Merge "init: add option to read file fully on readahead" (d97a1710) · Commits · e / os / android_system_core

init/README.md

+2 −1

Original line number	Diff line number	Diff line
		@@ -453,8 +453,9 @@ Commands
		`rmdir <path>`
		> Calls rmdir(2) on the given path.

		`readahead <file\|dir>`
		`readahead <file\|dir> [--fully]`
		> Calls readahead(2) on the file or files within given directory.
		Use option --fully to read the full file content.

		`setprop <name> <value>`
		> Set system property _name_ to _value_. Properties are expanded

init/builtins.cpp

+42 −17

Original line number	Diff line number	Diff line
		@@ -56,6 +56,7 @@
		#include <selinux/android.h>
		#include <selinux/label.h>
		#include <selinux/selinux.h>
		#include <system/thread_defs.h>

		#include "action.h"
		#include "bootchart.h"
		@@ -670,6 +671,29 @@ static Result<Success> do_write(const std::vector<std::string>& args) {
		return Success();
		}

		static Result<Success> readahead_file(const std::string& filename, bool fully) {
		android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(filename.c_str(), O_RDONLY)));
		if (fd == -1) {
		return ErrnoError() << "Error opening file";
		}
		if (posix_fadvise(fd, 0, 0, POSIX_FADV_WILLNEED)) {
		return ErrnoError() << "Error posix_fadvise file";
		}
		if (readahead(fd, 0, std::numeric_limits<size_t>::max())) {
		return ErrnoError() << "Error readahead file";
		}
		if (fully) {
		char buf[BUFSIZ];
		ssize_t n;
		while ((n = TEMP_FAILURE_RETRY(read(fd, &buf[0], sizeof(buf)))) > 0) {
		}
		if (n != 0) {
		return ErrnoError() << "Error reading file";
		}
		}
		return Success();
		}

		static Result<Success> do_readahead(const std::vector<std::string>& args) {
		struct stat sb;

		@@ -677,6 +701,10 @@ static Result<Success> do_readahead(const std::vector<std::string>& args) {
		return ErrnoError() << "Error opening " << args[1];
		}

		bool readfully = false;
		if (args.size() == 3 && args[2] == "--fully") {
		readfully = true;
		}
		// We will do readahead in a forked process in order not to block init
		// since it may block while it reads the
		// filesystem metadata needed to locate the requested blocks. This
		@@ -685,15 +713,16 @@ static Result<Success> do_readahead(const std::vector<std::string>& args) {
		// the requested data has been read.
		pid_t pid = fork();
		if (pid == 0) {
		if (setpriority(PRIO_PROCESS, 0, static_cast<int>(ANDROID_PRIORITY_LOWEST)) != 0) {
		PLOG(WARNING) << "setpriority failed";
		}
		if (android_set_ioprio(0, IoSchedClass_IDLE, 7)) {
		PLOG(WARNING) << "ioprio_get failed";
		}
		android::base::Timer t;
		if (S_ISREG(sb.st_mode)) {
		android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(args[1].c_str(), O_RDONLY)));
		if (fd == -1) {
		PLOG(ERROR) << "Error opening file: " << args[1];
		_exit(EXIT_FAILURE);
		}
		if (readahead(fd, 0, std::numeric_limits<size_t>::max())) {
		PLOG(ERROR) << "Error readahead file: " << args[1];
		if (auto result = readahead_file(args[1], readfully); !result) {
		LOG(WARNING) << "Unable to readahead '" << args[1] << "': " << result.error();
		_exit(EXIT_FAILURE);
		}
		} else if (S_ISDIR(sb.st_mode)) {
		@@ -708,19 +737,15 @@ static Result<Success> do_readahead(const std::vector<std::string>& args) {
		for (FTSENT* ftsent = fts_read(fts.get()); ftsent != nullptr;
		ftsent = fts_read(fts.get())) {
		if (ftsent->fts_info & FTS_F) {
		android::base::unique_fd fd(
		TEMP_FAILURE_RETRY(open(ftsent->fts_accpath, O_RDONLY)));
		if (fd == -1) {
		PLOG(ERROR) << "Error opening file: " << args[1];
		continue;
		}
		if (readahead(fd, 0, std::numeric_limits<size_t>::max())) {
		PLOG(ERROR) << "Unable to readahead on file: " << ftsent->fts_accpath;
		const std::string filename = ftsent->fts_accpath;
		if (auto result = readahead_file(filename, readfully); !result) {
		LOG(WARNING)
		<< "Unable to readahead '" << filename << "': " << result.error();
		}
		}
		}
		}
		LOG(INFO) << "Readahead " << args[1] << " took " << t;
		LOG(INFO) << "Readahead " << args[1] << " took " << t << " asynchronously";
		_exit(0);
		} else if (pid < 0) {
		return ErrnoError() << "Fork failed";
		@@ -949,7 +974,7 @@ const BuiltinFunctionMap::Map& BuiltinFunctionMap::map() const {
		{"mount_all", {1, kMax, do_mount_all}},
		{"mount", {3, kMax, do_mount}},
		{"umount", {1, 1, do_umount}},
		{"readahead", {1, 1, do_readahead}},
		{"readahead", {1, 2, do_readahead}},
		{"restart", {1, 1, do_restart}},
		{"restorecon", {1, kMax, do_restorecon}},
		{"restorecon_recursive", {1, kMax, do_restorecon_recursive}},