git.oblomov.eu Git - linux-2.6/blob - 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                         atomic_inc(&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         atomic_set(&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(atomic_read(&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 (atomic_dec_and_test(&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                 if (atomic_dec_and_test(&xd->refcnt)) {
 616                         unload_xattr_datum(c, xd);
 617                         jffs2_free_xattr_datum(xd);
 618                 }
 619                 jffs2_free_xattr_ref(ref);
 620         }
 621         ic->xref = NULL;
 622         up_write(&c->xattr_sem);
 623 }
 624
 625 static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 626 {
 627         /* success of check_xattr_ref_inode() means taht inode (ic) dose not have
 628          * duplicate name/value pairs. If duplicate name/value pair would be found,
 629          * one will be removed.
 630          */
 631         struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 632         int rc = 0;
 633
 634         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 635                 return 0;
 636         down_write(&c->xattr_sem);
 637  retry:
 638         rc = 0;
 639         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 640                 if (!ref->xd->xname) {
 641                         rc = load_xattr_datum(c, ref->xd);
 642                         if (unlikely(rc > 0)) {
 643                                 *pref = ref->next;
 644                                 delete_xattr_ref(c, ref);
 645                                 goto retry;
 646                         } else if (unlikely(rc < 0))
 647                                 goto out;
 648                 }
 649                 for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 650                         if (!cmp->xd->xname) {
 651                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
 652                                 rc = load_xattr_datum(c, cmp->xd);
 653                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 654                                 if (unlikely(rc > 0)) {
 655                                         *pcmp = cmp->next;
 656                                         delete_xattr_ref(c, cmp);
 657                                         goto retry;
 658                                 } else if (unlikely(rc < 0))
 659                                         goto out;
 660                         }
 661                         if (ref->xd->xprefix == cmp->xd->xprefix
 662                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 663                                 if (ref->xseqno > cmp->xseqno) {
 664                                         *pcmp = cmp->next;
 665                                         delete_xattr_ref(c, cmp);
 666                                 } else {
 667                                         *pref = ref->next;
 668                                         delete_xattr_ref(c, ref);
 669                                 }
 670                                 goto retry;
 671                         }
 672                 }
 673         }
 674         ic->flags |= INO_FLAGS_XATTR_CHECKED;
 675  out:
 676         up_write(&c->xattr_sem);
 677
 678         return rc;
 679 }
 680
 681 /* -------- xattr subsystem functions ---------------
 682  * jffs2_init_xattr_subsystem(c)
 683  *   is used to initialize semaphore and list_head, and some variables.
 684  * jffs2_find_xattr_datum(c, xid)
 685  *   is used to lookup xdatum while scanning process.
 686  * jffs2_clear_xattr_subsystem(c)
 687  *   is used to release any xattr related objects.
 688  * jffs2_build_xattr_subsystem(c)
 689  *   is used to associate xdatum and xref while super block building process.
 690  * jffs2_setup_xattr_datum(c, xid, version)
 691  *   is used to insert xdatum while scanning process.
 692  * -------------------------------------------------- */
 693 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 694 {
 695         int i;
 696
 697         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 698                 INIT_LIST_HEAD(&c->xattrindex[i]);
 699         INIT_LIST_HEAD(&c->xattr_unchecked);
 700         INIT_LIST_HEAD(&c->xattr_dead_list);
 701         c->xref_dead_list = NULL;
 702         c->xref_temp = NULL;
 703
 704         init_rwsem(&c->xattr_sem);
 705         c->highest_xid = 0;
 706         c->highest_xseqno = 0;
 707         c->xdatum_mem_usage = 0;
 708         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 709 }
 710
 711 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 712 {
 713         struct jffs2_xattr_datum *xd;
 714         int i = xid % XATTRINDEX_HASHSIZE;
 715
 716         /* It's only used in scanning/building process. */
 717         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 718
 719         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 720                 if (xd->xid==xid)
 721                         return xd;
 722         }
 723         return NULL;
 724 }
 725
 726 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 727 {
 728         struct jffs2_xattr_datum *xd, *_xd;
 729         struct jffs2_xattr_ref *ref, *_ref;
 730         int i;
 731
 732         for (ref=c->xref_temp; ref; ref = _ref) {
 733                 _ref = ref->next;
 734                 jffs2_free_xattr_ref(ref);
 735         }
 736
 737         for (ref=c->xref_dead_list; ref; ref = _ref) {
 738                 _ref = ref->next;
 739                 jffs2_free_xattr_ref(ref);
 740         }
 741
 742         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 743                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 744                         list_del(&xd->xindex);
 745                         if (xd->xname)
 746                                 kfree(xd->xname);
 747                         jffs2_free_xattr_datum(xd);
 748                 }
 749         }
 750
 751         list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
 752                 list_del(&xd->xindex);
 753                 jffs2_free_xattr_datum(xd);
 754         }
 755 }
 756
 757 #define XREF_TMPHASH_SIZE       (128)
 758 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 759 {
 760         struct jffs2_xattr_ref *ref, *_ref;
 761         struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
 762         struct jffs2_xattr_datum *xd, *_xd;
 763         struct jffs2_inode_cache *ic;
 764         struct jffs2_raw_node_ref *raw;
 765         int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
 766         int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
 767
 768         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 769
 770         /* Phase.1 : Merge same xref */
 771         for (i=0; i < XREF_TMPHASH_SIZE; i++)
 772                 xref_tmphash[i] = NULL;
 773         for (ref=c->xref_temp; ref; ref=_ref) {
 774                 struct jffs2_xattr_ref *tmp;
 775
 776                 _ref = ref->next;
 777                 if (ref_flags(ref->node) != REF_PRISTINE) {
 778                         if (verify_xattr_ref(c, ref)) {
 779                                 BUG_ON(ref->node->next_in_ino != (void *)ref);
 780                                 ref->node->next_in_ino = NULL;
 781                                 jffs2_mark_node_obsolete(c, ref->node);
 782                                 jffs2_free_xattr_ref(ref);
 783                                 continue;
 784                         }
 785                 }
 786
 787                 i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
 788                 for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
 789                         if (tmp->ino == ref->ino && tmp->xid == ref->xid)
 790                                 break;
 791                 }
 792                 if (tmp) {
 793                         raw = ref->node;
 794                         if (ref->xseqno > tmp->xseqno) {
 795                                 tmp->xseqno = ref->xseqno;
 796                                 raw->next_in_ino = tmp->node;
 797                                 tmp->node = raw;
 798                         } else {
 799                                 raw->next_in_ino = tmp->node->next_in_ino;
 800                                 tmp->node->next_in_ino = raw;
 801                         }
 802                         jffs2_free_xattr_ref(ref);
 803                         continue;
 804                 } else {
 805                         ref->next = xref_tmphash[i];
 806                         xref_tmphash[i] = ref;
 807                 }
 808         }
 809         c->xref_temp = NULL;
 810
 811         /* Phase.2 : Bind xref with inode_cache and xattr_datum */
 812         for (i=0; i < XREF_TMPHASH_SIZE; i++) {
 813                 for (ref=xref_tmphash[i]; ref; ref=_ref) {
 814                         xref_count++;
 815                         _ref = ref->next;
 816                         if (is_xattr_ref_dead(ref)) {
 817                                 ref->next = c->xref_dead_list;
 818                                 c->xref_dead_list = ref;
 819                                 xref_dead_count++;
 820                                 continue;
 821                         }
 822                         /* At this point, ref->xid and ref->ino contain XID and inode number.
 823                            ref->xd and ref->ic are not valid yet. */
 824                         xd = jffs2_find_xattr_datum(c, ref->xid);
 825                         ic = jffs2_get_ino_cache(c, ref->ino);
 826                         if (!xd || !ic) {
 827                                 dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
 828                                           ref->ino, ref->xid, ref->xseqno);
 829                                 ref->xseqno |= XREF_DELETE_MARKER;
 830                                 ref->next = c->xref_dead_list;
 831                                 c->xref_dead_list = ref;
 832                                 xref_orphan_count++;
 833                                 continue;
 834                         }
 835                         ref->xd = xd;
 836                         ref->ic = ic;
 837                         atomic_inc(&xd->refcnt);
 838                         ref->next = ic->xref;
 839                         ic->xref = ref;
 840                 }
 841         }
 842
 843         /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
 844         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 845                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 846                         xdatum_count++;
 847                         list_del_init(&xd->xindex);
 848                         if (!atomic_read(&xd->refcnt)) {
 849                                 dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
 850                                           xd->xid, xd->version);
 851                                 xd->flags |= JFFS2_XFLAGS_DEAD;
 852                                 list_add(&xd->xindex, &c->xattr_unchecked);
 853                                 xdatum_orphan_count++;
 854                                 continue;
 855                         }
 856                         if (is_xattr_datum_unchecked(c, xd)) {
 857                                 dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
 858                                           xd->xid, xd->version);
 859                                 list_add(&xd->xindex, &c->xattr_unchecked);
 860                                 xdatum_unchecked_count++;
 861                         }
 862                 }
 863         }
 864         /* build complete */
 865         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
 866                      " (%u unchecked, %u orphan) and "
 867                      "%u of xref (%u dead, %u orphan) found.\n",
 868                      xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
 869                      xref_count, xref_dead_count, xref_orphan_count);
 870 }
 871
 872 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 873                                                   uint32_t xid, uint32_t version)
 874 {
 875         struct jffs2_xattr_datum *xd;
 876
 877         xd = jffs2_find_xattr_datum(c, xid);
 878         if (!xd) {
 879                 xd = jffs2_alloc_xattr_datum();
 880                 if (!xd)
 881                         return ERR_PTR(-ENOMEM);
 882                 xd->xid = xid;
 883                 xd->version = version;
 884                 if (xd->xid > c->highest_xid)
 885                         c->highest_xid = xd->xid;
 886                 list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 887         }
 888         return xd;
 889 }
 890
 891 /* -------- xattr subsystem functions ---------------
 892  * xprefix_to_handler(xprefix)
 893  *   is used to translate xprefix into xattr_handler.
 894  * jffs2_listxattr(dentry, buffer, size)
 895  *   is an implementation of listxattr handler on jffs2.
 896  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 897  *   is an implementation of getxattr handler on jffs2.
 898  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 899  *   is an implementation of setxattr handler on jffs2.
 900  * -------------------------------------------------- */
 901 struct xattr_handler *jffs2_xattr_handlers[] = {
 902         &jffs2_user_xattr_handler,
 903 #ifdef CONFIG_JFFS2_FS_SECURITY
 904         &jffs2_security_xattr_handler,
 905 #endif
 906 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 907         &jffs2_acl_access_xattr_handler,
 908         &jffs2_acl_default_xattr_handler,
 909 #endif
 910         &jffs2_trusted_xattr_handler,
 911         NULL
 912 };
 913
 914 static struct xattr_handler *xprefix_to_handler(int xprefix) {
 915         struct xattr_handler *ret;
 916
 917         switch (xprefix) {
 918         case JFFS2_XPREFIX_USER:
 919                 ret = &jffs2_user_xattr_handler;
 920                 break;
 921 #ifdef CONFIG_JFFS2_FS_SECURITY
 922         case JFFS2_XPREFIX_SECURITY:
 923                 ret = &jffs2_security_xattr_handler;
 924                 break;
 925 #endif
 926 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 927         case JFFS2_XPREFIX_ACL_ACCESS:
 928                 ret = &jffs2_acl_access_xattr_handler;
 929                 break;
 930         case JFFS2_XPREFIX_ACL_DEFAULT:
 931                 ret = &jffs2_acl_default_xattr_handler;
 932                 break;
 933 #endif
 934         case JFFS2_XPREFIX_TRUSTED:
 935                 ret = &jffs2_trusted_xattr_handler;
 936                 break;
 937         default:
 938                 ret = NULL;
 939                 break;
 940         }
 941         return ret;
 942 }
 943
 944 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 945 {
 946         struct inode *inode = dentry->d_inode;
 947         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 948         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 949         struct jffs2_inode_cache *ic = f->inocache;
 950         struct jffs2_xattr_ref *ref, **pref;
 951         struct jffs2_xattr_datum *xd;
 952         struct xattr_handler *xhandle;
 953         ssize_t len, rc;
 954         int retry = 0;
 955
 956         rc = check_xattr_ref_inode(c, ic);
 957         if (unlikely(rc))
 958                 return rc;
 959
 960         down_read(&c->xattr_sem);
 961  retry:
 962         len = 0;
 963         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 964                 BUG_ON(ref->ic != ic);
 965                 xd = ref->xd;
 966                 if (!xd->xname) {
 967                         /* xdatum is unchached */
 968                         if (!retry) {
 969                                 retry = 1;
 970                                 up_read(&c->xattr_sem);
 971                                 down_write(&c->xattr_sem);
 972                                 goto retry;
 973                         } else {
 974                                 rc = load_xattr_datum(c, xd);
 975                                 if (unlikely(rc > 0)) {
 976                                         *pref = ref->next;
 977                                         delete_xattr_ref(c, ref);
 978                                         goto retry;
 979                                 } else if (unlikely(rc < 0))
 980                                         goto out;
 981                         }
 982                 }
 983                 xhandle = xprefix_to_handler(xd->xprefix);
 984                 if (!xhandle)
 985                         continue;
 986                 if (buffer) {
 987                         rc = xhandle->list(inode, buffer+len, size-len, xd->xname, xd->name_len);
 988                 } else {
 989                         rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
 990                 }
 991                 if (rc < 0)
 992                         goto out;
 993                 len += rc;
 994         }
 995         rc = len;
 996  out:
 997         if (!retry) {
 998                 up_read(&c->xattr_sem);
 999         } else {
1000                 up_write(&c->xattr_sem);
1001         }
1002         return rc;
1003 }
1004
1005 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1006                       char *buffer, size_t size)
1007 {
1008         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1009         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1010         struct jffs2_inode_cache *ic = f->inocache;
1011         struct jffs2_xattr_datum *xd;
1012         struct jffs2_xattr_ref *ref, **pref;
1013         int rc, retry = 0;
1014
1015         rc = check_xattr_ref_inode(c, ic);
1016         if (unlikely(rc))
1017                 return rc;
1018
1019         down_read(&c->xattr_sem);
1020  retry:
1021         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1022                 BUG_ON(ref->ic!=ic);
1023
1024                 xd = ref->xd;
1025                 if (xd->xprefix != xprefix)
1026                         continue;
1027                 if (!xd->xname) {
1028                         /* xdatum is unchached */
1029                         if (!retry) {
1030                                 retry = 1;
1031                                 up_read(&c->xattr_sem);
1032                                 down_write(&c->xattr_sem);
1033                                 goto retry;
1034                         } else {
1035                                 rc = load_xattr_datum(c, xd);
1036                                 if (unlikely(rc > 0)) {
1037                                         *pref = ref->next;
1038                                         delete_xattr_ref(c, ref);
1039                                         goto retry;
1040                                 } else if (unlikely(rc < 0)) {
1041                                         goto out;
1042                                 }
1043                         }
1044                 }
1045                 if (!strcmp(xname, xd->xname)) {
1046                         rc = xd->value_len;
1047                         if (buffer) {
1048                                 if (size < rc) {
1049                                         rc = -ERANGE;
1050                                 } else {
1051                                         memcpy(buffer, xd->xvalue, rc);
1052                                 }
1053                         }
1054                         goto out;
1055                 }
1056         }
1057         rc = -ENODATA;
1058  out:
1059         if (!retry) {
1060                 up_read(&c->xattr_sem);
1061         } else {
1062                 up_write(&c->xattr_sem);
1063         }
1064         return rc;
1065 }
1066
1067 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1068                       const char *buffer, size_t size, int flags)
1069 {
1070         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1071         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1072         struct jffs2_inode_cache *ic = f->inocache;
1073         struct jffs2_xattr_datum *xd;
1074         struct jffs2_xattr_ref *ref, *newref, **pref;
1075         uint32_t length, request;
1076         int rc;
1077
1078         rc = check_xattr_ref_inode(c, ic);
1079         if (unlikely(rc))
1080                 return rc;
1081
1082         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1083         rc = jffs2_reserve_space(c, request, &length,
1084                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1085         if (rc) {
1086                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1087                 return rc;
1088         }
1089
1090         /* Find existing xattr */
1091         down_write(&c->xattr_sem);
1092  retry:
1093         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1094                 xd = ref->xd;
1095                 if (xd->xprefix != xprefix)
1096                         continue;
1097                 if (!xd->xname) {
1098                         rc = load_xattr_datum(c, xd);
1099                         if (unlikely(rc > 0)) {
1100                                 *pref = ref->next;
1101                                 delete_xattr_ref(c, ref);
1102                                 goto retry;
1103                         } else if (unlikely(rc < 0))
1104                                 goto out;
1105                 }
1106                 if (!strcmp(xd->xname, xname)) {
1107                         if (flags & XATTR_CREATE) {
1108                                 rc = -EEXIST;
1109                                 goto out;
1110                         }
1111                         if (!buffer) {
1112                                 ref->ino = ic->ino;
1113                                 ref->xid = xd->xid;
1114                                 ref->xseqno |= XREF_DELETE_MARKER;
1115                                 rc = save_xattr_ref(c, ref);
1116                                 if (!rc) {
1117                                         *pref = ref->next;
1118                                         spin_lock(&c->erase_completion_lock);
1119                                         ref->next = c->xref_dead_list;
1120                                         c->xref_dead_list = ref;
1121                                         spin_unlock(&c->erase_completion_lock);
1122                                         if (atomic_dec_and_test(&xd->refcnt))
1123                                                 delete_xattr_datum(c, xd);
1124                                 } else {
1125                                         ref->ic = ic;
1126                                         ref->xd = xd;
1127                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1128                                 }
1129                                 goto out;
1130                         }
1131                         goto found;
1132                 }
1133         }
1134         /* not found */
1135         if (flags & XATTR_REPLACE) {
1136                 rc = -ENODATA;
1137                 goto out;
1138         }
1139         if (!buffer) {
1140                 rc = -ENODATA;
1141                 goto out;
1142         }
1143  found:
1144         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1145         if (IS_ERR(xd)) {
1146                 rc = PTR_ERR(xd);
1147                 goto out;
1148         }
1149         up_write(&c->xattr_sem);
1150         jffs2_complete_reservation(c);
1151
1152         /* create xattr_ref */
1153         request = PAD(sizeof(struct jffs2_raw_xref));
1154         rc = jffs2_reserve_space(c, request, &length,
1155                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1156         down_write(&c->xattr_sem);
1157         if (rc) {
1158                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1159                 if (atomic_dec_and_test(&xd->refcnt))
1160                         delete_xattr_datum(c, xd);
1161                 up_write(&c->xattr_sem);
1162                 return rc;
1163         }
1164         if (ref)
1165                 *pref = ref->next;
1166         newref = create_xattr_ref(c, ic, xd);
1167         if (IS_ERR(newref)) {
1168                 if (ref) {
1169                         ref->next = ic->xref;
1170                         ic->xref = ref;
1171                 }
1172                 rc = PTR_ERR(newref);
1173                 if (atomic_dec_and_test(&xd->refcnt))
1174                         delete_xattr_datum(c, xd);
1175         } else if (ref) {
1176                 delete_xattr_ref(c, ref);
1177         }
1178  out:
1179         up_write(&c->xattr_sem);
1180         jffs2_complete_reservation(c);
1181         return rc;
1182 }
1183
1184 /* -------- garbage collector functions -------------
1185  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1186  *   is used to move xdatum into new node.
1187  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1188  *   is used to move xref into new node.
1189  * jffs2_verify_xattr(c)
1190  *   is used to call do_verify_xattr_datum() before garbage collecting.
1191  * jffs2_release_xattr_datum(c, xd)
1192  *   is used to release an in-memory object of xdatum.
1193  * jffs2_release_xattr_ref(c, ref)
1194  *   is used to release an in-memory object of xref.
1195  * -------------------------------------------------- */
1196 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1197                                       struct jffs2_raw_node_ref *raw)
1198 {
1199         uint32_t totlen, length, old_ofs;
1200         int rc = 0;
1201
1202         down_write(&c->xattr_sem);
1203         if (xd->node != raw)
1204                 goto out;
1205         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1206                 goto out;
1207
1208         rc = load_xattr_datum(c, xd);
1209         if (unlikely(rc)) {
1210                 rc = (rc > 0) ? 0 : rc;
1211                 goto out;
1212         }
1213         old_ofs = ref_offset(xd->node);
1214         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1215                         + xd->name_len + 1 + xd->value_len);
1216         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1217         if (rc) {
1218                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1219                 rc = rc ? rc : -EBADFD;
1220                 goto out;
1221         }
1222         rc = save_xattr_datum(c, xd);
1223         if (!rc)
1224                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1225                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1226  out:
1227         if (!rc)
1228                 jffs2_mark_node_obsolete(c, raw);
1229         up_write(&c->xattr_sem);
1230         return rc;
1231 }
1232
1233 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1234                                     struct jffs2_raw_node_ref *raw)
1235 {
1236         uint32_t totlen, length, old_ofs;
1237         int rc = 0;
1238
1239         down_write(&c->xattr_sem);
1240         BUG_ON(!ref->node);
1241
1242         if (ref->node != raw)
1243                 goto out;
1244         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1245                 goto out;
1246
1247         old_ofs = ref_offset(ref->node);
1248         totlen = ref_totlen(c, c->gcblock, ref->node);
1249
1250         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1251         if (rc) {
1252                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1253                               __FUNCTION__, rc, totlen);
1254                 rc = rc ? rc : -EBADFD;
1255                 goto out;
1256         }
1257         rc = save_xattr_ref(c, ref);
1258         if (!rc)
1259                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1260                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1261  out:
1262         if (!rc)
1263                 jffs2_mark_node_obsolete(c, raw);
1264         up_write(&c->xattr_sem);
1265         return rc;
1266 }
1267
1268 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1269 {
1270         struct jffs2_xattr_datum *xd, *_xd;
1271         struct jffs2_eraseblock *jeb;
1272         struct jffs2_raw_node_ref *raw;
1273         uint32_t totlen;
1274         int rc;
1275
1276         down_write(&c->xattr_sem);
1277         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1278                 rc = do_verify_xattr_datum(c, xd);
1279                 if (rc < 0)
1280                         continue;
1281                 list_del_init(&xd->xindex);
1282                 spin_lock(&c->erase_completion_lock);
1283                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1284                         if (ref_flags(raw) != REF_UNCHECKED)
1285                                 continue;
1286                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1287                         totlen = PAD(ref_totlen(c, jeb, raw));
1288                         c->unchecked_size -= totlen; c->used_size += totlen;
1289                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1290                         raw->flash_offset = ref_offset(raw)
1291                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1292                 }
1293                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1294                         list_add(&xd->xindex, &c->xattr_dead_list);
1295                 spin_unlock(&c->erase_completion_lock);
1296         }
1297         up_write(&c->xattr_sem);
1298         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1299 }
1300
1301 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1302 {
1303         /* must be called under spin_lock(&c->erase_completion_lock) */
1304         if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1305                 return;
1306
1307         list_del(&xd->xindex);
1308         jffs2_free_xattr_datum(xd);
1309 }
1310
1311 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1312 {
1313         /* must be called under spin_lock(&c->erase_completion_lock) */
1314         struct jffs2_xattr_ref *tmp, **ptmp;
1315
1316         if (ref->node != (void *)ref)
1317                 return;
1318
1319         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1320                 if (ref == tmp) {
1321                         *ptmp = tmp->next;
1322                         break;
1323                 }
1324         }
1325         jffs2_free_xattr_ref(ref);
1326 }