xattr.c 38.2 KB
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/*
 * JFFS2 -- Journalling Flash File System, Version 2.
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 *
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 * Copyright © 2006  NEC Corporation
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 *
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 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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#define JFFS2_XATTR_IS_CORRUPTED	1

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#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/crc32.h>
#include <linux/jffs2.h>
#include <linux/xattr.h>
#include <linux/mtd/mtd.h>
#include "nodelist.h"
/* -------- xdatum related functions ----------------
 * xattr_datum_hashkey(xprefix, xname, xvalue, xsize)
 *   is used to calcurate xdatum hashkey. The reminder of hashkey into XATTRINDEX_HASHSIZE is
 *   the index of the xattr name/value pair cache (c->xattrindex).
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 * is_xattr_datum_unchecked(c, xd)
 *   returns 1, if xdatum contains any unchecked raw nodes. if all raw nodes are not
 *   unchecked, it returns 0.
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 * unload_xattr_datum(c, xd)
 *   is used to release xattr name/value pair and detach from c->xattrindex.
 * reclaim_xattr_datum(c)
 *   is used to reclaim xattr name/value pairs on the xattr name/value pair cache when
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 *   memory usage by cache is over c->xdatum_mem_threshold. Currently, this threshold
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 *   is hard coded as 32KiB.
 * do_verify_xattr_datum(c, xd)
 *   is used to load the xdatum informations without name/value pair from the medium.
 *   It's necessary once, because those informations are not collected during mounting
 *   process when EBS is enabled.
 *   0 will be returned, if success. An negative return value means recoverable error, and
 *   positive return value means unrecoverable error. Thus, caller must remove this xdatum
 *   and xref when it returned positive value.
 * do_load_xattr_datum(c, xd)
 *   is used to load name/value pair from the medium.
 *   The meanings of return value is same as do_verify_xattr_datum().
 * load_xattr_datum(c, xd)
 *   is used to be as a wrapper of do_verify_xattr_datum() and do_load_xattr_datum().
 *   If xd need to call do_verify_xattr_datum() at first, it's called before calling
 *   do_load_xattr_datum(). The meanings of return value is same as do_verify_xattr_datum().
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 * save_xattr_datum(c, xd)
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 *   is used to write xdatum to medium. xd->version will be incremented.
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 * create_xattr_datum(c, xprefix, xname, xvalue, xsize)
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 *   is used to create new xdatum and write to medium.
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 * unrefer_xattr_datum(c, xd)
 *   is used to delete a xdatum. When nobody refers this xdatum, JFFS2_XFLAGS_DEAD
 *   is set on xd->flags and chained xattr_dead_list or release it immediately.
 *   In the first case, the garbage collector release it later.
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 * -------------------------------------------------- */
static uint32_t xattr_datum_hashkey(int xprefix, const char *xname, const char *xvalue, int xsize)
{
	int name_len = strlen(xname);

	return crc32(xprefix, xname, name_len) ^ crc32(xprefix, xvalue, xsize);
}

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static int is_xattr_datum_unchecked(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
	struct jffs2_raw_node_ref *raw;
	int rc = 0;

	spin_lock(&c->erase_completion_lock);
	for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
		if (ref_flags(raw) == REF_UNCHECKED) {
			rc = 1;
			break;
		}
	}
	spin_unlock(&c->erase_completion_lock);
	return rc;
}

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static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
	/* must be called under down_write(xattr_sem) */
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	D1(dbg_xattr("%s: xid=%u, version=%u\n", __func__, xd->xid, xd->version));
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	if (xd->xname) {
		c->xdatum_mem_usage -= (xd->name_len + 1 + xd->value_len);
		kfree(xd->xname);
	}

	list_del_init(&xd->xindex);
	xd->hashkey = 0;
	xd->xname = NULL;
	xd->xvalue = NULL;
}

static void reclaim_xattr_datum(struct jffs2_sb_info *c)
{
	/* must be called under down_write(xattr_sem) */
	struct jffs2_xattr_datum *xd, *_xd;
	uint32_t target, before;
	static int index = 0;
	int count;

	if (c->xdatum_mem_threshold > c->xdatum_mem_usage)
		return;

	before = c->xdatum_mem_usage;
	target = c->xdatum_mem_usage * 4 / 5; /* 20% reduction */
	for (count = 0; count < XATTRINDEX_HASHSIZE; count++) {
		list_for_each_entry_safe(xd, _xd, &c->xattrindex[index], xindex) {
			if (xd->flags & JFFS2_XFLAGS_HOT) {
				xd->flags &= ~JFFS2_XFLAGS_HOT;
			} else if (!(xd->flags & JFFS2_XFLAGS_BIND)) {
				unload_xattr_datum(c, xd);
			}
			if (c->xdatum_mem_usage <= target)
				goto out;
		}
		index = (index+1) % XATTRINDEX_HASHSIZE;
	}
 out:
	JFFS2_NOTICE("xdatum_mem_usage from %u byte to %u byte (%u byte reclaimed)\n",
		     before, c->xdatum_mem_usage, before - c->xdatum_mem_usage);
}

static int do_verify_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
	/* must be called under down_write(xattr_sem) */
	struct jffs2_eraseblock *jeb;
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	struct jffs2_raw_node_ref *raw;
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	struct jffs2_raw_xattr rx;
	size_t readlen;
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	uint32_t crc, offset, totlen;
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	int rc;

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	spin_lock(&c->erase_completion_lock);
	offset = ref_offset(xd->node);
	if (ref_flags(xd->node) == REF_PRISTINE)
		goto complete;
	spin_unlock(&c->erase_completion_lock);
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	rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
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	if (rc || readlen != sizeof(rx)) {
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		JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
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			      rc, sizeof(rx), readlen, offset);
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		return rc ? rc : -EIO;
	}
	crc = crc32(0, &rx, sizeof(rx) - 4);
	if (crc != je32_to_cpu(rx.node_crc)) {
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		JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
			    offset, je32_to_cpu(rx.hdr_crc), crc);
		xd->flags |= JFFS2_XFLAGS_INVALID;
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		return JFFS2_XATTR_IS_CORRUPTED;
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	}
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	totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
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	if (je16_to_cpu(rx.magic) != JFFS2_MAGIC_BITMASK
	    || je16_to_cpu(rx.nodetype) != JFFS2_NODETYPE_XATTR
	    || je32_to_cpu(rx.totlen) != totlen
	    || je32_to_cpu(rx.xid) != xd->xid
	    || je32_to_cpu(rx.version) != xd->version) {
		JFFS2_ERROR("inconsistent xdatum at %#08x, magic=%#04x/%#04x, "
			    "nodetype=%#04x/%#04x, totlen=%u/%u, xid=%u/%u, version=%u/%u\n",
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			    offset, je16_to_cpu(rx.magic), JFFS2_MAGIC_BITMASK,
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			    je16_to_cpu(rx.nodetype), JFFS2_NODETYPE_XATTR,
			    je32_to_cpu(rx.totlen), totlen,
			    je32_to_cpu(rx.xid), xd->xid,
			    je32_to_cpu(rx.version), xd->version);
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		xd->flags |= JFFS2_XFLAGS_INVALID;
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		return JFFS2_XATTR_IS_CORRUPTED;
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	}
	xd->xprefix = rx.xprefix;
	xd->name_len = rx.name_len;
	xd->value_len = je16_to_cpu(rx.value_len);
	xd->data_crc = je32_to_cpu(rx.data_crc);

	spin_lock(&c->erase_completion_lock);
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 complete:
	for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
		jeb = &c->blocks[ref_offset(raw) / c->sector_size];
		totlen = PAD(ref_totlen(c, jeb, raw));
		if (ref_flags(raw) == REF_UNCHECKED) {
			c->unchecked_size -= totlen; c->used_size += totlen;
			jeb->unchecked_size -= totlen; jeb->used_size += totlen;
		}
		raw->flash_offset = ref_offset(raw) | ((xd->node==raw) ? REF_PRISTINE : REF_NORMAL);
	}
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	spin_unlock(&c->erase_completion_lock);

	/* unchecked xdatum is chained with c->xattr_unchecked */
	list_del_init(&xd->xindex);

	dbg_xattr("success on verfying xdatum (xid=%u, version=%u)\n",
		  xd->xid, xd->version);

	return 0;
}

static int do_load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
	/* must be called under down_write(xattr_sem) */
	char *data;
	size_t readlen;
	uint32_t crc, length;
	int i, ret, retry = 0;

	BUG_ON(ref_flags(xd->node) != REF_PRISTINE);
	BUG_ON(!list_empty(&xd->xindex));
 retry:
	length = xd->name_len + 1 + xd->value_len;
	data = kmalloc(length, GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	ret = jffs2_flash_read(c, ref_offset(xd->node)+sizeof(struct jffs2_raw_xattr),
			       length, &readlen, data);

	if (ret || length!=readlen) {
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		JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
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			      ret, length, readlen, ref_offset(xd->node));
		kfree(data);
		return ret ? ret : -EIO;
	}

	data[xd->name_len] = '\0';
	crc = crc32(0, data, length);
	if (crc != xd->data_crc) {
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		JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XATTR)"
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			      " at %#08x, read: 0x%08x calculated: 0x%08x\n",
			      ref_offset(xd->node), xd->data_crc, crc);
		kfree(data);
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		xd->flags |= JFFS2_XFLAGS_INVALID;
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		return JFFS2_XATTR_IS_CORRUPTED;
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	}

	xd->flags |= JFFS2_XFLAGS_HOT;
	xd->xname = data;
	xd->xvalue = data + xd->name_len+1;

	c->xdatum_mem_usage += length;

	xd->hashkey = xattr_datum_hashkey(xd->xprefix, xd->xname, xd->xvalue, xd->value_len);
	i = xd->hashkey % XATTRINDEX_HASHSIZE;
	list_add(&xd->xindex, &c->xattrindex[i]);
	if (!retry) {
		retry = 1;
		reclaim_xattr_datum(c);
		if (!xd->xname)
			goto retry;
	}

	dbg_xattr("success on loading xdatum (xid=%u, xprefix=%u, xname='%s')\n",
		  xd->xid, xd->xprefix, xd->xname);

	return 0;
}

static int load_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
	/* must be called under down_write(xattr_sem);
	 * rc < 0 : recoverable error, try again
	 * rc = 0 : success
	 * rc > 0 : Unrecoverable error, this node should be deleted.
	 */
	int rc = 0;
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	BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
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	if (xd->xname)
		return 0;
	if (xd->flags & JFFS2_XFLAGS_INVALID)
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		return JFFS2_XATTR_IS_CORRUPTED;
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	if (unlikely(is_xattr_datum_unchecked(c, xd)))
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		rc = do_verify_xattr_datum(c, xd);
	if (!rc)
		rc = do_load_xattr_datum(c, xd);
	return rc;
}

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static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
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{
	/* must be called under down_write(xattr_sem) */
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	struct jffs2_raw_xattr rx;
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	struct kvec vecs[2];
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	size_t length;
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	int rc, totlen;
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	uint32_t phys_ofs = write_ofs(c);
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	BUG_ON(!xd->xname);
	BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
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	vecs[0].iov_base = &rx;
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	vecs[0].iov_len = sizeof(rx);
	vecs[1].iov_base = xd->xname;
	vecs[1].iov_len = xd->name_len + 1 + xd->value_len;
	totlen = vecs[0].iov_len + vecs[1].iov_len;

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	/* Setup raw-xattr */
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	memset(&rx, 0, sizeof(rx));
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	rx.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	rx.nodetype = cpu_to_je16(JFFS2_NODETYPE_XATTR);
	rx.totlen = cpu_to_je32(PAD(totlen));
	rx.hdr_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_unknown_node) - 4));

	rx.xid = cpu_to_je32(xd->xid);
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	rx.version = cpu_to_je32(++xd->version);
	rx.xprefix = xd->xprefix;
	rx.name_len = xd->name_len;
	rx.value_len = cpu_to_je16(xd->value_len);
	rx.data_crc = cpu_to_je32(crc32(0, vecs[1].iov_base, vecs[1].iov_len));
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	rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));

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	rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
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	if (rc || totlen != length) {
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		JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
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			      rc, totlen, length, phys_ofs);
		rc = rc ? rc : -EIO;
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		if (length)
			jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);

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		return rc;
	}
	/* success */
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	jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
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	dbg_xattr("success on saving xdatum (xid=%u, version=%u, xprefix=%u, xname='%s')\n",
		  xd->xid, xd->version, xd->xprefix, xd->xname);

	return 0;
}

static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
						    int xprefix, const char *xname,
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						    const char *xvalue, int xsize)
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{
	/* must be called under down_write(xattr_sem) */
	struct jffs2_xattr_datum *xd;
	uint32_t hashkey, name_len;
	char *data;
	int i, rc;

	/* Search xattr_datum has same xname/xvalue by index */
	hashkey = xattr_datum_hashkey(xprefix, xname, xvalue, xsize);
	i = hashkey % XATTRINDEX_HASHSIZE;
	list_for_each_entry(xd, &c->xattrindex[i], xindex) {
		if (xd->hashkey==hashkey
		    && xd->xprefix==xprefix
		    && xd->value_len==xsize
		    && !strcmp(xd->xname, xname)
		    && !memcmp(xd->xvalue, xvalue, xsize)) {
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			atomic_inc(&xd->refcnt);
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			return xd;
		}
	}

	/* Not found, Create NEW XATTR-Cache */
	name_len = strlen(xname);

	xd = jffs2_alloc_xattr_datum();
	if (!xd)
		return ERR_PTR(-ENOMEM);

	data = kmalloc(name_len + 1 + xsize, GFP_KERNEL);
	if (!data) {
		jffs2_free_xattr_datum(xd);
		return ERR_PTR(-ENOMEM);
	}
	strcpy(data, xname);
	memcpy(data + name_len + 1, xvalue, xsize);

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	atomic_set(&xd->refcnt, 1);
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	xd->xid = ++c->highest_xid;
	xd->flags |= JFFS2_XFLAGS_HOT;
	xd->xprefix = xprefix;

	xd->hashkey = hashkey;
	xd->xname = data;
	xd->xvalue = data + name_len + 1;
	xd->name_len = name_len;
	xd->value_len = xsize;
	xd->data_crc = crc32(0, data, xd->name_len + 1 + xd->value_len);

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	rc = save_xattr_datum(c, xd);
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	if (rc) {
		kfree(xd->xname);
		jffs2_free_xattr_datum(xd);
		return ERR_PTR(rc);
	}

	/* Insert Hash Index */
	i = hashkey % XATTRINDEX_HASHSIZE;
	list_add(&xd->xindex, &c->xattrindex[i]);

	c->xdatum_mem_usage += (xd->name_len + 1 + xd->value_len);
	reclaim_xattr_datum(c);

	return xd;
}

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static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
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{
	/* must be called under down_write(xattr_sem) */
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	if (atomic_dec_and_lock(&xd->refcnt, &c->erase_completion_lock)) {
		unload_xattr_datum(c, xd);
		xd->flags |= JFFS2_XFLAGS_DEAD;
		if (xd->node == (void *)xd) {
			BUG_ON(!(xd->flags & JFFS2_XFLAGS_INVALID));
			jffs2_free_xattr_datum(xd);
		} else {
			list_add(&xd->xindex, &c->xattr_dead_list);
		}
		spin_unlock(&c->erase_completion_lock);

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		dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
			  xd->xid, xd->version);
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	}
}

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/* -------- xref related functions ------------------
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 * verify_xattr_ref(c, ref)
 *   is used to load xref information from medium. Because summary data does not
 *   contain xid/ino, it's necessary to verify once while mounting process.
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 * save_xattr_ref(c, ref)
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 *   is used to write xref to medium. If delete marker is marked, it write
 *   a delete marker of xref into medium.
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 * create_xattr_ref(c, ic, xd)
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 *   is used to create a new xref and write to medium.
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 * delete_xattr_ref(c, ref)
 *   is used to delete jffs2_xattr_ref. It marks xref XREF_DELETE_MARKER,
 *   and allows GC to reclaim those physical nodes.
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 * jffs2_xattr_delete_inode(c, ic)
 *   is called to remove xrefs related to obsolete inode when inode is unlinked.
 * jffs2_xattr_free_inode(c, ic)
 *   is called to release xattr related objects when unmounting. 
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 * check_xattr_ref_inode(c, ic)
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 *   is used to confirm inode does not have duplicate xattr name/value pair.
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 * jffs2_xattr_do_crccheck_inode(c, ic)
 *   is used to force xattr data integrity check during the initial gc scan.
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 * -------------------------------------------------- */
static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
{
	struct jffs2_eraseblock *jeb;
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	struct jffs2_raw_node_ref *raw;
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	struct jffs2_raw_xref rr;
	size_t readlen;
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	uint32_t crc, offset, totlen;
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	int rc;

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	spin_lock(&c->erase_completion_lock);
	if (ref_flags(ref->node) != REF_UNCHECKED)
		goto complete;
	offset = ref_offset(ref->node);
	spin_unlock(&c->erase_completion_lock);
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	rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
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	if (rc || sizeof(rr) != readlen) {
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		JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
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			      rc, sizeof(rr), readlen, offset);
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		return rc ? rc : -EIO;
	}
	/* obsolete node */
	crc = crc32(0, &rr, sizeof(rr) - 4);
	if (crc != je32_to_cpu(rr.node_crc)) {
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		JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
			    offset, je32_to_cpu(rr.node_crc), crc);
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		return JFFS2_XATTR_IS_CORRUPTED;
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	}
	if (je16_to_cpu(rr.magic) != JFFS2_MAGIC_BITMASK
	    || je16_to_cpu(rr.nodetype) != JFFS2_NODETYPE_XREF
	    || je32_to_cpu(rr.totlen) != PAD(sizeof(rr))) {
		JFFS2_ERROR("inconsistent xref at %#08x, magic=%#04x/%#04x, "
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			    "nodetype=%#04x/%#04x, totlen=%u/%zu\n",
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			    offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
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			    je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
			    je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
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		return JFFS2_XATTR_IS_CORRUPTED;
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	}
	ref->ino = je32_to_cpu(rr.ino);
	ref->xid = je32_to_cpu(rr.xid);
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	ref->xseqno = je32_to_cpu(rr.xseqno);
	if (ref->xseqno > c->highest_xseqno)
		c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
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	spin_lock(&c->erase_completion_lock);
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 complete:
	for (raw=ref->node; raw != (void *)ref; raw=raw->next_in_ino) {
		jeb = &c->blocks[ref_offset(raw) / c->sector_size];
		totlen = PAD(ref_totlen(c, jeb, raw));
		if (ref_flags(raw) == REF_UNCHECKED) {
			c->unchecked_size -= totlen; c->used_size += totlen;
			jeb->unchecked_size -= totlen; jeb->used_size += totlen;
		}
		raw->flash_offset = ref_offset(raw) | ((ref->node==raw) ? REF_PRISTINE : REF_NORMAL);
	}
498 499 500 501 502 503 504
	spin_unlock(&c->erase_completion_lock);

	dbg_xattr("success on verifying xref (ino=%u, xid=%u) at %#08x\n",
		  ref->ino, ref->xid, ref_offset(ref->node));
	return 0;
}

505
static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
506 507 508
{
	/* must be called under down_write(xattr_sem) */
	struct jffs2_raw_xref rr;
509
	size_t length;
510
	uint32_t xseqno, phys_ofs = write_ofs(c);
511 512 513 514 515 516 517
	int ret;

	rr.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	rr.nodetype = cpu_to_je16(JFFS2_NODETYPE_XREF);
	rr.totlen = cpu_to_je32(PAD(sizeof(rr)));
	rr.hdr_crc = cpu_to_je32(crc32(0, &rr, sizeof(struct jffs2_unknown_node) - 4));

518 519 520 521 522 523 524 525 526 527
	xseqno = (c->highest_xseqno += 2);
	if (is_xattr_ref_dead(ref)) {
		xseqno |= XREF_DELETE_MARKER;
		rr.ino = cpu_to_je32(ref->ino);
		rr.xid = cpu_to_je32(ref->xid);
	} else {
		rr.ino = cpu_to_je32(ref->ic->ino);
		rr.xid = cpu_to_je32(ref->xd->xid);
	}
	rr.xseqno = cpu_to_je32(xseqno);
528 529 530 531
	rr.node_crc = cpu_to_je32(crc32(0, &rr, sizeof(rr) - 4));

	ret = jffs2_flash_write(c, phys_ofs, sizeof(rr), &length, (char *)&rr);
	if (ret || sizeof(rr) != length) {
532
		JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
533 534
			      ret, sizeof(rr), length, phys_ofs);
		ret = ret ? ret : -EIO;
535 536 537
		if (length)
			jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);

538 539
		return ret;
	}
540 541 542
	/* success */
	ref->xseqno = xseqno;
	jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
543 544 545 546 547 548 549

	dbg_xattr("success on saving xref (ino=%u, xid=%u)\n", ref->ic->ino, ref->xd->xid);

	return 0;
}

static struct jffs2_xattr_ref *create_xattr_ref(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic,
550
						struct jffs2_xattr_datum *xd)
551 552 553 554 555 556 557 558 559 560 561
{
	/* must be called under down_write(xattr_sem) */
	struct jffs2_xattr_ref *ref;
	int ret;

	ref = jffs2_alloc_xattr_ref();
	if (!ref)
		return ERR_PTR(-ENOMEM);
	ref->ic = ic;
	ref->xd = xd;

562
	ret = save_xattr_ref(c, ref);
563 564 565 566 567 568
	if (ret) {
		jffs2_free_xattr_ref(ref);
		return ERR_PTR(ret);
	}

	/* Chain to inode */
569 570
	ref->next = ic->xref;
	ic->xref = ref;
571 572 573 574

	return ref; /* success */
}

575
static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
576 577 578 579 580
{
	/* must be called under down_write(xattr_sem) */
	struct jffs2_xattr_datum *xd;

	xd = ref->xd;
581
	ref->xseqno |= XREF_DELETE_MARKER;
582 583 584 585 586 587 588
	ref->ino = ref->ic->ino;
	ref->xid = ref->xd->xid;
	spin_lock(&c->erase_completion_lock);
	ref->next = c->xref_dead_list;
	c->xref_dead_list = ref;
	spin_unlock(&c->erase_completion_lock);

589 590
	dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
		  ref->ino, ref->xid, ref->xseqno);
591

592
	unrefer_xattr_datum(c, xd);
593 594
}

595 596
void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
{
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)
602 603 604
		return;

	down_write(&c->xattr_sem);
605 606 607
	for (ref = ic->xref; ref; ref = _ref) {
		_ref = ref->next;
		delete_xattr_ref(c, ref);
608
	}
609
	ic->xref = NULL;
610 611 612 613 614 615 616 617 618 619
	up_write(&c->xattr_sem);
}

void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
{
	/* It's called from jffs2_free_ino_caches() until unmounting FS. */
	struct jffs2_xattr_datum *xd;
	struct jffs2_xattr_ref *ref, *_ref;

	down_write(&c->xattr_sem);
620 621
	for (ref = ic->xref; ref; ref = _ref) {
		_ref = ref->next;
622
		xd = ref->xd;
623
		if (atomic_dec_and_test(&xd->refcnt)) {
624 625 626 627 628
			unload_xattr_datum(c, xd);
			jffs2_free_xattr_datum(xd);
		}
		jffs2_free_xattr_ref(ref);
	}
629
	ic->xref = NULL;
630 631 632
	up_write(&c->xattr_sem);
}

633
static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
634
{
635
	/* success of check_xattr_ref_inode() means that inode (ic) dose not have
636 637 638
	 * duplicate name/value pairs. If duplicate name/value pair would be found,
	 * one will be removed.
	 */
639
	struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
640 641 642 643 644 645 646
	int rc = 0;

	if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
		return 0;
	down_write(&c->xattr_sem);
 retry:
	rc = 0;
647
	for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
648 649 650
		if (!ref->xd->xname) {
			rc = load_xattr_datum(c, ref->xd);
			if (unlikely(rc > 0)) {
651
				*pref = ref->next;
652
				delete_xattr_ref(c, ref);
653 654 655 656
				goto retry;
			} else if (unlikely(rc < 0))
				goto out;
		}
657
		for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
658 659 660 661 662
			if (!cmp->xd->xname) {
				ref->xd->flags |= JFFS2_XFLAGS_BIND;
				rc = load_xattr_datum(c, cmp->xd);
				ref->xd->flags &= ~JFFS2_XFLAGS_BIND;
				if (unlikely(rc > 0)) {
663
					*pcmp = cmp->next;
664
					delete_xattr_ref(c, cmp);
665 666 667 668 669 670
					goto retry;
				} else if (unlikely(rc < 0))
					goto out;
			}
			if (ref->xd->xprefix == cmp->xd->xprefix
			    && !strcmp(ref->xd->xname, cmp->xd->xname)) {
671 672
				if (ref->xseqno > cmp->xseqno) {
					*pcmp = cmp->next;
673
					delete_xattr_ref(c, cmp);
674 675
				} else {
					*pref = ref->next;
676
					delete_xattr_ref(c, ref);
677
				}
678 679 680 681 682 683 684 685 686 687 688
				goto retry;
			}
		}
	}
	ic->flags |= INO_FLAGS_XATTR_CHECKED;
 out:
	up_write(&c->xattr_sem);

	return rc;
}

689 690 691 692 693
void jffs2_xattr_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
{
	check_xattr_ref_inode(c, ic);
}

694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712
/* -------- xattr subsystem functions ---------------
 * jffs2_init_xattr_subsystem(c)
 *   is used to initialize semaphore and list_head, and some variables.
 * jffs2_find_xattr_datum(c, xid)
 *   is used to lookup xdatum while scanning process.
 * jffs2_clear_xattr_subsystem(c)
 *   is used to release any xattr related objects.
 * jffs2_build_xattr_subsystem(c)
 *   is used to associate xdatum and xref while super block building process.
 * jffs2_setup_xattr_datum(c, xid, version)
 *   is used to insert xdatum while scanning process.
 * -------------------------------------------------- */
void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c)
{
	int i;

	for (i=0; i < XATTRINDEX_HASHSIZE; i++)
		INIT_LIST_HEAD(&c->xattrindex[i]);
	INIT_LIST_HEAD(&c->xattr_unchecked);
713 714
	INIT_LIST_HEAD(&c->xattr_dead_list);
	c->xref_dead_list = NULL;
715
	c->xref_temp = NULL;
716 717

	init_rwsem(&c->xattr_sem);
718 719
	c->highest_xid = 0;
	c->highest_xseqno = 0;
720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744
	c->xdatum_mem_usage = 0;
	c->xdatum_mem_threshold = 32 * 1024;	/* Default 32KB */
}

static struct jffs2_xattr_datum *jffs2_find_xattr_datum(struct jffs2_sb_info *c, uint32_t xid)
{
	struct jffs2_xattr_datum *xd;
	int i = xid % XATTRINDEX_HASHSIZE;

	/* It's only used in scanning/building process. */
	BUG_ON(!(c->flags & (JFFS2_SB_FLAG_SCANNING|JFFS2_SB_FLAG_BUILDING)));

	list_for_each_entry(xd, &c->xattrindex[i], xindex) {
		if (xd->xid==xid)
			return xd;
	}
	return NULL;
}

void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c)
{
	struct jffs2_xattr_datum *xd, *_xd;
	struct jffs2_xattr_ref *ref, *_ref;
	int i;

745 746
	for (ref=c->xref_temp; ref; ref = _ref) {
		_ref = ref->next;
747
		jffs2_free_xattr_ref(ref);
748
	}
749 750 751 752 753

	for (ref=c->xref_dead_list; ref; ref = _ref) {
		_ref = ref->next;
		jffs2_free_xattr_ref(ref);
	}
754 755 756 757 758 759 760 761 762

	for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
		list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
			list_del(&xd->xindex);
			if (xd->xname)
				kfree(xd->xname);
			jffs2_free_xattr_datum(xd);
		}
	}
763 764 765 766 767

	list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
		list_del(&xd->xindex);
		jffs2_free_xattr_datum(xd);
	}
768 769 770 771
	list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
		list_del(&xd->xindex);
		jffs2_free_xattr_datum(xd);
	}
772 773
}

774
#define XREF_TMPHASH_SIZE	(128)
775 776 777
void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
{
	struct jffs2_xattr_ref *ref, *_ref;
778
	struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
779 780
	struct jffs2_xattr_datum *xd, *_xd;
	struct jffs2_inode_cache *ic;
781 782
	struct jffs2_raw_node_ref *raw;
	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;
784 785 786

	BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));

787
	/* Phase.1 : Merge same xref */
788 789
	for (i=0; i < XREF_TMPHASH_SIZE; i++)
		xref_tmphash[i] = NULL;
790
	for (ref=c->xref_temp; ref; ref=_ref) {
791 792
		struct jffs2_xattr_ref *tmp;

793
		_ref = ref->next;
794 795
		if (ref_flags(ref->node) != REF_PRISTINE) {
			if (verify_xattr_ref(c, ref)) {
796 797 798
				BUG_ON(ref->node->next_in_ino != (void *)ref);
				ref->node->next_in_ino = NULL;
				jffs2_mark_node_obsolete(c, ref->node);
799 800 801 802
				jffs2_free_xattr_ref(ref);
				continue;
			}
		}
803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818

		i = (ref->ino ^ ref->xid) % XREF_TMPHASH_SIZE;
		for (tmp=xref_tmphash[i]; tmp; tmp=tmp->next) {
			if (tmp->ino == ref->ino && tmp->xid == ref->xid)
				break;
		}
		if (tmp) {
			raw = ref->node;
			if (ref->xseqno > tmp->xseqno) {
				tmp->xseqno = ref->xseqno;
				raw->next_in_ino = tmp->node;
				tmp->node = raw;
			} else {
				raw->next_in_ino = tmp->node->next_in_ino;
				tmp->node->next_in_ino = raw;
			}
819 820
			jffs2_free_xattr_ref(ref);
			continue;
821 822 823
		} else {
			ref->next = xref_tmphash[i];
			xref_tmphash[i] = ref;
824 825
		}
	}
826
	c->xref_temp = NULL;
827

828
	/* Phase.2 : Bind xref with inode_cache and xattr_datum */
829 830
	for (i=0; i < XREF_TMPHASH_SIZE; i++) {
		for (ref=xref_tmphash[i]; ref; ref=_ref) {
831
			xref_count++;
832 833 834 835
			_ref = ref->next;
			if (is_xattr_ref_dead(ref)) {
				ref->next = c->xref_dead_list;
				c->xref_dead_list = ref;
836
				xref_dead_count++;
837 838 839 840 841 842
				continue;
			}
			/* At this point, ref->xid and ref->ino contain XID and inode number.
			   ref->xd and ref->ic are not valid yet. */
			xd = jffs2_find_xattr_datum(c, ref->xid);
			ic = jffs2_get_ino_cache(c, ref->ino);
843
			if (!xd || !ic || !ic->pino_nlink) {
844 845 846
				dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
					  ref->ino, ref->xid, ref->xseqno);
				ref->xseqno |= XREF_DELETE_MARKER;
847 848
				ref->next = c->xref_dead_list;
				c->xref_dead_list = ref;
849
				xref_orphan_count++;
850 851 852 853
				continue;
			}
			ref->xd = xd;
			ref->ic = ic;
854
			atomic_inc(&xd->refcnt);
855 856 857 858 859
			ref->next = ic->xref;
			ic->xref = ref;
		}
	}

860
	/* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
861 862
	for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
		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)) {
866 867 868
				dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
					  xd->xid, xd->version);
				xd->flags |= JFFS2_XFLAGS_DEAD;
869
				list_add(&xd->xindex, &c->xattr_unchecked);
870
				xdatum_orphan_count++;
871 872
				continue;
			}
873 874 875
			if (is_xattr_datum_unchecked(c, xd)) {
				dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
					  xd->xid, xd->version);
876 877 878 879 880 881
				list_add(&xd->xindex, &c->xattr_unchecked);
				xdatum_unchecked_count++;
			}
		}
	}
	/* build complete */
882 883 884 885 886
	JFFS2_NOTICE("complete building xattr subsystem, %u of xdatum"
		     " (%u unchecked, %u orphan) and "
		     "%u of xref (%u dead, %u orphan) found.\n",
		     xdatum_count, xdatum_unchecked_count, xdatum_orphan_count,
		     xref_count, xref_dead_count, xref_orphan_count);
887 888 889 890 891
}

struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
						  uint32_t xid, uint32_t version)
{
892
	struct jffs2_xattr_datum *xd;
893

894 895 896 897 898 899 900 901 902 903
	xd = jffs2_find_xattr_datum(c, xid);
	if (!xd) {
		xd = jffs2_alloc_xattr_datum();
		if (!xd)
			return ERR_PTR(-ENOMEM);
		xd->xid = xid;
		xd->version = version;
		if (xd->xid > c->highest_xid)
			c->highest_xid = xd->xid;
		list_add_tail(&xd->xindex, &c->xattrindex[xid % XATTRINDEX_HASHSIZE]);
904 905 906 907 908 909 910 911 912 913 914 915 916 917
	}
	return xd;
}

/* -------- xattr subsystem functions ---------------
 * xprefix_to_handler(xprefix)
 *   is used to translate xprefix into xattr_handler.
 * jffs2_listxattr(dentry, buffer, size)
 *   is an implementation of listxattr handler on jffs2.
 * do_jffs2_getxattr(inode, xprefix, xname, buffer, size)
 *   is an implementation of getxattr handler on jffs2.
 * do_jffs2_setxattr(inode, xprefix, xname, buffer, size, flags)
 *   is an implementation of setxattr handler on jffs2.
 * -------------------------------------------------- */
918
const struct xattr_handler *jffs2_xattr_handlers[] = {
919 920 921 922 923 924 925 926 927 928 929 930
	&jffs2_user_xattr_handler,
#ifdef CONFIG_JFFS2_FS_SECURITY
	&jffs2_security_xattr_handler,
#endif
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
	&jffs2_acl_access_xattr_handler,
	&jffs2_acl_default_xattr_handler,
#endif
	&jffs2_trusted_xattr_handler,
	NULL
};

931 932
static const struct xattr_handler *xprefix_to_handler(int xprefix) {
	const struct xattr_handler *ret;
933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966

	switch (xprefix) {
	case JFFS2_XPREFIX_USER:
		ret = &jffs2_user_xattr_handler;
		break;
#ifdef CONFIG_JFFS2_FS_SECURITY
	case JFFS2_XPREFIX_SECURITY:
		ret = &jffs2_security_xattr_handler;
		break;
#endif
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
	case JFFS2_XPREFIX_ACL_ACCESS:
		ret = &jffs2_acl_access_xattr_handler;
		break;
	case JFFS2_XPREFIX_ACL_DEFAULT:
		ret = &jffs2_acl_default_xattr_handler;
		break;
#endif
	case JFFS2_XPREFIX_TRUSTED:
		ret = &jffs2_trusted_xattr_handler;
		break;
	default:
		ret = NULL;
		break;
	}
	return ret;
}

ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
	struct inode *inode = dentry->d_inode;
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	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;
970 971 972
	ssize_t len, rc;
	int retry = 0;

973
	rc = check_xattr_ref_inode(c, ic);
974 975 976 977 978 979
	if (unlikely(rc))
		return rc;

	down_read(&c->xattr_sem);
 retry:
	len = 0;
980
	for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
981 982 983 984 985 986 987 988 989 990 991 992
		BUG_ON(ref->ic != ic);
		xd = ref->xd;
		if (!xd->xname) {
			/* xdatum is unchached */
			if (!retry) {
				retry = 1;
				up_read(&c->xattr_sem);
				down_write(&c->xattr_sem);
				goto retry;
			} else {
				rc = load_xattr_datum(c, xd);
				if (unlikely(rc > 0)) {
993
					*pref = ref->next;
994
					delete_xattr_ref(c, ref);
995 996 997 998 999 1000 1001 1002 1003
					goto retry;
				} else if (unlikely(rc < 0))
					goto out;
			}
		}
		xhandle = xprefix_to_handler(xd->xprefix);
		if (!xhandle)
			continue;
		if (buffer) {
1004 1005
			rc = xhandle->list(dentry, buffer+len, size-len,
					   xd->xname, xd->name_len, xd->flags);
1006
		} else {
1007 1008
			rc = xhandle->list(dentry, NULL, 0, xd->xname,
					   xd->name_len, xd->flags);
1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030
		}
		if (rc < 0)
			goto out;
		len += rc;
	}
	rc = len;
 out:
	if (!retry) {
		up_read(&c->xattr_sem);
	} else {
		up_write(&c->xattr_sem);
	}
	return rc;
}

int do_jffs2_getxattr(struct inode *inode, int xprefix, const char *xname,
		      char *buffer, size_t size)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	struct jffs2_inode_cache *ic = f->inocache;
	struct jffs2_xattr_datum *xd;
1031
	struct jffs2_xattr_ref *ref, **pref;
1032 1033
	int rc, retry = 0;

1034
	rc = check_xattr_ref_inode(c, ic);
1035 1036 1037 1038 1039
	if (unlikely(rc))
		return rc;

	down_read(&c->xattr_sem);
 retry:
1040
	for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055
		BUG_ON(ref->ic!=ic);

		xd = ref->xd;
		if (xd->xprefix != xprefix)
			continue;
		if (!xd->xname) {
			/* xdatum is unchached */
			if (!retry) {
				retry = 1;
				up_read(&c->xattr_sem);
				down_write(&c->xattr_sem);
				goto retry;
			} else {
				rc = load_xattr_datum(c, xd);
				if (unlikely(rc > 0)) {
1056
					*pref = ref->next;
1057
					delete_xattr_ref(c, ref);
1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092
					goto retry;
				} else if (unlikely(rc < 0)) {
					goto out;
				}
			}
		}
		if (!strcmp(xname, xd->xname)) {
			rc = xd->value_len;
			if (buffer) {
				if (size < rc) {
					rc = -ERANGE;
				} else {
					memcpy(buffer, xd->xvalue, rc);
				}
			}
			goto out;
		}
	}
	rc = -ENODATA;
 out:
	if (!retry) {
		up_read(&c->xattr_sem);
	} else {
		up_write(&c->xattr_sem);
	}
	return rc;
}

int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
		      const char *buffer, size_t size, int flags)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	struct jffs2_inode_cache *ic = f->inocache;
	struct jffs2_xattr_datum *xd;
1093
	struct jffs2_xattr_ref *ref, *newref, **pref;
1094
	uint32_t length, request;
1095 1096
	int rc;

1097
	rc = check_xattr_ref_inode(c, ic);
1098 1099 1100 1101
	if (unlikely(rc))
		return rc;

	request = PAD(sizeof(struct jffs2_raw_xattr) + strlen(xname) + 1 + size);
1102
	rc = jffs2_reserve_space(c, request, &length,
1103 1104 1105 1106 1107 1108 1109 1110 1111
				 ALLOC_NORMAL, JFFS2_SUMMARY_XATTR_SIZE);
	if (rc) {
		JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
		return rc;
	}

	/* Find existing xattr */
	down_write(&c->xattr_sem);
 retry:
1112
	for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
1113 1114 1115 1116 1117 1118
		xd = ref->xd;
		if (xd->xprefix != xprefix)
			continue;
		if (!xd->xname) {
			rc = load_xattr_datum(c, xd);
			if (unlikely(rc > 0)) {
1119
				*pref = ref->next;
1120
				delete_xattr_ref(c, ref);
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
				goto retry;
			} else if (unlikely(rc < 0))
				goto out;
		}
		if (!strcmp(xd->xname, xname)) {
			if (flags & XATTR_CREATE) {
				rc = -EEXIST;
				goto out;
			}
			if (!buffer) {
1131 1132 1133 1134 1135 1136 1137 1138 1139 1140
				ref->ino = ic->ino;
				ref->xid = xd->xid;
				ref->xseqno |= XREF_DELETE_MARKER;
				rc = save_xattr_ref(c, ref);
				if (!rc) {
					*pref = ref->next;
					spin_lock(&c->erase_completion_lock);
					ref->next = c->xref_dead_list;
					c->xref_dead_list = ref;
					spin_unlock(&c->erase_completion_lock);
1141
					unrefer_xattr_datum(c, xd);
1142 1143 1144 1145 1146
				} else {
					ref->ic = ic;
					ref->xd = xd;
					ref->xseqno &= ~XREF_DELETE_MARKER;
				}
1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157
				goto out;
			}
			goto found;
		}
	}
	/* not found */
	if (flags & XATTR_REPLACE) {
		rc = -ENODATA;
		goto out;
	}
	if (!buffer) {
1158
		rc = -ENODATA;
1159 1160 1161
		goto out;
	}
 found:
1162
	xd = create_xattr_datum(c, xprefix, xname, buffer, size);
1163 1164 1165 1166 1167 1168 1169 1170 1171
	if (IS_ERR(xd)) {
		rc = PTR_ERR(xd);
		goto out;
	}
	up_write(&c->xattr_sem);
	jffs2_complete_reservation(c);

	/* create xattr_ref */
	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 1176
	if (rc) {
		JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
1177
		unrefer_xattr_datum(c, xd);
1178 1179 1180
		up_write(&c->xattr_sem);
		return rc;
	}
1181 1182
	if (ref)
		*pref = ref->next;
1183
	newref = create_xattr_ref(c, ic, xd);
1184
	if (IS_ERR(newref)) {
1185 1186 1187 1188
		if (ref) {
			ref->next = ic->xref;
			ic->xref = ref;
		}
1189
		rc = PTR_ERR(newref);
1190
		unrefer_xattr_datum(c, xd);
1191
	} else if (ref) {
1192
		delete_xattr_ref(c, ref);
1193 1194 1195 1196 1197 1198 1199 1200
	}
 out:
	up_write(&c->xattr_sem);
	jffs2_complete_reservation(c);
	return rc;
}

/* -------- 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 1205 1206
 *   is used to move xref into new node.
 * jffs2_verify_xattr(c)
 *   is used to call do_verify_xattr_datum() before garbage collecting.
1207 1208 1209 1210
 * jffs2_release_xattr_datum(c, xd)
 *   is used to release an in-memory object of xdatum.
 * jffs2_release_xattr_ref(c, ref)
 *   is used to release an in-memory object of xref.
1211
 * -------------------------------------------------- */
1212 1213
int jffs2_garbage_collect_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd,
				      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 1220
	if (xd->node != raw)
		goto out;
1221
	if (xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID))
1222
		goto out;
1223

1224 1225 1226 1227
	rc = load_xattr_datum(c, xd);
	if (unlikely(rc)) {
		rc = (rc > 0) ? 0 : rc;
		goto out;
1228
	}
1229 1230 1231
	old_ofs = ref_offset(xd->node);
	totlen = PAD(sizeof(struct jffs2_raw_xattr)
			+ xd->name_len + 1 + xd->value_len);
1232
	rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XATTR_SIZE);
1233 1234
	if (rc) {
		JFFS2_WARNING("jffs2_reserve_space_gc()=%d, request=%u\n", rc, totlen);
1235
		goto out;
1236
	}
1237
	rc = save_xattr_datum(c, xd);
1238 1239 1240
	if (!rc)
		dbg_xattr("xdatum (xid=%u, version=%u) GC'ed from %#08x to %08x\n",
			  xd->xid, xd->version, old_ofs, ref_offset(xd->node));
1241
 out:
1242 1243
	if (!rc)
		jffs2_mark_node_obsolete(c, raw);
1244
	up_write(&c->xattr_sem);
1245 1246 1247
	return rc;
}

1248 1249
int jffs2_garbage_collect_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref,
				    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 1256
	BUG_ON(!ref->node);

1257 1258 1259 1260 1261
	if (ref->node != raw)
		goto out;
	if (is_xattr_ref_dead(ref) && (raw->next_in_ino == (void *)ref))
		goto out;

1262 1263
	old_ofs = ref_offset(ref->node);
	totlen = ref_totlen(c, c->gcblock, ref->node);
1264

1265
	rc = jffs2_reserve_space_gc(c, totlen, &length, JFFS2_SUMMARY_XREF_SIZE);
1266 1267
	if (rc) {
		JFFS2_WARNING("%s: jffs2_reserve_space_gc() = %d, request = %u\n",
1268
			      __func__, rc, totlen);
1269 1270
		rc = rc ? rc : -EBADFD;
		goto out;
1271
	}
1272
	rc = save_xattr_ref(c, ref);
1273 1274 1275
	if (!rc)
		dbg_xattr("xref (ino=%u, xid=%u) GC'ed from %#08x to %08x\n",
			  ref->ic->ino, ref->xd->xid, old_ofs, ref_offset(ref->node));
1276
 out:
1277 1278
	if (!rc)
		jffs2_mark_node_obsolete(c, raw);
1279
	up_write(&c->xattr_sem);
1280 1281 1282 1283 1284 1285
	return rc;
}

int jffs2_verify_xattr(struct jffs2_sb_info *c)
{
	struct jffs2_xattr_datum *xd, *_xd;
1286 1287 1288
	struct jffs2_eraseblock *jeb;
	struct jffs2_raw_node_ref *raw;
	uint32_t totlen;
1289 1290 1291 1292 1293
	int rc;

	down_write(&c->xattr_sem);
	list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
		rc = do_verify_xattr_datum(c, xd);
1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306
		if (rc < 0)
			continue;
		list_del_init(&xd->xindex);
		spin_lock(&c->erase_completion_lock);
		for (raw=xd->node; raw != (void *)xd; raw=raw->next_in_ino) {
			if (ref_flags(raw) != REF_UNCHECKED)
				continue;
			jeb = &c->blocks[ref_offset(raw) / c->sector_size];
			totlen = PAD(ref_totlen(c, jeb, raw));
			c->unchecked_size -= totlen; c->used_size += totlen;
			jeb->unchecked_size -= totlen; jeb->used_size += totlen;
			raw->flash_offset = ref_offset(raw)
				| ((xd->node == (void *)raw) ? REF_PRISTINE : REF_NORMAL);
1307
		}
1308
		if (xd->flags & JFFS2_XFLAGS_DEAD)
1309 1310
			list_add(&xd->xindex, &c->xattr_dead_list);
		spin_unlock(&c->erase_completion_lock);
1311 1312 1313 1314
	}
	up_write(&c->xattr_sem);
	return list_empty(&c->xattr_unchecked) ? 1 : 0;
}
1315 1316 1317 1318

void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
	/* must be called under spin_lock(&c->erase_completion_lock) */
1319
	if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339
		return;

	list_del(&xd->xindex);
	jffs2_free_xattr_datum(xd);
}

void jffs2_release_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
{
	/* must be called under spin_lock(&c->erase_completion_lock) */
	struct jffs2_xattr_ref *tmp, **ptmp;

	if (ref->node != (void *)ref)
		return;

	for (tmp=c->xref_dead_list, ptmp=&c->xref_dead_list; tmp; ptmp=&tmp->next, tmp=tmp->next) {
		if (ref == tmp) {
			*ptmp = tmp->next;
			break;
		}
	}
1340
	jffs2_free_xattr_ref(ref);
1341
}