Line data Source code
1 : /*
2 : * file.c
3 : *
4 : * file system operations
5 : *
6 : * Copyright (c) 2010-2023, PostgreSQL Global Development Group
7 : * src/bin/pg_upgrade/file.c
8 : */
9 :
10 : #include "postgres_fe.h"
11 :
12 : #include <sys/stat.h>
13 : #include <fcntl.h>
14 : #ifdef HAVE_COPYFILE_H
15 : #include <copyfile.h>
16 : #endif
17 : #ifdef __linux__
18 : #include <sys/ioctl.h>
19 : #include <linux/fs.h>
20 : #endif
21 :
22 : #include "access/visibilitymapdefs.h"
23 : #include "common/file_perm.h"
24 : #include "pg_upgrade.h"
25 : #include "storage/bufpage.h"
26 : #include "storage/checksum.h"
27 : #include "storage/checksum_impl.h"
28 :
29 :
30 : /*
31 : * cloneFile()
32 : *
33 : * Clones/reflinks a relation file from src to dst.
34 : *
35 : * schemaName/relName are relation's SQL name (used for error messages only).
36 : */
37 : void
38 0 : cloneFile(const char *src, const char *dst,
39 : const char *schemaName, const char *relName)
40 : {
41 : #if defined(HAVE_COPYFILE) && defined(COPYFILE_CLONE_FORCE)
42 : if (copyfile(src, dst, NULL, COPYFILE_CLONE_FORCE) < 0)
43 : pg_fatal("error while cloning relation \"%s.%s\" (\"%s\" to \"%s\"): %s",
44 : schemaName, relName, src, dst, strerror(errno));
45 : #elif defined(__linux__) && defined(FICLONE)
46 : int src_fd;
47 : int dest_fd;
48 :
49 0 : if ((src_fd = open(src, O_RDONLY | PG_BINARY, 0)) < 0)
50 0 : pg_fatal("error while cloning relation \"%s.%s\": could not open file \"%s\": %s",
51 0 : schemaName, relName, src, strerror(errno));
52 :
53 0 : if ((dest_fd = open(dst, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
54 : pg_file_create_mode)) < 0)
55 0 : pg_fatal("error while cloning relation \"%s.%s\": could not create file \"%s\": %s",
56 0 : schemaName, relName, dst, strerror(errno));
57 :
58 0 : if (ioctl(dest_fd, FICLONE, src_fd) < 0)
59 : {
60 0 : int save_errno = errno;
61 :
62 0 : unlink(dst);
63 :
64 0 : pg_fatal("error while cloning relation \"%s.%s\" (\"%s\" to \"%s\"): %s",
65 : schemaName, relName, src, dst, strerror(save_errno));
66 : }
67 :
68 0 : close(src_fd);
69 0 : close(dest_fd);
70 : #endif
71 0 : }
72 :
73 :
74 : /*
75 : * copyFile()
76 : *
77 : * Copies a relation file from src to dst.
78 : * schemaName/relName are relation's SQL name (used for error messages only).
79 : */
80 : void
81 3132 : copyFile(const char *src, const char *dst,
82 : const char *schemaName, const char *relName)
83 : {
84 : #ifndef WIN32
85 : int src_fd;
86 : int dest_fd;
87 : char *buffer;
88 :
89 3132 : if ((src_fd = open(src, O_RDONLY | PG_BINARY, 0)) < 0)
90 0 : pg_fatal("error while copying relation \"%s.%s\": could not open file \"%s\": %s",
91 0 : schemaName, relName, src, strerror(errno));
92 :
93 3132 : if ((dest_fd = open(dst, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
94 : pg_file_create_mode)) < 0)
95 0 : pg_fatal("error while copying relation \"%s.%s\": could not create file \"%s\": %s",
96 0 : schemaName, relName, dst, strerror(errno));
97 :
98 : /* copy in fairly large chunks for best efficiency */
99 : #define COPY_BUF_SIZE (50 * BLCKSZ)
100 :
101 3132 : buffer = (char *) pg_malloc(COPY_BUF_SIZE);
102 :
103 : /* perform data copying i.e read src source, write to destination */
104 : while (true)
105 2584 : {
106 5716 : ssize_t nbytes = read(src_fd, buffer, COPY_BUF_SIZE);
107 :
108 5716 : if (nbytes < 0)
109 0 : pg_fatal("error while copying relation \"%s.%s\": could not read file \"%s\": %s",
110 0 : schemaName, relName, src, strerror(errno));
111 :
112 5716 : if (nbytes == 0)
113 3132 : break;
114 :
115 2584 : errno = 0;
116 2584 : if (write(dest_fd, buffer, nbytes) != nbytes)
117 : {
118 : /* if write didn't set errno, assume problem is no disk space */
119 0 : if (errno == 0)
120 0 : errno = ENOSPC;
121 0 : pg_fatal("error while copying relation \"%s.%s\": could not write file \"%s\": %s",
122 0 : schemaName, relName, dst, strerror(errno));
123 : }
124 : }
125 :
126 3132 : pg_free(buffer);
127 3132 : close(src_fd);
128 3132 : close(dest_fd);
129 :
130 : #else /* WIN32 */
131 :
132 : if (CopyFile(src, dst, true) == 0)
133 : {
134 : _dosmaperr(GetLastError());
135 : pg_fatal("error while copying relation \"%s.%s\" (\"%s\" to \"%s\"): %s",
136 : schemaName, relName, src, dst, strerror(errno));
137 : }
138 :
139 : #endif /* WIN32 */
140 3132 : }
141 :
142 :
143 : /*
144 : * linkFile()
145 : *
146 : * Hard-links a relation file from src to dst.
147 : * schemaName/relName are relation's SQL name (used for error messages only).
148 : */
149 : void
150 0 : linkFile(const char *src, const char *dst,
151 : const char *schemaName, const char *relName)
152 : {
153 0 : if (link(src, dst) < 0)
154 0 : pg_fatal("error while creating link for relation \"%s.%s\" (\"%s\" to \"%s\"): %s",
155 0 : schemaName, relName, src, dst, strerror(errno));
156 0 : }
157 :
158 :
159 : /*
160 : * rewriteVisibilityMap()
161 : *
162 : * Transform a visibility map file, copying from src to dst.
163 : * schemaName/relName are relation's SQL name (used for error messages only).
164 : *
165 : * In versions of PostgreSQL prior to catversion 201603011, PostgreSQL's
166 : * visibility map included one bit per heap page; it now includes two.
167 : * When upgrading a cluster from before that time to a current PostgreSQL
168 : * version, we could refuse to copy visibility maps from the old cluster
169 : * to the new cluster; the next VACUUM would recreate them, but at the
170 : * price of scanning the entire table. So, instead, we rewrite the old
171 : * visibility maps in the new format. That way, the all-visible bits
172 : * remain set for the pages for which they were set previously. The
173 : * all-frozen bits are never set by this conversion; we leave that to VACUUM.
174 : */
175 : void
176 0 : rewriteVisibilityMap(const char *fromfile, const char *tofile,
177 : const char *schemaName, const char *relName)
178 : {
179 : int src_fd;
180 : int dst_fd;
181 : PGIOAlignedBlock buffer;
182 : PGIOAlignedBlock new_vmbuf;
183 0 : ssize_t totalBytesRead = 0;
184 : ssize_t src_filesize;
185 : int rewriteVmBytesPerPage;
186 0 : BlockNumber new_blkno = 0;
187 : struct stat statbuf;
188 :
189 : /* Compute number of old-format bytes per new page */
190 0 : rewriteVmBytesPerPage = (BLCKSZ - SizeOfPageHeaderData) / 2;
191 :
192 0 : if ((src_fd = open(fromfile, O_RDONLY | PG_BINARY, 0)) < 0)
193 0 : pg_fatal("error while copying relation \"%s.%s\": could not open file \"%s\": %s",
194 0 : schemaName, relName, fromfile, strerror(errno));
195 :
196 0 : if (fstat(src_fd, &statbuf) != 0)
197 0 : pg_fatal("error while copying relation \"%s.%s\": could not stat file \"%s\": %s",
198 0 : schemaName, relName, fromfile, strerror(errno));
199 :
200 0 : if ((dst_fd = open(tofile, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
201 : pg_file_create_mode)) < 0)
202 0 : pg_fatal("error while copying relation \"%s.%s\": could not create file \"%s\": %s",
203 0 : schemaName, relName, tofile, strerror(errno));
204 :
205 : /* Save old file size */
206 0 : src_filesize = statbuf.st_size;
207 :
208 : /*
209 : * Turn each visibility map page into 2 pages one by one. Each new page
210 : * has the same page header as the old one. If the last section of the
211 : * last page is empty, we skip it, mostly to avoid turning one-page
212 : * visibility maps for small relations into two pages needlessly.
213 : */
214 0 : while (totalBytesRead < src_filesize)
215 : {
216 : ssize_t bytesRead;
217 : char *old_cur;
218 : char *old_break;
219 : char *old_blkend;
220 : PageHeaderData pageheader;
221 : bool old_lastblk;
222 :
223 0 : if ((bytesRead = read(src_fd, buffer.data, BLCKSZ)) != BLCKSZ)
224 : {
225 0 : if (bytesRead < 0)
226 0 : pg_fatal("error while copying relation \"%s.%s\": could not read file \"%s\": %s",
227 0 : schemaName, relName, fromfile, strerror(errno));
228 : else
229 0 : pg_fatal("error while copying relation \"%s.%s\": partial page found in file \"%s\"",
230 : schemaName, relName, fromfile);
231 : }
232 :
233 0 : totalBytesRead += BLCKSZ;
234 0 : old_lastblk = (totalBytesRead == src_filesize);
235 :
236 : /* Save the page header data */
237 0 : memcpy(&pageheader, buffer.data, SizeOfPageHeaderData);
238 :
239 : /*
240 : * These old_* variables point to old visibility map page. old_cur
241 : * points to current position on old page. old_blkend points to end of
242 : * old block. old_break is the end+1 position on the old page for the
243 : * data that will be transferred to the current new page.
244 : */
245 0 : old_cur = buffer.data + SizeOfPageHeaderData;
246 0 : old_blkend = buffer.data + bytesRead;
247 0 : old_break = old_cur + rewriteVmBytesPerPage;
248 :
249 0 : while (old_break <= old_blkend)
250 : {
251 : char *new_cur;
252 0 : bool empty = true;
253 : bool old_lastpart;
254 :
255 : /* First, copy old page header to new page */
256 0 : memcpy(new_vmbuf.data, &pageheader, SizeOfPageHeaderData);
257 :
258 : /* Rewriting the last part of the last old page? */
259 0 : old_lastpart = old_lastblk && (old_break == old_blkend);
260 :
261 0 : new_cur = new_vmbuf.data + SizeOfPageHeaderData;
262 :
263 : /* Process old page bytes one by one, and turn it into new page. */
264 0 : while (old_cur < old_break)
265 : {
266 0 : uint8 byte = *(uint8 *) old_cur;
267 0 : uint16 new_vmbits = 0;
268 : int i;
269 :
270 : /* Generate new format bits while keeping old information */
271 0 : for (i = 0; i < BITS_PER_BYTE; i++)
272 : {
273 0 : if (byte & (1 << i))
274 : {
275 0 : empty = false;
276 0 : new_vmbits |=
277 0 : VISIBILITYMAP_ALL_VISIBLE << (BITS_PER_HEAPBLOCK * i);
278 : }
279 : }
280 :
281 : /* Copy new visibility map bytes to new-format page */
282 0 : new_cur[0] = (char) (new_vmbits & 0xFF);
283 0 : new_cur[1] = (char) (new_vmbits >> 8);
284 :
285 0 : old_cur++;
286 0 : new_cur += BITS_PER_HEAPBLOCK;
287 : }
288 :
289 : /* If the last part of the last page is empty, skip writing it */
290 0 : if (old_lastpart && empty)
291 0 : break;
292 :
293 : /* Set new checksum for visibility map page, if enabled */
294 0 : if (new_cluster.controldata.data_checksum_version != 0)
295 0 : ((PageHeader) new_vmbuf.data)->pd_checksum =
296 0 : pg_checksum_page(new_vmbuf.data, new_blkno);
297 :
298 0 : errno = 0;
299 0 : if (write(dst_fd, new_vmbuf.data, BLCKSZ) != BLCKSZ)
300 : {
301 : /* if write didn't set errno, assume problem is no disk space */
302 0 : if (errno == 0)
303 0 : errno = ENOSPC;
304 0 : pg_fatal("error while copying relation \"%s.%s\": could not write file \"%s\": %s",
305 0 : schemaName, relName, tofile, strerror(errno));
306 : }
307 :
308 : /* Advance for next new page */
309 0 : old_break += rewriteVmBytesPerPage;
310 0 : new_blkno++;
311 : }
312 : }
313 :
314 : /* Clean up */
315 0 : close(dst_fd);
316 0 : close(src_fd);
317 0 : }
318 :
319 : void
320 0 : check_file_clone(void)
321 : {
322 : char existing_file[MAXPGPATH];
323 : char new_link_file[MAXPGPATH];
324 :
325 0 : snprintf(existing_file, sizeof(existing_file), "%s/PG_VERSION", old_cluster.pgdata);
326 0 : snprintf(new_link_file, sizeof(new_link_file), "%s/PG_VERSION.clonetest", new_cluster.pgdata);
327 0 : unlink(new_link_file); /* might fail */
328 :
329 : #if defined(HAVE_COPYFILE) && defined(COPYFILE_CLONE_FORCE)
330 : if (copyfile(existing_file, new_link_file, NULL, COPYFILE_CLONE_FORCE) < 0)
331 : pg_fatal("could not clone file between old and new data directories: %s",
332 : strerror(errno));
333 : #elif defined(__linux__) && defined(FICLONE)
334 : {
335 : int src_fd;
336 : int dest_fd;
337 :
338 0 : if ((src_fd = open(existing_file, O_RDONLY | PG_BINARY, 0)) < 0)
339 0 : pg_fatal("could not open file \"%s\": %s",
340 0 : existing_file, strerror(errno));
341 :
342 0 : if ((dest_fd = open(new_link_file, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
343 : pg_file_create_mode)) < 0)
344 0 : pg_fatal("could not create file \"%s\": %s",
345 0 : new_link_file, strerror(errno));
346 :
347 0 : if (ioctl(dest_fd, FICLONE, src_fd) < 0)
348 0 : pg_fatal("could not clone file between old and new data directories: %s",
349 0 : strerror(errno));
350 :
351 0 : close(src_fd);
352 0 : close(dest_fd);
353 : }
354 : #else
355 : pg_fatal("file cloning not supported on this platform");
356 : #endif
357 :
358 0 : unlink(new_link_file);
359 0 : }
360 :
361 : void
362 0 : check_hard_link(void)
363 : {
364 : char existing_file[MAXPGPATH];
365 : char new_link_file[MAXPGPATH];
366 :
367 0 : snprintf(existing_file, sizeof(existing_file), "%s/PG_VERSION", old_cluster.pgdata);
368 0 : snprintf(new_link_file, sizeof(new_link_file), "%s/PG_VERSION.linktest", new_cluster.pgdata);
369 0 : unlink(new_link_file); /* might fail */
370 :
371 0 : if (link(existing_file, new_link_file) < 0)
372 0 : pg_fatal("could not create hard link between old and new data directories: %s\n"
373 : "In link mode the old and new data directories must be on the same file system.",
374 0 : strerror(errno));
375 :
376 0 : unlink(new_link_file);
377 0 : }
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