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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_inode(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         xd = ref->xd;
 553         xd->refcnt--;
 554         if (!xd->refcnt)
 555                 delete_xattr_datum(c, xd);
 556         jffs2_free_xattr_ref(ref);
 557 }
 558
 559 static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref, uint32_t phys_ofs)
 560 {
 561         /* must be called under down_write(xattr_sem) */
 562         struct jffs2_raw_node_ref *raw;
 563         struct jffs2_raw_xref rr;
 564         uint32_t length;
 565         int ret;
 566
 567         raw = jffs2_alloc_raw_node_ref();
 568         if (!raw)
 569                 return -ENOMEM;
 570         raw->flash_offset = phys_ofs;
 571         raw->__totlen = PAD(sizeof(rr));
 572         raw->next_phys = NULL;
 573         raw->next_in_ino = (void *)ref;
 574
 575         rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 576         rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 577         rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 578         rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 579
 580         rr.ino = cpu_to_je32(ref->ic->ino);
 581         rr.xid = cpu_to_je32(ref->xd->xid);
 582         rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 583
 584         ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 585         if (ret || sizeof(rr) != length) {
 586                 JFFS2_WARNING("jffs2_flash_write() returned %d, request=%u, retlen=%u, at %#08x\n",
 587                               ret, sizeof(rr), length, phys_ofs);
 588                 ret = ret ? ret : -EIO;
 589                 if (length) {
 590                         raw->flash_offset |= REF_OBSOLETE;
 591                         raw->next_in_ino = NULL;
 592                         jffs2_add_physical_node_ref(c, raw);
 593                         jffs2_mark_node_obsolete(c, raw);
 594                 } else {
 595                         jffs2_free_raw_node_ref(raw);
 596                 }
 597                 return ret;
 598         }
 599         raw->flash_offset |= REF_PRISTINE;
 600
 601         jffs2_add_physical_node_ref(c, raw);
 602         if (ref->node)
 603                 delete_xattr_ref_node(c, ref);
 604         ref->node = raw;
 605
 606         dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 607
 608         return 0;
 609 }
 610
 611 static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 612                                                 struct jffs2_xattr_datum *xd, uint32_t phys_ofs)
 613 {
 614         /* must be called under down_write(xattr_sem) */
 615         struct jffs2_xattr_ref *ref;
 616         int ret;
 617
 618         ref = jffs2_alloc_xattr_ref();
 619         if (!ref)
 620                 return ERR_PTR(-ENOMEM);
 621         ref->ic = ic;
 622         ref->xd = xd;
 623
 624         ret = save_xattr_ref(c, ref, phys_ofs);
 625         if (ret) {
 626                 jffs2_free_xattr_ref(ref);
 627                 return ERR_PTR(ret);
 628         }
 629
 630         /* Chain to inode */
 631         ref->next = ic->xref;
 632         ic->xref = ref;
 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         for (ref = ic->xref; ref; ref = _ref) {
 648                 _ref = ref->next;
 649                 delete_xattr_ref(c, ref);
 650         }
 651         ic->xref = NULL;
 652         up_write(&c->xattr_sem);
 653 }
 654
 655 void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 656 {
 657         /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 658         struct jffs2_xattr_datum *xd;
 659         struct jffs2_xattr_ref *ref, *_ref;
 660
 661         down_write(&c->xattr_sem);
 662         for (ref = ic->xref; ref; ref = _ref) {
 663                 _ref = ref->next;
 664                 xd = ref->xd;
 665                 xd->refcnt--;
 666                 if (!xd->refcnt) {
 667                         unload_xattr_datum(c, xd);
 668                         jffs2_free_xattr_datum(xd);
 669                 }
 670                 jffs2_free_xattr_ref(ref);
 671         }
 672         ic->xref = NULL;
 673         up_write(&c->xattr_sem);
 674 }
 675
 676 static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 677 {
 678         /* success of check_xattr_ref_inode() means taht inode (ic) dose not have
 679          * duplicate name/value pairs. If duplicate name/value pair would be found,
 680          * one will be removed.
 681          */
 682         struct jffs2_xattr_ref *ref, *cmp, **pref;
 683         int rc = 0;
 684
 685         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 686                 return 0;
 687         down_write(&c->xattr_sem);
 688  retry:
 689         rc = 0;
 690         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 691                 if (!ref->xd->xname) {
 692                         rc = load_xattr_datum(c, ref->xd);
 693                         if (unlikely(rc > 0)) {
 694                                 *pref = ref->next;
 695                                 delete_xattr_ref(c, ref);
 696                                 goto retry;
 697                         } else if (unlikely(rc < 0))
 698                                 goto out;
 699                 }
 700                 for (cmp=ref->next, pref=&ref->next; cmp; pref=&cmp->next, cmp=cmp->next) {
 701                         if (!cmp->xd->xname) {
 702                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
 703                                 rc = load_xattr_datum(c, cmp->xd);
 704                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 705                                 if (unlikely(rc > 0)) {
 706                                         *pref = cmp->next;
 707                                         delete_xattr_ref(c, cmp);
 708                                         goto retry;
 709                                 } else if (unlikely(rc < 0))
 710                                         goto out;
 711                         }
 712                         if (ref->xd->xprefix == cmp->xd->xprefix
 713                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 714                                 *pref = cmp->next;
 715                                 delete_xattr_ref(c, cmp);
 716                                 goto retry;
 717                         }
 718                 }
 719         }
 720         ic->flags |= INO_FLAGS_XATTR_CHECKED;
 721  out:
 722         up_write(&c->xattr_sem);
 723
 724         return rc;
 725 }
 726
 727 /* -------- xattr subsystem functions ---------------
 728  * jffs2_init_xattr_subsystem(c)
 729  *   is used to initialize semaphore and list_head, and some variables.
 730  * jffs2_find_xattr_datum(c, xid)
 731  *   is used to lookup xdatum while scanning process.
 732  * jffs2_clear_xattr_subsystem(c)
 733  *   is used to release any xattr related objects.
 734  * jffs2_build_xattr_subsystem(c)
 735  *   is used to associate xdatum and xref while super block building process.
 736  * jffs2_setup_xattr_datum(c, xid, version)
 737  *   is used to insert xdatum while scanning process.
 738  * -------------------------------------------------- */
 739 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 740 {
 741         int i;
 742
 743         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 744                 INIT_LIST_HEAD(&c->xattrindex[i]);
 745         INIT_LIST_HEAD(&c->xattr_unchecked);
 746         c->xref_temp = NULL;
 747
 748         init_rwsem(&c->xattr_sem);
 749         c->xdatum_mem_usage = 0;
 750         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 751 }
 752
 753 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 754 {
 755         struct jffs2_xattr_datum *xd;
 756         int i = xid % XATTRINDEX_HASHSIZE;
 757
 758         /* It's only used in scanning/building process. */
 759         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 760
 761         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 762                 if (xd->xid==xid)
 763                         return xd;
 764         }
 765         return NULL;
 766 }
 767
 768 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 769 {
 770         struct jffs2_xattr_datum *xd, *_xd;
 771         struct jffs2_xattr_ref *ref, *_ref;
 772         int i;
 773
 774         for (ref=c->xref_temp; ref; ref = _ref) {
 775                 _ref = ref->next;
 776                 jffs2_free_xattr_ref(ref);
 777         }
 778         c->xref_temp = NULL;
 779
 780         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 781                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 782                         list_del(&xd->xindex);
 783                         if (xd->xname)
 784                                 kfree(xd->xname);
 785                         jffs2_free_xattr_datum(xd);
 786                 }
 787         }
 788 }
 789
 790 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 791 {
 792         struct jffs2_xattr_ref *ref, *_ref;
 793         struct jffs2_xattr_datum *xd, *_xd;
 794         struct jffs2_inode_cache *ic;
 795         int i, xdatum_count =0, xdatum_unchecked_count = 0, xref_count = 0;
 796
 797         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 798
 799         /* Phase.1 */
 800         for (ref=c->xref_temp; ref; ref=_ref) {
 801                 _ref = ref->next;
 802                 /* checking REF_UNCHECKED nodes */
 803                 if (ref_flags(ref->node) != REF_PRISTINE) {
 804                         if (verify_xattr_ref(c, ref)) {
 805                                 delete_xattr_ref_node(c, ref);
 806                                 jffs2_free_xattr_ref(ref);
 807                                 continue;
 808                         }
 809                 }
 810                 /* At this point, ref->xid and ref->ino contain XID and inode number.
 811                    ref->xd and ref->ic are not valid yet. */
 812                 xd = jffs2_find_xattr_datum(c, ref->xid);
 813                 ic = jffs2_get_ino_cache(c, ref->ino);
 814                 if (!xd || !ic) {
 815                         if (ref_flags(ref->node) != REF_UNCHECKED)
 816                                 JFFS2_WARNING("xref(ino=%u, xid=%u) is orphan. \n",
 817                                               ref->ino, ref->xid);
 818                         delete_xattr_ref_node(c, ref);
 819                         jffs2_free_xattr_ref(ref);
 820                         continue;
 821                 }
 822                 ref->xd = xd;
 823                 ref->ic = ic;
 824                 xd->refcnt++;
 825                 ref->next = ic->xref;
 826                 ic->xref = ref;
 827                 xref_count++;
 828         }
 829         c->xref_temp = NULL;
 830         /* After this, ref->xid/ino are NEVER used. */
 831
 832         /* Phase.2 */
 833         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 834                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 835                         list_del_init(&xd->xindex);
 836                         if (!xd->refcnt) {
 837                                 if (ref_flags(xd->node) != REF_UNCHECKED)
 838                                         JFFS2_WARNING("orphan xdatum(xid=%u, version=%u) at %#08x\n",
 839                                                       xd->xid, xd->version, ref_offset(xd->node));
 840                                 delete_xattr_datum(c, xd);
 841                                 continue;
 842                         }
 843                         if (ref_flags(xd->node) != REF_PRISTINE) {
 844                                 dbg_xattr("unchecked xdatum(xid=%u) at %#08x\n",
 845                                           xd->xid, ref_offset(xd->node));
 846                                 list_add(&xd->xindex, &c->xattr_unchecked);
 847                                 xdatum_unchecked_count++;
 848                         }
 849                         xdatum_count++;
 850                 }
 851         }
 852         /* build complete */
 853         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum (%u unchecked) and "
 854                      "%u of xref found.\n", xdatum_count, xdatum_unchecked_count, xref_count);
 855 }
 856
 857 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 858                                                   uint32_t xid, uint32_t version)
 859 {
 860         struct jffs2_xattr_datum *xd, *_xd;
 861
 862         _xd = jffs2_find_xattr_datum(c, xid);
 863         if (_xd) {
 864                 dbg_xattr("duplicate xdatum (xid=%u, version=%u/%u) at %#08x\n",
 865                           xid, version, _xd->version, ref_offset(_xd->node));
 866                 if (version < _xd->version)
 867                         return ERR_PTR(-EEXIST);
 868         }
 869         xd = jffs2_alloc_xattr_datum();
 870         if (!xd)
 871                 return ERR_PTR(-ENOMEM);
 872         xd->xid = xid;
 873         xd->version = version;
 874         if (xd->xid > c->highest_xid)
 875                 c->highest_xid = xd->xid;
 876         list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 877
 878         if (_xd) {
 879                 list_del_init(&_xd->xindex);
 880                 delete_xattr_datum_node(c, _xd);
 881                 jffs2_free_xattr_datum(_xd);
 882         }
 883         return xd;
 884 }
 885
 886 /* -------- xattr subsystem functions ---------------
 887  * xprefix_to_handler(xprefix)
 888  *   is used to translate xprefix into xattr_handler.
 889  * jffs2_listxattr(dentry, buffer, size)
 890  *   is an implementation of listxattr handler on jffs2.
 891  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 892  *   is an implementation of getxattr handler on jffs2.
 893  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 894  *   is an implementation of setxattr handler on jffs2.
 895  * -------------------------------------------------- */
 896 struct xattr_handler *jffs2_xattr_handlers[] = {
 897         &jffs2_user_xattr_handler,
 898 #ifdef CONFIG_JFFS2_FS_SECURITY
 899         &jffs2_security_xattr_handler,
 900 #endif
 901 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 902         &jffs2_acl_access_xattr_handler,
 903         &jffs2_acl_default_xattr_handler,
 904 #endif
 905         &jffs2_trusted_xattr_handler,
 906         NULL
 907 };
 908
 909 static struct xattr_handler *xprefix_to_handler(int xprefix) {
 910         struct xattr_handler *ret;
 911
 912         switch (xprefix) {
 913         case JFFS2_XPREFIX_USER:
 914                 ret = &jffs2_user_xattr_handler;
 915                 break;
 916 #ifdef CONFIG_JFFS2_FS_SECURITY
 917         case JFFS2_XPREFIX_SECURITY:
 918                 ret = &jffs2_security_xattr_handler;
 919                 break;
 920 #endif
 921 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 922         case JFFS2_XPREFIX_ACL_ACCESS:
 923                 ret = &jffs2_acl_access_xattr_handler;
 924                 break;
 925         case JFFS2_XPREFIX_ACL_DEFAULT:
 926                 ret = &jffs2_acl_default_xattr_handler;
 927                 break;
 928 #endif
 929         case JFFS2_XPREFIX_TRUSTED:
 930                 ret = &jffs2_trusted_xattr_handler;
 931                 break;
 932         default:
 933                 ret = NULL;
 934                 break;
 935         }
 936         return ret;
 937 }
 938
 939 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 940 {
 941         struct inode *inode = dentry->d_inode;
 942         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 943         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 944         struct jffs2_inode_cache *ic = f->inocache;
 945         struct jffs2_xattr_ref *ref, **pref;
 946         struct jffs2_xattr_datum *xd;
 947         struct xattr_handler *xhandle;
 948         ssize_t len, rc;
 949         int retry = 0;
 950
 951         rc = check_xattr_ref_inode(c, ic);
 952         if (unlikely(rc))
 953                 return rc;
 954
 955         down_read(&c->xattr_sem);
 956  retry:
 957         len = 0;
 958         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 959                 BUG_ON(ref->ic != ic);
 960                 xd = ref->xd;
 961                 if (!xd->xname) {
 962                         /* xdatum is unchached */
 963                         if (!retry) {
 964                                 retry = 1;
 965                                 up_read(&c->xattr_sem);
 966                                 down_write(&c->xattr_sem);
 967                                 goto retry;
 968                         } else {
 969                                 rc = load_xattr_datum(c, xd);
 970                                 if (unlikely(rc > 0)) {
 971                                         *pref = ref->next;
 972                                         delete_xattr_ref(c, ref);
 973                                         goto retry;
 974                                 } else if (unlikely(rc < 0))
 975                                         goto out;
 976                         }
 977                 }
 978                 xhandle = xprefix_to_handler(xd->xprefix);
 979                 if (!xhandle)
 980                         continue;
 981                 if (buffer) {
 982                         rc = xhandle->list(inode, buffer+len, size-len, xd->xname, xd->name_len);
 983                 } else {
 984                         rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
 985                 }
 986                 if (rc < 0)
 987                         goto out;
 988                 len += rc;
 989         }
 990         rc = len;
 991  out:
 992         if (!retry) {
 993                 up_read(&c->xattr_sem);
 994         } else {
 995                 up_write(&c->xattr_sem);
 996         }
 997         return rc;
 998 }
 999
1000 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1001                       char *buffer, size_t size)
1002 {
1003         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1004         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1005         struct jffs2_inode_cache *ic = f->inocache;
1006         struct jffs2_xattr_datum *xd;
1007         struct jffs2_xattr_ref *ref, **pref;
1008         int rc, retry = 0;
1009
1010         rc = check_xattr_ref_inode(c, ic);
1011         if (unlikely(rc))
1012                 return rc;
1013
1014         down_read(&c->xattr_sem);
1015  retry:
1016         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1017                 BUG_ON(ref->ic!=ic);
1018
1019                 xd = ref->xd;
1020                 if (xd->xprefix != xprefix)
1021                         continue;
1022                 if (!xd->xname) {
1023                         /* xdatum is unchached */
1024                         if (!retry) {
1025                                 retry = 1;
1026                                 up_read(&c->xattr_sem);
1027                                 down_write(&c->xattr_sem);
1028                                 goto retry;
1029                         } else {
1030                                 rc = load_xattr_datum(c, xd);
1031                                 if (unlikely(rc > 0)) {
1032                                         *pref = ref->next;
1033                                         delete_xattr_ref(c, ref);
1034                                         goto retry;
1035                                 } else if (unlikely(rc < 0)) {
1036                                         goto out;
1037                                 }
1038                         }
1039                 }
1040                 if (!strcmp(xname, xd->xname)) {
1041                         rc = xd->value_len;
1042                         if (buffer) {
1043                                 if (size < rc) {
1044                                         rc = -ERANGE;
1045                                 } else {
1046                                         memcpy(buffer, xd->xvalue, rc);
1047                                 }
1048                         }
1049                         goto out;
1050                 }
1051         }
1052         rc = -ENODATA;
1053  out:
1054         if (!retry) {
1055                 up_read(&c->xattr_sem);
1056         } else {
1057                 up_write(&c->xattr_sem);
1058         }
1059         return rc;
1060 }
1061
1062 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1063                       const char *buffer, size_t size, int flags)
1064 {
1065         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1066         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1067         struct jffs2_inode_cache *ic = f->inocache;
1068         struct jffs2_xattr_datum *xd;
1069         struct jffs2_xattr_ref *ref, *newref, **pref;
1070         uint32_t phys_ofs, length, request;
1071         int rc;
1072
1073         rc = check_xattr_ref_inode(c, ic);
1074         if (unlikely(rc))
1075                 return rc;
1076
1077         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1078         rc = jffs2_reserve_space(c, request, &phys_ofs, &length,
1079                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1080         if (rc) {
1081                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1082                 return rc;
1083         }
1084
1085         /* Find existing xattr */
1086         down_write(&c->xattr_sem);
1087  retry:
1088         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1089                 xd = ref->xd;
1090                 if (xd->xprefix != xprefix)
1091                         continue;
1092                 if (!xd->xname) {
1093                         rc = load_xattr_datum(c, xd);
1094                         if (unlikely(rc > 0)) {
1095                                 *pref = ref->next;
1096                                 delete_xattr_ref(c, ref);
1097                                 goto retry;
1098                         } else if (unlikely(rc < 0))
1099                                 goto out;
1100                 }
1101                 if (!strcmp(xd->xname, xname)) {
1102                         if (flags & XATTR_CREATE) {
1103                                 rc = -EEXIST;
1104                                 goto out;
1105                         }
1106                         if (!buffer) {
1107                                 *pref = ref->next;
1108                                 delete_xattr_ref(c, ref);
1109                                 rc = 0;
1110                                 goto out;
1111                         }
1112                         goto found;
1113                 }
1114         }
1115         /* not found */
1116         if (flags & XATTR_REPLACE) {
1117                 rc = -ENODATA;
1118                 goto out;
1119         }
1120         if (!buffer) {
1121                 rc = -EINVAL;
1122                 goto out;
1123         }
1124  found:
1125         xd = create_xattr_datum(c, xprefix, xname, buffer, size, phys_ofs);
1126         if (IS_ERR(xd)) {
1127                 rc = PTR_ERR(xd);
1128                 goto out;
1129         }
1130         up_write(&c->xattr_sem);
1131         jffs2_complete_reservation(c);
1132
1133         /* create xattr_ref */
1134         request = PAD(sizeof(struct jffs2_raw_xref));
1135         rc = jffs2_reserve_space(c, request, &phys_ofs, &length,
1136                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1137         if (rc) {
1138                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1139                 down_write(&c->xattr_sem);
1140                 xd->refcnt--;
1141                 if (!xd->refcnt)
1142                         delete_xattr_datum(c, xd);
1143                 up_write(&c->xattr_sem);
1144                 return rc;
1145         }
1146         down_write(&c->xattr_sem);
1147         if (ref)
1148                 *pref = ref->next;
1149         newref = create_xattr_ref(c, ic, xd, phys_ofs);
1150         if (IS_ERR(newref)) {
1151                 if (ref) {
1152                         ref->next = ic->xref;
1153                         ic->xref = ref;
1154                 }
1155                 rc = PTR_ERR(newref);
1156                 xd->refcnt--;
1157                 if (!xd->refcnt)
1158                         delete_xattr_datum(c, xd);
1159         } else if (ref) {
1160                 delete_xattr_ref(c, ref);
1161         }
1162  out:
1163         up_write(&c->xattr_sem);
1164         jffs2_complete_reservation(c);
1165         return rc;
1166 }
1167
1168 /* -------- garbage collector functions -------------
1169  * jffs2_garbage_collect_xattr_datum(c, xd)
1170  *   is used to move xdatum into new node.
1171  * jffs2_garbage_collect_xattr_ref(c, ref)
1172  *   is used to move xref into new node.
1173  * jffs2_verify_xattr(c)
1174  *   is used to call do_verify_xattr_datum() before garbage collecting.
1175  * -------------------------------------------------- */
1176 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1177 {
1178         uint32_t phys_ofs, totlen, length, old_ofs;
1179         int rc = -EINVAL;
1180
1181         down_write(&c->xattr_sem);
1182         BUG_ON(!xd->node);
1183
1184         old_ofs = ref_offset(xd->node);
1185         totlen = ref_totlen(c, c->gcblock, xd->node);
1186         if (totlen < sizeof(struct jffs2_raw_xattr))
1187                 goto out;
1188
1189         if (!xd->xname) {
1190                 rc = load_xattr_datum(c, xd);
1191                 if (unlikely(rc > 0)) {
1192                         delete_xattr_datum_node(c, xd);
1193                         rc = 0;
1194                         goto out;
1195                 } else if (unlikely(rc < 0))
1196                         goto out;
1197         }
1198         rc = jffs2_reserve_space_gc(c, totlen, &phys_ofs, &length, JFFS2_SUMMARY_XATTR_SIZE);
1199         if (rc || length < totlen) {
1200                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, totlen);
1201                 rc = rc ? rc : -EBADFD;
1202                 goto out;
1203         }
1204         rc = save_xattr_datum(c, xd, phys_ofs);
1205         if (!rc)
1206                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1207                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1208  out:
1209         up_write(&c->xattr_sem);
1210         return rc;
1211 }
1212
1213
1214 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1215 {
1216         uint32_t phys_ofs, totlen, length, old_ofs;
1217         int rc = -EINVAL;
1218
1219         down_write(&c->xattr_sem);
1220         BUG_ON(!ref->node);
1221
1222         old_ofs = ref_offset(ref->node);
1223         totlen = ref_totlen(c, c->gcblock, ref->node);
1224         if (totlen != sizeof(struct jffs2_raw_xref))
1225                 goto out;
1226
1227         rc = jffs2_reserve_space_gc(c, totlen, &phys_ofs, &length, JFFS2_SUMMARY_XREF_SIZE);
1228         if (rc || length < totlen) {
1229                 JFFS2_WARNING("%s: jffs2_reserve_space() = %d, request = %u\n",
1230                               __FUNCTION__, rc, totlen);
1231                 rc = rc ? rc : -EBADFD;
1232                 goto out;
1233         }
1234         rc = save_xattr_ref(c, ref, phys_ofs);
1235         if (!rc)
1236                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1237                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1238  out:
1239         up_write(&c->xattr_sem);
1240         return rc;
1241 }
1242
1243 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1244 {
1245         struct jffs2_xattr_datum *xd, *_xd;
1246         int rc;
1247
1248         down_write(&c->xattr_sem);
1249         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1250                 rc = do_verify_xattr_datum(c, xd);
1251                 if (rc == 0) {
1252                         list_del_init(&xd->xindex);
1253                         break;
1254                 } else if (rc > 0) {
1255                         list_del_init(&xd->xindex);
1256                         delete_xattr_datum_node(c, xd);
1257                 }
1258         }
1259         up_write(&c->xattr_sem);
1260
1261         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1262 }