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/* device.c - Device access */
/* Copyright 1992-1997 Werner Almesberger. See file COPYING for details. */
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <dirent.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "config.h"
#include "common.h"
#include "temp.h"
#include "device.h"
typedef struct _cache_entry {
const char *name;
int number;
struct _cache_entry *next;
} CACHE_ENTRY;
typedef struct _st_buf {
struct _st_buf *next;
struct stat st;
} ST_BUF;
static CACHE_ENTRY *cache = NULL;
static int scan_dir(ST_BUF *next,DEVICE *dev,char *parent,int number)
{
DIR *dp;
struct dirent *dir;
ST_BUF st,*walk;
char *start;
st.next = next;
if ((dp = opendir(parent)) == NULL)
die("opendir %s: %s",parent,strerror(errno));
*(start = strchr(parent,0)) = '/';
while ((dir = readdir(dp))) {
strcpy(start+1,dir->d_name);
if (stat(parent,&st.st) >= 0) {
dev->st = st.st;
if (S_ISBLK(dev->st.st_mode) && dev->st.st_rdev == number) {
(void) closedir(dp);
return 1;
}
if (S_ISDIR(dev->st.st_mode) && strcmp(dir->d_name,".") &&
strcmp(dir->d_name,"..")) {
for (walk = next; walk; walk = walk->next)
if (stat_equal(&walk->st,&st.st)) break;
if (!walk && scan_dir(&st,dev,parent,number)) {
(void) closedir(dp);
return 1;
}
}
}
}
(void) closedir(dp);
*start = 0;
return 0;
}
static int lookup_dev(char *name,DEVICE *dev,int number)
{
CACHE_ENTRY **walk,*here;
for (walk = &cache; *walk; walk = &(*walk)->next)
if ((*walk)->number == number) {
if (stat((*walk)->name,&dev->st) >= 0)
if (S_ISBLK(dev->st.st_mode) && dev->st.st_rdev == number) {
strcpy(name,(*walk)->name);
return 1;
}
here = *walk; /* remove entry from cache */
if (verbose >= 2)
printf("Invalidating cache entry for %s (0x%04X)\n",here->name,
here->number);
*walk = here->next;
free((char *) here->name);
free(here);
return 0;
}
return 0;
}
static void cache_add(const char *name,int number)
{
CACHE_ENTRY *entry;
if (verbose >= 3) printf("Caching device %s (0x%04X)\n",name,number);
entry = alloc_t(CACHE_ENTRY);
entry->name = stralloc(name);
entry->number = number;
entry->next = cache;
cache = entry;
}
int dev_open(DEVICE *dev,int number,int flags)
{
char name[PATH_MAX+1];
ST_BUF st;
int count;
if (lookup_dev(name,dev,number)) dev->delete = 0;
else {
if (stat(DEV_DIR,&st.st) < 0)
die("stat " DEV_DIR ": %s",strerror(errno));
st.next = NULL;
dev->delete = !scan_dir(&st,dev,strcpy(name,DEV_DIR),number);
if (dev->delete) {
for (count = 0; count <= MAX_TMP_DEV; count++) {
#ifdef LCF_USE_TMPDIR
if (!strncmp(TMP_DEV,"/tmp/",5) && getenv("TMPDIR")) {
strcpy(name,getenv("TMPDIR"));
sprintf(name+strlen(name),TMP_DEV+4,count);
}
else
#endif
sprintf(name,TMP_DEV,count);
if (stat(name,&dev->st) < 0) break;
}
if (count > MAX_TMP_DEV)
die("Failed to create a temporary device");
if (mknod(name,0600 | S_IFBLK,number) < 0)
die("mknod %s: %s",name,strerror(errno));
if (stat(name,&dev->st) < 0)
die("stat %s: %s",name,strerror(errno));
if (verbose > 1)
printf("Created temporary device %s (0x%04X)\n",name,number);
temp_register(name);
}
else cache_add(name,number);
}
if (flags == -1) dev->fd = -1;
else if ((dev->fd = open(name,flags)) < 0)
die("open %s: %s",name,strerror(errno));
dev->name = stralloc(name);
return dev->fd;
}
void dev_close(DEVICE *dev)
{
if (dev->fd != -1)
if (close(dev->fd) < 0) die("close %s: %s",dev->name,strerror(errno));
if (dev->delete) {
if (verbose > 1)
printf("Removed temporary device %s (0x%04X)\n",dev->name,
(unsigned int) dev->st.st_rdev);
(void) remove(dev->name);
temp_unregister(dev->name);
}
free(dev->name);
}
void preload_dev_cache(void)
{
char tmp[10];
int i;
cache_add("/dev/hda",0x300);
for (i = 1; i <= 8; i++) {
sprintf(tmp,"/dev/hda%d",i);
cache_add(tmp,0x300+i);
}
cache_add("/dev/hdb",0x340);
for (i = 1; i <= 8; i++) {
sprintf(tmp,"/dev/hdb%d",i);
cache_add(tmp,0x340+i);
}
cache_add("/dev/sda",0x800);
for (i = 1; i <= 8; i++) {
sprintf(tmp,"/dev/sda%d",i);
cache_add(tmp,0x800+i);
}
cache_add("/dev/sdb",0x810);
for (i = 1; i <= 8; i++) {
sprintf(tmp,"/dev/sdb%d",i);
cache_add(tmp,0x810+i);
}
}
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