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1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2015 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <sys/sendfile.h> | |
23 | ||
24 | #include "sd-daemon.h" | |
25 | #include "util.h" | |
26 | #include "ratelimit.h" | |
27 | #include "btrfs-util.h" | |
28 | #include "import-common.h" | |
29 | #include "export-tar.h" | |
30 | #include "process-util.h" | |
31 | ||
32 | #define COPY_BUFFER_SIZE (16*1024) | |
33 | ||
34 | struct TarExport { | |
35 | sd_event *event; | |
36 | ||
37 | TarExportFinished on_finished; | |
38 | void *userdata; | |
39 | ||
40 | char *path; | |
41 | char *temp_path; | |
42 | ||
43 | int output_fd; | |
44 | int tar_fd; | |
45 | ||
46 | ImportCompress compress; | |
47 | ||
48 | sd_event_source *output_event_source; | |
49 | ||
50 | void *buffer; | |
51 | size_t buffer_size; | |
52 | size_t buffer_allocated; | |
53 | ||
54 | uint64_t written_compressed; | |
55 | uint64_t written_uncompressed; | |
56 | ||
57 | pid_t tar_pid; | |
58 | ||
59 | struct stat st; | |
60 | uint64_t quota_referenced; | |
61 | ||
62 | unsigned last_percent; | |
63 | RateLimit progress_rate_limit; | |
64 | ||
65 | bool eof; | |
66 | bool tried_splice; | |
67 | }; | |
68 | ||
69 | TarExport *tar_export_unref(TarExport *e) { | |
70 | if (!e) | |
71 | return NULL; | |
72 | ||
73 | sd_event_source_unref(e->output_event_source); | |
74 | ||
75 | if (e->tar_pid > 1) { | |
76 | (void) kill_and_sigcont(e->tar_pid, SIGKILL); | |
77 | (void) wait_for_terminate(e->tar_pid, NULL); | |
78 | } | |
79 | ||
80 | if (e->temp_path) { | |
81 | (void) btrfs_subvol_remove(e->temp_path, false); | |
82 | free(e->temp_path); | |
83 | } | |
84 | ||
85 | import_compress_free(&e->compress); | |
86 | ||
87 | sd_event_unref(e->event); | |
88 | ||
89 | safe_close(e->tar_fd); | |
90 | ||
91 | free(e->buffer); | |
92 | free(e->path); | |
93 | free(e); | |
94 | ||
95 | return NULL; | |
96 | } | |
97 | ||
98 | int tar_export_new( | |
99 | TarExport **ret, | |
100 | sd_event *event, | |
101 | TarExportFinished on_finished, | |
102 | void *userdata) { | |
103 | ||
104 | _cleanup_(tar_export_unrefp) TarExport *e = NULL; | |
105 | int r; | |
106 | ||
107 | assert(ret); | |
108 | ||
109 | e = new0(TarExport, 1); | |
110 | if (!e) | |
111 | return -ENOMEM; | |
112 | ||
113 | e->output_fd = e->tar_fd = -1; | |
114 | e->on_finished = on_finished; | |
115 | e->userdata = userdata; | |
116 | e->quota_referenced = (uint64_t) -1; | |
117 | ||
118 | RATELIMIT_INIT(e->progress_rate_limit, 100 * USEC_PER_MSEC, 1); | |
119 | e->last_percent = (unsigned) -1; | |
120 | ||
121 | if (event) | |
122 | e->event = sd_event_ref(event); | |
123 | else { | |
124 | r = sd_event_default(&e->event); | |
125 | if (r < 0) | |
126 | return r; | |
127 | } | |
128 | ||
129 | *ret = e; | |
130 | e = NULL; | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | static void tar_export_report_progress(TarExport *e) { | |
136 | unsigned percent; | |
137 | assert(e); | |
138 | ||
139 | /* Do we have any quota info? If not, we don't know anything about the progress */ | |
140 | if (e->quota_referenced == (uint64_t) -1) | |
141 | return; | |
142 | ||
143 | if (e->written_uncompressed >= e->quota_referenced) | |
144 | percent = 100; | |
145 | else | |
146 | percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / e->quota_referenced); | |
147 | ||
148 | if (percent == e->last_percent) | |
149 | return; | |
150 | ||
151 | if (!ratelimit_test(&e->progress_rate_limit)) | |
152 | return; | |
153 | ||
154 | sd_notifyf(false, "X_IMPORT_PROGRESS=%u", percent); | |
155 | log_info("Exported %u%%.", percent); | |
156 | ||
157 | e->last_percent = percent; | |
158 | } | |
159 | ||
160 | static int tar_export_process(TarExport *e) { | |
161 | ssize_t l; | |
162 | int r; | |
163 | ||
164 | assert(e); | |
165 | ||
166 | if (!e->tried_splice && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) { | |
167 | ||
168 | l = splice(e->tar_fd, NULL, e->output_fd, NULL, COPY_BUFFER_SIZE, 0); | |
169 | if (l < 0) { | |
170 | if (errno == EAGAIN) | |
171 | return 0; | |
172 | ||
173 | e->tried_splice = true; | |
174 | } else if (l == 0) { | |
175 | r = 0; | |
176 | goto finish; | |
177 | } else { | |
178 | e->written_uncompressed += l; | |
179 | e->written_compressed += l; | |
180 | ||
181 | tar_export_report_progress(e); | |
182 | ||
183 | return 0; | |
184 | } | |
185 | } | |
186 | ||
187 | while (e->buffer_size <= 0) { | |
188 | uint8_t input[COPY_BUFFER_SIZE]; | |
189 | ||
190 | if (e->eof) { | |
191 | r = 0; | |
192 | goto finish; | |
193 | } | |
194 | ||
195 | l = read(e->tar_fd, input, sizeof(input)); | |
196 | if (l < 0) { | |
197 | r = log_error_errno(errno, "Failed to read tar file: %m"); | |
198 | goto finish; | |
199 | } | |
200 | ||
201 | if (l == 0) { | |
202 | e->eof = true; | |
203 | r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated); | |
204 | } else { | |
205 | e->written_uncompressed += l; | |
206 | r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated); | |
207 | } | |
208 | if (r < 0) { | |
209 | r = log_error_errno(r, "Failed to encode: %m"); | |
210 | goto finish; | |
211 | } | |
212 | } | |
213 | ||
214 | l = write(e->output_fd, e->buffer, e->buffer_size); | |
215 | if (l < 0) { | |
216 | if (errno == EAGAIN) | |
217 | return 0; | |
218 | ||
219 | r = log_error_errno(errno, "Failed to write output file: %m"); | |
220 | goto finish; | |
221 | } | |
222 | ||
223 | assert((size_t) l <= e->buffer_size); | |
224 | memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l); | |
225 | e->buffer_size -= l; | |
226 | e->written_compressed += l; | |
227 | ||
228 | tar_export_report_progress(e); | |
229 | ||
230 | return 0; | |
231 | ||
232 | finish: | |
233 | if (e->on_finished) | |
234 | e->on_finished(e, r, e->userdata); | |
235 | else | |
236 | sd_event_exit(e->event, r); | |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
241 | static int tar_export_on_output(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
242 | TarExport *i = userdata; | |
243 | ||
244 | return tar_export_process(i); | |
245 | } | |
246 | ||
247 | static int tar_export_on_defer(sd_event_source *s, void *userdata) { | |
248 | TarExport *i = userdata; | |
249 | ||
250 | return tar_export_process(i); | |
251 | } | |
252 | ||
253 | int tar_export_start(TarExport *e, const char *path, int fd, ImportCompressType compress) { | |
254 | _cleanup_close_ int sfd = -1; | |
255 | int r; | |
256 | ||
257 | assert(e); | |
258 | assert(path); | |
259 | assert(fd >= 0); | |
260 | assert(compress < _IMPORT_COMPRESS_TYPE_MAX); | |
261 | assert(compress != IMPORT_COMPRESS_UNKNOWN); | |
262 | ||
263 | if (e->output_fd >= 0) | |
264 | return -EBUSY; | |
265 | ||
266 | sfd = open(path, O_DIRECTORY|O_RDONLY|O_NOCTTY|O_CLOEXEC); | |
267 | if (sfd < 0) | |
268 | return -errno; | |
269 | ||
270 | if (fstat(sfd, &e->st) < 0) | |
271 | return -errno; | |
272 | ||
273 | r = fd_nonblock(fd, true); | |
274 | if (r < 0) | |
275 | return r; | |
276 | ||
277 | r = free_and_strdup(&e->path, path); | |
278 | if (r < 0) | |
279 | return r; | |
280 | ||
281 | e->quota_referenced = (uint64_t) -1; | |
282 | ||
283 | if (e->st.st_ino == 256) { /* might be a btrfs subvolume? */ | |
284 | BtrfsQuotaInfo q; | |
285 | ||
286 | r = btrfs_subvol_get_quota_fd(sfd, &q); | |
287 | if (r >= 0) | |
288 | e->quota_referenced = q.referenced; | |
289 | ||
6300502b | 290 | e->temp_path = mfree(e->temp_path); |
e3bff60a | 291 | |
86f210e9 | 292 | r = tempfn_random(path, NULL, &e->temp_path); |
e3bff60a MP |
293 | if (r < 0) |
294 | return r; | |
295 | ||
296 | /* Let's try to make a snapshot, if we can, so that the export is atomic */ | |
297 | r = btrfs_subvol_snapshot_fd(sfd, e->temp_path, BTRFS_SNAPSHOT_READ_ONLY|BTRFS_SNAPSHOT_RECURSIVE); | |
298 | if (r < 0) { | |
299 | log_debug_errno(r, "Couldn't create snapshot %s of %s, not exporting atomically: %m", e->temp_path, path); | |
6300502b | 300 | e->temp_path = mfree(e->temp_path); |
e3bff60a MP |
301 | } |
302 | } | |
303 | ||
304 | r = import_compress_init(&e->compress, compress); | |
305 | if (r < 0) | |
306 | return r; | |
307 | ||
308 | r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, tar_export_on_output, e); | |
309 | if (r == -EPERM) { | |
310 | r = sd_event_add_defer(e->event, &e->output_event_source, tar_export_on_defer, e); | |
311 | if (r < 0) | |
312 | return r; | |
313 | ||
314 | r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON); | |
315 | } | |
316 | if (r < 0) | |
317 | return r; | |
318 | ||
319 | e->tar_fd = import_fork_tar_c(e->temp_path ?: e->path, &e->tar_pid); | |
320 | if (e->tar_fd < 0) { | |
321 | e->output_event_source = sd_event_source_unref(e->output_event_source); | |
322 | return e->tar_fd; | |
323 | } | |
324 | ||
325 | e->output_fd = fd; | |
326 | return r; | |
327 | } |