1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include <algorithm>
#include <limits>
#include <memory>
#include <set>
#include <string>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include "applypatch/applypatch.h"
#include "otautil/paths.h"
static int EliminateOpenFiles(const std::string& dirname, std::set<std::string>* files) {
std::unique_ptr<DIR, decltype(&closedir)> d(opendir("/proc"), closedir);
if (!d) {
PLOG(ERROR) << "Failed to open /proc";
return -1;
}
struct dirent* de;
while ((de = readdir(d.get())) != 0) {
unsigned int pid;
if (!android::base::ParseUint(de->d_name, &pid)) {
continue;
}
std::string path = android::base::StringPrintf("/proc/%s/fd/", de->d_name);
struct dirent* fdde;
std::unique_ptr<DIR, decltype(&closedir)> fdd(opendir(path.c_str()), closedir);
if (!fdd) {
PLOG(ERROR) << "Failed to open " << path;
continue;
}
while ((fdde = readdir(fdd.get())) != 0) {
std::string fd_path = path + fdde->d_name;
char link[FILENAME_MAX];
int count = readlink(fd_path.c_str(), link, sizeof(link)-1);
if (count >= 0) {
link[count] = '\0';
if (android::base::StartsWith(link, dirname)) {
if (files->erase(link) > 0) {
LOG(INFO) << link << " is open by " << de->d_name;
}
}
}
}
}
return 0;
}
static std::vector<std::string> FindExpendableFiles(
const std::string& dirname, const std::function<bool(const std::string&)>& name_filter) {
std::unique_ptr<DIR, decltype(&closedir)> d(opendir(dirname.c_str()), closedir);
if (!d) {
PLOG(ERROR) << "Failed to open " << dirname;
return {};
}
// Look for regular files in the directory (not in any subdirectories).
std::set<std::string> files;
struct dirent* de;
while ((de = readdir(d.get())) != 0) {
std::string path = dirname + "/" + de->d_name;
// We can't delete cache_temp_source; if it's there we might have restarted during
// installation and could be depending on it to be there.
if (path == Paths::Get().cache_temp_source()) {
continue;
}
// Do not delete the file if it doesn't have the expected format.
if (name_filter != nullptr && !name_filter(de->d_name)) {
continue;
}
struct stat st;
if (stat(path.c_str(), &st) == 0 && S_ISREG(st.st_mode)) {
files.insert(path);
}
}
LOG(INFO) << files.size() << " regular files in deletable directory";
if (EliminateOpenFiles(dirname, &files) < 0) {
return {};
}
return std::vector<std::string>(files.begin(), files.end());
}
// Parses the index of given log file, e.g. 3 for last_log.3; returns max number if the log name
// doesn't have the expected format so that we'll delete these ones first.
static unsigned int GetLogIndex(const std::string& log_name) {
if (log_name == "last_log" || log_name == "last_kmsg") {
return 0;
}
unsigned int index;
if (sscanf(log_name.c_str(), "last_log.%u", &index) == 1 ||
sscanf(log_name.c_str(), "last_kmsg.%u", &index) == 1) {
return index;
}
return std::numeric_limits<unsigned int>::max();
}
int MakeFreeSpaceOnCache(size_t bytes_needed) {
#ifndef __ANDROID__
// TODO(xunchang): Implement a heuristic cache size check during host simulation.
LOG(WARNING) << "Skipped making (" << bytes_needed
<< ") bytes free space on /cache; program is running on host";
return 0;
#endif
std::vector<std::string> dirs{ "/cache", Paths::Get().cache_log_directory() };
for (const auto& dirname : dirs) {
if (RemoveFilesInDirectory(bytes_needed, dirname, FreeSpaceForFile)) {
return 0;
}
}
return -1;
}
bool RemoveFilesInDirectory(size_t bytes_needed, const std::string& dirname,
const std::function<size_t(const std::string&)>& space_checker) {
struct stat st;
if (stat(dirname.c_str(), &st) == -1) {
PLOG(ERROR) << "Failed to stat " << dirname;
return false;
}
if (!S_ISDIR(st.st_mode)) {
LOG(ERROR) << dirname << " is not a directory";
return false;
}
size_t free_now = space_checker(dirname);
LOG(INFO) << free_now << " bytes free on " << dirname << " (" << bytes_needed << " needed)";
if (free_now >= bytes_needed) {
return true;
}
std::vector<std::string> files;
if (dirname == Paths::Get().cache_log_directory()) {
// Deletes the log files only.
auto log_filter = [](const std::string& file_name) {
return android::base::StartsWith(file_name, "last_log") ||
android::base::StartsWith(file_name, "last_kmsg");
};
files = FindExpendableFiles(dirname, log_filter);
// Older logs will come to the top of the queue.
auto comparator = [](const std::string& name1, const std::string& name2) -> bool {
unsigned int index1 = GetLogIndex(android::base::Basename(name1));
unsigned int index2 = GetLogIndex(android::base::Basename(name2));
if (index1 == index2) {
return name1 < name2;
}
return index1 > index2;
};
std::sort(files.begin(), files.end(), comparator);
} else {
// We're allowed to delete unopened regular files in the directory.
files = FindExpendableFiles(dirname, nullptr);
}
for (const auto& file : files) {
if (unlink(file.c_str()) == -1) {
PLOG(ERROR) << "Failed to delete " << file;
continue;
}
free_now = space_checker(dirname);
LOG(INFO) << "Deleted " << file << "; now " << free_now << " bytes free";
if (free_now >= bytes_needed) {
return true;
}
}
return false;
}
|
