, xsize);
 367
 368         xd->refcnt = 1;
 369         xd->xid = ++c->highest_xid;
 370         xd->flags |= JFFS2_XFLAGS_HOT;
 371         xd->xprefix = xprefix;
 372
 373         xd->hashkey = hashkey;
 374         xd->xname = data;
 375         xd->xvalue = data + name_len + 1;
 376         xd->name_len = name_len;
 377         xd->value_len = xsize;
 378         xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 379
 380         rc = save_xattr_datum(c, xd);
 381         if (rc) {
 382                 kfree(xd->xname);
 383                 jffs2_free_xattr_datum(xd);
 384                 return ERR_PTR(rc);
 385         }
 386
 387         /* Insert Hash Index */
 388         i = hashkey % XATTRINDEX_HASHSIZE;
 389         list_add(&xd->xindex, &c->xattrindex[i]);
 390
 391         c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 392         reclaim_xattr_datum(c);
 393
 394         return xd;
 395 }
 396
 397 static void delete_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 398 {
 399         /* must be called under down_write(xattr_sem) */
 400         BUG_ON(xd->refcnt);
 401
 402         unload_xattr_datum(c, xd);
 403         xd->flags |= JFFS2_XFLAGS_DEAD;
 404         spin_lock(&c->erase_completion_lock);
 405         if (xd->node == (void *)xd) {
 406                 BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 407                 jffs2_free_xattr_datum(xd);
 408         } else {
 409                 list_add(&xd->xindex, &c->xattr_dead_list);
 410         }
 411         spin_unlock(&c->erase_completion_lock);
 412         dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n", xd->xid, xd->version);
 413 }
 414
 415 /* -------- xref related functions ------------------
 416  * verify_xattr_ref(c, ref)
 417  *   is used to load xref information from medium. Because summary data does not
 418  *   contain xid/ino, it's necessary to verify once while mounting process.
 419  * save_xattr_ref(c, ref)
 420  *   is used to write xref to medium. If delete marker is marked, it write
 421  *   a delete marker of xref into medium.
 422  * create_xattr_ref(c, ic, xd)
 423  *   is used to create a new xref and write to medium.
 424  * delete_xattr_ref(c, ref)
 425  *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 426  *   and allows GC to reclaim those physical nodes.
 427  * jffs2_xattr_delete_inode(c, ic)
 428  *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 429  * jffs2_xattr_free_inode(c, ic)
 430  *   is called to release xattr related objects when unmounting.
 431  * check_xattr_ref_inode(c, ic)
 432  *   is used to confirm inode does not have duplicate xattr name/value pair.
 433  * -------------------------------------------------- */
 434 static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 435 {
 436         struct jffs2_eraseblock *jeb;
 437         struct jffs2_raw_node_ref *raw;
 438         struct jffs2_raw_xref rr;
 439         size_t readlen;
 440         uint32_t crc, offset, totlen;
 441         int rc;
 442
 443         spin_lock(&c->erase_completion_lock);
 444         if (ref_flags(ref->node) != REF_UNCHECKED)
 445                 goto complete;
 446         offset = ref_offset(ref->node);
 447         spin_unlock(&c->erase_completion_lock);
 448
 449         rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
 450         if (rc || sizeof(rr) != readlen) {
 451                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
 452                               rc, sizeof(rr), readlen, offset);
 453                 return rc ? rc : -EIO;
 454         }
 455         /* obsolete node */
 456         crc = crc32(0, &rr, sizeof(rr) - 4);
 457         if (crc != je32_to_cpu(rr.node_crc)) {
 458                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 459                             offset, je32_to_cpu(rr.node_crc), crc);
 460                 return EIO;
 461         }
 462         if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 463             || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 464             || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 465                 JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 466                             "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
 467                             offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 468                             je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 469                             je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 470                 return EIO;
 471         }
 472         ref->ino = je32_to_cpu(rr.ino);
 473         ref->xid = je32_to_cpu(rr.xid);
 474         ref->xseqno = je32_to_cpu(rr.xseqno);
 475         if (ref->xseqno > c->highest_xseqno)
 476                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 477
 478         spin_lock(&c->erase_completion_lock);
 479  complete:
 480         for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
 481                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 482                 totlen = PAD(ref_totlen(c, jeb, raw));
 483                 if (ref_flags(raw) == REF_UNCHECKED) {
 484                         c->unchecked_size -= totlen; c->used_size += totlen;
 485                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 486                 }
 487                 raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
 488         }
 489         spin_unlock(&c->erase_completion_lock);
 490
 491         dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 492                   ref->ino, ref->xid, ref_offset(ref->node));
 493         return 0;
 494 }
 495
 496 static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 497 {
 498         /* must be called under down_write(xattr_sem) */
 499         struct jffs2_raw_xref rr;
 500         size_t length;
 501         uint32_t xseqno, phys_ofs = write_ofs(c);
 502         int ret;
 503
 504         rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 505         rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 506         rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 507         rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 508
 509         xseqno = (c->highest_xseqno += 2);
 510         if (is_xattr_ref_dead(ref)) {
 511                 xseqno |= XREF_DELETE_MARKER;
 512                 rr.ino = cpu_to_je32(ref->ino);
 513                 rr.xid = cpu_to_je32(ref->xid);
 514         } else {
 515                 rr.ino = cpu_to_je32(ref->ic->ino);
 516                 rr.xid = cpu_to_je32(ref->xd->xid);
 517         }
 518         rr.xseqno = cpu_to_je32(xseqno);
 519         rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 520
 521         ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 522         if (ret || sizeof(rr) != length) {
 523                 JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
 524                               ret, sizeof(rr), length, phys_ofs);
 525                 ret = ret ? ret : -EIO;
 526                 if (length)
 527                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
 528
 529                 return ret;
 530         }
 531         /* success */
 532         ref->xseqno = xseqno;
 533         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
 534
 535         dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 536
 537         return 0;
 538 }
 539
 540 static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 541                                                 struct jffs2_xattr_datum *xd)
 542 {
 543         /* must be called under down_write(xattr_sem) */
 544         struct jffs2_xattr_ref *ref;
 545         int ret;
 546
 547         ref = jffs2_alloc_xattr_ref();
 548         if (!ref)
 549                 return ERR_PTR(-ENOMEM);
 550         ref->ic = ic;
 551         ref->xd = xd;
 552
 553         ret = save_xattr_ref(c, ref);
 554         if (ret) {
 555                 jffs2_free_xattr_ref(ref);
 556                 return ERR_PTR(ret);
 557         }
 558
 559         /* Chain to inode */
 560         ref->next = ic->xref;
 561         ic->xref = ref;
 562
 563         return ref; /* success */
 564 }
 565
 566 static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 567 {
 568         /* must be called under down_write(xattr_sem) */
 569         struct jffs2_xattr_datum *xd;
 570
 571         xd = ref->xd;
 572         ref->xseqno |= XREF_DELETE_MARKER;
 573         ref->ino = ref->ic->ino;
 574         ref->xid = ref->xd->xid;
 575         spin_lock(&c->erase_completion_lock);
 576         ref->next = c->xref_dead_list;
 577         c->xref_dead_list = ref;
 578         spin_unlock(&c->erase_completion_lock);
 579
 580         dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
 581                   ref->ino, ref->xid, ref->xseqno);
 582
 583         if (!--xd->refcnt)
 584                 delete_xattr_datum(c, xd);
 585 }
 586
 587 void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 588 {
 589         /* It's called from jffs2_clear_inode() on inode removing.
 590            When an inode with XATTR is removed, those XATTRs must be removed. */
 591         struct jffs2_xattr_ref *ref, *_ref;
 592
 593         if (!ic || ic->nlink > 0)
 594                 return;
 595
 596         down_write(&c->xattr_sem);
 597         for (ref = ic->xref; ref; ref = _ref) {
 598                 _ref = ref->next;
 599                 delete_xattr_ref(c, ref);
 600         }
 601         ic->xref = NULL;
 602         up_write(&c->xattr_sem);
 603 }
 604
 605 void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 606 {
 607         /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 608         struct jffs2_xattr_datum *xd;
 609         struct jffs2_xattr_ref *ref, *_ref;
 610
 611         down_write(&c->xattr_sem);
 612         for (ref = ic->xref; ref; ref = _ref) {
 613                 _ref = ref->next;
 614                 xd = ref->xd;
 615                 xd->refcnt--;
 616                 if (!xd->refcnt) {
 617                         unload_xattr_datum(c, xd);
 618                         jffs2_free_xattr_datum(xd);
 619                 }
 620                 jffs2_free_xattr_ref(ref);
 621         }
 622         ic->xref = NULL;
 623         up_write(&c->xattr_sem);
 624 }
 625
 626 static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 627 {
 628         /* success of check_xattr_ref_inode() means taht inode (ic) dose not have
 629          * duplicate name/value pairs. If duplicate name/value pair would be found,
 630          * one will be removed.
 631          */
 632         struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 633         int rc = 0;
 634
 635         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 636                 return 0;
 637         down_write(&c->xattr_sem);
 638  retry:
 639         rc = 0;
 640         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 641                 if (!ref->xd->xname) {
 642                         rc = load_xattr_datum(c, ref->xd);
 643                         if (unlikely(rc > 0)) {
 644                                 *pref = ref->next;
 645                                 delete_xattr_ref(c, ref);
 646                                 goto retry;
 647                         } else if (unlikely(rc < 0))
 648                                 goto out;
 649                 }
 650                 for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 651                         if (!cmp->xd->xname) {
 652                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
 653                                 rc = load_xattr_datum(c, cmp->xd);
 654                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 655                                 if (unlikely(rc > 0)) {
 656                                         *pcmp = cmp->next;
 657                                         delete_xattr_ref(c, cmp);
 658                                         goto retry;
 659                                 } else if (unlikely(rc < 0))
 660                                         goto out;
 661                         }
 662                         if (ref->xd->xprefix == cmp->xd->xprefix
 663                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 664                                 if (ref->xseqno > cmp->xseqno) {
 665                                         *pcmp = cmp->next;
 666                                         delete_xattr_ref(c, cmp);
 667                                 } else {
 668                                         *pref = ref->next;
 669                                         delete_xattr_ref(c, ref);
 670                                 }
 671                                 goto retry;
 672                         }
 673                 }
 674         }
 675         ic->flags |= INO_FLAGS_XATTR_CHECKED;
 676  out:
 677         up_write(&c->xattr_sem);
 678
 679         return rc;
 680 }
 681
 682 /* -------- xattr subsystem functions ---------------
 683  * jffs2_init_xattr_subsystem(c)
 684  *   is used to initialize semaphore and list_head, and some variables.
 685  * jffs2_find_xattr_datum(c, xid)
 686  *   is used to lookup xdatum while scanning process.
 687  * jffs2_clear_xattr_subsystem(c)
 688  *   is used to release any xattr related objects.
 689  * jffs2_build_xattr_subsystem(c)
 690  *   is used to associate xdatum and xref while super block building process.
 691  * jffs2_setup_xattr_datum(c, xid, version)
 692  *   is used to insert xdatum while scanning process.
 693  * -------------------------------------------------- */
 694 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 695 {
 696         int i;
 697
 698         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 699                 INIT_LIST_HEAD(&c->xattrindex[i]);
 700         INIT_LIST_HEAD(&c->xattr_unchecked);
 701         INIT_LIST_HEAD(&c->xattr_dead_list);
 702         c->xref_dead_list = NULL;
 703         c->xref_temp = NULL;
 704
 705         init_rwsem(&c->xattr_sem);
 706         c->highest_xid = 0;
 707         c->highest_xseqno = 0;
 708         c->xdatum_mem_usage = 0;
 709         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 710 }
 711
 712 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 713 {
 714         struct jffs2_xattr_datum *xd;
 715         int i = xid % XATTRINDEX_HASHSIZE;
 716
 717         /* It's only used in scanning/building process. */
 718         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 719
 720         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 721                 if (xd->xid==xid)
 722                         return xd;
 723         }
 724         return NULL;
 725 }
 726
 727 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 728 {
 729         struct jffs2_xattr_datum *xd, *_xd;
 730         struct jffs2_xattr_ref *ref, *_ref;
 731         int i;
 732
 733         for (ref=c->xref_temp; ref; ref = _ref) {
 734                 _ref = ref->next;
 735                 jffs2_free_xattr_ref(ref);
 736         }
 737
 738         for (ref=c->xref_dead_list; ref; ref = _ref) {
 739                 _ref = ref->next;
 740                 jffs2_free_xattr_ref(ref);
 741         }
 742
 743         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 744                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 745                         list_del(&xd->xindex);
 746                         if (xd->xname)
 747                                 kfree(xd->xname);
 748                         jffs2_free_xattr_datum(xd);
 749                 }
 750         }
 751
 752         list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
 753                 list_del(&xd->xindex);
 754                 jffs2_free_xattr_datum(xd);
 755         }
 756 }
 757
 758 #define XREF_TMPHASH_SIZE       (128)
 759 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 760 {
 761         struct jffs2_xattr_ref *ref, *_ref;
 762         struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
 763         struct jffs2_xattr_datum *xd, *_xd;
 764         struct jffs2_inode_cache *ic;
 765         struct jffs2_raw_node_ref *raw;
 766         int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
 767         int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
 768
 769         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 770
 771         /* Phase.1 : Merge same xref */
 772         for (i=0; i < XREF_TMPHASH_SIZE; i++)
 773                 xref_tmphash[i] = NULL;
 774         for (ref=c->xref_temp; ref; ref=_ref) {
 775                 struct jffs2_xattr_ref *tmp;
 776
 777                 _ref = ref->next;
 778                 if (ref_flags(ref->node) != REF_PRISTINE) {
 779                         if (verify_xattr_ref(c, ref)) {
 780                                 BUG_ON(ref->node->next_in_ino != (void *)ref);
 781                                 ref->node->next_in_ino = NULL;
 782                                 jffs2_mark_node_obsolete(c, ref->node);
 783                                 jffs2_free_xattr_ref(ref);
 784                                 continue;
 785                         }
 786                 }
 787
 788                 i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
 789                 for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
 790                         if (tmp->ino == ref->ino && tmp->xid == ref->xid)
 791                                 break;
 792                 }
 793                 if (tmp) {
 794                         raw = ref->node;
 795                         if (ref->xseqno > tmp->xseqno) {
 796                                 tmp->xseqno = ref->xseqno;
 797                                 raw->next_in_ino = tmp->node;
 798                                 tmp->node = raw;
 799                         } else {
 800                                 raw->next_in_ino = tmp->node->next_in_ino;
 801                                 tmp->node->next_in_ino = raw;
 802                         }
 803                         jffs2_free_xattr_ref(ref);
 804                         continue;
 805                 } else {
 806                         ref->next = xref_tmphash[i];
 807                         xref_tmphash[i] = ref;
 808                 }
 809         }
 810         c->xref_temp = NULL;
 811
 812         /* Phase.2 : Bind xref with inode_cache and xattr_datum */
 813         for (i=0; i < XREF_TMPHASH_SIZE; i++) {
 814                 for (ref=xref_tmphash[i]; ref; ref=_ref) {
 815                         xref_count++;
 816                         _ref = ref->next;
 817                         if (is_xattr_ref_dead(ref)) {
 818                                 ref->next = c->xref_dead_list;
 819                                 c->xref_dead_list = ref;
 820                                 xref_dead_count++;
 821                                 continue;
 822                         }
 823                         /* At this point, ref->xid and ref->ino contain XID and inode number.
 824                            ref->xd and ref->ic are not valid yet. */
 825                         xd = jffs2_find_xattr_datum(c, ref->xid);
 826                         ic = jffs2_get_ino_cache(c, ref->ino);
 827                         if (!xd || !ic) {
 828                                 dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
 829                                           ref->ino, ref->xid, ref->xseqno);
 830                                 ref->xseqno |= XREF_DELETE_MARKER;
 831                                 ref->next = c->xref_dead_list;
 832                                 c->xref_dead_list = ref;
 833                                 xref_orphan_count++;
 834                                 continue;
 835                         }
 836                         ref->xd = xd;
 837                         ref->ic = ic;
 838                         xd->refcnt++;
 839                         ref->next = ic->xref;
 840                         ic->xref = ref;
 841                 }
 842         }
 843
 844         /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
 845         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 846                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 847                         xdatum_count++;
 848                         list_del_init(&xd->xindex);
 849                         if (!xd->refcnt) {
 850                                 dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
 851                                           xd->xid, xd->version);
 852                                 xd->flags |= JFFS2_XFLAGS_DEAD;
 853                                 list_add(&xd->xindex, &c->xattr_unchecked);
 854                                 xdatum_orphan_count++;
 855                                 continue;
 856                         }
 857                         if (is_xattr_datum_unchecked(c, xd)) {
 858                                 dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
 859                                           xd->xid, xd->version);
 860                                 list_add(&xd->xindex, &c->xattr_unchecked);
 861                                 xdatum_unchecked_count++;
 862                         }
 863                 }
 864         }
 865         /* build complete */
 866         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
 867                      " (%u unchecked, %u orphan) and "
 868                      "%u of xref (%u dead, %u orphan) found.\n",
 869                      xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
 870                      xref_count, xref_dead_count, xref_orphan_count);
 871 }
 872
 873 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 874                                                   uint32_t xid, uint32_t version)
 875 {
 876         struct jffs2_xattr_datum *xd;
 877
 878         xd = jffs2_find_xattr_datum(c, xid);
 879         if (!xd) {
 880                 xd = jffs2_alloc_xattr_datum();
 881                 if (!xd)
 882                         return ERR_PTR(-ENOMEM);
 883                 xd->xid = xid;
 884                 xd->version = version;
 885                 if (xd->xid > c->highest_xid)
 886                         c->highest_xid = xd->xid;
 887                 list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 888         }
 889         return xd;
 890 }
 891
 892 /* -------- xattr subsystem functions ---------------
 893  * xprefix_to_handler(xprefix)
 894  *   is used to translate xprefix into xattr_handler.
 895  * jffs2_listxattr(dentry, buffer, size)
 896  *   is an implementation of listxattr handler on jffs2.
 897  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 898  *   is an implementation of getxattr handler on jffs2.
 899  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 900  *   is an implementation of setxattr handler on jffs2.
 901  * -------------------------------------------------- */
 902 struct xattr_handler *jffs2_xattr_handlers[] = {
 903         &jffs2_user_xattr_handler,
 904 #ifdef CONFIG_JFFS2_FS_SECURITY
 905         &jffs2_security_xattr_handler,
 906 #endif
 907 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 908         &jffs2_acl_access_xattr_handler,
 909         &jffs2_acl_default_xattr_handler,
 910 #endif
 911         &jffs2_trusted_xattr_handler,
 912         NULL
 913 };
 914
 915 static struct xattr_handler *xprefix_to_handler(int xprefix) {
 916         struct xattr_handler *ret;
 917
 918         switch (xprefix) {
 919         case JFFS2_XPREFIX_USER:
 920                 ret = &jffs2_user_xattr_handler;
 921                 break;
 922 #ifdef CONFIG_JFFS2_FS_SECURITY
 923         case JFFS2_XPREFIX_SECURITY:
 924                 ret = &jffs2_security_xattr_handler;
 925                 break;
 926 #endif
 927 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 928         case JFFS2_XPREFIX_ACL_ACCESS:
 929                 ret = &jffs2_acl_access_xattr_handler;
 930                 break;
 931         case JFFS2_XPREFIX_ACL_DEFAULT:
 932                 ret = &jffs2_acl_default_xattr_handler;
 933                 break;
 934 #endif
 935         case JFFS2_XPREFIX_TRUSTED:
 936                 ret = &jffs2_trusted_xattr_handler;
 937                 break;
 938         default:
 939                 ret = NULL;
 940                 break;
 941         }
 942         return ret;
 943 }
 944
 945 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 946 {
 947         struct inode *inode = dentry->d_inode;
 948         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 949         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 950         struct jffs2_inode_cache *ic = f->inocache;
 951         struct jffs2_xattr_ref *ref, **pref;
 952         struct jffs2_xattr_datum *xd;
 953         struct xattr_handler *xhandle;
 954         ssize_t len, rc;
 955         int retry = 0;
 956
 957         rc = check_xattr_ref_inode(c, ic);
 958         if (unlikely(rc))
 959                 return rc;
 960
 961         down_read(&c->xattr_sem);
 962  retry:
 963         len = 0;
 964         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 965                 BUG_ON(ref->ic != ic);
 966                 xd = ref->xd;
 967                 if (!xd->xname) {
 968                         /* xdatum is unchached */
 969                         if (!retry) {
 970                                 retry = 1;
 971                                 up_read(&c->xattr_sem);
 972                                 down_write(&c->xattr_sem);
 973                                 goto retry;
 974                         } else {
 975                                 rc = load_xattr_datum(c, xd);
 976                                 if (unlikely(rc > 0)) {
 977                                         *pref = ref->next;
 978                                         delete_xattr_ref(c, ref);
 979                                         goto retry;
 980                                 } else if (unlikely(rc < 0))
 981                                         goto out;
 982                         }
 983                 }
 984                 xhandle = xprefix_to_handler(xd->xprefix);
 985                 if (!xhandle)
 986                         continue;
 987                 if (buffer) {
 988                         rc = xhandle->list(inode, buffer+len, size-len, xd->xname, xd->name_len);
 989                 } else {
 990                         rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
 991                 }
 992                 if (rc < 0)
 993                         goto out;
 994                 len += rc;
 995         }
 996         rc = len;
 997  out:
 998         if (!retry) {
 999                 up_read(&c->xattr_sem);
1000         } else {
1001                 up_write(&c->xattr_sem);
1002         }
1003         return rc;
1004 }
1005
1006 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1007                       char *buffer, size_t size)
1008 {
1009         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1010         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1011         struct jffs2_inode_cache *ic = f->inocache;
1012         struct jffs2_xattr_datum *xd;
1013         struct jffs2_xattr_ref *ref, **pref;
1014         int rc, retry = 0;
1015
1016         rc = check_xattr_ref_inode(c, ic);
1017         if (unlikely(rc))
1018                 return rc;
1019
1020         down_read(&c->xattr_sem);
1021  retry:
1022         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1023                 BUG_ON(ref->ic!=ic);
1024
1025                 xd = ref->xd;
1026                 if (xd->xprefix != xprefix)
1027                         continue;
1028                 if (!xd->xname) {
1029                         /* xdatum is unchached */
1030                         if (!retry) {
1031                                 retry = 1;
1032                                 up_read(&c->xattr_sem);
1033                                 down_write(&c->xattr_sem);
1034                                 goto retry;
1035                         } else {
1036                                 rc = load_xattr_datum(c, xd);
1037                                 if (unlikely(rc > 0)) {
1038                                         *pref = ref->next;
1039                                         delete_xattr_ref(c, ref);
1040                                         goto retry;
1041                                 } else if (unlikely(rc < 0)) {
1042                                         goto out;
1043                                 }
1044                         }
1045                 }
1046                 if (!strcmp(xname, xd->xname)) {
1047                         rc = xd->value_len;
1048                         if (buffer) {
1049                                 if (size < rc) {
1050                                         rc = -ERANGE;
1051                                 } else {
1052                                         memcpy(buffer, xd->xvalue, rc);
1053                                 }
1054                         }
1055                         goto out;
1056                 }
1057         }
1058         rc = -ENODATA;
1059  out:
1060         if (!retry) {
1061                 up_read(&c->xattr_sem);
1062         } else {
1063                 up_write(&c->xattr_sem);
1064         }
1065         return rc;
1066 }
1067
1068 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1069                       const char *buffer, size_t size, int flags)
1070 {
1071         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1072         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1073         struct jffs2_inode_cache *ic = f->inocache;
1074         struct jffs2_xattr_datum *xd;
1075         struct jffs2_xattr_ref *ref, *newref, **pref;
1076         uint32_t length, request;
1077         int rc;
1078
1079         rc = check_xattr_ref_inode(c, ic);
1080         if (unlikely(rc))
1081                 return rc;
1082
1083         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1084         rc = jffs2_reserve_space(c, request, &length,
1085                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1086         if (rc) {
1087                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1088                 return rc;
1089         }
1090
1091         /* Find existing xattr */
1092         down_write(&c->xattr_sem);
1093  retry:
1094         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1095                 xd = ref->xd;
1096                 if (xd->xprefix != xprefix)
1097                         continue;
1098                 if (!xd->xname) {
1099                         rc = load_xattr_datum(c, xd);
1100                         if (unlikely(rc > 0)) {
1101                                 *pref = ref->next;
1102                                 delete_xattr_ref(c, ref);
1103                                 goto retry;
1104                         } else if (unlikely(rc < 0))
1105                                 goto out;
1106                 }
1107                 if (!strcmp(xd->xname, xname)) {
1108                         if (flags & XATTR_CREATE) {
1109                                 rc = -EEXIST;
1110                                 goto out;
1111                         }
1112                         if (!buffer) {
1113                                 ref->ino = ic->ino;
1114                                 ref->xid = xd->xid;
1115                                 ref->xseqno |= XREF_DELETE_MARKER;
1116                                 rc = save_xattr_ref(c, ref);
1117                                 if (!rc) {
1118                                         *pref = ref->next;
1119                                         spin_lock(&c->erase_completion_lock);
1120                                         ref->next = c->xref_dead_list;
1121                                         c->xref_dead_list = ref;
1122                                         spin_unlock(&c->erase_completion_lock);
1123                                         if (!--xd->refcnt)
1124                                                 delete_xattr_datum(c, xd);
1125                                 } else {
1126                                         ref->ic = ic;
1127                                         ref->xd = xd;
1128                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1129                                 }
1130                                 goto out;
1131                         }
1132                         goto found;
1133                 }
1134         }
1135         /* not found */
1136         if (flags & XATTR_REPLACE) {
1137                 rc = -ENODATA;
1138                 goto out;
1139         }
1140         if (!buffer) {
1141                 rc = -ENODATA;
1142                 goto out;
1143         }
1144  found:
1145         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1146         if (IS_ERR(xd)) {
1147                 rc = PTR_ERR(xd);
1148                 goto out;
1149         }
1150         up_write(&c->xattr_sem);
1151         jffs2_complete_reservation(c);
1152
1153         /* create xattr_ref */
1154         request = PAD(sizeof(struct jffs2_raw_xref));
1155         rc = jffs2_reserve_space(c, request, &length,
1156                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1157         down_write(&c->xattr_sem);
1158         if (rc) {
1159                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1160                 xd->refcnt--;
1161                 if (!xd->refcnt)
1162                         delete_xattr_datum(c, xd);
1163                 up_write(&c->xattr_sem);
1164                 return rc;
1165         }
1166         if (ref)
1167                 *pref = ref->next;
1168         newref = create_xattr_ref(c, ic, xd);
1169         if (IS_ERR(newref)) {
1170                 if (ref) {
1171                         ref->next = ic->xref;
1172                         ic->xref = ref;
1173                 }
1174                 rc = PTR_ERR(newref);
1175                 xd->refcnt--;
1176                 if (!xd->refcnt)
1177                         delete_xattr_datum(c, xd);
1178         } else if (ref) {
1179                 delete_xattr_ref(c, ref);
1180         }
1181  out:
1182         up_write(&c->xattr_sem);
1183         jffs2_complete_reservation(c);
1184         return rc;
1185 }
1186
1187 /* -------- garbage collector functions -------------
1188  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1189  *   is used to move xdatum into new node.
1190  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1191  *   is used to move xref into new node.
1192  * jffs2_verify_xattr(c)
1193  *   is used to call do_verify_xattr_datum() before garbage collecting.
1194  * jffs2_release_xattr_datum(c, xd)
1195  *   is used to release an in-memory object of xdatum.
1196  * jffs2_release_xattr_ref(c, ref)
1197  *   is used to release an in-memory object of xref.
1198  * -------------------------------------------------- */
1199 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1200                                       struct jffs2_raw_node_ref *raw)
1201 {
1202         uint32_t totlen, length, old_ofs;
1203         int rc = 0;
1204
1205         down_write(&c->xattr_sem);
1206         if (xd->node != raw)
1207                 goto out;
1208         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1209                 goto out;
1210
1211         rc = load_xattr_datum(c, xd);
1212         if (unlikely(rc)) {
1213                 rc = (rc > 0) ? 0 : rc;
1214                 goto out;
1215         }
1216         old_ofs = ref_offset(xd->node);
1217         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1218                         + xd->name_len + 1 + xd->value_len);
1219         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1220         if (rc) {
1221                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1222                 rc = rc ? rc : -EBADFD;
1223                 goto out;
1224         }
1225         rc = save_xattr_datum(c, xd);
1226         if (!rc)
1227                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1228                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1229  out:
1230         if (!rc)
1231                 jffs2_mark_node_obsolete(c, raw);
1232         up_write(&c->xattr_sem);
1233         return rc;
1234 }
1235
1236 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1237                                     struct jffs2_raw_node_ref *raw)
1238 {
1239         uint32_t totlen, length, old_ofs;
1240         int rc = 0;
1241
1242         down_write(&c->xattr_sem);
1243         BUG_ON(!ref->node);
1244
1245         if (ref->node != raw)
1246                 goto out;
1247         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1248                 goto out;
1249
1250         old_ofs = ref_offset(ref->node);
1251         totlen = ref_totlen(c, c->gcblock, ref->node);
1252
1253         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1254         if (rc) {
1255                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1256                               __FUNCTION__, rc, totlen);
1257                 rc = rc ? rc : -EBADFD;
1258                 goto out;
1259         }
1260         rc = save_xattr_ref(c, ref);
1261         if (!rc)
1262                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1263                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1264  out:
1265         if (!rc)
1266                 jffs2_mark_node_obsolete(c, raw);
1267         up_write(&c->xattr_sem);
1268         return rc;
1269 }
1270
1271 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1272 {
1273         struct jffs2_xattr_datum *xd, *_xd;
1274         struct jffs2_eraseblock *jeb;
1275         struct jffs2_raw_node_ref *raw;
1276         uint32_t totlen;
1277         int rc;
1278
1279         down_write(&c->xattr_sem);
1280         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1281                 rc = do_verify_xattr_datum(c, xd);
1282                 if (rc < 0)
1283                         continue;
1284                 list_del_init(&xd->xindex);
1285                 spin_lock(&c->erase_completion_lock);
1286                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1287                         if (ref_flags(raw) != REF_UNCHECKED)
1288                                 continue;
1289                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1290                         totlen = PAD(ref_totlen(c, jeb, raw));
1291                         c->unchecked_size -= totlen; c->used_size += totlen;
1292                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1293                         raw->flash_offset = ref_offset(raw)
1294                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1295                 }
1296                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1297                         list_add(&xd->xindex, &c->xattr_dead_list);
1298                 spin_unlock(&c->erase_completion_lock);
1299         }
1300         up_write(&c->xattr_sem);
1301         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1302 }
1303
1304 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1305 {
1306         /* must be called under spin_lock(&c->erase_completion_lock) */
1307         if (xd->refcnt > 0 || xd->node != (void *)xd)
1308                 return;
1309
1310         list_del(&xd->xindex);
1311         jffs2_free_xattr_datum(xd);
1312 }
1313
1314 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1315 {
1316         /* must be called under spin_lock(&c->erase_completion_lock) */
1317         struct jffs2_xattr_ref *tmp, **ptmp;
1318
1319         if (ref->node != (void *)ref)
1320                 return;
1321
1322         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1323                 if (ref == tmp) {
1324                         *ptmp = tmp->next;
1325                         break;
1326                 }
1327         }
1328         jffs2_free_xattr_ref(ref);
1329 }