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   1 /* -------------------------------------------------------------------------
   2  *  File: fs/jffs2/xattr.c
   3  *  XATTR support on JFFS2 FileSystem
   4  *
   5  *  Implemented by KaiGai Kohei <kaigai@ak.jp.nec.com>
   6  *  Copyright (C) 2006 NEC Corporation
   7  *
   8  *  For licensing information, see the file 'LICENCE' in the jffs2 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  * unload_xattr_datum(c, xd)
  27  *   is used to release xattr name/value pair and detach from c->xattrindex.
  28  * reclaim_xattr_datum(c)
  29  *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  30  *   memory usage by cache is over c->xdatum_mem_threshold. Currentry, this threshold
  31  *   is hard coded as 32KiB.
  32  * delete_xattr_datum_node(c, xd)
  33  *   is used to delete a jffs2 node is dominated by xdatum. When EBS(Erase Block Summary) is
  34  *   enabled, it overwrites the obsolete node by myself.
  35  * delete_xattr_datum(c, xd)
  36  *   is used to delete jffs2_xattr_datum object. It must be called with 0-value of reference
  37  *   counter. (It means how many jffs2_xattr_ref object refers this xdatum.)
  38  * do_verify_xattr_datum(c, xd)
  39  *   is used to load the xdatum informations without name/value pair from the medium.
  40  *   It's necessary once, because those informations are not collected during mounting
  41  *   process when EBS is enabled.
  42  *   0 will be returned, if success. An negative return value means recoverable error, and
  43  *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  44  *   and xref when it returned positive value.
  45  * do_load_xattr_datum(c, xd)
  46  *   is used to load name/value pair from the medium.
  47  *   The meanings of return value is same as do_verify_xattr_datum().
  48  * load_xattr_datum(c, xd)
  49  *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  50  *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  51  *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  52  * save_xattr_datum(c, xd, phys_ofs)
  53  *   is used to write xdatum to medium. xd->version will be incremented.
  54  * create_xattr_datum(c, xprefix, xname, xvalue, xsize, phys_ofs)
  55  *   is used to create new xdatum and write to medium.
  56  * -------------------------------------------------- */
  57
  58 static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
  59 {
  60         int name_len = strlen(xname);
  61
  62         return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
  63 }
  64
  65 static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  66 {
  67         /* must be called under down_write(xattr_sem) */
  68         D1(dbg_xattr("%s: xid=%u, version=%u\n", __FUNCTION__, xd->xid, xd->version));
  69         if (xd->xname) {
  70                 c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  71                 kfree(xd->xname);
  72         }
  73
  74         list_del_init(&xd->xindex);
  75         xd->hashkey = 0;
  76         xd->xname = NULL;
  77         xd->xvalue = NULL;
  78 }
  79
  80 static void reclaim_xattr_datum(struct jffs2_sb_info *c)
  81 {
  82         /* must be called under down_write(xattr_sem) */
  83         struct jffs2_xattr_datum *xd, *_xd;
  84         uint32_t target, before;
  85         static int index = 0;
  86         int count;
  87
  88         if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
  89                 return;
  90
  91         before = c->xdatum_mem_usage;
  92         target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
  93         for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
  94                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
  95                         if (xd->flags & JFFS2_XFLAGS_HOT) {
  96                                 xd->flags &= ~JFFS2_XFLAGS_HOT;
  97                         } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
  98                                 unload_xattr_datum(c, xd);
  99                         }
 100                         if (c->xdatum_mem_usage <= target)
 101                                 goto out;
 102                 }
 103                 index = (index+1) % XATTRINDEX_HASHSIZE;
 104         }
 105  out:
 106         JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 107                      before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 108 }
 109
 110 static void delete_xattr_datum_node(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 111 {
 112         /* must be called under down_write(xattr_sem) */
 113         struct jffs2_raw_xattr rx;
 114         uint32_t length;
 115         int rc;
 116
 117         if (!xd->node) {
 118                 JFFS2_WARNING("xdatum (xid=%u) is removed twice.\n", xd->xid);
 119                 return;
 120         }
 121         if (jffs2_sum_active()) {
 122                 memset(&rx, 0xff, sizeof(struct jffs2_raw_xattr));
 123                 rc = jffs2_flash_read(c, ref_offset(xd->node),
 124                                       sizeof(struct jffs2_unknown_node),
 125                                       &length, (char *)&rx);
 126                 if (rc || length != sizeof(struct jffs2_unknown_node)) {
 127                         JFFS2_ERROR("jffs2_flash_read()=%d, req=%u, read=%u at %#08x\n",
 128                                     rc, sizeof(struct jffs2_unknown_node),
 129                                     length, ref_offset(xd->node));
 130                 }
 131                 rc = jffs2_flash_write(c, ref_offset(xd->node), sizeof(rx),
 132                                        &length, (char *)&rx);
 133                 if (rc || length != sizeof(struct jffs2_raw_xattr)) {
 134                         JFFS2_ERROR("jffs2_flash_write()=%d, req=%u, wrote=%u ar %#08x\n",
 135                                     rc, sizeof(rx), length, ref_offset(xd->node));
 136                 }
 137         }
 138         spin_lock(&c->erase_completion_lock);
 139         xd->node->next_in_ino = NULL;
 140         spin_unlock(&c->erase_completion_lock);
 141         jffs2_mark_node_obsolete(c, xd->node);
 142         xd->node = NULL;
 143 }
 144
 145 static void delete_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 146 {
 147         /* must be called under down_write(xattr_sem) */
 148         BUG_ON(xd->refcnt);
 149
 150         unload_xattr_datum(c, xd);
 151         if (xd->node) {
 152                 delete_xattr_datum_node(c, xd);
 153                 xd->node = NULL;
 154         }
 155         jffs2_free_xattr_datum(xd);
 156 }
 157
 158 static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 159 {
 160         /* must be called under down_write(xattr_sem) */
 161         struct jffs2_eraseblock *jeb;
 162         struct jffs2_raw_xattr rx;
 163         size_t readlen;
 164         uint32_t crc, totlen;
 165         int rc;
 166
 167         BUG_ON(!xd->node);
 168         BUG_ON(ref_flags(xd->node) != REF_UNCHECKED);
 169
 170         rc = jffs2_flash_read(c, ref_offset(xd->node), sizeof(rx), &readlen, (char *)&rx);
 171         if (rc || readlen != sizeof(rx)) {
 172                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%u, read=%u at %#08x\n",
 173                               rc, sizeof(rx), readlen, ref_offset(xd->node));
 174                 return rc ? rc : -EIO;
 175         }
 176         crc = crc32(0, &rx, sizeof(rx) - 4);
 177         if (crc != je32_to_cpu(rx.node_crc)) {
 178                 if (je32_to_cpu(rx.node_crc) != 0xffffffff)
 179                         JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 180                                     ref_offset(xd->node), je32_to_cpu(rx.hdr_crc), crc);
 181                 return EIO;
 182         }
 183         totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 184         if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 185             || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 186             || je32_to_cpu(rx.totlen) != totlen
 187             || je32_to_cpu(rx.xid) != xd->xid
 188             || je32_to_cpu(rx.version) != xd->version) {
 189                 JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 190                             "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 191                             ref_offset(xd->node), je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
 192                             je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
 193                             je32_to_cpu(rx.totlen), totlen,
 194                             je32_to_cpu(rx.xid), xd->xid,
 195                             je32_to_cpu(rx.version), xd->version);
 196                 return EIO;
 197         }
 198         xd->xprefix = rx.xprefix;
 199         xd->name_len = rx.name_len;
 200         xd->value_len = je16_to_cpu(rx.value_len);
 201         xd->data_crc = je32_to_cpu(rx.data_crc);
 202
 203         /* This JFFS2_NODETYPE_XATTR node is checked */
 204         jeb = &c->blocks[ref_offset(xd->node) / c->sector_size];
 205         totlen = PAD(je32_to_cpu(rx.totlen));
 206
 207         spin_lock(&c->erase_completion_lock);
 208         c->unchecked_size -= totlen; c->used_size += totlen;
 209         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 210         xd->node->flash_offset = ref_offset(xd->node) | REF_PRISTINE;
 211         spin_unlock(&c->erase_completion_lock);
 212
 213         /* unchecked xdatum is chained with c->xattr_unchecked */
 214         list_del_init(&xd->xindex);
 215
 216         dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
 217                   xd->xid, xd->version);
 218
 219         return 0;
 220 }
 221
 222 static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 223 {
 224         /* must be called under down_write(xattr_sem) */
 225         char *data;
 226         size_t readlen;
 227         uint32_t crc, length;
 228         int i, ret, retry = 0;
 229
 230         BUG_ON(!xd->node);
 231         BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 232         BUG_ON(!list_empty(&xd->xindex));
 233  retry:
 234         length = xd->name_len + 1 + xd->value_len;
 235         data = kmalloc(length, GFP_KERNEL);
 236         if (!data)
 237                 return -ENOMEM;
 238
 239         ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 240                                length, &readlen, data);
 241
 242         if (ret || length!=readlen) {
 243                 JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%d, at %#08x\n",
 244                               ret, length, readlen, ref_offset(xd->node));
 245                 kfree(data);
 246                 return ret ? ret : -EIO;
 247         }
 248
 249         data[xd->name_len] = '\0';
 250         crc = crc32(0, data, length);
 251         if (crc != xd->data_crc) {
 252                 JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XREF)"
 253                               " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 254                               ref_offset(xd->node), xd->data_crc, crc);
 255                 kfree(data);
 256                 return EIO;
 257         }
 258
 259         xd->flags |= JFFS2_XFLAGS_HOT;
 260         xd->xname = data;
 261         xd->xvalue = data + xd->name_len+1;
 262
 263         c->xdatum_mem_usage += length;
 264
 265         xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 266         i = xd->hashkey % XATTRINDEX_HASHSIZE;
 267         list_add(&xd->xindex, &c->xattrindex[i]);
 268         if (!retry) {
 269                 retry = 1;
 270                 reclaim_xattr_datum(c);
 271                 if (!xd->xname)
 272                         goto retry;
 273         }
 274
 275         dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 276                   xd->xid, xd->xprefix, xd->xname);
 277
 278         return 0;
 279 }
 280
 281 static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 282 {
 283         /* must be called under down_write(xattr_sem);
 284          * rc < 0 : recoverable error, try again
 285          * rc = 0 : success
 286          * rc > 0 : Unrecoverable error, this node should be deleted.
 287          */
 288         int rc = 0;
 289         BUG_ON(xd->xname);
 290         if (!xd->node)
 291                 return EIO;
 292         if (unlikely(ref_flags(xd->node) != REF_PRISTINE)) {
 293                 rc = do_verify_xattr_datum(c, xd);
 294                 if (rc > 0) {
 295                         list_del_init(&xd->xindex);
 296                         delete_xattr_datum_node(c, xd);
 297                 }
 298         }
 299         if (!rc)
 300                 rc = do_load_xattr_datum(c, xd);
 301         return rc;
 302 }
 303
 304 static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd, uint32_t phys_ofs)
 305 {
 306         /* must be called under down_write(xattr_sem) */
 307         struct jffs2_raw_xattr rx;
 308         struct jffs2_raw_node_ref *raw;
 309         struct kvec vecs[2];
 310         uint32_t length;
 311         int rc, totlen;
 312
 313         BUG_ON(!xd->xname);
 314
 315         vecs[0].iov_base = &rx;
 316         vecs[0].iov_len = PAD(sizeof(rx));
 317         vecs[1].iov_base = xd->xname;
 318         vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 319         totlen = vecs[0].iov_len + vecs[1].iov_len;
 320
 321         raw = jffs2_alloc_raw_node_ref();
 322         if (!raw)
 323                 return -ENOMEM;
 324         raw->flash_offset = phys_ofs;
 325         raw->__totlen = PAD(totlen);
 326         raw->next_phys = NULL;
 327         raw->next_in_ino = (void *)xd;
 328
 329         /* Setup raw-xattr */
 330         rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 331         rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 332         rx.totlen = cpu_to_je32(PAD(totlen));
 333         rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 334
 335         rx.xid = cpu_to_je32(xd->xid);
 336         rx.version = cpu_to_je32(++xd->version);
 337         rx.xprefix = xd->xprefix;
 338         rx.name_len = xd->name_len;
 339         rx.value_len = cpu_to_je16(xd->value_len);
 340         rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 341         rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 342
 343         rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 344         if (rc || totlen != length) {
 345                 JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%u, at %#08x\n",
 346                               rc, totlen, length, phys_ofs);
 347                 rc = rc ? rc : -EIO;
 348                 if (length) {
 349                         raw->flash_offset |= REF_OBSOLETE;
 350                         raw->next_in_ino = NULL;
 351                         jffs2_add_physical_node_ref(c, raw);
 352                         jffs2_mark_node_obsolete(c, raw);
 353                 } else {
 354                         jffs2_free_raw_node_ref(raw);
 355                 }
 356                 return rc;
 357         }
 358         BUG_ON(raw->__totlen < sizeof(struct jffs2_raw_xattr));
 359         /* success */
 360         raw->flash_offset |= REF_PRISTINE;
 361         jffs2_add_physical_node_ref(c, raw);
 362         if (xd->node)
 363                 delete_xattr_datum_node(c, xd);
 364         xd->node = raw;
 365
 366         dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 367                   xd->xid, xd->version, xd->xprefix, xd->xname);
 368
 369         return 0;
 370 }
 371
 372 static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 373                                                     int xprefix, const char *xname,
 374                                                     const char *xvalue, int xsize,
 375                                                     uint32_t phys_ofs)
 376 {
 377         /* must be called under down_write(xattr_sem) */
 378         struct jffs2_xattr_datum *xd;
 379         uint32_t hashkey, name_len;
 380         char *data;
 381         int i, rc;
 382
 383         /* Search xattr_datum has same xname/xvalue by index */
 384         hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 385         i = hashkey % XATTRINDEX_HASHSIZE;
 386         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 387                 if (xd->hashkey==hashkey
 388                     && xd->xprefix==xprefix
 389                     && xd->value_len==xsize
 390                     && !strcmp(xd->xname, xname)
 391                     && !memcmp(xd->xvalue, xvalue, xsize)) {
 392                         xd->refcnt++;
 393                         return xd;
 394                 }
 395         }
 396
 397         /* Not found, Create NEW XATTR-Cache */
 398         name_len = strlen(xname);
 399
 400         xd = jffs2_alloc_xattr_datum();
 401         if (!xd)
 402                 return ERR_PTR(-ENOMEM);
 403
 404         data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 405         if (!data) {
 406                 jffs2_free_xattr_datum(xd);
 407                 return ERR_PTR(-ENOMEM);
 408         }
 409         strcpy(data, xname);
 410         memcpy(data + name_len + 1, xvalue, xsize);
 411
 412         xd->refcnt = 1;
 413         xd->xid = ++c->highest_xid;
 414         xd->flags |= JFFS2_XFLAGS_HOT;
 415         xd->xprefix = xprefix;
 416
 417         xd->hashkey = hashkey;
 418         xd->xname = data;
 419         xd->xvalue = data + name_len + 1;
 420         xd->name_len = name_len;
 421         xd->value_len = xsize;
 422         xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 423
 424         rc = save_xattr_datum(c, xd, phys_ofs);
 425         if (rc) {
 426                 kfree(xd->xname);
 427                 jffs2_free_xattr_datum(xd);
 428                 return ERR_PTR(rc);
 429         }
 430
 431         /* Insert Hash Index */
 432         i = hashkey % XATTRINDEX_HASHSIZE;
 433         list_add(&xd->xindex, &c->xattrindex[i]);
 434
 435         c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 436         reclaim_xattr_datum(c);
 437
 438         return xd;
 439 }
 440
 441 /* -------- xdatum related functions ----------------
 442  * verify_xattr_ref(c, ref)
 443  *   is used to load xref information from medium. Because summary data does not
 444  *   contain xid/ino, it's necessary to verify once while mounting process.
 445  * delete_xattr_ref_node(c, ref)
 446  *   is used to delete a jffs2 node is dominated by xref. When EBS is enabled,
 447  *   it overwrites the obsolete node by myself.
 448  * delete_xattr_ref(c, ref)
 449  *   is used to delete jffs2_xattr_ref object. If the reference counter of xdatum
 450  *   is refered by this xref become 0, delete_xattr_datum() is called later.
 451  * save_xattr_ref(c, ref, phys_ofs)
 452  *   is used to write xref to medium.
 453  * create_xattr_ref(c, ic, xd, phys_ofs)
 454  *   is used to create a new xref and write to medium.
 455  * jffs2_xattr_delete_inode(c, ic)
 456  *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 457  * jffs2_xattr_free_inode(c, ic)
 458  *   is called to release xattr related objects when unmounting.
 459  * check_xattr_ref_ilist(c, ic)
 460  *   is used to confirm inode does not have duplicate xattr name/value pair.
 461  * -------------------------------------------------- */
 462 static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 463 {
 464         struct jffs2_eraseblock *jeb;
 465         struct jffs2_raw_xref rr;
 466         size_t readlen;
 467         uint32_t crc, totlen;
 468         int rc;
 469
 470         BUG_ON(ref_flags(ref->node) != REF_UNCHECKED);
 471
 472         rc = jffs2_flash_read(c, ref_offset(ref->node), sizeof(rr), &readlen, (char *)&rr);
 473         if (rc || sizeof(rr) != readlen) {
 474                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%u, read=%u, at %#08x\n",
 475                               rc, sizeof(rr), readlen, ref_offset(ref->node));
 476                 return rc ? rc : -EIO;
 477         }
 478         /* obsolete node */
 479         crc = crc32(0, &rr, sizeof(rr) - 4);
 480         if (crc != je32_to_cpu(rr.node_crc)) {
 481                 if (je32_to_cpu(rr.node_crc) != 0xffffffff)
 482                         JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 483                                     ref_offset(ref->node), je32_to_cpu(rr.node_crc), crc);
 484                 return EIO;
 485         }
 486         if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 487             || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 488             || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 489                 JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 490                             "nodetype=%#04x/%#04x, totlen=%u/%u\n",
 491                             ref_offset(ref->node), je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 492                             je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 493                             je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 494                 return EIO;
 495         }
 496         ref->ino = je32_to_cpu(rr.ino);
 497         ref->xid = je32_to_cpu(rr.xid);
 498
 499         /* fixup superblock/eraseblock info */
 500         jeb = &c->blocks[ref_offset(ref->node) / c->sector_size];
 501         totlen = PAD(sizeof(rr));
 502
 503         spin_lock(&c->erase_completion_lock);
 504         c->unchecked_size -= totlen; c->used_size += totlen;
 505         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 506         ref->node->flash_offset = ref_offset(ref->node) | REF_PRISTINE;
 507         spin_unlock(&c->erase_completion_lock);
 508
 509         dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 510                   ref->ino, ref->xid, ref_offset(ref->node));
 511         return 0;
 512 }
 513
 514 static void delete_xattr_ref_node(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 515 {
 516         struct jffs2_raw_xref rr;
 517         uint32_t length;
 518         int rc;
 519
 520         if (jffs2_sum_active()) {
 521                 memset(&rr, 0xff, sizeof(rr));
 522                 rc = jffs2_flash_read(c, ref_offset(ref->node),
 523                                       sizeof(struct jffs2_unknown_node),
 524                                       &length, (char *)&rr);
 525                 if (rc || length != sizeof(struct jffs2_unknown_node)) {
 526                         JFFS2_ERROR("jffs2_flash_read()=%d, req=%u, read=%u at %#08x\n",
 527                                     rc, sizeof(struct jffs2_unknown_node),
 528                                     length, ref_offset(ref->node));
 529                 }
 530                 rc = jffs2_flash_write(c, ref_offset(ref->node), sizeof(rr),
 531                                        &length, (char *)&rr);
 532                 if (rc || length != sizeof(struct jffs2_raw_xref)) {
 533                         JFFS2_ERROR("jffs2_flash_write()=%d, req=%u, wrote=%u at %#08x\n",
 534                                     rc, sizeof(rr), length, ref_offset(ref->node));
 535                 }
 536         }
 537         spin_lock(&c->erase_completion_lock);
 538         ref->node->next_in_ino = NULL;
 539         spin_unlock(&c->erase_completion_lock);
 540         jffs2_mark_node_obsolete(c, ref->node);
 541         ref->node = NULL;
 542 }
 543
 544 static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 545 {
 546         /* must be called under down_write(xattr_sem) */
 547         struct jffs2_xattr_datum *xd;
 548
 549         BUG_ON(!ref->node);
 550         delete_xattr_ref_node(c, ref);
 551
 552         list_del(&ref->ilist);
 553         xd = ref->xd;
 554         xd->refcnt--;
 555         if (!xd->refcnt)
 556                 delete_xattr_datum(c, xd);
 557         jffs2_free_xattr_ref(ref);
 558 }
 559
 560 static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref, uint32_t phys_ofs)
 561 {
 562         /* must be called under down_write(xattr_sem) */
 563         struct jffs2_raw_node_ref *raw;
 564         struct jffs2_raw_xref rr;
 565         uint32_t length;
 566         int ret;
 567
 568         raw = jffs2_alloc_raw_node_ref();
 569         if (!raw)
 570                 return -ENOMEM;
 571         raw->flash_offset = phys_ofs;
 572         raw->__totlen = PAD(sizeof(rr));
 573         raw->next_phys = NULL;
 574         raw->next_in_ino = (void *)ref;
 575
 576         rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 577         rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 578         rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 579         rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 580
 581         rr.ino = cpu_to_je32(ref->ic->ino);
 582         rr.xid = cpu_to_je32(ref->xd->xid);
 583         rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 584
 585         ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 586         if (ret || sizeof(rr) != length) {
 587                 JFFS2_WARNING("jffs2_flash_write() returned %d, request=%u, retlen=%u, at %#08x\n",
 588                               ret, sizeof(rr), length, phys_ofs);
 589                 ret = ret ? ret : -EIO;
 590                 if (length) {
 591                         raw->flash_offset |= REF_OBSOLETE;
 592                         raw->next_in_ino = NULL;
 593                         jffs2_add_physical_node_ref(c, raw);
 594                         jffs2_mark_node_obsolete(c, raw);
 595                 } else {
 596                         jffs2_free_raw_node_ref(raw);
 597                 }
 598                 return ret;
 599         }
 600         raw->flash_offset |= REF_PRISTINE;
 601
 602         jffs2_add_physical_node_ref(c, raw);
 603         if (ref->node)
 604                 delete_xattr_ref_node(c, ref);
 605         ref->node = raw;
 606
 607         dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 608
 609         return 0;
 610 }
 611
 612 static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 613                                                 struct jffs2_xattr_datum *xd, uint32_t phys_ofs)
 614 {
 615         /* must be called under down_write(xattr_sem) */
 616         struct jffs2_xattr_ref *ref;
 617         int ret;
 618
 619         ref = jffs2_alloc_xattr_ref();
 620         if (!ref)
 621                 return ERR_PTR(-ENOMEM);
 622         ref->ic = ic;
 623         ref->xd = xd;
 624
 625         ret = save_xattr_ref(c, ref, phys_ofs);
 626         if (ret) {
 627                 jffs2_free_xattr_ref(ref);
 628                 return ERR_PTR(ret);
 629         }
 630
 631         /* Chain to inode */
 632         list_add(&ref->ilist, &ic->ilist);
 633
 634         return ref; /* success */
 635 }
 636
 637 void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 638 {
 639         /* It's called from jffs2_clear_inode() on inode removing.
 640            When an inode with XATTR is removed, those XATTRs must be removed. */
 641         struct jffs2_xattr_ref *ref, *_ref;
 642
 643         if (!ic || ic->nlink > 0)
 644                 return;
 645
 646         down_write(&c->xattr_sem);
 647         list_for_each_entry_safe(ref, _ref, &ic->ilist, ilist)
 648                 delete_xattr_ref(c, ref);
 649         up_write(&c->xattr_sem);
 650 }
 651
 652 void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 653 {
 654         /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 655         struct jffs2_xattr_datum *xd;
 656         struct jffs2_xattr_ref *ref, *_ref;
 657
 658         down_write(&c->xattr_sem);
 659         list_for_each_entry_safe(ref, _ref, &ic->ilist, ilist) {
 660                 list_del(&ref->ilist);
 661                 xd = ref->xd;
 662                 xd->refcnt--;
 663                 if (!xd->refcnt) {
 664                         unload_xattr_datum(c, xd);
 665                         jffs2_free_xattr_datum(xd);
 666                 }
 667                 jffs2_free_xattr_ref(ref);
 668         }
 669         up_write(&c->xattr_sem);
 670 }
 671
 672 static int check_xattr_ref_ilist(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 673 {
 674         /* success of check_xattr_ref_ilist() means taht inode (ic) dose not have
 675          * duplicate name/value pairs. If duplicate name/value pair would be found,
 676          * one will be removed.
 677          */
 678         struct jffs2_xattr_ref *ref, *cmp;
 679         int rc = 0;
 680
 681         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 682                 return 0;
 683         down_write(&c->xattr_sem);
 684  retry:
 685         rc = 0;
 686         list_for_each_entry(ref, &ic->ilist, ilist) {
 687                 if (!ref->xd->xname) {
 688                         rc = load_xattr_datum(c, ref->xd);
 689                         if (unlikely(rc > 0)) {
 690                                 delete_xattr_ref(c, ref);
 691                                 goto retry;
 692                         } else if (unlikely(rc < 0))
 693                                 goto out;
 694                 }
 695                 cmp = ref;
 696                 list_for_each_entry_continue(cmp, &ic->ilist, ilist) {
 697                         if (!cmp->xd->xname) {
 698                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
 699                                 rc = load_xattr_datum(c, cmp->xd);
 700                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 701                                 if (unlikely(rc > 0)) {
 702                                         delete_xattr_ref(c, cmp);
 703                                         goto retry;
 704                                 } else if (unlikely(rc < 0))
 705                                         goto out;
 706                         }
 707                         if (ref->xd->xprefix == cmp->xd->xprefix
 708                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 709                                 delete_xattr_ref(c, cmp);
 710                                 goto retry;
 711                         }
 712                 }
 713         }
 714         ic->flags |= INO_FLAGS_XATTR_CHECKED;
 715  out:
 716         up_write(&c->xattr_sem);
 717
 718         return rc;
 719 }
 720
 721 /* -------- xattr subsystem functions ---------------
 722  * jffs2_init_xattr_subsystem(c)
 723  *   is used to initialize semaphore and list_head, and some variables.
 724  * jffs2_find_xattr_datum(c, xid)
 725  *   is used to lookup xdatum while scanning process.
 726  * jffs2_clear_xattr_subsystem(c)
 727  *   is used to release any xattr related objects.
 728  * jffs2_build_xattr_subsystem(c)
 729  *   is used to associate xdatum and xref while super block building process.
 730  * jffs2_setup_xattr_datum(c, xid, version)
 731  *   is used to insert xdatum while scanning process.
 732  * -------------------------------------------------- */
 733 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 734 {
 735         int i;
 736
 737         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 738                 INIT_LIST_HEAD(&c->xattrindex[i]);
 739         INIT_LIST_HEAD(&c->xattr_temp);
 740         INIT_LIST_HEAD(&c->xattr_unchecked);
 741
 742         init_rwsem(&c->xattr_sem);
 743         c->xdatum_mem_usage = 0;
 744         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 745 }
 746
 747 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 748 {
 749         struct jffs2_xattr_datum *xd;
 750         int i = xid % XATTRINDEX_HASHSIZE;
 751
 752         /* It's only used in scanning/building process. */
 753         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 754
 755         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 756                 if (xd->xid==xid)
 757                         return xd;
 758         }
 759         return NULL;
 760 }
 761
 762 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 763 {
 764         struct jffs2_xattr_datum *xd, *_xd;
 765         struct jffs2_xattr_ref *ref, *_ref;
 766         int i;
 767
 768         list_for_each_entry_safe(ref, _ref, &c->xattr_temp, ilist)
 769                 jffs2_free_xattr_ref(ref);
 770
 771         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 772                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 773                         list_del(&xd->xindex);
 774                         if (xd->xname)
 775                                 kfree(xd->xname);
 776                         jffs2_free_xattr_datum(xd);
 777                 }
 778         }
 779 }
 780
 781 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 782 {
 783         struct jffs2_xattr_ref *ref, *_ref;
 784         struct jffs2_xattr_datum *xd, *_xd;
 785         struct jffs2_inode_cache *ic;
 786         int i, xdatum_count =0, xdatum_unchecked_count = 0, xref_count = 0;
 787
 788         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 789
 790         /* Phase.1 */
 791         list_for_each_entry_safe(ref, _ref, &c->xattr_temp, ilist) {
 792                 list_del_init(&ref->ilist);
 793                 /* checking REF_UNCHECKED nodes */
 794                 if (ref_flags(ref->node) != REF_PRISTINE) {
 795                         if (verify_xattr_ref(c, ref)) {
 796                                 delete_xattr_ref_node(c, ref);
 797                                 jffs2_free_xattr_ref(ref);
 798                                 continue;
 799                         }
 800                 }
 801                 /* At this point, ref->xid and ref->ino contain XID and inode number.
 802                    ref->xd and ref->ic are not valid yet. */
 803                 xd = jffs2_find_xattr_datum(c, ref->xid);
 804                 ic = jffs2_get_ino_cache(c, ref->ino);
 805                 if (!xd || !ic) {
 806                         if (ref_flags(ref->node) != REF_UNCHECKED)
 807                                 JFFS2_WARNING("xref(ino=%u, xid=%u) is orphan. \n",
 808                                               ref->ino, ref->xid);
 809                         delete_xattr_ref_node(c, ref);
 810                         jffs2_free_xattr_ref(ref);
 811                         continue;
 812                 }
 813                 ref->xd = xd;
 814                 ref->ic = ic;
 815                 xd->refcnt++;
 816                 list_add_tail(&ref->ilist, &ic->ilist);
 817                 xref_count++;
 818         }
 819         /* After this, ref->xid/ino are NEVER used. */
 820
 821         /* Phase.2 */
 822         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 823                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 824                         list_del_init(&xd->xindex);
 825                         if (!xd->refcnt) {
 826                                 if (ref_flags(xd->node) != REF_UNCHECKED)
 827                                         JFFS2_WARNING("orphan xdatum(xid=%u, version=%u) at %#08x\n",
 828                                                       xd->xid, xd->version, ref_offset(xd->node));
 829                                 delete_xattr_datum(c, xd);
 830                                 continue;
 831                         }
 832                         if (ref_flags(xd->node) != REF_PRISTINE) {
 833                                 dbg_xattr("unchecked xdatum(xid=%u) at %#08x\n",
 834                                           xd->xid, ref_offset(xd->node));
 835                                 list_add(&xd->xindex, &c->xattr_unchecked);
 836                                 xdatum_unchecked_count++;
 837                         }
 838                         xdatum_count++;
 839                 }
 840         }
 841         /* build complete */
 842         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum (%u unchecked) and "
 843                      "%u of xref found.\n", xdatum_count, xdatum_unchecked_count, xref_count);
 844 }
 845
 846 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 847                                                   uint32_t xid, uint32_t version)
 848 {
 849         struct jffs2_xattr_datum *xd, *_xd;
 850
 851         _xd = jffs2_find_xattr_datum(c, xid);
 852         if (_xd) {
 853                 dbg_xattr("duplicate xdatum (xid=%u, version=%u/%u) at %#08x\n",
 854                           xid, version, _xd->version, ref_offset(_xd->node));
 855                 if (version < _xd->version)
 856                         return ERR_PTR(-EEXIST);
 857         }
 858         xd = jffs2_alloc_xattr_datum();
 859         if (!xd)
 860                 return ERR_PTR(-ENOMEM);
 861         xd->xid = xid;
 862         xd->version = version;
 863         if (xd->xid > c->highest_xid)
 864                 c->highest_xid = xd->xid;
 865         list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 866
 867         if (_xd) {
 868                 list_del_init(&_xd->xindex);
 869                 delete_xattr_datum_node(c, _xd);
 870                 jffs2_free_xattr_datum(_xd);
 871         }
 872         return xd;
 873 }
 874
 875 /* -------- xattr subsystem functions ---------------
 876  * xprefix_to_handler(xprefix)
 877  *   is used to translate xprefix into xattr_handler.
 878  * jffs2_listxattr(dentry, buffer, size)
 879  *   is an implementation of listxattr handler on jffs2.
 880  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 881  *   is an implementation of getxattr handler on jffs2.
 882  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 883  *   is an implementation of setxattr handler on jffs2.
 884  * -------------------------------------------------- */
 885 struct xattr_handler *jffs2_xattr_handlers[] = {
 886         &jffs2_user_xattr_handler,
 887 #ifdef CONFIG_JFFS2_FS_SECURITY
 888         &jffs2_security_xattr_handler,
 889 #endif
 890 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 891         &jffs2_acl_access_xattr_handler,
 892         &jffs2_acl_default_xattr_handler,
 893 #endif
 894         &jffs2_trusted_xattr_handler,
 895         NULL
 896 };
 897
 898 static struct xattr_handler *xprefix_to_handler(int xprefix) {
 899         struct xattr_handler *ret;
 900
 901         switch (xprefix) {
 902         case JFFS2_XPREFIX_USER:
 903                 ret = &jffs2_user_xattr_handler;
 904                 break;
 905 #ifdef CONFIG_JFFS2_FS_SECURITY
 906         case JFFS2_XPREFIX_SECURITY:
 907                 ret = &jffs2_security_xattr_handler;
 908                 break;
 909 #endif
 910 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 911         case JFFS2_XPREFIX_ACL_ACCESS:
 912                 ret = &jffs2_acl_access_xattr_handler;
 913                 break;
 914         case JFFS2_XPREFIX_ACL_DEFAULT:
 915                 ret = &jffs2_acl_default_xattr_handler;
 916                 break;
 917 #endif
 918         case JFFS2_XPREFIX_TRUSTED:
 919                 ret = &jffs2_trusted_xattr_handler;
 920                 break;
 921         default:
 922                 ret = NULL;
 923                 break;
 924         }
 925         return ret;
 926 }
 927
 928 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 929 {
 930         struct inode *inode = dentry->d_inode;
 931         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 932         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 933         struct jffs2_inode_cache *ic = f->inocache;
 934         struct jffs2_xattr_ref *ref;
 935         struct jffs2_xattr_datum *xd;
 936         struct xattr_handler *xhandle;
 937         ssize_t len, rc;
 938         int retry = 0;
 939
 940         rc = check_xattr_ref_ilist(c, ic);
 941         if (unlikely(rc))
 942                 return rc;
 943
 944         down_read(&c->xattr_sem);
 945  retry:
 946         len = 0;
 947         list_for_each_entry(ref, &ic->ilist, ilist) {
 948                 BUG_ON(ref->ic != ic);
 949                 xd = ref->xd;
 950                 if (!xd->xname) {
 951                         /* xdatum is unchached */
 952                         if (!retry) {
 953                                 retry = 1;
 954                                 up_read(&c->xattr_sem);
 955                                 down_write(&c->xattr_sem);
 956                                 goto retry;
 957                         } else {
 958                                 rc = load_xattr_datum(c, xd);
 959                                 if (unlikely(rc > 0)) {
 960                                         delete_xattr_ref(c, ref);
 961                                         goto retry;
 962                                 } else if (unlikely(rc < 0))
 963                                         goto out;
 964                         }
 965                 }
 966                 xhandle = xprefix_to_handler(xd->xprefix);
 967                 if (!xhandle)
 968                         continue;
 969                 if (buffer) {
 970                         rc = xhandle->list(inode, buffer+len, size-len, xd->xname, xd->name_len);
 971                 } else {
 972                         rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
 973                 }
 974                 if (rc < 0)
 975                         goto out;
 976                 len += rc;
 977         }
 978         rc = len;
 979  out:
 980         if (!retry) {
 981                 up_read(&c->xattr_sem);
 982         } else {
 983                 up_write(&c->xattr_sem);
 984         }
 985         return rc;
 986 }
 987
 988 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
 989                       char *buffer, size_t size)
 990 {
 991         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 992         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 993         struct jffs2_inode_cache *ic = f->inocache;
 994         struct jffs2_xattr_datum *xd;
 995         struct jffs2_xattr_ref *ref;
 996         int rc, retry = 0;
 997
 998         rc = check_xattr_ref_ilist(c, ic);
 999         if (unlikely(rc))
1000                 return rc;
1001
1002         down_read(&c->xattr_sem);
1003  retry:
1004         list_for_each_entry(ref, &ic->ilist, ilist) {
1005                 BUG_ON(ref->ic!=ic);
1006
1007                 xd = ref->xd;
1008                 if (xd->xprefix != xprefix)
1009                         continue;
1010                 if (!xd->xname) {
1011                         /* xdatum is unchached */
1012                         if (!retry) {
1013                                 retry = 1;
1014                                 up_read(&c->xattr_sem);
1015                                 down_write(&c->xattr_sem);
1016                                 goto retry;
1017                         } else {
1018                                 rc = load_xattr_datum(c, xd);
1019                                 if (unlikely(rc > 0)) {
1020                                         delete_xattr_ref(c, ref);
1021                                         goto retry;
1022                                 } else if (unlikely(rc < 0)) {
1023                                         goto out;
1024                                 }
1025                         }
1026                 }
1027                 if (!strcmp(xname, xd->xname)) {
1028                         rc = xd->value_len;
1029                         if (buffer) {
1030                                 if (size < rc) {
1031                                         rc = -ERANGE;
1032                                 } else {
1033                                         memcpy(buffer, xd->xvalue, rc);
1034                                 }
1035                         }
1036                         goto out;
1037                 }
1038         }
1039         rc = -ENODATA;
1040  out:
1041         if (!retry) {
1042                 up_read(&c->xattr_sem);
1043         } else {
1044                 up_write(&c->xattr_sem);
1045         }
1046         return rc;
1047 }
1048
1049 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1050                       const char *buffer, size_t size, int flags)
1051 {
1052         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1053         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1054         struct jffs2_inode_cache *ic = f->inocache;
1055         struct jffs2_xattr_datum *xd;
1056         struct jffs2_xattr_ref *ref, *newref;
1057         uint32_t phys_ofs, length, request;
1058         int rc;
1059
1060         rc = check_xattr_ref_ilist(c, ic);
1061         if (unlikely(rc))
1062                 return rc;
1063
1064         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1065         rc = jffs2_reserve_space(c, request, &phys_ofs, &length,
1066                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1067         if (rc) {
1068                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1069                 return rc;
1070         }
1071
1072         /* Find existing xattr */
1073         down_write(&c->xattr_sem);
1074  retry:
1075         list_for_each_entry(ref, &ic->ilist, ilist) {
1076                 xd = ref->xd;
1077                 if (xd->xprefix != xprefix)
1078                         continue;
1079                 if (!xd->xname) {
1080                         rc = load_xattr_datum(c, xd);
1081                         if (unlikely(rc > 0)) {
1082                                 delete_xattr_ref(c, ref);
1083                                 goto retry;
1084                         } else if (unlikely(rc < 0))
1085                                 goto out;
1086                 }
1087                 if (!strcmp(xd->xname, xname)) {
1088                         if (flags & XATTR_CREATE) {
1089                                 rc = -EEXIST;
1090                                 goto out;
1091                         }
1092                         if (!buffer) {
1093                                 delete_xattr_ref(c, ref);
1094                                 rc = 0;
1095                                 goto out;
1096                         }
1097                         goto found;
1098                 }
1099         }
1100         /* not found */
1101         ref = NULL;
1102         if (flags & XATTR_REPLACE) {
1103                 rc = -ENODATA;
1104                 goto out;
1105         }
1106         if (!buffer) {
1107                 rc = -EINVAL;
1108                 goto out;
1109         }
1110  found:
1111         xd = create_xattr_datum(c, xprefix, xname, buffer, size, phys_ofs);
1112         if (IS_ERR(xd)) {
1113                 rc = PTR_ERR(xd);
1114                 goto out;
1115         }
1116         up_write(&c->xattr_sem);
1117         jffs2_complete_reservation(c);
1118
1119         /* create xattr_ref */
1120         request = PAD(sizeof(struct jffs2_raw_xref));
1121         rc = jffs2_reserve_space(c, request, &phys_ofs, &length,
1122                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1123         if (rc) {
1124                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1125                 down_write(&c->xattr_sem);
1126                 xd->refcnt--;
1127                 if (!xd->refcnt)
1128                         delete_xattr_datum(c, xd);
1129                 up_write(&c->xattr_sem);
1130                 return rc;
1131         }
1132         down_write(&c->xattr_sem);
1133         newref = create_xattr_ref(c, ic, xd, phys_ofs);
1134         if (IS_ERR(newref)) {
1135                 rc = PTR_ERR(newref);
1136                 xd->refcnt--;
1137                 if (!xd->refcnt)
1138                         delete_xattr_datum(c, xd);
1139         } else if (ref) {
1140                 /* If replaced xattr_ref exists */
1141                 delete_xattr_ref(c, ref);
1142         }
1143  out:
1144         up_write(&c->xattr_sem);
1145         jffs2_complete_reservation(c);
1146         return rc;
1147 }
1148
1149 /* -------- garbage collector functions -------------
1150  * jffs2_garbage_collect_xattr_datum(c, xd)
1151  *   is used to move xdatum into new node.
1152  * jffs2_garbage_collect_xattr_ref(c, ref)
1153  *   is used to move xref into new node.
1154  * jffs2_garbage_collect_xattr(c, ic)
1155  *   is used to call appropriate garbage collector function, if argument
1156  *   pointer (ic) is the reference of xdatum/xref.
1157  * jffs2_verify_xattr(c)
1158  *   is used to call do_verify_xattr_datum() before garbage collecting.
1159  * -------------------------------------------------- */
1160 static int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c,
1161                                              struct jffs2_xattr_datum *xd)
1162 {
1163         /* must be called under down_write(xattr_sem), and called from GC thread */
1164         uint32_t phys_ofs, totlen, length, old_ofs;
1165         int rc;
1166
1167         BUG_ON(!xd->node);
1168
1169         old_ofs = ref_offset(xd->node);
1170         totlen = ref_totlen(c, c->gcblock, xd->node);
1171         if (totlen < sizeof(struct jffs2_raw_xattr))
1172                 return -EINVAL;
1173
1174         if (!xd->xname) {
1175                 rc = load_xattr_datum(c, xd);
1176                 if (unlikely(rc > 0)) {
1177                         delete_xattr_datum_node(c, xd);
1178                         return 0;
1179                 } else if (unlikely(rc < 0))
1180                         return -EINVAL;
1181         }
1182         rc = jffs2_reserve_space_gc(c, totlen, &phys_ofs, &length, JFFS2_SUMMARY_XATTR_SIZE);
1183         if (rc || length < totlen) {
1184                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, totlen);
1185                 return rc ? rc : -EBADFD;
1186         }
1187         rc = save_xattr_datum(c, xd, phys_ofs);
1188         if (!rc)
1189                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1190                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1191         return rc;
1192 }
1193
1194
1195 static int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c,
1196                                            struct jffs2_xattr_ref *ref)
1197 {
1198         /* must be called under down(alloc_sem) */
1199         uint32_t phys_ofs, totlen, length, old_ofs;
1200         int rc;
1201
1202         BUG_ON(!ref->node);
1203
1204         old_ofs = ref_offset(ref->node);
1205         totlen = ref_totlen(c, c->gcblock, ref->node);
1206         if (totlen != sizeof(struct jffs2_raw_xref))
1207                 return -EINVAL;
1208         rc = jffs2_reserve_space_gc(c, totlen, &phys_ofs, &length, JFFS2_SUMMARY_XREF_SIZE);
1209         if (rc || length < totlen) {
1210                 JFFS2_WARNING("%s: jffs2_reserve_space() = %d, request = %u\n",
1211                               __FUNCTION__, rc, totlen);
1212                 return rc ? rc : -EBADFD;
1213         }
1214         rc = save_xattr_ref(c, ref, phys_ofs);
1215         if (!rc)
1216                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1217                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1218         return rc;
1219 }
1220
1221 int jffs2_garbage_collect_xattr(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
1222 {
1223         struct jffs2_xattr_datum *xd;
1224         struct jffs2_xattr_ref *ref;
1225         int ret;
1226
1227         switch (ic->class) {
1228         case RAWNODE_CLASS_XATTR_DATUM:
1229                 spin_unlock(&c->erase_completion_lock);
1230
1231                 down_write(&c->xattr_sem);
1232                 xd = (struct jffs2_xattr_datum *)ic;
1233                 ret = xd ? jffs2_garbage_collect_xattr_datum(c, xd) : 0;
1234                 up_write(&c->xattr_sem);
1235                 break;
1236         case RAWNODE_CLASS_XATTR_REF:
1237                 spin_unlock(&c->erase_completion_lock);
1238
1239                 down_write(&c->xattr_sem);
1240                 ref = (struct jffs2_xattr_ref *)ic;
1241                 ret = ref ? jffs2_garbage_collect_xattr_ref(c, ref) : 0;
1242                 up_write(&c->xattr_sem);
1243                 break;
1244         default:
1245                 /* This node is not xattr_datum/xattr_ref */
1246                 ret = 1;
1247                 break;
1248         }
1249         return ret;
1250 }
1251
1252 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1253 {
1254         struct jffs2_xattr_datum *xd, *_xd;
1255         int rc;
1256
1257         down_write(&c->xattr_sem);
1258         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1259                 rc = do_verify_xattr_datum(c, xd);
1260                 if (rc == 0) {
1261                         list_del_init(&xd->xindex);
1262                         break;
1263                 } else if (rc > 0) {
1264                         list_del_init(&xd->xindex);
1265                         delete_xattr_datum_node(c, xd);
1266                 }
1267         }
1268         up_write(&c->xattr_sem);
1269
1270         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1271 }