Split some of util.c into a new lib.c

Some of util.c is dependent on lots of other code, some of it
is stand-alone.
Move some of the stand-alone stuff into a new lib.c so it can be used
by smaller utilities.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 322 insertions, 0 deletions

diff --git a/lib.c b/lib.c
new file mode 100644
index 00000000..2739b3d3
--- /dev/null
+++ b/lib.c
@@ -0,0 +1,322 @@
+/*
+ * 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;
+}
+
+
+void fmt_devname(char *name, int num)
+{
+	if (num >= 0)
+		sprintf(name, "md%d", num);
+	else
+		sprintf(name, "md_d%d", -1-num);
+}
+
+char *devnum2devname(int num)
+{
+	char name[100];
+	fmt_devname(name,num);
+	return strdup(name);
+}
+
+int devname2devnum(char *name)
+{
+	char *ep;
+	int num;
+	if (strncmp(name, "md_d", 4)==0)
+		num = -1-strtoul(name+4, &ep, 10);
+	else
+		num = strtoul(name+2, &ep, 10);
+	return num;
+}
+
+int stat2devnum(struct stat *st)
+{
+	char path[30];
+	char link[200];
+	char *cp;
+	int n;
+
+	if ((S_IFMT & st->st_mode) == S_IFBLK) {
+		if (major(st->st_rdev) == MD_MAJOR)
+			return minor(st->st_rdev);
+		else if (major(st->st_rdev) == (unsigned)get_mdp_major())
+			return -1- (minor(st->st_rdev)>>MdpMinorShift);
+
+		/* must be an extended-minor partition. Look at the
+		 * /sys/dev/block/%d:%d link which must look like
+		 * ../../block/mdXXX/mdXXXpYY
+		 */
+		sprintf(path, "/sys/dev/block/%d:%d", major(st->st_rdev),
+			minor(st->st_rdev));
+		n = readlink(path, link, sizeof(link)-1);
+		if (n <= 0)
+			return NoMdDev;
+		link[n] = 0;
+		cp = strrchr(link, '/');
+		if (cp) *cp = 0;
+		cp = strrchr(link, '/');
+		if (cp && strncmp(cp, "/md", 3) == 0)
+			return devname2devnum(cp+1);
+	}
+	return NoMdDev;
+
+}
+
+int fd2devnum(int fd)
+{
+	struct stat stb;
+	if (fstat(fd, &stb) == 0)
+		return stat2devnum(&stb);
+	return NoMdDev;
+}
+
+
+
+/*
+ * 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 = strdup(name);
+		struct devmap *dm = malloc(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.
+ */
+char *map_dev(int major, int minor, int create)
+{
+	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) {
+				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 = malloc(wsize);
+
+	if (!word) abort();
+
+	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 = realloc(word, wsize);
+						if (!word) abort();
+					}
+					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;
+}