fs/jffs2/xattr.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 2006  NEC Corporation
   5  *
   6  * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/fs.h>
  14 #include <linux/time.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/highmem.h>
  17 #include <linux/crc32.h>
  18 #include <linux/jffs2.h>
  19 #include <linux/xattr.h>
  20 #include <linux/mtd/mtd.h>
  21 #include "nodelist.h"
  22 /* -------- xdatum related functions ----------------
  23  * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  24  *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  25  *   the index of the xattr name/value pair cache (c->xattrindex).
  26  * is_xattr_datum_unchecked(c, xd)
  27  *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  28  *   unchecked, it returns 0.
  29  * unload_xattr_datum(c, xd)
  30  *   is used to release xattr name/value pair and detach from c->xattrindex.
  31  * reclaim_xattr_datum(c)
  32  *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  33  *   memory usage by cache is over c->xdatum_mem_threshold. Currentry, this threshold
  34  *   is hard coded as 32KiB.
  35  * do_verify_xattr_datum(c, xd)
  36  *   is used to load the xdatum informations without name/value pair from the medium.
  37  *   It's necessary once, because those informations are not collected during mounting
  38  *   process when EBS is enabled.
  39  *   0 will be returned, if success. An negative return value means recoverable error, and
  40  *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  41  *   and xref when it returned positive value.
  42  * do_load_xattr_datum(c, xd)
  43  *   is used to load name/value pair from the medium.
  44  *   The meanings of return value is same as do_verify_xattr_datum().
  45  * load_xattr_datum(c, xd)
  46  *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  47  *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  48  *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  49  * save_xattr_datum(c, xd)
  50  *   is used to write xdatum to medium. xd->version will be incremented.
  51  * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  52  *   is used to create new xdatum and write to medium.
  53  * unrefer_xattr_datum(c, xd)
  54  *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
  55  *   is set on xd->flags and chained xattr_dead_list or release it immediately.
  56  *   In the first case, the garbage collector release it later.
  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 int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  66 {
  67         struct jffs2_raw_node_ref *raw;
  68         int rc = 0;
  69
  70         spin_lock(&c->erase_completion_lock);
  71         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
  72                 if (ref_flags(raw) == REF_UNCHECKED) {
  73                         rc = 1;
  74                         break;
  75                 }
  76         }
  77         spin_unlock(&c->erase_completion_lock);
  78         return rc;
  79 }
  80
  81 static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  82 {
  83         /* must be called under down_write(xattr_sem) */
  84         D1(dbg_xattr("%s: xid=%u, version=%u\n", __FUNCTION__, xd->xid, xd->version));
  85         if (xd->xname) {
  86                 c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  87                 kfree(xd->xname);
  88         }
  89
  90         list_del_init(&xd->xindex);
  91         xd->hashkey = 0;
  92         xd->xname = NULL;
  93         xd->xvalue = NULL;
  94 }
  95
  96 static void reclaim_xattr_datum(struct jffs2_sb_info *c)
  97 {
  98         /* must be called under down_write(xattr_sem) */
  99         struct jffs2_xattr_datum *xd, *_xd;
 100         uint32_t target, before;
 101         static int index = 0;
 102         int count;
 103
 104         if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
 105                 return;
 106
 107         before = c->xdatum_mem_usage;
 108         target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
 109         for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
 110                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
 111                         if (xd->flags & JFFS2_XFLAGS_HOT) {
 112                                 xd->flags &= ~JFFS2_XFLAGS_HOT;
 113                         } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
 114                                 unload_xattr_datum(c, xd);
 115                         }
 116                         if (c->xdatum_mem_usage <= target)
 117                                 goto out;
 118                 }
 119                 index = (index+1) % XATTRINDEX_HASHSIZE;
 120         }
 121  out:
 122         JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 123                      before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 124 }
 125
 126 static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 127 {
 128         /* must be called under down_write(xattr_sem) */
 129         struct jffs2_eraseblock *jeb;
 130         struct jffs2_raw_node_ref *raw;
 131         struct jffs2_raw_xattr rx;
 132         size_t readlen;
 133         uint32_t crc, offset, totlen;
 134         int rc;
 135
 136         spin_lock(&c->erase_completion_lock);
 137         offset = ref_offset(xd->node);
 138         if (ref_flags(xd->node) == REF_PRISTINE)
 139                 goto complete;
 140         spin_unlock(&c->erase_completion_lock);
 141
 142         rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
 143         if (rc || readlen != sizeof(rx)) {
 144                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
 145                               rc, sizeof(rx), readlen, offset);
 146                 return rc ? rc : -EIO;
 147         }
 148         crc = crc32(0, &rx, sizeof(rx) - 4);
 149         if (crc != je32_to_cpu(rx.node_crc)) {
 150                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 151                             offset, je32_to_cpu(rx.hdr_crc), crc);
 152                 xd->flags |= JFFS2_XFLAGS_INVALID;
 153                 return EIO;
 154         }
 155         totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 156         if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 157             || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 158             || je32_to_cpu(rx.totlen) != totlen
 159             || je32_to_cpu(rx.xid) != xd->xid
 160             || je32_to_cpu(rx.version) != xd->version) {
 161                 JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 162                             "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 163                             offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
 164                             je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
 165                             je32_to_cpu(rx.totlen), totlen,
 166                             je32_to_cpu(rx.xid), xd->xid,
 167                             je32_to_cpu(rx.version), xd->version);
 168                 xd->flags |= JFFS2_XFLAGS_INVALID;
 169                 return EIO;
 170         }
 171         xd->xprefix = rx.xprefix;
 172         xd->name_len = rx.name_len;
 173         xd->value_len = je16_to_cpu(rx.value_len);
 174         xd->data_crc = je32_to_cpu(rx.data_crc);
 175
 176         spin_lock(&c->erase_completion_lock);
 177  complete:
 178         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
 179                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 180                 totlen = PAD(ref_totlen(c, jeb, raw));
 181                 if (ref_flags(raw) == REF_UNCHECKED) {
 182                         c->unchecked_size -= totlen; c->used_size += totlen;
 183                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 184                 }
 185                 raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
 186         }
 187         spin_unlock(&c->erase_completion_lock);
 188
 189         /* unchecked xdatum is chained with c->xattr_unchecked */
 190         list_del_init(&xd->xindex);
 191
 192         dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
 193                   xd->xid, xd->version);
 194
 195         return 0;
 196 }
 197
 198 static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 199 {
 200         /* must be called under down_write(xattr_sem) */
 201         char *data;
 202         size_t readlen;
 203         uint32_t crc, length;
 204         int i, ret, retry = 0;
 205
 206         BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 207         BUG_ON(!list_empty(&xd->xindex));
 208  retry:
 209         length = xd->name_len + 1 + xd->value_len;
 210         data = kmalloc(length, GFP_KERNEL);
 211         if (!data)
 212                 return -ENOMEM;
 213
 214         ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 215                                length, &readlen, data);
 216
 217         if (ret || length!=readlen) {
 218                 JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
 219                               ret, length, readlen, ref_offset(xd->node));
 220                 kfree(data);
 221                 return ret ? ret : -EIO;
 222         }
 223
 224         data[xd->name_len] = '\0';
 225         crc = crc32(0, data, length);
 226         if (crc != xd->data_crc) {
 227                 JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XREF)"
 228                               " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 229                               ref_offset(xd->node), xd->data_crc, crc);
 230                 kfree(data);
 231                 xd->flags |= JFFS2_XFLAGS_INVALID;
 232                 return EIO;
 233         }
 234
 235         xd->flags |= JFFS2_XFLAGS_HOT;
 236         xd->xname = data;
 237         xd->xvalue = data + xd->name_len+1;
 238
 239         c->xdatum_mem_usage += length;
 240
 241         xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 242         i = xd->hashkey % XATTRINDEX_HASHSIZE;
 243         list_add(&xd->xindex, &c->xattrindex[i]);
 244         if (!retry) {
 245                 retry = 1;
 246                 reclaim_xattr_datum(c);
 247                 if (!xd->xname)
 248                         goto retry;
 249         }
 250
 251         dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 252                   xd->xid, xd->xprefix, xd->xname);
 253
 254         return 0;
 255 }
 256
 257 static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 258 {
 259         /* must be called under down_write(xattr_sem);
 260          * rc < 0 : recoverable error, try again
 261          * rc = 0 : success
 262          * rc > 0 : Unrecoverable error, this node should be deleted.
 263          */
 264         int rc = 0;
 265
 266         BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
 267         if (xd->xname)
 268                 return 0;
 269         if (xd->flags & JFFS2_XFLAGS_INVALID)
 270                 return EIO;
 271         if (unlikely(is_xattr_datum_unchecked(c, xd)))
 272                 rc = do_verify_xattr_datum(c, xd);
 273         if (!rc)
 274                 rc = do_load_xattr_datum(c, xd);
 275         return rc;
 276 }
 277
 278 static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 279 {
 280         /* must be called under down_write(xattr_sem) */
 281         struct jffs2_raw_xattr rx;
 282         struct kvec vecs[2];
 283         size_t length;
 284         int rc, totlen;
 285         uint32_t phys_ofs = write_ofs(c);
 286
 287         BUG_ON(!xd->xname);
 288         BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
 289
 290         vecs[0].iov_base = &rx;
 291         vecs[0].iov_len = sizeof(rx);
 292         vecs[1].iov_base = xd->xname;
 293         vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 294         totlen = vecs[0].iov_len + vecs[1].iov_len;
 295
 296         /* Setup raw-xattr */
 297         memset(&rx, 0, sizeof(rx));
 298         rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 299         rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 300         rx.totlen = cpu_to_je32(PAD(totlen));
 301         rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 302
 303         rx.xid = cpu_to_je32(xd->xid);
 304         rx.version = cpu_to_je32(++xd->version);
 305         rx.xprefix = xd->xprefix;
 306         rx.name_len = xd->name_len;
 307         rx.value_len = cpu_to_je16(xd->value_len);
 308         rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 309         rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 310
 311         rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 312         if (rc || totlen != length) {
 313                 JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
 314                               rc, totlen, length, phys_ofs);
 315                 rc = rc ? rc : -EIO;
 316                 if (length)
 317                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
 318
 319                 return rc;
 320         }
 321         /* success */
 322         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
 323
 324         dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 325                   xd->xid, xd->version, xd->xprefix, xd->xname);
 326
 327         return 0;
 328 }
 329
 330 static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 331                                                     int xprefix, const char *xname,
 332                                                     const char *xvalue, int xsize)
 333 {
 334         /* must be called under down_write(xattr_sem) */
 335         struct jffs2_xattr_datum *xd;
 336         uint32_t hashkey, name_len;
 337         char *data;
 338         int i, rc;
 339
 340         /* Search xattr_datum has same xname/xvalue by index */
 341         hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 342         i = hashkey % XATTRINDEX_HASHSIZE;
 343         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 344                 if (xd->hashkey==hashkey
 345                     && xd->xprefix==xprefix
 346                     && xd->value_len==xsize
 347                     && !strcmp(xd->xname, xname)
 348                     && !memcmp(xd->xvalue, xvalue, xsize)) {
 349                         atomic_inc(&xd->refcnt);
 350                         return xd;
 351                 }
 352         }
 353
 354         /* Not found, Create NEW XATTR-Cache */
 355         name_len = strlen(xname);
 356
 357         xd = jffs2_alloc_xattr_datum();
 358         if (!xd)
 359                 return ERR_PTR(-ENOMEM);
 360
 361         data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 362         if (!data) {
 363                 jffs2_free_xattr_datum(xd);
 364                 return ERR_PTR(-ENOMEM);
 365         }
 366         strcpy(data, xname);
 367         memcpy(data + name_len + 1, xvalue, xsize);
 368
 369         atomic_set(&xd->refcnt, 1);
 370         xd->xid = ++c->highest_xid;
 371         xd->flags |= JFFS2_XFLAGS_HOT;
 372         xd->xprefix = xprefix;
 373
 374         xd->hashkey = hashkey;
 375         xd->xname = data;
 376         xd->xvalue = data + name_len + 1;
 377         xd->name_len = name_len;
 378         xd->value_len = xsize;
 379         xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 380
 381         rc = save_xattr_datum(c, xd);
 382         if (rc) {
 383                 kfree(xd->xname);
 384                 jffs2_free_xattr_datum(xd);
 385                 return ERR_PTR(rc);
 386         }
 387
 388         /* Insert Hash Index */
 389         i = hashkey % XATTRINDEX_HASHSIZE;
 390         list_add(&xd->xindex, &c->xattrindex[i]);
 391
 392         c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 393         reclaim_xattr_datum(c);
 394
 395         return xd;
 396 }
 397
 398 static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 399 {
 400         /* must be called under down_write(xattr_sem) */
 401         if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
 402                 unload_xattr_datum(c, xd);
 403                 xd->flags |= JFFS2_XFLAGS_DEAD;
 404                 if (xd->node == (void *)xd) {
 405                         BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 406                         jffs2_free_xattr_datum(xd);
 407                 } else {
 408                         list_add(&xd->xindex, &c->xattr_dead_list);
 409                 }
 410                 spin_unlock(&c->erase_completion_lock);
 411
 412                 dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
 413                           xd->xid, xd->version);
 414         }
 415 }
 416
 417 /* -------- xref related functions ------------------
 418  * verify_xattr_ref(c, ref)
 419  *   is used to load xref information from medium. Because summary data does not
 420  *   contain xid/ino, it's necessary to verify once while mounting process.
 421  * save_xattr_ref(c, ref)
 422  *   is used to write xref to medium. If delete marker is marked, it write
 423  *   a delete marker of xref into medium.
 424  * create_xattr_ref(c, ic, xd)
 425  *   is used to create a new xref and write to medium.
 426  * delete_xattr_ref(c, ref)
 427  *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 428  *   and allows GC to reclaim those physical nodes.
 429  * jffs2_xattr_delete_inode(c, ic)
 430  *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 431  * jffs2_xattr_free_inode(c, ic)
 432  *   is called to release xattr related objects when unmounting.
 433  * check_xattr_ref_inode(c, ic)
 434  *   is used to confirm inode does not have duplicate xattr name/value pair.
 435  * -------------------------------------------------- */
 436 static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 437 {
 438         struct jffs2_eraseblock *jeb;
 439         struct jffs2_raw_node_ref *raw;
 440         struct jffs2_raw_xref rr;
 441         size_t readlen;
 442         uint32_t crc, offset, totlen;
 443         int rc;
 444
 445         spin_lock(&c->erase_completion_lock);
 446         if (ref_flags(ref->node) != REF_UNCHECKED)
 447                 goto complete;
 448         offset = ref_offset(ref->node);
 449         spin_unlock(&c->erase_completion_lock);
 450
 451         rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
 452         if (rc || sizeof(rr) != readlen) {
 453                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
 454                               rc, sizeof(rr), readlen, offset);
 455                 return rc ? rc : -EIO;
 456         }
 457         /* obsolete node */
 458         crc = crc32(0, &rr, sizeof(rr) - 4);
 459         if (crc != je32_to_cpu(rr.node_crc)) {
 460                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 461                             offset, je32_to_cpu(rr.node_crc), crc);
 462                 return EIO;
 463         }
 464         if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 465             || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 466             || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 467                 JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 468                             "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
 469                             offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 470                             je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 471                             je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 472                 return EIO;
 473         }
 474         ref->ino = je32_to_cpu(rr.ino);
 475         ref->xid = je32_to_cpu(rr.xid);
 476         ref->xseqno = je32_to_cpu(rr.xseqno);
 477         if (ref->xseqno > c->highest_xseqno)
 478                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 479
 480         spin_lock(&c->erase_completion_lock);
 481  complete:
 482         for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
 483                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 484                 totlen = PAD(ref_totlen(c, jeb, raw));
 485                 if (ref_flags(raw) == REF_UNCHECKED) {
 486                         c->unchecked_size -= totlen; c->used_size += totlen;
 487                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 488                 }
 489                 raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
 490         }
 491         spin_unlock(&c->erase_completion_lock);
 492
 493         dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 494                   ref->ino, ref->xid, ref_offset(ref->node));
 495         return 0;
 496 }
 497
 498 static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 499 {
 500         /* must be called under down_write(xattr_sem) */
 501         struct jffs2_raw_xref rr;
 502         size_t length;
 503         uint32_t xseqno, phys_ofs = write_ofs(c);
 504         int ret;
 505
 506         rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 507         rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 508         rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 509         rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 510
 511         xseqno = (c->highest_xseqno += 2);
 512         if (is_xattr_ref_dead(ref)) {
 513                 xseqno |= XREF_DELETE_MARKER;
 514                 rr.ino = cpu_to_je32(ref->ino);
 515                 rr.xid = cpu_to_je32(ref->xid);
 516         } else {
 517                 rr.ino = cpu_to_je32(ref->ic->ino);
 518                 rr.xid = cpu_to_je32(ref->xd->xid);
 519         }
 520         rr.xseqno = cpu_to_je32(xseqno);
 521         rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 522
 523         ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 524         if (ret || sizeof(rr) != length) {
 525                 JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
 526                               ret, sizeof(rr), length, phys_ofs);
 527                 ret = ret ? ret : -EIO;
 528                 if (length)
 529                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
 530
 531                 return ret;
 532         }
 533         /* success */
 534         ref->xseqno = xseqno;
 535         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
 536
 537         dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 538
 539         return 0;
 540 }
 541
 542 static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 543                                                 struct jffs2_xattr_datum *xd)
 544 {
 545         /* must be called under down_write(xattr_sem) */
 546         struct jffs2_xattr_ref *ref;
 547         int ret;
 548
 549         ref = jffs2_alloc_xattr_ref();
 550         if (!ref)
 551                 return ERR_PTR(-ENOMEM);
 552         ref->ic = ic;
 553         ref->xd = xd;
 554
 555         ret = save_xattr_ref(c, ref);
 556         if (ret) {
 557                 jffs2_free_xattr_ref(ref);
 558                 return ERR_PTR(ret);
 559         }
 560
 561         /* Chain to inode */
 562         ref->next = ic->xref;
 563         ic->xref = ref;
 564
 565         return ref; /* success */
 566 }
 567
 568 static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 569 {
 570         /* must be called under down_write(xattr_sem) */
 571         struct jffs2_xattr_datum *xd;
 572
 573         xd = ref->xd;
 574         ref->xseqno |= XREF_DELETE_MARKER;
 575         ref->ino = ref->ic->ino;
 576         ref->xid = ref->xd->xid;
 577         spin_lock(&c->erase_completion_lock);
 578         ref->next = c->xref_dead_list;
 579         c->xref_dead_list = ref;
 580         spin_unlock(&c->erase_completion_lock);
 581
 582         dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
 583                   ref->ino, ref->xid, ref->xseqno);
 584
 585         unrefer_xattr_datum(c, xd);
 586 }
 587
 588 void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 589 {
 590         /* It's called from jffs2_clear_inode() on inode removing.
 591            When an inode with XATTR is removed, those XATTRs must be removed. */
 592         struct jffs2_xattr_ref *ref, *_ref;
 593
 594         if (!ic || ic->nlink > 0)
 595                 return;
 596
 597         down_write(&c->xattr_sem);
 598         for (ref = ic->xref; ref; ref = _ref) {
 599                 _ref = ref->next;
 600                 delete_xattr_ref(c, ref);
 601         }
 602         ic->xref = NULL;
 603         up_write(&c->xattr_sem);
 604 }
 605
 606 void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 607 {
 608         /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 609         struct jffs2_xattr_datum *xd;
 610         struct jffs2_xattr_ref *ref, *_ref;
 611
 612         down_write(&c->xattr_sem);
 613         for (ref = ic->xref; ref; ref = _ref) {
 614                 _ref = ref->next;
 615                 xd = ref->xd;
 616                 if (atomic_dec_and_test(&xd->refcnt)) {
 617                         unload_xattr_datum(c, xd);
 618                         jffs2_free_xattr_datum(xd);
 619                 }
 620                 jffs2_free_xattr_ref(ref);
 621         }
 622         ic->xref = NULL;
 623         up_write(&c->xattr_sem);
 624 }
 625
 626 static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 627 {
 628         /* success of check_xattr_ref_inode() means taht inode (ic) dose not have
 629          * duplicate name/value pairs. If duplicate name/value pair would be found,
 630          * one will be removed.
 631          */
 632         struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 633         int rc = 0;
 634
 635         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 636                 return 0;
 637         down_write(&c->xattr_sem);
 638  retry:
 639         rc = 0;
 640         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 641                 if (!ref->xd->xname) {
 642                         rc = load_xattr_datum(c, ref->xd);
 643                         if (unlikely(rc > 0)) {
 644                                 *pref = ref->next;
 645                                 delete_xattr_ref(c, ref);
 646                                 goto retry;
 647                         } else if (unlikely(rc < 0))
 648                                 goto out;
 649                 }
 650                 for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 651                         if (!cmp->xd->xname) {
 652                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
 653                                 rc = load_xattr_datum(c, cmp->xd);
 654                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 655                                 if (unlikely(rc > 0)) {
 656                                         *pcmp = cmp->next;
 657                                         delete_xattr_ref(c, cmp);
 658                                         goto retry;
 659                                 } else if (unlikely(rc < 0))
 660                                         goto out;
 661                         }
 662                         if (ref->xd->xprefix == cmp->xd->xprefix
 663                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 664                                 if (ref->xseqno > cmp->xseqno) {
 665                                         *pcmp = cmp->next;
 666                                         delete_xattr_ref(c, cmp);
 667                                 } else {
 668                                         *pref = ref->next;
 669                                         delete_xattr_ref(c, ref);
 670                                 }
 671                                 goto retry;
 672                         }
 673                 }
 674         }
 675         ic->flags |= INO_FLAGS_XATTR_CHECKED;
 676  out:
 677         up_write(&c->xattr_sem);
 678
 679         return rc;
 680 }
 681
 682 /* -------- xattr subsystem functions ---------------
 683  * jffs2_init_xattr_subsystem(c)
 684  *   is used to initialize semaphore and list_head, and some variables.
 685  * jffs2_find_xattr_datum(c, xid)
 686  *   is used to lookup xdatum while scanning process.
 687  * jffs2_clear_xattr_subsystem(c)
 688  *   is used to release any xattr related objects.
 689  * jffs2_build_xattr_subsystem(c)
 690  *   is used to associate xdatum and xref while super block building process.
 691  * jffs2_setup_xattr_datum(c, xid, version)
 692  *   is used to insert xdatum while scanning process.
 693  * -------------------------------------------------- */
 694 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 695 {
 696         int i;
 697
 698         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 699                 INIT_LIST_HEAD(&c->xattrindex[i]);
 700         INIT_LIST_HEAD(&c->xattr_unchecked);
 701         INIT_LIST_HEAD(&c->xattr_dead_list);
 702         c->xref_dead_list = NULL;
 703         c->xref_temp = NULL;
 704
 705         init_rwsem(&c->xattr_sem);
 706         c->highest_xid = 0;
 707         c->highest_xseqno = 0;
 708         c->xdatum_mem_usage = 0;
 709         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 710 }
 711
 712 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 713 {
 714         struct jffs2_xattr_datum *xd;
 715         int i = xid % XATTRINDEX_HASHSIZE;
 716
 717         /* It's only used in scanning/building process. */
 718         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 719
 720         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 721                 if (xd->xid==xid)
 722                         return xd;
 723         }
 724         return NULL;
 725 }
 726
 727 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 728 {
 729         struct jffs2_xattr_datum *xd, *_xd;
 730         struct jffs2_xattr_ref *ref, *_ref;
 731         int i;
 732
 733         for (ref=c->xref_temp; ref; ref = _ref) {
 734                 _ref = ref->next;
 735                 jffs2_free_xattr_ref(ref);
 736         }
 737
 738         for (ref=c->xref_dead_list; ref; ref = _ref) {
 739                 _ref = ref->next;
 740                 jffs2_free_xattr_ref(ref);
 741         }
 742
 743         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 744                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 745                         list_del(&xd->xindex);
 746                         if (xd->xname)
 747                                 kfree(xd->xname);
 748                         jffs2_free_xattr_datum(xd);
 749                 }
 750         }
 751
 752         list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
 753                 list_del(&xd->xindex);
 754                 jffs2_free_xattr_datum(xd);
 755         }
 756 }
 757
 758 #define XREF_TMPHASH_SIZE       (128)
 759 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 760 {
 761         struct jffs2_xattr_ref *ref, *_ref;
 762         struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
 763         struct jffs2_xattr_datum *xd, *_xd;
 764         struct jffs2_inode_cache *ic;
 765         struct jffs2_raw_node_ref *raw;
 766         int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
 767         int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
 768
 769         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 770
 771         /* Phase.1 : Merge same xref */
 772         for (i=0; i < XREF_TMPHASH_SIZE; i++)
 773                 xref_tmphash[i] = NULL;
 774         for (ref=c->xref_temp; ref; ref=_ref) {
 775                 struct jffs2_xattr_ref *tmp;
 776
 777                 _ref = ref->next;
 778                 if (ref_flags(ref->node) != REF_PRISTINE) {
 779                         if (verify_xattr_ref(c, ref)) {
 780                                 BUG_ON(ref->node->next_in_ino != (void *)ref);
 781                                 ref->node->next_in_ino = NULL;
 782                                 jffs2_mark_node_obsolete(c, ref->node);
 783                                 jffs2_free_xattr_ref(ref);
 784                                 continue;
 785                         }
 786                 }
 787
 788                 i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
 789                 for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
 790                         if (tmp->ino == ref->ino && tmp->xid == ref->xid)
 791                                 break;
 792                 }
 793                 if (tmp) {
 794                         raw = ref->node;
 795                         if (ref->xseqno > tmp->xseqno) {
 796                                 tmp->xseqno = ref->xseqno;
 797                                 raw->next_in_ino = tmp->node;
 798                                 tmp->node = raw;
 799                         } else {
 800                                 raw->next_in_ino = tmp->node->next_in_ino;
 801                                 tmp->node->next_in_ino = raw;
 802                         }
 803                         jffs2_free_xattr_ref(ref);
 804                         continue;
 805                 } else {
 806                         ref->next = xref_tmphash[i];
 807                         xref_tmphash[i] = ref;
 808                 }
 809         }
 810         c->xref_temp = NULL;
 811
 812         /* Phase.2 : Bind xref with inode_cache and xattr_datum */
 813         for (i=0; i < XREF_TMPHASH_SIZE; i++) {
 814                 for (ref=xref_tmphash[i]; ref; ref=_ref) {
 815                         xref_count++;
 816                         _ref = ref->next;
 817                         if (is_xattr_ref_dead(ref)) {
 818                                 ref->next = c->xref_dead_list;
 819                                 c->xref_dead_list = ref;
 820                                 xref_dead_count++;
 821                                 continue;
 822                         }
 823                         /* At this point, ref->xid and ref->ino contain XID and inode number.
 824                            ref->xd and ref->ic are not valid yet. */
 825                         xd = jffs2_find_xattr_datum(c, ref->xid);
 826                         ic = jffs2_get_ino_cache(c, ref->ino);
 827                         if (!xd || !ic) {
 828                                 dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
 829                                           ref->ino, ref->xid, ref->xseqno);
 830                                 ref->xseqno |= XREF_DELETE_MARKER;
 831                                 ref->next = c->xref_dead_list;
 832                                 c->xref_dead_list = ref;
 833                                 xref_orphan_count++;
 834                                 continue;
 835                         }
 836                         ref->xd = xd;
 837                         ref->ic = ic;
 838                         atomic_inc(&xd->refcnt);
 839                         ref->next = ic->xref;
 840                         ic->xref = ref;
 841                 }
 842         }
 843
 844         /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
 845         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 846                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 847                         xdatum_count++;
 848                         list_del_init(&xd->xindex);
 849                         if (!atomic_read(&xd->refcnt)) {
 850                                 dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
 851                                           xd->xid, xd->version);
 852                                 xd->flags |= JFFS2_XFLAGS_DEAD;
 853                                 list_add(&xd->xindex, &c->xattr_unchecked);
 854                                 xdatum_orphan_count++;
 855                                 continue;
 856                         }
 857                         if (is_xattr_datum_unchecked(c, xd)) {
 858                                 dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
 859                                           xd->xid, xd->version);
 860                                 list_add(&xd->xindex, &c->xattr_unchecked);
 861                                 xdatum_unchecked_count++;
 862                         }
 863                 }
 864         }
 865         /* build complete */
 866         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
 867                      " (%u unchecked, %u orphan) and "
 868                      "%u of xref (%u dead, %u orphan) found.\n",
 869                      xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
 870                      xref_count, xref_dead_count, xref_orphan_count);
 871 }
 872
 873 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 874                                                   uint32_t xid, uint32_t version)
 875 {
 876         struct jffs2_xattr_datum *xd;
 877
 878         xd = jffs2_find_xattr_datum(c, xid);
 879         if (!xd) {
 880                 xd = jffs2_alloc_xattr_datum();
 881                 if (!xd)
 882                         return ERR_PTR(-ENOMEM);
 883                 xd->xid = xid;
 884                 xd->version = version;
 885                 if (xd->xid > c->highest_xid)
 886                         c->highest_xid = xd->xid;
 887                 list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 888         }
 889         return xd;
 890 }
 891
 892 /* -------- xattr subsystem functions ---------------
 893  * xprefix_to_handler(xprefix)
 894  *   is used to translate xprefix into xattr_handler.
 895  * jffs2_listxattr(dentry, buffer, size)
 896  *   is an implementation of listxattr handler on jffs2.
 897  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 898  *   is an implementation of getxattr handler on jffs2.
 899  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 900  *   is an implementation of setxattr handler on jffs2.
 901  * -------------------------------------------------- */
 902 struct xattr_handler *jffs2_xattr_handlers[] = {
 903         &jffs2_user_xattr_handler,
 904 #ifdef CONFIG_JFFS2_FS_SECURITY
 905         &jffs2_security_xattr_handler,
 906 #endif
 907 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 908         &jffs2_acl_access_xattr_handler,
 909         &jffs2_acl_default_xattr_handler,
 910 #endif
 911         &jffs2_trusted_xattr_handler,
 912         NULL
 913 };
 914
 915 static struct xattr_handler *xprefix_to_handler(int xprefix) {
 916         struct xattr_handler *ret;
 917
 918         switch (xprefix) {
 919         case JFFS2_XPREFIX_USER:
 920                 ret = &jffs2_user_xattr_handler;
 921                 break;
 922 #ifdef CONFIG_JFFS2_FS_SECURITY
 923         case JFFS2_XPREFIX_SECURITY:
 924                 ret = &jffs2_security_xattr_handler;
 925                 break;
 926 #endif
 927 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 928         case JFFS2_XPREFIX_ACL_ACCESS:
 929                 ret = &jffs2_acl_access_xattr_handler;
 930                 break;
 931         case JFFS2_XPREFIX_ACL_DEFAULT:
 932                 ret = &jffs2_acl_default_xattr_handler;
 933                 break;
 934 #endif
 935         case JFFS2_XPREFIX_TRUSTED:
 936                 ret = &jffs2_trusted_xattr_handler;
 937                 break;
 938         default:
 939                 ret = NULL;
 940                 break;
 941         }
 942         return ret;
 943 }
 944
 945 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 946 {
 947         struct inode *inode = dentry->d_inode;
 948         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 949         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 950         struct jffs2_inode_cache *ic = f->inocache;
 951         struct jffs2_xattr_ref *ref, **pref;
 952         struct jffs2_xattr_datum *xd;
 953         struct xattr_handler *xhandle;
 954         ssize_t len, rc;
 955         int retry = 0;
 956
 957         rc = check_xattr_ref_inode(c, ic);
 958         if (unlikely(rc))
 959                 return rc;
 960
 961         down_read(&c->xattr_sem);
 962  retry:
 963         len = 0;
 964         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 965                 BUG_ON(ref->ic != ic);
 966                 xd = ref->xd;
 967                 if (!xd->xname) {
 968                         /* xdatum is unchached */
 969                         if (!retry) {
 970                                 retry = 1;
 971                                 up_read(&c->xattr_sem);
 972                                 down_write(&c->xattr_sem);
 973                                 goto retry;
 974                         } else {
 975                                 rc = load_xattr_datum(c, xd);
 976                                 if (unlikely(rc > 0)) {
 977                                         *pref = ref->next;
 978                                         delete_xattr_ref(c, ref);
 979                                         goto retry;
 980                                 } else if (unlikely(rc < 0))
 981                                         goto out;
 982                         }
 983                 }
 984                 xhandle = xprefix_to_handler(xd->xprefix);
 985                 if (!xhandle)
 986                         continue;
 987                 if (buffer) {
 988                         rc = xhandle->list(inode, buffer+len, size-len, xd->xname, xd->name_len);
 989                 } else {
 990                         rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
 991                 }
 992                 if (rc < 0)
 993                         goto out;
 994                 len += rc;
 995         }
 996         rc = len;
 997  out:
 998         if (!retry) {
 999                 up_read(&c->xattr_sem);
1000         } else {
1001                 up_write(&c->xattr_sem);
1002         }
1003         return rc;
1004 }
1005
1006 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1007                       char *buffer, size_t size)
1008 {
1009         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1010         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1011         struct jffs2_inode_cache *ic = f->inocache;
1012         struct jffs2_xattr_datum *xd;
1013         struct jffs2_xattr_ref *ref, **pref;
1014         int rc, retry = 0;
1015
1016         rc = check_xattr_ref_inode(c, ic);
1017         if (unlikely(rc))
1018                 return rc;
1019
1020         down_read(&c->xattr_sem);
1021  retry:
1022         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1023                 BUG_ON(ref->ic!=ic);
1024
1025                 xd = ref->xd;
1026                 if (xd->xprefix != xprefix)
1027                         continue;
1028                 if (!xd->xname) {
1029                         /* xdatum is unchached */
1030                         if (!retry) {
1031                                 retry = 1;
1032                                 up_read(&c->xattr_sem);
1033                                 down_write(&c->xattr_sem);
1034                                 goto retry;
1035                         } else {
1036                                 rc = load_xattr_datum(c, xd);
1037                                 if (unlikely(rc > 0)) {
1038                                         *pref = ref->next;
1039                                         delete_xattr_ref(c, ref);
1040                                         goto retry;
1041                                 } else if (unlikely(rc < 0)) {
1042                                         goto out;
1043                                 }
1044                         }
1045                 }
1046                 if (!strcmp(xname, xd->xname)) {
1047                         rc = xd->value_len;
1048                         if (buffer) {
1049                                 if (size < rc) {
1050                                         rc = -ERANGE;
1051                                 } else {
1052                                         memcpy(buffer, xd->xvalue, rc);
1053                                 }
1054                         }
1055                         goto out;
1056                 }
1057         }
1058         rc = -ENODATA;
1059  out:
1060         if (!retry) {
1061                 up_read(&c->xattr_sem);
1062         } else {
1063                 up_write(&c->xattr_sem);
1064         }
1065         return rc;
1066 }
1067
1068 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1069                       const char *buffer, size_t size, int flags)
1070 {
1071         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1072         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1073         struct jffs2_inode_cache *ic = f->inocache;
1074         struct jffs2_xattr_datum *xd;
1075         struct jffs2_xattr_ref *ref, *newref, **pref;
1076         uint32_t length, request;
1077         int rc;
1078
1079         rc = check_xattr_ref_inode(c, ic);
1080         if (unlikely(rc))
1081                 return rc;
1082
1083         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1084         rc = jffs2_reserve_space(c, request, &length,
1085                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1086         if (rc) {
1087                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1088                 return rc;
1089         }
1090
1091         /* Find existing xattr */
1092         down_write(&c->xattr_sem);
1093  retry:
1094         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1095                 xd = ref->xd;
1096                 if (xd->xprefix != xprefix)
1097                         continue;
1098                 if (!xd->xname) {
1099                         rc = load_xattr_datum(c, xd);
1100                         if (unlikely(rc > 0)) {
1101                                 *pref = ref->next;
1102                                 delete_xattr_ref(c, ref);
1103                                 goto retry;
1104                         } else if (unlikely(rc < 0))
1105                                 goto out;
1106                 }
1107                 if (!strcmp(xd->xname, xname)) {
1108                         if (flags & XATTR_CREATE) {
1109                                 rc = -EEXIST;
1110                                 goto out;
1111                         }
1112                         if (!buffer) {
1113                                 ref->ino = ic->ino;
1114                                 ref->xid = xd->xid;
1115                                 ref->xseqno |= XREF_DELETE_MARKER;
1116                                 rc = save_xattr_ref(c, ref);
1117                                 if (!rc) {
1118                                         *pref = ref->next;
1119                                         spin_lock(&c->erase_completion_lock);
1120                                         ref->next = c->xref_dead_list;
1121                                         c->xref_dead_list = ref;
1122                                         spin_unlock(&c->erase_completion_lock);
1123                                         unrefer_xattr_datum(c, xd);
1124                                 } else {
1125                                         ref->ic = ic;
1126                                         ref->xd = xd;
1127                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1128                                 }
1129                                 goto out;
1130                         }
1131                         goto found;
1132                 }
1133         }
1134         /* not found */
1135         if (flags & XATTR_REPLACE) {
1136                 rc = -ENODATA;
1137                 goto out;
1138         }
1139         if (!buffer) {
1140                 rc = -ENODATA;
1141                 goto out;
1142         }
1143  found:
1144         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1145         if (IS_ERR(xd)) {
1146                 rc = PTR_ERR(xd);
1147                 goto out;
1148         }
1149         up_write(&c->xattr_sem);
1150         jffs2_complete_reservation(c);
1151
1152         /* create xattr_ref */
1153         request = PAD(sizeof(struct jffs2_raw_xref));
1154         rc = jffs2_reserve_space(c, request, &length,
1155                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1156         down_write(&c->xattr_sem);
1157         if (rc) {
1158                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1159                 unrefer_xattr_datum(c, xd);
1160                 up_write(&c->xattr_sem);
1161                 return rc;
1162         }
1163         if (ref)
1164                 *pref = ref->next;
1165         newref = create_xattr_ref(c, ic, xd);
1166         if (IS_ERR(newref)) {
1167                 if (ref) {
1168                         ref->next = ic->xref;
1169                         ic->xref = ref;
1170                 }
1171                 rc = PTR_ERR(newref);
1172                 unrefer_xattr_datum(c, xd);
1173         } else if (ref) {
1174                 delete_xattr_ref(c, ref);
1175         }
1176  out:
1177         up_write(&c->xattr_sem);
1178         jffs2_complete_reservation(c);
1179         return rc;
1180 }
1181
1182 /* -------- garbage collector functions -------------
1183  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1184  *   is used to move xdatum into new node.
1185  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1186  *   is used to move xref into new node.
1187  * jffs2_verify_xattr(c)
1188  *   is used to call do_verify_xattr_datum() before garbage collecting.
1189  * jffs2_release_xattr_datum(c, xd)
1190  *   is used to release an in-memory object of xdatum.
1191  * jffs2_release_xattr_ref(c, ref)
1192  *   is used to release an in-memory object of xref.
1193  * -------------------------------------------------- */
1194 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1195                                       struct jffs2_raw_node_ref *raw)
1196 {
1197         uint32_t totlen, length, old_ofs;
1198         int rc = 0;
1199
1200         down_write(&c->xattr_sem);
1201         if (xd->node != raw)
1202                 goto out;
1203         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1204                 goto out;
1205
1206         rc = load_xattr_datum(c, xd);
1207         if (unlikely(rc)) {
1208                 rc = (rc > 0) ? 0 : rc;
1209                 goto out;
1210         }
1211         old_ofs = ref_offset(xd->node);
1212         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1213                         + xd->name_len + 1 + xd->value_len);
1214         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1215         if (rc) {
1216                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1217                 goto out;
1218         }
1219         rc = save_xattr_datum(c, xd);
1220         if (!rc)
1221                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1222                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1223  out:
1224         if (!rc)
1225                 jffs2_mark_node_obsolete(c, raw);
1226         up_write(&c->xattr_sem);
1227         return rc;
1228 }
1229
1230 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1231                                     struct jffs2_raw_node_ref *raw)
1232 {
1233         uint32_t totlen, length, old_ofs;
1234         int rc = 0;
1235
1236         down_write(&c->xattr_sem);
1237         BUG_ON(!ref->node);
1238
1239         if (ref->node != raw)
1240                 goto out;
1241         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1242                 goto out;
1243
1244         old_ofs = ref_offset(ref->node);
1245         totlen = ref_totlen(c, c->gcblock, ref->node);
1246
1247         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1248         if (rc) {
1249                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1250                               __FUNCTION__, rc, totlen);
1251                 rc = rc ? rc : -EBADFD;
1252                 goto out;
1253         }
1254         rc = save_xattr_ref(c, ref);
1255         if (!rc)
1256                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1257                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1258  out:
1259         if (!rc)
1260                 jffs2_mark_node_obsolete(c, raw);
1261         up_write(&c->xattr_sem);
1262         return rc;
1263 }
1264
1265 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1266 {
1267         struct jffs2_xattr_datum *xd, *_xd;
1268         struct jffs2_eraseblock *jeb;
1269         struct jffs2_raw_node_ref *raw;
1270         uint32_t totlen;
1271         int rc;
1272
1273         down_write(&c->xattr_sem);
1274         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1275                 rc = do_verify_xattr_datum(c, xd);
1276                 if (rc < 0)
1277                         continue;
1278                 list_del_init(&xd->xindex);
1279                 spin_lock(&c->erase_completion_lock);
1280                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1281                         if (ref_flags(raw) != REF_UNCHECKED)
1282                                 continue;
1283                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1284                         totlen = PAD(ref_totlen(c, jeb, raw));
1285                         c->unchecked_size -= totlen; c->used_size += totlen;
1286                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1287                         raw->flash_offset = ref_offset(raw)
1288                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1289                 }
1290                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1291                         list_add(&xd->xindex, &c->xattr_dead_list);
1292                 spin_unlock(&c->erase_completion_lock);
1293         }
1294         up_write(&c->xattr_sem);
1295         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1296 }
1297
1298 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1299 {
1300         /* must be called under spin_lock(&c->erase_completion_lock) */
1301         if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1302                 return;
1303
1304         list_del(&xd->xindex);
1305         jffs2_free_xattr_datum(xd);
1306 }
1307
1308 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1309 {
1310         /* must be called under spin_lock(&c->erase_completion_lock) */
1311         struct jffs2_xattr_ref *tmp, **ptmp;
1312
1313         if (ref->node != (void *)ref)
1314                 return;
1315
1316         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1317                 if (ref == tmp) {
1318                         *ptmp = tmp->next;
1319                         break;
1320                 }
1321         }
1322         jffs2_free_xattr_ref(ref);
1323 }