From bc42603a8daae62b158d159c97ef8acfaa39d70d Mon Sep 17 00:00:00 2001 From: Tianjie Xu Date: Fri, 11 Nov 2016 13:53:25 -0800 Subject: Retry ioctl in uncrypt if it returns block# 0 In some conditions, ioctl(fd, FIBMAP, &block) returns block number 0.This is a failure to locate the actual block number of the update package and will result in an invalid block.map. This CL retries ioctl a few times if it returns block number as 0. Bug: 31632090 Test: On N9, uncrypt retries ioctl and produces the correct blockmap. Change-Id: I913f98cf5c112915c2e803d0683db273c89053b6 --- uncrypt/uncrypt.cpp | 41 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) (limited to 'uncrypt/uncrypt.cpp') diff --git a/uncrypt/uncrypt.cpp b/uncrypt/uncrypt.cpp index e1b6a1c20..b23f6be92 100644 --- a/uncrypt/uncrypt.cpp +++ b/uncrypt/uncrypt.cpp @@ -118,7 +118,8 @@ #include "error_code.h" -#define WINDOW_SIZE 5 +static constexpr int WINDOW_SIZE = 5; +static constexpr int FIBMAP_RETRY_LIMIT = 3; // uncrypt provides three services: SETUP_BCB, CLEAR_BCB and UNCRYPT. // @@ -233,6 +234,26 @@ static bool find_uncrypt_package(const std::string& uncrypt_path_file, std::stri return true; } +static int retry_fibmap(const int fd, const char* name, int* block, const int head_block) { + CHECK(block != nullptr); + for (size_t i = 0; i < FIBMAP_RETRY_LIMIT; i++) { + if (fsync(fd) == -1) { + PLOG(ERROR) << "failed to fsync \"" << name << "\""; + return kUncryptFileSyncError; + } + if (ioctl(fd, FIBMAP, block) != 0) { + PLOG(ERROR) << "failed to find block " << head_block; + return kUncryptIoctlError; + } + if (*block != 0) { + return kUncryptNoError; + } + sleep(1); + } + LOG(ERROR) << "fibmap of " << head_block << "always returns 0"; + return kUncryptIoctlError; +} + static int produce_block_map(const char* path, const char* map_file, const char* blk_dev, bool encrypted, int socket) { std::string err; @@ -314,6 +335,15 @@ static int produce_block_map(const char* path, const char* map_file, const char* PLOG(ERROR) << "failed to find block " << head_block; return kUncryptIoctlError; } + + if (block == 0) { + LOG(ERROR) << "failed to find block " << head_block << ", retrying"; + int error = retry_fibmap(fd, path, &block, head_block); + if (error != kUncryptNoError) { + return error; + } + } + add_block_to_ranges(ranges, block); if (encrypted) { if (write_at_offset(buffers[head].data(), sb.st_blksize, wfd, @@ -350,6 +380,15 @@ static int produce_block_map(const char* path, const char* map_file, const char* PLOG(ERROR) << "failed to find block " << head_block; return kUncryptIoctlError; } + + if (block == 0) { + LOG(ERROR) << "failed to find block " << head_block << ", retrying"; + int error = retry_fibmap(fd, path, &block, head_block); + if (error != kUncryptNoError) { + return error; + } + } + add_block_to_ranges(ranges, block); if (encrypted) { if (write_at_offset(buffers[head].data(), sb.st_blksize, wfd, -- cgit v1.2.3