108a454a46
Modern bootloaders leverage data stored in the root filesystem to enable some of their powerful features. GRUB specifically has a grubenv file which can store large amounts of configuration data that can be read and written at boot time and during normal operation. This allows sysadmins to configure useful features like automated failover after failed boot attempts. Unfortunately, due to the Copy-on-Write nature of ZFS, the standard behavior of these tools cannot handle writing to ZFS files safely at boot time. We need an alternative way to store data that allows the bootloader to make changes to the data. This work is very similar to work that was done on Illumos to enable similar functionality in the FreeBSD bootloader. This patch is different in that the data being stored is a raw grubenv file; this file can store arbitrary variables and values, and the scripting provided by grub is powerful enough that special structures are not required to implement advanced behavior. We repurpose the second padding area in each label to store the grubenv file, protected by an embedded checksum. We add two ioctls to get and set this data, and libzfs_core and libzfs functions to access them more easily. There are no direct command line interfaces to these functions; these will be added directly to the bootloader utilities. Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com> Reviewed-by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Paul Dagnelie <pcd@delphix.com> Closes #10009
145 lines
5.1 KiB
C
145 lines
5.1 KiB
C
/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License (the "License").
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* You may not use this file except in compliance with the License.
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*
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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* or http://www.opensolaris.org/os/licensing.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*/
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/*
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* Copyright (c) 2012, 2020 by Delphix. All rights reserved.
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* Copyright (c) 2017 Datto Inc.
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* Copyright 2017 RackTop Systems.
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* Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
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*/
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#ifndef _LIBZFS_CORE_H
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#define _LIBZFS_CORE_H
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#include <libnvpair.h>
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#include <sys/param.h>
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#include <sys/types.h>
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#include <sys/fs/zfs.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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int libzfs_core_init(void);
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void libzfs_core_fini(void);
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/*
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* NB: this type should be kept binary compatible with dmu_objset_type_t.
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*/
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enum lzc_dataset_type {
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LZC_DATSET_TYPE_ZFS = 2,
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LZC_DATSET_TYPE_ZVOL
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};
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int lzc_snapshot(nvlist_t *, nvlist_t *, nvlist_t **);
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int lzc_create(const char *, enum lzc_dataset_type, nvlist_t *, uint8_t *,
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uint_t);
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int lzc_clone(const char *, const char *, nvlist_t *);
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int lzc_promote(const char *, char *, int);
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int lzc_destroy_snaps(nvlist_t *, boolean_t, nvlist_t **);
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int lzc_bookmark(nvlist_t *, nvlist_t **);
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int lzc_get_bookmarks(const char *, nvlist_t *, nvlist_t **);
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int lzc_get_bookmark_props(const char *, nvlist_t **);
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int lzc_destroy_bookmarks(nvlist_t *, nvlist_t **);
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int lzc_load_key(const char *, boolean_t, uint8_t *, uint_t);
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int lzc_unload_key(const char *);
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int lzc_change_key(const char *, uint64_t, nvlist_t *, uint8_t *, uint_t);
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int lzc_initialize(const char *, pool_initialize_func_t, nvlist_t *,
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nvlist_t **);
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int lzc_trim(const char *, pool_trim_func_t, uint64_t, boolean_t,
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nvlist_t *, nvlist_t **);
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int lzc_redact(const char *, const char *, nvlist_t *);
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int lzc_snaprange_space(const char *, const char *, uint64_t *);
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int lzc_hold(nvlist_t *, int, nvlist_t **);
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int lzc_release(nvlist_t *, nvlist_t **);
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int lzc_get_holds(const char *, nvlist_t **);
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enum lzc_send_flags {
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LZC_SEND_FLAG_EMBED_DATA = 1 << 0,
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LZC_SEND_FLAG_LARGE_BLOCK = 1 << 1,
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LZC_SEND_FLAG_COMPRESS = 1 << 2,
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LZC_SEND_FLAG_RAW = 1 << 3,
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LZC_SEND_FLAG_SAVED = 1 << 4,
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};
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int lzc_send(const char *, const char *, int, enum lzc_send_flags);
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int lzc_send_resume(const char *, const char *, int,
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enum lzc_send_flags, uint64_t, uint64_t);
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int lzc_send_space(const char *, const char *, enum lzc_send_flags, uint64_t *);
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struct dmu_replay_record;
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int lzc_send_redacted(const char *, const char *, int, enum lzc_send_flags,
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const char *);
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int lzc_send_resume_redacted(const char *, const char *, int,
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enum lzc_send_flags, uint64_t, uint64_t, const char *);
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int lzc_receive(const char *, nvlist_t *, const char *, boolean_t, boolean_t,
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int);
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int lzc_receive_resumable(const char *, nvlist_t *, const char *, boolean_t,
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boolean_t, int);
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int lzc_receive_with_header(const char *, nvlist_t *, const char *, boolean_t,
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boolean_t, boolean_t, int, const struct dmu_replay_record *);
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int lzc_receive_one(const char *, nvlist_t *, const char *, boolean_t,
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boolean_t, boolean_t, int, const struct dmu_replay_record *, int,
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uint64_t *, uint64_t *, uint64_t *, nvlist_t **);
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int lzc_receive_with_cmdprops(const char *, nvlist_t *, nvlist_t *,
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uint8_t *, uint_t, const char *, boolean_t, boolean_t, boolean_t, int,
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const struct dmu_replay_record *, int, uint64_t *, uint64_t *,
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uint64_t *, nvlist_t **);
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int lzc_send_space(const char *, const char *, enum lzc_send_flags, uint64_t *);
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int lzc_send_space_resume_redacted(const char *, const char *,
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enum lzc_send_flags, uint64_t, uint64_t, uint64_t, const char *,
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int, uint64_t *);
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uint64_t lzc_send_progress(int);
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boolean_t lzc_exists(const char *);
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int lzc_rollback(const char *, char *, int);
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int lzc_rollback_to(const char *, const char *);
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int lzc_rename(const char *, const char *);
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int lzc_destroy(const char *);
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int lzc_channel_program(const char *, const char *, uint64_t,
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uint64_t, nvlist_t *, nvlist_t **);
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int lzc_channel_program_nosync(const char *, const char *, uint64_t,
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uint64_t, nvlist_t *, nvlist_t **);
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int lzc_sync(const char *, nvlist_t *, nvlist_t **);
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int lzc_reopen(const char *, boolean_t);
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int lzc_pool_checkpoint(const char *);
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int lzc_pool_checkpoint_discard(const char *);
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int lzc_wait(const char *, zpool_wait_activity_t, boolean_t *);
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int lzc_wait_tag(const char *, zpool_wait_activity_t, uint64_t, boolean_t *);
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int lzc_wait_fs(const char *, zfs_wait_activity_t, boolean_t *);
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int lzc_set_bootenv(const char *, const char *);
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int lzc_get_bootenv(const char *, nvlist_t **);
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#ifdef __cplusplus
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}
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#endif
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#endif /* _LIBZFS_CORE_H */
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