freebsd-dev/sys/boot/i386/loader/main.c
Allan Jude 87ed2b7f5a A new implementation of the loader block cache
The block cache implementation in loader has proven to be almost useless, and in worst case even slowing down the disk reads due to insufficient cache size and extra memory copy.
Also the current cache implementation does not cache reads from CDs, or work with zfs built on top of multiple disks.
Instead of an LRU, this code uses a simple hash (O(1) read from cache), and instead of a single global cache, a separate cache per block device.
The cache also implements limited read-ahead to increase performance.
To simplify read ahead management, the read ahead will not wrap over bcache end, so in worst case, single block physical read will be performed to fill the last block in bcache.

Booting from a virtual CD over IPMI:
0ms latency, before: 27 second, after: 7 seconds
60ms latency, before: over 12 minutes, after: under 5 minutes.

Submitted by:	Toomas Soome <tsoome@me.com>
Reviewed by:	delphij (previous version), emaste (previous version)
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D4713
2016-04-18 23:09:22 +00:00

460 lines
13 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("$FreeBSD$");
/*
* MD bootstrap main() and assorted miscellaneous
* commands.
*/
#include <stand.h>
#include <stddef.h>
#include <string.h>
#include <machine/bootinfo.h>
#include <machine/cpufunc.h>
#include <machine/psl.h>
#include <sys/reboot.h>
#include "bootstrap.h"
#include "common/bootargs.h"
#include "libi386/libi386.h"
#include "libi386/smbios.h"
#include "btxv86.h"
#ifdef LOADER_ZFS_SUPPORT
#include "../zfs/libzfs.h"
#endif
CTASSERT(sizeof(struct bootargs) == BOOTARGS_SIZE);
CTASSERT(offsetof(struct bootargs, bootinfo) == BA_BOOTINFO);
CTASSERT(offsetof(struct bootargs, bootflags) == BA_BOOTFLAGS);
CTASSERT(offsetof(struct bootinfo, bi_size) == BI_SIZE);
/* Arguments passed in from the boot1/boot2 loader */
static struct bootargs *kargs;
static u_int32_t initial_howto;
static u_int32_t initial_bootdev;
static struct bootinfo *initial_bootinfo;
struct arch_switch archsw; /* MI/MD interface boundary */
static void extract_currdev(void);
static int isa_inb(int port);
static void isa_outb(int port, int value);
void exit(int code);
#ifdef LOADER_GELI_SUPPORT
struct geli_boot_args *gargs;
#endif
#ifdef LOADER_ZFS_SUPPORT
struct zfs_boot_args *zargs;
static void i386_zfs_probe(void);
#endif
/* from vers.c */
extern char bootprog_name[], bootprog_rev[], bootprog_date[], bootprog_maker[];
/* XXX debugging */
extern char end[];
static void *heap_top;
static void *heap_bottom;
int
main(void)
{
int i;
/* Pick up arguments */
kargs = (void *)__args;
initial_howto = kargs->howto;
initial_bootdev = kargs->bootdev;
initial_bootinfo = kargs->bootinfo ? (struct bootinfo *)PTOV(kargs->bootinfo) : NULL;
/* Initialize the v86 register set to a known-good state. */
bzero(&v86, sizeof(v86));
v86.efl = PSL_RESERVED_DEFAULT | PSL_I;
/*
* Initialise the heap as early as possible. Once this is done, malloc() is usable.
*/
bios_getmem();
#if defined(LOADER_BZIP2_SUPPORT) || defined(LOADER_FIREWIRE_SUPPORT) || \
defined(LOADER_GPT_SUPPORT) || defined(LOADER_ZFS_SUPPORT)
if (high_heap_size > 0) {
heap_top = PTOV(high_heap_base + high_heap_size);
heap_bottom = PTOV(high_heap_base);
if (high_heap_base < memtop_copyin)
memtop_copyin = high_heap_base;
} else
#endif
{
heap_top = (void *)PTOV(bios_basemem);
heap_bottom = (void *)end;
}
setheap(heap_bottom, heap_top);
/*
* XXX Chicken-and-egg problem; we want to have console output early, but some
* console attributes may depend on reading from eg. the boot device, which we
* can't do yet.
*
* We can use printf() etc. once this is done.
* If the previous boot stage has requested a serial console, prefer that.
*/
bi_setboothowto(initial_howto);
if (initial_howto & RB_MULTIPLE) {
if (initial_howto & RB_SERIAL)
setenv("console", "comconsole vidconsole", 1);
else
setenv("console", "vidconsole comconsole", 1);
} else if (initial_howto & RB_SERIAL)
setenv("console", "comconsole", 1);
else if (initial_howto & RB_MUTE)
setenv("console", "nullconsole", 1);
cons_probe();
/*
* Initialise the block cache. Set the upper limit.
*/
bcache_init(32768, 512);
/*
* Special handling for PXE and CD booting.
*/
if (kargs->bootinfo == 0) {
/*
* We only want the PXE disk to try to init itself in the below
* walk through devsw if we actually booted off of PXE.
*/
if (kargs->bootflags & KARGS_FLAGS_PXE)
pxe_enable(kargs->pxeinfo ? PTOV(kargs->pxeinfo) : NULL);
else if (kargs->bootflags & KARGS_FLAGS_CD)
bc_add(initial_bootdev);
}
archsw.arch_autoload = i386_autoload;
archsw.arch_getdev = i386_getdev;
archsw.arch_copyin = i386_copyin;
archsw.arch_copyout = i386_copyout;
archsw.arch_readin = i386_readin;
archsw.arch_isainb = isa_inb;
archsw.arch_isaoutb = isa_outb;
#ifdef LOADER_ZFS_SUPPORT
archsw.arch_zfs_probe = i386_zfs_probe;
#ifdef LOADER_GELI_SUPPORT
if ((kargs->bootflags & KARGS_FLAGS_EXTARG) != 0) {
zargs = (struct zfs_boot_args *)(kargs + 1);
if (zargs != NULL && zargs->size >= offsetof(struct zfs_boot_args, gelipw)) {
if (zargs->gelipw[0] != '\0') {
setenv("kern.geom.eli.passphrase", zargs->gelipw, 1);
bzero(zargs->gelipw, sizeof(zargs->gelipw));
}
}
}
#endif /* LOADER_GELI_SUPPORT */
#else /* !LOADER_ZFS_SUPPORT */
#ifdef LOADER_GELI_SUPPORT
if ((kargs->bootflags & KARGS_FLAGS_EXTARG) != 0) {
gargs = (struct geli_boot_args *)(kargs + 1);
if (gargs != NULL && gargs->size >= offsetof(struct geli_boot_args, gelipw)) {
if (gargs->gelipw[0] != '\0') {
setenv("kern.geom.eli.passphrase", gargs->gelipw, 1);
bzero(gargs->gelipw, sizeof(gargs->gelipw));
}
}
}
#endif /* LOADER_GELI_SUPPORT */
#endif /* LOADER_ZFS_SUPPORT */
/*
* March through the device switch probing for things.
*/
for (i = 0; devsw[i] != NULL; i++)
if (devsw[i]->dv_init != NULL)
(devsw[i]->dv_init)();
printf("BIOS %dkB/%dkB available memory\n", bios_basemem / 1024, bios_extmem / 1024);
if (initial_bootinfo != NULL) {
initial_bootinfo->bi_basemem = bios_basemem / 1024;
initial_bootinfo->bi_extmem = bios_extmem / 1024;
}
/* detect ACPI for future reference */
biosacpi_detect();
/* detect SMBIOS for future reference */
smbios_detect(NULL);
/* detect PCI BIOS for future reference */
biospci_detect();
printf("\n");
printf("%s, Revision %s\n", bootprog_name, bootprog_rev);
printf("(%s, %s)\n", bootprog_maker, bootprog_date);
extract_currdev(); /* set $currdev and $loaddev */
setenv("LINES", "24", 1); /* optional */
bios_getsmap();
interact(NULL);
/* if we ever get here, it is an error */
return (1);
}
/*
* Set the 'current device' by (if possible) recovering the boot device as
* supplied by the initial bootstrap.
*
* XXX should be extended for netbooting.
*/
static void
extract_currdev(void)
{
struct i386_devdesc new_currdev;
#ifdef LOADER_ZFS_SUPPORT
char buf[20];
#endif
int biosdev = -1;
/* Assume we are booting from a BIOS disk by default */
new_currdev.d_dev = &biosdisk;
/* new-style boot loaders such as pxeldr and cdldr */
if (kargs->bootinfo == 0) {
if ((kargs->bootflags & KARGS_FLAGS_CD) != 0) {
/* we are booting from a CD with cdboot */
new_currdev.d_dev = &bioscd;
new_currdev.d_unit = bc_bios2unit(initial_bootdev);
} else if ((kargs->bootflags & KARGS_FLAGS_PXE) != 0) {
/* we are booting from pxeldr */
new_currdev.d_dev = &pxedisk;
new_currdev.d_unit = 0;
} else {
/* we don't know what our boot device is */
new_currdev.d_kind.biosdisk.slice = -1;
new_currdev.d_kind.biosdisk.partition = 0;
biosdev = -1;
}
#ifdef LOADER_ZFS_SUPPORT
} else if ((kargs->bootflags & KARGS_FLAGS_ZFS) != 0) {
zargs = NULL;
/* check for new style extended argument */
if ((kargs->bootflags & KARGS_FLAGS_EXTARG) != 0)
zargs = (struct zfs_boot_args *)(kargs + 1);
if (zargs != NULL &&
zargs->size >= offsetof(struct zfs_boot_args, primary_pool)) {
/* sufficient data is provided */
new_currdev.d_kind.zfs.pool_guid = zargs->pool;
new_currdev.d_kind.zfs.root_guid = zargs->root;
if (zargs->size >= sizeof(*zargs) && zargs->primary_vdev != 0) {
sprintf(buf, "%llu", zargs->primary_pool);
setenv("vfs.zfs.boot.primary_pool", buf, 1);
sprintf(buf, "%llu", zargs->primary_vdev);
setenv("vfs.zfs.boot.primary_vdev", buf, 1);
}
} else {
/* old style zfsboot block */
new_currdev.d_kind.zfs.pool_guid = kargs->zfspool;
new_currdev.d_kind.zfs.root_guid = 0;
}
new_currdev.d_dev = &zfs_dev;
#endif
} else if ((initial_bootdev & B_MAGICMASK) != B_DEVMAGIC) {
/* The passed-in boot device is bad */
new_currdev.d_kind.biosdisk.slice = -1;
new_currdev.d_kind.biosdisk.partition = 0;
biosdev = -1;
} else {
new_currdev.d_kind.biosdisk.slice = B_SLICE(initial_bootdev) - 1;
new_currdev.d_kind.biosdisk.partition = B_PARTITION(initial_bootdev);
biosdev = initial_bootinfo->bi_bios_dev;
/*
* If we are booted by an old bootstrap, we have to guess at the BIOS
* unit number. We will lose if there is more than one disk type
* and we are not booting from the lowest-numbered disk type
* (ie. SCSI when IDE also exists).
*/
if ((biosdev == 0) && (B_TYPE(initial_bootdev) != 2)) /* biosdev doesn't match major */
biosdev = 0x80 + B_UNIT(initial_bootdev); /* assume harddisk */
}
new_currdev.d_type = new_currdev.d_dev->dv_type;
/*
* If we are booting off of a BIOS disk and we didn't succeed in determining
* which one we booted off of, just use disk0: as a reasonable default.
*/
if ((new_currdev.d_type == biosdisk.dv_type) &&
((new_currdev.d_unit = bd_bios2unit(biosdev)) == -1)) {
printf("Can't work out which disk we are booting from.\n"
"Guessed BIOS device 0x%x not found by probes, defaulting to disk0:\n", biosdev);
new_currdev.d_unit = 0;
}
#ifdef LOADER_ZFS_SUPPORT
if (new_currdev.d_type == DEVT_ZFS)
init_zfs_bootenv(zfs_fmtdev(&new_currdev));
#endif
env_setenv("currdev", EV_VOLATILE, i386_fmtdev(&new_currdev),
i386_setcurrdev, env_nounset);
env_setenv("loaddev", EV_VOLATILE, i386_fmtdev(&new_currdev), env_noset,
env_nounset);
}
COMMAND_SET(reboot, "reboot", "reboot the system", command_reboot);
static int
command_reboot(int argc, char *argv[])
{
int i;
for (i = 0; devsw[i] != NULL; ++i)
if (devsw[i]->dv_cleanup != NULL)
(devsw[i]->dv_cleanup)();
printf("Rebooting...\n");
delay(1000000);
__exit(0);
}
/* provide this for panic, as it's not in the startup code */
void
exit(int code)
{
__exit(code);
}
COMMAND_SET(heap, "heap", "show heap usage", command_heap);
static int
command_heap(int argc, char *argv[])
{
mallocstats();
printf("heap base at %p, top at %p, upper limit at %p\n", heap_bottom,
sbrk(0), heap_top);
return(CMD_OK);
}
#ifdef LOADER_ZFS_SUPPORT
COMMAND_SET(lszfs, "lszfs", "list child datasets of a zfs dataset",
command_lszfs);
static int
command_lszfs(int argc, char *argv[])
{
int err;
if (argc != 2) {
command_errmsg = "wrong number of arguments";
return (CMD_ERROR);
}
err = zfs_list(argv[1]);
if (err != 0) {
command_errmsg = strerror(err);
return (CMD_ERROR);
}
return (CMD_OK);
}
COMMAND_SET(reloadbe, "reloadbe", "refresh the list of ZFS Boot Environments",
command_reloadbe);
static int
command_reloadbe(int argc, char *argv[])
{
int err;
char *root;
if (argc > 2) {
command_errmsg = "wrong number of arguments";
return (CMD_ERROR);
}
if (argc == 2) {
err = zfs_bootenv(argv[1]);
} else {
root = getenv("zfs_be_root");
if (root == NULL) {
/* There does not appear to be a ZFS pool here, exit without error */
return (CMD_OK);
}
err = zfs_bootenv(getenv("zfs_be_root"));
}
if (err != 0) {
command_errmsg = strerror(err);
return (CMD_ERROR);
}
return (CMD_OK);
}
#endif
/* ISA bus access functions for PnP. */
static int
isa_inb(int port)
{
return (inb(port));
}
static void
isa_outb(int port, int value)
{
outb(port, value);
}
#ifdef LOADER_ZFS_SUPPORT
static void
i386_zfs_probe(void)
{
char devname[32];
int unit;
/*
* Open all the disks we can find and see if we can reconstruct
* ZFS pools from them.
*/
for (unit = 0; unit < MAXBDDEV; unit++) {
if (bd_unit2bios(unit) == -1)
break;
sprintf(devname, "disk%d:", unit);
zfs_probe_dev(devname, NULL);
}
}
#endif