o I've moved the dev-cache and dev-io into here since this directory has a

better name.  dev-mgr will be removed at some point.

lib/device/dev-cache.c

@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dev-cache.h"
+#include "log.h"
+#include "pool.h"
+#include "hash.h"
+#include "list.h"
+#include "dbg_malloc.h"
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <sys/param.h>
+#include <dirent.h>
+
+/*
+ * FIXME: really need to seperate names from the devices since
+ * multiple names can point to the same device.
+ */
+
+struct dev_iter {
+	struct hash_node *current;
+	struct dev_filter *filter;
+};
+
+struct dir_list {
+	struct list_head list;
+	char dir[0];
+};
+
+static struct {
+	struct pool *mem;
+	struct hash_table *devices;
+
+	int has_scanned;
+	struct list_head dirs;
+
+} _cache;
+
+
+#define _alloc(x) pool_alloc(_cache.mem, (x))
+#define _free(x) pool_free(_cache.mem, (x))
+
+/*
+ * return a new path for the destination of the path.
+ */
+static char *_follow_link(const char *path, struct stat *info)
+{
+	char buffer[PATH_MAX + 1];
+	int n;
+	n = readlink(path, buffer, sizeof(buffer) - 1);
+
+	if (n <= 0)
+		return NULL;
+
+	buffer[n] = '\0';
+
+	if (stat(buffer, info) < 0) {
+		log_sys_err("stat");
+		return NULL;
+	}
+
+	return pool_strdup(_cache.mem, buffer);
+}
+
+/*
+ * Get rid of extra slashes in the path string.
+ */
+static void _collapse_slashes(char *str)
+{
+	char *ptr;
+	int was_slash = 0;
+
+	for (ptr = str; *ptr; ptr++) {
+		if (*ptr == '/') {
+			if (was_slash)
+				continue;
+
+			was_slash = 1;
+		} else
+			was_slash = 0;
+		*str++ = *ptr;
+	}
+
+	*str = *ptr;
+}
+
+static struct device *_create_dev(const char *path)
+{
+	struct stat info;
+	struct device *dev;
+	char *name = pool_strdup(_cache.mem, path);
+
+	if (!name) {
+		stack;
+		return NULL;
+	}
+
+	_collapse_slashes(name);
+
+	if (stat(name, &info) < 0) {
+		log_sys_err("stat");
+		goto bad;
+	}
+
+	if (S_ISLNK(info.st_mode)) {
+		log_debug("%s is a symbolic link, following\n", name);
+		if (!(name = _follow_link(name, &info))) {
+			stack;
+			goto bad;
+		}
+	}
+
+	if (!S_ISBLK(info.st_mode)) {
+		log_debug("%s is not a block device\n", name);
+		goto bad;
+	}
+
+	if (!(dev = _alloc(sizeof(*dev)))) {
+		stack;
+		goto bad;
+	}
+
+	dev->name = name;
+	dev->dev = info.st_rdev;
+	return dev;
+
+ bad:
+	_free(name);
+	return NULL;
+}
+
+static struct device *_add(const char *dir, const char *path)
+{
+	struct device *d;
+	int len = strlen(dir) + strlen(path) + 2;
+	char *buffer = dbg_malloc(len);
+
+	snprintf(buffer, len, "%s/%s", dir, path);
+	d = dev_cache_get(buffer, NULL);
+	dbg_free(buffer);
+
+	return d;
+}
+
+static int _dir_scan(const char *dir)
+{
+	int n, dirent_count;
+	struct dirent **dirent;
+
+	dirent_count = scandir(dir, &dirent, NULL, alphasort);
+	if (dirent_count > 0) {
+		for (n = 0; n < dirent_count; n++) {
+			_add(dir, dirent[n]->d_name);
+			free(dirent[n]);
+		}
+		free(dirent);
+	}
+
+	return 1;
+}
+
+static void _full_scan(void)
+{
+	struct list_head *tmp;
+
+	if (_cache.has_scanned)
+		return;
+
+	list_for_each(tmp, &_cache.dirs) {
+		struct dir_list *dl = list_entry(tmp, struct dir_list, list);
+		_dir_scan(dl->dir);
+	}
+
+	_cache.has_scanned = 1;
+}
+
+int dev_cache_init(void)
+{
+	if (!(_cache.mem = pool_create(10 * 1024))) {
+		stack;
+		return 0;
+	}
+
+	if (!(_cache.devices = hash_create(128))) {
+		stack;
+		pool_destroy(_cache.mem);
+		_cache.mem = 0;
+		return 0;
+	}
+
+	return 1;
+}
+
+void dev_cache_exit(void)
+{
+	pool_destroy(_cache.mem);
+	hash_destroy(_cache.devices);
+}
+
+int dev_cache_add_dir(const char *path)
+{
+	struct dir_list *dl;
+
+	if (!(dl = _alloc(sizeof(*dl) + strlen(path) + 1)))
+		return 0;
+
+	strcpy(dl->dir, path);
+	list_add(&dl->list, &_cache.dirs);
+	return 1;
+}
+
+struct device *_insert_new(const char *name)
+{
+	struct device *d = _create_dev(name);
+	if (!d || !hash_insert(_cache.devices, name, d))
+		return NULL;
+
+	return d;
+}
+
+struct device *dev_cache_get(const char *name, struct dev_filter *f)
+{
+	struct device *d = (struct device *) hash_lookup(_cache.devices, name);
+	return (d && (!f || f->passes_filter(f, d))) ? d : NULL;
+}
+
+struct dev_iter *dev_iter_create(struct dev_filter *f)
+{
+	struct dev_iter *di = dbg_malloc(sizeof(*di));
+
+	if (!di)
+		return NULL;
+
+	_full_scan();
+	di->current = hash_get_first(_cache.devices);
+	di->filter = f;
+
+	return di;
+}
+
+void dev_iter_destroy(struct dev_iter *iter)
+{
+	dbg_free(iter);
+}
+
+static inline struct device *_iter_next(struct dev_iter *iter)
+{
+	struct device *d = hash_get_data(_cache.devices, iter->current);
+	iter->current = hash_get_next(_cache.devices, iter->current);
+	return d;
+}
+
+struct device *dev_iter_get(struct dev_iter *iter)
+{
+	while (iter->current) {
+		struct device *d = _iter_next(iter);
+		if (!iter->filter ||
+		    iter->filter->passes_filter(iter->filter, d))
+			return d;
+	}
+
+	return NULL;
+}
+
+
+

lib/device/dev-cache.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef _LVM_DEV_CACHE_H
+#define _LVM_DEV_CACHE_H
+
+#include <sys/types.h>
+#include "lvm-types.h"
+#include "device.h"
+
+/*
+ * predicate for devices.
+ */
+struct dev_filter {
+	int (*passes_filter)(struct dev_filter *f, struct device *dev);
+	void *private;
+};
+
+
+/*
+ * The global device cache.
+ */
+int dev_cache_init(void);
+void dev_cache_exit(void);
+
+int dev_cache_add_dir(const char *path);
+struct device *dev_cache_get(const char *name, struct dev_filter *f);
+
+
+/*
+ * Object for iterating through the cache.
+ */
+struct dev_iter;
+struct dev_iter *dev_iter_create(struct dev_filter *f);
+void dev_iter_destroy(struct dev_iter *iter);
+struct device *dev_iter_get(struct dev_iter *iter);
+
+#endif

lib/device/dev-io.c

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2001 Sistina Software
+ *
+ * This file is released under the GPL.
+ */
+
+int dev_get_size(struct device *dev, uint64_t *size)
+{
+	int fd;
+	long s;
+
+	log_verbose("Getting device size");
+	if ((fd = open(pv, O_RDONLY)) < 0) {
+		log_sys_error("open");
+		return 0;
+	}
+
+	/* FIXME: add 64 bit ioctl */
+	if (ioctl(fd, BLKGETSIZE, &s) < 0) {
+		log_sys_err("ioctl");
+		close(fd);
+		return 0;
+	}
+
+	close(fd);
+	*size = (uint64_t) s;
+	return 1;
+}
+
+int64_t dev_read(struct device *dev, uint64_t offset,
+		 int64_t len, void *buffer)
+{
+	// FIXME: lazy programmer
+	return 0;
+}
+
+int64_t dev_write(struct device *dev, uint64_t offset,
+		  int64_t len, void *buffer)
+{
+	// FIXME: lazy programmer
+	return 0;
+}

lib/device/device.c

@@ -38,11 +38,11 @@
 #include <linux/major.h>
 #include <linux/genhd.h>
 
-int _get_partition_type(struct dev_mgr *dm, struct device *d);
+int _get_partition_type(struct dev_filter *filter, struct device *d);
 
 #define MINOR_PART(dm, d) (MINOR((d)->dev) % dev_max_partitions(dm, (d)->dev))
 
-int is_whole_disk(struct dev_mgr *dm, struct device *d)
+int is_whole_disk(struct dev_filter *filter, struct device *d)
 {
 	return (MINOR_PART(dm, d)) ? 0 : 1;
 }

lib/device/device.h

@@ -1,27 +1,36 @@
 /*
- * Copyright (C) 2001 Sistina Software
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
  *
- * This LVM library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This LVM library 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
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this LVM library; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA
+ * This file is released under the GPL.
  */
 
 #ifndef _LVM_DEVICE_H
 #define _LVM_DEVICE_H
 
-int do_ioctl(const char *file, int mode, unsigned long cmd, void *req);
-int device_get_size(const char *dev_name);
+#include "lvm-types.h"
+
+/*
+ * All devices in LVM will be represented by one of these.
+ * pointer comparisons are valid.
+ */
+struct device {
+	char *name;
+	dev_t dev;
+};
+
+/*
+ * All io should use these routines, rather than opening the devices
+ * by hand.  You do not have to call an open routine.  ATM all io is
+ * immediately flushed.
+ */
+int dev_get_size(struct device *dev, uint64_t *size);
+int64_t dev_read(struct device *dev,
+		 uint64_t offset, int64_t len, void *buffer);
+int64_t dev_write(struct device *dev,
+		  uint64_t offset, int64_t len, void *buffer);
+
+/* FIXME: Alasdair lets add more query functions here for accessing
+   the partition information, this can then be used by your filter. */
 
 #endif