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

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright © 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
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/fs.h>
  15 #include <linux/time.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/highmem.h>
  18 #include <linux/crc32.h>
  19 #include <linux/jffs2.h>
  20 #include <linux/xattr.h>
  21 #include <linux/mtd/mtd.h>
  22 #include "nodelist.h"
  23 /* -------- xdatum related functions ----------------
  24  * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  25  *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  26  *   the index of the xattr name/value pair cache (c->xattrindex).
  27  * is_xattr_datum_unchecked(c, xd)
  28  *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  29  *   unchecked, it returns 0.
  30  * unload_xattr_datum(c, xd)
  31  *   is used to release xattr name/value pair and detach from c->xattrindex.
  32  * reclaim_xattr_datum(c)
  33  *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  34  *   memory usage by cache is over c->xdatum_mem_threshold. Currentry, this threshold
  35  *   is hard coded as 32KiB.
  36  * do_verify_xattr_datum(c, xd)
  37  *   is used to load the xdatum informations without name/value pair from the medium.
  38  *   It's necessary once, because those informations are not collected during mounting
  39  *   process when EBS is enabled.
  40  *   0 will be returned, if success. An negative return value means recoverable error, and
  41  *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  42  *   and xref when it returned positive value.
  43  * do_load_xattr_datum(c, xd)
  44  *   is used to load name/value pair from the medium.
  45  *   The meanings of return value is same as do_verify_xattr_datum().
  46  * load_xattr_datum(c, xd)
  47  *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  48  *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  49  *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  50  * save_xattr_datum(c, xd)
  51  *   is used to write xdatum to medium. xd->version will be incremented.
  52  * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  53  *   is used to create new xdatum and write to medium.
  54  * unrefer_xattr_datum(c, xd)
  55  *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
  56  *   is set on xd->flags and chained xattr_dead_list or release it immediately.
  57  *   In the first case, the garbage collector release it later.
  58  * -------------------------------------------------- */
  59 static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
  60 {
  61         int name_len = strlen(xname);
  62
  63         return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
  64 }
  65
  66 static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  67 {
  68         struct jffs2_raw_node_ref *raw;
  69         int rc = 0;
  70
  71         spin_lock(&c->erase_completion_lock);
  72         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
  73                 if (ref_flags(raw) == REF_UNCHECKED) {
  74                         rc = 1;
  75                         break;
  76                 }
  77         }
  78         spin_unlock(&c->erase_completion_lock);
  79         return rc;
  80 }
  81
  82 static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  83 {
  84         /* must be called under down_write(xattr_sem) */
  85         D1(dbg_xattr("%s: xid=%u, version=%u\n", __FUNCTION__, xd->xid, xd->version));
  86         if (xd->xname) {
  87                 c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  88                 kfree(xd->xname);
  89         }
  90
  91         list_del_init(&xd->xindex);
  92         xd->hashkey = 0;
  93         xd->xname = NULL;
  94         xd->xvalue = NULL;
  95 }
  96
  97 static void reclaim_xattr_datum(struct jffs2_sb_info *c)
  98 {
  99         /* must be called under down_write(xattr_sem) */
 100         struct jffs2_xattr_datum *xd, *_xd;
 101         uint32_t target, before;
 102         static int index = 0;
 103         int count;
 104
 105         if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
 106                 return;
 107
 108         before = c->xdatum_mem_usage;
 109         target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
 110         for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
 111                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
 112                         if (xd->flags & JFFS2_XFLAGS_HOT) {
 113                                 xd->flags &= ~JFFS2_XFLAGS_HOT;
 114                         } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
 115                                 unload_xattr_datum(c, xd);
 116                         }
 117                         if (c->xdatum_mem_usage <= target)
 118                                 goto out;
 119                 }
 120                 index = (index+1) % XATTRINDEX_HASHSIZE;
 121         }
 122  out:
 123         JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 124                      before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 125 }
 126
 127 static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 128 {
 129         /* must be called under down_write(xattr_sem) */
 130         struct jffs2_eraseblock *jeb;
 131         struct jffs2_raw_node_ref *raw;
 132         struct jffs2_raw_xattr rx;
 133         size_t readlen;
 134         uint32_t crc, offset, totlen;
 135         int rc;
 136
 137         spin_lock(&c->erase_completion_lock);
 138         offset = ref_offset(xd->node);
 139         if (ref_flags(xd->node) == REF_PRISTINE)
 140                 goto complete;
 141         spin_unlock(&c->erase_completion_lock);
 142
 143         rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
 144         if (rc || readlen != sizeof(rx)) {
 145                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
 146                               rc, sizeof(rx), readlen, offset);
 147                 return rc ? rc : -EIO;
 148         }
 149         crc = crc32(0, &rx, sizeof(rx) - 4);
 150         if (crc != je32_to_cpu(rx.node_crc)) {
 151                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 152                             offset, je32_to_cpu(rx.hdr_crc), crc);
 153                 xd->flags |= JFFS2_XFLAGS_INVALID;
 154                 return EIO;
 155         }
 156         totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 157         if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 158             || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 159             || je32_to_cpu(rx.totlen) != totlen
 160             || je32_to_cpu(rx.xid) != xd->xid
 161             || je32_to_cpu(rx.version) != xd->version) {
 162                 JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 163                             "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 164                             offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
 165                             je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
 166                             je32_to_cpu(rx.totlen), totlen,
 167                             je32_to_cpu(rx.xid), xd->xid,
 168                             je32_to_cpu(rx.version), xd->version);
 169                 xd->flags |= JFFS2_XFLAGS_INVALID;
 170                 return EIO;
 171         }
 172         xd->xprefix = rx.xprefix;
 173         xd->name_len = rx.name_len;
 174         xd->value_len = je16_to_cpu(rx.value_len);
 175         xd->data_crc = je32_to_cpu(rx.data_crc);
 176
 177         spin_lock(&c->erase_completion_lock);
 178  complete:
 179         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
 180                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 181                 totlen = PAD(ref_totlen(c, jeb, raw));
 182                 if (ref_flags(raw) == REF_UNCHECKED) {
 183                         c->unchecked_size -= totlen; c->used_size += totlen;
 184                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 185                 }
 186                 raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
 187         }
 188         spin_unlock(&c->erase_completion_lock);
 189
 190         /* unchecked xdatum is chained with c->xattr_unchecked */
 191         list_del_init(&xd->xindex);
 192
 193         dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
 194                   xd->xid, xd->version);
 195
 196         return 0;
 197 }
 198
 199 static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 200 {
 201         /* must be called under down_write(xattr_sem) */
 202         char *data;
 203         size_t readlen;
 204         uint32_t crc, length;
 205         int i, ret, retry = 0;
 206
 207         BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 208         BUG_ON(!list_empty(&xd->xindex));
 209  retry:
 210         length = xd->name_len + 1 + xd->value_len;
 211         data = kmalloc(length, GFP_KERNEL);
 212         if (!data)
 213                 return -ENOMEM;
 214
 215         ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 216                                length, &readlen, data);
 217
 218         if (ret || length!=readlen) {
 219                 JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
 220                               ret, length, readlen, ref_offset(xd->node));
 221                 kfree(data);
 222                 return ret ? ret : -EIO;
 223         }
 224
 225         data[xd->name_len] = '\0';
 226         crc = crc32(0, data, length);
 227         if (crc != xd->data_crc) {
 228                 JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XREF)"
 229                               " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 230                               ref_offset(xd->node), xd->data_crc, crc);
 231                 kfree(data);
 232                 xd->flags |= JFFS2_XFLAGS_INVALID;
 233                 return EIO;
 234         }
 235
 236         xd->flags |= JFFS2_XFLAGS_HOT;
 237         xd->xname = data;
 238         xd->xvalue = data + xd->name_len+1;
 239
 240         c->xdatum_mem_usage += length;
 241
 242         xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 243         i = xd->hashkey % XATTRINDEX_HASHSIZE;
 244         list_add(&xd->xindex, &c->xattrindex[i]);
 245         if (!retry) {
 246                 retry = 1;
 247                 reclaim_xattr_datum(c);
 248                 if (!xd->xname)
 249                         goto retry;
 250         }
 251
 252         dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 253                   xd->xid, xd->xprefix, xd->xname);
 254
 255         return 0;
 256 }
 257
 258 static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 259 {
 260         /* must be called under down_write(xattr_sem);
 261          * rc < 0 : recoverable error, try again
 262          * rc = 0 : success
 263          * rc > 0 : Unrecoverable error, this node should be deleted.
 264          */
 265         int rc = 0;
 266
 267         BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
 268         if (xd->xname)
 269                 return 0;
 270         if (xd->flags & JFFS2_XFLAGS_INVALID)
 271                 return EIO;
 272         if (unlikely(is_xattr_datum_unchecked(c, xd)))
 273                 rc = do_verify_xattr_datum(c, xd);
 274         if (!rc)
 275                 rc = do_load_xattr_datum(c, xd);
 276         return rc;
 277 }
 278
 279 static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 280 {
 281         /* must be called under down_write(xattr_sem) */
 282         struct jffs2_raw_xattr rx;
 283         struct kvec vecs[2];
 284         size_t length;
 285         int rc, totlen;
 286         uint32_t phys_ofs = write_ofs(c);
 287
 288         BUG_ON(!xd->xname);
 289         BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
 290
 291         vecs[0].iov_base = &rx;
 292         vecs[0].iov_len = sizeof(rx);
 293         vecs[1].iov_base = xd->xname;
 294         vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 295         totlen = vecs[0].iov_len + vecs[1].iov_len;
 296
 297         /* Setup raw-xattr */
 298         memset(&rx, 0, sizeof(rx));
 299         rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 300         rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 301         rx.totlen = cpu_to_je32(PAD(totlen));
 302         rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 303
 304         rx.xid = cpu_to_je32(xd->xid);
 305         rx.version = cpu_to_je32(++xd->version);
 306         rx.xprefix = xd->xprefix;
 307         rx.name_len = xd->name_len;
 308         rx.value_len = cpu_to_je16(xd->value_len);
 309         rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 310         rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 311
 312         rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 313         if (rc || totlen != length) {
 314                 JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
 315                               rc, totlen, length, phys_ofs);
 316                 rc = rc ? rc : -EIO;
 317                 if (length)
 318                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
 319
 320                 return rc;
 321         }
 322         /* success */
 323         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
 324
 325         dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 326                   xd->xid, xd->version, xd->xprefix, xd->xname);
 327
 328         return 0;
 329 }
 330
 331 static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 332                                                     int xprefix, const char *xname,
 333                                                     const char *xvalue, int xsize)
 334 {
 335         /* must be called under down_write(xattr_sem) */
 336         struct jffs2_xattr_datum *xd;
 337         uint32_t hashkey, name_len;
 338         char *data;
 339         int i, rc;
 340
 341         /* Search xattr_datum has same xname/xvalue by index */
 342         hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 343         i = hashkey % XATTRINDEX_HASHSIZE;
 344         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 345                 if (xd->hashkey==hashkey
 346                     && xd->xprefix==xprefix
 347                     && xd->value_len==xsize
 348                     && !strcmp(xd->xname, xname)
 349                     && !memcmp(xd->xvalue, xvalue, xsize)) {
 350                         atomic_inc(&xd->refcnt);
 351                         return xd;
 352                 }
 353         }
 354
 355         /* Not found, Create NEW XATTR-Cache */
 356         name_len = strlen(xname);
 357
 358         xd = jffs2_alloc_xattr_datum();
 359         if (!xd)
 360                 return ERR_PTR(-ENOMEM);
 361
 362         data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 363         if (!data) {
 364                 jffs2_free_xattr_datum(xd);
 365                 return ERR_PTR(-ENOMEM);
 366         }
 367         strcpy(data, xname);
 368         memcpy(data + name_len + 1, xvalue, xsize);
 369
 370         atomic_set(&xd->refcnt, 1);
 371         xd->xid = ++c->highest_xid;
 372         xd->flags |= JFFS2_XFLAGS_HOT;
 373         xd->xprefix = xprefix;
 374
 375         xd->hashkey = hashkey;
 376         xd->xname = data;
 377         xd->xvalue = data + name_len + 1;
 378         xd->name_len = name_len;
 379         xd->value_len = xsize;
 380         xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 381
 382         rc = save_xattr_datum(c, xd);
 383         if (rc) {
 384                 kfree(xd->xname);
 385                 jffs2_free_xattr_datum(xd);
 386                 return ERR_PTR(rc);
 387         }
 388
 389         /* Insert Hash Index */
 390         i = hashkey % XATTRINDEX_HASHSIZE;
 391         list_add(&xd->xindex, &c->xattrindex[i]);
 392
 393         c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 394         reclaim_xattr_datum(c);
 395
 396         return xd;
 397 }
 398
 399 static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 400 {
 401         /* must be called under down_write(xattr_sem) */
 402         if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
 403                 unload_xattr_datum(c, xd);
 404                 xd->flags |= JFFS2_XFLAGS_DEAD;
 405                 if (xd->node == (void *)xd) {
 406                         BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 407                         jffs2_free_xattr_datum(xd);
 408                 } else {
 409                         list_add(&xd->xindex, &c->xattr_dead_list);
 410                 }
 411                 spin_unlock(&c->erase_completion_lock);
 412
 413                 dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
 414                           xd->xid, xd->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         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
 758                 list_del(&xd->xindex);
 759                 jffs2_free_xattr_datum(xd);
 760         }
 761 }
 762
 763 #define XREF_TMPHASH_SIZE       (128)
 764 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 765 {
 766         struct jffs2_xattr_ref *ref, *_ref;
 767         struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
 768         struct jffs2_xattr_datum *xd, *_xd;
 769         struct jffs2_inode_cache *ic;
 770         struct jffs2_raw_node_ref *raw;
 771         int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
 772         int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
 773
 774         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 775
 776         /* Phase.1 : Merge same xref */
 777         for (i=0; i < XREF_TMPHASH_SIZE; i++)
 778                 xref_tmphash[i] = NULL;
 779         for (ref=c->xref_temp; ref; ref=_ref) {
 780                 struct jffs2_xattr_ref *tmp;
 781
 782                 _ref = ref->next;
 783                 if (ref_flags(ref->node) != REF_PRISTINE) {
 784                         if (verify_xattr_ref(c, ref)) {
 785                                 BUG_ON(ref->node->next_in_ino != (void *)ref);
 786                                 ref->node->next_in_ino = NULL;
 787                                 jffs2_mark_node_obsolete(c, ref->node);
 788                                 jffs2_free_xattr_ref(ref);
 789                                 continue;
 790                         }
 791                 }
 792
 793                 i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
 794                 for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
 795                         if (tmp->ino == ref->ino && tmp->xid == ref->xid)
 796                                 break;
 797                 }
 798                 if (tmp) {
 799                         raw = ref->node;
 800                         if (ref->xseqno > tmp->xseqno) {
 801                                 tmp->xseqno = ref->xseqno;
 802                                 raw->next_in_ino = tmp->node;
 803                                 tmp->node = raw;
 804                         } else {
 805                                 raw->next_in_ino = tmp->node->next_in_ino;
 806                                 tmp->node->next_in_ino = raw;
 807                         }
 808                         jffs2_free_xattr_ref(ref);
 809                         continue;
 810                 } else {
 811                         ref->next = xref_tmphash[i];
 812                         xref_tmphash[i] = ref;
 813                 }
 814         }
 815         c->xref_temp = NULL;
 816
 817         /* Phase.2 : Bind xref with inode_cache and xattr_datum */
 818         for (i=0; i < XREF_TMPHASH_SIZE; i++) {
 819                 for (ref=xref_tmphash[i]; ref; ref=_ref) {
 820                         xref_count++;
 821                         _ref = ref->next;
 822                         if (is_xattr_ref_dead(ref)) {
 823                                 ref->next = c->xref_dead_list;
 824                                 c->xref_dead_list = ref;
 825                                 xref_dead_count++;
 826                                 continue;
 827                         }
 828                         /* At this point, ref->xid and ref->ino contain XID and inode number.
 829                            ref->xd and ref->ic are not valid yet. */
 830                         xd = jffs2_find_xattr_datum(c, ref->xid);
 831                         ic = jffs2_get_ino_cache(c, ref->ino);
 832                         if (!xd || !ic || !ic->nlink) {
 833                                 dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
 834                                           ref->ino, ref->xid, ref->xseqno);
 835                                 ref->xseqno |= XREF_DELETE_MARKER;
 836                                 ref->next = c->xref_dead_list;
 837                                 c->xref_dead_list = ref;
 838                                 xref_orphan_count++;
 839                                 continue;
 840                         }
 841                         ref->xd = xd;
 842                         ref->ic = ic;
 843                         atomic_inc(&xd->refcnt);
 844                         ref->next = ic->xref;
 845                         ic->xref = ref;
 846                 }
 847         }
 848
 849         /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
 850         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 851                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 852                         xdatum_count++;
 853                         list_del_init(&xd->xindex);
 854                         if (!atomic_read(&xd->refcnt)) {
 855                                 dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
 856                                           xd->xid, xd->version);
 857                                 xd->flags |= JFFS2_XFLAGS_DEAD;
 858                                 list_add(&xd->xindex, &c->xattr_unchecked);
 859                                 xdatum_orphan_count++;
 860                                 continue;
 861                         }
 862                         if (is_xattr_datum_unchecked(c, xd)) {
 863                                 dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
 864                                           xd->xid, xd->version);
 865                                 list_add(&xd->xindex, &c->xattr_unchecked);
 866                                 xdatum_unchecked_count++;
 867                         }
 868                 }
 869         }
 870         /* build complete */
 871         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
 872                      " (%u unchecked, %u orphan) and "
 873                      "%u of xref (%u dead, %u orphan) found.\n",
 874                      xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
 875                      xref_count, xref_dead_count, xref_orphan_count);
 876 }
 877
 878 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 879                                                   uint32_t xid, uint32_t version)
 880 {
 881         struct jffs2_xattr_datum *xd;
 882
 883         xd = jffs2_find_xattr_datum(c, xid);
 884         if (!xd) {
 885                 xd = jffs2_alloc_xattr_datum();
 886                 if (!xd)
 887                         return ERR_PTR(-ENOMEM);
 888                 xd->xid = xid;
 889                 xd->version = version;
 890                 if (xd->xid > c->highest_xid)
 891                         c->highest_xid = xd->xid;
 892                 list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 893         }
 894         return xd;
 895 }
 896
 897 /* -------- xattr subsystem functions ---------------
 898  * xprefix_to_handler(xprefix)
 899  *   is used to translate xprefix into xattr_handler.
 900  * jffs2_listxattr(dentry, buffer, size)
 901  *   is an implementation of listxattr handler on jffs2.
 902  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 903  *   is an implementation of getxattr handler on jffs2.
 904  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 905  *   is an implementation of setxattr handler on jffs2.
 906  * -------------------------------------------------- */
 907 struct xattr_handler *jffs2_xattr_handlers[] = {
 908         &jffs2_user_xattr_handler,
 909 #ifdef CONFIG_JFFS2_FS_SECURITY
 910         &jffs2_security_xattr_handler,
 911 #endif
 912 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 913         &jffs2_acl_access_xattr_handler,
 914         &jffs2_acl_default_xattr_handler,
 915 #endif
 916         &jffs2_trusted_xattr_handler,
 917         NULL
 918 };
 919
 920 static struct xattr_handler *xprefix_to_handler(int xprefix) {
 921         struct xattr_handler *ret;
 922
 923         switch (xprefix) {
 924         case JFFS2_XPREFIX_USER:
 925                 ret = &jffs2_user_xattr_handler;
 926                 break;
 927 #ifdef CONFIG_JFFS2_FS_SECURITY
 928         case JFFS2_XPREFIX_SECURITY:
 929                 ret = &jffs2_security_xattr_handler;
 930                 break;
 931 #endif
 932 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 933         case JFFS2_XPREFIX_ACL_ACCESS:
 934                 ret = &jffs2_acl_access_xattr_handler;
 935                 break;
 936         case JFFS2_XPREFIX_ACL_DEFAULT:
 937                 ret = &jffs2_acl_default_xattr_handler;
 938                 break;
 939 #endif
 940         case JFFS2_XPREFIX_TRUSTED:
 941                 ret = &jffs2_trusted_xattr_handler;
 942                 break;
 943         default:
 944                 ret = NULL;
 945                 break;
 946         }
 947         return ret;
 948 }
 949
 950 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 951 {
 952         struct inode *inode = dentry->d_inode;
 953         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 954         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 955         struct jffs2_inode_cache *ic = f->inocache;
 956         struct jffs2_xattr_ref *ref, **pref;
 957         struct jffs2_xattr_datum *xd;
 958         struct xattr_handler *xhandle;
 959         ssize_t len, rc;
 960         int retry = 0;
 961
 962         rc = check_xattr_ref_inode(c, ic);
 963         if (unlikely(rc))
 964                 return rc;
 965
 966         down_read(&c->xattr_sem);
 967  retry:
 968         len = 0;
 969         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 970                 BUG_ON(ref->ic != ic);
 971                 xd = ref->xd;
 972                 if (!xd->xname) {
 973                         /* xdatum is unchached */
 974                         if (!retry) {
 975                                 retry = 1;
 976                                 up_read(&c->xattr_sem);
 977                                 down_write(&c->xattr_sem);
 978                                 goto retry;
 979                         } else {
 980                                 rc = load_xattr_datum(c, xd);
 981                                 if (unlikely(rc > 0)) {
 982                                         *pref = ref->next;
 983                                         delete_xattr_ref(c, ref);
 984                                         goto retry;
 985                                 } else if (unlikely(rc < 0))
 986                                         goto out;
 987                         }
 988                 }
 989                 xhandle = xprefix_to_handler(xd->xprefix);
 990                 if (!xhandle)
 991                         continue;
 992                 if (buffer) {
 993                         rc = xhandle->list(inode, buffer+len, size-len, xd->xname, xd->name_len);
 994                 } else {
 995                         rc = xhandle->list(inode, NULL, 0, xd->xname, xd->name_len);
 996                 }
 997                 if (rc < 0)
 998                         goto out;
 999                 len += rc;
1000         }
1001         rc = len;
1002  out:
1003         if (!retry) {
1004                 up_read(&c->xattr_sem);
1005         } else {
1006                 up_write(&c->xattr_sem);
1007         }
1008         return rc;
1009 }
1010
1011 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1012                       char *buffer, size_t size)
1013 {
1014         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1015         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1016         struct jffs2_inode_cache *ic = f->inocache;
1017         struct jffs2_xattr_datum *xd;
1018         struct jffs2_xattr_ref *ref, **pref;
1019         int rc, retry = 0;
1020
1021         rc = check_xattr_ref_inode(c, ic);
1022         if (unlikely(rc))
1023                 return rc;
1024
1025         down_read(&c->xattr_sem);
1026  retry:
1027         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1028                 BUG_ON(ref->ic!=ic);
1029
1030                 xd = ref->xd;
1031                 if (xd->xprefix != xprefix)
1032                         continue;
1033                 if (!xd->xname) {
1034                         /* xdatum is unchached */
1035                         if (!retry) {
1036                                 retry = 1;
1037                                 up_read(&c->xattr_sem);
1038                                 down_write(&c->xattr_sem);
1039                                 goto retry;
1040                         } else {
1041                                 rc = load_xattr_datum(c, xd);
1042                                 if (unlikely(rc > 0)) {
1043                                         *pref = ref->next;
1044                                         delete_xattr_ref(c, ref);
1045                                         goto retry;
1046                                 } else if (unlikely(rc < 0)) {
1047                                         goto out;
1048                                 }
1049                         }
1050                 }
1051                 if (!strcmp(xname, xd->xname)) {
1052                         rc = xd->value_len;
1053                         if (buffer) {
1054                                 if (size < rc) {
1055                                         rc = -ERANGE;
1056                                 } else {
1057                                         memcpy(buffer, xd->xvalue, rc);
1058                                 }
1059                         }
1060                         goto out;
1061                 }
1062         }
1063         rc = -ENODATA;
1064  out:
1065         if (!retry) {
1066                 up_read(&c->xattr_sem);
1067         } else {
1068                 up_write(&c->xattr_sem);
1069         }
1070         return rc;
1071 }
1072
1073 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1074                       const char *buffer, size_t size, int flags)
1075 {
1076         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1077         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1078         struct jffs2_inode_cache *ic = f->inocache;
1079         struct jffs2_xattr_datum *xd;
1080         struct jffs2_xattr_ref *ref, *newref, **pref;
1081         uint32_t length, request;
1082         int rc;
1083
1084         rc = check_xattr_ref_inode(c, ic);
1085         if (unlikely(rc))
1086                 return rc;
1087
1088         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1089         rc = jffs2_reserve_space(c, request, &length,
1090                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1091         if (rc) {
1092                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1093                 return rc;
1094         }
1095
1096         /* Find existing xattr */
1097         down_write(&c->xattr_sem);
1098  retry:
1099         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1100                 xd = ref->xd;
1101                 if (xd->xprefix != xprefix)
1102                         continue;
1103                 if (!xd->xname) {
1104                         rc = load_xattr_datum(c, xd);
1105                         if (unlikely(rc > 0)) {
1106                                 *pref = ref->next;
1107                                 delete_xattr_ref(c, ref);
1108                                 goto retry;
1109                         } else if (unlikely(rc < 0))
1110                                 goto out;
1111                 }
1112                 if (!strcmp(xd->xname, xname)) {
1113                         if (flags & XATTR_CREATE) {
1114                                 rc = -EEXIST;
1115                                 goto out;
1116                         }
1117                         if (!buffer) {
1118                                 ref->ino = ic->ino;
1119                                 ref->xid = xd->xid;
1120                                 ref->xseqno |= XREF_DELETE_MARKER;
1121                                 rc = save_xattr_ref(c, ref);
1122                                 if (!rc) {
1123                                         *pref = ref->next;
1124                                         spin_lock(&c->erase_completion_lock);
1125                                         ref->next = c->xref_dead_list;
1126                                         c->xref_dead_list = ref;
1127                                         spin_unlock(&c->erase_completion_lock);
1128                                         unrefer_xattr_datum(c, xd);
1129                                 } else {
1130                                         ref->ic = ic;
1131                                         ref->xd = xd;
1132                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1133                                 }
1134                                 goto out;
1135                         }
1136                         goto found;
1137                 }
1138         }
1139         /* not found */
1140         if (flags & XATTR_REPLACE) {
1141                 rc = -ENODATA;
1142                 goto out;
1143         }
1144         if (!buffer) {
1145                 rc = -ENODATA;
1146                 goto out;
1147         }
1148  found:
1149         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1150         if (IS_ERR(xd)) {
1151                 rc = PTR_ERR(xd);
1152                 goto out;
1153         }
1154         up_write(&c->xattr_sem);
1155         jffs2_complete_reservation(c);
1156
1157         /* create xattr_ref */
1158         request = PAD(sizeof(struct jffs2_raw_xref));
1159         rc = jffs2_reserve_space(c, request, &length,
1160                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1161         down_write(&c->xattr_sem);
1162         if (rc) {
1163                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1164                 unrefer_xattr_datum(c, xd);
1165                 up_write(&c->xattr_sem);
1166                 return rc;
1167         }
1168         if (ref)
1169                 *pref = ref->next;
1170         newref = create_xattr_ref(c, ic, xd);
1171         if (IS_ERR(newref)) {
1172                 if (ref) {
1173                         ref->next = ic->xref;
1174                         ic->xref = ref;
1175                 }
1176                 rc = PTR_ERR(newref);
1177                 unrefer_xattr_datum(c, xd);
1178         } else if (ref) {
1179                 delete_xattr_ref(c, ref);
1180         }
1181  out:
1182         up_write(&c->xattr_sem);
1183         jffs2_complete_reservation(c);
1184         return rc;
1185 }
1186
1187 /* -------- garbage collector functions -------------
1188  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1189  *   is used to move xdatum into new node.
1190  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1191  *   is used to move xref into new node.
1192  * jffs2_verify_xattr(c)
1193  *   is used to call do_verify_xattr_datum() before garbage collecting.
1194  * jffs2_release_xattr_datum(c, xd)
1195  *   is used to release an in-memory object of xdatum.
1196  * jffs2_release_xattr_ref(c, ref)
1197  *   is used to release an in-memory object of xref.
1198  * -------------------------------------------------- */
1199 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1200                                       struct jffs2_raw_node_ref *raw)
1201 {
1202         uint32_t totlen, length, old_ofs;
1203         int rc = 0;
1204
1205         down_write(&c->xattr_sem);
1206         if (xd->node != raw)
1207                 goto out;
1208         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1209                 goto out;
1210
1211         rc = load_xattr_datum(c, xd);
1212         if (unlikely(rc)) {
1213                 rc = (rc > 0) ? 0 : rc;
1214                 goto out;
1215         }
1216         old_ofs = ref_offset(xd->node);
1217         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1218                         + xd->name_len + 1 + xd->value_len);
1219         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1220         if (rc) {
1221                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1222                 goto out;
1223         }
1224         rc = save_xattr_datum(c, xd);
1225         if (!rc)
1226                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1227                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1228  out:
1229         if (!rc)
1230                 jffs2_mark_node_obsolete(c, raw);
1231         up_write(&c->xattr_sem);
1232         return rc;
1233 }
1234
1235 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1236                                     struct jffs2_raw_node_ref *raw)
1237 {
1238         uint32_t totlen, length, old_ofs;
1239         int rc = 0;
1240
1241         down_write(&c->xattr_sem);
1242         BUG_ON(!ref->node);
1243
1244         if (ref->node != raw)
1245                 goto out;
1246         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1247                 goto out;
1248
1249         old_ofs = ref_offset(ref->node);
1250         totlen = ref_totlen(c, c->gcblock, ref->node);
1251
1252         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1253         if (rc) {
1254                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1255                               __FUNCTION__, rc, totlen);
1256                 rc = rc ? rc : -EBADFD;
1257                 goto out;
1258         }
1259         rc = save_xattr_ref(c, ref);
1260         if (!rc)
1261                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1262                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1263  out:
1264         if (!rc)
1265                 jffs2_mark_node_obsolete(c, raw);
1266         up_write(&c->xattr_sem);
1267         return rc;
1268 }
1269
1270 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1271 {
1272         struct jffs2_xattr_datum *xd, *_xd;
1273         struct jffs2_eraseblock *jeb;
1274         struct jffs2_raw_node_ref *raw;
1275         uint32_t totlen;
1276         int rc;
1277
1278         down_write(&c->xattr_sem);
1279         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1280                 rc = do_verify_xattr_datum(c, xd);
1281                 if (rc < 0)
1282                         continue;
1283                 list_del_init(&xd->xindex);
1284                 spin_lock(&c->erase_completion_lock);
1285                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1286                         if (ref_flags(raw) != REF_UNCHECKED)
1287                                 continue;
1288                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1289                         totlen = PAD(ref_totlen(c, jeb, raw));
1290                         c->unchecked_size -= totlen; c->used_size += totlen;
1291                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1292                         raw->flash_offset = ref_offset(raw)
1293                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1294                 }
1295                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1296                         list_add(&xd->xindex, &c->xattr_dead_list);
1297                 spin_unlock(&c->erase_completion_lock);
1298         }
1299         up_write(&c->xattr_sem);
1300         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1301 }
1302
1303 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1304 {
1305         /* must be called under spin_lock(&c->erase_completion_lock) */
1306         if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1307                 return;
1308
1309         list_del(&xd->xindex);
1310         jffs2_free_xattr_datum(xd);
1311 }
1312
1313 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1314 {
1315         /* must be called under spin_lock(&c->erase_completion_lock) */
1316         struct jffs2_xattr_ref *tmp, **ptmp;
1317
1318         if (ref->node != (void *)ref)
1319                 return;
1320
1321         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1322                 if (ref == tmp) {
1323                         *ptmp = tmp->next;
1324                         break;
1325                 }
1326         }
1327         jffs2_free_xattr_ref(ref);
1328 }