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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #define JFFS2_XATTR_IS_CORRUPTED        1
  15
  16 #include <linux/kernel.h>
  17 #include <linux/slab.h>
  18 #include <linux/fs.h>
  19 #include <linux/time.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/highmem.h>
  22 #include <linux/crc32.h>
  23 #include <linux/jffs2.h>
  24 #include <linux/xattr.h>
  25 #include <linux/mtd/mtd.h>
  26 #include "nodelist.h"
  27 /* -------- xdatum related functions ----------------
  28  * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  29  *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  30  *   the index of the xattr name/value pair cache (c->xattrindex).
  31  * is_xattr_datum_unchecked(c, xd)
  32  *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  33  *   unchecked, it returns 0.
  34  * unload_xattr_datum(c, xd)
  35  *   is used to release xattr name/value pair and detach from c->xattrindex.
  36  * reclaim_xattr_datum(c)
  37  *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  38  *   memory usage by cache is over c->xdatum_mem_threshold. Currently, this threshold
  39  *   is hard coded as 32KiB.
  40  * do_verify_xattr_datum(c, xd)
  41  *   is used to load the xdatum informations without name/value pair from the medium.
  42  *   It's necessary once, because those informations are not collected during mounting
  43  *   process when EBS is enabled.
  44  *   0 will be returned, if success. An negative return value means recoverable error, and
  45  *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  46  *   and xref when it returned positive value.
  47  * do_load_xattr_datum(c, xd)
  48  *   is used to load name/value pair from the medium.
  49  *   The meanings of return value is same as do_verify_xattr_datum().
  50  * load_xattr_datum(c, xd)
  51  *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  52  *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  53  *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  54  * save_xattr_datum(c, xd)
  55  *   is used to write xdatum to medium. xd->version will be incremented.
  56  * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  57  *   is used to create new xdatum and write to medium.
  58  * unrefer_xattr_datum(c, xd)
  59  *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
  60  *   is set on xd->flags and chained xattr_dead_list or release it immediately.
  61  *   In the first case, the garbage collector release it later.
  62  * -------------------------------------------------- */
  63 static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
  64 {
  65         int name_len = strlen(xname);
  66
  67         return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
  68 }
  69
  70 static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  71 {
  72         struct jffs2_raw_node_ref *raw;
  73         int rc = 0;
  74
  75         spin_lock(&c->erase_completion_lock);
  76         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
  77                 if (ref_flags(raw) == REF_UNCHECKED) {
  78                         rc = 1;
  79                         break;
  80                 }
  81         }
  82         spin_unlock(&c->erase_completion_lock);
  83         return rc;
  84 }
  85
  86 static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  87 {
  88         /* must be called under down_write(xattr_sem) */
  89         D1(dbg_xattr("%s: xid=%u, version=%u\n", __func__, xd->xid, xd->version));
  90         if (xd->xname) {
  91                 c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  92                 kfree(xd->xname);
  93         }
  94
  95         list_del_init(&xd->xindex);
  96         xd->hashkey = 0;
  97         xd->xname = NULL;
  98         xd->xvalue = NULL;
  99 }
 100
 101 static void reclaim_xattr_datum(struct jffs2_sb_info *c)
 102 {
 103         /* must be called under down_write(xattr_sem) */
 104         struct jffs2_xattr_datum *xd, *_xd;
 105         uint32_t target, before;
 106         static int index = 0;
 107         int count;
 108
 109         if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
 110                 return;
 111
 112         before = c->xdatum_mem_usage;
 113         target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
 114         for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
 115                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
 116                         if (xd->flags & JFFS2_XFLAGS_HOT) {
 117                                 xd->flags &= ~JFFS2_XFLAGS_HOT;
 118                         } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
 119                                 unload_xattr_datum(c, xd);
 120                         }
 121                         if (c->xdatum_mem_usage <= target)
 122                                 goto out;
 123                 }
 124                 index = (index+1) % XATTRINDEX_HASHSIZE;
 125         }
 126  out:
 127         JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 128                      before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 129 }
 130
 131 static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 132 {
 133         /* must be called under down_write(xattr_sem) */
 134         struct jffs2_eraseblock *jeb;
 135         struct jffs2_raw_node_ref *raw;
 136         struct jffs2_raw_xattr rx;
 137         size_t readlen;
 138         uint32_t crc, offset, totlen;
 139         int rc;
 140
 141         spin_lock(&c->erase_completion_lock);
 142         offset = ref_offset(xd->node);
 143         if (ref_flags(xd->node) == REF_PRISTINE)
 144                 goto complete;
 145         spin_unlock(&c->erase_completion_lock);
 146
 147         rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
 148         if (rc || readlen != sizeof(rx)) {
 149                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
 150                               rc, sizeof(rx), readlen, offset);
 151                 return rc ? rc : -EIO;
 152         }
 153         crc = crc32(0, &rx, sizeof(rx) - 4);
 154         if (crc != je32_to_cpu(rx.node_crc)) {
 155                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 156                             offset, je32_to_cpu(rx.hdr_crc), crc);
 157                 xd->flags |= JFFS2_XFLAGS_INVALID;
 158                 return JFFS2_XATTR_IS_CORRUPTED;
 159         }
 160         totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 161         if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 162             || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 163             || je32_to_cpu(rx.totlen) != totlen
 164             || je32_to_cpu(rx.xid) != xd->xid
 165             || je32_to_cpu(rx.version) != xd->version) {
 166                 JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 167                             "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 168                             offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
 169                             je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
 170                             je32_to_cpu(rx.totlen), totlen,
 171                             je32_to_cpu(rx.xid), xd->xid,
 172                             je32_to_cpu(rx.version), xd->version);
 173                 xd->flags |= JFFS2_XFLAGS_INVALID;
 174                 return JFFS2_XATTR_IS_CORRUPTED;
 175         }
 176         xd->xprefix = rx.xprefix;
 177         xd->name_len = rx.name_len;
 178         xd->value_len = je16_to_cpu(rx.value_len);
 179         xd->data_crc = je32_to_cpu(rx.data_crc);
 180
 181         spin_lock(&c->erase_completion_lock);
 182  complete:
 183         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
 184                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 185                 totlen = PAD(ref_totlen(c, jeb, raw));
 186                 if (ref_flags(raw) == REF_UNCHECKED) {
 187                         c->unchecked_size -= totlen; c->used_size += totlen;
 188                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 189                 }
 190                 raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
 191         }
 192         spin_unlock(&c->erase_completion_lock);
 193
 194         /* unchecked xdatum is chained with c->xattr_unchecked */
 195         list_del_init(&xd->xindex);
 196
 197         dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
 198                   xd->xid, xd->version);
 199
 200         return 0;
 201 }
 202
 203 static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 204 {
 205         /* must be called under down_write(xattr_sem) */
 206         char *data;
 207         size_t readlen;
 208         uint32_t crc, length;
 209         int i, ret, retry = 0;
 210
 211         BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 212         BUG_ON(!list_empty(&xd->xindex));
 213  retry:
 214         length = xd->name_len + 1 + xd->value_len;
 215         data = kmalloc(length, GFP_KERNEL);
 216         if (!data)
 217                 return -ENOMEM;
 218
 219         ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 220                                length, &readlen, data);
 221
 222         if (ret || length!=readlen) {
 223                 JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
 224                               ret, length, readlen, ref_offset(xd->node));
 225                 kfree(data);
 226                 return ret ? ret : -EIO;
 227         }
 228
 229         data[xd->name_len] = '\0';
 230         crc = crc32(0, data, length);
 231         if (crc != xd->data_crc) {
 232                 JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XATTR)"
 233                               " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 234                               ref_offset(xd->node), xd->data_crc, crc);
 235                 kfree(data);
 236                 xd->flags |= JFFS2_XFLAGS_INVALID;
 237                 return JFFS2_XATTR_IS_CORRUPTED;
 238         }
 239
 240         xd->flags |= JFFS2_XFLAGS_HOT;
 241         xd->xname = data;
 242         xd->xvalue = data + xd->name_len+1;
 243
 244         c->xdatum_mem_usage += length;
 245
 246         xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 247         i = xd->hashkey % XATTRINDEX_HASHSIZE;
 248         list_add(&xd->xindex, &c->xattrindex[i]);
 249         if (!retry) {
 250                 retry = 1;
 251                 reclaim_xattr_datum(c);
 252                 if (!xd->xname)
 253                         goto retry;
 254         }
 255
 256         dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 257                   xd->xid, xd->xprefix, xd->xname);
 258
 259         return 0;
 260 }
 261
 262 static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 263 {
 264         /* must be called under down_write(xattr_sem);
 265          * rc < 0 : recoverable error, try again
 266          * rc = 0 : success
 267          * rc > 0 : Unrecoverable error, this node should be deleted.
 268          */
 269         int rc = 0;
 270
 271         BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
 272         if (xd->xname)
 273                 return 0;
 274         if (xd->flags & JFFS2_XFLAGS_INVALID)
 275                 return JFFS2_XATTR_IS_CORRUPTED;
 276         if (unlikely(is_xattr_datum_unchecked(c, xd)))
 277                 rc = do_verify_xattr_datum(c, xd);
 278         if (!rc)
 279                 rc = do_load_xattr_datum(c, xd);
 280         return rc;
 281 }
 282
 283 static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 284 {
 285         /* must be called under down_write(xattr_sem) */
 286         struct jffs2_raw_xattr rx;
 287         struct kvec vecs[2];
 288         size_t length;
 289         int rc, totlen;
 290         uint32_t phys_ofs = write_ofs(c);
 291
 292         BUG_ON(!xd->xname);
 293         BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
 294
 295         vecs[0].iov_base = &rx;
 296         vecs[0].iov_len = sizeof(rx);
 297         vecs[1].iov_base = xd->xname;
 298         vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 299         totlen = vecs[0].iov_len + vecs[1].iov_len;
 300
 301         /* Setup raw-xattr */
 302         memset(&rx, 0, sizeof(rx));
 303         rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 304         rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 305         rx.totlen = cpu_to_je32(PAD(totlen));
 306         rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 307
 308         rx.xid = cpu_to_je32(xd->xid);
 309         rx.version = cpu_to_je32(++xd->version);
 310         rx.xprefix = xd->xprefix;
 311         rx.name_len = xd->name_len;
 312         rx.value_len = cpu_to_je16(xd->value_len);
 313         rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 314         rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 315
 316         rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 317         if (rc || totlen != length) {
 318                 JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
 319                               rc, totlen, length, phys_ofs);
 320                 rc = rc ? rc : -EIO;
 321                 if (length)
 322                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
 323
 324                 return rc;
 325         }
 326         /* success */
 327         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
 328
 329         dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 330                   xd->xid, xd->version, xd->xprefix, xd->xname);
 331
 332         return 0;
 333 }
 334
 335 static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 336                                                     int xprefix, const char *xname,
 337                                                     const char *xvalue, int xsize)
 338 {
 339         /* must be called under down_write(xattr_sem) */
 340         struct jffs2_xattr_datum *xd;
 341         uint32_t hashkey, name_len;
 342         char *data;
 343         int i, rc;
 344
 345         /* Search xattr_datum has same xname/xvalue by index */
 346         hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 347         i = hashkey % XATTRINDEX_HASHSIZE;
 348         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 349                 if (xd->hashkey==hashkey
 350                     && xd->xprefix==xprefix
 351                     && xd->value_len==xsize
 352                     && !strcmp(xd->xname, xname)
 353                     && !memcmp(xd->xvalue, xvalue, xsize)) {
 354                         atomic_inc(&xd->refcnt);
 355                         return xd;
 356                 }
 357         }
 358
 359         /* Not found, Create NEW XATTR-Cache */
 360         name_len = strlen(xname);
 361
 362         xd = jffs2_alloc_xattr_datum();
 363         if (!xd)
 364                 return ERR_PTR(-ENOMEM);
 365
 366         data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 367         if (!data) {
 368                 jffs2_free_xattr_datum(xd);
 369                 return ERR_PTR(-ENOMEM);
 370         }
 371         strcpy(data, xname);
 372         memcpy(data + name_len + 1, xvalue, xsize);
 373
 374         atomic_set(&xd->refcnt, 1);
 375         xd->xid = ++c->highest_xid;
 376         xd->flags |= JFFS2_XFLAGS_HOT;
 377         xd->xprefix = xprefix;
 378
 379         xd->hashkey = hashkey;
 380         xd->xname = data;
 381         xd->xvalue = data + name_len + 1;
 382         xd->name_len = name_len;
 383         xd->value_len = xsize;
 384         xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 385
 386         rc = save_xattr_datum(c, xd);
 387         if (rc) {
 388                 kfree(xd->xname);
 389                 jffs2_free_xattr_datum(xd);
 390                 return ERR_PTR(rc);
 391         }
 392
 393         /* Insert Hash Index */
 394         i = hashkey % XATTRINDEX_HASHSIZE;
 395         list_add(&xd->xindex, &c->xattrindex[i]);
 396
 397         c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 398         reclaim_xattr_datum(c);
 399
 400         return xd;
 401 }
 402
 403 static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 404 {
 405         /* must be called under down_write(xattr_sem) */
 406         if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
 407                 unload_xattr_datum(c, xd);
 408                 xd->flags |= JFFS2_XFLAGS_DEAD;
 409                 if (xd->node == (void *)xd) {
 410                         BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 411                         jffs2_free_xattr_datum(xd);
 412                 } else {
 413                         list_add(&xd->xindex, &c->xattr_dead_list);
 414                 }
 415                 spin_unlock(&c->erase_completion_lock);
 416
 417                 dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
 418                           xd->xid, xd->version);
 419         }
 420 }
 421
 422 /* -------- xref related functions ------------------
 423  * verify_xattr_ref(c, ref)
 424  *   is used to load xref information from medium. Because summary data does not
 425  *   contain xid/ino, it's necessary to verify once while mounting process.
 426  * save_xattr_ref(c, ref)
 427  *   is used to write xref to medium. If delete marker is marked, it write
 428  *   a delete marker of xref into medium.
 429  * create_xattr_ref(c, ic, xd)
 430  *   is used to create a new xref and write to medium.
 431  * delete_xattr_ref(c, ref)
 432  *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 433  *   and allows GC to reclaim those physical nodes.
 434  * jffs2_xattr_delete_inode(c, ic)
 435  *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 436  * jffs2_xattr_free_inode(c, ic)
 437  *   is called to release xattr related objects when unmounting.
 438  * check_xattr_ref_inode(c, ic)
 439  *   is used to confirm inode does not have duplicate xattr name/value pair.
 440  * jffs2_xattr_do_crccheck_inode(c, ic)
 441  *   is used to force xattr data integrity check during the initial gc scan.
 442  * -------------------------------------------------- */
 443 static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 444 {
 445         struct jffs2_eraseblock *jeb;
 446         struct jffs2_raw_node_ref *raw;
 447         struct jffs2_raw_xref rr;
 448         size_t readlen;
 449         uint32_t crc, offset, totlen;
 450         int rc;
 451
 452         spin_lock(&c->erase_completion_lock);
 453         if (ref_flags(ref->node) != REF_UNCHECKED)
 454                 goto complete;
 455         offset = ref_offset(ref->node);
 456         spin_unlock(&c->erase_completion_lock);
 457
 458         rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
 459         if (rc || sizeof(rr) != readlen) {
 460                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
 461                               rc, sizeof(rr), readlen, offset);
 462                 return rc ? rc : -EIO;
 463         }
 464         /* obsolete node */
 465         crc = crc32(0, &rr, sizeof(rr) - 4);
 466         if (crc != je32_to_cpu(rr.node_crc)) {
 467                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 468                             offset, je32_to_cpu(rr.node_crc), crc);
 469                 return JFFS2_XATTR_IS_CORRUPTED;
 470         }
 471         if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 472             || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 473             || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 474                 JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 475                             "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
 476                             offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 477                             je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 478                             je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 479                 return JFFS2_XATTR_IS_CORRUPTED;
 480         }
 481         ref->ino = je32_to_cpu(rr.ino);
 482         ref->xid = je32_to_cpu(rr.xid);
 483         ref->xseqno = je32_to_cpu(rr.xseqno);
 484         if (ref->xseqno > c->highest_xseqno)
 485                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 486
 487         spin_lock(&c->erase_completion_lock);
 488  complete:
 489         for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
 490                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 491                 totlen = PAD(ref_totlen(c, jeb, raw));
 492                 if (ref_flags(raw) == REF_UNCHECKED) {
 493                         c->unchecked_size -= totlen; c->used_size += totlen;
 494                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 495                 }
 496                 raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
 497         }
 498         spin_unlock(&c->erase_completion_lock);
 499
 500         dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 501                   ref->ino, ref->xid, ref_offset(ref->node));
 502         return 0;
 503 }
 504
 505 static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 506 {
 507         /* must be called under down_write(xattr_sem) */
 508         struct jffs2_raw_xref rr;
 509         size_t length;
 510         uint32_t xseqno, phys_ofs = write_ofs(c);
 511         int ret;
 512
 513         rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 514         rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 515         rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 516         rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 517
 518         xseqno = (c->highest_xseqno += 2);
 519         if (is_xattr_ref_dead(ref)) {
 520                 xseqno |= XREF_DELETE_MARKER;
 521                 rr.ino = cpu_to_je32(ref->ino);
 522                 rr.xid = cpu_to_je32(ref->xid);
 523         } else {
 524                 rr.ino = cpu_to_je32(ref->ic->ino);
 525                 rr.xid = cpu_to_je32(ref->xd->xid);
 526         }
 527         rr.xseqno = cpu_to_je32(xseqno);
 528         rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 529
 530         ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 531         if (ret || sizeof(rr) != length) {
 532                 JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
 533                               ret, sizeof(rr), length, phys_ofs);
 534                 ret = ret ? ret : -EIO;
 535                 if (length)
 536                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
 537
 538                 return ret;
 539         }
 540         /* success */
 541         ref->xseqno = xseqno;
 542         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
 543
 544         dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 545
 546         return 0;
 547 }
 548
 549 static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 550                                                 struct jffs2_xattr_datum *xd)
 551 {
 552         /* must be called under down_write(xattr_sem) */
 553         struct jffs2_xattr_ref *ref;
 554         int ret;
 555
 556         ref = jffs2_alloc_xattr_ref();
 557         if (!ref)
 558                 return ERR_PTR(-ENOMEM);
 559         ref->ic = ic;
 560         ref->xd = xd;
 561
 562         ret = save_xattr_ref(c, ref);
 563         if (ret) {
 564                 jffs2_free_xattr_ref(ref);
 565                 return ERR_PTR(ret);
 566         }
 567
 568         /* Chain to inode */
 569         ref->next = ic->xref;
 570         ic->xref = ref;
 571
 572         return ref; /* success */
 573 }
 574
 575 static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 576 {
 577         /* must be called under down_write(xattr_sem) */
 578         struct jffs2_xattr_datum *xd;
 579
 580         xd = ref->xd;
 581         ref->xseqno |= XREF_DELETE_MARKER;
 582         ref->ino = ref->ic->ino;
 583         ref->xid = ref->xd->xid;
 584         spin_lock(&c->erase_completion_lock);
 585         ref->next = c->xref_dead_list;
 586         c->xref_dead_list = ref;
 587         spin_unlock(&c->erase_completion_lock);
 588
 589         dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
 590                   ref->ino, ref->xid, ref->xseqno);
 591
 592         unrefer_xattr_datum(c, xd);
 593 }
 594
 595 void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 596 {
 597         /* It's called from jffs2_evict_inode() on inode removing.
 598            When an inode with XATTR is removed, those XATTRs must be removed. */
 599         struct jffs2_xattr_ref *ref, *_ref;
 600
 601         if (!ic || ic->pino_nlink > 0)
 602                 return;
 603
 604         down_write(&c->xattr_sem);
 605         for (ref = ic->xref; ref; ref = _ref) {
 606                 _ref = ref->next;
 607                 delete_xattr_ref(c, ref);
 608         }
 609         ic->xref = NULL;
 610         up_write(&c->xattr_sem);
 611 }
 612
 613 void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 614 {
 615         /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 616         struct jffs2_xattr_datum *xd;
 617         struct jffs2_xattr_ref *ref, *_ref;
 618
 619         down_write(&c->xattr_sem);
 620         for (ref = ic->xref; ref; ref = _ref) {
 621                 _ref = ref->next;
 622                 xd = ref->xd;
 623                 if (atomic_dec_and_test(&xd->refcnt)) {
 624                         unload_xattr_datum(c, xd);
 625                         jffs2_free_xattr_datum(xd);
 626                 }
 627                 jffs2_free_xattr_ref(ref);
 628         }
 629         ic->xref = NULL;
 630         up_write(&c->xattr_sem);
 631 }
 632
 633 static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 634 {
 635         /* success of check_xattr_ref_inode() means that inode (ic) dose not have
 636          * duplicate name/value pairs. If duplicate name/value pair would be found,
 637          * one will be removed.
 638          */
 639         struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 640         int rc = 0;
 641
 642         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 643                 return 0;
 644         down_write(&c->xattr_sem);
 645  retry:
 646         rc = 0;
 647         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 648                 if (!ref->xd->xname) {
 649                         rc = load_xattr_datum(c, ref->xd);
 650                         if (unlikely(rc > 0)) {
 651                                 *pref = ref->next;
 652                                 delete_xattr_ref(c, ref);
 653                                 goto retry;
 654                         } else if (unlikely(rc < 0))
 655                                 goto out;
 656                 }
 657                 for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 658                         if (!cmp->xd->xname) {
 659                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
 660                                 rc = load_xattr_datum(c, cmp->xd);
 661                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 662                                 if (unlikely(rc > 0)) {
 663                                         *pcmp = cmp->next;
 664                                         delete_xattr_ref(c, cmp);
 665                                         goto retry;
 666                                 } else if (unlikely(rc < 0))
 667                                         goto out;
 668                         }
 669                         if (ref->xd->xprefix == cmp->xd->xprefix
 670                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 671                                 if (ref->xseqno > cmp->xseqno) {
 672                                         *pcmp = cmp->next;
 673                                         delete_xattr_ref(c, cmp);
 674                                 } else {
 675                                         *pref = ref->next;
 676                                         delete_xattr_ref(c, ref);
 677                                 }
 678                                 goto retry;
 679                         }
 680                 }
 681         }
 682         ic->flags |= INO_FLAGS_XATTR_CHECKED;
 683  out:
 684         up_write(&c->xattr_sem);
 685
 686         return rc;
 687 }
 688
 689 void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 690 {
 691         check_xattr_ref_inode(c, ic);
 692 }
 693
 694 /* -------- xattr subsystem functions ---------------
 695  * jffs2_init_xattr_subsystem(c)
 696  *   is used to initialize semaphore and list_head, and some variables.
 697  * jffs2_find_xattr_datum(c, xid)
 698  *   is used to lookup xdatum while scanning process.
 699  * jffs2_clear_xattr_subsystem(c)
 700  *   is used to release any xattr related objects.
 701  * jffs2_build_xattr_subsystem(c)
 702  *   is used to associate xdatum and xref while super block building process.
 703  * jffs2_setup_xattr_datum(c, xid, version)
 704  *   is used to insert xdatum while scanning process.
 705  * -------------------------------------------------- */
 706 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 707 {
 708         int i;
 709
 710         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 711                 INIT_LIST_HEAD(&c->xattrindex[i]);
 712         INIT_LIST_HEAD(&c->xattr_unchecked);
 713         INIT_LIST_HEAD(&c->xattr_dead_list);
 714         c->xref_dead_list = NULL;
 715         c->xref_temp = NULL;
 716
 717         init_rwsem(&c->xattr_sem);
 718         c->highest_xid = 0;
 719         c->highest_xseqno = 0;
 720         c->xdatum_mem_usage = 0;
 721         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 722 }
 723
 724 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 725 {
 726         struct jffs2_xattr_datum *xd;
 727         int i = xid % XATTRINDEX_HASHSIZE;
 728
 729         /* It's only used in scanning/building process. */
 730         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 731
 732         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 733                 if (xd->xid==xid)
 734                         return xd;
 735         }
 736         return NULL;
 737 }
 738
 739 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 740 {
 741         struct jffs2_xattr_datum *xd, *_xd;
 742         struct jffs2_xattr_ref *ref, *_ref;
 743         int i;
 744
 745         for (ref=c->xref_temp; ref; ref = _ref) {
 746                 _ref = ref->next;
 747                 jffs2_free_xattr_ref(ref);
 748         }
 749
 750         for (ref=c->xref_dead_list; ref; ref = _ref) {
 751                 _ref = ref->next;
 752                 jffs2_free_xattr_ref(ref);
 753         }
 754
 755         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 756                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 757                         list_del(&xd->xindex);
 758                         if (xd->xname)
 759                                 kfree(xd->xname);
 760                         jffs2_free_xattr_datum(xd);
 761                 }
 762         }
 763
 764         list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
 765                 list_del(&xd->xindex);
 766                 jffs2_free_xattr_datum(xd);
 767         }
 768         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
 769                 list_del(&xd->xindex);
 770                 jffs2_free_xattr_datum(xd);
 771         }
 772 }
 773
 774 #define XREF_TMPHASH_SIZE       (128)
 775 void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
 776 {
 777         struct jffs2_xattr_ref *ref, *_ref;
 778         struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
 779         struct jffs2_xattr_datum *xd, *_xd;
 780         struct jffs2_inode_cache *ic;
 781         struct jffs2_raw_node_ref *raw;
 782         int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
 783         int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
 784
 785         BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
 786
 787         /* Phase.1 : Merge same xref */
 788         for (i=0; i < XREF_TMPHASH_SIZE; i++)
 789                 xref_tmphash[i] = NULL;
 790         for (ref=c->xref_temp; ref; ref=_ref) {
 791                 struct jffs2_xattr_ref *tmp;
 792
 793                 _ref = ref->next;
 794                 if (ref_flags(ref->node) != REF_PRISTINE) {
 795                         if (verify_xattr_ref(c, ref)) {
 796                                 BUG_ON(ref->node->next_in_ino != (void *)ref);
 797                                 ref->node->next_in_ino = NULL;
 798                                 jffs2_mark_node_obsolete(c, ref->node);
 799                                 jffs2_free_xattr_ref(ref);
 800                                 continue;
 801                         }
 802                 }
 803
 804                 i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
 805                 for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
 806                         if (tmp->ino == ref->ino && tmp->xid == ref->xid)
 807                                 break;
 808                 }
 809                 if (tmp) {
 810                         raw = ref->node;
 811                         if (ref->xseqno > tmp->xseqno) {
 812                                 tmp->xseqno = ref->xseqno;
 813                                 raw->next_in_ino = tmp->node;
 814                                 tmp->node = raw;
 815                         } else {
 816                                 raw->next_in_ino = tmp->node->next_in_ino;
 817                                 tmp->node->next_in_ino = raw;
 818                         }
 819                         jffs2_free_xattr_ref(ref);
 820                         continue;
 821                 } else {
 822                         ref->next = xref_tmphash[i];
 823                         xref_tmphash[i] = ref;
 824                 }
 825         }
 826         c->xref_temp = NULL;
 827
 828         /* Phase.2 : Bind xref with inode_cache and xattr_datum */
 829         for (i=0; i < XREF_TMPHASH_SIZE; i++) {
 830                 for (ref=xref_tmphash[i]; ref; ref=_ref) {
 831                         xref_count++;
 832                         _ref = ref->next;
 833                         if (is_xattr_ref_dead(ref)) {
 834                                 ref->next = c->xref_dead_list;
 835                                 c->xref_dead_list = ref;
 836                                 xref_dead_count++;
 837                                 continue;
 838                         }
 839                         /* At this point, ref->xid and ref->ino contain XID and inode number.
 840                            ref->xd and ref->ic are not valid yet. */
 841                         xd = jffs2_find_xattr_datum(c, ref->xid);
 842                         ic = jffs2_get_ino_cache(c, ref->ino);
 843                         if (!xd || !ic || !ic->pino_nlink) {
 844                                 dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
 845                                           ref->ino, ref->xid, ref->xseqno);
 846                                 ref->xseqno |= XREF_DELETE_MARKER;
 847                                 ref->next = c->xref_dead_list;
 848                                 c->xref_dead_list = ref;
 849                                 xref_orphan_count++;
 850                                 continue;
 851                         }
 852                         ref->xd = xd;
 853                         ref->ic = ic;
 854                         atomic_inc(&xd->refcnt);
 855                         ref->next = ic->xref;
 856                         ic->xref = ref;
 857                 }
 858         }
 859
 860         /* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
 861         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 862                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 863                         xdatum_count++;
 864                         list_del_init(&xd->xindex);
 865                         if (!atomic_read(&xd->refcnt)) {
 866                                 dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
 867                                           xd->xid, xd->version);
 868                                 xd->flags |= JFFS2_XFLAGS_DEAD;
 869                                 list_add(&xd->xindex, &c->xattr_unchecked);
 870                                 xdatum_orphan_count++;
 871                                 continue;
 872                         }
 873                         if (is_xattr_datum_unchecked(c, xd)) {
 874                                 dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
 875                                           xd->xid, xd->version);
 876                                 list_add(&xd->xindex, &c->xattr_unchecked);
 877                                 xdatum_unchecked_count++;
 878                         }
 879                 }
 880         }
 881         /* build complete */
 882         JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
 883                      " (%u unchecked, %u orphan) and "
 884                      "%u of xref (%u dead, %u orphan) found.\n",
 885                      xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
 886                      xref_count, xref_dead_count, xref_orphan_count);
 887 }
 888
 889 struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
 890                                                   uint32_t xid, uint32_t version)
 891 {
 892         struct jffs2_xattr_datum *xd;
 893
 894         xd = jffs2_find_xattr_datum(c, xid);
 895         if (!xd) {
 896                 xd = jffs2_alloc_xattr_datum();
 897                 if (!xd)
 898                         return ERR_PTR(-ENOMEM);
 899                 xd->xid = xid;
 900                 xd->version = version;
 901                 if (xd->xid > c->highest_xid)
 902                         c->highest_xid = xd->xid;
 903                 list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
 904         }
 905         return xd;
 906 }
 907
 908 /* -------- xattr subsystem functions ---------------
 909  * xprefix_to_handler(xprefix)
 910  *   is used to translate xprefix into xattr_handler.
 911  * jffs2_listxattr(dentry, buffer, size)
 912  *   is an implementation of listxattr handler on jffs2.
 913  * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 914  *   is an implementation of getxattr handler on jffs2.
 915  * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 916  *   is an implementation of setxattr handler on jffs2.
 917  * -------------------------------------------------- */
 918 const struct xattr_handler *jffs2_xattr_handlers[] = {
 919         &jffs2_user_xattr_handler,
 920 #ifdef CONFIG_JFFS2_FS_SECURITY
 921         &jffs2_security_xattr_handler,
 922 #endif
 923 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 924         &jffs2_acl_access_xattr_handler,
 925         &jffs2_acl_default_xattr_handler,
 926 #endif
 927         &jffs2_trusted_xattr_handler,
 928         NULL
 929 };
 930
 931 static const struct xattr_handler *xprefix_to_handler(int xprefix) {
 932         const struct xattr_handler *ret;
 933
 934         switch (xprefix) {
 935         case JFFS2_XPREFIX_USER:
 936                 ret = &jffs2_user_xattr_handler;
 937                 break;
 938 #ifdef CONFIG_JFFS2_FS_SECURITY
 939         case JFFS2_XPREFIX_SECURITY:
 940                 ret = &jffs2_security_xattr_handler;
 941                 break;
 942 #endif
 943 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 944         case JFFS2_XPREFIX_ACL_ACCESS:
 945                 ret = &jffs2_acl_access_xattr_handler;
 946                 break;
 947         case JFFS2_XPREFIX_ACL_DEFAULT:
 948                 ret = &jffs2_acl_default_xattr_handler;
 949                 break;
 950 #endif
 951         case JFFS2_XPREFIX_TRUSTED:
 952                 ret = &jffs2_trusted_xattr_handler;
 953                 break;
 954         default:
 955                 ret = NULL;
 956                 break;
 957         }
 958         return ret;
 959 }
 960
 961 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 962 {
 963         struct inode *inode = dentry->d_inode;
 964         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 965         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 966         struct jffs2_inode_cache *ic = f->inocache;
 967         struct jffs2_xattr_ref *ref, **pref;
 968         struct jffs2_xattr_datum *xd;
 969         const struct xattr_handler *xhandle;
 970         ssize_t len, rc;
 971         int retry = 0;
 972
 973         rc = check_xattr_ref_inode(c, ic);
 974         if (unlikely(rc))
 975                 return rc;
 976
 977         down_read(&c->xattr_sem);
 978  retry:
 979         len = 0;
 980         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 981                 BUG_ON(ref->ic != ic);
 982                 xd = ref->xd;
 983                 if (!xd->xname) {
 984                         /* xdatum is unchached */
 985                         if (!retry) {
 986                                 retry = 1;
 987                                 up_read(&c->xattr_sem);
 988                                 down_write(&c->xattr_sem);
 989                                 goto retry;
 990                         } else {
 991                                 rc = load_xattr_datum(c, xd);
 992                                 if (unlikely(rc > 0)) {
 993                                         *pref = ref->next;
 994                                         delete_xattr_ref(c, ref);
 995                                         goto retry;
 996                                 } else if (unlikely(rc < 0))
 997                                         goto out;
 998                         }
 999                 }
1000                 xhandle = xprefix_to_handler(xd->xprefix);
1001                 if (!xhandle)
1002                         continue;
1003                 if (buffer) {
1004                         rc = xhandle->list(dentry, buffer+len, size-len,
1005                                            xd->xname, xd->name_len, xd->flags);
1006                 } else {
1007                         rc = xhandle->list(dentry, NULL, 0, xd->xname,
1008                                            xd->name_len, xd->flags);
1009                 }
1010                 if (rc < 0)
1011                         goto out;
1012                 len += rc;
1013         }
1014         rc = len;
1015  out:
1016         if (!retry) {
1017                 up_read(&c->xattr_sem);
1018         } else {
1019                 up_write(&c->xattr_sem);
1020         }
1021         return rc;
1022 }
1023
1024 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1025                       char *buffer, size_t size)
1026 {
1027         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1028         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1029         struct jffs2_inode_cache *ic = f->inocache;
1030         struct jffs2_xattr_datum *xd;
1031         struct jffs2_xattr_ref *ref, **pref;
1032         int rc, retry = 0;
1033
1034         rc = check_xattr_ref_inode(c, ic);
1035         if (unlikely(rc))
1036                 return rc;
1037
1038         down_read(&c->xattr_sem);
1039  retry:
1040         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1041                 BUG_ON(ref->ic!=ic);
1042
1043                 xd = ref->xd;
1044                 if (xd->xprefix != xprefix)
1045                         continue;
1046                 if (!xd->xname) {
1047                         /* xdatum is unchached */
1048                         if (!retry) {
1049                                 retry = 1;
1050                                 up_read(&c->xattr_sem);
1051                                 down_write(&c->xattr_sem);
1052                                 goto retry;
1053                         } else {
1054                                 rc = load_xattr_datum(c, xd);
1055                                 if (unlikely(rc > 0)) {
1056                                         *pref = ref->next;
1057                                         delete_xattr_ref(c, ref);
1058                                         goto retry;
1059                                 } else if (unlikely(rc < 0)) {
1060                                         goto out;
1061                                 }
1062                         }
1063                 }
1064                 if (!strcmp(xname, xd->xname)) {
1065                         rc = xd->value_len;
1066                         if (buffer) {
1067                                 if (size < rc) {
1068                                         rc = -ERANGE;
1069                                 } else {
1070                                         memcpy(buffer, xd->xvalue, rc);
1071                                 }
1072                         }
1073                         goto out;
1074                 }
1075         }
1076         rc = -ENODATA;
1077  out:
1078         if (!retry) {
1079                 up_read(&c->xattr_sem);
1080         } else {
1081                 up_write(&c->xattr_sem);
1082         }
1083         return rc;
1084 }
1085
1086 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1087                       const char *buffer, size_t size, int flags)
1088 {
1089         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1090         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1091         struct jffs2_inode_cache *ic = f->inocache;
1092         struct jffs2_xattr_datum *xd;
1093         struct jffs2_xattr_ref *ref, *newref, **pref;
1094         uint32_t length, request;
1095         int rc;
1096
1097         rc = check_xattr_ref_inode(c, ic);
1098         if (unlikely(rc))
1099                 return rc;
1100
1101         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1102         rc = jffs2_reserve_space(c, request, &length,
1103                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1104         if (rc) {
1105                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1106                 return rc;
1107         }
1108
1109         /* Find existing xattr */
1110         down_write(&c->xattr_sem);
1111  retry:
1112         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1113                 xd = ref->xd;
1114                 if (xd->xprefix != xprefix)
1115                         continue;
1116                 if (!xd->xname) {
1117                         rc = load_xattr_datum(c, xd);
1118                         if (unlikely(rc > 0)) {
1119                                 *pref = ref->next;
1120                                 delete_xattr_ref(c, ref);
1121                                 goto retry;
1122                         } else if (unlikely(rc < 0))
1123                                 goto out;
1124                 }
1125                 if (!strcmp(xd->xname, xname)) {
1126                         if (flags & XATTR_CREATE) {
1127                                 rc = -EEXIST;
1128                                 goto out;
1129                         }
1130                         if (!buffer) {
1131                                 ref->ino = ic->ino;
1132                                 ref->xid = xd->xid;
1133                                 ref->xseqno |= XREF_DELETE_MARKER;
1134                                 rc = save_xattr_ref(c, ref);
1135                                 if (!rc) {
1136                                         *pref = ref->next;
1137                                         spin_lock(&c->erase_completion_lock);
1138                                         ref->next = c->xref_dead_list;
1139                                         c->xref_dead_list = ref;
1140                                         spin_unlock(&c->erase_completion_lock);
1141                                         unrefer_xattr_datum(c, xd);
1142                                 } else {
1143                                         ref->ic = ic;
1144                                         ref->xd = xd;
1145                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1146                                 }
1147                                 goto out;
1148                         }
1149                         goto found;
1150                 }
1151         }
1152         /* not found */
1153         if (flags & XATTR_REPLACE) {
1154                 rc = -ENODATA;
1155                 goto out;
1156         }
1157         if (!buffer) {
1158                 rc = -ENODATA;
1159                 goto out;
1160         }
1161  found:
1162         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1163         if (IS_ERR(xd)) {
1164                 rc = PTR_ERR(xd);
1165                 goto out;
1166         }
1167         up_write(&c->xattr_sem);
1168         jffs2_complete_reservation(c);
1169
1170         /* create xattr_ref */
1171         request = PAD(sizeof(struct jffs2_raw_xref));
1172         rc = jffs2_reserve_space(c, request, &length,
1173                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1174         down_write(&c->xattr_sem);
1175         if (rc) {
1176                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1177                 unrefer_xattr_datum(c, xd);
1178                 up_write(&c->xattr_sem);
1179                 return rc;
1180         }
1181         if (ref)
1182                 *pref = ref->next;
1183         newref = create_xattr_ref(c, ic, xd);
1184         if (IS_ERR(newref)) {
1185                 if (ref) {
1186                         ref->next = ic->xref;
1187                         ic->xref = ref;
1188                 }
1189                 rc = PTR_ERR(newref);
1190                 unrefer_xattr_datum(c, xd);
1191         } else if (ref) {
1192                 delete_xattr_ref(c, ref);
1193         }
1194  out:
1195         up_write(&c->xattr_sem);
1196         jffs2_complete_reservation(c);
1197         return rc;
1198 }
1199
1200 /* -------- garbage collector functions -------------
1201  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1202  *   is used to move xdatum into new node.
1203  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1204  *   is used to move xref into new node.
1205  * jffs2_verify_xattr(c)
1206  *   is used to call do_verify_xattr_datum() before garbage collecting.
1207  * jffs2_release_xattr_datum(c, xd)
1208  *   is used to release an in-memory object of xdatum.
1209  * jffs2_release_xattr_ref(c, ref)
1210  *   is used to release an in-memory object of xref.
1211  * -------------------------------------------------- */
1212 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1213                                       struct jffs2_raw_node_ref *raw)
1214 {
1215         uint32_t totlen, length, old_ofs;
1216         int rc = 0;
1217
1218         down_write(&c->xattr_sem);
1219         if (xd->node != raw)
1220                 goto out;
1221         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1222                 goto out;
1223
1224         rc = load_xattr_datum(c, xd);
1225         if (unlikely(rc)) {
1226                 rc = (rc > 0) ? 0 : rc;
1227                 goto out;
1228         }
1229         old_ofs = ref_offset(xd->node);
1230         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1231                         + xd->name_len + 1 + xd->value_len);
1232         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1233         if (rc) {
1234                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1235                 goto out;
1236         }
1237         rc = save_xattr_datum(c, xd);
1238         if (!rc)
1239                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1240                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1241  out:
1242         if (!rc)
1243                 jffs2_mark_node_obsolete(c, raw);
1244         up_write(&c->xattr_sem);
1245         return rc;
1246 }
1247
1248 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1249                                     struct jffs2_raw_node_ref *raw)
1250 {
1251         uint32_t totlen, length, old_ofs;
1252         int rc = 0;
1253
1254         down_write(&c->xattr_sem);
1255         BUG_ON(!ref->node);
1256
1257         if (ref->node != raw)
1258                 goto out;
1259         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1260                 goto out;
1261
1262         old_ofs = ref_offset(ref->node);
1263         totlen = ref_totlen(c, c->gcblock, ref->node);
1264
1265         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1266         if (rc) {
1267                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1268                               __func__, rc, totlen);
1269                 rc = rc ? rc : -EBADFD;
1270                 goto out;
1271         }
1272         rc = save_xattr_ref(c, ref);
1273         if (!rc)
1274                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1275                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1276  out:
1277         if (!rc)
1278                 jffs2_mark_node_obsolete(c, raw);
1279         up_write(&c->xattr_sem);
1280         return rc;
1281 }
1282
1283 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1284 {
1285         struct jffs2_xattr_datum *xd, *_xd;
1286         struct jffs2_eraseblock *jeb;
1287         struct jffs2_raw_node_ref *raw;
1288         uint32_t totlen;
1289         int rc;
1290
1291         down_write(&c->xattr_sem);
1292         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1293                 rc = do_verify_xattr_datum(c, xd);
1294                 if (rc < 0)
1295                         continue;
1296                 list_del_init(&xd->xindex);
1297                 spin_lock(&c->erase_completion_lock);
1298                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1299                         if (ref_flags(raw) != REF_UNCHECKED)
1300                                 continue;
1301                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1302                         totlen = PAD(ref_totlen(c, jeb, raw));
1303                         c->unchecked_size -= totlen; c->used_size += totlen;
1304                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1305                         raw->flash_offset = ref_offset(raw)
1306                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1307                 }
1308                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1309                         list_add(&xd->xindex, &c->xattr_dead_list);
1310                 spin_unlock(&c->erase_completion_lock);
1311         }
1312         up_write(&c->xattr_sem);
1313         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1314 }
1315
1316 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1317 {
1318         /* must be called under spin_lock(&c->erase_completion_lock) */
1319         if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1320                 return;
1321
1322         list_del(&xd->xindex);
1323         jffs2_free_xattr_datum(xd);
1324 }
1325
1326 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1327 {
1328         /* must be called under spin_lock(&c->erase_completion_lock) */
1329         struct jffs2_xattr_ref *tmp, **ptmp;
1330
1331         if (ref->node != (void *)ref)
1332                 return;
1333
1334         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1335                 if (ref == tmp) {
1336                         *ptmp = tmp->next;
1337                         break;
1338                 }
1339         }
1340         jffs2_free_xattr_ref(ref);
1341 }