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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 | ||
31 | #define COPY_BUFFER_SIZE (16*1024) | |
32 | ||
33 | struct TarExport { | |
34 | sd_event *event; | |
35 | ||
36 | TarExportFinished on_finished; | |
37 | void *userdata; | |
38 | ||
39 | char *path; | |
40 | char *temp_path; | |
41 | ||
42 | int output_fd; | |
43 | int tar_fd; | |
44 | ||
45 | ImportCompress compress; | |
46 | ||
47 | sd_event_source *output_event_source; | |
48 | ||
49 | void *buffer; | |
50 | size_t buffer_size; | |
51 | size_t buffer_allocated; | |
52 | ||
53 | uint64_t written_compressed; | |
54 | uint64_t written_uncompressed; | |
55 | ||
56 | pid_t tar_pid; | |
57 | ||
58 | struct stat st; | |
59 | uint64_t quota_referenced; | |
60 | ||
61 | unsigned last_percent; | |
62 | RateLimit progress_rate_limit; | |
63 | ||
64 | bool eof; | |
65 | bool tried_splice; | |
66 | }; | |
67 | ||
68 | TarExport *tar_export_unref(TarExport *e) { | |
69 | if (!e) | |
70 | return NULL; | |
71 | ||
72 | sd_event_source_unref(e->output_event_source); | |
73 | ||
74 | if (e->tar_pid > 1) { | |
75 | (void) kill_and_sigcont(e->tar_pid, SIGKILL); | |
76 | (void) wait_for_terminate(e->tar_pid, NULL); | |
77 | } | |
78 | ||
79 | if (e->temp_path) { | |
d9e2daaf | 80 | (void) btrfs_subvol_remove(e->temp_path, false); |
587fec42 LP |
81 | free(e->temp_path); |
82 | } | |
83 | ||
84 | import_compress_free(&e->compress); | |
85 | ||
86 | sd_event_unref(e->event); | |
87 | ||
88 | safe_close(e->tar_fd); | |
89 | ||
90 | free(e->buffer); | |
91 | free(e->path); | |
92 | free(e); | |
93 | ||
94 | return NULL; | |
95 | } | |
96 | ||
97 | int tar_export_new( | |
98 | TarExport **ret, | |
99 | sd_event *event, | |
100 | TarExportFinished on_finished, | |
101 | void *userdata) { | |
102 | ||
103 | _cleanup_(tar_export_unrefp) TarExport *e = NULL; | |
104 | int r; | |
105 | ||
106 | assert(ret); | |
107 | ||
108 | e = new0(TarExport, 1); | |
109 | if (!e) | |
110 | return -ENOMEM; | |
111 | ||
112 | e->output_fd = e->tar_fd = -1; | |
113 | e->on_finished = on_finished; | |
114 | e->userdata = userdata; | |
115 | e->quota_referenced = (uint64_t) -1; | |
116 | ||
117 | RATELIMIT_INIT(e->progress_rate_limit, 100 * USEC_PER_MSEC, 1); | |
118 | e->last_percent = (unsigned) -1; | |
119 | ||
120 | if (event) | |
121 | e->event = sd_event_ref(event); | |
122 | else { | |
123 | r = sd_event_default(&e->event); | |
124 | if (r < 0) | |
125 | return r; | |
126 | } | |
127 | ||
128 | *ret = e; | |
129 | e = NULL; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static void tar_export_report_progress(TarExport *e) { | |
135 | unsigned percent; | |
136 | assert(e); | |
137 | ||
138 | /* Do we have any quota info? I fnot, we don't know anything about the progress */ | |
139 | if (e->quota_referenced == (uint64_t) -1) | |
140 | return; | |
141 | ||
142 | if (e->written_uncompressed >= e->quota_referenced) | |
143 | percent = 100; | |
144 | else | |
145 | percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / e->quota_referenced); | |
146 | ||
147 | if (percent == e->last_percent) | |
148 | return; | |
149 | ||
150 | if (!ratelimit_test(&e->progress_rate_limit)) | |
151 | return; | |
152 | ||
153 | sd_notifyf(false, "X_IMPORT_PROGRESS=%u", percent); | |
154 | log_info("Exported %u%%.", percent); | |
155 | ||
156 | e->last_percent = percent; | |
157 | } | |
158 | ||
159 | static int tar_export_process(TarExport *e) { | |
160 | ssize_t l; | |
161 | int r; | |
162 | ||
163 | assert(e); | |
164 | ||
165 | if (!e->tried_splice && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) { | |
166 | ||
167 | l = splice(e->tar_fd, NULL, e->output_fd, NULL, COPY_BUFFER_SIZE, 0); | |
168 | if (l < 0) { | |
169 | if (errno == EAGAIN) | |
170 | return 0; | |
171 | ||
172 | e->tried_splice = true; | |
173 | } else if (l == 0) { | |
174 | r = 0; | |
175 | goto finish; | |
176 | } else { | |
177 | e->written_uncompressed += l; | |
178 | e->written_compressed += l; | |
179 | ||
180 | tar_export_report_progress(e); | |
181 | ||
182 | return 0; | |
183 | } | |
184 | } | |
185 | ||
186 | while (e->buffer_size <= 0) { | |
187 | uint8_t input[COPY_BUFFER_SIZE]; | |
188 | ||
189 | if (e->eof) { | |
190 | r = 0; | |
191 | goto finish; | |
192 | } | |
193 | ||
194 | l = read(e->tar_fd, input, sizeof(input)); | |
195 | if (l < 0) { | |
196 | r = log_error_errno(errno, "Failed to read tar file: %m"); | |
197 | goto finish; | |
198 | } | |
199 | ||
200 | if (l == 0) { | |
201 | e->eof = true; | |
202 | r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated); | |
203 | } else { | |
204 | e->written_uncompressed += l; | |
205 | r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated); | |
206 | } | |
207 | if (r < 0) { | |
208 | r = log_error_errno(r, "Failed to encode: %m"); | |
209 | goto finish; | |
210 | } | |
211 | } | |
212 | ||
213 | l = write(e->output_fd, e->buffer, e->buffer_size); | |
214 | if (l < 0) { | |
215 | if (errno == EAGAIN) | |
216 | return 0; | |
217 | ||
218 | r = log_error_errno(errno, "Failed to write output file: %m"); | |
219 | goto finish; | |
220 | } | |
221 | ||
222 | assert((size_t) l <= e->buffer_size); | |
223 | memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l); | |
224 | e->buffer_size -= l; | |
225 | e->written_compressed += l; | |
226 | ||
227 | tar_export_report_progress(e); | |
228 | ||
229 | return 0; | |
230 | ||
231 | finish: | |
232 | if (e->on_finished) | |
233 | e->on_finished(e, r, e->userdata); | |
234 | else | |
235 | sd_event_exit(e->event, r); | |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
240 | static int tar_export_on_output(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
241 | TarExport *i = userdata; | |
242 | ||
243 | return tar_export_process(i); | |
244 | } | |
245 | ||
246 | static int tar_export_on_defer(sd_event_source *s, void *userdata) { | |
247 | TarExport *i = userdata; | |
248 | ||
249 | return tar_export_process(i); | |
250 | } | |
251 | ||
252 | int tar_export_start(TarExport *e, const char *path, int fd, ImportCompressType compress) { | |
253 | _cleanup_close_ int sfd = -1; | |
254 | int r; | |
255 | ||
256 | assert(e); | |
257 | assert(path); | |
258 | assert(fd >= 0); | |
259 | assert(compress < _IMPORT_COMPRESS_TYPE_MAX); | |
260 | assert(compress != IMPORT_COMPRESS_UNKNOWN); | |
261 | ||
262 | if (e->output_fd >= 0) | |
263 | return -EBUSY; | |
264 | ||
265 | sfd = open(path, O_DIRECTORY|O_RDONLY|O_NOCTTY|O_CLOEXEC); | |
266 | if (sfd < 0) | |
267 | return -errno; | |
268 | ||
269 | if (fstat(sfd, &e->st) < 0) | |
270 | return -errno; | |
271 | ||
272 | r = fd_nonblock(fd, true); | |
273 | if (r < 0) | |
274 | return r; | |
275 | ||
276 | r = free_and_strdup(&e->path, path); | |
277 | if (r < 0) | |
278 | return r; | |
279 | ||
280 | e->quota_referenced = (uint64_t) -1; | |
281 | ||
282 | if (e->st.st_ino == 256) { /* might be a btrfs subvolume? */ | |
283 | BtrfsQuotaInfo q; | |
284 | ||
285 | r = btrfs_subvol_get_quota_fd(sfd, &q); | |
286 | if (r >= 0) | |
cb81cd80 | 287 | e->quota_referenced = q.referenced; |
587fec42 LP |
288 | |
289 | free(e->temp_path); | |
290 | e->temp_path = NULL; | |
291 | ||
292 | r = tempfn_random(path, &e->temp_path); | |
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 */ | |
e9bc1871 | 297 | r = btrfs_subvol_snapshot_fd(sfd, e->temp_path, BTRFS_SNAPSHOT_READ_ONLY); |
587fec42 LP |
298 | if (r < 0) { |
299 | log_debug_errno(r, "Couldn't create snapshot %s of %s, not exporting atomically: %m", e->temp_path, path); | |
300 | free(e->temp_path); | |
301 | e->temp_path = NULL; | |
302 | } | |
303 | } | |
304 | ||
305 | r = import_compress_init(&e->compress, compress); | |
306 | if (r < 0) | |
307 | return r; | |
308 | ||
309 | r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, tar_export_on_output, e); | |
310 | if (r == -EPERM) { | |
311 | r = sd_event_add_defer(e->event, &e->output_event_source, tar_export_on_defer, e); | |
312 | if (r < 0) | |
313 | return r; | |
314 | ||
315 | r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON); | |
316 | } | |
317 | if (r < 0) | |
318 | return r; | |
319 | ||
320 | e->tar_fd = import_fork_tar_c(e->temp_path ?: e->path, &e->tar_pid); | |
321 | if (e->tar_fd < 0) { | |
322 | e->output_event_source = sd_event_source_unref(e->output_event_source); | |
323 | return e->tar_fd; | |
324 | } | |
325 | ||
326 | e->output_fd = fd; | |
327 | return r; | |
328 | } |