1 /*
2  *	relfilenode.c
3  *
4  *	relfilenode functions
5  *
6  *	Copyright (c) 2010-2020, PostgreSQL Global Development Group
7  *	src/bin/pg_upgrade/relfilenode.c
8  */
9 
10 #include "postgres_fe.h"
11 
12 #include <sys/stat.h>
13 
14 #include "access/transam.h"
15 #include "catalog/pg_class_d.h"
16 #include "pg_upgrade.h"
17 
18 static void transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace);
19 static void transfer_relfile(FileNameMap *map, const char *suffix, bool vm_must_add_frozenbit);
20 
21 
22 /*
23  * transfer_all_new_tablespaces()
24  *
25  * Responsible for upgrading all database. invokes routines to generate mappings and then
26  * physically link the databases.
27  */
28 void
transfer_all_new_tablespaces(DbInfoArr * old_db_arr,DbInfoArr * new_db_arr,char * old_pgdata,char * new_pgdata)29 transfer_all_new_tablespaces(DbInfoArr *old_db_arr, DbInfoArr *new_db_arr,
30 							 char *old_pgdata, char *new_pgdata)
31 {
32 	switch (user_opts.transfer_mode)
33 	{
34 		case TRANSFER_MODE_CLONE:
35 			pg_log(PG_REPORT, "Cloning user relation files\n");
36 			break;
37 		case TRANSFER_MODE_COPY:
38 			pg_log(PG_REPORT, "Copying user relation files\n");
39 			break;
40 		case TRANSFER_MODE_LINK:
41 			pg_log(PG_REPORT, "Linking user relation files\n");
42 			break;
43 	}
44 
45 	/*
46 	 * Transferring files by tablespace is tricky because a single database
47 	 * can use multiple tablespaces.  For non-parallel mode, we just pass a
48 	 * NULL tablespace path, which matches all tablespaces.  In parallel mode,
49 	 * we pass the default tablespace and all user-created tablespaces and let
50 	 * those operations happen in parallel.
51 	 */
52 	if (user_opts.jobs <= 1)
53 		parallel_transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata,
54 									  new_pgdata, NULL);
55 	else
56 	{
57 		int			tblnum;
58 
59 		/* transfer default tablespace */
60 		parallel_transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata,
61 									  new_pgdata, old_pgdata);
62 
63 		for (tblnum = 0; tblnum < os_info.num_old_tablespaces; tblnum++)
64 			parallel_transfer_all_new_dbs(old_db_arr,
65 										  new_db_arr,
66 										  old_pgdata,
67 										  new_pgdata,
68 										  os_info.old_tablespaces[tblnum]);
69 		/* reap all children */
70 		while (reap_child(true) == true)
71 			;
72 	}
73 
74 	end_progress_output();
75 	check_ok();
76 }
77 
78 
79 /*
80  * transfer_all_new_dbs()
81  *
82  * Responsible for upgrading all database. invokes routines to generate mappings and then
83  * physically link the databases.
84  */
85 void
transfer_all_new_dbs(DbInfoArr * old_db_arr,DbInfoArr * new_db_arr,char * old_pgdata,char * new_pgdata,char * old_tablespace)86 transfer_all_new_dbs(DbInfoArr *old_db_arr, DbInfoArr *new_db_arr,
87 					 char *old_pgdata, char *new_pgdata, char *old_tablespace)
88 {
89 	int			old_dbnum,
90 				new_dbnum;
91 
92 	/* Scan the old cluster databases and transfer their files */
93 	for (old_dbnum = new_dbnum = 0;
94 		 old_dbnum < old_db_arr->ndbs;
95 		 old_dbnum++, new_dbnum++)
96 	{
97 		DbInfo	   *old_db = &old_db_arr->dbs[old_dbnum],
98 				   *new_db = NULL;
99 		FileNameMap *mappings;
100 		int			n_maps;
101 
102 		/*
103 		 * Advance past any databases that exist in the new cluster but not in
104 		 * the old, e.g. "postgres".  (The user might have removed the
105 		 * 'postgres' database from the old cluster.)
106 		 */
107 		for (; new_dbnum < new_db_arr->ndbs; new_dbnum++)
108 		{
109 			new_db = &new_db_arr->dbs[new_dbnum];
110 			if (strcmp(old_db->db_name, new_db->db_name) == 0)
111 				break;
112 		}
113 
114 		if (new_dbnum >= new_db_arr->ndbs)
115 			pg_fatal("old database \"%s\" not found in the new cluster\n",
116 					 old_db->db_name);
117 
118 		mappings = gen_db_file_maps(old_db, new_db, &n_maps, old_pgdata,
119 									new_pgdata);
120 		if (n_maps)
121 		{
122 			print_maps(mappings, n_maps, new_db->db_name);
123 
124 			transfer_single_new_db(mappings, n_maps, old_tablespace);
125 		}
126 		/* We allocate something even for n_maps == 0 */
127 		pg_free(mappings);
128 	}
129 }
130 
131 /*
132  * transfer_single_new_db()
133  *
134  * create links for mappings stored in "maps" array.
135  */
136 static void
transfer_single_new_db(FileNameMap * maps,int size,char * old_tablespace)137 transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace)
138 {
139 	int			mapnum;
140 	bool		vm_crashsafe_match = true;
141 	bool		vm_must_add_frozenbit = false;
142 
143 	/*
144 	 * Do the old and new cluster disagree on the crash-safetiness of the vm
145 	 * files?  If so, do not copy them.
146 	 */
147 	if (old_cluster.controldata.cat_ver < VISIBILITY_MAP_CRASHSAFE_CAT_VER &&
148 		new_cluster.controldata.cat_ver >= VISIBILITY_MAP_CRASHSAFE_CAT_VER)
149 		vm_crashsafe_match = false;
150 
151 	/*
152 	 * Do we need to rewrite visibilitymap?
153 	 */
154 	if (old_cluster.controldata.cat_ver < VISIBILITY_MAP_FROZEN_BIT_CAT_VER &&
155 		new_cluster.controldata.cat_ver >= VISIBILITY_MAP_FROZEN_BIT_CAT_VER)
156 		vm_must_add_frozenbit = true;
157 
158 	for (mapnum = 0; mapnum < size; mapnum++)
159 	{
160 		if (old_tablespace == NULL ||
161 			strcmp(maps[mapnum].old_tablespace, old_tablespace) == 0)
162 		{
163 			/* transfer primary file */
164 			transfer_relfile(&maps[mapnum], "", vm_must_add_frozenbit);
165 
166 			/*
167 			 * Copy/link any fsm and vm files, if they exist
168 			 */
169 			transfer_relfile(&maps[mapnum], "_fsm", vm_must_add_frozenbit);
170 			if (vm_crashsafe_match)
171 				transfer_relfile(&maps[mapnum], "_vm", vm_must_add_frozenbit);
172 		}
173 	}
174 }
175 
176 
177 /*
178  * transfer_relfile()
179  *
180  * Copy or link file from old cluster to new one.  If vm_must_add_frozenbit
181  * is true, visibility map forks are converted and rewritten, even in link
182  * mode.
183  */
184 static void
transfer_relfile(FileNameMap * map,const char * type_suffix,bool vm_must_add_frozenbit)185 transfer_relfile(FileNameMap *map, const char *type_suffix, bool vm_must_add_frozenbit)
186 {
187 	char		old_file[MAXPGPATH];
188 	char		new_file[MAXPGPATH];
189 	int			segno;
190 	char		extent_suffix[65];
191 	struct stat statbuf;
192 
193 	/*
194 	 * Now copy/link any related segments as well. Remember, PG breaks large
195 	 * files into 1GB segments, the first segment has no extension, subsequent
196 	 * segments are named relfilenode.1, relfilenode.2, relfilenode.3.
197 	 */
198 	for (segno = 0;; segno++)
199 	{
200 		if (segno == 0)
201 			extent_suffix[0] = '\0';
202 		else
203 			snprintf(extent_suffix, sizeof(extent_suffix), ".%d", segno);
204 
205 		snprintf(old_file, sizeof(old_file), "%s%s/%u/%u%s%s",
206 				 map->old_tablespace,
207 				 map->old_tablespace_suffix,
208 				 map->old_db_oid,
209 				 map->old_relfilenode,
210 				 type_suffix,
211 				 extent_suffix);
212 		snprintf(new_file, sizeof(new_file), "%s%s/%u/%u%s%s",
213 				 map->new_tablespace,
214 				 map->new_tablespace_suffix,
215 				 map->new_db_oid,
216 				 map->new_relfilenode,
217 				 type_suffix,
218 				 extent_suffix);
219 
220 		/* Is it an extent, fsm, or vm file? */
221 		if (type_suffix[0] != '\0' || segno != 0)
222 		{
223 			/* Did file open fail? */
224 			if (stat(old_file, &statbuf) != 0)
225 			{
226 				/* File does not exist?  That's OK, just return */
227 				if (errno == ENOENT)
228 					return;
229 				else
230 					pg_fatal("error while checking for file existence \"%s.%s\" (\"%s\" to \"%s\"): %s\n",
231 							 map->nspname, map->relname, old_file, new_file,
232 							 strerror(errno));
233 			}
234 
235 			/* If file is empty, just return */
236 			if (statbuf.st_size == 0)
237 				return;
238 		}
239 
240 		unlink(new_file);
241 
242 		/* Copying files might take some time, so give feedback. */
243 		pg_log(PG_STATUS, "%s", old_file);
244 
245 		if (vm_must_add_frozenbit && strcmp(type_suffix, "_vm") == 0)
246 		{
247 			/* Need to rewrite visibility map format */
248 			pg_log(PG_VERBOSE, "rewriting \"%s\" to \"%s\"\n",
249 				   old_file, new_file);
250 			rewriteVisibilityMap(old_file, new_file, map->nspname, map->relname);
251 		}
252 		else
253 			switch (user_opts.transfer_mode)
254 			{
255 				case TRANSFER_MODE_CLONE:
256 					pg_log(PG_VERBOSE, "cloning \"%s\" to \"%s\"\n",
257 						   old_file, new_file);
258 					cloneFile(old_file, new_file, map->nspname, map->relname);
259 					break;
260 				case TRANSFER_MODE_COPY:
261 					pg_log(PG_VERBOSE, "copying \"%s\" to \"%s\"\n",
262 						   old_file, new_file);
263 					copyFile(old_file, new_file, map->nspname, map->relname);
264 					break;
265 				case TRANSFER_MODE_LINK:
266 					pg_log(PG_VERBOSE, "linking \"%s\" to \"%s\"\n",
267 						   old_file, new_file);
268 					linkFile(old_file, new_file, map->nspname, map->relname);
269 			}
270 	}
271 }
272