freebsd-dev/stand/common/misc.c
Toomas Soome b4cb3fe0e3 loader: implement mount/unmount rootfs
We want to keep our root file system open to preserve bcache segment
between file accesses, thus reducing physical disk IO.

Reviewed by:	imp, allanjude, kevans (previous version)
Differential Revision:	https://reviews.freebsd.org/D30848
MFC after:	1 month
2021-09-08 04:01:20 +03:00

204 lines
4.6 KiB
C

/*-
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <string.h>
#include <stand.h>
#include <bootstrap.h>
/*
* Concatenate the (argc) elements of (argv) into a single string, and return
* a copy of same.
*/
char *
unargv(int argc, char *argv[])
{
size_t hlong;
int i;
char *cp;
for (i = 0, hlong = 0; i < argc; i++)
hlong += strlen(argv[i]) + 2;
if(hlong == 0)
return(NULL);
cp = malloc(hlong);
cp[0] = 0;
for (i = 0; i < argc; i++) {
strcat(cp, argv[i]);
if (i < (argc - 1))
strcat(cp, " ");
}
return(cp);
}
/*
* Get the length of a string in kernel space
*/
size_t
strlenout(vm_offset_t src)
{
char c;
size_t len;
for (len = 0; ; len++) {
archsw.arch_copyout(src++, &c, 1);
if (c == 0)
break;
}
return(len);
}
/*
* Make a duplicate copy of a string in kernel space
*/
char *
strdupout(vm_offset_t str)
{
char *result, *cp;
result = malloc(strlenout(str) + 1);
for (cp = result; ;cp++) {
archsw.arch_copyout(str++, cp, 1);
if (*cp == 0)
break;
}
return(result);
}
/* Zero a region in kernel space. */
void
kern_bzero(vm_offset_t dest, size_t len)
{
char buf[256];
size_t chunk, resid;
bzero(buf, sizeof(buf));
resid = len;
while (resid > 0) {
chunk = min(sizeof(buf), resid);
archsw.arch_copyin(buf, dest, chunk);
resid -= chunk;
dest += chunk;
}
}
/*
* Read the specified part of a file to kernel space. Unlike regular
* pread, the file pointer is advanced to the end of the read data,
* and it just returns 0 if successful.
*/
int
kern_pread(readin_handle_t fd, vm_offset_t dest, size_t len, off_t off)
{
if (VECTX_LSEEK(fd, off, SEEK_SET) == -1) {
#ifdef DEBUG
printf("\nlseek failed\n");
#endif
return (-1);
}
if ((size_t)archsw.arch_readin(fd, dest, len) != len) {
#ifdef DEBUG
printf("\nreadin failed\n");
#endif
return (-1);
}
return (0);
}
/*
* Read the specified part of a file to a malloced buffer. The file
* pointer is advanced to the end of the read data.
*/
/* coverity[ -tainted_data_return ] */
void *
alloc_pread(readin_handle_t fd, off_t off, size_t len)
{
void *buf;
buf = malloc(len);
if (buf == NULL) {
#ifdef DEBUG
printf("\nmalloc(%d) failed\n", (int)len);
#endif
errno = ENOMEM;
return (NULL);
}
if (VECTX_LSEEK(fd, off, SEEK_SET) == -1) {
#ifdef DEBUG
printf("\nlseek failed\n");
#endif
free(buf);
return (NULL);
}
if ((size_t)VECTX_READ(fd, buf, len) != len) {
#ifdef DEBUG
printf("\nread failed\n");
#endif
free(buf);
return (NULL);
}
return (buf);
}
void
dev_cleanup(void)
{
int i;
/* Call cleanup routines */
for (i = 0; devsw[i] != NULL; ++i)
if (devsw[i]->dv_cleanup != NULL)
(devsw[i]->dv_cleanup)();
}
/*
* mount new rootfs and unmount old, set "currdev" environment variable.
*/
int mount_currdev(struct env_var *ev, int flags, const void *value)
{
int rv;
/* mount new rootfs */
rv = mount(value, "/", 0, NULL);
if (rv == 0) {
/*
* Note we unmount any previously mounted fs only after
* successfully mounting the new because we do not want to
* end up with unmounted rootfs.
*/
if (ev->ev_value != NULL)
unmount(ev->ev_value, 0);
env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
}
return (rv);
}