tequilaOS/platform_bootable_recovery
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Skip stashing source blocks in verify mode

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Currently block_image_verify() stashes source blocks to /cache and
in some case triggers I/O errors. To avoid this risk, We create
a map from the hash value to the source blocks' range_set. When
executing stash command in verify mode, source range is saved but block
contents aren't stashed. And load_stash could get its value from
either the stashed file from the previous update, or the contents on
the source partition specified by the saved range.

Bug: 27584487
Bug: 25633753
Change-Id: I775baf4bee55762b6e7b204f8294afc597afd996
This commit is contained in:
Tianjie Xu 2016-03-22 18:08:12 -07:00
parent f73abf36bc
commit 0188935d55
1 changed files with 46 additions and 8 deletions
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54
updater/blockimg.cpp
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@ -33,6 +33,7 @@
#include <unistd.h>
#include <fec/io.h>
#include <map>
#include <memory>
#include <string>
#include <vector>
@ -67,6 +68,8 @@ struct RangeSet {
std::vector<size_t> pos; // Actual limit is INT_MAX.
};
static std::map<std::string, RangeSet> stash_map;
static void parse_range(const std::string& range_text, RangeSet& rs) {
std::vector<std::string> pieces = android::base::Split(range_text, ",");
@ -522,8 +525,28 @@ static void DeleteStash(const std::string& base) {
}
}
static int LoadStash(const std::string& base, const std::string& id, bool verify, size_t* blocks,
std::vector<uint8_t>& buffer, bool printnoent) {
static int LoadStash(CommandParameters& params, const std::string& base, const std::string& id,
bool verify, size_t* blocks, std::vector<uint8_t>& buffer, bool printnoent) {
// In verify mode, if source range_set was saved for the given hash,
// check contents in the source blocks first. If the check fails,
// search for the stashed files on /cache as usual.
if (!params.canwrite) {
if (stash_map.find(id) != stash_map.end()) {
const RangeSet& src = stash_map[id];
allocate(src.size * BLOCKSIZE, buffer);
if (ReadBlocks(src, buffer, params.fd) == -1) {
fprintf(stderr, "failed to read source blocks in stash map.\n");
return -1;
}
if (VerifyBlocks(id, buffer, src.size, true) != 0) {
fprintf(stderr, "failed to verify loaded source blocks in stash map.\n");
return -1;
}
return 0;
}
}
if (base.empty()) {
return -1;
}
@ -722,7 +745,7 @@ static int SaveStash(CommandParameters& params, const std::string& base,
const std::string& id = params.tokens[params.cpos++];
size_t blocks = 0;
if (usehash && LoadStash(base, id, true, &blocks, buffer, false) == 0) {
if (usehash && LoadStash(params, base, id, true, &blocks, buffer, false) == 0) {
// Stash file already exists and has expected contents. Do not
// read from source again, as the source may have been already
// overwritten during a previous attempt.
@ -747,6 +770,12 @@ static int SaveStash(CommandParameters& params, const std::string& base,
return 0;
}
// In verify mode, save source range_set instead of stashing blocks.
if (!params.canwrite && usehash) {
stash_map[id] = src;
return 0;
}
fprintf(stderr, "stashing %zu blocks to %s\n", blocks, id.c_str());
return WriteStash(base, id, blocks, buffer, false, nullptr);
}
@ -857,7 +886,7 @@ static int LoadSrcTgtVersion2(CommandParameters& params, RangeSet& tgt, size_t&
}
std::vector<uint8_t> stash;
int res = LoadStash(stashbase, tokens[0], false, nullptr, stash, true);
int res = LoadStash(params, stashbase, tokens[0], false, nullptr, stash, true);
if (res == -1) {
// These source blocks will fail verification if used later, but we
@ -931,8 +960,9 @@ static int LoadSrcTgtVersion3(CommandParameters& params, RangeSet& tgt, size_t&
if (VerifyBlocks(srchash, params.buffer, src_blocks, true) == 0) {
// If source and target blocks overlap, stash the source blocks so we can
// resume from possible write errors
if (overlap) {
// resume from possible write errors. In verify mode, we can skip stashing
// because the source blocks won't be overwritten.
if (overlap && params.canwrite) {
fprintf(stderr, "stashing %zu overlapping blocks to %s\n", src_blocks,
srchash.c_str());
@ -953,7 +983,8 @@ static int LoadSrcTgtVersion3(CommandParameters& params, RangeSet& tgt, size_t&
return 0;
}
if (overlap && LoadStash(params.stashbase, srchash, true, nullptr, params.buffer, true) == 0) {
if (overlap && LoadStash(params, params.stashbase, srchash, true, nullptr, params.buffer,
true) == 0) {
// Overlapping source blocks were previously stashed, command can proceed.
// We are recovering from an interrupted command, so we don't know if the
// stash can safely be deleted after this command.
@ -1028,8 +1059,15 @@ static int PerformCommandFree(CommandParameters& params) {
return -1;
}
const std::string& id = params.tokens[params.cpos++];
if (!params.canwrite && stash_map.find(id) != stash_map.end()) {
stash_map.erase(id);
return 0;
}
if (params.createdstash || params.canwrite) {
return FreeStash(params.stashbase, params.tokens[params.cpos++]);
return FreeStash(params.stashbase, id);
}
return 0;