1 /*
2  *	relfilenode.c
3  *
4  *	relfilenode functions
5  *
6  *	Copyright (c) 2010-2019, PostgreSQL Global Development Group
7  *	src/bin/pg_upgrade/relfilenode.c
8  */
9 
10 #include "postgres_fe.h"
11 
12 #include "pg_upgrade.h"
13 
14 #include <sys/stat.h>
15 #include "catalog/pg_class_d.h"
16 #include "access/transam.h"
17 
18 
19 static void transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace);
20 static void transfer_relfile(FileNameMap *map, const char *suffix, bool vm_must_add_frozenbit);
21 
22 
23 /*
24  * transfer_all_new_tablespaces()
25  *
26  * Responsible for upgrading all database. invokes routines to generate mappings and then
27  * physically link the databases.
28  */
29 void
30 transfer_all_new_tablespaces(DbInfoArr *old_db_arr, DbInfoArr *new_db_arr,
31 							 char *old_pgdata, char *new_pgdata)
32 {
33 	switch (user_opts.transfer_mode)
34 	{
35 		case TRANSFER_MODE_CLONE:
36 			pg_log(PG_REPORT, "Cloning user relation files\n");
37 			break;
38 		case TRANSFER_MODE_COPY:
39 			pg_log(PG_REPORT, "Copying user relation files\n");
40 			break;
41 		case TRANSFER_MODE_LINK:
42 			pg_log(PG_REPORT, "Linking user relation files\n");
43 			break;
44 	}
45 
46 	/*
47 	 * Transferring files by tablespace is tricky because a single database
48 	 * can use multiple tablespaces.  For non-parallel mode, we just pass a
49 	 * NULL tablespace path, which matches all tablespaces.  In parallel mode,
50 	 * we pass the default tablespace and all user-created tablespaces and let
51 	 * those operations happen in parallel.
52 	 */
53 	if (user_opts.jobs <= 1)
54 		parallel_transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata,
55 									  new_pgdata, NULL);
56 	else
57 	{
58 		int			tblnum;
59 
60 		/* transfer default tablespace */
61 		parallel_transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata,
62 									  new_pgdata, old_pgdata);
63 
64 		for (tblnum = 0; tblnum < os_info.num_old_tablespaces; tblnum++)
65 			parallel_transfer_all_new_dbs(old_db_arr,
66 										  new_db_arr,
67 										  old_pgdata,
68 										  new_pgdata,
69 										  os_info.old_tablespaces[tblnum]);
70 		/* reap all children */
71 		while (reap_child(true) == true)
72 			;
73 	}
74 
75 	end_progress_output();
76 	check_ok();
77 
78 	return;
79 }
80 
81 
82 /*
83  * transfer_all_new_dbs()
84  *
85  * Responsible for upgrading all database. invokes routines to generate mappings and then
86  * physically link the databases.
87  */
88 void
89 transfer_all_new_dbs(DbInfoArr *old_db_arr, DbInfoArr *new_db_arr,
90 					 char *old_pgdata, char *new_pgdata, char *old_tablespace)
91 {
92 	int			old_dbnum,
93 				new_dbnum;
94 
95 	/* Scan the old cluster databases and transfer their files */
96 	for (old_dbnum = new_dbnum = 0;
97 		 old_dbnum < old_db_arr->ndbs;
98 		 old_dbnum++, new_dbnum++)
99 	{
100 		DbInfo	   *old_db = &old_db_arr->dbs[old_dbnum],
101 				   *new_db = NULL;
102 		FileNameMap *mappings;
103 		int			n_maps;
104 
105 		/*
106 		 * Advance past any databases that exist in the new cluster but not in
107 		 * the old, e.g. "postgres".  (The user might have removed the
108 		 * 'postgres' database from the old cluster.)
109 		 */
110 		for (; new_dbnum < new_db_arr->ndbs; new_dbnum++)
111 		{
112 			new_db = &new_db_arr->dbs[new_dbnum];
113 			if (strcmp(old_db->db_name, new_db->db_name) == 0)
114 				break;
115 		}
116 
117 		if (new_dbnum >= new_db_arr->ndbs)
118 			pg_fatal("old database \"%s\" not found in the new cluster\n",
119 					 old_db->db_name);
120 
121 		mappings = gen_db_file_maps(old_db, new_db, &n_maps, old_pgdata,
122 									new_pgdata);
123 		if (n_maps)
124 		{
125 			print_maps(mappings, n_maps, new_db->db_name);
126 
127 			transfer_single_new_db(mappings, n_maps, old_tablespace);
128 		}
129 		/* We allocate something even for n_maps == 0 */
130 		pg_free(mappings);
131 	}
132 
133 	return;
134 }
135 
136 /*
137  * transfer_single_new_db()
138  *
139  * create links for mappings stored in "maps" array.
140  */
141 static void
142 transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace)
143 {
144 	int			mapnum;
145 	bool		vm_crashsafe_match = true;
146 	bool		vm_must_add_frozenbit = false;
147 
148 	/*
149 	 * Do the old and new cluster disagree on the crash-safetiness of the vm
150 	 * files?  If so, do not copy them.
151 	 */
152 	if (old_cluster.controldata.cat_ver < VISIBILITY_MAP_CRASHSAFE_CAT_VER &&
153 		new_cluster.controldata.cat_ver >= VISIBILITY_MAP_CRASHSAFE_CAT_VER)
154 		vm_crashsafe_match = false;
155 
156 	/*
157 	 * Do we need to rewrite visibilitymap?
158 	 */
159 	if (old_cluster.controldata.cat_ver < VISIBILITY_MAP_FROZEN_BIT_CAT_VER &&
160 		new_cluster.controldata.cat_ver >= VISIBILITY_MAP_FROZEN_BIT_CAT_VER)
161 		vm_must_add_frozenbit = true;
162 
163 	for (mapnum = 0; mapnum < size; mapnum++)
164 	{
165 		if (old_tablespace == NULL ||
166 			strcmp(maps[mapnum].old_tablespace, old_tablespace) == 0)
167 		{
168 			/* transfer primary file */
169 			transfer_relfile(&maps[mapnum], "", vm_must_add_frozenbit);
170 
171 			/*
172 			 * Copy/link any fsm and vm files, if they exist
173 			 */
174 			transfer_relfile(&maps[mapnum], "_fsm", vm_must_add_frozenbit);
175 			if (vm_crashsafe_match)
176 				transfer_relfile(&maps[mapnum], "_vm", vm_must_add_frozenbit);
177 		}
178 	}
179 }
180 
181 
182 /*
183  * transfer_relfile()
184  *
185  * Copy or link file from old cluster to new one.  If vm_must_add_frozenbit
186  * is true, visibility map forks are converted and rewritten, even in link
187  * mode.
188  */
189 static void
190 transfer_relfile(FileNameMap *map, const char *type_suffix, bool vm_must_add_frozenbit)
191 {
192 	char		old_file[MAXPGPATH];
193 	char		new_file[MAXPGPATH];
194 	int			segno;
195 	char		extent_suffix[65];
196 	struct stat statbuf;
197 
198 	/*
199 	 * Now copy/link any related segments as well. Remember, PG breaks large
200 	 * files into 1GB segments, the first segment has no extension, subsequent
201 	 * segments are named relfilenode.1, relfilenode.2, relfilenode.3.
202 	 */
203 	for (segno = 0;; segno++)
204 	{
205 		if (segno == 0)
206 			extent_suffix[0] = '\0';
207 		else
208 			snprintf(extent_suffix, sizeof(extent_suffix), ".%d", segno);
209 
210 		snprintf(old_file, sizeof(old_file), "%s%s/%u/%u%s%s",
211 				 map->old_tablespace,
212 				 map->old_tablespace_suffix,
213 				 map->old_db_oid,
214 				 map->old_relfilenode,
215 				 type_suffix,
216 				 extent_suffix);
217 		snprintf(new_file, sizeof(new_file), "%s%s/%u/%u%s%s",
218 				 map->new_tablespace,
219 				 map->new_tablespace_suffix,
220 				 map->new_db_oid,
221 				 map->new_relfilenode,
222 				 type_suffix,
223 				 extent_suffix);
224 
225 		/* Is it an extent, fsm, or vm file? */
226 		if (type_suffix[0] != '\0' || segno != 0)
227 		{
228 			/* Did file open fail? */
229 			if (stat(old_file, &statbuf) != 0)
230 			{
231 				/* File does not exist?  That's OK, just return */
232 				if (errno == ENOENT)
233 					return;
234 				else
235 					pg_fatal("error while checking for file existence \"%s.%s\" (\"%s\" to \"%s\"): %s\n",
236 							 map->nspname, map->relname, old_file, new_file,
237 							 strerror(errno));
238 			}
239 
240 			/* If file is empty, just return */
241 			if (statbuf.st_size == 0)
242 				return;
243 		}
244 
245 		unlink(new_file);
246 
247 		/* Copying files might take some time, so give feedback. */
248 		pg_log(PG_STATUS, "%s", old_file);
249 
250 		if (vm_must_add_frozenbit && strcmp(type_suffix, "_vm") == 0)
251 		{
252 			/* Need to rewrite visibility map format */
253 			pg_log(PG_VERBOSE, "rewriting \"%s\" to \"%s\"\n",
254 				   old_file, new_file);
255 			rewriteVisibilityMap(old_file, new_file, map->nspname, map->relname);
256 		}
257 		else
258 			switch (user_opts.transfer_mode)
259 			{
260 				case TRANSFER_MODE_CLONE:
261 					pg_log(PG_VERBOSE, "cloning \"%s\" to \"%s\"\n",
262 						   old_file, new_file);
263 					cloneFile(old_file, new_file, map->nspname, map->relname);
264 					break;
265 				case TRANSFER_MODE_COPY:
266 					pg_log(PG_VERBOSE, "copying \"%s\" to \"%s\"\n",
267 						   old_file, new_file);
268 					copyFile(old_file, new_file, map->nspname, map->relname);
269 					break;
270 				case TRANSFER_MODE_LINK:
271 					pg_log(PG_VERBOSE, "linking \"%s\" to \"%s\"\n",
272 						   old_file, new_file);
273 					linkFile(old_file, new_file, map->nspname, map->relname);
274 			}
275 	}
276 }
277