mirror_zfs/include/zfeature_common.h
Rob Norris 224393a321
feature: large_microzap
In a4b21eadec we added the zap_micro_max_size tuneable to raise the size
at which "micro" (single-block) ZAPs are upgraded to "fat" (multi-block)
ZAPs. Before this, a microZAP was limited to 128KiB, which was the old
largest block size. The side effect of raising the max size past 128KiB
is that it be stored in a large block, requiring the large_blocks
feature.

Unfortunately, this means that a backup stream created without the
--large-block (-L) flag to zfs send would split the microZAP block into
smaller blocks and send those, as is normal behaviour for large blocks.
This would be received correctly, but since microZAPs are limited to the
first block in the object by definition, the entries in the later blocks
would be inaccessible. For directory ZAPs, this gives the appearance of
files being lost.

This commit adds a feature flag, large_microzap, that must be enabled
for microZAPs to grow beyond 128KiB, and which will be activated the
first time that occurs. This feature is later checked when generating
the stream and if active, the send operation will abort unless
--large-block has also been requested.

Changing the limit still requires zap_micro_max_size to be changed. The
state of this flag effectively sets the upper value for this tuneable,
that is, if the feature is disabled, the tuneable will be clamped to
128KiB.

A stream flag is also added to ensure that the receiver also activates
its own feature flag upon receiving the stream. This is not strictly
necessary to _use_ the received microZAP, since it doesn't care how
large its block is, but it is required to send the microZAP object on,
otherwise the original problem occurs again.

Because it's difficult to reliably distinguish a microZAP from a fatZAP
from outside the ZAP code, and because it seems unlikely that most
users are affected (a fairly niche tuneable combined with what should be
an uncommon use of send), and for the sake of expediency, this change
activates the feature the first time a microZAP grows to use a large
block, and is never deactivated after that. This can be improved in the
future.

This commit changes nothing for existing pools that already have large
microZAPs. The feature will not be retroactively applied, but will be
activated the next time a microZAP grows past the limit.

Don't use large_blocks feature for enable/disable tests.  The
large_microzap depends on large_blocks, so it gets enabled as a
dependency, breaking the test. Instead use feature "longname", which has
the exact same feature characteristics.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #16593
2024-10-02 20:47:11 -07:00

147 lines
4.4 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
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*
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* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2011, 2018 by Delphix. All rights reserved.
* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
* Copyright (c) 2013, Joyent, Inc. All rights reserved.
* Copyright (c) 2017, Intel Corporation.
* Copyright (c) 2024, Klara, Inc.
*/
#ifndef _ZFEATURE_COMMON_H
#define _ZFEATURE_COMMON_H extern __attribute__((visibility("default")))
#include <sys/fs/zfs.h>
#include <sys/inttypes.h>
#include <sys/types.h>
#ifdef __cplusplus
extern "C" {
#endif
struct zfeature_info;
typedef enum spa_feature {
SPA_FEATURE_NONE = -1,
SPA_FEATURE_ASYNC_DESTROY,
SPA_FEATURE_EMPTY_BPOBJ,
SPA_FEATURE_LZ4_COMPRESS,
SPA_FEATURE_MULTI_VDEV_CRASH_DUMP,
SPA_FEATURE_SPACEMAP_HISTOGRAM,
SPA_FEATURE_ENABLED_TXG,
SPA_FEATURE_HOLE_BIRTH,
SPA_FEATURE_EXTENSIBLE_DATASET,
SPA_FEATURE_EMBEDDED_DATA,
SPA_FEATURE_BOOKMARKS,
SPA_FEATURE_FS_SS_LIMIT,
SPA_FEATURE_LARGE_BLOCKS,
SPA_FEATURE_LARGE_DNODE,
SPA_FEATURE_SHA512,
SPA_FEATURE_SKEIN,
SPA_FEATURE_EDONR,
SPA_FEATURE_USEROBJ_ACCOUNTING,
SPA_FEATURE_ENCRYPTION,
SPA_FEATURE_PROJECT_QUOTA,
SPA_FEATURE_DEVICE_REMOVAL,
SPA_FEATURE_OBSOLETE_COUNTS,
SPA_FEATURE_POOL_CHECKPOINT,
SPA_FEATURE_SPACEMAP_V2,
SPA_FEATURE_ALLOCATION_CLASSES,
SPA_FEATURE_RESILVER_DEFER,
SPA_FEATURE_BOOKMARK_V2,
SPA_FEATURE_REDACTION_BOOKMARKS,
SPA_FEATURE_REDACTED_DATASETS,
SPA_FEATURE_BOOKMARK_WRITTEN,
SPA_FEATURE_LOG_SPACEMAP,
SPA_FEATURE_LIVELIST,
SPA_FEATURE_DEVICE_REBUILD,
SPA_FEATURE_ZSTD_COMPRESS,
SPA_FEATURE_DRAID,
SPA_FEATURE_ZILSAXATTR,
SPA_FEATURE_HEAD_ERRLOG,
SPA_FEATURE_BLAKE3,
SPA_FEATURE_BLOCK_CLONING,
SPA_FEATURE_AVZ_V2,
SPA_FEATURE_REDACTION_LIST_SPILL,
SPA_FEATURE_RAIDZ_EXPANSION,
SPA_FEATURE_FAST_DEDUP,
SPA_FEATURE_LONGNAME,
SPA_FEATURE_LARGE_MICROZAP,
SPA_FEATURES
} spa_feature_t;
#define SPA_FEATURE_DISABLED (-1ULL)
typedef enum zfeature_flags {
/* Can open pool readonly even if this feature is not supported. */
ZFEATURE_FLAG_READONLY_COMPAT = (1 << 0),
/*
* Is this feature necessary to load the pool? i.e. do we need this
* feature to read the full feature list out of the MOS?
*/
ZFEATURE_FLAG_MOS = (1 << 1),
/* Activate this feature at the same time it is enabled. */
ZFEATURE_FLAG_ACTIVATE_ON_ENABLE = (1 << 2),
/* Each dataset has a field set if it has ever used this feature. */
ZFEATURE_FLAG_PER_DATASET = (1 << 3)
} zfeature_flags_t;
typedef enum zfeature_type {
ZFEATURE_TYPE_BOOLEAN,
ZFEATURE_TYPE_UINT64_ARRAY,
ZFEATURE_NUM_TYPES
} zfeature_type_t;
typedef struct zfeature_info {
spa_feature_t fi_feature;
const char *fi_uname; /* User-facing feature name */
const char *fi_guid; /* On-disk feature identifier */
const char *fi_desc; /* Feature description */
zfeature_flags_t fi_flags;
boolean_t fi_zfs_mod_supported; /* supported by running zfs module */
zfeature_type_t fi_type; /* Only relevant for PER_DATASET features */
/* array of dependencies, terminated by SPA_FEATURE_NONE */
const spa_feature_t *fi_depends;
} zfeature_info_t;
typedef int (zfeature_func_t)(zfeature_info_t *, void *);
#define ZFS_FEATURE_DEBUG
_ZFEATURE_COMMON_H zfeature_info_t spa_feature_table[SPA_FEATURES];
_ZFEATURE_COMMON_H boolean_t zfeature_checks_disable;
_ZFEATURE_COMMON_H boolean_t zfeature_is_valid_guid(const char *);
_ZFEATURE_COMMON_H boolean_t zfeature_is_supported(const char *);
_ZFEATURE_COMMON_H int zfeature_lookup_guid(const char *, spa_feature_t *);
_ZFEATURE_COMMON_H int zfeature_lookup_name(const char *, spa_feature_t *);
_ZFEATURE_COMMON_H boolean_t zfeature_depends_on(spa_feature_t, spa_feature_t);
_ZFEATURE_COMMON_H void zpool_feature_init(void);
#ifdef __cplusplus
}
#endif
#endif /* _ZFEATURE_COMMON_H */