[thirdparty/mdadm.git] / lib.c

/*
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2011  Neil Brown <neilb@suse.de>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *    Author: Neil Brown
 *    Email: <neilb@suse.de>
 */

#include	"mdadm.h"
#include	<ctype.h>

/* This fill contains various 'library' style function.  They
 * have no dependency on anything outside this file.
 */

int get_mdp_major(void)
{
static int mdp_major = -1;
	FILE *fl;
	char *w;
	int have_block = 0;
	int have_devices = 0;
	int last_num = -1;

	if (mdp_major != -1)
		return mdp_major;
	fl = fopen("/proc/devices", "r");
	if (!fl)
		return -1;
	while ((w = conf_word(fl, 1))) {
		if (have_block && strcmp(w, "devices:")==0)
			have_devices = 1;
		have_block =  (strcmp(w, "Block")==0);
		if (isdigit(w[0]))
			last_num = atoi(w);
		if (have_devices && strcmp(w, "mdp")==0)
			mdp_major = last_num;
		free(w);
	}
	fclose(fl);
	return mdp_major;
}

char *devid2devnm(int devid)
{
	char path[30];
	char link[200];
	static char devnm[32];
	char *cp, *ep;
	int n;

	/* Might be an extended-minor partition or a
	 * named md device. Look at the
	 * /sys/dev/block/%d:%d link which must look like
	 *    ../../block/mdXXX/mdXXXpYY
	 * or
	 *    ...../block/md_FOO
	 */
	sprintf(path, "/sys/dev/block/%d:%d", major(devid),
		minor(devid));
	n = readlink(path, link, sizeof(link)-1);
	if (n > 0) {
		link[n] = 0;
		cp = strstr(link, "/block/");
		if (cp) {
			cp += 7;
			ep = strchr(cp, '/');
			if (ep)
				*ep = 0;
			strcpy(devnm, cp);
			return devnm;
		}
	}
	if (major(devid) == MD_MAJOR)
		sprintf(devnm,"md%d", minor(devid));
	else if (major(devid) == (unsigned)get_mdp_major())
		sprintf(devnm,"md_d%d",
			(minor(devid)>>MdpMinorShift));
	else
		return NULL;
	return devnm;
}

char *stat2devnm(struct stat *st)
{
	if ((S_IFMT & st->st_mode) != S_IFBLK)
		return NULL;
	return devid2devnm(st->st_rdev);
}

char *fd2devnm(int fd)
{
	struct stat stb;
	if (fstat(fd, &stb) == 0)
		return stat2devnm(&stb);
	return NULL;
}


/*
 * convert a major/minor pair for a block device into a name in /dev, if possible.
 * On the first call, walk /dev collecting name.
 * Put them in a simple linked listfor now.
 */
struct devmap {
	int major, minor;
	char *name;
	struct devmap *next;
} *devlist = NULL;
int devlist_ready = 0;

int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
{
	struct stat st;

	if (S_ISLNK(stb->st_mode)) {
		if (stat(name, &st) != 0)
			return 0;
		stb = &st;
	}

	if ((stb->st_mode&S_IFMT)== S_IFBLK) {
		char *n = xstrdup(name);
		struct devmap *dm = xmalloc(sizeof(*dm));
		if (strncmp(n, "/dev/./", 7)==0)
			strcpy(n+4, name+6);
		if (dm) {
			dm->major = major(stb->st_rdev);
			dm->minor = minor(stb->st_rdev);
			dm->name = n;
			dm->next = devlist;
			devlist = dm;
		}
	}
	return 0;
}

#ifndef HAVE_NFTW
#ifdef HAVE_FTW
int add_dev_1(const char *name, const struct stat *stb, int flag)
{
	return add_dev(name, stb, flag, NULL);
}
int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
{
	return ftw(path, add_dev_1, nopenfd);
}
#else
int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
{
	return 0;
}
#endif /* HAVE_FTW */
#endif /* HAVE_NFTW */

/*
 * Find a block device with the right major/minor number.
 * If we find multiple names, choose the shortest.
 * If we find a name in /dev/md/, we prefer that.
 * This applies only to names for MD devices.
 * If 'prefer' is set (normally to e.g. /by-path/)
 * then we prefer a name which contains that string.
 */
char *map_dev_preferred(int major, int minor, int create,
			char *prefer)
{
	struct devmap *p;
	char *regular = NULL, *preferred=NULL;
	int did_check = 0;

	if (major == 0 && minor == 0)
			return NULL;

 retry:
	if (!devlist_ready) {
		char *dev = "/dev";
		struct stat stb;
		while(devlist) {
			struct devmap *d = devlist;
			devlist = d->next;
			free(d->name);
			free(d);
		}
		if (lstat(dev, &stb)==0 &&
		    S_ISLNK(stb.st_mode))
			dev = "/dev/.";
		nftw(dev, add_dev, 10, FTW_PHYS);
		devlist_ready=1;
		did_check = 1;
	}

	for (p=devlist; p; p=p->next)
		if (p->major == major &&
		    p->minor == minor) {
			if (strncmp(p->name, "/dev/md/",8) == 0
			    || (prefer && strstr(p->name, prefer))) {
				if (preferred == NULL ||
				    strlen(p->name) < strlen(preferred))
					preferred = p->name;
			} else {
				if (regular == NULL ||
				    strlen(p->name) < strlen(regular))
					regular = p->name;
			}
		}
	if (!regular && !preferred && !did_check) {
		devlist_ready = 0;
		goto retry;
	}
	if (create && !regular && !preferred) {
		static char buf[30];
		snprintf(buf, sizeof(buf), "%d:%d", major, minor);
		regular = buf;
	}

	return preferred ? preferred : regular;
}


/* conf_word gets one word from the conf file.
 * if "allow_key", then accept words at the start of a line,
 * otherwise stop when such a word is found.
 * We assume that the file pointer is at the end of a word, so the
 * next character is a space, or a newline.  If not, it is the start of a line.
 */

char *conf_word(FILE *file, int allow_key)
{
	int wsize = 100;
	int len = 0;
	int c;
	int quote;
	int wordfound = 0;
	char *word = xmalloc(wsize);

	while (wordfound==0) {
		/* at the end of a word.. */
		c = getc(file);
		if (c == '#')
			while (c != EOF && c != '\n')
				c = getc(file);
		if (c == EOF) break;
		if (c == '\n') continue;

		if (c != ' ' && c != '\t' && ! allow_key) {
			ungetc(c, file);
			break;
		}
		/* looks like it is safe to get a word here, if there is one */
		quote = 0;
		/* first, skip any spaces */
		while (c == ' ' || c == '\t')
			c = getc(file);
		if (c != EOF && c != '\n' && c != '#') {
			/* we really have a character of a word, so start saving it */
			while (c != EOF && c != '\n' && (quote || (c!=' ' && c != '\t'))) {
				wordfound = 1;
				if (quote && c == quote) quote = 0;
				else if (quote == 0 && (c == '\'' || c == '"'))
					quote = c;
				else {
					if (len == wsize-1) {
						wsize += 100;
						word = xrealloc(word, wsize);
					}
					word[len++] = c;
				}
				c = getc(file);
				/* Hack for broken kernels (2.6.14-.24) that put
				 *        "active(auto-read-only)"
				 * in /proc/mdstat instead of
				 *        "active (auto-read-only)"
				 */
				if (c == '(' && len >= 6
				    && strncmp(word+len-6, "active", 6) == 0)
					c = ' ';
			}
		}
		if (c != EOF) ungetc(c, file);
	}
	word[len] = 0;

	/* Further HACK for broken kernels.. 2.6.14-2.6.24 */
	if (strcmp(word, "auto-read-only)") == 0)
		strcpy(word, "(auto-read-only)");

/*    printf("word is <%s>\n", word); */
	if (!wordfound) {
		free(word);
		word = NULL;
	}
	return word;
}

void print_quoted(char *str)
{
	/* Printf the string with surrounding quotes
	 * iff needed.
	 * If no space, tab, or quote - leave unchanged.
	 * Else print surrounded by " or ', swapping quotes
	 * when we find one that will cause confusion.
	 */

	char first_quote = 0, q;
	char *c;

	for (c = str; *c; c++) {
		switch(*c) {
		case '\'':
		case '"':
			first_quote = *c;
			break;
		case ' ':
		case '\t':
			first_quote = *c;
			continue;
		default:
			continue;
		}
		break;
	}
	if (!first_quote) {
		printf("%s", str);
		return;
	}

	if (first_quote == '"')
		q = '\'';
	else
		q = '"';
	putchar(q);
	for (c = str; *c; c++) {
		if (*c == q) {
			putchar(q);
			q ^= '"' ^ '\'';
			putchar(q);
		}
		putchar(*c);
	}
	putchar(q);
}

void print_escape(char *str)
{
	/* print str, but change space and tab to '_'
	 * as is suitable for device names
	 */
	for (; *str ; str++) {
		switch (*str) {
		case ' ':
		case '\t':
			putchar('_');
			break;
		case '/':
			putchar('-');
			break;
		default:
			putchar(*str);
		}
	}
}

int use_udev(void)
{
	static int use = -1;
	struct stat stb;

	if (use < 0) {
		use = ((stat("/dev/.udev", &stb) == 0
			|| stat("/run/udev", &stb) == 0)
		       && check_env("MDADM_NO_UDEV") == 0);
	}
	return use;
}
Commit	Line	Data
78c0a3b1 N	1	/*
	2	* mdadm - manage Linux "md" devices aka RAID arrays.
	3	*
	4	* Copyright (C) 2011 Neil Brown <neilb@suse.de>
	5	*
	6	*
	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.
	11	*
	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.
	16	*
	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
	20	*
	21	* Author: Neil Brown
	22	* Email: <neilb@suse.de>
	23	*/
	24
	25	#include "mdadm.h"
	26	#include <ctype.h>
	27
	28	/* This fill contains various 'library' style function. They
	29	* have no dependency on anything outside this file.
	30	*/
	31
	32	int get_mdp_major(void)
	33	{
	34	static int mdp_major = -1;
	35	FILE *fl;
	36	char *w;
	37	int have_block = 0;
	38	int have_devices = 0;
	39	int last_num = -1;
	40
	41	if (mdp_major != -1)
	42	return mdp_major;
	43	fl = fopen("/proc/devices", "r");
	44	if (!fl)
	45	return -1;
	46	while ((w = conf_word(fl, 1))) {
	47	if (have_block && strcmp(w, "devices:")==0)
	48	have_devices = 1;
	49	have_block = (strcmp(w, "Block")==0);
	50	if (isdigit(w[0]))
	51	last_num = atoi(w);
	52	if (have_devices && strcmp(w, "mdp")==0)
	53	mdp_major = last_num;
	54	free(w);
	55	}
	56	fclose(fl);
	57	return mdp_major;
	58	}
	59
4dd2df09	60	char *devid2devnm(int devid)
78c0a3b1 N	61	{
	62	char path[30];
	63	char link[200];
4dd2df09 N	64	static char devnm[32];
4dd2df09 N	65	char cp, ep;
78c0a3b1 N	66	int n;
78c0a3b1 N	67
4dd2df09 N	68	/* Might be an extended-minor partition or a
	69	* named md device. Look at the
	70	* /sys/dev/block/%d:%d link which must look like
	71	* ../../block/mdXXX/mdXXXpYY
	72	* or
	73	* ...../block/md_FOO
	74	*/
	75	sprintf(path, "/sys/dev/block/%d:%d", major(devid),
	76	minor(devid));
	77	n = readlink(path, link, sizeof(link)-1);
	78	if (n > 0) {
78c0a3b1	79	link[n] = 0;
4dd2df09 N	80	cp = strstr(link, "/block/");
	81	if (cp) {
	82	cp += 7;
	83	ep = strchr(cp, '/');
	84	if (ep)
	85	*ep = 0;
	86	strcpy(devnm, cp);
	87	return devnm;
	88	}
78c0a3b1	89	}
4dd2df09 N	90	if (major(devid) == MD_MAJOR)
	91	sprintf(devnm,"md%d", minor(devid));
	92	else if (major(devid) == (unsigned)get_mdp_major())
	93	sprintf(devnm,"md_d%d",
	94	(minor(devid)>>MdpMinorShift));
	95	else
	96	return NULL;
	97	return devnm;
	98	}
78c0a3b1	99
4dd2df09 N	100	char stat2devnm(struct stat st)
	101	{
	102	if ((S_IFMT & st->st_mode) != S_IFBLK)
	103	return NULL;
	104	return devid2devnm(st->st_rdev);
78c0a3b1 N	105	}
78c0a3b1 N	106
4dd2df09	107	char *fd2devnm(int fd)
78c0a3b1 N	108	{
	109	struct stat stb;
	110	if (fstat(fd, &stb) == 0)
4dd2df09 N	111	return stat2devnm(&stb);
4dd2df09 N	112	return NULL;
78c0a3b1 N	113	}
	114
	115
	116
	117	/*
	118	* convert a major/minor pair for a block device into a name in /dev, if possible.
	119	* On the first call, walk /dev collecting name.
	120	* Put them in a simple linked listfor now.
	121	*/
	122	struct devmap {
5d500228 N	123	int major, minor;
	124	char *name;
	125	struct devmap *next;
78c0a3b1 N	126	} *devlist = NULL;
	127	int devlist_ready = 0;
	128
	129	int add_dev(const char name, const struct stat stb, int flag, struct FTW *s)
	130	{
	131	struct stat st;
	132
	133	if (S_ISLNK(stb->st_mode)) {
	134	if (stat(name, &st) != 0)
	135	return 0;
	136	stb = &st;
	137	}
	138
	139	if ((stb->st_mode&S_IFMT)== S_IFBLK) {
503975b9 N	140	char *n = xstrdup(name);
503975b9 N	141	struct devmap dm = xmalloc(sizeof(dm));
78c0a3b1 N	142	if (strncmp(n, "/dev/./", 7)==0)
	143	strcpy(n+4, name+6);
	144	if (dm) {
	145	dm->major = major(stb->st_rdev);
	146	dm->minor = minor(stb->st_rdev);
	147	dm->name = n;
	148	dm->next = devlist;
	149	devlist = dm;
	150	}
	151	}
	152	return 0;
	153	}
	154
	155	#ifndef HAVE_NFTW
	156	#ifdef HAVE_FTW
	157	int add_dev_1(const char name, const struct stat stb, int flag)
	158	{
	159	return add_dev(name, stb, flag, NULL);
	160	}
	161	int nftw(const char path, int (han)(const char name, const struct stat stb, int flag, struct FTW *s), int nopenfd, int flags)
	162	{
	163	return ftw(path, add_dev_1, nopenfd);
	164	}
	165	#else
	166	int nftw(const char path, int (han)(const char name, const struct stat stb, int flag, struct FTW *s), int nopenfd, int flags)
	167	{
	168	return 0;
	169	}
	170	#endif /* HAVE_FTW */
	171	#endif /* HAVE_NFTW */
	172
	173	/*
	174	* Find a block device with the right major/minor number.
	175	* If we find multiple names, choose the shortest.
	176	* If we find a name in /dev/md/, we prefer that.
	177	* This applies only to names for MD devices.
c2ecf5f6 N	178	* If 'prefer' is set (normally to e.g. /by-path/)
c2ecf5f6 N	179	* then we prefer a name which contains that string.
78c0a3b1	180	*/
c2ecf5f6 N	181	char *map_dev_preferred(int major, int minor, int create,
c2ecf5f6 N	182	char *prefer)
78c0a3b1 N	183	{
	184	struct devmap *p;
	185	char regular = NULL, preferred=NULL;
	186	int did_check = 0;
	187
	188	if (major == 0 && minor == 0)
	189	return NULL;
	190
	191	retry:
	192	if (!devlist_ready) {
	193	char *dev = "/dev";
	194	struct stat stb;
	195	while(devlist) {
	196	struct devmap *d = devlist;
	197	devlist = d->next;
	198	free(d->name);
	199	free(d);
	200	}
	201	if (lstat(dev, &stb)==0 &&
	202	S_ISLNK(stb.st_mode))
	203	dev = "/dev/.";
	204	nftw(dev, add_dev, 10, FTW_PHYS);
	205	devlist_ready=1;
	206	did_check = 1;
	207	}
	208
	209	for (p=devlist; p; p=p->next)
	210	if (p->major == major &&
	211	p->minor == minor) {
c2ecf5f6 N	212	if (strncmp(p->name, "/dev/md/",8) == 0
c2ecf5f6 N	213	\|\| (prefer && strstr(p->name, prefer))) {
78c0a3b1 N	214	if (preferred == NULL \|\|
	215	strlen(p->name) < strlen(preferred))
	216	preferred = p->name;
	217	} else {
	218	if (regular == NULL \|\|
	219	strlen(p->name) < strlen(regular))
	220	regular = p->name;
	221	}
	222	}
	223	if (!regular && !preferred && !did_check) {
	224	devlist_ready = 0;
	225	goto retry;
	226	}
	227	if (create && !regular && !preferred) {
	228	static char buf[30];
	229	snprintf(buf, sizeof(buf), "%d:%d", major, minor);
	230	regular = buf;
	231	}
	232
	233	return preferred ? preferred : regular;
	234	}
	235
	236
c2ecf5f6	237
78c0a3b1 N	238	/* conf_word gets one word from the conf file.
	239	* if "allow_key", then accept words at the start of a line,
	240	* otherwise stop when such a word is found.
	241	* We assume that the file pointer is at the end of a word, so the
	242	* next character is a space, or a newline. If not, it is the start of a line.
	243	*/
	244
	245	char conf_word(FILE file, int allow_key)
	246	{
	247	int wsize = 100;
	248	int len = 0;
	249	int c;
	250	int quote;
	251	int wordfound = 0;
503975b9	252	char *word = xmalloc(wsize);
78c0a3b1 N	253
	254	while (wordfound==0) {
	255	/* at the end of a word.. */
	256	c = getc(file);
	257	if (c == '#')
	258	while (c != EOF && c != '\n')
	259	c = getc(file);
	260	if (c == EOF) break;
	261	if (c == '\n') continue;
	262
	263	if (c != ' ' && c != '\t' && ! allow_key) {
	264	ungetc(c, file);
	265	break;
	266	}
	267	/* looks like it is safe to get a word here, if there is one */
	268	quote = 0;
	269	/* first, skip any spaces */
	270	while (c == ' ' \|\| c == '\t')
	271	c = getc(file);
	272	if (c != EOF && c != '\n' && c != '#') {
	273	/* we really have a character of a word, so start saving it */
	274	while (c != EOF && c != '\n' && (quote \|\| (c!=' ' && c != '\t'))) {
	275	wordfound = 1;
	276	if (quote && c == quote) quote = 0;
	277	else if (quote == 0 && (c == '\'' \|\| c == '"'))
	278	quote = c;
	279	else {
	280	if (len == wsize-1) {
	281	wsize += 100;
503975b9	282	word = xrealloc(word, wsize);
78c0a3b1 N	283	}
	284	word[len++] = c;
	285	}
	286	c = getc(file);
	287	/* Hack for broken kernels (2.6.14-.24) that put
	288	* "active(auto-read-only)"
	289	* in /proc/mdstat instead of
	290	* "active (auto-read-only)"
	291	*/
	292	if (c == '(' && len >= 6
	293	&& strncmp(word+len-6, "active", 6) == 0)
	294	c = ' ';
	295	}
	296	}
	297	if (c != EOF) ungetc(c, file);
	298	}
	299	word[len] = 0;
	300
	301	/* Further HACK for broken kernels.. 2.6.14-2.6.24 */
	302	if (strcmp(word, "auto-read-only)") == 0)
	303	strcpy(word, "(auto-read-only)");
	304
	305	/* printf("word is <%s>\n", word); */
	306	if (!wordfound) {
	307	free(word);
	308	word = NULL;
	309	}
	310	return word;
	311	}
7103b9b8 N	312
	313	void print_quoted(char *str)
	314	{
	315	/* Printf the string with surrounding quotes
	316	* iff needed.
	317	* If no space, tab, or quote - leave unchanged.
	318	* Else print surrounded by " or ', swapping quotes
	319	* when we find one that will cause confusion.
	320	*/
	321
	322	char first_quote = 0, q;
	323	char *c;
	324
	325	for (c = str; *c; c++) {
	326	switch(*c) {
	327	case '\'':
	328	case '"':
	329	first_quote = *c;
	330	break;
	331	case ' ':
	332	case '\t':
	333	first_quote = *c;
	334	continue;
	335	default:
	336	continue;
	337	}
	338	break;
	339	}
	340	if (!first_quote) {
	341	printf("%s", str);
	342	return;
	343	}
	344
	345	if (first_quote == '"')
	346	q = '\'';
	347	else
	348	q = '"';
	349	putchar(q);
	350	for (c = str; *c; c++) {
	351	if (*c == q) {
	352	putchar(q);
	353	q ^= '"' ^ '\'';
	354	putchar(q);
	355	}
	356	putchar(*c);
	357	}
	358	putchar(q);
	359	}
	360
	361	void print_escape(char *str)
	362	{
	363	/* print str, but change space and tab to '_'
	364	* as is suitable for device names
	365	*/
	366	for (; *str ; str++) {
	367	switch (*str) {
	368	case ' ':
	369	case '\t':
	370	putchar('_');
	371	break;
	372	case '/':
	373	putchar('-');
	374	break;
	375	default:
376	putchar(*str);
377	}
378	}
379	}
06d2ffc3 N	380
	381	int use_udev(void)
	382	{
	383	static int use = -1;
	384	struct stat stb;
	385
	386	if (use < 0) {
	387	use = ((stat("/dev/.udev", &stb) == 0
	388	\|\| stat("/run/udev", &stb) == 0)
	389	&& check_env("MDADM_NO_UDEV") == 0);
	390	}
	391	return use;
	392	}