Merge "init: Add readahead built-in command" (12bd22ba) · Commits · e / os / android_system_core

init/README.md

+3 −0

Original line number	Diff line number	Diff line
		@@ -447,6 +447,9 @@ Commands
		`rmdir <path>`
		> Calls rmdir(2) on the given path.

		`readahead <file\|dir>`
		> Calls readahead(2) on the file or files within given directory.

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

init/builtins.cpp

+63 −1

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@
		#include <dirent.h>
		#include <errno.h>
		#include <fcntl.h>
		#include <fts.h>
		#include <linux/loop.h>
		#include <linux/module.h>
		#include <mntent.h>
		@@ -627,7 +628,7 @@ static int do_rmdir(const std::vector<std::string>& args) {

		static int do_sysclktz(const std::vector<std::string>& args) {
		struct timezone tz = {};
		if (android::base::ParseInt(args[1], &tz.tz_minuteswest) && settimeofday(NULL, &tz) != -1) {
		if (android::base::ParseInt(args[1], &tz.tz_minuteswest) && settimeofday(nullptr, &tz) != -1) {
		return 0;
		}
		return -1;
		@@ -660,6 +661,66 @@ static int do_write(const std::vector<std::string>& args) {
		return 0;
		}

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

		if (stat(args[1].c_str(), &sb)) {
		PLOG(ERROR) << "Error opening " << args[1];
		return -1;
		}

		// 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
		// occurs frequently with ext[234] on large files using indirect blocks
		// instead of extents, giving the appearance that the call blocks until
		// the requested data has been read.
		pid_t pid = fork();
		if (pid == 0) {
		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];
		_exit(EXIT_FAILURE);
		}
		} else if (S_ISDIR(sb.st_mode)) {
		char* paths[] = {const_cast<char*>(args[1].data()), nullptr};
		std::unique_ptr<FTS, decltype(&fts_close)> fts(
		fts_open(paths, FTS_PHYSICAL \| FTS_NOCHDIR \| FTS_XDEV, nullptr), fts_close);
		if (!fts) {
		PLOG(ERROR) << "Error opening directory: " << args[1];
		_exit(EXIT_FAILURE);
		}
		// Traverse the entire hierarchy and do readahead
		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;
		}
		}
		}
		}
		LOG(INFO) << "Readahead " << args[1] << " took " << t;
		_exit(0);
		} else if (pid < 0) {
		PLOG(ERROR) << "Fork failed";
		return -1;
		}
		return 0;
		}

		static int do_copy(const std::vector<std::string>& args) {
		std::string data;
		std::string err;
		@@ -898,6 +959,7 @@ 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}},
		{"restart", {1, 1, do_restart}},
		{"restorecon", {1, kMax, do_restorecon}},
		{"restorecon_recursive", {1, kMax, do_restorecon_recursive}},