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587fec42 LP |
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 | #include <libgen.h> | |
24 | #undef basename | |
25 | ||
26 | #include "sd-daemon.h" | |
07630cea | 27 | |
587fec42 LP |
28 | #include "btrfs-util.h" |
29 | #include "copy.h" | |
587fec42 | 30 | #include "export-raw.h" |
3ffd4af2 | 31 | #include "fd-util.h" |
07630cea LP |
32 | #include "import-common.h" |
33 | #include "ratelimit.h" | |
34 | #include "string-util.h" | |
35 | #include "util.h" | |
587fec42 LP |
36 | |
37 | #define COPY_BUFFER_SIZE (16*1024) | |
38 | ||
39 | struct RawExport { | |
40 | sd_event *event; | |
41 | ||
42 | RawExportFinished on_finished; | |
43 | void *userdata; | |
44 | ||
45 | char *path; | |
46 | ||
47 | int input_fd; | |
48 | int output_fd; | |
49 | ||
50 | ImportCompress compress; | |
51 | ||
52 | sd_event_source *output_event_source; | |
53 | ||
54 | void *buffer; | |
55 | size_t buffer_size; | |
56 | size_t buffer_allocated; | |
57 | ||
58 | uint64_t written_compressed; | |
59 | uint64_t written_uncompressed; | |
60 | ||
61 | unsigned last_percent; | |
62 | RateLimit progress_rate_limit; | |
63 | ||
64 | struct stat st; | |
65 | ||
66 | bool eof; | |
67 | bool tried_reflink; | |
68 | bool tried_sendfile; | |
69 | }; | |
70 | ||
71 | RawExport *raw_export_unref(RawExport *e) { | |
72 | if (!e) | |
73 | return NULL; | |
74 | ||
75 | sd_event_source_unref(e->output_event_source); | |
76 | ||
77 | import_compress_free(&e->compress); | |
78 | ||
79 | sd_event_unref(e->event); | |
80 | ||
81 | safe_close(e->input_fd); | |
82 | ||
83 | free(e->buffer); | |
84 | free(e->path); | |
85 | free(e); | |
86 | ||
87 | return NULL; | |
88 | } | |
89 | ||
90 | int raw_export_new( | |
91 | RawExport **ret, | |
92 | sd_event *event, | |
93 | RawExportFinished on_finished, | |
94 | void *userdata) { | |
95 | ||
96 | _cleanup_(raw_export_unrefp) RawExport *e = NULL; | |
97 | int r; | |
98 | ||
99 | assert(ret); | |
100 | ||
101 | e = new0(RawExport, 1); | |
102 | if (!e) | |
103 | return -ENOMEM; | |
104 | ||
105 | e->output_fd = e->input_fd = -1; | |
106 | e->on_finished = on_finished; | |
107 | e->userdata = userdata; | |
108 | ||
109 | RATELIMIT_INIT(e->progress_rate_limit, 100 * USEC_PER_MSEC, 1); | |
110 | e->last_percent = (unsigned) -1; | |
111 | ||
112 | if (event) | |
113 | e->event = sd_event_ref(event); | |
114 | else { | |
115 | r = sd_event_default(&e->event); | |
116 | if (r < 0) | |
117 | return r; | |
118 | } | |
119 | ||
120 | *ret = e; | |
121 | e = NULL; | |
122 | ||
123 | return 0; | |
124 | } | |
125 | ||
126 | static void raw_export_report_progress(RawExport *e) { | |
127 | unsigned percent; | |
128 | assert(e); | |
129 | ||
130 | if (e->written_uncompressed >= (uint64_t) e->st.st_size) | |
131 | percent = 100; | |
132 | else | |
133 | percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / (uint64_t) e->st.st_size); | |
134 | ||
135 | if (percent == e->last_percent) | |
136 | return; | |
137 | ||
138 | if (!ratelimit_test(&e->progress_rate_limit)) | |
139 | return; | |
140 | ||
141 | sd_notifyf(false, "X_IMPORT_PROGRESS=%u", percent); | |
142 | log_info("Exported %u%%.", percent); | |
143 | ||
144 | e->last_percent = percent; | |
145 | } | |
146 | ||
147 | static int raw_export_process(RawExport *e) { | |
148 | ssize_t l; | |
149 | int r; | |
150 | ||
151 | assert(e); | |
152 | ||
153 | if (!e->tried_reflink && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) { | |
154 | ||
155 | /* If we shall take an uncompressed snapshot we can | |
156 | * reflink source to destination directly. Let's see | |
157 | * if this works. */ | |
158 | ||
159 | r = btrfs_reflink(e->input_fd, e->output_fd); | |
160 | if (r >= 0) { | |
161 | r = 0; | |
162 | goto finish; | |
163 | } | |
164 | ||
165 | e->tried_reflink = true; | |
166 | } | |
167 | ||
168 | if (!e->tried_sendfile && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) { | |
169 | ||
170 | l = sendfile(e->output_fd, e->input_fd, NULL, COPY_BUFFER_SIZE); | |
171 | if (l < 0) { | |
172 | if (errno == EAGAIN) | |
173 | return 0; | |
174 | ||
175 | e->tried_sendfile = true; | |
176 | } else if (l == 0) { | |
177 | r = 0; | |
178 | goto finish; | |
179 | } else { | |
180 | e->written_uncompressed += l; | |
181 | e->written_compressed += l; | |
182 | ||
183 | raw_export_report_progress(e); | |
184 | ||
185 | return 0; | |
186 | } | |
187 | } | |
188 | ||
189 | while (e->buffer_size <= 0) { | |
190 | uint8_t input[COPY_BUFFER_SIZE]; | |
191 | ||
192 | if (e->eof) { | |
193 | r = 0; | |
194 | goto finish; | |
195 | } | |
196 | ||
197 | l = read(e->input_fd, input, sizeof(input)); | |
198 | if (l < 0) { | |
199 | r = log_error_errno(errno, "Failed to read raw file: %m"); | |
200 | goto finish; | |
201 | } | |
202 | ||
203 | if (l == 0) { | |
204 | e->eof = true; | |
205 | r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated); | |
206 | } else { | |
207 | e->written_uncompressed += l; | |
208 | r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated); | |
209 | } | |
210 | if (r < 0) { | |
211 | r = log_error_errno(r, "Failed to encode: %m"); | |
212 | goto finish; | |
213 | } | |
214 | } | |
215 | ||
216 | l = write(e->output_fd, e->buffer, e->buffer_size); | |
217 | if (l < 0) { | |
218 | if (errno == EAGAIN) | |
219 | return 0; | |
220 | ||
221 | r = log_error_errno(errno, "Failed to write output file: %m"); | |
222 | goto finish; | |
223 | } | |
224 | ||
225 | assert((size_t) l <= e->buffer_size); | |
226 | memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l); | |
227 | e->buffer_size -= l; | |
228 | e->written_compressed += l; | |
229 | ||
230 | raw_export_report_progress(e); | |
231 | ||
232 | return 0; | |
233 | ||
234 | finish: | |
235 | if (r >= 0) { | |
236 | (void) copy_times(e->input_fd, e->output_fd); | |
237 | (void) copy_xattr(e->input_fd, e->output_fd); | |
238 | } | |
239 | ||
240 | if (e->on_finished) | |
241 | e->on_finished(e, r, e->userdata); | |
242 | else | |
243 | sd_event_exit(e->event, r); | |
244 | ||
245 | return 0; | |
246 | } | |
247 | ||
248 | static int raw_export_on_output(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
249 | RawExport *i = userdata; | |
250 | ||
251 | return raw_export_process(i); | |
252 | } | |
253 | ||
254 | static int raw_export_on_defer(sd_event_source *s, void *userdata) { | |
255 | RawExport *i = userdata; | |
256 | ||
257 | return raw_export_process(i); | |
258 | } | |
259 | ||
260 | static int reflink_snapshot(int fd, const char *path) { | |
261 | char *p, *d; | |
262 | int new_fd, r; | |
263 | ||
264 | p = strdupa(path); | |
265 | d = dirname(p); | |
266 | ||
267 | new_fd = open(d, O_TMPFILE|O_CLOEXEC|O_NOCTTY|O_RDWR, 0600); | |
268 | if (new_fd < 0) { | |
269 | _cleanup_free_ char *t = NULL; | |
270 | ||
14bcf25c | 271 | r = tempfn_random(path, NULL, &t); |
587fec42 LP |
272 | if (r < 0) |
273 | return r; | |
274 | ||
275 | new_fd = open(t, O_CLOEXEC|O_CREAT|O_NOCTTY|O_RDWR, 0600); | |
276 | if (new_fd < 0) | |
277 | return -errno; | |
278 | ||
279 | (void) unlink(t); | |
280 | } | |
281 | ||
282 | r = btrfs_reflink(fd, new_fd); | |
283 | if (r < 0) { | |
284 | safe_close(new_fd); | |
285 | return r; | |
286 | } | |
287 | ||
288 | return new_fd; | |
289 | } | |
290 | ||
291 | int raw_export_start(RawExport *e, const char *path, int fd, ImportCompressType compress) { | |
292 | _cleanup_close_ int sfd = -1, tfd = -1; | |
293 | int r; | |
294 | ||
295 | assert(e); | |
296 | assert(path); | |
297 | assert(fd >= 0); | |
298 | assert(compress < _IMPORT_COMPRESS_TYPE_MAX); | |
299 | assert(compress != IMPORT_COMPRESS_UNKNOWN); | |
300 | ||
301 | if (e->output_fd >= 0) | |
302 | return -EBUSY; | |
303 | ||
304 | r = fd_nonblock(fd, true); | |
305 | if (r < 0) | |
306 | return r; | |
307 | ||
308 | r = free_and_strdup(&e->path, path); | |
309 | if (r < 0) | |
310 | return r; | |
311 | ||
312 | sfd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY); | |
313 | if (sfd < 0) | |
314 | return -errno; | |
315 | ||
316 | if (fstat(sfd, &e->st) < 0) | |
317 | return -errno; | |
318 | if (!S_ISREG(e->st.st_mode)) | |
319 | return -ENOTTY; | |
320 | ||
321 | /* Try to take a reflink snapshot of the file, if we can t make the export atomic */ | |
322 | tfd = reflink_snapshot(sfd, path); | |
323 | if (tfd >= 0) { | |
324 | e->input_fd = tfd; | |
325 | tfd = -1; | |
326 | } else { | |
327 | e->input_fd = sfd; | |
328 | sfd = -1; | |
329 | } | |
330 | ||
331 | r = import_compress_init(&e->compress, compress); | |
332 | if (r < 0) | |
333 | return r; | |
334 | ||
335 | r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, raw_export_on_output, e); | |
336 | if (r == -EPERM) { | |
337 | r = sd_event_add_defer(e->event, &e->output_event_source, raw_export_on_defer, e); | |
338 | if (r < 0) | |
339 | return r; | |
340 | ||
341 | r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON); | |
342 | } | |
343 | if (r < 0) | |
344 | return r; | |
345 | ||
346 | e->output_fd = fd; | |
347 | return r; | |
348 | } |