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   1/*
   2 * JFFS2 -- Journalling Flash File System, Version 2.
   3 *
   4 * Copyright © 2006  NEC Corporation
   5 *
   6 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
   7 *
   8 * For licensing information, see the file 'LICENCE' in this directory.
   9 *
  10 */
  11
  12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14#define JFFS2_XATTR_IS_CORRUPTED	1
  15
  16#include <linux/kernel.h>
  17#include <linux/slab.h>
  18#include <linux/fs.h>
  19#include <linux/time.h>
  20#include <linux/pagemap.h>
  21#include <linux/highmem.h>
  22#include <linux/crc32.h>
  23#include <linux/jffs2.h>
  24#include <linux/xattr.h>
  25#include <linux/mtd/mtd.h>
  26#include "nodelist.h"
  27/* -------- xdatum related functions ----------------
  28 * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
  29 *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
  30 *   the index of the xattr name/value pair cache (c->xattrindex).
  31 * is_xattr_datum_unchecked(c, xd)
  32 *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
  33 *   unchecked, it returns 0.
  34 * unload_xattr_datum(c, xd)
  35 *   is used to release xattr name/value pair and detach from c->xattrindex.
  36 * reclaim_xattr_datum(c)
  37 *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
  38 *   memory usage by cache is over c->xdatum_mem_threshold. Currently, this threshold
  39 *   is hard coded as 32KiB.
  40 * do_verify_xattr_datum(c, xd)
  41 *   is used to load the xdatum informations without name/value pair from the medium.
  42 *   It's necessary once, because those informations are not collected during mounting
  43 *   process when EBS is enabled.
  44 *   0 will be returned, if success. An negative return value means recoverable error, and
  45 *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
  46 *   and xref when it returned positive value.
  47 * do_load_xattr_datum(c, xd)
  48 *   is used to load name/value pair from the medium.
  49 *   The meanings of return value is same as do_verify_xattr_datum().
  50 * load_xattr_datum(c, xd)
  51 *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
  52 *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
  53 *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
  54 * save_xattr_datum(c, xd)
  55 *   is used to write xdatum to medium. xd->version will be incremented.
  56 * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
  57 *   is used to create new xdatum and write to medium.
  58 * unrefer_xattr_datum(c, xd)
  59 *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
  60 *   is set on xd->flags and chained xattr_dead_list or release it immediately.
  61 *   In the first case, the garbage collector release it later.
  62 * -------------------------------------------------- */
  63static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
  64{
  65	int name_len = strlen(xname);
  66
  67	return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
  68}
  69
  70static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  71{
  72	struct jffs2_raw_node_ref *raw;
  73	int rc = 0;
  74
  75	spin_lock(&c->erase_completion_lock);
  76	for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
  77		if (ref_flags(raw) == REF_UNCHECKED) {
  78			rc = 1;
  79			break;
  80		}
  81	}
  82	spin_unlock(&c->erase_completion_lock);
  83	return rc;
  84}
  85
  86static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
  87{
  88	/* must be called under down_write(xattr_sem) */
  89	D1(dbg_xattr("%s: xid=%u, version=%u\n", __func__, xd->xid, xd->version));
  90	if (xd->xname) {
  91		c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
  92		kfree(xd->xname);
  93	}
  94
  95	list_del_init(&xd->xindex);
  96	xd->hashkey = 0;
  97	xd->xname = NULL;
  98	xd->xvalue = NULL;
  99}
 100
 101static void reclaim_xattr_datum(struct jffs2_sb_info *c)
 102{
 103	/* must be called under down_write(xattr_sem) */
 104	struct jffs2_xattr_datum *xd, *_xd;
 105	uint32_t target, before;
 106	static int index = 0;
 107	int count;
 108
 109	if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
 110		return;
 111
 112	before = c->xdatum_mem_usage;
 113	target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
 114	for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
 115		list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
 116			if (xd->flags & JFFS2_XFLAGS_HOT) {
 117				xd->flags &= ~JFFS2_XFLAGS_HOT;
 118			} else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
 119				unload_xattr_datum(c, xd);
 120			}
 121			if (c->xdatum_mem_usage <= target)
 122				goto out;
 123		}
 124		index = (index+1) % XATTRINDEX_HASHSIZE;
 125	}
 126 out:
 127	JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
 128		     before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
 129}
 130
 131static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 132{
 133	/* must be called under down_write(xattr_sem) */
 134	struct jffs2_eraseblock *jeb;
 135	struct jffs2_raw_node_ref *raw;
 136	struct jffs2_raw_xattr rx;
 137	size_t readlen;
 138	uint32_t crc, offset, totlen;
 139	int rc;
 140
 141	spin_lock(&c->erase_completion_lock);
 142	offset = ref_offset(xd->node);
 143	if (ref_flags(xd->node) == REF_PRISTINE)
 144		goto complete;
 145	spin_unlock(&c->erase_completion_lock);
 146
 147	rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
 148	if (rc || readlen != sizeof(rx)) {
 149		JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
 150			      rc, sizeof(rx), readlen, offset);
 151		return rc ? rc : -EIO;
 152	}
 153	crc = crc32(0, &rx, sizeof(rx) - 4);
 154	if (crc != je32_to_cpu(rx.node_crc)) {
 155		JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 156			    offset, je32_to_cpu(rx.hdr_crc), crc);
 157		xd->flags |= JFFS2_XFLAGS_INVALID;
 158		return JFFS2_XATTR_IS_CORRUPTED;
 159	}
 160	totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
 161	if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
 162	    || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
 163	    || je32_to_cpu(rx.totlen) != totlen
 164	    || je32_to_cpu(rx.xid) != xd->xid
 165	    || je32_to_cpu(rx.version) != xd->version) {
 166		JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
 167			    "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
 168			    offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
 169			    je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
 170			    je32_to_cpu(rx.totlen), totlen,
 171			    je32_to_cpu(rx.xid), xd->xid,
 172			    je32_to_cpu(rx.version), xd->version);
 173		xd->flags |= JFFS2_XFLAGS_INVALID;
 174		return JFFS2_XATTR_IS_CORRUPTED;
 175	}
 176	xd->xprefix = rx.xprefix;
 177	xd->name_len = rx.name_len;
 178	xd->value_len = je16_to_cpu(rx.value_len);
 179	xd->data_crc = je32_to_cpu(rx.data_crc);
 180
 181	spin_lock(&c->erase_completion_lock);
 182 complete:
 183	for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
 184		jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 185		totlen = PAD(ref_totlen(c, jeb, raw));
 186		if (ref_flags(raw) == REF_UNCHECKED) {
 187			c->unchecked_size -= totlen; c->used_size += totlen;
 188			jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 189		}
 190		raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
 191	}
 192	spin_unlock(&c->erase_completion_lock);
 193
 194	/* unchecked xdatum is chained with c->xattr_unchecked */
 195	list_del_init(&xd->xindex);
 196
 197	dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
 198		  xd->xid, xd->version);
 199
 200	return 0;
 201}
 202
 203static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 204{
 205	/* must be called under down_write(xattr_sem) */
 206	char *data;
 207	size_t readlen;
 208	uint32_t crc, length;
 209	int i, ret, retry = 0;
 210
 211	BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
 212	BUG_ON(!list_empty(&xd->xindex));
 213 retry:
 214	length = xd->name_len + 1 + xd->value_len;
 215	data = kmalloc(length, GFP_KERNEL);
 216	if (!data)
 217		return -ENOMEM;
 218
 219	ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
 220			       length, &readlen, data);
 221
 222	if (ret || length!=readlen) {
 223		JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
 224			      ret, length, readlen, ref_offset(xd->node));
 225		kfree(data);
 226		return ret ? ret : -EIO;
 227	}
 228
 229	data[xd->name_len] = '\0';
 230	crc = crc32(0, data, length);
 231	if (crc != xd->data_crc) {
 232		JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XATTR)"
 233			      " at %#08x, read: 0x%08x calculated: 0x%08x\n",
 234			      ref_offset(xd->node), xd->data_crc, crc);
 235		kfree(data);
 236		xd->flags |= JFFS2_XFLAGS_INVALID;
 237		return JFFS2_XATTR_IS_CORRUPTED;
 238	}
 239
 240	xd->flags |= JFFS2_XFLAGS_HOT;
 241	xd->xname = data;
 242	xd->xvalue = data + xd->name_len+1;
 243
 244	c->xdatum_mem_usage += length;
 245
 246	xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
 247	i = xd->hashkey % XATTRINDEX_HASHSIZE;
 248	list_add(&xd->xindex, &c->xattrindex[i]);
 249	if (!retry) {
 250		retry = 1;
 251		reclaim_xattr_datum(c);
 252		if (!xd->xname)
 253			goto retry;
 254	}
 255
 256	dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
 257		  xd->xid, xd->xprefix, xd->xname);
 258
 259	return 0;
 260}
 261
 262static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 263{
 264	/* must be called under down_write(xattr_sem);
 265	 * rc < 0 : recoverable error, try again
 266	 * rc = 0 : success
 267	 * rc > 0 : Unrecoverable error, this node should be deleted.
 268	 */
 269	int rc = 0;
 270
 271	BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
 272	if (xd->xname)
 273		return 0;
 274	if (xd->flags & JFFS2_XFLAGS_INVALID)
 275		return JFFS2_XATTR_IS_CORRUPTED;
 276	if (unlikely(is_xattr_datum_unchecked(c, xd)))
 277		rc = do_verify_xattr_datum(c, xd);
 278	if (!rc)
 279		rc = do_load_xattr_datum(c, xd);
 280	return rc;
 281}
 282
 283static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 284{
 285	/* must be called under down_write(xattr_sem) */
 286	struct jffs2_raw_xattr rx;
 287	struct kvec vecs[2];
 288	size_t length;
 289	int rc, totlen;
 290	uint32_t phys_ofs = write_ofs(c);
 291
 292	BUG_ON(!xd->xname);
 293	BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
 294
 295	vecs[0].iov_base = &rx;
 296	vecs[0].iov_len = sizeof(rx);
 297	vecs[1].iov_base = xd->xname;
 298	vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
 299	totlen = vecs[0].iov_len + vecs[1].iov_len;
 300
 301	/* Setup raw-xattr */
 302	memset(&rx, 0, sizeof(rx));
 303	rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 304	rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
 305	rx.totlen = cpu_to_je32(PAD(totlen));
 306	rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));
 307
 308	rx.xid = cpu_to_je32(xd->xid);
 309	rx.version = cpu_to_je32(++xd->version);
 310	rx.xprefix = xd->xprefix;
 311	rx.name_len = xd->name_len;
 312	rx.value_len = cpu_to_je16(xd->value_len);
 313	rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
 314	rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
 315
 316	rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
 317	if (rc || totlen != length) {
 318		JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
 319			      rc, totlen, length, phys_ofs);
 320		rc = rc ? rc : -EIO;
 321		if (length)
 322			jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
 323
 324		return rc;
 325	}
 326	/* success */
 327	jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
 328
 329	dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
 330		  xd->xid, xd->version, xd->xprefix, xd->xname);
 331
 332	return 0;
 333}
 334
 335static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
 336						    int xprefix, const char *xname,
 337						    const char *xvalue, int xsize)
 338{
 339	/* must be called under down_write(xattr_sem) */
 340	struct jffs2_xattr_datum *xd;
 341	uint32_t hashkey, name_len;
 342	char *data;
 343	int i, rc;
 344
 345	/* Search xattr_datum has same xname/xvalue by index */
 346	hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
 347	i = hashkey % XATTRINDEX_HASHSIZE;
 348	list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 349		if (xd->hashkey==hashkey
 350		    && xd->xprefix==xprefix
 351		    && xd->value_len==xsize
 352		    && !strcmp(xd->xname, xname)
 353		    && !memcmp(xd->xvalue, xvalue, xsize)) {
 354			atomic_inc(&xd->refcnt);
 355			return xd;
 356		}
 357	}
 358
 359	/* Not found, Create NEW XATTR-Cache */
 360	name_len = strlen(xname);
 361
 362	xd = jffs2_alloc_xattr_datum();
 363	if (!xd)
 364		return ERR_PTR(-ENOMEM);
 365
 366	data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
 367	if (!data) {
 368		jffs2_free_xattr_datum(xd);
 369		return ERR_PTR(-ENOMEM);
 370	}
 371	strcpy(data, xname);
 372	memcpy(data + name_len + 1, xvalue, xsize);
 373
 374	atomic_set(&xd->refcnt, 1);
 375	xd->xid = ++c->highest_xid;
 376	xd->flags |= JFFS2_XFLAGS_HOT;
 377	xd->xprefix = xprefix;
 378
 379	xd->hashkey = hashkey;
 380	xd->xname = data;
 381	xd->xvalue = data + name_len + 1;
 382	xd->name_len = name_len;
 383	xd->value_len = xsize;
 384	xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);
 385
 386	rc = save_xattr_datum(c, xd);
 387	if (rc) {
 388		kfree(xd->xname);
 389		jffs2_free_xattr_datum(xd);
 390		return ERR_PTR(rc);
 391	}
 392
 393	/* Insert Hash Index */
 394	i = hashkey % XATTRINDEX_HASHSIZE;
 395	list_add(&xd->xindex, &c->xattrindex[i]);
 396
 397	c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
 398	reclaim_xattr_datum(c);
 399
 400	return xd;
 401}
 402
 403static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
 404{
 405	/* must be called under down_write(xattr_sem) */
 406	if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
 407		unload_xattr_datum(c, xd);
 408		xd->flags |= JFFS2_XFLAGS_DEAD;
 409		if (xd->node == (void *)xd) {
 410			BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
 411			jffs2_free_xattr_datum(xd);
 412		} else {
 413			list_add(&xd->xindex, &c->xattr_dead_list);
 414		}
 415		spin_unlock(&c->erase_completion_lock);
 416
 417		dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
 418			  xd->xid, xd->version);
 419	}
 420}
 421
 422/* -------- xref related functions ------------------
 423 * verify_xattr_ref(c, ref)
 424 *   is used to load xref information from medium. Because summary data does not
 425 *   contain xid/ino, it's necessary to verify once while mounting process.
 426 * save_xattr_ref(c, ref)
 427 *   is used to write xref to medium. If delete marker is marked, it write
 428 *   a delete marker of xref into medium.
 429 * create_xattr_ref(c, ic, xd)
 430 *   is used to create a new xref and write to medium.
 431 * delete_xattr_ref(c, ref)
 432 *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 433 *   and allows GC to reclaim those physical nodes.
 434 * jffs2_xattr_delete_inode(c, ic)
 435 *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 436 * jffs2_xattr_free_inode(c, ic)
 437 *   is called to release xattr related objects when unmounting. 
 438 * check_xattr_ref_inode(c, ic)
 439 *   is used to confirm inode does not have duplicate xattr name/value pair.
 440 * jffs2_xattr_do_crccheck_inode(c, ic)
 441 *   is used to force xattr data integrity check during the initial gc scan.
 442 * -------------------------------------------------- */
 443static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 444{
 445	struct jffs2_eraseblock *jeb;
 446	struct jffs2_raw_node_ref *raw;
 447	struct jffs2_raw_xref rr;
 448	size_t readlen;
 449	uint32_t crc, offset, totlen;
 450	int rc;
 451
 452	spin_lock(&c->erase_completion_lock);
 453	if (ref_flags(ref->node) != REF_UNCHECKED)
 454		goto complete;
 455	offset = ref_offset(ref->node);
 456	spin_unlock(&c->erase_completion_lock);
 457
 458	rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
 459	if (rc || sizeof(rr) != readlen) {
 460		JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
 461			      rc, sizeof(rr), readlen, offset);
 462		return rc ? rc : -EIO;
 463	}
 464	/* obsolete node */
 465	crc = crc32(0, &rr, sizeof(rr) - 4);
 466	if (crc != je32_to_cpu(rr.node_crc)) {
 467		JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 468			    offset, je32_to_cpu(rr.node_crc), crc);
 469		return JFFS2_XATTR_IS_CORRUPTED;
 470	}
 471	if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
 472	    || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
 473	    || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
 474		JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
 475			    "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
 476			    offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
 477			    je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
 478			    je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
 479		return JFFS2_XATTR_IS_CORRUPTED;
 480	}
 481	ref->ino = je32_to_cpu(rr.ino);
 482	ref->xid = je32_to_cpu(rr.xid);
 483	ref->xseqno = je32_to_cpu(rr.xseqno);
 484	if (ref->xseqno > c->highest_xseqno)
 485		c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 486
 487	spin_lock(&c->erase_completion_lock);
 488 complete:
 489	for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
 490		jeb = &c->blocks[ref_offset(raw) / c->sector_size];
 491		totlen = PAD(ref_totlen(c, jeb, raw));
 492		if (ref_flags(raw) == REF_UNCHECKED) {
 493			c->unchecked_size -= totlen; c->used_size += totlen;
 494			jeb->unchecked_size -= totlen; jeb->used_size += totlen;
 495		}
 496		raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
 497	}
 498	spin_unlock(&c->erase_completion_lock);
 499
 500	dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
 501		  ref->ino, ref->xid, ref_offset(ref->node));
 502	return 0;
 503}
 504
 505static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 506{
 507	/* must be called under down_write(xattr_sem) */
 508	struct jffs2_raw_xref rr;
 509	size_t length;
 510	uint32_t xseqno, phys_ofs = write_ofs(c);
 511	int ret;
 512
 513	rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 514	rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
 515	rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
 516	rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));
 517
 518	xseqno = (c->highest_xseqno += 2);
 519	if (is_xattr_ref_dead(ref)) {
 520		xseqno |= XREF_DELETE_MARKER;
 521		rr.ino = cpu_to_je32(ref->ino);
 522		rr.xid = cpu_to_je32(ref->xid);
 523	} else {
 524		rr.ino = cpu_to_je32(ref->ic->ino);
 525		rr.xid = cpu_to_je32(ref->xd->xid);
 526	}
 527	rr.xseqno = cpu_to_je32(xseqno);
 528	rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));
 529
 530	ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
 531	if (ret || sizeof(rr) != length) {
 532		JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
 533			      ret, sizeof(rr), length, phys_ofs);
 534		ret = ret ? ret : -EIO;
 535		if (length)
 536			jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
 537
 538		return ret;
 539	}
 540	/* success */
 541	ref->xseqno = xseqno;
 542	jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
 543
 544	dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);
 545
 546	return 0;
 547}
 548
 549static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
 550						struct jffs2_xattr_datum *xd)
 551{
 552	/* must be called under down_write(xattr_sem) */
 553	struct jffs2_xattr_ref *ref;
 554	int ret;
 555
 556	ref = jffs2_alloc_xattr_ref();
 557	if (!ref)
 558		return ERR_PTR(-ENOMEM);
 559	ref->ic = ic;
 560	ref->xd = xd;
 561
 562	ret = save_xattr_ref(c, ref);
 563	if (ret) {
 564		jffs2_free_xattr_ref(ref);
 565		return ERR_PTR(ret);
 566	}
 567
 568	/* Chain to inode */
 569	ref->next = ic->xref;
 570	ic->xref = ref;
 571
 572	return ref; /* success */
 573}
 574
 575static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
 576{
 577	/* must be called under down_write(xattr_sem) */
 578	struct jffs2_xattr_datum *xd;
 579
 580	xd = ref->xd;
 581	ref->xseqno |= XREF_DELETE_MARKER;
 582	ref->ino = ref->ic->ino;
 583	ref->xid = ref->xd->xid;
 584	spin_lock(&c->erase_completion_lock);
 585	ref->next = c->xref_dead_list;
 586	c->xref_dead_list = ref;
 587	spin_unlock(&c->erase_completion_lock);
 588
 589	dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
 590		  ref->ino, ref->xid, ref->xseqno);
 591
 592	unrefer_xattr_datum(c, xd);
 593}
 594
 595void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 596{
 597	/* It's called from jffs2_evict_inode() on inode removing.
 598	   When an inode with XATTR is removed, those XATTRs must be removed. */
 599	struct jffs2_xattr_ref *ref, *_ref;
 600
 601	if (!ic || ic->pino_nlink > 0)
 602		return;
 603
 604	down_write(&c->xattr_sem);
 605	for (ref = ic->xref; ref; ref = _ref) {
 606		_ref = ref->next;
 607		delete_xattr_ref(c, ref);
 608	}
 609	ic->xref = NULL;
 610	up_write(&c->xattr_sem);
 611}
 612
 613void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 614{
 615	/* It's called from jffs2_free_ino_caches() until unmounting FS. */
 616	struct jffs2_xattr_datum *xd;
 617	struct jffs2_xattr_ref *ref, *_ref;
 618
 619	down_write(&c->xattr_sem);
 620	for (ref = ic->xref; ref; ref = _ref) {
 621		_ref = ref->next;
 622		xd = ref->xd;
 623		if (atomic_dec_and_test(&xd->refcnt)) {
 624			unload_xattr_datum(c, xd);
 625			jffs2_free_xattr_datum(xd);
 626		}
 627		jffs2_free_xattr_ref(ref);
 628	}
 629	ic->xref = NULL;
 630	up_write(&c->xattr_sem);
 631}
 632
 633static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 634{
 635	/* success of check_xattr_ref_inode() means that inode (ic) dose not have
 636	 * duplicate name/value pairs. If duplicate name/value pair would be found,
 637	 * one will be removed.
 638	 */
 639	struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
 640	int rc = 0;
 641
 642	if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
 643		return 0;
 644	down_write(&c->xattr_sem);
 645 retry:
 646	rc = 0;
 647	for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 648		if (!ref->xd->xname) {
 649			rc = load_xattr_datum(c, ref->xd);
 650			if (unlikely(rc > 0)) {
 651				*pref = ref->next;
 652				delete_xattr_ref(c, ref);
 653				goto retry;
 654			} else if (unlikely(rc < 0))
 655				goto out;
 656		}
 657		for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
 658			if (!cmp->xd->xname) {
 659				ref->xd->flags |= JFFS2_XFLAGS_BIND;
 660				rc = load_xattr_datum(c, cmp->xd);
 661				ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
 662				if (unlikely(rc > 0)) {
 663					*pcmp = cmp->next;
 664					delete_xattr_ref(c, cmp);
 665					goto retry;
 666				} else if (unlikely(rc < 0))
 667					goto out;
 668			}
 669			if (ref->xd->xprefix == cmp->xd->xprefix
 670			    && !strcmp(ref->xd->xname, cmp->xd->xname)) {
 671				if (ref->xseqno > cmp->xseqno) {
 672					*pcmp = cmp->next;
 673					delete_xattr_ref(c, cmp);
 674				} else {
 675					*pref = ref->next;
 676					delete_xattr_ref(c, ref);
 677				}
 678				goto retry;
 679			}
 680		}
 681	}
 682	ic->flags |= INO_FLAGS_XATTR_CHECKED;
 683 out:
 684	up_write(&c->xattr_sem);
 685
 686	return rc;
 687}
 688
 689void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
 690{
 691	check_xattr_ref_inode(c, ic);
 692}
 693
 694/* -------- xattr subsystem functions ---------------
 695 * jffs2_init_xattr_subsystem(c)
 696 *   is used to initialize semaphore and list_head, and some variables.
 697 * jffs2_find_xattr_datum(c, xid)
 698 *   is used to lookup xdatum while scanning process.
 699 * jffs2_clear_xattr_subsystem(c)
 700 *   is used to release any xattr related objects.
 701 * jffs2_build_xattr_subsystem(c)
 702 *   is used to associate xdatum and xref while super block building process.
 703 * jffs2_setup_xattr_datum(c, xid, version)
 704 *   is used to insert xdatum while scanning process.
 705 * -------------------------------------------------- */
 706void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
 707{
 708	int i;
 709
 710	for (i=0; i < XATTRINDEX_HASHSIZE; i++)
 711		INIT_LIST_HEAD(&c->xattrindex[i]);
 712	INIT_LIST_HEAD(&c->xattr_unchecked);
 713	INIT_LIST_HEAD(&c->xattr_dead_list);
 714	c->xref_dead_list = NULL;
 715	c->xref_temp = NULL;
 716
 717	init_rwsem(&c->xattr_sem);
 718	c->highest_xid = 0;
 719	c->highest_xseqno = 0;
 720	c->xdatum_mem_usage = 0;
 721	c->xdatum_mem_threshold = 32 * 1024;	/* Default 32KB */
 722}
 723
 724static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
 725{
 726	struct jffs2_xattr_datum *xd;
 727	int i = xid % XATTRINDEX_HASHSIZE;
 728
 729	/* It's only used in scanning/building process. */
 730	BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));
 731
 732	list_for_each_entry(xd, &c->xattrindex[i], xindex) {
 733		if (xd->xid==xid)
 734			return xd;
 735	}
 736	return NULL;
 737}
 738
 739void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
 740{
 741	struct jffs2_xattr_datum *xd, *_xd;
 742	struct jffs2_xattr_ref *ref, *_ref;
 743	int i;
 744
 745	for (ref=c->xref_temp; ref; ref = _ref) {
 746		_ref = ref->next;
 747		jffs2_free_xattr_ref(ref);
 748	}
 749
 750	for (ref=c->xref_dead_list; ref; ref = _ref) {
 751		_ref = ref->next;
 752		jffs2_free_xattr_ref(ref);
 753	}
 754
 755	for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
 756		list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
 757			list_del(&xd->xindex);
 758			if (xd->xname)
 759				kfree(xd->xname);
 760			jffs2_free_xattr_datum(xd);
 761		}
 762	}
 763
 764	list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
 765		list_del(&xd->xindex);
 766		jffs2_free_xattr_datum(xd);
 767	}
 768	list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
 769		list_del(&xd->xindex);
 770		jffs2_free_xattr_datum(xd);
 771	}
 772}
 773
 774#define XREF_TMPHASH_SIZE	(128)
 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	&jffs2_acl_access_xattr_handler,
 925	&jffs2_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 = &jffs2_acl_access_xattr_handler;
 946		break;
 947	case JFFS2_XPREFIX_ACL_DEFAULT:
 948		ret = &jffs2_acl_default_xattr_handler;
 949		break;
 950#endif
 951	case JFFS2_XPREFIX_TRUSTED:
 952		ret = &jffs2_trusted_xattr_handler;
 953		break;
 954	default:
 955		ret = NULL;
 956		break;
 957	}
 958	return ret;
 959}
 960
 961ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 962{
 963	struct inode *inode = dentry->d_inode;
 964	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 965	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 966	struct jffs2_inode_cache *ic = f->inocache;
 967	struct jffs2_xattr_ref *ref, **pref;
 968	struct jffs2_xattr_datum *xd;
 969	const struct xattr_handler *xhandle;
 970	ssize_t len, rc;
 971	int retry = 0;
 972
 973	rc = check_xattr_ref_inode(c, ic);
 974	if (unlikely(rc))
 975		return rc;
 976
 977	down_read(&c->xattr_sem);
 978 retry:
 979	len = 0;
 980	for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
 981		BUG_ON(ref->ic != ic);
 982		xd = ref->xd;
 983		if (!xd->xname) {
 984			/* xdatum is unchached */
 985			if (!retry) {
 986				retry = 1;
 987				up_read(&c->xattr_sem);
 988				down_write(&c->xattr_sem);
 989				goto retry;
 990			} else {
 991				rc = load_xattr_datum(c, xd);
 992				if (unlikely(rc > 0)) {
 993					*pref = ref->next;
 994					delete_xattr_ref(c, ref);
 995					goto retry;
 996				} else if (unlikely(rc < 0))
 997					goto out;
 998			}
 999		}
1000		xhandle = xprefix_to_handler(xd->xprefix);
1001		if (!xhandle)
1002			continue;
1003		if (buffer) {
1004			rc = xhandle->list(dentry, buffer+len, size-len,
1005					   xd->xname, xd->name_len, xd->flags);
1006		} else {
1007			rc = xhandle->list(dentry, NULL, 0, xd->xname,
1008					   xd->name_len, xd->flags);
1009		}
1010		if (rc < 0)
1011			goto out;
1012		len += rc;
1013	}
1014	rc = len;
1015 out:
1016	if (!retry) {
1017		up_read(&c->xattr_sem);
1018	} else {
1019		up_write(&c->xattr_sem);
1020	}
1021	return rc;
1022}
1023
1024int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
1025		      char *buffer, size_t size)
1026{
1027	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1028	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1029	struct jffs2_inode_cache *ic = f->inocache;
1030	struct jffs2_xattr_datum *xd;
1031	struct jffs2_xattr_ref *ref, **pref;
1032	int rc, retry = 0;
1033
1034	rc = check_xattr_ref_inode(c, ic);
1035	if (unlikely(rc))
1036		return rc;
1037
1038	down_read(&c->xattr_sem);
1039 retry:
1040	for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1041		BUG_ON(ref->ic!=ic);
1042
1043		xd = ref->xd;
1044		if (xd->xprefix != xprefix)
1045			continue;
1046		if (!xd->xname) {
1047			/* xdatum is unchached */
1048			if (!retry) {
1049				retry = 1;
1050				up_read(&c->xattr_sem);
1051				down_write(&c->xattr_sem);
1052				goto retry;
1053			} else {
1054				rc = load_xattr_datum(c, xd);
1055				if (unlikely(rc > 0)) {
1056					*pref = ref->next;
1057					delete_xattr_ref(c, ref);
1058					goto retry;
1059				} else if (unlikely(rc < 0)) {
1060					goto out;
1061				}
1062			}
1063		}
1064		if (!strcmp(xname, xd->xname)) {
1065			rc = xd->value_len;
1066			if (buffer) {
1067				if (size < rc) {
1068					rc = -ERANGE;
1069				} else {
1070					memcpy(buffer, xd->xvalue, rc);
1071				}
1072			}
1073			goto out;
1074		}
1075	}
1076	rc = -ENODATA;
1077 out:
1078	if (!retry) {
1079		up_read(&c->xattr_sem);
1080	} else {
1081		up_write(&c->xattr_sem);
1082	}
1083	return rc;
1084}
1085
1086int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
1087		      const char *buffer, size_t size, int flags)
1088{
1089	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
1090	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
1091	struct jffs2_inode_cache *ic = f->inocache;
1092	struct jffs2_xattr_datum *xd;
1093	struct jffs2_xattr_ref *ref, *newref, **pref;
1094	uint32_t length, request;
1095	int rc;
1096
1097	rc = check_xattr_ref_inode(c, ic);
1098	if (unlikely(rc))
1099		return rc;
1100
1101	request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1102	rc = jffs2_reserve_space(c, request, &length,
1103				 ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
1104	if (rc) {
1105		JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1106		return rc;
1107	}
1108
1109	/* Find existing xattr */
1110	down_write(&c->xattr_sem);
1111 retry:
1112	for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1113		xd = ref->xd;
1114		if (xd->xprefix != xprefix)
1115			continue;
1116		if (!xd->xname) {
1117			rc = load_xattr_datum(c, xd);
1118			if (unlikely(rc > 0)) {
1119				*pref = ref->next;
1120				delete_xattr_ref(c, ref);
1121				goto retry;
1122			} else if (unlikely(rc < 0))
1123				goto out;
1124		}
1125		if (!strcmp(xd->xname, xname)) {
1126			if (flags & XATTR_CREATE) {
1127				rc = -EEXIST;
1128				goto out;
1129			}
1130			if (!buffer) {
1131				ref->ino = ic->ino;
1132				ref->xid = xd->xid;
1133				ref->xseqno |= XREF_DELETE_MARKER;
1134				rc = save_xattr_ref(c, ref);
1135				if (!rc) {
1136					*pref = ref->next;
1137					spin_lock(&c->erase_completion_lock);
1138					ref->next = c->xref_dead_list;
1139					c->xref_dead_list = ref;
1140					spin_unlock(&c->erase_completion_lock);
1141					unrefer_xattr_datum(c, xd);
1142				} else {
1143					ref->ic = ic;
1144					ref->xd = xd;
1145					ref->xseqno &= ~XREF_DELETE_MARKER;
1146				}
1147				goto out;
1148			}
1149			goto found;
1150		}
1151	}
1152	/* not found */
1153	if (flags & XATTR_REPLACE) {
1154		rc = -ENODATA;
1155		goto out;
1156	}
1157	if (!buffer) {
1158		rc = -ENODATA;
1159		goto out;
1160	}
1161 found:
1162	xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1163	if (IS_ERR(xd)) {
1164		rc = PTR_ERR(xd);
1165		goto out;
1166	}
1167	up_write(&c->xattr_sem);
1168	jffs2_complete_reservation(c);
1169
1170	/* create xattr_ref */
1171	request = PAD(sizeof(struct jffs2_raw_xref));
1172	rc = jffs2_reserve_space(c, request, &length,
1173				 ALLOC_NORMAL, JFFS2_SUMMARY_XREF_SIZE);
1174	down_write(&c->xattr_sem);
1175	if (rc) {
1176		JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1177		unrefer_xattr_datum(c, xd);
1178		up_write(&c->xattr_sem);
1179		return rc;
1180	}
1181	if (ref)
1182		*pref = ref->next;
1183	newref = create_xattr_ref(c, ic, xd);
1184	if (IS_ERR(newref)) {
1185		if (ref) {
1186			ref->next = ic->xref;
1187			ic->xref = ref;
1188		}
1189		rc = PTR_ERR(newref);
1190		unrefer_xattr_datum(c, xd);
1191	} else if (ref) {
1192		delete_xattr_ref(c, ref);
1193	}
1194 out:
1195	up_write(&c->xattr_sem);
1196	jffs2_complete_reservation(c);
1197	return rc;
1198}
1199
1200/* -------- garbage collector functions -------------
1201 * jffs2_garbage_collect_xattr_datum(c, xd, raw)
1202 *   is used to move xdatum into new node.
1203 * jffs2_garbage_collect_xattr_ref(c, ref, raw)
1204 *   is used to move xref into new node.
1205 * jffs2_verify_xattr(c)
1206 *   is used to call do_verify_xattr_datum() before garbage collecting.
1207 * jffs2_release_xattr_datum(c, xd)
1208 *   is used to release an in-memory object of xdatum.
1209 * jffs2_release_xattr_ref(c, ref)
1210 *   is used to release an in-memory object of xref.
1211 * -------------------------------------------------- */
1212int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
1213				      struct jffs2_raw_node_ref *raw)
1214{
1215	uint32_t totlen, length, old_ofs;
1216	int rc = 0;
1217
1218	down_write(&c->xattr_sem);
1219	if (xd->node != raw)
1220		goto out;
1221	if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1222		goto out;
1223
1224	rc = load_xattr_datum(c, xd);
1225	if (unlikely(rc)) {
1226		rc = (rc > 0) ? 0 : rc;
1227		goto out;
1228	}
1229	old_ofs = ref_offset(xd->node);
1230	totlen = PAD(sizeof(struct jffs2_raw_xattr)
1231			+ xd->name_len + 1 + xd->value_len);
1232	rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1233	if (rc) {
1234		JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1235		goto out;
1236	}
1237	rc = save_xattr_datum(c, xd);
1238	if (!rc)
1239		dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
1240			  xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1241 out:
1242	if (!rc)
1243		jffs2_mark_node_obsolete(c, raw);
1244	up_write(&c->xattr_sem);
1245	return rc;
1246}
1247
1248int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
1249				    struct jffs2_raw_node_ref *raw)
1250{
1251	uint32_t totlen, length, old_ofs;
1252	int rc = 0;
1253
1254	down_write(&c->xattr_sem);
1255	BUG_ON(!ref->node);
1256
1257	if (ref->node != raw)
1258		goto out;
1259	if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
1260		goto out;
1261
1262	old_ofs = ref_offset(ref->node);
1263	totlen = ref_totlen(c, c->gcblock, ref->node);
1264
1265	rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1266	if (rc) {
1267		JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1268			      __func__, rc, totlen);
1269		rc = rc ? rc : -EBADFD;
1270		goto out;
1271	}
1272	rc = save_xattr_ref(c, ref);
1273	if (!rc)
1274		dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
1275			  ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1276 out:
1277	if (!rc)
1278		jffs2_mark_node_obsolete(c, raw);
1279	up_write(&c->xattr_sem);
1280	return rc;
1281}
1282
1283int jffs2_verify_xattr(struct jffs2_sb_info *c)
1284{
1285	struct jffs2_xattr_datum *xd, *_xd;
1286	struct jffs2_eraseblock *jeb;
1287	struct jffs2_raw_node_ref *raw;
1288	uint32_t totlen;
1289	int rc;
1290
1291	down_write(&c->xattr_sem);
1292	list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
1293		rc = do_verify_xattr_datum(c, xd);
1294		if (rc < 0)
1295			continue;
1296		list_del_init(&xd->xindex);
1297		spin_lock(&c->erase_completion_lock);
1298		for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
1299			if (ref_flags(raw) != REF_UNCHECKED)
1300				continue;
1301			jeb = &c->blocks[ref_offset(raw) / c->sector_size];
1302			totlen = PAD(ref_totlen(c, jeb, raw));
1303			c->unchecked_size -= totlen; c->used_size += totlen;
1304			jeb->unchecked_size -= totlen; jeb->used_size += totlen;
1305			raw->flash_offset = ref_offset(raw)
1306				| ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1307		}
1308		if (xd->flags & JFFS2_XFLAGS_DEAD)
1309			list_add(&xd->xindex, &c->xattr_dead_list);
1310		spin_unlock(&c->erase_completion_lock);
1311	}
1312	up_write(&c->xattr_sem);
1313	return list_empty(&c->xattr_unchecked) ? 1 : 0;
1314}
1315
1316void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
1317{
1318	/* must be called under spin_lock(&c->erase_completion_lock) */
1319	if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1320		return;
1321
1322	list_del(&xd->xindex);
1323	jffs2_free_xattr_datum(xd);
1324}
1325
1326void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
1327{
1328	/* must be called under spin_lock(&c->erase_completion_lock) */
1329	struct jffs2_xattr_ref *tmp, **ptmp;
1330
1331	if (ref->node != (void *)ref)
1332		return;
1333
1334	for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
1335		if (ref == tmp) {
1336			*ptmp = tmp->next;
1337			break;
1338		}
1339	}
1340	jffs2_free_xattr_ref(ref);
1341}