]>
git.ipfire.org Git - thirdparty/e2fsprogs.git/blob - lib/blkid/save.c
762ffefd7313ce11b4f8e696b976c930ba5bcd53
2 * save.c - write the cache struct to disk
4 * Copyright (C) 2001 by Andreas Dilger
5 * Copyright (C) 2003 Theodore Ts'o
8 * This file may be redistributed under the terms of the
9 * GNU Lesser General Public License.
18 #include <sys/types.h>
19 #ifdef HAVE_SYS_STAT_H
22 #ifdef HAVE_SYS_MKDEV_H
23 #include <sys/mkdev.h>
30 static int save_dev(blkid_dev dev
, FILE *file
)
34 if (!dev
|| dev
->bid_name
[0] != '/')
38 printf("device %s, type %s\n", dev
->bid_name
, dev
->bid_type
?
39 dev
->bid_type
: "(null)"));
42 "<device DEVNO=\"0x%04lx\" TIME=\"%ld\"",
43 (unsigned long) dev
->bid_devno
, (long) dev
->bid_time
);
45 fprintf(file
, " PRI=\"%d\"", dev
->bid_pri
);
46 list_for_each(p
, &dev
->bid_tags
) {
47 blkid_tag tag
= list_entry(p
, struct blkid_struct_tag
, bit_tags
);
48 fprintf(file
, " %s=\"%s\"", tag
->bit_name
,tag
->bit_val
);
50 fprintf(file
, ">%s</device>\n", dev
->bid_name
);
56 * Write out the cache struct to the cache file on disk.
58 int blkid_flush_cache(blkid_cache cache
)
62 const char *opened
= NULL
;
69 return -BLKID_ERR_PARAM
;
71 if (list_empty(&cache
->bic_devs
) ||
72 !(cache
->bic_flags
& BLKID_BIC_FL_CHANGED
)) {
73 DBG(DEBUG_SAVE
, printf("skipping cache file write\n"));
77 filename
= cache
->bic_filename
? cache
->bic_filename
: BLKID_CACHE_FILE
;
79 /* If we can't write to the cache file, then don't even try */
80 if (((ret
= stat(filename
, &st
)) < 0 && errno
!= ENOENT
) ||
81 (ret
== 0 && access(filename
, W_OK
) < 0)) {
83 printf("can't write to cache file %s\n", filename
));
88 * Try and create a temporary file in the same directory so
89 * that in case of error we don't overwrite the cache file.
90 * If the cache file doesn't yet exist, it isn't a regular
91 * file (e.g. /dev/null or a socket), or we couldn't create
92 * a temporary file then we open it directly.
94 if (ret
== 0 && S_ISREG(st
.st_mode
)) {
95 tmp
= malloc(strlen(filename
) + 8);
97 mode_t save_umask
= umask(022);
98 sprintf(tmp
, "%s-XXXXXX", filename
);
102 file
= fdopen(fd
, "w");
110 file
= fopen(filename
, "w");
115 printf("writing cache file %s (really %s)\n",
123 list_for_each(p
, &cache
->bic_devs
) {
124 blkid_dev dev
= list_entry(p
, struct blkid_struct_dev
, bid_devs
);
127 if ((ret
= save_dev(dev
, file
)) < 0)
132 cache
->bic_flags
&= ~BLKID_BIC_FL_CHANGED
;
137 if (opened
!= filename
) {
139 (void) unlink(opened
);
141 printf("unlinked temp cache %s\n", opened
));
145 backup
= malloc(strlen(filename
) + 5);
147 sprintf(backup
, "%s.old", filename
);
149 (void) link(filename
, backup
);
152 if (rename(opened
, filename
) < 0)
153 (void) unlink(opened
);
155 printf("moved temp cache %s\n", opened
));
165 int main(int argc
, char **argv
)
167 blkid_cache cache
= NULL
;
170 blkid_debug_mask
= DEBUG_ALL
;
172 fprintf(stderr
, "Usage: %s [filename]\n"
173 "Test loading/saving a cache (filename)\n", argv
[0]);
177 if ((ret
= blkid_get_cache(&cache
, "/dev/null")) != 0) {
178 fprintf(stderr
, "%s: error creating cache (%d)\n",
182 if ((ret
= blkid_probe_all(cache
)) < 0) {
183 fprintf(stderr
, "error (%d) probing devices\n", ret
);
186 cache
->bic_filename
= blkid_strdup(argv
[1]);
188 if ((ret
= blkid_flush_cache(cache
)) < 0) {
189 fprintf(stderr
, "error (%d) saving cache\n", ret
);
193 blkid_put_cache(cache
);