librazor/root.c
author J. Ali Harlow <ali@juiblex.co.uk>
Wed Apr 22 15:09:17 2009 +0100 (2009-04-22)
changeset 359 c9c90315ea24
parent 345 edd9b0fa63ca
child 373 fda83d91e600
permissions -rw-r--r--
Add support for named roots so that we can understand MS-Windows paths
such as c:/windows. Without this, the user always has to ensure they
are on the correct drive before running razor.
     1 /*
     2  * Copyright (C) 2008  Kristian Høgsberg <krh@redhat.com>
     3  * Copyright (C) 2008  Red Hat, Inc
     4  * Copyright (C) 2009  J. Ali Harlow <ali@juiblex.co.uk>
     5  *
     6  * This program is free software; you can redistribute it and/or modify
     7  * it under the terms of the GNU General Public License as published by
     8  * the Free Software Foundation; either version 2 of the License, or
     9  * (at your option) any later version.
    10  *
    11  * This program is distributed in the hope that it will be useful,
    12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    14  * GNU General Public License for more details.
    15  *
    16  * You should have received a copy of the GNU General Public License along
    17  * with this program; if not, write to the Free Software Foundation, Inc.,
    18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
    19  */
    20 
    21 #include "config.h"
    22 
    23 #include <stdlib.h>
    24 #include <stdint.h>
    25 #include <stdio.h>
    26 #include <string.h>
    27 #include <sys/stat.h>
    28 #include <dirent.h>
    29 #include <unistd.h>
    30 #include <fcntl.h>
    31 #include <limits.h>
    32 #include <assert.h>
    33 #ifdef MSWIN_API
    34 #include <shlobj.h>
    35 #endif
    36 
    37 #include "razor.h"
    38 #include "razor-internal.h"
    39 
    40 #ifndef O_BINARY
    41 #define O_BINARY	0
    42 #endif
    43 
    44 static const char system_repo_filename[] = "system.rzdb";
    45 static const char system_repo_details_filename[] = "system-details.rzdb";
    46 static const char system_repo_files_filename[] = "system-files.rzdb";
    47 
    48 static const char next_repo_filename[] = "system-next.rzdb";
    49 #ifdef MSWIN_API
    50 #define RAZOR_ROOT_PATH	NULL
    51 #else
    52 #define RAZOR_ROOT_PATH	"/var/lib/razor"
    53 #endif
    54 static const char *razor_root_path = RAZOR_ROOT_PATH;
    55 
    56 struct razor_root {
    57 	struct razor_set *system;
    58 	struct razor_set *next;
    59 	int fd;
    60 	char root[PATH_MAX];
    61 	char path[PATH_MAX];
    62 	char new_path[PATH_MAX];
    63 };
    64 
    65 static void
    66 razor_root_init(void)
    67 {
    68 #ifdef MSWIN_API
    69 	static char root_path[MAX_PATH];
    70 	if (!razor_root_path) {
    71 		SHGetFolderPath(NULL,
    72 			CSIDL_COMMON_APPDATA | CSIDL_FLAG_DONT_VERIFY, NULL, 0,
    73 			root_path);
    74 		strcat(root_path, "\\Razor");
    75 		razor_root_path = root_path;
    76 	}
    77 #endif
    78 }
    79 
    80 RAZOR_EXPORT int
    81 razor_root_create(const char *root)
    82 {
    83 	struct stat buf;
    84 	struct razor_set *set;
    85 	char path[PATH_MAX], details_path[PATH_MAX], files_path[PATH_MAX];
    86 
    87 	assert (root != NULL);
    88 
    89 	razor_root_init();
    90 	if (root[0] == '\0') {
    91 		/* root is file system root */
    92 	} else if (stat(root, &buf) < 0) {
    93 		if (mkdir(root, 0777) < 0) {
    94 			fprintf(stderr,
    95 				"could not create install root \"%s\"\n",
    96 				root);
    97 			return -1;
    98 		}
    99 		fprintf(stderr, "created install root \"%s\"\n", root);
   100 	} else if (!S_ISDIR(buf.st_mode)) {
   101 		fprintf(stderr,
   102 			"install root \"%s\" exists, but is not a directory\n",
   103 			root);
   104 		return -1;
   105 	}
   106 
   107 	snprintf(path, sizeof path, "%s/%s",
   108 		 razor_root_path, system_repo_filename);
   109 	if (razor_create_dir(root, path) < 0) {
   110 		fprintf(stderr, "could not create %s%s\n",
   111 			root, razor_root_path);
   112 		return -1;
   113 	}
   114 
   115 	set = razor_set_create();
   116 	snprintf(path, sizeof path, "%s%s/%s",
   117 		 root, razor_root_path, system_repo_filename);
   118 	snprintf(details_path, sizeof details_path, "%s%s/%s",
   119 		 root, razor_root_path, system_repo_details_filename);
   120 	snprintf(files_path, sizeof files_path, "%s%s/%s",
   121 		 root, razor_root_path, system_repo_files_filename);
   122 	if (stat(path, &buf) == 0) {
   123 		fprintf(stderr,
   124 			"a razor install root is already initialized\n");
   125 		return -1;
   126 	}
   127 	if (razor_set_write(set, path, RAZOR_REPO_FILE_MAIN) < 0 ||
   128 	    razor_set_write(set, details_path, RAZOR_REPO_FILE_DETAILS) < 0 ||
   129 	    razor_set_write(set, files_path, RAZOR_REPO_FILE_FILES) < 0 ) {
   130 		fprintf(stderr, "could not write initial package set\n");
   131 		return -1;
   132 	}
   133 	razor_set_destroy(set);
   134 
   135 	return 0;
   136 }
   137 
   138 RAZOR_EXPORT struct razor_root *
   139 razor_root_open(const char *root)
   140 {
   141 	struct razor_root *image;
   142 	char details_path[PATH_MAX], files_path[PATH_MAX];
   143 
   144 	assert (root != NULL);
   145 
   146 	razor_root_init();
   147 	image = malloc(sizeof *image);
   148 	if (image == NULL)
   149 		return NULL;
   150 
   151 	/* Create the new next repo file up front to ensure exclusive
   152 	 * access. */
   153 	snprintf(image->new_path, sizeof image->new_path,
   154 		 "%s%s/%s", root, razor_root_path, next_repo_filename);
   155 	image->fd = open(image->new_path,
   156 			 O_CREAT | O_WRONLY | O_TRUNC | O_EXCL | O_BINARY,
   157 			 0666);
   158 	if (image->fd < 0) {
   159 		fprintf(stderr, "failed to get lock file, "
   160 			"maybe previous operation crashed?\n");
   161 
   162 		/* FIXME: Use fcntl advisory locking on the system
   163 		 * package set file to figure out whether previous
   164 		 * operation crashed or is still in progress. */
   165 
   166 		free(image);
   167 		return NULL;
   168 	}
   169 
   170 	snprintf(image->path, sizeof image->path,
   171 		 "%s%s/%s", root, razor_root_path, system_repo_filename);
   172 	snprintf(details_path, sizeof details_path,
   173 		 "%s%s/%s", root, razor_root_path, system_repo_details_filename);
   174 	snprintf(files_path, sizeof files_path,
   175 		 "%s%s/%s", root, razor_root_path, system_repo_files_filename);
   176 
   177 	/* FIXME: We store the root path to make the hack in
   178 	 * razor_root_update() work.  Need to get rid of this. */
   179 	strcpy(image->root, root);
   180 
   181 	image->system = razor_set_open(image->path);
   182 	if (image->system == NULL ||
   183 	    razor_set_open_details(image->system, details_path) ||
   184 	    razor_set_open_files(image->system, files_path)) {
   185 		unlink(image->new_path);
   186 		close(image->fd);
   187 		free(image);
   188 		return NULL;
   189 	}
   190 
   191 	return image;
   192 }
   193 
   194 RAZOR_EXPORT struct razor_set *
   195 razor_root_open_read_only(const char *root)
   196 {
   197 	char path[PATH_MAX], details_path[PATH_MAX], files_path[PATH_MAX];
   198 	struct razor_set *set;
   199 
   200 	assert (root != NULL);
   201 
   202 	razor_root_init();
   203 	snprintf(path, sizeof path, "%s%s/%s",
   204 		 root, razor_root_path, system_repo_filename);
   205 	snprintf(details_path, sizeof details_path,
   206 		 "%s%s/%s", root, razor_root_path, system_repo_details_filename);
   207 	snprintf(files_path, sizeof files_path,
   208 		 "%s%s/%s", root, razor_root_path, system_repo_files_filename);
   209 
   210 
   211 	set = razor_set_open(path);
   212 	if (set == NULL)
   213 		return NULL;
   214 
   215 	if (razor_set_open_details(set, details_path) ||
   216 	    razor_set_open_files(set, files_path)) {
   217 		razor_set_destroy(set);
   218 		return NULL;
   219 	}
   220 
   221 	return set;
   222 }
   223 
   224 RAZOR_EXPORT struct razor_set *
   225 razor_root_get_system_set(struct razor_root *root)
   226 {
   227 	assert (root != NULL);
   228 
   229 	return root->system;
   230 }
   231 
   232 RAZOR_EXPORT int
   233 razor_root_close(struct razor_root *root)
   234 {
   235 	assert (root != NULL);
   236 
   237 	razor_set_destroy(root->system);
   238 	close(root->fd);
   239 	unlink(root->new_path);
   240 	free(root);
   241 
   242 	return 0;
   243 }
   244 
   245 RAZOR_EXPORT void
   246 razor_root_update(struct razor_root *root, struct razor_set *next)
   247 {
   248 	char path[PATH_MAX];
   249 
   250 	assert (root != NULL);
   251 	assert (next != NULL);
   252 
   253 	razor_root_init();
   254 	razor_set_write_to_fd(next, root->fd, RAZOR_REPO_FILE_MAIN);
   255 	root->next = next;
   256 
   257 	/* FIXME: This is a pretty bad hack that just overwrites the
   258 	 * system details and files rzdb files before the transaction
   259 	 * succeeds.  We need to fix this by merging the separate
   260 	 * details and files rzdb files back into the main rzdb
   261 	 * file. */
   262 	snprintf(path, sizeof path,
   263 		 "%s%s/%s", root->root, razor_root_path, system_repo_details_filename);
   264 	razor_set_write(next, path, RAZOR_REPO_FILE_DETAILS);
   265 	snprintf(path, sizeof path,
   266 		 "%s%s/%s", root->root, razor_root_path, system_repo_files_filename);
   267 	razor_set_write(next, path, RAZOR_REPO_FILE_FILES);
   268 
   269 	/* Sync the new repo file so the new package set is on disk
   270 	 * before we start upgrading. */
   271 	fsync(root->fd);
   272 	printf("wrote %s\n", root->new_path);
   273 }
   274 
   275 RAZOR_EXPORT int
   276 razor_root_commit(struct razor_root *root)
   277 {
   278 	int retval;
   279 	assert (root != NULL);
   280 
   281 	/* Make it so. */
   282 	close(root->fd);
   283 #ifdef MSWIN_API
   284 	/* Rename is not atomic under MS-Windows */
   285 	remove(root->path);
   286 #endif
   287 	retval = rename(root->new_path, root->path);
   288 	if (retval)
   289 		perror(root->path);
   290 	else
   291 		printf("renamed %s to %s\n", root->new_path, root->path);
   292 	razor_set_destroy(root->system);
   293 	free(root);
   294 
   295 	return retval;
   296 }