blob: f4b21d7917a34d51b720c7ea82c0b7f557d6301f [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
#include "internal.h"
#include "decompress.h"
static int erofs_map_blocks_flatmode(struct erofs_inode *inode,
struct erofs_map_blocks *map,
int flags)
{
int err = 0;
erofs_blk_t nblocks, lastblk;
u64 offset = map->m_la;
struct erofs_inode *vi = inode;
bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);
nblocks = BLK_ROUND_UP(inode->i_size);
lastblk = nblocks - tailendpacking;
/* there is no hole in flatmode */
map->m_flags = EROFS_MAP_MAPPED;
if (offset < erofs_pos(lastblk)) {
map->m_pa = erofs_pos(vi->u.i_blkaddr) + map->m_la;
map->m_plen = erofs_pos(lastblk) - offset;
} else if (tailendpacking) {
/* 2 - inode inline B: inode, [xattrs], inline last blk... */
map->m_pa = iloc(vi->nid) + vi->inode_isize +
vi->xattr_isize + erofs_blkoff(map->m_la);
map->m_plen = inode->i_size - offset;
/* inline data should be located in the same meta block */
if (erofs_blkoff(map->m_pa) + map->m_plen > erofs_blksiz()) {
erofs_err("inline data cross block boundary @ nid %" PRIu64,
vi->nid);
DBG_BUGON(1);
err = -EFSCORRUPTED;
goto err_out;
}
map->m_flags |= EROFS_MAP_META;
} else {
erofs_err("internal error @ nid: %" PRIu64 " (size %llu), m_la 0x%" PRIx64,
vi->nid, (unsigned long long)inode->i_size, map->m_la);
DBG_BUGON(1);
err = -EIO;
goto err_out;
}
map->m_llen = map->m_plen;
err_out:
return err;
}
int erofs_map_blocks(struct erofs_inode *inode,
struct erofs_map_blocks *map, int flags)
{
struct erofs_inode *vi = inode;
struct erofs_inode_chunk_index *idx;
u8 buf[EROFS_MAX_BLOCK_SIZE];
u64 chunknr;
unsigned int unit;
erofs_off_t pos;
int err = 0;
map->m_deviceid = 0;
if (map->m_la >= inode->i_size) {
/* leave out-of-bound access unmapped */
map->m_flags = 0;
map->m_plen = 0;
goto out;
}
if (vi->datalayout != EROFS_INODE_CHUNK_BASED)
return erofs_map_blocks_flatmode(inode, map, flags);
if (vi->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
unit = sizeof(*idx); /* chunk index */
else
unit = EROFS_BLOCK_MAP_ENTRY_SIZE; /* block map */
chunknr = map->m_la >> vi->u.chunkbits;
pos = roundup(iloc(vi->nid) + vi->inode_isize +
vi->xattr_isize, unit) + unit * chunknr;
err = erofs_blk_read(buf, erofs_blknr(pos), 1);
if (err < 0)
return -EIO;
map->m_la = chunknr << vi->u.chunkbits;
map->m_plen = min_t(erofs_off_t, 1UL << vi->u.chunkbits,
roundup(inode->i_size - map->m_la, erofs_blksiz()));
/* handle block map */
if (!(vi->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
__le32 *blkaddr = (void *)buf + erofs_blkoff(pos);
if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
map->m_flags = 0;
} else {
map->m_pa = erofs_pos(le32_to_cpu(*blkaddr));
map->m_flags = EROFS_MAP_MAPPED;
}
goto out;
}
/* parse chunk indexes */
idx = (void *)buf + erofs_blkoff(pos);
switch (le32_to_cpu(idx->blkaddr)) {
case EROFS_NULL_ADDR:
map->m_flags = 0;
break;
default:
map->m_deviceid = le16_to_cpu(idx->device_id) &
sbi.device_id_mask;
map->m_pa = erofs_pos(le32_to_cpu(idx->blkaddr));
map->m_flags = EROFS_MAP_MAPPED;
break;
}
out:
map->m_llen = map->m_plen;
return err;
}
int erofs_map_dev(struct erofs_map_dev *map)
{
struct erofs_device_info *dif;
int id;
if (map->m_deviceid) {
if (sbi.extra_devices < map->m_deviceid)
return -ENODEV;
} else if (sbi.extra_devices) {
for (id = 0; id < sbi.extra_devices; ++id) {
erofs_off_t startoff, length;
dif = sbi.devs + id;
if (!dif->mapped_blkaddr)
continue;
startoff = erofs_pos(dif->mapped_blkaddr);
length = erofs_pos(dif->blocks);
if (map->m_pa >= startoff &&
map->m_pa < startoff + length) {
map->m_pa -= startoff;
break;
}
}
}
return 0;
}
int erofs_read_one_data(struct erofs_map_blocks *map, char *buffer, u64 offset,
size_t len)
{
struct erofs_map_dev mdev;
int ret;
mdev = (struct erofs_map_dev) {
.m_deviceid = map->m_deviceid,
.m_pa = map->m_pa,
};
ret = erofs_map_dev(&mdev);
if (ret)
return ret;
ret = erofs_dev_read(mdev.m_deviceid, buffer, mdev.m_pa + offset, len);
if (ret < 0)
return -EIO;
return 0;
}
static int erofs_read_raw_data(struct erofs_inode *inode, char *buffer,
erofs_off_t size, erofs_off_t offset)
{
struct erofs_map_blocks map = {
.index = UINT_MAX,
};
int ret;
erofs_off_t ptr = offset;
while (ptr < offset + size) {
char *const estart = buffer + ptr - offset;
erofs_off_t eend, moff = 0;
map.m_la = ptr;
ret = erofs_map_blocks(inode, &map, 0);
if (ret)
return ret;
DBG_BUGON(map.m_plen != map.m_llen);
/* trim extent */
eend = min(offset + size, map.m_la + map.m_llen);
DBG_BUGON(ptr < map.m_la);
if (!(map.m_flags & EROFS_MAP_MAPPED)) {
if (!map.m_llen) {
/* reached EOF */
memset(estart, 0, offset + size - ptr);
ptr = offset + size;
continue;
}
memset(estart, 0, eend - ptr);
ptr = eend;
continue;
}
if (ptr > map.m_la) {
moff = ptr - map.m_la;
map.m_la = ptr;
}
ret = erofs_read_one_data(&map, estart, moff, eend - map.m_la);
if (ret)
return ret;
ptr = eend;
}
return 0;
}
int z_erofs_read_one_data(struct erofs_inode *inode,
struct erofs_map_blocks *map, char *raw, char *buffer,
erofs_off_t skip, erofs_off_t length, bool trimmed)
{
struct erofs_map_dev mdev;
int ret = 0;
if (map->m_flags & EROFS_MAP_FRAGMENT) {
struct erofs_inode packed_inode = {
.nid = sbi.packed_nid,
};
ret = erofs_read_inode_from_disk(&packed_inode);
if (ret) {
erofs_err("failed to read packed inode from disk");
return ret;
}
return erofs_pread(&packed_inode, buffer, length - skip,
inode->fragmentoff + skip);
}
/* no device id here, thus it will always succeed */
mdev = (struct erofs_map_dev) {
.m_pa = map->m_pa,
};
ret = erofs_map_dev(&mdev);
if (ret) {
DBG_BUGON(1);
return ret;
}
ret = erofs_dev_read(mdev.m_deviceid, raw, mdev.m_pa, map->m_plen);
if (ret < 0)
return ret;
ret = z_erofs_decompress(&(struct z_erofs_decompress_req) {
.in = raw,
.out = buffer,
.decodedskip = skip,
.interlaced_offset =
map->m_algorithmformat == Z_EROFS_COMPRESSION_INTERLACED ?
erofs_blkoff(map->m_la) : 0,
.inputsize = map->m_plen,
.decodedlength = length,
.alg = map->m_algorithmformat,
.partial_decoding = trimmed ? true :
!(map->m_flags & EROFS_MAP_FULL_MAPPED) ||
(map->m_flags & EROFS_MAP_PARTIAL_REF),
});
if (ret < 0)
return ret;
return 0;
}
static int z_erofs_read_data(struct erofs_inode *inode, char *buffer,
erofs_off_t size, erofs_off_t offset)
{
erofs_off_t end, length, skip;
struct erofs_map_blocks map = {
.index = UINT_MAX,
};
bool trimmed;
unsigned int bufsize = 0;
char *raw = NULL;
int ret = 0;
end = offset + size;
while (end > offset) {
map.m_la = end - 1;
ret = z_erofs_map_blocks_iter(inode, &map, 0);
if (ret)
break;
/*
* trim to the needed size if the returned extent is quite
* larger than requested, and set up partial flag as well.
*/
if (end < map.m_la + map.m_llen) {
length = end - map.m_la;
trimmed = true;
} else {
DBG_BUGON(end != map.m_la + map.m_llen);
length = map.m_llen;
trimmed = false;
}
if (map.m_la < offset) {
skip = offset - map.m_la;
end = offset;
} else {
skip = 0;
end = map.m_la;
}
if (!(map.m_flags & EROFS_MAP_MAPPED)) {
memset(buffer + end - offset, 0, length);
end = map.m_la;
continue;
}
if (map.m_plen > bufsize) {
bufsize = map.m_plen;
raw = realloc(raw, bufsize);
if (!raw) {
ret = -ENOMEM;
break;
}
}
ret = z_erofs_read_one_data(inode, &map, raw,
buffer + end - offset, skip, length,
trimmed);
if (ret < 0)
break;
}
if (raw)
free(raw);
return ret < 0 ? ret : 0;
}
int erofs_pread(struct erofs_inode *inode, char *buf,
erofs_off_t count, erofs_off_t offset)
{
switch (inode->datalayout) {
case EROFS_INODE_FLAT_PLAIN:
case EROFS_INODE_FLAT_INLINE:
case EROFS_INODE_CHUNK_BASED:
return erofs_read_raw_data(inode, buf, count, offset);
case EROFS_INODE_COMPRESSED_FULL:
case EROFS_INODE_COMPRESSED_COMPACT:
return z_erofs_read_data(inode, buf, count, offset);
default:
break;
}
return -EINVAL;
}