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 * -------------------------------------------------- */
  64static 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
  71static 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
  87static 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
 102static 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
 132static 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
 204static 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
 263static 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
 284static 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
 336static 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
 404static 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 * -------------------------------------------------- */
 444static 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
 506static 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
 550static 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
 576static 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
 596void 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
 614void 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
 634static 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
 690void 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 * -------------------------------------------------- */
 707void 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
 725static 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
 740void 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)
 775void 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
 889struct 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 * -------------------------------------------------- */
 918const 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
 931static 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
 961ssize_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
1031int 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
1093int 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 * -------------------------------------------------- */
1219int 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
1255int 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
1289int 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
1322void 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
1332void 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}