2 * mdadm - manage Linux "md" devices aka RAID arrays.
4 * Copyright (C) 2001-2009 Neil Brown <neilb@suse.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * Email: <neilb@suse.de>
31 * Policy module for mdadm.
32 * A policy statement about a device lists a set of values for each
33 * of a set of names. Each value can have a metadata type as context.
36 * action - the actions that can be taken on hot-plug
37 * domain - the domain(s) that the device is part of
39 * Policy information is extracted from various sources, but
40 * particularly from a set of policy rules in mdadm.conf
43 static void pol_new(struct dev_policy
**pol
, char *name
, const char *val
,
46 struct dev_policy
*n
= xmalloc(sizeof(*n
));
47 const char *real_metadata
= NULL
;
53 /* We need to normalise the metadata name */
55 for (i
= 0; superlist
[i
] ; i
++)
56 if (strcmp(metadata
, superlist
[i
]->name
) == 0) {
57 real_metadata
= superlist
[i
]->name
;
61 if (strcmp(metadata
, "1") == 0 ||
62 strcmp(metadata
, "1.0") == 0 ||
63 strcmp(metadata
, "1.1") == 0 ||
64 strcmp(metadata
, "1.2") == 0)
65 real_metadata
= super1
.name
;
68 static const char *prev
= NULL
;
69 if (prev
!= metadata
) {
70 pr_err("metadata=%s unrecognised - ignoring rule\n",
74 real_metadata
= "unknown";
78 n
->metadata
= real_metadata
;
83 static int pol_lesseq(struct dev_policy
*a
, struct dev_policy
*b
)
87 if (a
->name
< b
->name
)
89 if (a
->name
> b
->name
)
92 cmp
= strcmp(a
->value
, b
->value
);
98 return (a
->metadata
<= b
->metadata
);
101 static void pol_sort(struct dev_policy
**pol
)
103 /* sort policy list in *pol by name/metadata/value
107 struct dev_policy
*pl
[2];
112 struct dev_policy
**plp
[2], *p
[2];
114 struct dev_policy nul
= { NULL
, NULL
, NULL
, NULL
};
115 struct dev_policy
*prev
= &nul
;
118 /* p[] are the two lists that we are merging.
119 * plp[] are the ends of the two lists we create
121 * 'curr' is which of plp[] that we are currently
123 * 'next' is which if p[] we will take the next
125 * 'prev' is that last value, which was placed in
133 /* take least of p[0] and p[1]
134 * if it is larger than prev, add to
135 * plp[curr], else swap curr then add
137 while (p
[0] || p
[1]) {
138 if (p
[next
] == NULL
||
139 (p
[1-next
] != NULL
&&
140 !(pol_lesseq(prev
, p
[1-next
])
141 ^pol_lesseq(prev
, p
[next
])
142 ^pol_lesseq(p
[next
], p
[1-next
])))
146 if (!pol_lesseq(prev
, p
[next
]))
149 *plp
[curr
] = prev
= p
[next
];
150 plp
[curr
] = &p
[next
]->next
;
151 p
[next
] = p
[next
]->next
;
155 } while (pl
[0] && pl
[1]);
162 static void pol_dedup(struct dev_policy
*pol
)
164 /* This is a sorted list - remove duplicates. */
165 while (pol
&& pol
->next
) {
166 if (pol_lesseq(pol
->next
, pol
)) {
167 struct dev_policy
*tmp
= pol
->next
;
168 pol
->next
= tmp
->next
;
176 * pol_find finds the first entry in the policy
177 * list to match name.
178 * If it returns non-NULL there is at least one
179 * value, but how many can only be found by
180 * iterating through the list.
182 struct dev_policy
*pol_find(struct dev_policy
*pol
, char *name
)
184 while (pol
&& pol
->name
< name
)
187 if (!pol
|| pol
->name
!= name
)
192 static char *disk_path(struct mdinfo
*disk
)
197 char symlink
[PATH_MAX
] = "/dev/disk/by-path/";
202 by_path
= opendir(symlink
);
204 prefix_len
= strlen(symlink
);
205 while ((ent
= readdir(by_path
)) != NULL
) {
206 if (ent
->d_type
!= DT_LNK
)
208 strncpy(symlink
+ prefix_len
,
210 sizeof(symlink
) - prefix_len
);
211 if (stat(symlink
, &stb
) < 0)
213 if ((stb
.st_mode
& S_IFMT
) != S_IFBLK
)
215 if (stb
.st_rdev
!= makedev(disk
->disk
.major
, disk
->disk
.minor
))
218 return xstrdup(ent
->d_name
);
222 /* A NULL path isn't really acceptable - use the devname.. */
223 sprintf(symlink
, "/sys/dev/block/%d:%d", disk
->disk
.major
, disk
->disk
.minor
);
224 rv
= readlink(symlink
, nm
, sizeof(nm
)-1);
228 dname
= strrchr(nm
, '/');
230 return xstrdup(dname
+ 1);
232 return xstrdup("unknown");
235 char type_part
[] = "part";
236 char type_disk
[] = "disk";
237 static char *disk_type(struct mdinfo
*disk
)
241 sprintf(buf
, "/sys/dev/block/%d:%d/partition",
242 disk
->disk
.major
, disk
->disk
.minor
);
243 if (stat(buf
, &stb
) == 0)
249 static int pol_match(struct rule
*rule
, char *path
, char *type
)
251 /* check if this rule matches on path and type */
252 int pathok
= 0; /* 0 == no path, 1 == match, -1 == no match yet */
256 if (rule
->name
== rule_path
) {
259 if (path
&& fnmatch(rule
->value
, path
, 0) == 0)
262 if (rule
->name
== rule_type
) {
265 if (type
&& strcmp(rule
->value
, type
) == 0)
270 return pathok
>= 0 && typeok
>= 0;
273 static void pol_merge(struct dev_policy
**pol
, struct rule
*rule
)
275 /* copy any name assignments from rule into pol */
277 char *metadata
= NULL
;
278 for (r
= rule
; r
; r
= r
->next
)
279 if (r
->name
== pol_metadata
)
282 for (r
= rule
; r
; r
= r
->next
)
283 if (r
->name
== pol_act
||
284 r
->name
== pol_domain
||
286 pol_new(pol
, r
->name
, r
->value
, metadata
);
289 static int path_has_part(char *path
, char **part
)
291 /* check if path ends with "-partNN" and
292 * if it does, place a pointer to "-pathNN"
299 while (l
> 1 && isdigit(path
[l
-1]))
301 if (l
< 5 || strncmp(path
+l
-5, "-part", 5) != 0)
307 static void pol_merge_part(struct dev_policy
**pol
, struct rule
*rule
, char *part
)
309 /* copy any name assignments from rule into pol, appending
310 * -part to any domain. The string with -part appended is
311 * stored with the rule so it has a lifetime to match
315 char *metadata
= NULL
;
316 for (r
= rule
; r
; r
= r
->next
)
317 if (r
->name
== pol_metadata
)
320 for (r
= rule
; r
; r
= r
->next
) {
321 if (r
->name
== pol_act
)
322 pol_new(pol
, r
->name
, r
->value
, metadata
);
323 else if (r
->name
== pol_domain
) {
328 len
= strlen(r
->value
);
329 for (dom
= dl_next(r
->dups
); dom
!= r
->dups
;
331 if (strcmp(dom
+len
+1, part
)== 0)
333 if (dom
== r
->dups
) {
334 char *newdom
= dl_strndup(
335 r
->value
, len
+ 1 + strlen(part
));
336 strcat(strcat(newdom
, "-"), part
);
337 dl_add(r
->dups
, newdom
);
340 pol_new(pol
, r
->name
, dom
, metadata
);
345 static struct pol_rule
*config_rules
= NULL
;
346 static struct pol_rule
**config_rules_end
= NULL
;
347 static int config_rules_has_path
= 0;
350 * most policy comes from a set policy rules that are
351 * read from the config file.
352 * path_policy() gathers policy information for the
353 * disk described in the given a 'path' and a 'type'.
355 struct dev_policy
*path_policy(char *path
, char *type
)
357 struct pol_rule
*rules
;
358 struct dev_policy
*pol
= NULL
;
361 rules
= config_rules
;
365 if (rules
->type
== rule_policy
)
366 if (pol_match(rules
->rule
, path
, type
))
367 pol_merge(&pol
, rules
->rule
);
368 if (rules
->type
== rule_part
&& strcmp(type
, type_part
) == 0)
369 if (path_has_part(path
, &part
)) {
371 if (pol_match(rules
->rule
, path
, type_disk
))
372 pol_merge_part(&pol
, rules
->rule
, part
+1);
378 /* Now add any metadata-specific internal knowledge
381 for (i
=0; path
&& superlist
[i
]; i
++)
382 if (superlist
[i
]->get_disk_controller_domain
) {
384 superlist
[i
]->get_disk_controller_domain(path
);
386 pol_new(&pol
, pol_domain
, d
, superlist
[i
]->name
);
394 void pol_add(struct dev_policy
**pol
,
395 char *name
, char *val
,
398 pol_new(pol
, name
, val
, metadata
);
404 * disk_policy() gathers policy information for the
405 * disk described in the given mdinfo (disk.{major,minor}).
407 struct dev_policy
*disk_policy(struct mdinfo
*disk
)
410 char *type
= disk_type(disk
);
411 struct dev_policy
*pol
= NULL
;
413 if (config_rules_has_path
)
414 path
= disk_path(disk
);
416 pol
= path_policy(path
, type
);
422 struct dev_policy
*devid_policy(int dev
)
425 disk
.disk
.major
= major(dev
);
426 disk
.disk
.minor
= minor(dev
);
427 return disk_policy(&disk
);
431 * process policy rules read from config file.
434 char rule_path
[] = "path";
435 char rule_type
[] = "type";
437 char rule_policy
[] = "policy";
438 char rule_part
[] = "part-policy";
440 char pol_metadata
[] = "metadata";
441 char pol_act
[] = "action";
442 char pol_domain
[] = "domain";
443 char pol_auto
[] = "auto";
445 static int try_rule(char *w
, char *name
, struct rule
**rp
)
448 int len
= strlen(name
);
449 if (strncmp(w
, name
, len
) != 0 ||
452 r
= xmalloc(sizeof(*r
));
455 r
->value
= xstrdup(w
+len
+1);
461 void policyline(char *line
, char *type
)
466 if (config_rules_end
== NULL
)
467 config_rules_end
= &config_rules
;
469 pr
= xmalloc(sizeof(*pr
));
472 for (w
= dl_next(line
); w
!= line
; w
= dl_next(w
)) {
473 if (try_rule(w
, rule_path
, &pr
->rule
))
474 config_rules_has_path
= 1;
475 else if (! try_rule(w
, rule_type
, &pr
->rule
) &&
476 ! try_rule(w
, pol_metadata
, &pr
->rule
) &&
477 ! try_rule(w
, pol_act
, &pr
->rule
) &&
478 ! try_rule(w
, pol_domain
, &pr
->rule
) &&
479 ! try_rule(w
, pol_auto
, &pr
->rule
))
480 pr_err("policy rule %s unrecognised and ignored\n",
483 pr
->next
= config_rules
;
487 void policy_add(char *type
, ...)
493 pr
= xmalloc(sizeof(*pr
));
498 while ((name
= va_arg(ap
, char*)) != NULL
) {
501 val
= va_arg(ap
, char*);
502 r
= xmalloc(sizeof(*r
));
505 r
->value
= xstrdup(val
);
509 pr
->next
= config_rules
;
514 void policy_free(void)
516 while (config_rules
) {
517 struct pol_rule
*pr
= config_rules
;
520 config_rules
= config_rules
->next
;
522 for (r
= pr
->rule
; r
; ) {
523 struct rule
*next
= r
->next
;
532 config_rules_end
= NULL
;
533 config_rules_has_path
= 0;
536 void dev_policy_free(struct dev_policy
*p
)
538 struct dev_policy
*t
;
546 static enum policy_action
map_act(const char *act
)
548 if (strcmp(act
, "include") == 0)
550 if (strcmp(act
, "re-add") == 0)
552 if (strcmp(act
, "spare") == 0)
554 if (strcmp(act
, "spare-same-slot") == 0)
555 return act_spare_same_slot
;
556 if (strcmp(act
, "force-spare") == 0)
557 return act_force_spare
;
561 static enum policy_action
policy_action(struct dev_policy
*plist
, const char *metadata
)
563 enum policy_action rv
= act_default
;
564 struct dev_policy
*p
;
566 plist
= pol_find(plist
, pol_act
);
567 pol_for_each(p
, plist
, metadata
) {
568 enum policy_action a
= map_act(p
->value
);
575 int policy_action_allows(struct dev_policy
*plist
, const char *metadata
, enum policy_action want
)
577 enum policy_action act
= policy_action(plist
, metadata
);
581 return (act
>= want
);
584 int disk_action_allows(struct mdinfo
*disk
, const char *metadata
, enum policy_action want
)
586 struct dev_policy
*pol
= disk_policy(disk
);
587 int rv
= policy_action_allows(pol
, metadata
, want
);
589 dev_policy_free(pol
);
594 * Any device can have a list of domains asserted by different policy
596 * An array also has a list of domains comprising all the domains of
597 * all the devices in an array.
598 * Where an array has a spare-group, that becomes an addition domain for
599 * every device in the array and thus for the array.
601 * We keep the list of domains in a sorted linked list
602 * As dev policies are already sorted, this is fairly easy to manage.
605 static struct domainlist
**domain_merge_one(struct domainlist
**domp
,
608 /* merge a domain name into a sorted list and return the
609 * location of the insertion or match
611 struct domainlist
*dom
= *domp
;
613 while (dom
&& strcmp(dom
->dom
, domain
) < 0) {
617 if (dom
== NULL
|| strcmp(dom
->dom
, domain
) != 0) {
618 dom
= xmalloc(sizeof(*dom
));
627 void dump_policy(struct dev_policy
*policy
)
630 dprintf("policy: %p name: %s value: %s metadata: %s\n",
635 policy
= policy
->next
;
640 void domain_merge(struct domainlist
**domp
, struct dev_policy
*pollist
,
641 const char *metadata
)
643 /* Add to 'domp' all the domains in pol that apply to 'metadata'
644 * which are not already in domp
646 struct dev_policy
*pol
;
647 pollist
= pol_find(pollist
, pol_domain
);
648 pol_for_each(pol
, pollist
, metadata
)
649 domain_merge_one(domp
, pol
->value
);
652 int domain_test(struct domainlist
*dom
, struct dev_policy
*pol
,
653 const char *metadata
)
655 /* Check that all domains in pol (for metadata) are also in
656 * dom. Both lists are sorted.
657 * If pol has no domains, we don't really know about this device
658 * so we allow caller to choose:
660 * 0: has domains, not all match
661 * 1: has domains, all match
664 struct dev_policy
*p
;
666 pol
= pol_find(pol
, pol_domain
);
667 pol_for_each(p
, pol
, metadata
) {
669 while (dom
&& strcmp(dom
->dom
, p
->value
) < 0)
671 if (!dom
|| strcmp(dom
->dom
, p
->value
) != 0)
677 void domainlist_add_dev(struct domainlist
**dom
, int devid
, const char *metadata
)
679 struct dev_policy
*pol
= devid_policy(devid
);
680 domain_merge(dom
, pol
, metadata
);
681 dev_policy_free(pol
);
684 struct domainlist
*domain_from_array(struct mdinfo
*mdi
, const char *metadata
)
686 struct domainlist
*domlist
= NULL
;
690 for (mdi
= mdi
->devs
; mdi
; mdi
= mdi
->next
)
691 domainlist_add_dev(&domlist
, makedev(mdi
->disk
.major
,
698 void domain_add(struct domainlist
**domp
, char *domain
)
700 domain_merge_one(domp
, domain
);
703 void domain_free(struct domainlist
*dl
)
706 struct domainlist
*head
= dl
;
714 * Some policy decisions are guided by knowledge of which
715 * array previously owned the device at a given physical location (path).
716 * When removing a device from an array we might record the array against
717 * the path, and when finding a new device, we might look for which
718 * array previously used that path.
720 * The 'array' is described by a map_ent, and the path by a the disk in an
721 * mdinfo, or a string.
724 void policy_save_path(char *id_path
, struct map_ent
*array
)
729 if (mkdir(FAILED_SLOTS_DIR
, S_IRWXU
) < 0 && errno
!= EEXIST
) {
730 pr_err("can't create file to save path to old disk: %s\n", strerror(errno
));
734 snprintf(path
, PATH_MAX
, FAILED_SLOTS_DIR
"/%s", id_path
);
735 f
= fopen(path
, "w");
737 pr_err("can't create file to save path to old disk: %s\n",
742 if (fprintf(f
, "%s %08x:%08x:%08x:%08x\n",
744 array
->uuid
[0], array
->uuid
[1],
745 array
->uuid
[2], array
->uuid
[3]) <= 0)
746 pr_err("Failed to write to <id_path> cookie\n");
751 int policy_check_path(struct mdinfo
*disk
, struct map_ent
*array
)
755 char *id_path
= disk_path(disk
);
761 snprintf(path
, PATH_MAX
, FAILED_SLOTS_DIR
"/%s", id_path
);
762 f
= fopen(path
, "r");
768 rv
= fscanf(f
, " %s %x:%x:%x:%x\n",
779 /* invocation of udev rule file */
780 char udev_template_start
[] =
781 "# do not edit this file, it is automatically generated by mdadm\n"
784 /* find rule named rule_type and return its value */
785 char *find_rule(struct rule
*rule
, char *rule_type
)
788 if (rule
->name
== rule_type
)
796 #define UDEV_RULE_FORMAT \
797 "ACTION==\"add\", SUBSYSTEM==\"block\", " \
798 "ENV{DEVTYPE}==\"%s\", ENV{ID_PATH}==\"%s\", " \
799 "RUN+=\"" BINDIR "/mdadm --incremental $env{DEVNAME}\"\n"
801 #define UDEV_RULE_FORMAT_NOTYPE \
802 "ACTION==\"add\", SUBSYSTEM==\"block\", " \
803 "ENV{ID_PATH}==\"%s\", " \
804 "RUN+=\"" BINDIR "/mdadm --incremental $env{DEVNAME}\"\n"
806 /* Write rule in the rule file. Use format from UDEV_RULE_FORMAT */
807 int write_rule(struct rule
*rule
, int fd
, int force_part
)
810 char *pth
= find_rule(rule
, rule_path
);
811 char *typ
= find_rule(rule
, rule_type
);
818 snprintf(line
, sizeof(line
) - 1, UDEV_RULE_FORMAT
, typ
, pth
);
820 snprintf(line
, sizeof(line
) - 1, UDEV_RULE_FORMAT_NOTYPE
, pth
);
821 return write(fd
, line
, strlen(line
)) == (int)strlen(line
);
824 /* Generate single entry in udev rule basing on POLICY line found in config
825 * file. Take only those with paths, only first occurrence if paths are equal
826 * and if actions supports handling of spares (>=act_spare_same_slot)
828 int generate_entries(int fd
)
830 struct pol_rule
*loop
, *dup
;
831 char *loop_value
, *dup_value
;
834 for (loop
= config_rules
; loop
; loop
= loop
->next
) {
835 if (loop
->type
!= rule_policy
&& loop
->type
!= rule_part
)
839 /* only policies with paths and with actions supporting
840 * bare disks are considered */
841 loop_value
= find_rule(loop
->rule
, pol_act
);
842 if (!loop_value
|| map_act(loop_value
) < act_spare_same_slot
)
844 loop_value
= find_rule(loop
->rule
, rule_path
);
847 for (dup
= config_rules
; dup
!= loop
; dup
= dup
->next
) {
848 if (dup
->type
!= rule_policy
&& loop
->type
!= rule_part
)
850 dup_value
= find_rule(dup
->rule
, pol_act
);
851 if (!dup_value
|| map_act(dup_value
) < act_spare_same_slot
)
853 dup_value
= find_rule(dup
->rule
, rule_path
);
856 if (strcmp(loop_value
, dup_value
) == 0) {
862 /* not a dup or first occurrence */
864 if (!write_rule(loop
->rule
, fd
, loop
->type
== rule_part
) )
870 /* Write_rules routine creates dynamic udev rules used to handle
871 * hot-plug events for bare devices (and making them spares)
873 int Write_rules(char *rule_name
)
876 char udev_rule_file
[PATH_MAX
];
879 strncpy(udev_rule_file
, rule_name
, sizeof(udev_rule_file
) - 6);
880 udev_rule_file
[sizeof(udev_rule_file
) - 6] = '\0';
881 strcat(udev_rule_file
, ".temp");
882 fd
= creat(udev_rule_file
,
883 S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IROTH
);
889 /* write static invocation */
890 if (write(fd
, udev_template_start
,
891 sizeof(udev_template_start
) - 1)
892 != (int)sizeof(udev_template_start
)-1)
895 /* iterate, if none created or error occurred, remove file */
896 if (generate_entries(fd
) < 0)
902 rename(udev_rule_file
, rule_name
);
908 unlink(udev_rule_file
);