fs/jffs2/xattr.c

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This source file includes following definitions.
xattr_datum_hashkey
is_xattr_datum_unchecked
unload_xattr_datum
reclaim_xattr_datum
do_verify_xattr_datum
do_load_xattr_datum
load_xattr_datum
save_xattr_datum
create_xattr_datum
unrefer_xattr_datum
verify_xattr_ref
save_xattr_ref
create_xattr_ref
delete_xattr_ref
jffs2_xattr_delete_inode
jffs2_xattr_free_inode
check_xattr_ref_inode
jffs2_xattr_do_crccheck_inode
jffs2_init_xattr_subsystem
jffs2_find_xattr_datum
jffs2_clear_xattr_subsystem
jffs2_build_xattr_subsystem
jffs2_setup_xattr_datum
xprefix_to_handler
jffs2_listxattr
do_jffs2_getxattr
do_jffs2_setxattr
jffs2_garbage_collect_xattr_datum
jffs2_garbage_collect_xattr_ref
jffs2_verify_xattr
jffs2_release_xattr_datum
jffs2_release_xattr_ref
   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/posix_acl_xattr.h>
  26 #include <linux/mtd/mtd.h>
  27 #include "nodelist.h"
  28 /* -------- xdatum related functions ----------------
  29  * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  30  *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  31  *   the index of the xattr name/value pair cache (c->xattrindex).
  32  * is_xattr_datum_unchecked(c, xd)
  33  *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  34  *   unchecked, it returns 0.
  35  * unload_xattr_datum(c, xd)
  36  *   is used to release xattr name/value pair and detach from c->xattrindex.
  37  * reclaim_xattr_datum(c)
  38  *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  39  *   memory usage by cache is over c->xdatum_mem_threshold. Currently, this threshold
  40  *   is hard coded as 32KiB.
  41  * do_verify_xattr_datum(c, xd)
  42  *   is used to load the xdatum informations without name/value pair from the medium.
  43  *   It's necessary once, because those informations are not collected during mounting
  44  *   process when EBS is enabled.
  45  *   0 will be returned, if success. An negative return value means recoverable error, and
  46  *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  47  *   and xref when it returned positive value.
  48  * do_load_xattr_datum(c, xd)
  49  *   is used to load name/value pair from the medium.
  50  *   The meanings of return value is same as do_verify_xattr_datum().
  51  * load_xattr_datum(c, xd)
  52  *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  53  *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  54  *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  55  * save_xattr_datum(c, xd)
  56  *   is used to write xdatum to medium. xd->version will be incremented.
  57  * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  58  *   is used to create new xdatum and write to medium.
  59  * unrefer_xattr_datum(c, xd)
  60  *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
  61  *   is set on xd->flags and chained xattr_dead_list or release it immediately.
  62  *   In the first case, the garbage collector release it later.
  63  * -------------------------------------------------- */
  64 static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
  65 {
  66         int name_len = strlen(xname);
  67 
  68         return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
  69 }
  70 
  71 static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  72 {
  73         struct jffs2_raw_node_ref *raw;
  74         int rc = 0;
  75 
  76         spin_lock(&c->erase_completion_lock);
  77         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
  78                 if (ref_flags(raw) == REF_UNCHECKED) {
  79                         rc = 1;
  80                         break;
  81                 }
  82         }
  83         spin_unlock(&c->erase_completion_lock);
  84         return rc;
  85 }
  86 
  87 static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  88 {
  89         /* must be called under down_write(xattr_sem) */
  90         D1(dbg_xattr("%s: xid=%u, version=%u\n", __func__, xd->xid, xd->version));
  91         if (xd->xname) {
  92                 c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  93                 kfree(xd->xname);
  94         }
  95 
  96         list_del_init(&xd->xindex);
  97         xd->hashkey = 0;
  98         xd->xname = NULL;
  99         xd->xvalue = NULL;
 100 }
 101 
 102 static void reclaim_xattr_datum(struct jffs2_sb_info *c)
 103 {
 104         /* must be called under down_write(xattr_sem) */
 105         struct jffs2_xattr_datum *xd, *_xd;
 106         uint32_t target, before;
 107         static int index = 0;
 108         int count;
 109 
 110         if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
 111                 return;
 112 
 113         before = c->xdatum_mem_usage;
 114         target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
 115         for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
 116                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
 117                         if (xd->flags & JFFS2_XFLAGS_HOT) {
 118                                 xd->flags &= ~JFFS2_XFLAGS_HOT;
 119                         } else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
 120                                 unload_xattr_datum(c, xd);
 121                         }
 122                         if (c->xdatum_mem_usage <= target)
 123                                 goto out;
 124                 }
 125                 index = (index+1) % XATTRINDEX_HASHSIZE;
 126         }
 127  out:
 128         JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 129                      before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 130 }
 131 
 132 static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 133 {
 134         /* must be called under down_write(xattr_sem) */
 135         struct jffs2_eraseblock *jeb;
 136         struct jffs2_raw_node_ref *raw;
 137         struct jffs2_raw_xattr rx;
 138         size_t readlen;
 139         uint32_t crc, offset, totlen;
 140         int rc;
 141 
 142         spin_lock(&c->erase_completion_lock);
 143         offset = ref_offset(xd->node);
 144         if (ref_flags(xd->node) == REF_PRISTINE)
 145                 goto complete;
 146         spin_unlock(&c->erase_completion_lock);
 147 
 148         rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
 149         if (rc || readlen != sizeof(rx)) {
 150                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
 151                               rc, sizeof(rx), readlen, offset);
 152                 return rc ? rc : -EIO;
 153         }
 154         crc = crc32(0, &rx, sizeof(rx) - 4);
 155         if (crc != je32_to_cpu(rx.node_crc)) {
 156                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 157                             offset, je32_to_cpu(rx.hdr_crc), crc);
 158                 xd->flags |= JFFS2_XFLAGS_INVALID;
 159                 return JFFS2_XATTR_IS_CORRUPTED;
 160         }
 161         totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 162         if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 163             || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 164             || je32_to_cpu(rx.totlen) != totlen
 165             || je32_to_cpu(rx.xid) != xd->xid
 166             || je32_to_cpu(rx.version) != xd->version) {
 167                 JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 168                             "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 169                             offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
 170                             je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
 171                             je32_to_cpu(rx.totlen), totlen,
 172                             je32_to_cpu(rx.xid), xd->xid,
 173                             je32_to_cpu(rx.version), xd->version);
 174                 xd->flags |= JFFS2_XFLAGS_INVALID;
 175                 return JFFS2_XATTR_IS_CORRUPTED;
 176         }
 177         xd->xprefix = rx.xprefix;
 178         xd->name_len = rx.name_len;
 179         xd->value_len = je16_to_cpu(rx.value_len);
 180         xd->data_crc = je32_to_cpu(rx.data_crc);
 181 
 182         spin_lock(&c->erase_completion_lock);
 183  complete:
 184         for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
 185                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 186                 totlen = PAD(ref_totlen(c, jeb, raw));
 187                 if (ref_flags(raw) == REF_UNCHECKED) {
 188                         c->unchecked_size -= totlen; c->used_size += totlen;
 189                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 190                 }
 191                 raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
 192         }
 193         spin_unlock(&c->erase_completion_lock);
 194 
 195         /* unchecked xdatum is chained with c->xattr_unchecked */
 196         list_del_init(&xd->xindex);
 197 
 198         dbg_xattr("success on verifying xdatum (xid=%u, version=%u)\n",
 199                   xd->xid, xd->version);
 200 
 201         return 0;
 202 }
 203 
 204 static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 205 {
 206         /* must be called under down_write(xattr_sem) */
 207         char *data;
 208         size_t readlen;
 209         uint32_t crc, length;
 210         int i, ret, retry = 0;
 211 
 212         BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 213         BUG_ON(!list_empty(&xd->xindex));
 214  retry:
 215         length = xd->name_len + 1 + xd->value_len;
 216         data = kmalloc(length, GFP_KERNEL);
 217         if (!data)
 218                 return -ENOMEM;
 219 
 220         ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 221                                length, &readlen, data);
 222 
 223         if (ret || length!=readlen) {
 224                 JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
 225                               ret, length, readlen, ref_offset(xd->node));
 226                 kfree(data);
 227                 return ret ? ret : -EIO;
 228         }
 229 
 230         data[xd->name_len] = '\0';
 231         crc = crc32(0, data, length);
 232         if (crc != xd->data_crc) {
 233                 JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XATTR)"
 234                               " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 235                               ref_offset(xd->node), xd->data_crc, crc);
 236                 kfree(data);
 237                 xd->flags |= JFFS2_XFLAGS_INVALID;
 238                 return JFFS2_XATTR_IS_CORRUPTED;
 239         }
 240 
 241         xd->flags |= JFFS2_XFLAGS_HOT;
 242         xd->xname = data;
 243         xd->xvalue = data + xd->name_len+1;
 244 
 245         c->xdatum_mem_usage += length;
 246 
 247         xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 248         i = xd->hashkey % XATTRINDEX_HASHSIZE;
 249         list_add(&xd->xindex, &c->xattrindex[i]);
 250         if (!retry) {
 251                 retry = 1;
 252                 reclaim_xattr_datum(c);
 253                 if (!xd->xname)
 254                         goto retry;
 255         }
 256 
 257         dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 258                   xd->xid, xd->xprefix, xd->xname);
 259 
 260         return 0;
 261 }
 262 
 263 static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 264 {
 265         /* must be called under down_write(xattr_sem);
 266          * rc < 0 : recoverable error, try again
 267          * rc = 0 : success
 268          * rc > 0 : Unrecoverable error, this node should be deleted.
 269          */
 270         int rc = 0;
 271 
 272         BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
 273         if (xd->xname)
 274                 return 0;
 275         if (xd->flags & JFFS2_XFLAGS_INVALID)
 276                 return JFFS2_XATTR_IS_CORRUPTED;
 277         if (unlikely(is_xattr_datum_unchecked(c, xd)))
 278                 rc = do_verify_xattr_datum(c, xd);
 279         if (!rc)
 280                 rc = do_load_xattr_datum(c, xd);
 281         return rc;
 282 }
 283 
 284 static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 285 {
 286         /* must be called under down_write(xattr_sem) */
 287         struct jffs2_raw_xattr rx;
 288         struct kvec vecs[2];
 289         size_t length;
 290         int rc, totlen;
 291         uint32_t phys_ofs = write_ofs(c);
 292 
 293         BUG_ON(!xd->xname);
 294         BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
 295 
 296         vecs[0].iov_base = &rx;
 297         vecs[0].iov_len = sizeof(rx);
 298         vecs[1].iov_base = xd->xname;
 299         vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 300         totlen = vecs[0].iov_len + vecs[1].iov_len;
 301 
 302         /* Setup raw-xattr */
 303         memset(&rx, 0, sizeof(rx));
 304         rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 305         rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 306         rx.totlen = cpu_to_je32(PAD(totlen));
 307         rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 308 
 309         rx.xid = cpu_to_je32(xd->xid);
 310         rx.version = cpu_to_je32(++xd->version);
 311         rx.xprefix = xd->xprefix;
 312         rx.name_len = xd->name_len;
 313         rx.value_len = cpu_to_je16(xd->value_len);
 314         rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 315         rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 316 
 317         rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 318         if (rc || totlen != length) {
 319                 JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
 320                               rc, totlen, length, phys_ofs);
 321                 rc = rc ? rc : -EIO;
 322                 if (length)
 323                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
 324 
 325                 return rc;
 326         }
 327         /* success */
 328         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
 329 
 330         dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 331                   xd->xid, xd->version, xd->xprefix, xd->xname);
 332 
 333         return 0;
 334 }
 335 
 336 static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 337                                                     int xprefix, const char *xname,
 338                                                     const char *xvalue, int xsize)
 339 {
 340         /* must be called under down_write(xattr_sem) */
 341         struct jffs2_xattr_datum *xd;
 342         uint32_t hashkey, name_len;
 343         char *data;
 344         int i, rc;
 345 
 346         /* Search xattr_datum has same xname/xvalue by index */
 347         hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 348         i = hashkey % XATTRINDEX_HASHSIZE;
 349         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 350                 if (xd->hashkey==hashkey
 351                     && xd->xprefix==xprefix
 352                     && xd->value_len==xsize
 353                     && !strcmp(xd->xname, xname)
 354                     && !memcmp(xd->xvalue, xvalue, xsize)) {
 355                         atomic_inc(&xd->refcnt);
 356                         return xd;
 357                 }
 358         }
 359 
 360         /* Not found, Create NEW XATTR-Cache */
 361         name_len = strlen(xname);
 362 
 363         xd = jffs2_alloc_xattr_datum();
 364         if (!xd)
 365                 return ERR_PTR(-ENOMEM);
 366 
 367         data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 368         if (!data) {
 369                 jffs2_free_xattr_datum(xd);
 370                 return ERR_PTR(-ENOMEM);
 371         }
 372         strcpy(data, xname);
 373         memcpy(data + name_len + 1, xvalue, xsize);
 374 
 375         atomic_set(&xd->refcnt, 1);
 376         xd->xid = ++c->highest_xid;
 377         xd->flags |= JFFS2_XFLAGS_HOT;
 378         xd->xprefix = xprefix;
 379 
 380         xd->hashkey = hashkey;
 381         xd->xname = data;
 382         xd->xvalue = data + name_len + 1;
 383         xd->name_len = name_len;
 384         xd->value_len = xsize;
 385         xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 386 
 387         rc = save_xattr_datum(c, xd);
 388         if (rc) {
 389                 kfree(xd->xname);
 390                 jffs2_free_xattr_datum(xd);
 391                 return ERR_PTR(rc);
 392         }
 393 
 394         /* Insert Hash Index */
 395         i = hashkey % XATTRINDEX_HASHSIZE;
 396         list_add(&xd->xindex, &c->xattrindex[i]);
 397 
 398         c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 399         reclaim_xattr_datum(c);
 400 
 401         return xd;
 402 }
 403 
 404 static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 405 {
 406         /* must be called under down_write(xattr_sem) */
 407         if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
 408                 unload_xattr_datum(c, xd);
 409                 xd->flags |= JFFS2_XFLAGS_DEAD;
 410                 if (xd->node == (void *)xd) {
 411                         BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 412                         jffs2_free_xattr_datum(xd);
 413                 } else {
 414                         list_add(&xd->xindex, &c->xattr_dead_list);
 415                 }
 416                 spin_unlock(&c->erase_completion_lock);
 417 
 418                 dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
 419                           xd->xid, xd->version);
 420         }
 421 }
 422 
 423 /* -------- xref related functions ------------------
 424  * verify_xattr_ref(c, ref)
 425  *   is used to load xref information from medium. Because summary data does not
 426  *   contain xid/ino, it's necessary to verify once while mounting process.
 427  * save_xattr_ref(c, ref)
 428  *   is used to write xref to medium. If delete marker is marked, it write
 429  *   a delete marker of xref into medium.
 430  * create_xattr_ref(c, ic, xd)
 431  *   is used to create a new xref and write to medium.
 432  * delete_xattr_ref(c, ref)
 433  *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 434  *   and allows GC to reclaim those physical nodes.
 435  * jffs2_xattr_delete_inode(c, ic)
 436  *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 437  * jffs2_xattr_free_inode(c, ic)
 438  *   is called to release xattr related objects when unmounting. 
 439  * check_xattr_ref_inode(c, ic)
 440  *   is used to confirm inode does not have duplicate xattr name/value pair.
 441  * jffs2_xattr_do_crccheck_inode(c, ic)
 442  *   is used to force xattr data integrity check during the initial gc scan.
 443  * -------------------------------------------------- */
 444 static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 445 {
 446         struct jffs2_eraseblock *jeb;
 447         struct jffs2_raw_node_ref *raw;
 448         struct jffs2_raw_xref rr;
 449         size_t readlen;
 450         uint32_t crc, offset, totlen;
 451         int rc;
 452 
 453         spin_lock(&c->erase_completion_lock);
 454         if (ref_flags(ref->node) != REF_UNCHECKED)
 455                 goto complete;
 456         offset = ref_offset(ref->node);
 457         spin_unlock(&c->erase_completion_lock);
 458 
 459         rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
 460         if (rc || sizeof(rr) != readlen) {
 461                 JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
 462                               rc, sizeof(rr), readlen, offset);
 463                 return rc ? rc : -EIO;
 464         }
 465         /* obsolete node */
 466         crc = crc32(0, &rr, sizeof(rr) - 4);
 467         if (crc != je32_to_cpu(rr.node_crc)) {
 468                 JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 469                             offset, je32_to_cpu(rr.node_crc), crc);
 470                 return JFFS2_XATTR_IS_CORRUPTED;
 471         }
 472         if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 473             || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 474             || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 475                 JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 476                             "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
 477                             offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 478                             je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 479                             je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 480                 return JFFS2_XATTR_IS_CORRUPTED;
 481         }
 482         ref->ino = je32_to_cpu(rr.ino);
 483         ref->xid = je32_to_cpu(rr.xid);
 484         ref->xseqno = je32_to_cpu(rr.xseqno);
 485         if (ref->xseqno > c->highest_xseqno)
 486                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 487 
 488         spin_lock(&c->erase_completion_lock);
 489  complete:
 490         for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
 491                 jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 492                 totlen = PAD(ref_totlen(c, jeb, raw));
 493                 if (ref_flags(raw) == REF_UNCHECKED) {
 494                         c->unchecked_size -= totlen; c->used_size += totlen;
 495                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 496                 }
 497                 raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
 498         }
 499         spin_unlock(&c->erase_completion_lock);
 500 
 501         dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 502                   ref->ino, ref->xid, ref_offset(ref->node));
 503         return 0;
 504 }
 505 
 506 static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 507 {
 508         /* must be called under down_write(xattr_sem) */
 509         struct jffs2_raw_xref rr;
 510         size_t length;
 511         uint32_t xseqno, phys_ofs = write_ofs(c);
 512         int ret;
 513 
 514         rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 515         rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 516         rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 517         rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 518 
 519         xseqno = (c->highest_xseqno += 2);
 520         if (is_xattr_ref_dead(ref)) {
 521                 xseqno |= XREF_DELETE_MARKER;
 522                 rr.ino = cpu_to_je32(ref->ino);
 523                 rr.xid = cpu_to_je32(ref->xid);
 524         } else {
 525                 rr.ino = cpu_to_je32(ref->ic->ino);
 526                 rr.xid = cpu_to_je32(ref->xd->xid);
 527         }
 528         rr.xseqno = cpu_to_je32(xseqno);
 529         rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 530 
 531         ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 532         if (ret || sizeof(rr) != length) {
 533                 JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
 534                               ret, sizeof(rr), length, phys_ofs);
 535                 ret = ret ? ret : -EIO;
 536                 if (length)
 537                         jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
 538 
 539                 return ret;
 540         }
 541         /* success */
 542         ref->xseqno = xseqno;
 543         jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
 544 
 545         dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 546 
 547         return 0;
 548 }
 549 
 550 static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 551                                                 struct jffs2_xattr_datum *xd)
 552 {
 553         /* must be called under down_write(xattr_sem) */
 554         struct jffs2_xattr_ref *ref;
 555         int ret;
 556 
 557         ref = jffs2_alloc_xattr_ref();
 558         if (!ref)
 559                 return ERR_PTR(-ENOMEM);
 560         ref->ic = ic;
 561         ref->xd = xd;
 562 
 563         ret = save_xattr_ref(c, ref);
 564         if (ret) {
 565                 jffs2_free_xattr_ref(ref);
 566                 return ERR_PTR(ret);
 567         }
 568 
 569         /* Chain to inode */
 570         ref->next = ic->xref;
 571         ic->xref = ref;
 572 
 573         return ref; /* success */
 574 }
 575 
 576 static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 577 {
 578         /* must be called under down_write(xattr_sem) */
 579         struct jffs2_xattr_datum *xd;
 580 
 581         xd = ref->xd;
 582         ref->xseqno |= XREF_DELETE_MARKER;
 583         ref->ino = ref->ic->ino;
 584         ref->xid = ref->xd->xid;
 585         spin_lock(&c->erase_completion_lock);
 586         ref->next = c->xref_dead_list;
 587         c->xref_dead_list = ref;
 588         spin_unlock(&c->erase_completion_lock);
 589 
 590         dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
 591                   ref->ino, ref->xid, ref->xseqno);
 592 
 593         unrefer_xattr_datum(c, xd);
 594 }
 595 
 596 void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 597 {
 598         /* It's called from jffs2_evict_inode() on inode removing.
 599            When an inode with XATTR is removed, those XATTRs must be removed. */
 600         struct jffs2_xattr_ref *ref, *_ref;
 601 
 602         if (!ic || ic->pino_nlink > 0)
 603                 return;
 604 
 605         down_write(&c->xattr_sem);
 606         for (ref = ic->xref; ref; ref = _ref) {
 607                 _ref = ref->next;
 608                 delete_xattr_ref(c, ref);
 609         }
 610         ic->xref = NULL;
 611         up_write(&c->xattr_sem);
 612 }
 613 
 614 void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 615 {
 616         /* It's called from jffs2_free_ino_caches() until unmounting FS. */
 617         struct jffs2_xattr_datum *xd;
 618         struct jffs2_xattr_ref *ref, *_ref;
 619 
 620         down_write(&c->xattr_sem);
 621         for (ref = ic->xref; ref; ref = _ref) {
 622                 _ref = ref->next;
 623                 xd = ref->xd;
 624                 if (atomic_dec_and_test(&xd->refcnt)) {
 625                         unload_xattr_datum(c, xd);
 626                         jffs2_free_xattr_datum(xd);
 627                 }
 628                 jffs2_free_xattr_ref(ref);
 629         }
 630         ic->xref = NULL;
 631         up_write(&c->xattr_sem);
 632 }
 633 
 634 static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 635 {
 636         /* success of check_xattr_ref_inode() means that inode (ic) dose not have
 637          * duplicate name/value pairs. If duplicate name/value pair would be found,
 638          * one will be removed.
 639          */
 640         struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 641         int rc = 0;
 642 
 643         if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 644                 return 0;
 645         down_write(&c->xattr_sem);
 646  retry:
 647         rc = 0;
 648         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 649                 if (!ref->xd->xname) {
 650                         rc = load_xattr_datum(c, ref->xd);
 651                         if (unlikely(rc > 0)) {
 652                                 *pref = ref->next;
 653                                 delete_xattr_ref(c, ref);
 654                                 goto retry;
 655                         } else if (unlikely(rc < 0))
 656                                 goto out;
 657                 }
 658                 for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 659                         if (!cmp->xd->xname) {
 660                                 ref->xd->flags |= JFFS2_XFLAGS_BIND;
 661                                 rc = load_xattr_datum(c, cmp->xd);
 662                                 ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 663                                 if (unlikely(rc > 0)) {
 664                                         *pcmp = cmp->next;
 665                                         delete_xattr_ref(c, cmp);
 666                                         goto retry;
 667                                 } else if (unlikely(rc < 0))
 668                                         goto out;
 669                         }
 670                         if (ref->xd->xprefix == cmp->xd->xprefix
 671                             && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 672                                 if (ref->xseqno > cmp->xseqno) {
 673                                         *pcmp = cmp->next;
 674                                         delete_xattr_ref(c, cmp);
 675                                 } else {
 676                                         *pref = ref->next;
 677                                         delete_xattr_ref(c, ref);
 678                                 }
 679                                 goto retry;
 680                         }
 681                 }
 682         }
 683         ic->flags |= INO_FLAGS_XATTR_CHECKED;
 684  out:
 685         up_write(&c->xattr_sem);
 686 
 687         return rc;
 688 }
 689 
 690 void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 691 {
 692         check_xattr_ref_inode(c, ic);
 693 }
 694 
 695 /* -------- xattr subsystem functions ---------------
 696  * jffs2_init_xattr_subsystem(c)
 697  *   is used to initialize semaphore and list_head, and some variables.
 698  * jffs2_find_xattr_datum(c, xid)
 699  *   is used to lookup xdatum while scanning process.
 700  * jffs2_clear_xattr_subsystem(c)
 701  *   is used to release any xattr related objects.
 702  * jffs2_build_xattr_subsystem(c)
 703  *   is used to associate xdatum and xref while super block building process.
 704  * jffs2_setup_xattr_datum(c, xid, version)
 705  *   is used to insert xdatum while scanning process.
 706  * -------------------------------------------------- */
 707 void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 708 {
 709         int i;
 710 
 711         for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 712                 INIT_LIST_HEAD(&c->xattrindex[i]);
 713         INIT_LIST_HEAD(&c->xattr_unchecked);
 714         INIT_LIST_HEAD(&c->xattr_dead_list);
 715         c->xref_dead_list = NULL;
 716         c->xref_temp = NULL;
 717 
 718         init_rwsem(&c->xattr_sem);
 719         c->highest_xid = 0;
 720         c->highest_xseqno = 0;
 721         c->xdatum_mem_usage = 0;
 722         c->xdatum_mem_threshold = 32 * 1024;    /* Default 32KB */
 723 }
 724 
 725 static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 726 {
 727         struct jffs2_xattr_datum *xd;
 728         int i = xid % XATTRINDEX_HASHSIZE;
 729 
 730         /* It's only used in scanning/building process. */
 731         BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 732 
 733         list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 734                 if (xd->xid==xid)
 735                         return xd;
 736         }
 737         return NULL;
 738 }
 739 
 740 void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 741 {
 742         struct jffs2_xattr_datum *xd, *_xd;
 743         struct jffs2_xattr_ref *ref, *_ref;
 744         int i;
 745 
 746         for (ref=c->xref_temp; ref; ref = _ref) {
 747                 _ref = ref->next;
 748                 jffs2_free_xattr_ref(ref);
 749         }
 750 
 751         for (ref=c->xref_dead_list; ref; ref = _ref) {
 752                 _ref = ref->next;
 753                 jffs2_free_xattr_ref(ref);
 754         }
 755 
 756         for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 757                 list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 758                         list_del(&xd->xindex);
 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         &posix_acl_access_xattr_handler,
 925         &posix_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 = &posix_acl_access_xattr_handler;
 946                 break;
 947         case JFFS2_XPREFIX_ACL_DEFAULT:
 948                 ret = &posix_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 = d_inode(dentry);
 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         const char *prefix;
 971         ssize_t prefix_len, len, rc;
 972         int retry = 0;
 973 
 974         rc = check_xattr_ref_inode(c, ic);
 975         if (unlikely(rc))
 976                 return rc;
 977 
 978         down_read(&c->xattr_sem);
 979  retry:
 980         len = 0;
 981         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 982                 BUG_ON(ref->ic != ic);
 983                 xd = ref->xd;
 984                 if (!xd->xname) {
 985                         /* xdatum is unchached */
 986                         if (!retry) {
 987                                 retry = 1;
 988                                 up_read(&c->xattr_sem);
 989                                 down_write(&c->xattr_sem);
 990                                 goto retry;
 991                         } else {
 992                                 rc = load_xattr_datum(c, xd);
 993                                 if (unlikely(rc > 0)) {
 994                                         *pref = ref->next;
 995                                         delete_xattr_ref(c, ref);
 996                                         goto retry;
 997                                 } else if (unlikely(rc < 0))
 998                                         goto out;
 999                         }
1000                 }
1001                 xhandle = xprefix_to_handler(xd->xprefix);
1002                 if (!xhandle || (xhandle->list && !xhandle->list(dentry)))
1003                         continue;
1004                 prefix = xhandle->prefix ?: xhandle->name;
1005                 prefix_len = strlen(prefix);
1006                 rc = prefix_len + xd->name_len + 1;
1007 
1008                 if (buffer) {
1009                         if (rc > size - len) {
1010                                 rc = -ERANGE;
1011                                 goto out;
1012                         }
1013                         memcpy(buffer, prefix, prefix_len);
1014                         buffer += prefix_len;
1015                         memcpy(buffer, xd->xname, xd->name_len);
1016                         buffer += xd->name_len;
1017                         *buffer++ = 0;
1018                 }
1019                 len += rc;
1020         }
1021         rc = len;
1022  out:
1023         if (!retry) {
1024                 up_read(&c->xattr_sem);
1025         } else {
1026                 up_write(&c->xattr_sem);
1027         }
1028         return rc;
1029 }
1030 
1031 int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1032                       char *buffer, size_t size)
1033 {
1034         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1035         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1036         struct jffs2_inode_cache *ic = f->inocache;
1037         struct jffs2_xattr_datum *xd;
1038         struct jffs2_xattr_ref *ref, **pref;
1039         int rc, retry = 0;
1040 
1041         rc = check_xattr_ref_inode(c, ic);
1042         if (unlikely(rc))
1043                 return rc;
1044 
1045         down_read(&c->xattr_sem);
1046  retry:
1047         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1048                 BUG_ON(ref->ic!=ic);
1049 
1050                 xd = ref->xd;
1051                 if (xd->xprefix != xprefix)
1052                         continue;
1053                 if (!xd->xname) {
1054                         /* xdatum is unchached */
1055                         if (!retry) {
1056                                 retry = 1;
1057                                 up_read(&c->xattr_sem);
1058                                 down_write(&c->xattr_sem);
1059                                 goto retry;
1060                         } else {
1061                                 rc = load_xattr_datum(c, xd);
1062                                 if (unlikely(rc > 0)) {
1063                                         *pref = ref->next;
1064                                         delete_xattr_ref(c, ref);
1065                                         goto retry;
1066                                 } else if (unlikely(rc < 0)) {
1067                                         goto out;
1068                                 }
1069                         }
1070                 }
1071                 if (!strcmp(xname, xd->xname)) {
1072                         rc = xd->value_len;
1073                         if (buffer) {
1074                                 if (size < rc) {
1075                                         rc = -ERANGE;
1076                                 } else {
1077                                         memcpy(buffer, xd->xvalue, rc);
1078                                 }
1079                         }
1080                         goto out;
1081                 }
1082         }
1083         rc = -ENODATA;
1084  out:
1085         if (!retry) {
1086                 up_read(&c->xattr_sem);
1087         } else {
1088                 up_write(&c->xattr_sem);
1089         }
1090         return rc;
1091 }
1092 
1093 int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1094                       const char *buffer, size_t size, int flags)
1095 {
1096         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1097         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1098         struct jffs2_inode_cache *ic = f->inocache;
1099         struct jffs2_xattr_datum *xd;
1100         struct jffs2_xattr_ref *ref, *newref, **pref;
1101         uint32_t length, request;
1102         int rc;
1103 
1104         rc = check_xattr_ref_inode(c, ic);
1105         if (unlikely(rc))
1106                 return rc;
1107 
1108         request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1109         rc = jffs2_reserve_space(c, request, &length,
1110                                  ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1111         if (rc) {
1112                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1113                 return rc;
1114         }
1115 
1116         /* Find existing xattr */
1117         down_write(&c->xattr_sem);
1118  retry:
1119         for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1120                 xd = ref->xd;
1121                 if (xd->xprefix != xprefix)
1122                         continue;
1123                 if (!xd->xname) {
1124                         rc = load_xattr_datum(c, xd);
1125                         if (unlikely(rc > 0)) {
1126                                 *pref = ref->next;
1127                                 delete_xattr_ref(c, ref);
1128                                 goto retry;
1129                         } else if (unlikely(rc < 0))
1130                                 goto out;
1131                 }
1132                 if (!strcmp(xd->xname, xname)) {
1133                         if (flags & XATTR_CREATE) {
1134                                 rc = -EEXIST;
1135                                 goto out;
1136                         }
1137                         if (!buffer) {
1138                                 ref->ino = ic->ino;
1139                                 ref->xid = xd->xid;
1140                                 ref->xseqno |= XREF_DELETE_MARKER;
1141                                 rc = save_xattr_ref(c, ref);
1142                                 if (!rc) {
1143                                         *pref = ref->next;
1144                                         spin_lock(&c->erase_completion_lock);
1145                                         ref->next = c->xref_dead_list;
1146                                         c->xref_dead_list = ref;
1147                                         spin_unlock(&c->erase_completion_lock);
1148                                         unrefer_xattr_datum(c, xd);
1149                                 } else {
1150                                         ref->ic = ic;
1151                                         ref->xd = xd;
1152                                         ref->xseqno &= ~XREF_DELETE_MARKER;
1153                                 }
1154                                 goto out;
1155                         }
1156                         goto found;
1157                 }
1158         }
1159         /* not found */
1160         if (flags & XATTR_REPLACE) {
1161                 rc = -ENODATA;
1162                 goto out;
1163         }
1164         if (!buffer) {
1165                 rc = -ENODATA;
1166                 goto out;
1167         }
1168  found:
1169         xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1170         if (IS_ERR(xd)) {
1171                 rc = PTR_ERR(xd);
1172                 goto out;
1173         }
1174         up_write(&c->xattr_sem);
1175         jffs2_complete_reservation(c);
1176 
1177         /* create xattr_ref */
1178         request = PAD(sizeof(struct jffs2_raw_xref));
1179         rc = jffs2_reserve_space(c, request, &length,
1180                                  ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1181         down_write(&c->xattr_sem);
1182         if (rc) {
1183                 JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1184                 unrefer_xattr_datum(c, xd);
1185                 up_write(&c->xattr_sem);
1186                 return rc;
1187         }
1188         if (ref)
1189                 *pref = ref->next;
1190         newref = create_xattr_ref(c, ic, xd);
1191         if (IS_ERR(newref)) {
1192                 if (ref) {
1193                         ref->next = ic->xref;
1194                         ic->xref = ref;
1195                 }
1196                 rc = PTR_ERR(newref);
1197                 unrefer_xattr_datum(c, xd);
1198         } else if (ref) {
1199                 delete_xattr_ref(c, ref);
1200         }
1201  out:
1202         up_write(&c->xattr_sem);
1203         jffs2_complete_reservation(c);
1204         return rc;
1205 }
1206 
1207 /* -------- garbage collector functions -------------
1208  * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1209  *   is used to move xdatum into new node.
1210  * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1211  *   is used to move xref into new node.
1212  * jffs2_verify_xattr(c)
1213  *   is used to call do_verify_xattr_datum() before garbage collecting.
1214  * jffs2_release_xattr_datum(c, xd)
1215  *   is used to release an in-memory object of xdatum.
1216  * jffs2_release_xattr_ref(c, ref)
1217  *   is used to release an in-memory object of xref.
1218  * -------------------------------------------------- */
1219 int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1220                                       struct jffs2_raw_node_ref *raw)
1221 {
1222         uint32_t totlen, length, old_ofs;
1223         int rc = 0;
1224 
1225         down_write(&c->xattr_sem);
1226         if (xd->node != raw)
1227                 goto out;
1228         if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1229                 goto out;
1230 
1231         rc = load_xattr_datum(c, xd);
1232         if (unlikely(rc)) {
1233                 rc = (rc > 0) ? 0 : rc;
1234                 goto out;
1235         }
1236         old_ofs = ref_offset(xd->node);
1237         totlen = PAD(sizeof(struct jffs2_raw_xattr)
1238                         + xd->name_len + 1 + xd->value_len);
1239         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1240         if (rc) {
1241                 JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1242                 goto out;
1243         }
1244         rc = save_xattr_datum(c, xd);
1245         if (!rc)
1246                 dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1247                           xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1248  out:
1249         if (!rc)
1250                 jffs2_mark_node_obsolete(c, raw);
1251         up_write(&c->xattr_sem);
1252         return rc;
1253 }
1254 
1255 int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1256                                     struct jffs2_raw_node_ref *raw)
1257 {
1258         uint32_t totlen, length, old_ofs;
1259         int rc = 0;
1260 
1261         down_write(&c->xattr_sem);
1262         BUG_ON(!ref->node);
1263 
1264         if (ref->node != raw)
1265                 goto out;
1266         if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1267                 goto out;
1268 
1269         old_ofs = ref_offset(ref->node);
1270         totlen = ref_totlen(c, c->gcblock, ref->node);
1271 
1272         rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1273         if (rc) {
1274                 JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1275                               __func__, rc, totlen);
1276                 goto out;
1277         }
1278         rc = save_xattr_ref(c, ref);
1279         if (!rc)
1280                 dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1281                           ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1282  out:
1283         if (!rc)
1284                 jffs2_mark_node_obsolete(c, raw);
1285         up_write(&c->xattr_sem);
1286         return rc;
1287 }
1288 
1289 int jffs2_verify_xattr(struct jffs2_sb_info *c)
1290 {
1291         struct jffs2_xattr_datum *xd, *_xd;
1292         struct jffs2_eraseblock *jeb;
1293         struct jffs2_raw_node_ref *raw;
1294         uint32_t totlen;
1295         int rc;
1296 
1297         down_write(&c->xattr_sem);
1298         list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1299                 rc = do_verify_xattr_datum(c, xd);
1300                 if (rc < 0)
1301                         continue;
1302                 list_del_init(&xd->xindex);
1303                 spin_lock(&c->erase_completion_lock);
1304                 for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1305                         if (ref_flags(raw) != REF_UNCHECKED)
1306                                 continue;
1307                         jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1308                         totlen = PAD(ref_totlen(c, jeb, raw));
1309                         c->unchecked_size -= totlen; c->used_size += totlen;
1310                         jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1311                         raw->flash_offset = ref_offset(raw)
1312                                 | ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1313                 }
1314                 if (xd->flags & JFFS2_XFLAGS_DEAD)
1315                         list_add(&xd->xindex, &c->xattr_dead_list);
1316                 spin_unlock(&c->erase_completion_lock);
1317         }
1318         up_write(&c->xattr_sem);
1319         return list_empty(&c->xattr_unchecked) ? 1 : 0;
1320 }
1321 
1322 void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1323 {
1324         /* must be called under spin_lock(&c->erase_completion_lock) */
1325         if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1326                 return;
1327 
1328         list_del(&xd->xindex);
1329         jffs2_free_xattr_datum(xd);
1330 }
1331 
1332 void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1333 {
1334         /* must be called under spin_lock(&c->erase_completion_lock) */
1335         struct jffs2_xattr_ref *tmp, **ptmp;
1336 
1337         if (ref->node != (void *)ref)
1338                 return;
1339 
1340         for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1341                 if (ref == tmp) {
1342                         *ptmp = tmp->next;
1343                         break;
1344                 }
1345         }
1346         jffs2_free_xattr_ref(ref);
1347 }
/* [<][>][^][v][top][bottom][index][help] */
root/fs/jffs2/xattr.c

DEFINITIONS
