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xattr.c
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/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright © 2006 NEC Corporation
*
* Created by KaiGai Kohei <[email protected]>
*
* For licensing information, see the file 'LICENCE' in this directory.
*
*/
#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).
* 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.
* 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
* memory usage by cache is over c->xdatum_mem_threshold. Currently, this threshold
* 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().
* save_xattr_datum(c, xd)
* is used to write xdatum to medium. xd->version will be incremented.
* create_xattr_datum(c, xprefix, xname, xvalue, xsize)
* is used to create new xdatum and write to medium.
* 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.
* -------------------------------------------------- */
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);
}
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;
}
static void unload_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
/* must be called under down_write(xattr_sem) */
D1(dbg_xattr("%s: xid=%u, version=%u\n", __func__, xd->xid, xd->version));
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;
struct jffs2_raw_node_ref *raw;
struct jffs2_raw_xattr rx;
size_t readlen;
uint32_t crc, offset, totlen;
int rc;
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);
rc = jffs2_flash_read(c, offset, sizeof(rx), &readlen, (char *)&rx);
if (rc || readlen != sizeof(rx)) {
JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu at %#08x\n",
rc, sizeof(rx), readlen, offset);
return rc ? rc : -EIO;
}
crc = crc32(0, &rx, sizeof(rx) - 4);
if (crc != je32_to_cpu(rx.node_crc)) {
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;
return -EIO;
}
totlen = PAD(sizeof(rx) + rx.name_len + 1 + je16_to_cpu(rx.value_len));
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",
offset, 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);
xd->flags |= JFFS2_XFLAGS_INVALID;
return -EIO;
}
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);
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);
}
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) {
JFFS2_WARNING("jffs2_flash_read() returned %d, request=%d, readlen=%zu, at %#08x\n",
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) {
JFFS2_WARNING("node CRC failed (JFFS2_NODETYPE_XREF)"
" at %#08x, read: 0x%08x calculated: 0x%08x\n",
ref_offset(xd->node), xd->data_crc, crc);
kfree(data);
xd->flags |= JFFS2_XFLAGS_INVALID;
return -EIO;
}
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;
BUG_ON(xd->flags & JFFS2_XFLAGS_DEAD);
if (xd->xname)
return 0;
if (xd->flags & JFFS2_XFLAGS_INVALID)
return -EIO;
if (unlikely(is_xattr_datum_unchecked(c, xd)))
rc = do_verify_xattr_datum(c, xd);
if (!rc)
rc = do_load_xattr_datum(c, xd);
return rc;
}
static int save_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
/* must be called under down_write(xattr_sem) */
struct jffs2_raw_xattr rx;
struct kvec vecs[2];
size_t length;
int rc, totlen;
uint32_t phys_ofs = write_ofs(c);
BUG_ON(!xd->xname);
BUG_ON(xd->flags & (JFFS2_XFLAGS_DEAD|JFFS2_XFLAGS_INVALID));
vecs[0].iov_base = ℞
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;
/* Setup raw-xattr */
memset(&rx, 0, sizeof(rx));
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);
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));
rx.node_crc = cpu_to_je32(crc32(0, &rx, sizeof(struct jffs2_raw_xattr) - 4));
rc = jffs2_flash_writev(c, vecs, 2, phys_ofs, &length, 0);
if (rc || totlen != length) {
JFFS2_WARNING("jffs2_flash_writev()=%d, req=%u, wrote=%zu, at %#08x\n",
rc, totlen, length, phys_ofs);
rc = rc ? rc : -EIO;
if (length)
jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(totlen), NULL);
return rc;
}
/* success */
jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(totlen), (void *)xd);
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,
const char *xvalue, int xsize)
{
/* 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)) {
atomic_inc(&xd->refcnt);
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);
atomic_set(&xd->refcnt, 1);
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);
rc = save_xattr_datum(c, xd);
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;
}
static void unrefer_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
{
/* must be called under down_write(xattr_sem) */
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);
dbg_xattr("xdatum(xid=%u, version=%u) was removed.\n",
xd->xid, xd->version);
}
}
/* -------- xref related functions ------------------
* 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.
* save_xattr_ref(c, ref)
* is used to write xref to medium. If delete marker is marked, it write
* a delete marker of xref into medium.
* create_xattr_ref(c, ic, xd)
* is used to create a new xref and write to medium.
* 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.
* 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.
* check_xattr_ref_inode(c, ic)
* is used to confirm inode does not have duplicate xattr name/value pair.
* -------------------------------------------------- */
static int verify_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
{
struct jffs2_eraseblock *jeb;
struct jffs2_raw_node_ref *raw;
struct jffs2_raw_xref rr;
size_t readlen;
uint32_t crc, offset, totlen;
int rc;
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);
rc = jffs2_flash_read(c, offset, sizeof(rr), &readlen, (char *)&rr);
if (rc || sizeof(rr) != readlen) {
JFFS2_WARNING("jffs2_flash_read()=%d, req=%zu, read=%zu, at %#08x\n",
rc, sizeof(rr), readlen, offset);
return rc ? rc : -EIO;
}
/* obsolete node */
crc = crc32(0, &rr, sizeof(rr) - 4);
if (crc != je32_to_cpu(rr.node_crc)) {
JFFS2_ERROR("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
offset, je32_to_cpu(rr.node_crc), crc);
return -EIO;
}
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, "
"nodetype=%#04x/%#04x, totlen=%u/%zu\n",
offset, je16_to_cpu(rr.magic), JFFS2_MAGIC_BITMASK,
je16_to_cpu(rr.nodetype), JFFS2_NODETYPE_XREF,
je32_to_cpu(rr.totlen), PAD(sizeof(rr)));
return -EIO;
}
ref->ino = je32_to_cpu(rr.ino);
ref->xid = je32_to_cpu(rr.xid);
ref->xseqno = je32_to_cpu(rr.xseqno);
if (ref->xseqno > c->highest_xseqno)
c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
spin_lock(&c->erase_completion_lock);
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);
}
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;
}
static int save_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
{
/* must be called under down_write(xattr_sem) */
struct jffs2_raw_xref rr;
size_t length;
uint32_t xseqno, phys_ofs = write_ofs(c);
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));
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);
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) {
JFFS2_WARNING("jffs2_flash_write() returned %d, request=%zu, retlen=%zu, at %#08x\n",
ret, sizeof(rr), length, phys_ofs);
ret = ret ? ret : -EIO;
if (length)
jffs2_add_physical_node_ref(c, phys_ofs | REF_OBSOLETE, PAD(sizeof(rr)), NULL);
return ret;
}
/* success */
ref->xseqno = xseqno;
jffs2_add_physical_node_ref(c, phys_ofs | REF_PRISTINE, PAD(sizeof(rr)), (void *)ref);
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,
struct jffs2_xattr_datum *xd)
{
/* 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;
ret = save_xattr_ref(c, ref);
if (ret) {
jffs2_free_xattr_ref(ref);
return ERR_PTR(ret);
}
/* Chain to inode */
ref->next = ic->xref;
ic->xref = ref;
return ref; /* success */
}
static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *ref)
{
/* must be called under down_write(xattr_sem) */
struct jffs2_xattr_datum *xd;
xd = ref->xd;
ref->xseqno |= XREF_DELETE_MARKER;
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);
dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
ref->ino, ref->xid, ref->xseqno);
unrefer_xattr_datum(c, xd);
}
void jffs2_xattr_delete_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
{
/* It's called from jffs2_evict_inode() on inode removing.
When an inode with XATTR is removed, those XATTRs must be removed. */
struct jffs2_xattr_ref *ref, *_ref;
if (!ic || ic->pino_nlink > 0)
return;
down_write(&c->xattr_sem);
for (ref = ic->xref; ref; ref = _ref) {
_ref = ref->next;
delete_xattr_ref(c, ref);
}
ic->xref = NULL;
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);
for (ref = ic->xref; ref; ref = _ref) {
_ref = ref->next;
xd = ref->xd;
if (atomic_dec_and_test(&xd->refcnt)) {
unload_xattr_datum(c, xd);
jffs2_free_xattr_datum(xd);
}
jffs2_free_xattr_ref(ref);
}
ic->xref = NULL;
up_write(&c->xattr_sem);
}
static int check_xattr_ref_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
{
/* success of check_xattr_ref_inode() means that inode (ic) dose not have
* duplicate name/value pairs. If duplicate name/value pair would be found,
* one will be removed.
*/
struct jffs2_xattr_ref *ref, *cmp, **pref, **pcmp;
int rc = 0;
if (likely(ic->flags & INO_FLAGS_XATTR_CHECKED))
return 0;
down_write(&c->xattr_sem);
retry:
rc = 0;
for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
if (!ref->xd->xname) {
rc = load_xattr_datum(c, ref->xd);
if (unlikely(rc > 0)) {
*pref = ref->next;
delete_xattr_ref(c, ref);
goto retry;
} else if (unlikely(rc < 0))
goto out;
}
for (cmp=ref->next, pcmp=&ref->next; cmp; pcmp=&cmp->next, cmp=cmp->next) {
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)) {
*pcmp = cmp->next;
delete_xattr_ref(c, cmp);
goto retry;
} else if (unlikely(rc < 0))
goto out;
}
if (ref->xd->xprefix == cmp->xd->xprefix
&& !strcmp(ref->xd->xname, cmp->xd->xname)) {
if (ref->xseqno > cmp->xseqno) {
*pcmp = cmp->next;
delete_xattr_ref(c, cmp);
} else {
*pref = ref->next;
delete_xattr_ref(c, ref);
}
goto retry;
}
}
}
ic->flags |= INO_FLAGS_XATTR_CHECKED;
out:
up_write(&c->xattr_sem);
return rc;
}
/* -------- 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);
INIT_LIST_HEAD(&c->xattr_dead_list);
c->xref_dead_list = NULL;
c->xref_temp = NULL;
init_rwsem(&c->xattr_sem);
c->highest_xid = 0;
c->highest_xseqno = 0;
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;
for (ref=c->xref_temp; ref; ref = _ref) {
_ref = ref->next;
jffs2_free_xattr_ref(ref);
}
for (ref=c->xref_dead_list; ref; ref = _ref) {
_ref = ref->next;
jffs2_free_xattr_ref(ref);
}
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);
}
}
list_for_each_entry_safe(xd, _xd, &c->xattr_dead_list, xindex) {
list_del(&xd->xindex);
jffs2_free_xattr_datum(xd);
}
list_for_each_entry_safe(xd, _xd, &c->xattr_unchecked, xindex) {
list_del(&xd->xindex);
jffs2_free_xattr_datum(xd);
}
}
#define XREF_TMPHASH_SIZE (128)
void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
{
struct jffs2_xattr_ref *ref, *_ref;
struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];
struct jffs2_xattr_datum *xd, *_xd;
struct jffs2_inode_cache *ic;
struct jffs2_raw_node_ref *raw;
int i, xdatum_count = 0, xdatum_unchecked_count = 0, xref_count = 0;
int xdatum_orphan_count = 0, xref_orphan_count = 0, xref_dead_count = 0;
BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));
/* Phase.1 : Merge same xref */
for (i=0; i < XREF_TMPHASH_SIZE; i++)
xref_tmphash[i] = NULL;
for (ref=c->xref_temp; ref; ref=_ref) {
struct jffs2_xattr_ref *tmp;
_ref = ref->next;
if (ref_flags(ref->node) != REF_PRISTINE) {
if (verify_xattr_ref(c, ref)) {
BUG_ON(ref->node->next_in_ino != (void *)ref);
ref->node->next_in_ino = NULL;
jffs2_mark_node_obsolete(c, ref->node);
jffs2_free_xattr_ref(ref);
continue;
}
}
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;
}
jffs2_free_xattr_ref(ref);
continue;
} else {
ref->next = xref_tmphash[i];
xref_tmphash[i] = ref;
}
}
c->xref_temp = NULL;
/* Phase.2 : Bind xref with inode_cache and xattr_datum */
for (i=0; i < XREF_TMPHASH_SIZE; i++) {
for (ref=xref_tmphash[i]; ref; ref=_ref) {
xref_count++;
_ref = ref->next;
if (is_xattr_ref_dead(ref)) {
ref->next = c->xref_dead_list;
c->xref_dead_list = ref;
xref_dead_count++;
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);
if (!xd || !ic || !ic->pino_nlink) {
dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) is orphan.\n",
ref->ino, ref->xid, ref->xseqno);
ref->xseqno |= XREF_DELETE_MARKER;
ref->next = c->xref_dead_list;
c->xref_dead_list = ref;
xref_orphan_count++;
continue;
}
ref->xd = xd;
ref->ic = ic;
atomic_inc(&xd->refcnt);
ref->next = ic->xref;
ic->xref = ref;
}
}
/* Phase.3 : Link unchecked xdatum to xattr_unchecked list */
for (i=0; i < XATTRINDEX_HASHSIZE; i++) {
list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
xdatum_count++;
list_del_init(&xd->xindex);
if (!atomic_read(&xd->refcnt)) {
dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
xd->xid, xd->version);
xd->flags |= JFFS2_XFLAGS_DEAD;
list_add(&xd->xindex, &c->xattr_unchecked);
xdatum_orphan_count++;
continue;
}
if (is_xattr_datum_unchecked(c, xd)) {
dbg_xattr("unchecked xdatum(xid=%u, version=%u)\n",
xd->xid, xd->version);
list_add(&xd->xindex, &c->xattr_unchecked);
xdatum_unchecked_count++;
}
}
}
/* build complete */
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);
}
struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c,
uint32_t xid, uint32_t version)
{
struct jffs2_xattr_datum *xd;
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]);
}
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.
* -------------------------------------------------- */
const struct xattr_handler *jffs2_xattr_handlers[] = {
&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
};
static const struct xattr_handler *xprefix_to_handler(int xprefix) {
const struct xattr_handler *ret;
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;
struct jffs2_xattr_ref *ref, **pref;
struct jffs2_xattr_datum *xd;
const struct xattr_handler *xhandle;
ssize_t len, rc;
int retry = 0;
rc = check_xattr_ref_inode(c, ic);
if (unlikely(rc))
return rc;
down_read(&c->xattr_sem);
retry:
len = 0;
for (ref=ic->xref, pref=&ic->xref; ref; pref=&ref->next, ref=ref->next) {
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)) {
*pref = ref->next;
delete_xattr_ref(c, ref);
goto retry;
} else if (unlikely(rc < 0))
goto out;
}
}
xhandle = xprefix_to_handler(xd->xprefix);
if (!xhandle)
continue;
if (buffer) {
rc = xhandle->list(dentry, buffer+len, size-len,
xd->xname, xd->name_len, xd->flags);
} else {
rc = xhandle->list(dentry, NULL, 0, xd->xname,
xd->name_len, xd->flags);
}
if (rc < 0)
goto out;