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