git.oblomov.eu Git - linux-2.6/blob - fs/jffs2/xattr.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 2006  NEC Corporation
   5  *
   6  * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/fs.h>
  14 #include <linux/time.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/highmem.h>
  17 #include <linux/crc32.h>
  18 #include <linux/jffs2.h>
  19 #include <linux/xattr.h>
  20 #include <linux/mtd/mtd.h>
  21 #include "nodelist.h"
  22 /* -------- xdatum related functions ----------------
  23  * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  24  *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  25  *   the index of the xattr name/value pair cache (c->xattrindex).
  26  * is_xattr_datum_unchecked(c, xd)
  27  *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  28  *   unchecked, it returns 0.
  29  * unload_xattr_datum(c, xd)
  30  *   is used to release xattr name/value pair and detach from c->xattrindex.
  31  * reclaim_xattr_datum(c)
  32  *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  33  *   memory usage by cache is over c->xdatum_mem_threshold. Currentry, this threshold
  34  *   is hard coded as 32KiB.
  35  * do_verify_xattr_datum(c, xd)
  36  *   is used to load the xdatum informations without name/value pair from the medium.
  37  *   It's necessary once, because those informations are not collected during mounting
  38  *   process when EBS is enabled.
  39  *   0 will be returned, if success. An negative return value means recoverable error, and
  40  *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  41  *   and xref when it returned positive value.
  42  * do_load_xattr_datum(c, xd)
  43  *   is used to load name/value pair from the medium.
  44  *   The meanings of return value is same as do_verify_xattr_datum().
  45  * load_xattr_datum(c, xd)
  46  *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  47  *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  48  *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  49  * save_xattr_datum(c, xd)
  50  *   is used to write xdatum to medium. xd->version will be incremented.
  51  * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  52  *   is used to create new xdatum and write to medium.
  53  * 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                 uint32_t xid = xd->xid, version = xd->version;
 403
 404                 unload_xattr_datum(c, xd);
 405                 xd->flags |= JFFS2_XFLAGS_DEAD;
 406                 if (xd->node == (void *)xd) {
 407                         BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 408                         jffs2_free_xattr_datum(xd);
 409                 } else {
 410                         list_add(&xd->xindex, &c->xattr_dead_list);
 411                 }
 412                 spin_unlock(&c->erase_completion_lock);
 413
 414                 dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n", xid, version);
 415         }
 416 }
 417
 418 /* -------- xref related functions ------------------
 419  * verify_xattr_ref(c, ref)
 420  *   is used to load xref information from medium. Because summary data does not
 421  *   contain xid/ino, it's necessary to verify once while mounting process.
 422  * save_xattr_ref(c, ref)
 423  *   is used to write xref to medium. If delete marker is marked, it write
 424  *   a delete marker of xref into medium.
 425  * create_xattr_ref(c, ic, xd)
 426  *   is used to create a new xref and write to medium.
 427  * delete_xattr_ref(c, ref)
 428  *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 429  *   and allows GC to reclaim those physical nodes.
 430  * jffs2_xattr_delete_inode(c, ic)
 431  *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 432  * jffs2_xattr_free_inode(c, ic)
 433  *   is called to release xattr related objects when unmounting.
 434  * check_xattr_ref_inode(c, ic)
 435  *   is used to confirm inode does not have duplicate xattr name/value pair.
 436  * -------------------------------------------------- */
 437 static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 438 {
 439         struct jffs2_eraseblock *jeb;
 440         struct jffs2_raw_node_ref *raw;
 441         struct jffs2_raw_xref rr;
 442         size_t readlen;
 443         uint32_t crc, offset, totlen;
 444         int rc;
 445
 446         spin_lock(&c->erase_completion_lock);
 447         if (ref_flags(ref->node) != REF_UNCHECKED)
 448                 goto complete;
 449         offset = ref_offset(ref->node);
 450         spin_unlock(&c->erase_completion_lock);
 451
 452         rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
 453         if (rc || sizeof(rr) != readlen) {
 454                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
 455                               rc, sizeof(rr), readlen, offset);
 456                 return rc ? rc : -EIO;
 457         }
 458         /* obsolete node */
 459         crc = crc32(0, &rr, sizeof(rr) - 4);
 460         if (crc != je32_to_cpu(rr.node_crc)) {
 461                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 462                             offset, je32_to_cpu(rr.node_crc), crc);
 463                 return EIO;
 464         }
 465         if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 466             || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 467             || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 468                 JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 469                             "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
 470                             offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 471                             je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 472                             je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 473                 return EIO;
 474         }
 475         ref->ino = je32_to_cpu(rr.ino);
 476         ref->xid = je32_to_cpu(rr.xid);
 477         ref->xseqno = je32_to_cpu(rr.xseqno);
 478         if (ref->xseqno > c->highest_xseqno)
 479                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 480
 481         spin_lock(&c->erase_completion_lock);
 482  complete:
 483         for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
 484                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 485                 totlen = PAD(ref_totlen(c, jeb, raw));
 486                 if (ref_flags(raw) == REF_UNCHECKED) {
 487                         c->unchecked_size -= totlen; c->used_size += totlen;
 488                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 489                 }
 490                 raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
 491         }
 492         spin_unlock(&c->erase_completion_lock);
 493
 494         dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 495                   ref->ino, ref->xid, ref_offset(ref->node));
 496         return 0;
 497 }
 498
 499 static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 500 {
 501         /* must be called under down_write(xattr_sem) */
 502         struct jffs2_raw_xref rr;
 503         size_t length;
 504         uint32_t xseqno, phys_ofs = write_ofs(c);
 505         int ret;
 506
 507         rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 508         rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 509         rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 510         rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 511
 512         xseqno = (c->highest_xseqno += 2);
 513         if (is_xattr_ref_dead(ref)) {
 514                 xseqno |= XREF_DELETE_MARKER;
 515                 rr.ino = cpu_to_je32(ref->ino);
 516                 rr.xid = cpu_to_je32(ref->xid);
 517         } else {
 518                 rr.ino = cpu_to_je32(ref->ic->ino);
 519                 rr.xid = cpu_to_je32(ref->xd->xid);
 520         }
 521         rr.xseqno = cpu_to_je32(xseqno);
 522         rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 523
 524         ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 525         if (ret || sizeof(rr) != length) {
 526                 JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
 527                               ret, sizeof(rr), length, phys_ofs);
 528                 ret = ret ? ret : -EIO;
 529                 if (length)
 530                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
 531
 532                 return ret;
 533         }
 534         /* success */
 535         ref->xseqno = xseqno;
 536         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
 537
 538         dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 539
 540         return 0;
 541 }
 542
 543 static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 544                                                 struct jffs2_xattr_datum *xd)
 545 {
 546         /* must be called under down_write(xattr_sem) */
 547         struct jffs2_xattr_ref *ref;
 548         int ret;
 549
 550         ref = jffs2_alloc_xattr_ref();
 551         if (!ref)
 552                 return ERR_PTR(-ENOMEM);
 553         ref->ic = ic;
 554         ref->xd = xd;
 555
 556         ret = save_xattr_ref(c, ref);
 557         if (ret) {
 558                 jffs2_free_xattr_ref(ref);
 559                 return ERR_PTR(ret);
 560         }
 561
 562         /* Chain to inode */
 563         ref->next = ic->xref;
 564         ic->xref = ref;
 565
 566         return ref; /* success */
 567 }
 568
 569 static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 570 {
 571         /* must be called under down_write(xattr_sem) */
 572         struct jffs2_xattr_datum *xd;
 573
 574         xd = ref->xd;
 575         ref->xseqno |= XREF_DELETE_MARKER;
 576         ref->ino = ref->ic->ino;
 577         ref->xid = ref->xd->xid;
 578         spin_lock(&c->erase_completion_lock);
 579         ref->next = c->xref_dead_list;
 580         c->xref_dead_list = ref;
 581         spin_unlock(&c->erase_completion_lock);
 582
 583         dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
 584                   ref->ino, ref->xid, ref->xseqno);
 585
 586         unrefer_xattr_datum(c, xd);
 587 }
 588
 589 void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 590 {
 591         /* It's called from jffs2_clear_inode() on inode removing.
 592            When an inode with XATTR is removed, those XATTRs must be removed. */
 593         struct jffs2_xattr_ref *ref, *_ref;
 594
 595         if (!ic || ic->nlink > 0)
 596                 return;
 597
 598         down_write(&c->xattr_sem);
 599         for (ref = ic->xref; ref; ref = _ref) {
 600                 _ref = ref->next;
 601                 delete_xattr_ref(c, ref);
 602         }
 603         ic->xref = NULL;
 604         up_write(&c->xattr_sem);
 605 }
 606
 607 void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 608 {
 609         /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 610         struct jffs2_xattr_datum *xd;
 611         struct jffs2_xattr_ref *ref, *_ref;
 612
 613         down_write(&c->xattr_sem);
 614         for (ref = ic->xref; ref; ref = _ref) {
 615                 _ref = ref->next;
 616                 xd = ref->xd;
 617                 if (atomic_dec_and_test(&xd->refcnt)) {
 618                         unload_xattr_datum(c, xd);
 619                         jffs2_free_xattr_datum(xd);
 620                 }
 621                 jffs2_free_xattr_ref(ref);
 622         }
 623         ic->xref = NULL;
 624         up_write(&c->xattr_sem);
 625 }
 626
 627 static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 628 {
 629         /* success of check_xattr_ref_inode() means taht inode (ic) dose not have
 630          * duplicate name/value pairs. If duplicate name/value pair would be found,
 631          * one will be removed.
 632          */
 633         struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 634         int rc = 0;
 635
 636         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 637                 return 0;
 638         down_write(&c->xattr_sem);
 639  retry:
 640         rc = 0;
 641         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 642                 if (!ref->xd->xname) {
 643                         rc = load_xattr_datum(c, ref->xd);
 644                         if (unlikely(rc > 0)) {
 645                                 *pref = ref->next;
 646                                 delete_xattr_ref(c, ref);
 647                                 goto retry;
 648                         } else if (unlikely(rc < 0))
 649                                 goto out;
 650                 }
 651                 for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 652                         if (!cmp->xd->xname) {
 653                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
 654                                 rc = load_xattr_datum(c, cmp->xd);
 655                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 656                                 if (unlikely(rc > 0)) {
 657                                         *pcmp = cmp->next;
 658                                         delete_xattr_ref(c, cmp);
 659                                         goto retry;
 660                                 } else if (unlikely(rc < 0))
 661                                         goto out;
 662                         }
 663                         if (ref->xd->xprefix == cmp->xd->xprefix
 664                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 665                                 if (ref->xseqno > cmp->xseqno) {
 666                                         *pcmp = cmp->next;
 667                                         delete_xattr_ref(c, cmp);
 668                                 } else {
 669                                         *pref = ref->next;
 670                                         delete_xattr_ref(c, ref);
 671                                 }
 672                                 goto retry;
 673                         }
 674                 }
 675         }
 676         ic->flags |= INO_FLAGS_XATTR_CHECKED;
 677  out:
 678         up_write(&c->xattr_sem);
 679
 680         return rc;
 681 }
 682
 683 /* -------- xattr subsystem functions ---------------
 684  * jffs2_init_xattr_subsystem(c)
 685  *   is used to initialize semaphore and list_head, and some variables.
 686  * jffs2_find_xattr_datum(c, xid)
 687  *   is used to lookup xdatum while scanning process.
 688  * jffs2_clear_xattr_subsystem(c)
 689  *   is used to release any xattr related objects.
 690  * jffs2_build_xattr_subsystem(c)
 691  *   is used to associate xdatum and xref while super block building process.
 692  * jffs2_setup_xattr_datum(c, xid, version)
 693  *   is used to insert xdatum while scanning process.
 694  * -------------------------------------------------- */
 695 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 696 {
 697         int i;
 698
 699         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 700                 INIT_LIST_HEAD(&c->xattrindex[i]);
 701         INIT_LIST_HEAD(&c->xattr_unchecked);
 702         INIT_LIST_HEAD(&c->xattr_dead_list);
 703         c->xref_dead_list = NULL;
 704         c->xref_temp = NULL;
 705
 706         init_rwsem(&c->xattr_sem);
 707         c->highest_xid = 0;
 708         c->highest_xseqno = 0;
 709         c->xdatum_mem_usage = 0;
 710         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 711 }
 712
 713 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 714 {
 715         struct jffs2_xattr_datum *xd;
 716         int i = xid % XATTRINDEX_HASHSIZE;
 717
 718         /* It's only used in scanning/building process. */
 719         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 720
 721         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 722                 if (xd->xid==xid)
 723                         return xd;
 724         }
 725         return NULL;
 726 }
 727
 728 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 729 {
 730         struct jffs2_xattr_datum *xd, *_xd;
 731         struct jffs2_xattr_ref *ref, *_ref;
 732         int i;
 733
 734         for (ref=c->xref_temp; ref; ref = _ref) {
 735                 _ref = ref->next;
 736                 jffs2_free_xattr_ref(ref);
 737         }
 738
 739         for (ref=c->xref_dead_list; ref; ref = _ref) {
 740                 _ref = ref->next;
 741                 jffs2_free_xattr_ref(ref);
 742         }
 743
 744         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 745                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 746                         list_del(&xd->xindex);
 747                         if (xd->xname)
 748                                 kfree(xd->xname);
 749                         jffs2_free_xattr_datum(xd);
 750                 }
 751         }
 752
 753         list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
 754                 list_del(&xd->xindex);
 755                 jffs2_free_xattr_datum(xd);
 756         }
 757 }
 758
 759 #define XREF_TMPHASH_SIZE       (128)
 760 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 761 {
 762         struct jffs2_xattr_ref *ref, *_ref;
 763         struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
 764         struct jffs2_xattr_datum *xd, *_xd;
 765         struct jffs2_inode_cache *ic;
 766         struct jffs2_raw_node_ref *raw;
 767         int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
 768         int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
 769
 770         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 771
 772         /* Phase.1 : Merge same xref */
 773         for (i=0; i < XREF_TMPHASH_SIZE; i++)
 774                 xref_tmphash[i] = NULL;
 775         for (ref=c->xref_temp; ref; ref=_ref) {
 776                 struct jffs2_xattr_ref *tmp;
 777
 778                 _ref = ref->next;
 779                 if (ref_flags(ref->node) != REF_PRISTINE) {
 780                         if (verify_xattr_ref(c, ref)) {
 781                                 BUG_ON(ref->node->next_in_ino != (void *)ref);
 782                                 ref->node->next_in_ino = NULL;
 783                                 jffs2_mark_node_obsolete(c, ref->node);
 784                                 jffs2_free_xattr_ref(ref);
 785                                 continue;
 786                         }
 787                 }
 788
 789                 i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
 790                 for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
 791                         if (tmp->ino == ref->ino && tmp->xid == ref->xid)
 792                                 break;
 793                 }
 794                 if (tmp) {
 795                         raw = ref->node;
 796                         if (ref->xseqno > tmp->xseqno) {
 797                                 tmp->xseqno = ref->xseqno;
 798                                 raw->next_in_ino = tmp->node;
 799                                 tmp->node = raw;
 800                         } else {
 801                                 raw->next_in_ino = tmp->node->next_in_ino;
 802                                 tmp->node->next_in_ino = raw;
 803                         }
 804                         jffs2_free_xattr_ref(ref);
 805                         continue;
 806                 } else {
 807                         ref->next = xref_tmphash[i];
 808                         xref_tmphash[i] = ref;
 809                 }
 810         }
 811         c->xref_temp = NULL;
 812
 813         /* Phase.2 : Bind xref with inode_cache and xattr_datum */
 814         for (i=0; i < XREF_TMPHASH_SIZE; i++) {
 815                 for (ref=xref_tmphash[i]; ref; ref=_ref) {
 816                         xref_count++;
 817                         _ref = ref->next;
 818                         if (is_xattr_ref_dead(ref)) {
 819                                 ref->next = c->xref_dead_list;
 820                                 c->xref_dead_list = ref;
 821                                 xref_dead_count++;
 822                                 continue;
 823                         }
 824                         /* At this point, ref->xid and ref->ino contain XID and inode number.
 825                            ref->xd and ref->ic are not valid yet. */
 826                         xd = jffs2_find_xattr_datum(c, ref->xid);
 827                         ic = jffs2_get_ino_cache(c, ref->ino);
 828                         if (!xd || !ic) {
 829                                 dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
 830                                           ref->ino, ref->xid, ref->xseqno);
 831                                 ref->xseqno |= XREF_DELETE_MARKER;
 832                                 ref->next = c->xref_dead_list;
 833                                 c->xref_dead_list = ref;
 834                                 xref_orphan_count++;
 835                                 continue;
 836                         }
 837                         ref->xd = xd;
 838                         ref->ic = ic;
 839                         atomic_inc(&xd->refcnt);
 840                         ref->next = ic->xref;
 841                         ic->xref = ref;
 842                 }
 843         }
 844
 845         /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
 846         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 847                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 848                         xdatum_count++;
 849                         list_del_init(&xd->xindex);
 850                         if (!atomic_read(&xd->refcnt)) {
 851                                 dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
 852                                           xd->xid, xd->version);
 853                                 xd->flags |= JFFS2_XFLAGS_DEAD;
 854                                 list_add(&xd->xindex, &c->xattr_unchecked);
 855                                 xdatum_orphan_count++;
 856                                 continue;
 857                         }
 858                         if (is_xattr_datum_unchecked(c, xd)) {
 859                                 dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
 860                                           xd->xid, xd->version);
 861                                 list_add(&xd->xindex, &c->xattr_unchecked);
 862                                 xdatum_unchecked_count++;
 863                         }
 864                 }
 865         }
 866         /* build complete */
 867         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
 868                      " (%u unchecked, %u orphan) and "
 869                      "%u of xref (%u dead, %u orphan) found.\n",
 870                      xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
 871                      xref_count, xref_dead_count, xref_orphan_count);
 872 }
 873
 874 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 875                                                   uint32_t xid, uint32_t version)
 876 {
 877         struct jffs2_xattr_datum *xd;
 878
 879         xd = jffs2_find_xattr_datum(c, xid);
 880         if (!xd) {
 881                 xd = jffs2_alloc_xattr_datum();
 882                 if (!xd)
 883                         return ERR_PTR(-ENOMEM);
 884                 xd->xid = xid;
 885                 xd->version = version;
 886                 if (xd->xid > c->highest_xid)
 887                         c->highest_xid = xd->xid;
 888                 list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 889         }
 890         return xd;
 891 }
 892
 893 /* -------- xattr subsystem functions ---------------
 894  * xprefix_to_handler(xprefix)
 895  *   is used to translate xprefix into xattr_handler.
 896  * jffs2_listxattr(dentry, buffer, size)
 897  *   is an implementation of listxattr handler on jffs2.
 898  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 899  *   is an implementation of getxattr handler on jffs2.
 900  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 901  *   is an implementation of setxattr handler on jffs2.
 902  * -------------------------------------------------- */
 903 struct xattr_handler *jffs2_xattr_handlers[] = {
 904         &jffs2_user_xattr_handler,
 905 #ifdef CONFIG_JFFS2_FS_SECURITY
 906         &jffs2_security_xattr_handler,
 907 #endif
 908 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 909         &jffs2_acl_access_xattr_handler,
 910         &jffs2_acl_default_xattr_handler,
 911 #endif
 912         &jffs2_trusted_xattr_handler,
 913         NULL
 914 };
 915
 916 static struct xattr_handler *xprefix_to_handler(int xprefix) {
 917         struct xattr_handler *ret;
 918
 919         switch (xprefix) {
 920         case JFFS2_XPREFIX_USER:
 921                 ret = &jffs2_user_xattr_handler;
 922                 break;
 923 #ifdef CONFIG_JFFS2_FS_SECURITY
 924         case JFFS2_XPREFIX_SECURITY:
 925                 ret = &jffs2_security_xattr_handler;
 926                 break;
 927 #endif
 928 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 929         case JFFS2_XPREFIX_ACL_ACCESS:
 930                 ret = &jffs2_acl_access_xattr_handler;
 931                 break;
 932         case JFFS2_XPREFIX_ACL_DEFAULT:
 933                 ret = &jffs2_acl_default_xattr_handler;
 934                 break;
 935 #endif
 936         case JFFS2_XPREFIX_TRUSTED:
 937                 ret = &jffs2_trusted_xattr_handler;
 938                 break;
 939         default:
 940                 ret = NULL;
 941                 break;
 942         }
 943         return ret;
 944 }
 945
 946 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 947 {
 948         struct inode *inode = dentry->d_inode;
 949         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 950         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 951         struct jffs2_inode_cache *ic = f->inocache;
 952         struct jffs2_xattr_ref *ref, **pref;
 953         struct jffs2_xattr_datum *xd;
 954         struct xattr_handler *xhandle;
 955         ssize_t len, rc;
 956         int retry = 0;
 957
 958         rc = check_xattr_ref_inode(c, ic);
 959         if (unlikely(rc))
 960                 return rc;
 961
 962         down_read(&c->xattr_sem);
 963  retry:
 964         len = 0;
 965         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 966                 BUG_ON(ref->ic != ic);
 967                 xd = ref->xd;
 968                 if (!xd->xname) {
 969                         /* xdatum is unchached */
 970                         if (!retry) {
 971                                 retry = 1;
 972                                 up_read(&c->xattr_sem);
 973                                 down_write(&c->xattr_sem);
 974                                 goto retry;
 975                         } else {
 976                                 rc = load_xattr_datum(c, xd);
 977                                 if (unlikely(rc > 0)) {
 978                                         *pref = ref->next;
 979                                         delete_xattr_ref(c, ref);
 980                                         goto retry;
 981                                 } else if (unlikely(rc < 0))
 982                                         goto out;
 983                         }
 984                 }
 985                 xhandle = xprefix_to_handler(xd->xprefix);
 986                 if (!xhandle)
 987                         continue;
 988                 if (buffer) {
 989                         rc = xhandle->list(inode, buffer+len, size-len, xd->xname, xd->name_len);
 990                 } else {
 991                         rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
 992                 }
 993                 if (rc < 0)
 994                         goto out;
 995                 len += rc;
 996         }
 997         rc = len;
 998  out:
 999         if (!retry) {
1000                 up_read(&c->xattr_sem);
1001         } else {
1002                 up_write(&c->xattr_sem);
1003         }
1004         return rc;
1005 }
1006
1007 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1008                       char *buffer, size_t size)
1009 {
1010         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1011         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1012         struct jffs2_inode_cache *ic = f->inocache;
1013         struct jffs2_xattr_datum *xd;
1014         struct jffs2_xattr_ref *ref, **pref;
1015         int rc, retry = 0;
1016
1017         rc = check_xattr_ref_inode(c, ic);
1018         if (unlikely(rc))
1019                 return rc;
1020
1021         down_read(&c->xattr_sem);
1022  retry:
1023         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1024                 BUG_ON(ref->ic!=ic);
1025
1026                 xd = ref->xd;
1027                 if (xd->xprefix != xprefix)
1028                         continue;
1029                 if (!xd->xname) {
1030                         /* xdatum is unchached */
1031                         if (!retry) {
1032                                 retry = 1;
1033                                 up_read(&c->xattr_sem);
1034                                 down_write(&c->xattr_sem);
1035                                 goto retry;
1036                         } else {
1037                                 rc = load_xattr_datum(c, xd);
1038                                 if (unlikely(rc > 0)) {
1039                                         *pref = ref->next;
1040                                         delete_xattr_ref(c, ref);
1041                                         goto retry;
1042                                 } else if (unlikely(rc < 0)) {
1043                                         goto out;
1044                                 }
1045                         }
1046                 }
1047                 if (!strcmp(xname, xd->xname)) {
1048                         rc = xd->value_len;
1049                         if (buffer) {
1050                                 if (size < rc) {
1051                                         rc = -ERANGE;
1052                                 } else {
1053                                         memcpy(buffer, xd->xvalue, rc);
1054                                 }
1055                         }
1056                         goto out;
1057                 }
1058         }
1059         rc = -ENODATA;
1060  out:
1061         if (!retry) {
1062                 up_read(&c->xattr_sem);
1063         } else {
1064                 up_write(&c->xattr_sem);
1065         }
1066         return rc;
1067 }
1068
1069 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1070                       const char *buffer, size_t size, int flags)
1071 {
1072         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1073         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1074         struct jffs2_inode_cache *ic = f->inocache;
1075         struct jffs2_xattr_datum *xd;
1076         struct jffs2_xattr_ref *ref, *newref, **pref;
1077         uint32_t length, request;
1078         int rc;
1079
1080         rc = check_xattr_ref_inode(c, ic);
1081         if (unlikely(rc))
1082                 return rc;
1083
1084         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1085         rc = jffs2_reserve_space(c, request, &length,
1086                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1087         if (rc) {
1088                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1089                 return rc;
1090         }
1091
1092         /* Find existing xattr */
1093         down_write(&c->xattr_sem);
1094  retry:
1095         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1096                 xd = ref->xd;
1097                 if (xd->xprefix != xprefix)
1098                         continue;
1099                 if (!xd->xname) {
1100                         rc = load_xattr_datum(c, xd);
1101                         if (unlikely(rc > 0)) {
1102                                 *pref = ref->next;
1103                                 delete_xattr_ref(c, ref);
1104                                 goto retry;
1105                         } else if (unlikely(rc < 0))
1106                                 goto out;
1107                 }
1108                 if (!strcmp(xd->xname, xname)) {
1109                         if (flags & XATTR_CREATE) {
1110                                 rc = -EEXIST;
1111                                 goto out;
1112                         }
1113                         if (!buffer) {
1114                                 ref->ino = ic->ino;
1115                                 ref->xid = xd->xid;
1116                                 ref->xseqno |= XREF_DELETE_MARKER;
1117                                 rc = save_xattr_ref(c, ref);
1118                                 if (!rc) {
1119                                         *pref = ref->next;
1120                                         spin_lock(&c->erase_completion_lock);
1121                                         ref->next = c->xref_dead_list;
1122                                         c->xref_dead_list = ref;
1123                                         spin_unlock(&c->erase_completion_lock);
1124                                         unrefer_xattr_datum(c, xd);
1125                                 } else {
1126                                         ref->ic = ic;
1127                                         ref->xd = xd;
1128                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1129                                 }
1130                                 goto out;
1131                         }
1132                         goto found;
1133                 }
1134         }
1135         /* not found */
1136         if (flags & XATTR_REPLACE) {
1137                 rc = -ENODATA;
1138                 goto out;
1139         }
1140         if (!buffer) {
1141                 rc = -ENODATA;
1142                 goto out;
1143         }
1144  found:
1145         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1146         if (IS_ERR(xd)) {
1147                 rc = PTR_ERR(xd);
1148                 goto out;
1149         }
1150         up_write(&c->xattr_sem);
1151         jffs2_complete_reservation(c);
1152
1153         /* create xattr_ref */
1154         request = PAD(sizeof(struct jffs2_raw_xref));
1155         rc = jffs2_reserve_space(c, request, &length,
1156                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1157         down_write(&c->xattr_sem);
1158         if (rc) {
1159                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1160                 unrefer_xattr_datum(c, xd);
1161                 up_write(&c->xattr_sem);
1162                 return rc;
1163         }
1164         if (ref)
1165                 *pref = ref->next;
1166         newref = create_xattr_ref(c, ic, xd);
1167         if (IS_ERR(newref)) {
1168                 if (ref) {
1169                         ref->next = ic->xref;
1170                         ic->xref = ref;
1171                 }
1172                 rc = PTR_ERR(newref);
1173                 unrefer_xattr_datum(c, xd);
1174         } else if (ref) {
1175                 delete_xattr_ref(c, ref);
1176         }
1177  out:
1178         up_write(&c->xattr_sem);
1179         jffs2_complete_reservation(c);
1180         return rc;
1181 }
1182
1183 /* -------- garbage collector functions -------------
1184  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1185  *   is used to move xdatum into new node.
1186  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1187  *   is used to move xref into new node.
1188  * jffs2_verify_xattr(c)
1189  *   is used to call do_verify_xattr_datum() before garbage collecting.
1190  * jffs2_release_xattr_datum(c, xd)
1191  *   is used to release an in-memory object of xdatum.
1192  * jffs2_release_xattr_ref(c, ref)
1193  *   is used to release an in-memory object of xref.
1194  * -------------------------------------------------- */
1195 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1196                                       struct jffs2_raw_node_ref *raw)
1197 {
1198         uint32_t totlen, length, old_ofs;
1199         int rc = 0;
1200
1201         down_write(&c->xattr_sem);
1202         if (xd->node != raw)
1203                 goto out;
1204         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1205                 goto out;
1206
1207         rc = load_xattr_datum(c, xd);
1208         if (unlikely(rc)) {
1209                 rc = (rc > 0) ? 0 : rc;
1210                 goto out;
1211         }
1212         old_ofs = ref_offset(xd->node);
1213         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1214                         + xd->name_len + 1 + xd->value_len);
1215         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1216         if (rc) {
1217                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1218                 rc = rc ? rc : -EBADFD;
1219                 goto out;
1220         }
1221         rc = save_xattr_datum(c, xd);
1222         if (!rc)
1223                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1224                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1225  out:
1226         if (!rc)
1227                 jffs2_mark_node_obsolete(c, raw);
1228         up_write(&c->xattr_sem);
1229         return rc;
1230 }
1231
1232 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1233                                     struct jffs2_raw_node_ref *raw)
1234 {
1235         uint32_t totlen, length, old_ofs;
1236         int rc = 0;
1237
1238         down_write(&c->xattr_sem);
1239         BUG_ON(!ref->node);
1240
1241         if (ref->node != raw)
1242                 goto out;
1243         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1244                 goto out;
1245
1246         old_ofs = ref_offset(ref->node);
1247         totlen = ref_totlen(c, c->gcblock, ref->node);
1248
1249         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1250         if (rc) {
1251                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1252                               __FUNCTION__, rc, totlen);
1253                 rc = rc ? rc : -EBADFD;
1254                 goto out;
1255         }
1256         rc = save_xattr_ref(c, ref);
1257         if (!rc)
1258                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1259                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1260  out:
1261         if (!rc)
1262                 jffs2_mark_node_obsolete(c, raw);
1263         up_write(&c->xattr_sem);
1264         return rc;
1265 }
1266
1267 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1268 {
1269         struct jffs2_xattr_datum *xd, *_xd;
1270         struct jffs2_eraseblock *jeb;
1271         struct jffs2_raw_node_ref *raw;
1272         uint32_t totlen;
1273         int rc;
1274
1275         down_write(&c->xattr_sem);
1276         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1277                 rc = do_verify_xattr_datum(c, xd);
1278                 if (rc < 0)
1279                         continue;
1280                 list_del_init(&xd->xindex);
1281                 spin_lock(&c->erase_completion_lock);
1282                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1283                         if (ref_flags(raw) != REF_UNCHECKED)
1284                                 continue;
1285                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1286                         totlen = PAD(ref_totlen(c, jeb, raw));
1287                         c->unchecked_size -= totlen; c->used_size += totlen;
1288                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1289                         raw->flash_offset = ref_offset(raw)
1290                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1291                 }
1292                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1293                         list_add(&xd->xindex, &c->xattr_dead_list);
1294                 spin_unlock(&c->erase_completion_lock);
1295         }
1296         up_write(&c->xattr_sem);
1297         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1298 }
1299
1300 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1301 {
1302         /* must be called under spin_lock(&c->erase_completion_lock) */
1303         if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1304                 return;
1305
1306         list_del(&xd->xindex);
1307         jffs2_free_xattr_datum(xd);
1308 }
1309
1310 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1311 {
1312         /* must be called under spin_lock(&c->erase_completion_lock) */
1313         struct jffs2_xattr_ref *tmp, **ptmp;
1314
1315         if (ref->node != (void *)ref)
1316                 return;
1317
1318         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1319                 if (ref == tmp) {
1320                         *ptmp = tmp->next;
1321                         break;
1322                 }
1323         }
1324         jffs2_free_xattr_ref(ref);
1325 }