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OpenCloudOS-Kernel/fs/erofs/zmap.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2018-2019 HUAWEI, Inc.
* https://www.huawei.com/
*/
#include "internal.h"
#include <asm/unaligned.h>
#include <trace/events/erofs.h>
static int z_erofs_do_map_blocks(struct inode *inode,
struct erofs_map_blocks *map,
int flags);
int z_erofs_fill_inode(struct inode *inode)
{
struct erofs_inode *const vi = EROFS_I(inode);
struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
if (!erofs_sb_has_big_pcluster(sbi) &&
!erofs_sb_has_ztailpacking(sbi) &&
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;
set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
}
inode->i_mapping->a_ops = &z_erofs_aops;
return 0;
}
static int z_erofs_fill_inode_lazy(struct inode *inode)
{
struct erofs_inode *const vi = EROFS_I(inode);
struct super_block *const sb = inode->i_sb;
int err, headnr;
erofs_off_t pos;
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
void *kaddr;
struct z_erofs_map_header *h;
if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) {
/*
* paired with smp_mb() at the end of the function to ensure
* fields will only be observed after the bit is set.
*/
smp_mb();
return 0;
}
if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_Z_BIT, TASK_KILLABLE))
return -ERESTARTSYS;
err = 0;
if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags))
goto out_unlock;
DBG_BUGON(!erofs_sb_has_big_pcluster(EROFS_SB(sb)) &&
!erofs_sb_has_ztailpacking(EROFS_SB(sb)) &&
vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY);
pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
vi->xattr_isize, 8);
kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos),
EROFS_KMAP_ATOMIC);
if (IS_ERR(kaddr)) {
err = PTR_ERR(kaddr);
goto out_unlock;
}
h = kaddr + erofs_blkoff(pos);
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;
headnr = 0;
if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX ||
vi->z_algorithmtype[++headnr] >= Z_EROFS_COMPRESSION_MAX) {
erofs_err(sb, "unknown HEAD%u format %u for nid %llu, please upgrade kernel",
headnr + 1, vi->z_algorithmtype[headnr], vi->nid);
err = -EOPNOTSUPP;
goto unmap_done;
}
vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7);
if (!erofs_sb_has_big_pcluster(EROFS_SB(sb)) &&
vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 |
Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
erofs_err(sb, "per-inode big pcluster without sb feature for nid %llu",
vi->nid);
err = -EFSCORRUPTED;
goto unmap_done;
}
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(sb, "big pcluster head1/2 of compact indexes should be consistent for nid %llu",
vi->nid);
err = -EFSCORRUPTED;
goto unmap_done;
}
unmap_done:
erofs_put_metabuf(&buf);
if (err)
goto out_unlock;
if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) {
struct erofs_map_blocks map = {
.buf = __EROFS_BUF_INITIALIZER
};
vi->z_idata_size = le16_to_cpu(h->h_idata_size);
err = z_erofs_do_map_blocks(inode, &map,
EROFS_GET_BLOCKS_FINDTAIL);
erofs_put_metabuf(&map.buf);
if (!map.m_plen ||
erofs_blkoff(map.m_pa) + map.m_plen > EROFS_BLKSIZ) {
erofs_err(sb, "invalid tail-packing pclustersize %llu",
map.m_plen);
err = -EFSCORRUPTED;
}
if (err < 0)
goto out_unlock;
}
/* paired with smp_mb() at the beginning of the function */
smp_mb();
set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
out_unlock:
clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags);
return err;
}
struct z_erofs_maprecorder {
struct inode *inode;
struct erofs_map_blocks *map;
void *kaddr;
unsigned long lcn;
/* compression extent information gathered */
u8 type, headtype;
u16 clusterofs;
u16 delta[2];
erofs_blk_t pblk, compressedblks;
erofs_off_t nextpackoff;
};
static int z_erofs_reload_indexes(struct z_erofs_maprecorder *m,
erofs_blk_t eblk)
{
struct super_block *const sb = m->inode->i_sb;
m->kaddr = erofs_read_metabuf(&m->map->buf, sb, eblk,
EROFS_KMAP_ATOMIC);
if (IS_ERR(m->kaddr))
return PTR_ERR(m->kaddr);
return 0;
}
static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
unsigned long lcn)
{
struct inode *const inode = m->inode;
struct erofs_inode *const vi = EROFS_I(inode);
const erofs_off_t ibase = iloc(EROFS_I_SB(inode), 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->nextpackoff = pos + sizeof(struct z_erofs_vle_decompressed_index);
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 |
Z_EROFS_ADVISE_BIG_PCLUSTER_2))) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
m->compressedblks = 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_HEAD1:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD2:
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 get_compacted_la_distance(unsigned int lclusterbits,
unsigned int encodebits,
unsigned int vcnt, u8 *in, int i)
{
const unsigned int lomask = (1 << lclusterbits) - 1;
unsigned int lo, d1 = 0;
u8 type;
DBG_BUGON(i >= vcnt);
do {
lo = decode_compactedbits(lclusterbits, lomask,
in, encodebits * i, &type);
if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
return d1;
++d1;
} while (++i < vcnt);
/* vcnt - 1 (Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) item */
if (!(lo & Z_EROFS_VLE_DI_D0_CBLKCNT))
d1 += lo - 1;
return d1;
}
static int unpack_compacted_index(struct z_erofs_maprecorder *m,
unsigned int amortizedshift,
erofs_off_t pos, bool lookahead)
{
struct erofs_inode *const vi = EROFS_I(m->inode);
const unsigned int lclusterbits = vi->z_logical_clusterbits;
const unsigned int lomask = (1 << lclusterbits) - 1;
unsigned int vcnt, base, lo, encodebits, nblk, eofs;
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;
/* it doesn't equal to round_up(..) */
m->nextpackoff = round_down(pos, vcnt << amortizedshift) +
(vcnt << amortizedshift);
big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
eofs = erofs_blkoff(pos);
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;
/* figure out lookahead_distance: delta[1] if needed */
if (lookahead)
m->delta[1] = get_compacted_la_distance(lclusterbits,
encodebits, vcnt, in, i);
if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
if (!big_pcluster) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
m->compressedblks = 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;
}
/* bigpcluster shouldn't have plain d0 == 1 */
if (lo <= 1) {
DBG_BUGON(1);
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, bool lookahead)
{
struct inode *const inode = m->inode;
struct erofs_inode *const vi = EROFS_I(inode);
const unsigned int lclusterbits = vi->z_logical_clusterbits;
const erofs_off_t ebase = ALIGN(iloc(EROFS_I_SB(inode), vi->nid) +
vi->inode_isize + vi->xattr_isize, 8) +
sizeof(struct z_erofs_map_header);
const unsigned int totalidx = DIV_ROUND_UP(inode->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_4b_initial < totalidx)
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, pos, lookahead);
}
static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m,
unsigned int lcn, bool lookahead)
{
const unsigned int datamode = EROFS_I(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, lookahead);
return -EINVAL;
}
static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
unsigned int lookback_distance)
{
struct erofs_inode *const vi = EROFS_I(m->inode);
const unsigned int lclusterbits = vi->z_logical_clusterbits;
while (m->lcn >= lookback_distance) {
unsigned long lcn = m->lcn - lookback_distance;
int err;
/* load extent head logical cluster if needed */
err = z_erofs_load_cluster_from_disk(m, lcn, false);
if (err)
return err;
switch (m->type) {
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
if (!m->delta[0]) {
erofs_err(m->inode->i_sb,
"invalid lookback distance 0 @ nid %llu",
vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
lookback_distance = m->delta[0];
continue;
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD1:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD2:
m->headtype = m->type;
m->map->m_la = (lcn << lclusterbits) | m->clusterofs;
return 0;
default:
erofs_err(m->inode->i_sb,
"unknown type %u @ lcn %lu of nid %llu",
m->type, lcn, vi->nid);
DBG_BUGON(1);
return -EOPNOTSUPP;
}
}
erofs_err(m->inode->i_sb, "bogus lookback distance @ nid %llu",
vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
unsigned int initial_lcn)
{
struct erofs_inode *const vi = EROFS_I(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_HEAD1 &&
m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD2);
DBG_BUGON(m->type != m->headtype);
if (m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN ||
((m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD1) &&
!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) ||
((m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2) &&
!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2))) {
map->m_plen = 1ULL << lclusterbits;
return 0;
}
lcn = m->lcn + 1;
if (m->compressedblks)
goto out;
err = z_erofs_load_cluster_from_disk(m, lcn, false);
if (err)
return err;
/*
* If the 1st NONHEAD lcluster has already been handled initially w/o
* valid compressedblks, 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_HEAD1:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD2:
/*
* if the 1st NONHEAD lcluster is actually PLAIN or HEAD type
* rather than CBLKCNT, it's a 1 lcluster-sized pcluster.
*/
m->compressedblks = 1 << (lclusterbits - LOG_BLOCK_SIZE);
break;
case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
if (m->delta[0] != 1)
goto err_bonus_cblkcnt;
if (m->compressedblks)
break;
fallthrough;
default:
erofs_err(m->inode->i_sb,
"cannot found CBLKCNT @ lcn %lu of nid %llu",
lcn, vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
out:
map->m_plen = (u64)m->compressedblks << LOG_BLOCK_SIZE;
return 0;
err_bonus_cblkcnt:
erofs_err(m->inode->i_sb,
"bogus CBLKCNT @ lcn %lu of nid %llu",
lcn, vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
{
struct inode *inode = m->inode;
struct erofs_inode *vi = EROFS_I(inode);
struct erofs_map_blocks *map = m->map;
unsigned int lclusterbits = vi->z_logical_clusterbits;
u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits;
int err;
do {
/* handle the last EOF pcluster (no next HEAD lcluster) */
if ((lcn << lclusterbits) >= inode->i_size) {
map->m_llen = inode->i_size - map->m_la;
return 0;
}
err = z_erofs_load_cluster_from_disk(m, lcn, true);
if (err)
return err;
if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
DBG_BUGON(!m->delta[1] &&
m->clusterofs != 1 << lclusterbits);
} else if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN ||
m->type == Z_EROFS_VLE_CLUSTER_TYPE_HEAD1 ||
m->type == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2) {
/* go on until the next HEAD lcluster */
if (lcn != headlcn)
break;
m->delta[1] = 1;
} else {
erofs_err(inode->i_sb, "unknown type %u @ lcn %llu of nid %llu",
m->type, lcn, vi->nid);
DBG_BUGON(1);
return -EOPNOTSUPP;
}
lcn += m->delta[1];
} while (m->delta[1]);
map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la;
return 0;
}
static int z_erofs_do_map_blocks(struct inode *inode,
struct erofs_map_blocks *map,
int flags)
{
struct erofs_inode *const vi = EROFS_I(inode);
bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER;
struct z_erofs_maprecorder m = {
.inode = inode,
.map = map,
};
int err = 0;
unsigned int lclusterbits, endoff;
unsigned long initial_lcn;
unsigned long long ofs, end;
lclusterbits = vi->z_logical_clusterbits;
ofs = flags & EROFS_GET_BLOCKS_FINDTAIL ? inode->i_size - 1 : map->m_la;
initial_lcn = ofs >> lclusterbits;
endoff = ofs & ((1 << lclusterbits) - 1);
err = z_erofs_load_cluster_from_disk(&m, initial_lcn, false);
if (err)
goto unmap_out;
if (ztailpacking && (flags & EROFS_GET_BLOCKS_FINDTAIL))
vi->z_idataoff = m.nextpackoff;
map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED;
end = (m.lcn + 1ULL) << lclusterbits;
switch (m.type) {
case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD1:
case Z_EROFS_VLE_CLUSTER_TYPE_HEAD2:
if (endoff >= m.clusterofs) {
m.headtype = m.type;
map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
/*
* For ztailpacking files, in order to inline data more
* effectively, special EOF lclusters are now supported
* which can have three parts at most.
*/
if (ztailpacking && end > inode->i_size)
end = inode->i_size;
break;
}
/* m.lcn should be >= 1 if endoff < m.clusterofs */
if (!m.lcn) {
erofs_err(inode->i_sb,
"invalid logical cluster 0 at nid %llu",
vi->nid);
err = -EFSCORRUPTED;
goto unmap_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 corresponding first chunk */
err = z_erofs_extent_lookback(&m, m.delta[0]);
if (err)
goto unmap_out;
break;
default:
erofs_err(inode->i_sb,
"unknown type %u @ offset %llu of nid %llu",
m.type, ofs, vi->nid);
err = -EOPNOTSUPP;
goto unmap_out;
}
map->m_llen = end - map->m_la;
if (flags & EROFS_GET_BLOCKS_FINDTAIL)
vi->z_tailextent_headlcn = m.lcn;
if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
map->m_flags |= EROFS_MAP_META;
map->m_pa = vi->z_idataoff;
map->m_plen = vi->z_idata_size;
} else {
map->m_pa = blknr_to_addr(m.pblk);
err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
if (err)
goto out;
}
if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN)
map->m_algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
else if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2)
map->m_algorithmformat = vi->z_algorithmtype[1];
else
map->m_algorithmformat = vi->z_algorithmtype[0];
if ((flags & EROFS_GET_BLOCKS_FIEMAP) ||
((flags & EROFS_GET_BLOCKS_READMORE) &&
map->m_algorithmformat == Z_EROFS_COMPRESSION_LZMA &&
map->m_llen >= EROFS_BLKSIZ)) {
err = z_erofs_get_extent_decompressedlen(&m);
if (!err)
map->m_flags |= EROFS_MAP_FULL_MAPPED;
}
unmap_out:
erofs_unmap_metabuf(&m.map->buf);
out:
erofs_dbg("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o",
__func__, map->m_la, map->m_pa,
map->m_llen, map->m_plen, map->m_flags);
return err;
}
int z_erofs_map_blocks_iter(struct inode *inode,
struct erofs_map_blocks *map,
int flags)
{
int err = 0;
trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
/* when trying to read beyond EOF, leave it unmapped */
if (map->m_la >= inode->i_size) {
map->m_llen = map->m_la + 1 - inode->i_size;
map->m_la = inode->i_size;
map->m_flags = 0;
goto out;
}
err = z_erofs_fill_inode_lazy(inode);
if (err)
goto out;
err = z_erofs_do_map_blocks(inode, map, flags);
out:
trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
/* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
DBG_BUGON(err < 0 && err != -ENOMEM);
return err;
}
static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
loff_t length, unsigned int flags,
struct iomap *iomap, struct iomap *srcmap)
{
int ret;
struct erofs_map_blocks map = { .m_la = offset };
ret = z_erofs_map_blocks_iter(inode, &map, EROFS_GET_BLOCKS_FIEMAP);
erofs_put_metabuf(&map.buf);
if (ret < 0)
return ret;
iomap->bdev = inode->i_sb->s_bdev;
iomap->offset = map.m_la;
iomap->length = map.m_llen;
if (map.m_flags & EROFS_MAP_MAPPED) {
iomap->type = IOMAP_MAPPED;
iomap->addr = map.m_pa;
} else {
iomap->type = IOMAP_HOLE;
iomap->addr = IOMAP_NULL_ADDR;
/*
* No strict rule how to describe extents for post EOF, yet
* we need do like below. Otherwise, iomap itself will get
* into an endless loop on post EOF.
*/
if (iomap->offset >= inode->i_size)
iomap->length = length + map.m_la - offset;
}
iomap->flags = 0;
return 0;
}
const struct iomap_ops z_erofs_iomap_report_ops = {
.iomap_begin = z_erofs_iomap_begin_report,
};
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