blob: 458030bfccb880ad768c7e9aa14d564af37d9f16 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* (a large amount of code was adapted from Linux kernel. )
*
* Copyright (C) 2018-2019 HUAWEI, Inc.
* https://www.huawei.com/
* Created by Gao Xiang <gaoxiang25@huawei.com>
* Modified by Huang Jianan <huangjianan@oppo.com>
*/
#include "erofs/io.h"
#include "erofs/print.h"
int z_erofs_fill_inode(struct erofs_inode *vi)
{
if (!erofs_sb_has_big_pcluster() &&
vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY) {
vi->z_advise = 0;
vi->z_algorithmtype[0] = 0;
vi->z_algorithmtype[1] = 0;
vi->z_logical_clusterbits = LOG_BLOCK_SIZE;
vi->flags |= EROFS_I_Z_INITED;
}
return 0;
}
static int z_erofs_fill_inode_lazy(struct erofs_inode *vi)
{
int ret;
erofs_off_t pos;
struct z_erofs_map_header *h;
char buf[sizeof(struct z_erofs_map_header)];
if (vi->flags & EROFS_I_Z_INITED)
return 0;
DBG_BUGON(!erofs_sb_has_big_pcluster() &&
vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY);
pos = round_up(iloc(vi->nid) + vi->inode_isize + vi->xattr_isize, 8);
ret = dev_read(buf, pos, sizeof(buf));
if (ret < 0)
return -EIO;
h = (struct z_erofs_map_header *)buf;
vi->z_advise = le16_to_cpu(h->h_advise);
vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX) {
erofs_err("unknown compression format %u for nid %llu",
vi->z_algorithmtype[0], (unsigned long long)vi->nid);
return -EOPNOTSUPP;
}
vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7);
if (vi->datalayout == EROFS_INODE_FLAT_COMPRESSION &&
!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^
!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
erofs_err("big pcluster head1/2 of compact indexes should be consistent for nid %llu",
vi->nid * 1ULL);
return -EFSCORRUPTED;
}
vi->flags |= EROFS_I_Z_INITED;
return 0;
}
struct z_erofs_maprecorder {
struct erofs_inode *inode;
struct erofs_map_blocks *map;
void *kaddr;
unsigned long lcn;
/* compression extent information gathered */
u8 type;
u16 clusterofs;
u16 delta[2];
erofs_blk_t pblk, compressedlcs;
};
static int z_erofs_reload_indexes(struct z_erofs_maprecorder *m,
erofs_blk_t eblk)
{
int ret;
struct erofs_map_blocks *const map = m->map;
char *mpage = map->mpage;
if (map->index == eblk)
return 0;
ret = blk_read(mpage, eblk, 1);
if (ret < 0)
return -EIO;
map->index = eblk;
return 0;
}
static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
unsigned long lcn)
{
struct erofs_inode *const vi = m->inode;
const erofs_off_t ibase = iloc(vi->nid);
const erofs_off_t pos =
Z_EROFS_VLE_LEGACY_INDEX_ALIGN(ibase + vi->inode_isize +
vi->xattr_isize) +
lcn * sizeof(struct z_erofs_vle_decompressed_index);
struct z_erofs_vle_decompressed_index *di;
unsigned int advise, type;
int err;
err = z_erofs_reload_indexes(m, erofs_blknr(pos));
if (err)
return err;
m->lcn = lcn;
di = m->kaddr + erofs_blkoff(pos);
advise = le16_to_cpu(di->di_advise);
type = (advise >> Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT) &
((1 << Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) - 1);
switch (type) {
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
m->clusterofs = 1 << vi->z_logical_clusterbits;
m->delta[0] = le16_to_cpu(di->di_u.delta[0]);
if (m->delta[0] & Z_EROFS_VLE_DI_D0_CBLKCNT) {
if (!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
m->compressedlcs = m->delta[0] &
~Z_EROFS_VLE_DI_D0_CBLKCNT;
m->delta[0] = 1;
}
m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
break;
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
m->clusterofs = le16_to_cpu(di->di_clusterofs);
m->pblk = le32_to_cpu(di->di_u.blkaddr);
break;
default:
DBG_BUGON(1);
return -EOPNOTSUPP;
}
m->type = type;
return 0;
}
static unsigned int decode_compactedbits(unsigned int lobits,
unsigned int lomask,
u8 *in, unsigned int pos, u8 *type)
{
const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7);
const unsigned int lo = v & lomask;
*type = (v >> lobits) & 3;
return lo;
}
static int unpack_compacted_index(struct z_erofs_maprecorder *m,
unsigned int amortizedshift,
unsigned int eofs)
{
struct erofs_inode *const vi = m->inode;
const unsigned int lclusterbits = vi->z_logical_clusterbits;
const unsigned int lomask = (1 << lclusterbits) - 1;
unsigned int vcnt, base, lo, encodebits, nblk;
int i;
u8 *in, type;
bool big_pcluster;
if (1 << amortizedshift == 4)
vcnt = 2;
else if (1 << amortizedshift == 2 && lclusterbits == 12)
vcnt = 16;
else
return -EOPNOTSUPP;
big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
base = round_down(eofs, vcnt << amortizedshift);
in = m->kaddr + base;
i = (eofs - base) >> amortizedshift;
lo = decode_compactedbits(lclusterbits, lomask,
in, encodebits * i, &type);
m->type = type;
if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
m->clusterofs = 1 << lclusterbits;
if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
if (!big_pcluster) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
m->compressedlcs = lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
m->delta[0] = 1;
return 0;
} else if (i + 1 != (int)vcnt) {
m->delta[0] = lo;
return 0;
}
/*
* since the last lcluster in the pack is special,
* of which lo saves delta[1] rather than delta[0].
* Hence, get delta[0] by the previous lcluster indirectly.
*/
lo = decode_compactedbits(lclusterbits, lomask,
in, encodebits * (i - 1), &type);
if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
lo = 0;
else if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT)
lo = 1;
m->delta[0] = lo + 1;
return 0;
}
m->clusterofs = lo;
m->delta[0] = 0;
/* figout out blkaddr (pblk) for HEAD lclusters */
if (!big_pcluster) {
nblk = 1;
while (i > 0) {
--i;
lo = decode_compactedbits(lclusterbits, lomask,
in, encodebits * i, &type);
if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
i -= lo;
if (i >= 0)
++nblk;
}
} else {
nblk = 0;
while (i > 0) {
--i;
lo = decode_compactedbits(lclusterbits, lomask,
in, encodebits * i, &type);
if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
--i;
nblk += lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
continue;
}
if (lo == 1) {
DBG_BUGON(1);
/* --i; ++nblk; continue; */
return -EFSCORRUPTED;
}
i -= lo - 2;
continue;
}
++nblk;
}
}
in += (vcnt << amortizedshift) - sizeof(__le32);
m->pblk = le32_to_cpu(*(__le32 *)in) + nblk;
return 0;
}
static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
unsigned long lcn)
{
struct erofs_inode *const vi = m->inode;
const unsigned int lclusterbits = vi->z_logical_clusterbits;
const erofs_off_t ebase = round_up(iloc(vi->nid) + vi->inode_isize +
vi->xattr_isize, 8) +
sizeof(struct z_erofs_map_header);
const unsigned int totalidx = DIV_ROUND_UP(vi->i_size, EROFS_BLKSIZ);
unsigned int compacted_4b_initial, compacted_2b;
unsigned int amortizedshift;
erofs_off_t pos;
int err;
if (lclusterbits != 12)
return -EOPNOTSUPP;
if (lcn >= totalidx)
return -EINVAL;
m->lcn = lcn;
/* used to align to 32-byte (compacted_2b) alignment */
compacted_4b_initial = (32 - ebase % 32) / 4;
if (compacted_4b_initial == 32 / 4)
compacted_4b_initial = 0;
if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
else
compacted_2b = 0;
pos = ebase;
if (lcn < compacted_4b_initial) {
amortizedshift = 2;
goto out;
}
pos += compacted_4b_initial * 4;
lcn -= compacted_4b_initial;
if (lcn < compacted_2b) {
amortizedshift = 1;
goto out;
}
pos += compacted_2b * 2;
lcn -= compacted_2b;
amortizedshift = 2;
out:
pos += lcn * (1 << amortizedshift);
err = z_erofs_reload_indexes(m, erofs_blknr(pos));
if (err)
return err;
return unpack_compacted_index(m, amortizedshift, erofs_blkoff(pos));
}
static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m,
unsigned int lcn)
{
const unsigned int datamode = m->inode->datalayout;
if (datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
return legacy_load_cluster_from_disk(m, lcn);
if (datamode == EROFS_INODE_FLAT_COMPRESSION)
return compacted_load_cluster_from_disk(m, lcn);
return -EINVAL;
}
static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
unsigned int lookback_distance)
{
struct erofs_inode *const vi = m->inode;
struct erofs_map_blocks *const map = m->map;
const unsigned int lclusterbits = vi->z_logical_clusterbits;
unsigned long lcn = m->lcn;
int err;
if (lcn < lookback_distance) {
erofs_err("bogus lookback distance @ nid %llu",
(unsigned long long)vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
/* load extent head logical cluster if needed */
lcn -= lookback_distance;
err = z_erofs_load_cluster_from_disk(m, lcn);
if (err)
return err;
switch (m->type) {
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
if (!m->delta[0]) {
erofs_err("invalid lookback distance 0 @ nid %llu",
(unsigned long long)vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
return z_erofs_extent_lookback(m, m->delta[0]);
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
map->m_flags &= ~EROFS_MAP_ZIPPED;
/* fallthrough */
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
map->m_la = (lcn << lclusterbits) | m->clusterofs;
break;
default:
erofs_err("unknown type %u @ lcn %lu of nid %llu",
m->type, lcn, (unsigned long long)vi->nid);
DBG_BUGON(1);
return -EOPNOTSUPP;
}
return 0;
}
static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
unsigned int initial_lcn)
{
struct erofs_inode *const vi = m->inode;
struct erofs_map_blocks *const map = m->map;
const unsigned int lclusterbits = vi->z_logical_clusterbits;
unsigned long lcn;
int err;
DBG_BUGON(m->type != Z_EROFS_VLE_CLUSTER_TYPE_PLAIN &&
m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD);
if (!(map->m_flags & EROFS_MAP_ZIPPED) ||
!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
map->m_plen = 1 << lclusterbits;
return 0;
}
lcn = m->lcn + 1;
if (m->compressedlcs)
goto out;
err = z_erofs_load_cluster_from_disk(m, lcn);
if (err)
return err;
/*
* If the 1st NONHEAD lcluster has already been handled initially w/o
* valid compressedlcs, which means at least it mustn't be CBLKCNT, or
* an internal implemenatation error is detected.
*
* The following code can also handle it properly anyway, but let's
* BUG_ON in the debugging mode only for developers to notice that.
*/
DBG_BUGON(lcn == initial_lcn &&
m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD);
switch (m->type) {
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
/*
* if the 1st NONHEAD lcluster is actually PLAIN or HEAD type
* rather than CBLKCNT, it's a 1 lcluster-sized pcluster.
*/
m->compressedlcs = 1;
break;
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
if (m->delta[0] != 1)
goto err_bonus_cblkcnt;
if (m->compressedlcs)
break;
/* fallthrough */
default:
erofs_err("cannot found CBLKCNT @ lcn %lu of nid %llu",
lcn, vi->nid | 0ULL);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
out:
map->m_plen = m->compressedlcs << lclusterbits;
return 0;
err_bonus_cblkcnt:
erofs_err("bogus CBLKCNT @ lcn %lu of nid %llu",
lcn, vi->nid | 0ULL);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
int z_erofs_map_blocks_iter(struct erofs_inode *vi,
struct erofs_map_blocks *map)
{
struct z_erofs_maprecorder m = {
.inode = vi,
.map = map,
.kaddr = map->mpage,
};
int err = 0;
unsigned int lclusterbits, endoff;
unsigned long initial_lcn;
unsigned long long ofs, end;
/* when trying to read beyond EOF, leave it unmapped */
if (map->m_la >= vi->i_size) {
map->m_llen = map->m_la + 1 - vi->i_size;
map->m_la = vi->i_size;
map->m_flags = 0;
goto out;
}
err = z_erofs_fill_inode_lazy(vi);
if (err)
goto out;
lclusterbits = vi->z_logical_clusterbits;
ofs = map->m_la;
initial_lcn = ofs >> lclusterbits;
endoff = ofs & ((1 << lclusterbits) - 1);
err = z_erofs_load_cluster_from_disk(&m, initial_lcn);
if (err)
goto out;
map->m_flags = EROFS_MAP_ZIPPED; /* by default, compressed */
end = (m.lcn + 1ULL) << lclusterbits;
switch (m.type) {
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
if (endoff >= m.clusterofs)
map->m_flags &= ~EROFS_MAP_ZIPPED;
/* fallthrough */
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
if (endoff >= m.clusterofs) {
map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
break;
}
/* m.lcn should be >= 1 if endoff < m.clusterofs */
if (!m.lcn) {
erofs_err("invalid logical cluster 0 at nid %llu",
(unsigned long long)vi->nid);
err = -EFSCORRUPTED;
goto out;
}
end = (m.lcn << lclusterbits) | m.clusterofs;
map->m_flags |= EROFS_MAP_FULL_MAPPED;
m.delta[0] = 1;
/* fallthrough */
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
/* get the correspoinding first chunk */
err = z_erofs_extent_lookback(&m, m.delta[0]);
if (err)
goto out;
break;
default:
erofs_err("unknown type %u @ offset %llu of nid %llu",
m.type, ofs, (unsigned long long)vi->nid);
err = -EOPNOTSUPP;
goto out;
}
map->m_llen = end - map->m_la;
map->m_pa = blknr_to_addr(m.pblk);
err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
if (err)
goto out;
map->m_flags |= EROFS_MAP_MAPPED;
out:
erofs_dbg("m_la %" PRIu64 " m_pa %" PRIu64 " m_llen %" PRIu64 " m_plen %" PRIu64 " m_flags 0%o",
map->m_la, map->m_pa,
map->m_llen, map->m_plen, map->m_flags);
DBG_BUGON(err < 0 && err != -ENOMEM);
return err;
}