zhack: Add repair label option

In case if all label checksums will be invalid on any vdev, the pool
will become unimportable. The zhack with newly added cli options could
be used to restore label checksums and make pool importable again.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Fedor Uporov <fuporov.vstack@gmail.com>
Closes #2510
Closes #12686
This commit is contained in:
Fedor Uporov 2021-11-11 11:26:18 -08:00 committed by GitHub
parent 637771a066
commit d04b5c9e87
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
7 changed files with 252 additions and 1 deletions

View File

@ -33,6 +33,7 @@
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <ctype.h> #include <ctype.h>
#include <sys/stat.h>
#include <sys/zfs_context.h> #include <sys/zfs_context.h>
#include <sys/spa.h> #include <sys/spa.h>
#include <sys/spa_impl.h> #include <sys/spa_impl.h>
@ -41,6 +42,7 @@
#include <sys/zfs_znode.h> #include <sys/zfs_znode.h>
#include <sys/dsl_synctask.h> #include <sys/dsl_synctask.h>
#include <sys/vdev.h> #include <sys/vdev.h>
#include <sys/vdev_impl.h>
#include <sys/fs/zfs.h> #include <sys/fs/zfs.h>
#include <sys/dmu_objset.h> #include <sys/dmu_objset.h>
#include <sys/dsl_pool.h> #include <sys/dsl_pool.h>
@ -76,7 +78,12 @@ usage(void)
" -d decrease instead of increase the refcount\n" " -d decrease instead of increase the refcount\n"
" -m add the feature to the label if increasing refcount\n" " -m add the feature to the label if increasing refcount\n"
"\n" "\n"
" <feature> : should be a feature guid\n"); " <feature> : should be a feature guid\n"
"\n"
" label repair <device>\n"
" repair corrupted label checksums\n"
"\n"
" <device> : path to vdev\n");
exit(1); exit(1);
} }
@ -471,6 +478,166 @@ zhack_do_feature(int argc, char **argv)
return (0); return (0);
} }
static int
zhack_repair_label_cksum(int argc, char **argv)
{
zio_checksum_info_t *ci = &zio_checksum_table[ZIO_CHECKSUM_LABEL];
const char *cfg_keys[] = { ZPOOL_CONFIG_VERSION,
ZPOOL_CONFIG_POOL_STATE, ZPOOL_CONFIG_GUID };
boolean_t labels_repaired[VDEV_LABELS];
boolean_t repaired = B_FALSE;
vdev_label_t labels[VDEV_LABELS];
struct stat st;
int fd;
bzero(labels_repaired, sizeof (labels_repaired));
bzero(labels, sizeof (labels));
abd_init();
argc -= 1;
argv += 1;
if (argc < 1) {
(void) fprintf(stderr, "error: missing device\n");
usage();
}
if ((fd = open(argv[0], O_RDWR)) == -1)
fatal(NULL, FTAG, "cannot open '%s': %s", argv[0],
strerror(errno));
if (stat(argv[0], &st) != 0)
fatal(NULL, FTAG, "cannot stat '%s': %s", argv[0],
strerror(errno));
for (int l = 0; l < VDEV_LABELS; l++) {
uint64_t label_offset, offset;
zio_cksum_t expected_cksum;
zio_cksum_t actual_cksum;
zio_cksum_t verifier;
zio_eck_t *eck;
nvlist_t *cfg;
int byteswap;
uint64_t val;
ssize_t err;
vdev_label_t *vl = &labels[l];
label_offset = vdev_label_offset(st.st_size, l, 0);
err = pread64(fd, vl, sizeof (vdev_label_t), label_offset);
if (err == -1) {
(void) fprintf(stderr, "error: cannot read "
"label %d: %s\n", l, strerror(errno));
continue;
} else if (err != sizeof (vdev_label_t)) {
(void) fprintf(stderr, "error: bad label %d read size "
"\n", l);
continue;
}
err = nvlist_unpack(vl->vl_vdev_phys.vp_nvlist,
VDEV_PHYS_SIZE - sizeof (zio_eck_t), &cfg, 0);
if (err) {
(void) fprintf(stderr, "error: cannot unpack nvlist "
"label %d\n", l);
continue;
}
for (int i = 0; i < ARRAY_SIZE(cfg_keys); i++) {
err = nvlist_lookup_uint64(cfg, cfg_keys[i], &val);
if (err) {
(void) fprintf(stderr, "error: label %d: "
"cannot find nvlist key %s\n",
l, cfg_keys[i]);
continue;
}
}
void *data = (char *)vl + offsetof(vdev_label_t, vl_vdev_phys);
eck = (zio_eck_t *)((char *)(data) + VDEV_PHYS_SIZE) - 1;
offset = label_offset + offsetof(vdev_label_t, vl_vdev_phys);
ZIO_SET_CHECKSUM(&verifier, offset, 0, 0, 0);
byteswap = (eck->zec_magic == BSWAP_64(ZEC_MAGIC));
if (byteswap)
byteswap_uint64_array(&verifier, sizeof (zio_cksum_t));
expected_cksum = eck->zec_cksum;
eck->zec_cksum = verifier;
abd_t *abd = abd_get_from_buf(data, VDEV_PHYS_SIZE);
ci->ci_func[byteswap](abd, VDEV_PHYS_SIZE, NULL, &actual_cksum);
abd_free(abd);
if (byteswap)
byteswap_uint64_array(&expected_cksum,
sizeof (zio_cksum_t));
if (ZIO_CHECKSUM_EQUAL(actual_cksum, expected_cksum))
continue;
eck->zec_cksum = actual_cksum;
err = pwrite64(fd, data, VDEV_PHYS_SIZE, offset);
if (err == -1) {
(void) fprintf(stderr, "error: cannot write "
"label %d: %s\n", l, strerror(errno));
continue;
} else if (err != VDEV_PHYS_SIZE) {
(void) fprintf(stderr, "error: bad write size "
"label %d\n", l);
continue;
}
fsync(fd);
labels_repaired[l] = B_TRUE;
}
close(fd);
abd_fini();
for (int l = 0; l < VDEV_LABELS; l++) {
(void) printf("label %d: %s\n", l,
labels_repaired[l] ? "repaired" : "skipped");
repaired |= labels_repaired[l];
}
if (repaired)
return (0);
return (1);
}
static int
zhack_do_label(int argc, char **argv)
{
char *subcommand;
int err;
argc--;
argv++;
if (argc == 0) {
(void) fprintf(stderr,
"error: no label operation specified\n");
usage();
}
subcommand = argv[0];
if (strcmp(subcommand, "repair") == 0) {
err = zhack_repair_label_cksum(argc, argv);
} else {
(void) fprintf(stderr, "error: unknown subcommand: %s\n",
subcommand);
usage();
}
return (err);
}
#define MAX_NUM_PATHS 1024 #define MAX_NUM_PATHS 1024
int int
@ -516,6 +683,8 @@ main(int argc, char **argv)
if (strcmp(subcommand, "feature") == 0) { if (strcmp(subcommand, "feature") == 0) {
rv = zhack_do_feature(argc, argv); rv = zhack_do_feature(argc, argv);
} else if (strcmp(subcommand, "label") == 0) {
return (zhack_do_label(argc, argv));
} else { } else {
(void) fprintf(stderr, "error: unknown subcommand: %s\n", (void) fprintf(stderr, "error: unknown subcommand: %s\n",
subcommand); subcommand);

View File

@ -288,6 +288,7 @@ AC_CONFIG_FILES([
tests/zfs-tests/tests/functional/cli_root/zfs_unshare/Makefile tests/zfs-tests/tests/functional/cli_root/zfs_unshare/Makefile
tests/zfs-tests/tests/functional/cli_root/zfs_upgrade/Makefile tests/zfs-tests/tests/functional/cli_root/zfs_upgrade/Makefile
tests/zfs-tests/tests/functional/cli_root/zfs_wait/Makefile tests/zfs-tests/tests/functional/cli_root/zfs_wait/Makefile
tests/zfs-tests/tests/functional/cli_root/zhack/Makefile
tests/zfs-tests/tests/functional/cli_root/zpool/Makefile tests/zfs-tests/tests/functional/cli_root/zpool/Makefile
tests/zfs-tests/tests/functional/cli_root/zpool_add/Makefile tests/zfs-tests/tests/functional/cli_root/zpool_add/Makefile
tests/zfs-tests/tests/functional/cli_root/zpool_attach/Makefile tests/zfs-tests/tests/functional/cli_root/zpool_attach/Makefile

View File

@ -94,6 +94,13 @@ The
flag indicates that the flag indicates that the
.Ar guid .Ar guid
feature is now required to read the pool MOS. feature is now required to read the pool MOS.
.
.It Xo
.Nm zhack
.Cm label repair
.Ar device
.Xc
Repair corrupted labels by rewriting the checksum using the presumed valid contents of the label.
.El .El
. .
.Sh GLOBAL OPTIONS .Sh GLOBAL OPTIONS

View File

@ -317,6 +317,12 @@ tags = ['functional', 'cli_root', 'zfs_upgrade']
tests = ['zfs_wait_deleteq'] tests = ['zfs_wait_deleteq']
tags = ['functional', 'cli_root', 'zfs_wait'] tags = ['functional', 'cli_root', 'zfs_wait']
[tests/functional/cli_root/zhack]
tests = ['zhack_label_checksum']
pre =
post =
tags = ['functional', 'cli_root', 'zhack']
[tests/functional/cli_root/zpool] [tests/functional/cli_root/zpool]
tests = ['zpool_001_neg', 'zpool_002_pos', 'zpool_003_pos', 'zpool_colors'] tests = ['zpool_001_neg', 'zpool_002_pos', 'zpool_003_pos', 'zpool_colors']
tags = ['functional', 'cli_root', 'zpool'] tags = ['functional', 'cli_root', 'zpool']

View File

@ -35,6 +35,7 @@ SUBDIRS = \
zfs_unshare \ zfs_unshare \
zfs_upgrade \ zfs_upgrade \
zfs_wait \ zfs_wait \
zhack \
zpool \ zpool \
zpool_add \ zpool_add \
zpool_attach \ zpool_attach \

View File

@ -0,0 +1,3 @@
pkgdatadir = $(datadir)/@PACKAGE@/zfs-tests/tests/functional/cli_root/zhack
dist_pkgdata_SCRIPTS = \
zhack_label_checksum.ksh

View File

@ -0,0 +1,64 @@
#!/bin/ksh
#
# This file and its contents are supplied under the terms of the
# Common Development and Distribution License ("CDDL"), version 1.0.
# You may only use this file in accordance with the terms of version
# 1.0 of the CDDL.
#
# A full copy of the text of the CDDL should have accompanied this
# source. A copy of the CDDL is also available via the Internet at
# http://www.illumos.org/license/CDDL.
#
#
# Copyright (c) 2021 by vStack. All rights reserved.
#
. $STF_SUITE/include/libtest.shlib
. $STF_SUITE/include/blkdev.shlib
#
# Description:
# zhack label repair <vdev> will calculate and rewrite label checksum if invalid
#
# Strategy:
# 1. Create pool with some number of vdevs and export it
# 2. Corrupt all labels checksums
# 3. Check that pool cannot be imported
# 4. Use zhack to repair labels checksums
# 5. Check that pool can be imported
#
log_assert "Verify zhack label repair <vdev> will repair labels checksums"
log_onexit cleanup
VIRTUAL_DISK=$TEST_BASE_DIR/disk
function cleanup
{
poolexists $TESTPOOL && destroy_pool $TESTPOOL
[[ -f $VIRTUAL_DISK ]] && log_must rm $VIRTUAL_DISK
}
log_must truncate -s $(($MINVDEVSIZE * 8)) $VIRTUAL_DISK
log_must zpool create $TESTPOOL $VIRTUAL_DISK
log_must zpool export $TESTPOOL
log_mustnot zhack label repair $VIRTUAL_DISK
corrupt_label_checksum 0 $VIRTUAL_DISK
corrupt_label_checksum 1 $VIRTUAL_DISK
corrupt_label_checksum 2 $VIRTUAL_DISK
corrupt_label_checksum 3 $VIRTUAL_DISK
log_mustnot zpool import $TESTPOOL -d $TEST_BASE_DIR
log_must zhack label repair $VIRTUAL_DISK
log_must zpool import $TESTPOOL -d $TEST_BASE_DIR
cleanup
log_pass "zhack label repair works correctly."