2a8ba608d3
Remove the ASSERTV macro and handle suppressing unused compiler warnings for variables only in ASSERTs using the __attribute__((unused)) compiler annotation. The annotation is understood by both gcc and clang. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Jorgen Lundman <lundman@lundman.net> Signed-off-by: Matt Macy <mmacy@FreeBSD.org> Closes #9671
1891 lines
60 KiB
C
1891 lines
60 KiB
C
/*
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* CDDL HEADER START
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*
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* This file and its contents are supplied under the terms of the
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* Common Development and Distribution License ("CDDL"), version 1.0.
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* You may only use this file in accordance with the terms of version
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* 1.0 of the CDDL.
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*
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* A full copy of the text of the CDDL should have accompanied this
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* source. A copy of the CDDL is also available via the Internet at
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* http://www.illumos.org/license/CDDL.
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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) 2014, 2017 by Delphix. All rights reserved.
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* Copyright (c) 2019, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
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* Copyright (c) 2014, 2019 by Delphix. All rights reserved.
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*/
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#include <sys/zfs_context.h>
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#include <sys/spa.h>
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#include <sys/spa_impl.h>
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#include <sys/vdev_impl.h>
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#include <sys/fs/zfs.h>
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#include <sys/zio.h>
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#include <sys/zio_checksum.h>
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#include <sys/metaslab.h>
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#include <sys/refcount.h>
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#include <sys/dmu.h>
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#include <sys/vdev_indirect_mapping.h>
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#include <sys/dmu_tx.h>
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#include <sys/dsl_synctask.h>
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#include <sys/zap.h>
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#include <sys/abd.h>
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#include <sys/zthr.h>
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/*
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* An indirect vdev corresponds to a vdev that has been removed. Since
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* we cannot rewrite block pointers of snapshots, etc., we keep a
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* mapping from old location on the removed device to the new location
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* on another device in the pool and use this mapping whenever we need
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* to access the DVA. Unfortunately, this mapping did not respect
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* logical block boundaries when it was first created, and so a DVA on
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* this indirect vdev may be "split" into multiple sections that each
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* map to a different location. As a consequence, not all DVAs can be
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* translated to an equivalent new DVA. Instead we must provide a
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* "vdev_remap" operation that executes a callback on each contiguous
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* segment of the new location. This function is used in multiple ways:
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*
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* - i/os to this vdev use the callback to determine where the
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* data is now located, and issue child i/os for each segment's new
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* location.
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*
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* - frees and claims to this vdev use the callback to free or claim
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* each mapped segment. (Note that we don't actually need to claim
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* log blocks on indirect vdevs, because we don't allocate to
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* removing vdevs. However, zdb uses zio_claim() for its leak
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* detection.)
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*/
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/*
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* "Big theory statement" for how we mark blocks obsolete.
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*
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* When a block on an indirect vdev is freed or remapped, a section of
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* that vdev's mapping may no longer be referenced (aka "obsolete"). We
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* keep track of how much of each mapping entry is obsolete. When
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* an entry becomes completely obsolete, we can remove it, thus reducing
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* the memory used by the mapping. The complete picture of obsolescence
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* is given by the following data structures, described below:
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* - the entry-specific obsolete count
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* - the vdev-specific obsolete spacemap
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* - the pool-specific obsolete bpobj
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*
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* == On disk data structures used ==
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*
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* We track the obsolete space for the pool using several objects. Each
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* of these objects is created on demand and freed when no longer
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* needed, and is assumed to be empty if it does not exist.
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* SPA_FEATURE_OBSOLETE_COUNTS includes the count of these objects.
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*
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* - Each vic_mapping_object (associated with an indirect vdev) can
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* have a vimp_counts_object. This is an array of uint32_t's
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* with the same number of entries as the vic_mapping_object. When
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* the mapping is condensed, entries from the vic_obsolete_sm_object
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* (see below) are folded into the counts. Therefore, each
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* obsolete_counts entry tells us the number of bytes in the
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* corresponding mapping entry that were not referenced when the
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* mapping was last condensed.
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*
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* - Each indirect or removing vdev can have a vic_obsolete_sm_object.
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* This is a space map containing an alloc entry for every DVA that
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* has been obsoleted since the last time this indirect vdev was
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* condensed. We use this object in order to improve performance
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* when marking a DVA as obsolete. Instead of modifying an arbitrary
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* offset of the vimp_counts_object, we only need to append an entry
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* to the end of this object. When a DVA becomes obsolete, it is
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* added to the obsolete space map. This happens when the DVA is
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* freed, remapped and not referenced by a snapshot, or the last
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* snapshot referencing it is destroyed.
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*
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* - Each dataset can have a ds_remap_deadlist object. This is a
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* deadlist object containing all blocks that were remapped in this
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* dataset but referenced in a previous snapshot. Blocks can *only*
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* appear on this list if they were remapped (dsl_dataset_block_remapped);
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* blocks that were killed in a head dataset are put on the normal
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* ds_deadlist and marked obsolete when they are freed.
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*
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* - The pool can have a dp_obsolete_bpobj. This is a list of blocks
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* in the pool that need to be marked obsolete. When a snapshot is
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* destroyed, we move some of the ds_remap_deadlist to the obsolete
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* bpobj (see dsl_destroy_snapshot_handle_remaps()). We then
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* asynchronously process the obsolete bpobj, moving its entries to
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* the specific vdevs' obsolete space maps.
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*
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* == Summary of how we mark blocks as obsolete ==
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*
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* - When freeing a block: if any DVA is on an indirect vdev, append to
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* vic_obsolete_sm_object.
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* - When remapping a block, add dva to ds_remap_deadlist (if prev snap
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* references; otherwise append to vic_obsolete_sm_object).
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* - When freeing a snapshot: move parts of ds_remap_deadlist to
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* dp_obsolete_bpobj (same algorithm as ds_deadlist).
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* - When syncing the spa: process dp_obsolete_bpobj, moving ranges to
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* individual vdev's vic_obsolete_sm_object.
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*/
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/*
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* "Big theory statement" for how we condense indirect vdevs.
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*
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* Condensing an indirect vdev's mapping is the process of determining
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* the precise counts of obsolete space for each mapping entry (by
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* integrating the obsolete spacemap into the obsolete counts) and
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* writing out a new mapping that contains only referenced entries.
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*
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* We condense a vdev when we expect the mapping to shrink (see
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* vdev_indirect_should_condense()), but only perform one condense at a
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* time to limit the memory usage. In addition, we use a separate
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* open-context thread (spa_condense_indirect_thread) to incrementally
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* create the new mapping object in a way that minimizes the impact on
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* the rest of the system.
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*
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* == Generating a new mapping ==
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*
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* To generate a new mapping, we follow these steps:
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*
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* 1. Save the old obsolete space map and create a new mapping object
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* (see spa_condense_indirect_start_sync()). This initializes the
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* spa_condensing_indirect_phys with the "previous obsolete space map",
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* which is now read only. Newly obsolete DVAs will be added to a
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* new (initially empty) obsolete space map, and will not be
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* considered as part of this condense operation.
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*
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* 2. Construct in memory the precise counts of obsolete space for each
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* mapping entry, by incorporating the obsolete space map into the
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* counts. (See vdev_indirect_mapping_load_obsolete_{counts,spacemap}().)
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*
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* 3. Iterate through each mapping entry, writing to the new mapping any
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* entries that are not completely obsolete (i.e. which don't have
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* obsolete count == mapping length). (See
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* spa_condense_indirect_generate_new_mapping().)
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*
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* 4. Destroy the old mapping object and switch over to the new one
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* (spa_condense_indirect_complete_sync).
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*
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* == Restarting from failure ==
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*
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* To restart the condense when we import/open the pool, we must start
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* at the 2nd step above: reconstruct the precise counts in memory,
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* based on the space map + counts. Then in the 3rd step, we start
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* iterating where we left off: at vimp_max_offset of the new mapping
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* object.
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*/
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int zfs_condense_indirect_vdevs_enable = B_TRUE;
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/*
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* Condense if at least this percent of the bytes in the mapping is
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* obsolete. With the default of 25%, the amount of space mapped
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* will be reduced to 1% of its original size after at most 16
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* condenses. Higher values will condense less often (causing less
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* i/o); lower values will reduce the mapping size more quickly.
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*/
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int zfs_indirect_condense_obsolete_pct = 25;
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/*
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* Condense if the obsolete space map takes up more than this amount of
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* space on disk (logically). This limits the amount of disk space
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* consumed by the obsolete space map; the default of 1GB is small enough
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* that we typically don't mind "wasting" it.
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*/
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unsigned long zfs_condense_max_obsolete_bytes = 1024 * 1024 * 1024;
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/*
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* Don't bother condensing if the mapping uses less than this amount of
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* memory. The default of 128KB is considered a "trivial" amount of
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* memory and not worth reducing.
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*/
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unsigned long zfs_condense_min_mapping_bytes = 128 * 1024;
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/*
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* This is used by the test suite so that it can ensure that certain
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* actions happen while in the middle of a condense (which might otherwise
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* complete too quickly). If used to reduce the performance impact of
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* condensing in production, a maximum value of 1 should be sufficient.
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*/
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int zfs_condense_indirect_commit_entry_delay_ms = 0;
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/*
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* If an indirect split block contains more than this many possible unique
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* combinations when being reconstructed, consider it too computationally
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* expensive to check them all. Instead, try at most 100 randomly-selected
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* combinations each time the block is accessed. This allows all segment
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* copies to participate fairly in the reconstruction when all combinations
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* cannot be checked and prevents repeated use of one bad copy.
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*/
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int zfs_reconstruct_indirect_combinations_max = 4096;
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/*
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* Enable to simulate damaged segments and validate reconstruction. This
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* is intentionally not exposed as a module parameter.
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*/
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unsigned long zfs_reconstruct_indirect_damage_fraction = 0;
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/*
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* The indirect_child_t represents the vdev that we will read from, when we
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* need to read all copies of the data (e.g. for scrub or reconstruction).
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* For plain (non-mirror) top-level vdevs (i.e. is_vdev is not a mirror),
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* ic_vdev is the same as is_vdev. However, for mirror top-level vdevs,
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* ic_vdev is a child of the mirror.
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*/
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typedef struct indirect_child {
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abd_t *ic_data;
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vdev_t *ic_vdev;
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/*
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* ic_duplicate is NULL when the ic_data contents are unique, when it
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* is determined to be a duplicate it references the primary child.
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*/
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struct indirect_child *ic_duplicate;
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list_node_t ic_node; /* node on is_unique_child */
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} indirect_child_t;
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/*
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* The indirect_split_t represents one mapped segment of an i/o to the
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* indirect vdev. For non-split (contiguously-mapped) blocks, there will be
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* only one indirect_split_t, with is_split_offset==0 and is_size==io_size.
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* For split blocks, there will be several of these.
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*/
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typedef struct indirect_split {
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list_node_t is_node; /* link on iv_splits */
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/*
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* is_split_offset is the offset into the i/o.
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* This is the sum of the previous splits' is_size's.
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*/
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uint64_t is_split_offset;
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vdev_t *is_vdev; /* top-level vdev */
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uint64_t is_target_offset; /* offset on is_vdev */
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uint64_t is_size;
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int is_children; /* number of entries in is_child[] */
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int is_unique_children; /* number of entries in is_unique_child */
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list_t is_unique_child;
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/*
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* is_good_child is the child that we are currently using to
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* attempt reconstruction.
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*/
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indirect_child_t *is_good_child;
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indirect_child_t is_child[1]; /* variable-length */
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} indirect_split_t;
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/*
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* The indirect_vsd_t is associated with each i/o to the indirect vdev.
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* It is the "Vdev-Specific Data" in the zio_t's io_vsd.
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*/
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typedef struct indirect_vsd {
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boolean_t iv_split_block;
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boolean_t iv_reconstruct;
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uint64_t iv_unique_combinations;
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uint64_t iv_attempts;
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uint64_t iv_attempts_max;
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list_t iv_splits; /* list of indirect_split_t's */
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} indirect_vsd_t;
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static void
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vdev_indirect_map_free(zio_t *zio)
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{
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indirect_vsd_t *iv = zio->io_vsd;
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indirect_split_t *is;
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while ((is = list_head(&iv->iv_splits)) != NULL) {
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for (int c = 0; c < is->is_children; c++) {
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indirect_child_t *ic = &is->is_child[c];
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if (ic->ic_data != NULL)
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abd_free(ic->ic_data);
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}
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list_remove(&iv->iv_splits, is);
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indirect_child_t *ic;
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while ((ic = list_head(&is->is_unique_child)) != NULL)
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list_remove(&is->is_unique_child, ic);
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list_destroy(&is->is_unique_child);
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kmem_free(is,
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offsetof(indirect_split_t, is_child[is->is_children]));
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}
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kmem_free(iv, sizeof (*iv));
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}
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static const zio_vsd_ops_t vdev_indirect_vsd_ops = {
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.vsd_free = vdev_indirect_map_free,
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.vsd_cksum_report = zio_vsd_default_cksum_report
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};
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/*
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* Mark the given offset and size as being obsolete.
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*/
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void
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vdev_indirect_mark_obsolete(vdev_t *vd, uint64_t offset, uint64_t size)
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{
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spa_t *spa = vd->vdev_spa;
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ASSERT3U(vd->vdev_indirect_config.vic_mapping_object, !=, 0);
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ASSERT(vd->vdev_removing || vd->vdev_ops == &vdev_indirect_ops);
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ASSERT(size > 0);
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VERIFY(vdev_indirect_mapping_entry_for_offset(
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vd->vdev_indirect_mapping, offset) != NULL);
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if (spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS)) {
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mutex_enter(&vd->vdev_obsolete_lock);
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range_tree_add(vd->vdev_obsolete_segments, offset, size);
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mutex_exit(&vd->vdev_obsolete_lock);
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vdev_dirty(vd, 0, NULL, spa_syncing_txg(spa));
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}
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}
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/*
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* Mark the DVA vdev_id:offset:size as being obsolete in the given tx. This
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* wrapper is provided because the DMU does not know about vdev_t's and
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* cannot directly call vdev_indirect_mark_obsolete.
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*/
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void
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spa_vdev_indirect_mark_obsolete(spa_t *spa, uint64_t vdev_id, uint64_t offset,
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uint64_t size, dmu_tx_t *tx)
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{
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vdev_t *vd = vdev_lookup_top(spa, vdev_id);
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ASSERT(dmu_tx_is_syncing(tx));
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/* The DMU can only remap indirect vdevs. */
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ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops);
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vdev_indirect_mark_obsolete(vd, offset, size);
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}
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static spa_condensing_indirect_t *
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spa_condensing_indirect_create(spa_t *spa)
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{
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spa_condensing_indirect_phys_t *scip =
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&spa->spa_condensing_indirect_phys;
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spa_condensing_indirect_t *sci = kmem_zalloc(sizeof (*sci), KM_SLEEP);
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objset_t *mos = spa->spa_meta_objset;
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for (int i = 0; i < TXG_SIZE; i++) {
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list_create(&sci->sci_new_mapping_entries[i],
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sizeof (vdev_indirect_mapping_entry_t),
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offsetof(vdev_indirect_mapping_entry_t, vime_node));
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}
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sci->sci_new_mapping =
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vdev_indirect_mapping_open(mos, scip->scip_next_mapping_object);
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return (sci);
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}
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static void
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spa_condensing_indirect_destroy(spa_condensing_indirect_t *sci)
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{
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for (int i = 0; i < TXG_SIZE; i++)
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list_destroy(&sci->sci_new_mapping_entries[i]);
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if (sci->sci_new_mapping != NULL)
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vdev_indirect_mapping_close(sci->sci_new_mapping);
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kmem_free(sci, sizeof (*sci));
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}
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boolean_t
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vdev_indirect_should_condense(vdev_t *vd)
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{
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vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;
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spa_t *spa = vd->vdev_spa;
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ASSERT(dsl_pool_sync_context(spa->spa_dsl_pool));
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if (!zfs_condense_indirect_vdevs_enable)
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return (B_FALSE);
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/*
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* We can only condense one indirect vdev at a time.
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*/
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if (spa->spa_condensing_indirect != NULL)
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return (B_FALSE);
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if (spa_shutting_down(spa))
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return (B_FALSE);
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/*
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* The mapping object size must not change while we are
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* condensing, so we can only condense indirect vdevs
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* (not vdevs that are still in the middle of being removed).
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*/
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if (vd->vdev_ops != &vdev_indirect_ops)
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return (B_FALSE);
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/*
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* If nothing new has been marked obsolete, there is no
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* point in condensing.
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*/
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uint64_t obsolete_sm_obj __maybe_unused;
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ASSERT0(vdev_obsolete_sm_object(vd, &obsolete_sm_obj));
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if (vd->vdev_obsolete_sm == NULL) {
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ASSERT0(obsolete_sm_obj);
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return (B_FALSE);
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}
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ASSERT(vd->vdev_obsolete_sm != NULL);
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ASSERT3U(obsolete_sm_obj, ==, space_map_object(vd->vdev_obsolete_sm));
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uint64_t bytes_mapped = vdev_indirect_mapping_bytes_mapped(vim);
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uint64_t bytes_obsolete = space_map_allocated(vd->vdev_obsolete_sm);
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uint64_t mapping_size = vdev_indirect_mapping_size(vim);
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uint64_t obsolete_sm_size = space_map_length(vd->vdev_obsolete_sm);
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ASSERT3U(bytes_obsolete, <=, bytes_mapped);
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/*
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* If a high percentage of the bytes that are mapped have become
|
|
* obsolete, condense (unless the mapping is already small enough).
|
|
* This has a good chance of reducing the amount of memory used
|
|
* by the mapping.
|
|
*/
|
|
if (bytes_obsolete * 100 / bytes_mapped >=
|
|
zfs_indirect_condense_obsolete_pct &&
|
|
mapping_size > zfs_condense_min_mapping_bytes) {
|
|
zfs_dbgmsg("should condense vdev %llu because obsolete "
|
|
"spacemap covers %d%% of %lluMB mapping",
|
|
(u_longlong_t)vd->vdev_id,
|
|
(int)(bytes_obsolete * 100 / bytes_mapped),
|
|
(u_longlong_t)bytes_mapped / 1024 / 1024);
|
|
return (B_TRUE);
|
|
}
|
|
|
|
/*
|
|
* If the obsolete space map takes up too much space on disk,
|
|
* condense in order to free up this disk space.
|
|
*/
|
|
if (obsolete_sm_size >= zfs_condense_max_obsolete_bytes) {
|
|
zfs_dbgmsg("should condense vdev %llu because obsolete sm "
|
|
"length %lluMB >= max size %lluMB",
|
|
(u_longlong_t)vd->vdev_id,
|
|
(u_longlong_t)obsolete_sm_size / 1024 / 1024,
|
|
(u_longlong_t)zfs_condense_max_obsolete_bytes /
|
|
1024 / 1024);
|
|
return (B_TRUE);
|
|
}
|
|
|
|
return (B_FALSE);
|
|
}
|
|
|
|
/*
|
|
* This sync task completes (finishes) a condense, deleting the old
|
|
* mapping and replacing it with the new one.
|
|
*/
|
|
static void
|
|
spa_condense_indirect_complete_sync(void *arg, dmu_tx_t *tx)
|
|
{
|
|
spa_condensing_indirect_t *sci = arg;
|
|
spa_t *spa = dmu_tx_pool(tx)->dp_spa;
|
|
spa_condensing_indirect_phys_t *scip =
|
|
&spa->spa_condensing_indirect_phys;
|
|
vdev_t *vd = vdev_lookup_top(spa, scip->scip_vdev);
|
|
vdev_indirect_config_t *vic = &vd->vdev_indirect_config;
|
|
objset_t *mos = spa->spa_meta_objset;
|
|
vdev_indirect_mapping_t *old_mapping = vd->vdev_indirect_mapping;
|
|
uint64_t old_count = vdev_indirect_mapping_num_entries(old_mapping);
|
|
uint64_t new_count =
|
|
vdev_indirect_mapping_num_entries(sci->sci_new_mapping);
|
|
|
|
ASSERT(dmu_tx_is_syncing(tx));
|
|
ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops);
|
|
ASSERT3P(sci, ==, spa->spa_condensing_indirect);
|
|
for (int i = 0; i < TXG_SIZE; i++) {
|
|
ASSERT(list_is_empty(&sci->sci_new_mapping_entries[i]));
|
|
}
|
|
ASSERT(vic->vic_mapping_object != 0);
|
|
ASSERT3U(vd->vdev_id, ==, scip->scip_vdev);
|
|
ASSERT(scip->scip_next_mapping_object != 0);
|
|
ASSERT(scip->scip_prev_obsolete_sm_object != 0);
|
|
|
|
/*
|
|
* Reset vdev_indirect_mapping to refer to the new object.
|
|
*/
|
|
rw_enter(&vd->vdev_indirect_rwlock, RW_WRITER);
|
|
vdev_indirect_mapping_close(vd->vdev_indirect_mapping);
|
|
vd->vdev_indirect_mapping = sci->sci_new_mapping;
|
|
rw_exit(&vd->vdev_indirect_rwlock);
|
|
|
|
sci->sci_new_mapping = NULL;
|
|
vdev_indirect_mapping_free(mos, vic->vic_mapping_object, tx);
|
|
vic->vic_mapping_object = scip->scip_next_mapping_object;
|
|
scip->scip_next_mapping_object = 0;
|
|
|
|
space_map_free_obj(mos, scip->scip_prev_obsolete_sm_object, tx);
|
|
spa_feature_decr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx);
|
|
scip->scip_prev_obsolete_sm_object = 0;
|
|
|
|
scip->scip_vdev = 0;
|
|
|
|
VERIFY0(zap_remove(mos, DMU_POOL_DIRECTORY_OBJECT,
|
|
DMU_POOL_CONDENSING_INDIRECT, tx));
|
|
spa_condensing_indirect_destroy(spa->spa_condensing_indirect);
|
|
spa->spa_condensing_indirect = NULL;
|
|
|
|
zfs_dbgmsg("finished condense of vdev %llu in txg %llu: "
|
|
"new mapping object %llu has %llu entries "
|
|
"(was %llu entries)",
|
|
vd->vdev_id, dmu_tx_get_txg(tx), vic->vic_mapping_object,
|
|
new_count, old_count);
|
|
|
|
vdev_config_dirty(spa->spa_root_vdev);
|
|
}
|
|
|
|
/*
|
|
* This sync task appends entries to the new mapping object.
|
|
*/
|
|
static void
|
|
spa_condense_indirect_commit_sync(void *arg, dmu_tx_t *tx)
|
|
{
|
|
spa_condensing_indirect_t *sci = arg;
|
|
uint64_t txg = dmu_tx_get_txg(tx);
|
|
spa_t *spa __maybe_unused = dmu_tx_pool(tx)->dp_spa;
|
|
|
|
ASSERT(dmu_tx_is_syncing(tx));
|
|
ASSERT3P(sci, ==, spa->spa_condensing_indirect);
|
|
|
|
vdev_indirect_mapping_add_entries(sci->sci_new_mapping,
|
|
&sci->sci_new_mapping_entries[txg & TXG_MASK], tx);
|
|
ASSERT(list_is_empty(&sci->sci_new_mapping_entries[txg & TXG_MASK]));
|
|
}
|
|
|
|
/*
|
|
* Open-context function to add one entry to the new mapping. The new
|
|
* entry will be remembered and written from syncing context.
|
|
*/
|
|
static void
|
|
spa_condense_indirect_commit_entry(spa_t *spa,
|
|
vdev_indirect_mapping_entry_phys_t *vimep, uint32_t count)
|
|
{
|
|
spa_condensing_indirect_t *sci = spa->spa_condensing_indirect;
|
|
|
|
ASSERT3U(count, <, DVA_GET_ASIZE(&vimep->vimep_dst));
|
|
|
|
dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
|
|
dmu_tx_hold_space(tx, sizeof (*vimep) + sizeof (count));
|
|
VERIFY0(dmu_tx_assign(tx, TXG_WAIT));
|
|
int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
|
|
|
|
/*
|
|
* If we are the first entry committed this txg, kick off the sync
|
|
* task to write to the MOS on our behalf.
|
|
*/
|
|
if (list_is_empty(&sci->sci_new_mapping_entries[txgoff])) {
|
|
dsl_sync_task_nowait(dmu_tx_pool(tx),
|
|
spa_condense_indirect_commit_sync, sci,
|
|
0, ZFS_SPACE_CHECK_NONE, tx);
|
|
}
|
|
|
|
vdev_indirect_mapping_entry_t *vime =
|
|
kmem_alloc(sizeof (*vime), KM_SLEEP);
|
|
vime->vime_mapping = *vimep;
|
|
vime->vime_obsolete_count = count;
|
|
list_insert_tail(&sci->sci_new_mapping_entries[txgoff], vime);
|
|
|
|
dmu_tx_commit(tx);
|
|
}
|
|
|
|
static void
|
|
spa_condense_indirect_generate_new_mapping(vdev_t *vd,
|
|
uint32_t *obsolete_counts, uint64_t start_index, zthr_t *zthr)
|
|
{
|
|
spa_t *spa = vd->vdev_spa;
|
|
uint64_t mapi = start_index;
|
|
vdev_indirect_mapping_t *old_mapping = vd->vdev_indirect_mapping;
|
|
uint64_t old_num_entries =
|
|
vdev_indirect_mapping_num_entries(old_mapping);
|
|
|
|
ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops);
|
|
ASSERT3U(vd->vdev_id, ==, spa->spa_condensing_indirect_phys.scip_vdev);
|
|
|
|
zfs_dbgmsg("starting condense of vdev %llu from index %llu",
|
|
(u_longlong_t)vd->vdev_id,
|
|
(u_longlong_t)mapi);
|
|
|
|
while (mapi < old_num_entries) {
|
|
|
|
if (zthr_iscancelled(zthr)) {
|
|
zfs_dbgmsg("pausing condense of vdev %llu "
|
|
"at index %llu", (u_longlong_t)vd->vdev_id,
|
|
(u_longlong_t)mapi);
|
|
break;
|
|
}
|
|
|
|
vdev_indirect_mapping_entry_phys_t *entry =
|
|
&old_mapping->vim_entries[mapi];
|
|
uint64_t entry_size = DVA_GET_ASIZE(&entry->vimep_dst);
|
|
ASSERT3U(obsolete_counts[mapi], <=, entry_size);
|
|
if (obsolete_counts[mapi] < entry_size) {
|
|
spa_condense_indirect_commit_entry(spa, entry,
|
|
obsolete_counts[mapi]);
|
|
|
|
/*
|
|
* This delay may be requested for testing, debugging,
|
|
* or performance reasons.
|
|
*/
|
|
hrtime_t now = gethrtime();
|
|
hrtime_t sleep_until = now + MSEC2NSEC(
|
|
zfs_condense_indirect_commit_entry_delay_ms);
|
|
zfs_sleep_until(sleep_until);
|
|
}
|
|
|
|
mapi++;
|
|
}
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static boolean_t
|
|
spa_condense_indirect_thread_check(void *arg, zthr_t *zthr)
|
|
{
|
|
spa_t *spa = arg;
|
|
|
|
return (spa->spa_condensing_indirect != NULL);
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static void
|
|
spa_condense_indirect_thread(void *arg, zthr_t *zthr)
|
|
{
|
|
spa_t *spa = arg;
|
|
vdev_t *vd;
|
|
|
|
ASSERT3P(spa->spa_condensing_indirect, !=, NULL);
|
|
spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
|
|
vd = vdev_lookup_top(spa, spa->spa_condensing_indirect_phys.scip_vdev);
|
|
ASSERT3P(vd, !=, NULL);
|
|
spa_config_exit(spa, SCL_VDEV, FTAG);
|
|
|
|
spa_condensing_indirect_t *sci = spa->spa_condensing_indirect;
|
|
spa_condensing_indirect_phys_t *scip =
|
|
&spa->spa_condensing_indirect_phys;
|
|
uint32_t *counts;
|
|
uint64_t start_index;
|
|
vdev_indirect_mapping_t *old_mapping = vd->vdev_indirect_mapping;
|
|
space_map_t *prev_obsolete_sm = NULL;
|
|
|
|
ASSERT3U(vd->vdev_id, ==, scip->scip_vdev);
|
|
ASSERT(scip->scip_next_mapping_object != 0);
|
|
ASSERT(scip->scip_prev_obsolete_sm_object != 0);
|
|
ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops);
|
|
|
|
for (int i = 0; i < TXG_SIZE; i++) {
|
|
/*
|
|
* The list must start out empty in order for the
|
|
* _commit_sync() sync task to be properly registered
|
|
* on the first call to _commit_entry(); so it's wise
|
|
* to double check and ensure we actually are starting
|
|
* with empty lists.
|
|
*/
|
|
ASSERT(list_is_empty(&sci->sci_new_mapping_entries[i]));
|
|
}
|
|
|
|
VERIFY0(space_map_open(&prev_obsolete_sm, spa->spa_meta_objset,
|
|
scip->scip_prev_obsolete_sm_object, 0, vd->vdev_asize, 0));
|
|
counts = vdev_indirect_mapping_load_obsolete_counts(old_mapping);
|
|
if (prev_obsolete_sm != NULL) {
|
|
vdev_indirect_mapping_load_obsolete_spacemap(old_mapping,
|
|
counts, prev_obsolete_sm);
|
|
}
|
|
space_map_close(prev_obsolete_sm);
|
|
|
|
/*
|
|
* Generate new mapping. Determine what index to continue from
|
|
* based on the max offset that we've already written in the
|
|
* new mapping.
|
|
*/
|
|
uint64_t max_offset =
|
|
vdev_indirect_mapping_max_offset(sci->sci_new_mapping);
|
|
if (max_offset == 0) {
|
|
/* We haven't written anything to the new mapping yet. */
|
|
start_index = 0;
|
|
} else {
|
|
/*
|
|
* Pick up from where we left off. _entry_for_offset()
|
|
* returns a pointer into the vim_entries array. If
|
|
* max_offset is greater than any of the mappings
|
|
* contained in the table NULL will be returned and
|
|
* that indicates we've exhausted our iteration of the
|
|
* old_mapping.
|
|
*/
|
|
|
|
vdev_indirect_mapping_entry_phys_t *entry =
|
|
vdev_indirect_mapping_entry_for_offset_or_next(old_mapping,
|
|
max_offset);
|
|
|
|
if (entry == NULL) {
|
|
/*
|
|
* We've already written the whole new mapping.
|
|
* This special value will cause us to skip the
|
|
* generate_new_mapping step and just do the sync
|
|
* task to complete the condense.
|
|
*/
|
|
start_index = UINT64_MAX;
|
|
} else {
|
|
start_index = entry - old_mapping->vim_entries;
|
|
ASSERT3U(start_index, <,
|
|
vdev_indirect_mapping_num_entries(old_mapping));
|
|
}
|
|
}
|
|
|
|
spa_condense_indirect_generate_new_mapping(vd, counts,
|
|
start_index, zthr);
|
|
|
|
vdev_indirect_mapping_free_obsolete_counts(old_mapping, counts);
|
|
|
|
/*
|
|
* If the zthr has received a cancellation signal while running
|
|
* in generate_new_mapping() or at any point after that, then bail
|
|
* early. We don't want to complete the condense if the spa is
|
|
* shutting down.
|
|
*/
|
|
if (zthr_iscancelled(zthr))
|
|
return;
|
|
|
|
VERIFY0(dsl_sync_task(spa_name(spa), NULL,
|
|
spa_condense_indirect_complete_sync, sci, 0,
|
|
ZFS_SPACE_CHECK_EXTRA_RESERVED));
|
|
}
|
|
|
|
/*
|
|
* Sync task to begin the condensing process.
|
|
*/
|
|
void
|
|
spa_condense_indirect_start_sync(vdev_t *vd, dmu_tx_t *tx)
|
|
{
|
|
spa_t *spa = vd->vdev_spa;
|
|
spa_condensing_indirect_phys_t *scip =
|
|
&spa->spa_condensing_indirect_phys;
|
|
|
|
ASSERT0(scip->scip_next_mapping_object);
|
|
ASSERT0(scip->scip_prev_obsolete_sm_object);
|
|
ASSERT0(scip->scip_vdev);
|
|
ASSERT(dmu_tx_is_syncing(tx));
|
|
ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops);
|
|
ASSERT(spa_feature_is_active(spa, SPA_FEATURE_OBSOLETE_COUNTS));
|
|
ASSERT(vdev_indirect_mapping_num_entries(vd->vdev_indirect_mapping));
|
|
|
|
uint64_t obsolete_sm_obj;
|
|
VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_obj));
|
|
ASSERT3U(obsolete_sm_obj, !=, 0);
|
|
|
|
scip->scip_vdev = vd->vdev_id;
|
|
scip->scip_next_mapping_object =
|
|
vdev_indirect_mapping_alloc(spa->spa_meta_objset, tx);
|
|
|
|
scip->scip_prev_obsolete_sm_object = obsolete_sm_obj;
|
|
|
|
/*
|
|
* We don't need to allocate a new space map object, since
|
|
* vdev_indirect_sync_obsolete will allocate one when needed.
|
|
*/
|
|
space_map_close(vd->vdev_obsolete_sm);
|
|
vd->vdev_obsolete_sm = NULL;
|
|
VERIFY0(zap_remove(spa->spa_meta_objset, vd->vdev_top_zap,
|
|
VDEV_TOP_ZAP_INDIRECT_OBSOLETE_SM, tx));
|
|
|
|
VERIFY0(zap_add(spa->spa_dsl_pool->dp_meta_objset,
|
|
DMU_POOL_DIRECTORY_OBJECT,
|
|
DMU_POOL_CONDENSING_INDIRECT, sizeof (uint64_t),
|
|
sizeof (*scip) / sizeof (uint64_t), scip, tx));
|
|
|
|
ASSERT3P(spa->spa_condensing_indirect, ==, NULL);
|
|
spa->spa_condensing_indirect = spa_condensing_indirect_create(spa);
|
|
|
|
zfs_dbgmsg("starting condense of vdev %llu in txg %llu: "
|
|
"posm=%llu nm=%llu",
|
|
vd->vdev_id, dmu_tx_get_txg(tx),
|
|
(u_longlong_t)scip->scip_prev_obsolete_sm_object,
|
|
(u_longlong_t)scip->scip_next_mapping_object);
|
|
|
|
zthr_wakeup(spa->spa_condense_zthr);
|
|
}
|
|
|
|
/*
|
|
* Sync to the given vdev's obsolete space map any segments that are no longer
|
|
* referenced as of the given txg.
|
|
*
|
|
* If the obsolete space map doesn't exist yet, create and open it.
|
|
*/
|
|
void
|
|
vdev_indirect_sync_obsolete(vdev_t *vd, dmu_tx_t *tx)
|
|
{
|
|
spa_t *spa = vd->vdev_spa;
|
|
vdev_indirect_config_t *vic __maybe_unused = &vd->vdev_indirect_config;
|
|
|
|
ASSERT3U(vic->vic_mapping_object, !=, 0);
|
|
ASSERT(range_tree_space(vd->vdev_obsolete_segments) > 0);
|
|
ASSERT(vd->vdev_removing || vd->vdev_ops == &vdev_indirect_ops);
|
|
ASSERT(spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS));
|
|
|
|
uint64_t obsolete_sm_object;
|
|
VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
|
|
if (obsolete_sm_object == 0) {
|
|
obsolete_sm_object = space_map_alloc(spa->spa_meta_objset,
|
|
zfs_vdev_standard_sm_blksz, tx);
|
|
|
|
ASSERT(vd->vdev_top_zap != 0);
|
|
VERIFY0(zap_add(vd->vdev_spa->spa_meta_objset, vd->vdev_top_zap,
|
|
VDEV_TOP_ZAP_INDIRECT_OBSOLETE_SM,
|
|
sizeof (obsolete_sm_object), 1, &obsolete_sm_object, tx));
|
|
ASSERT0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
|
|
ASSERT3U(obsolete_sm_object, !=, 0);
|
|
|
|
spa_feature_incr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx);
|
|
VERIFY0(space_map_open(&vd->vdev_obsolete_sm,
|
|
spa->spa_meta_objset, obsolete_sm_object,
|
|
0, vd->vdev_asize, 0));
|
|
}
|
|
|
|
ASSERT(vd->vdev_obsolete_sm != NULL);
|
|
ASSERT3U(obsolete_sm_object, ==,
|
|
space_map_object(vd->vdev_obsolete_sm));
|
|
|
|
space_map_write(vd->vdev_obsolete_sm,
|
|
vd->vdev_obsolete_segments, SM_ALLOC, SM_NO_VDEVID, tx);
|
|
range_tree_vacate(vd->vdev_obsolete_segments, NULL, NULL);
|
|
}
|
|
|
|
int
|
|
spa_condense_init(spa_t *spa)
|
|
{
|
|
int error = zap_lookup(spa->spa_meta_objset,
|
|
DMU_POOL_DIRECTORY_OBJECT,
|
|
DMU_POOL_CONDENSING_INDIRECT, sizeof (uint64_t),
|
|
sizeof (spa->spa_condensing_indirect_phys) / sizeof (uint64_t),
|
|
&spa->spa_condensing_indirect_phys);
|
|
if (error == 0) {
|
|
if (spa_writeable(spa)) {
|
|
spa->spa_condensing_indirect =
|
|
spa_condensing_indirect_create(spa);
|
|
}
|
|
return (0);
|
|
} else if (error == ENOENT) {
|
|
return (0);
|
|
} else {
|
|
return (error);
|
|
}
|
|
}
|
|
|
|
void
|
|
spa_condense_fini(spa_t *spa)
|
|
{
|
|
if (spa->spa_condensing_indirect != NULL) {
|
|
spa_condensing_indirect_destroy(spa->spa_condensing_indirect);
|
|
spa->spa_condensing_indirect = NULL;
|
|
}
|
|
}
|
|
|
|
void
|
|
spa_start_indirect_condensing_thread(spa_t *spa)
|
|
{
|
|
ASSERT3P(spa->spa_condense_zthr, ==, NULL);
|
|
spa->spa_condense_zthr = zthr_create(spa_condense_indirect_thread_check,
|
|
spa_condense_indirect_thread, spa);
|
|
}
|
|
|
|
/*
|
|
* Gets the obsolete spacemap object from the vdev's ZAP. On success sm_obj
|
|
* will contain either the obsolete spacemap object or zero if none exists.
|
|
* All other errors are returned to the caller.
|
|
*/
|
|
int
|
|
vdev_obsolete_sm_object(vdev_t *vd, uint64_t *sm_obj)
|
|
{
|
|
ASSERT0(spa_config_held(vd->vdev_spa, SCL_ALL, RW_WRITER));
|
|
|
|
if (vd->vdev_top_zap == 0) {
|
|
*sm_obj = 0;
|
|
return (0);
|
|
}
|
|
|
|
int error = zap_lookup(vd->vdev_spa->spa_meta_objset, vd->vdev_top_zap,
|
|
VDEV_TOP_ZAP_INDIRECT_OBSOLETE_SM, sizeof (uint64_t), 1, sm_obj);
|
|
if (error == ENOENT) {
|
|
*sm_obj = 0;
|
|
error = 0;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Gets the obsolete count are precise spacemap object from the vdev's ZAP.
|
|
* On success are_precise will be set to reflect if the counts are precise.
|
|
* All other errors are returned to the caller.
|
|
*/
|
|
int
|
|
vdev_obsolete_counts_are_precise(vdev_t *vd, boolean_t *are_precise)
|
|
{
|
|
ASSERT0(spa_config_held(vd->vdev_spa, SCL_ALL, RW_WRITER));
|
|
|
|
if (vd->vdev_top_zap == 0) {
|
|
*are_precise = B_FALSE;
|
|
return (0);
|
|
}
|
|
|
|
uint64_t val = 0;
|
|
int error = zap_lookup(vd->vdev_spa->spa_meta_objset, vd->vdev_top_zap,
|
|
VDEV_TOP_ZAP_OBSOLETE_COUNTS_ARE_PRECISE, sizeof (val), 1, &val);
|
|
if (error == 0) {
|
|
*are_precise = (val != 0);
|
|
} else if (error == ENOENT) {
|
|
*are_precise = B_FALSE;
|
|
error = 0;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static void
|
|
vdev_indirect_close(vdev_t *vd)
|
|
{
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static int
|
|
vdev_indirect_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
|
|
uint64_t *ashift)
|
|
{
|
|
*psize = *max_psize = vd->vdev_asize +
|
|
VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE;
|
|
*ashift = vd->vdev_ashift;
|
|
return (0);
|
|
}
|
|
|
|
typedef struct remap_segment {
|
|
vdev_t *rs_vd;
|
|
uint64_t rs_offset;
|
|
uint64_t rs_asize;
|
|
uint64_t rs_split_offset;
|
|
list_node_t rs_node;
|
|
} remap_segment_t;
|
|
|
|
remap_segment_t *
|
|
rs_alloc(vdev_t *vd, uint64_t offset, uint64_t asize, uint64_t split_offset)
|
|
{
|
|
remap_segment_t *rs = kmem_alloc(sizeof (remap_segment_t), KM_SLEEP);
|
|
rs->rs_vd = vd;
|
|
rs->rs_offset = offset;
|
|
rs->rs_asize = asize;
|
|
rs->rs_split_offset = split_offset;
|
|
return (rs);
|
|
}
|
|
|
|
/*
|
|
* Given an indirect vdev and an extent on that vdev, it duplicates the
|
|
* physical entries of the indirect mapping that correspond to the extent
|
|
* to a new array and returns a pointer to it. In addition, copied_entries
|
|
* is populated with the number of mapping entries that were duplicated.
|
|
*
|
|
* Note that the function assumes that the caller holds vdev_indirect_rwlock.
|
|
* This ensures that the mapping won't change due to condensing as we
|
|
* copy over its contents.
|
|
*
|
|
* Finally, since we are doing an allocation, it is up to the caller to
|
|
* free the array allocated in this function.
|
|
*/
|
|
vdev_indirect_mapping_entry_phys_t *
|
|
vdev_indirect_mapping_duplicate_adjacent_entries(vdev_t *vd, uint64_t offset,
|
|
uint64_t asize, uint64_t *copied_entries)
|
|
{
|
|
vdev_indirect_mapping_entry_phys_t *duplicate_mappings = NULL;
|
|
vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping;
|
|
uint64_t entries = 0;
|
|
|
|
ASSERT(RW_READ_HELD(&vd->vdev_indirect_rwlock));
|
|
|
|
vdev_indirect_mapping_entry_phys_t *first_mapping =
|
|
vdev_indirect_mapping_entry_for_offset(vim, offset);
|
|
ASSERT3P(first_mapping, !=, NULL);
|
|
|
|
vdev_indirect_mapping_entry_phys_t *m = first_mapping;
|
|
while (asize > 0) {
|
|
uint64_t size = DVA_GET_ASIZE(&m->vimep_dst);
|
|
|
|
ASSERT3U(offset, >=, DVA_MAPPING_GET_SRC_OFFSET(m));
|
|
ASSERT3U(offset, <, DVA_MAPPING_GET_SRC_OFFSET(m) + size);
|
|
|
|
uint64_t inner_offset = offset - DVA_MAPPING_GET_SRC_OFFSET(m);
|
|
uint64_t inner_size = MIN(asize, size - inner_offset);
|
|
|
|
offset += inner_size;
|
|
asize -= inner_size;
|
|
entries++;
|
|
m++;
|
|
}
|
|
|
|
size_t copy_length = entries * sizeof (*first_mapping);
|
|
duplicate_mappings = kmem_alloc(copy_length, KM_SLEEP);
|
|
bcopy(first_mapping, duplicate_mappings, copy_length);
|
|
*copied_entries = entries;
|
|
|
|
return (duplicate_mappings);
|
|
}
|
|
|
|
/*
|
|
* Goes through the relevant indirect mappings until it hits a concrete vdev
|
|
* and issues the callback. On the way to the concrete vdev, if any other
|
|
* indirect vdevs are encountered, then the callback will also be called on
|
|
* each of those indirect vdevs. For example, if the segment is mapped to
|
|
* segment A on indirect vdev 1, and then segment A on indirect vdev 1 is
|
|
* mapped to segment B on concrete vdev 2, then the callback will be called on
|
|
* both vdev 1 and vdev 2.
|
|
*
|
|
* While the callback passed to vdev_indirect_remap() is called on every vdev
|
|
* the function encounters, certain callbacks only care about concrete vdevs.
|
|
* These types of callbacks should return immediately and explicitly when they
|
|
* are called on an indirect vdev.
|
|
*
|
|
* Because there is a possibility that a DVA section in the indirect device
|
|
* has been split into multiple sections in our mapping, we keep track
|
|
* of the relevant contiguous segments of the new location (remap_segment_t)
|
|
* in a stack. This way we can call the callback for each of the new sections
|
|
* created by a single section of the indirect device. Note though, that in
|
|
* this scenario the callbacks in each split block won't occur in-order in
|
|
* terms of offset, so callers should not make any assumptions about that.
|
|
*
|
|
* For callbacks that don't handle split blocks and immediately return when
|
|
* they encounter them (as is the case for remap_blkptr_cb), the caller can
|
|
* assume that its callback will be applied from the first indirect vdev
|
|
* encountered to the last one and then the concrete vdev, in that order.
|
|
*/
|
|
static void
|
|
vdev_indirect_remap(vdev_t *vd, uint64_t offset, uint64_t asize,
|
|
void (*func)(uint64_t, vdev_t *, uint64_t, uint64_t, void *), void *arg)
|
|
{
|
|
list_t stack;
|
|
spa_t *spa = vd->vdev_spa;
|
|
|
|
list_create(&stack, sizeof (remap_segment_t),
|
|
offsetof(remap_segment_t, rs_node));
|
|
|
|
for (remap_segment_t *rs = rs_alloc(vd, offset, asize, 0);
|
|
rs != NULL; rs = list_remove_head(&stack)) {
|
|
vdev_t *v = rs->rs_vd;
|
|
uint64_t num_entries = 0;
|
|
|
|
ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
|
|
ASSERT(rs->rs_asize > 0);
|
|
|
|
/*
|
|
* Note: As this function can be called from open context
|
|
* (e.g. zio_read()), we need the following rwlock to
|
|
* prevent the mapping from being changed by condensing.
|
|
*
|
|
* So we grab the lock and we make a copy of the entries
|
|
* that are relevant to the extent that we are working on.
|
|
* Once that is done, we drop the lock and iterate over
|
|
* our copy of the mapping. Once we are done with the with
|
|
* the remap segment and we free it, we also free our copy
|
|
* of the indirect mapping entries that are relevant to it.
|
|
*
|
|
* This way we don't need to wait until the function is
|
|
* finished with a segment, to condense it. In addition, we
|
|
* don't need a recursive rwlock for the case that a call to
|
|
* vdev_indirect_remap() needs to call itself (through the
|
|
* codepath of its callback) for the same vdev in the middle
|
|
* of its execution.
|
|
*/
|
|
rw_enter(&v->vdev_indirect_rwlock, RW_READER);
|
|
ASSERT3P(v->vdev_indirect_mapping, !=, NULL);
|
|
|
|
vdev_indirect_mapping_entry_phys_t *mapping =
|
|
vdev_indirect_mapping_duplicate_adjacent_entries(v,
|
|
rs->rs_offset, rs->rs_asize, &num_entries);
|
|
ASSERT3P(mapping, !=, NULL);
|
|
ASSERT3U(num_entries, >, 0);
|
|
rw_exit(&v->vdev_indirect_rwlock);
|
|
|
|
for (uint64_t i = 0; i < num_entries; i++) {
|
|
/*
|
|
* Note: the vdev_indirect_mapping can not change
|
|
* while we are running. It only changes while the
|
|
* removal is in progress, and then only from syncing
|
|
* context. While a removal is in progress, this
|
|
* function is only called for frees, which also only
|
|
* happen from syncing context.
|
|
*/
|
|
vdev_indirect_mapping_entry_phys_t *m = &mapping[i];
|
|
|
|
ASSERT3P(m, !=, NULL);
|
|
ASSERT3U(rs->rs_asize, >, 0);
|
|
|
|
uint64_t size = DVA_GET_ASIZE(&m->vimep_dst);
|
|
uint64_t dst_offset = DVA_GET_OFFSET(&m->vimep_dst);
|
|
uint64_t dst_vdev = DVA_GET_VDEV(&m->vimep_dst);
|
|
|
|
ASSERT3U(rs->rs_offset, >=,
|
|
DVA_MAPPING_GET_SRC_OFFSET(m));
|
|
ASSERT3U(rs->rs_offset, <,
|
|
DVA_MAPPING_GET_SRC_OFFSET(m) + size);
|
|
ASSERT3U(dst_vdev, !=, v->vdev_id);
|
|
|
|
uint64_t inner_offset = rs->rs_offset -
|
|
DVA_MAPPING_GET_SRC_OFFSET(m);
|
|
uint64_t inner_size =
|
|
MIN(rs->rs_asize, size - inner_offset);
|
|
|
|
vdev_t *dst_v = vdev_lookup_top(spa, dst_vdev);
|
|
ASSERT3P(dst_v, !=, NULL);
|
|
|
|
if (dst_v->vdev_ops == &vdev_indirect_ops) {
|
|
list_insert_head(&stack,
|
|
rs_alloc(dst_v, dst_offset + inner_offset,
|
|
inner_size, rs->rs_split_offset));
|
|
|
|
}
|
|
|
|
if ((zfs_flags & ZFS_DEBUG_INDIRECT_REMAP) &&
|
|
IS_P2ALIGNED(inner_size, 2 * SPA_MINBLOCKSIZE)) {
|
|
/*
|
|
* Note: This clause exists only solely for
|
|
* testing purposes. We use it to ensure that
|
|
* split blocks work and that the callbacks
|
|
* using them yield the same result if issued
|
|
* in reverse order.
|
|
*/
|
|
uint64_t inner_half = inner_size / 2;
|
|
|
|
func(rs->rs_split_offset + inner_half, dst_v,
|
|
dst_offset + inner_offset + inner_half,
|
|
inner_half, arg);
|
|
|
|
func(rs->rs_split_offset, dst_v,
|
|
dst_offset + inner_offset,
|
|
inner_half, arg);
|
|
} else {
|
|
func(rs->rs_split_offset, dst_v,
|
|
dst_offset + inner_offset,
|
|
inner_size, arg);
|
|
}
|
|
|
|
rs->rs_offset += inner_size;
|
|
rs->rs_asize -= inner_size;
|
|
rs->rs_split_offset += inner_size;
|
|
}
|
|
VERIFY0(rs->rs_asize);
|
|
|
|
kmem_free(mapping, num_entries * sizeof (*mapping));
|
|
kmem_free(rs, sizeof (remap_segment_t));
|
|
}
|
|
list_destroy(&stack);
|
|
}
|
|
|
|
static void
|
|
vdev_indirect_child_io_done(zio_t *zio)
|
|
{
|
|
zio_t *pio = zio->io_private;
|
|
|
|
mutex_enter(&pio->io_lock);
|
|
pio->io_error = zio_worst_error(pio->io_error, zio->io_error);
|
|
mutex_exit(&pio->io_lock);
|
|
|
|
abd_put(zio->io_abd);
|
|
}
|
|
|
|
/*
|
|
* This is a callback for vdev_indirect_remap() which allocates an
|
|
* indirect_split_t for each split segment and adds it to iv_splits.
|
|
*/
|
|
static void
|
|
vdev_indirect_gather_splits(uint64_t split_offset, vdev_t *vd, uint64_t offset,
|
|
uint64_t size, void *arg)
|
|
{
|
|
zio_t *zio = arg;
|
|
indirect_vsd_t *iv = zio->io_vsd;
|
|
|
|
ASSERT3P(vd, !=, NULL);
|
|
|
|
if (vd->vdev_ops == &vdev_indirect_ops)
|
|
return;
|
|
|
|
int n = 1;
|
|
if (vd->vdev_ops == &vdev_mirror_ops)
|
|
n = vd->vdev_children;
|
|
|
|
indirect_split_t *is =
|
|
kmem_zalloc(offsetof(indirect_split_t, is_child[n]), KM_SLEEP);
|
|
|
|
is->is_children = n;
|
|
is->is_size = size;
|
|
is->is_split_offset = split_offset;
|
|
is->is_target_offset = offset;
|
|
is->is_vdev = vd;
|
|
list_create(&is->is_unique_child, sizeof (indirect_child_t),
|
|
offsetof(indirect_child_t, ic_node));
|
|
|
|
/*
|
|
* Note that we only consider multiple copies of the data for
|
|
* *mirror* vdevs. We don't for "replacing" or "spare" vdevs, even
|
|
* though they use the same ops as mirror, because there's only one
|
|
* "good" copy under the replacing/spare.
|
|
*/
|
|
if (vd->vdev_ops == &vdev_mirror_ops) {
|
|
for (int i = 0; i < n; i++) {
|
|
is->is_child[i].ic_vdev = vd->vdev_child[i];
|
|
list_link_init(&is->is_child[i].ic_node);
|
|
}
|
|
} else {
|
|
is->is_child[0].ic_vdev = vd;
|
|
}
|
|
|
|
list_insert_tail(&iv->iv_splits, is);
|
|
}
|
|
|
|
static void
|
|
vdev_indirect_read_split_done(zio_t *zio)
|
|
{
|
|
indirect_child_t *ic = zio->io_private;
|
|
|
|
if (zio->io_error != 0) {
|
|
/*
|
|
* Clear ic_data to indicate that we do not have data for this
|
|
* child.
|
|
*/
|
|
abd_free(ic->ic_data);
|
|
ic->ic_data = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Issue reads for all copies (mirror children) of all splits.
|
|
*/
|
|
static void
|
|
vdev_indirect_read_all(zio_t *zio)
|
|
{
|
|
indirect_vsd_t *iv = zio->io_vsd;
|
|
|
|
ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ);
|
|
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
for (int i = 0; i < is->is_children; i++) {
|
|
indirect_child_t *ic = &is->is_child[i];
|
|
|
|
if (!vdev_readable(ic->ic_vdev))
|
|
continue;
|
|
|
|
/*
|
|
* Note, we may read from a child whose DTL
|
|
* indicates that the data may not be present here.
|
|
* While this might result in a few i/os that will
|
|
* likely return incorrect data, it simplifies the
|
|
* code since we can treat scrub and resilver
|
|
* identically. (The incorrect data will be
|
|
* detected and ignored when we verify the
|
|
* checksum.)
|
|
*/
|
|
|
|
ic->ic_data = abd_alloc_sametype(zio->io_abd,
|
|
is->is_size);
|
|
ic->ic_duplicate = NULL;
|
|
|
|
zio_nowait(zio_vdev_child_io(zio, NULL,
|
|
ic->ic_vdev, is->is_target_offset, ic->ic_data,
|
|
is->is_size, zio->io_type, zio->io_priority, 0,
|
|
vdev_indirect_read_split_done, ic));
|
|
}
|
|
}
|
|
iv->iv_reconstruct = B_TRUE;
|
|
}
|
|
|
|
static void
|
|
vdev_indirect_io_start(zio_t *zio)
|
|
{
|
|
spa_t *spa __maybe_unused = zio->io_spa;
|
|
indirect_vsd_t *iv = kmem_zalloc(sizeof (*iv), KM_SLEEP);
|
|
list_create(&iv->iv_splits,
|
|
sizeof (indirect_split_t), offsetof(indirect_split_t, is_node));
|
|
|
|
zio->io_vsd = iv;
|
|
zio->io_vsd_ops = &vdev_indirect_vsd_ops;
|
|
|
|
ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
|
|
if (zio->io_type != ZIO_TYPE_READ) {
|
|
ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE);
|
|
/*
|
|
* Note: this code can handle other kinds of writes,
|
|
* but we don't expect them.
|
|
*/
|
|
ASSERT((zio->io_flags & (ZIO_FLAG_SELF_HEAL |
|
|
ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE)) != 0);
|
|
}
|
|
|
|
vdev_indirect_remap(zio->io_vd, zio->io_offset, zio->io_size,
|
|
vdev_indirect_gather_splits, zio);
|
|
|
|
indirect_split_t *first = list_head(&iv->iv_splits);
|
|
if (first->is_size == zio->io_size) {
|
|
/*
|
|
* This is not a split block; we are pointing to the entire
|
|
* data, which will checksum the same as the original data.
|
|
* Pass the BP down so that the child i/o can verify the
|
|
* checksum, and try a different location if available
|
|
* (e.g. on a mirror).
|
|
*
|
|
* While this special case could be handled the same as the
|
|
* general (split block) case, doing it this way ensures
|
|
* that the vast majority of blocks on indirect vdevs
|
|
* (which are not split) are handled identically to blocks
|
|
* on non-indirect vdevs. This allows us to be less strict
|
|
* about performance in the general (but rare) case.
|
|
*/
|
|
ASSERT0(first->is_split_offset);
|
|
ASSERT3P(list_next(&iv->iv_splits, first), ==, NULL);
|
|
zio_nowait(zio_vdev_child_io(zio, zio->io_bp,
|
|
first->is_vdev, first->is_target_offset,
|
|
abd_get_offset(zio->io_abd, 0),
|
|
zio->io_size, zio->io_type, zio->io_priority, 0,
|
|
vdev_indirect_child_io_done, zio));
|
|
} else {
|
|
iv->iv_split_block = B_TRUE;
|
|
if (zio->io_type == ZIO_TYPE_READ &&
|
|
zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER)) {
|
|
/*
|
|
* Read all copies. Note that for simplicity,
|
|
* we don't bother consulting the DTL in the
|
|
* resilver case.
|
|
*/
|
|
vdev_indirect_read_all(zio);
|
|
} else {
|
|
/*
|
|
* If this is a read zio, we read one copy of each
|
|
* split segment, from the top-level vdev. Since
|
|
* we don't know the checksum of each split
|
|
* individually, the child zio can't ensure that
|
|
* we get the right data. E.g. if it's a mirror,
|
|
* it will just read from a random (healthy) leaf
|
|
* vdev. We have to verify the checksum in
|
|
* vdev_indirect_io_done().
|
|
*
|
|
* For write zios, the vdev code will ensure we write
|
|
* to all children.
|
|
*/
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
zio_nowait(zio_vdev_child_io(zio, NULL,
|
|
is->is_vdev, is->is_target_offset,
|
|
abd_get_offset(zio->io_abd,
|
|
is->is_split_offset), is->is_size,
|
|
zio->io_type, zio->io_priority, 0,
|
|
vdev_indirect_child_io_done, zio));
|
|
}
|
|
|
|
}
|
|
}
|
|
|
|
zio_execute(zio);
|
|
}
|
|
|
|
/*
|
|
* Report a checksum error for a child.
|
|
*/
|
|
static void
|
|
vdev_indirect_checksum_error(zio_t *zio,
|
|
indirect_split_t *is, indirect_child_t *ic)
|
|
{
|
|
vdev_t *vd = ic->ic_vdev;
|
|
|
|
if (zio->io_flags & ZIO_FLAG_SPECULATIVE)
|
|
return;
|
|
|
|
mutex_enter(&vd->vdev_stat_lock);
|
|
vd->vdev_stat.vs_checksum_errors++;
|
|
mutex_exit(&vd->vdev_stat_lock);
|
|
|
|
zio_bad_cksum_t zbc = {{{ 0 }}};
|
|
abd_t *bad_abd = ic->ic_data;
|
|
abd_t *good_abd = is->is_good_child->ic_data;
|
|
zfs_ereport_post_checksum(zio->io_spa, vd, NULL, zio,
|
|
is->is_target_offset, is->is_size, good_abd, bad_abd, &zbc);
|
|
}
|
|
|
|
/*
|
|
* Issue repair i/os for any incorrect copies. We do this by comparing
|
|
* each split segment's correct data (is_good_child's ic_data) with each
|
|
* other copy of the data. If they differ, then we overwrite the bad data
|
|
* with the good copy. Note that we do this without regard for the DTL's,
|
|
* which simplifies this code and also issues the optimal number of writes
|
|
* (based on which copies actually read bad data, as opposed to which we
|
|
* think might be wrong). For the same reason, we always use
|
|
* ZIO_FLAG_SELF_HEAL, to bypass the DTL check in zio_vdev_io_start().
|
|
*/
|
|
static void
|
|
vdev_indirect_repair(zio_t *zio)
|
|
{
|
|
indirect_vsd_t *iv = zio->io_vsd;
|
|
|
|
enum zio_flag flags = ZIO_FLAG_IO_REPAIR;
|
|
|
|
if (!(zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER)))
|
|
flags |= ZIO_FLAG_SELF_HEAL;
|
|
|
|
if (!spa_writeable(zio->io_spa))
|
|
return;
|
|
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
for (int c = 0; c < is->is_children; c++) {
|
|
indirect_child_t *ic = &is->is_child[c];
|
|
if (ic == is->is_good_child)
|
|
continue;
|
|
if (ic->ic_data == NULL)
|
|
continue;
|
|
if (ic->ic_duplicate == is->is_good_child)
|
|
continue;
|
|
|
|
zio_nowait(zio_vdev_child_io(zio, NULL,
|
|
ic->ic_vdev, is->is_target_offset,
|
|
is->is_good_child->ic_data, is->is_size,
|
|
ZIO_TYPE_WRITE, ZIO_PRIORITY_ASYNC_WRITE,
|
|
ZIO_FLAG_IO_REPAIR | ZIO_FLAG_SELF_HEAL,
|
|
NULL, NULL));
|
|
|
|
vdev_indirect_checksum_error(zio, is, ic);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Report checksum errors on all children that we read from.
|
|
*/
|
|
static void
|
|
vdev_indirect_all_checksum_errors(zio_t *zio)
|
|
{
|
|
indirect_vsd_t *iv = zio->io_vsd;
|
|
|
|
if (zio->io_flags & ZIO_FLAG_SPECULATIVE)
|
|
return;
|
|
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
for (int c = 0; c < is->is_children; c++) {
|
|
indirect_child_t *ic = &is->is_child[c];
|
|
|
|
if (ic->ic_data == NULL)
|
|
continue;
|
|
|
|
vdev_t *vd = ic->ic_vdev;
|
|
|
|
mutex_enter(&vd->vdev_stat_lock);
|
|
vd->vdev_stat.vs_checksum_errors++;
|
|
mutex_exit(&vd->vdev_stat_lock);
|
|
|
|
zfs_ereport_post_checksum(zio->io_spa, vd, NULL, zio,
|
|
is->is_target_offset, is->is_size,
|
|
NULL, NULL, NULL);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy data from all the splits to a main zio then validate the checksum.
|
|
* If then checksum is successfully validated return success.
|
|
*/
|
|
static int
|
|
vdev_indirect_splits_checksum_validate(indirect_vsd_t *iv, zio_t *zio)
|
|
{
|
|
zio_bad_cksum_t zbc;
|
|
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
|
|
ASSERT3P(is->is_good_child->ic_data, !=, NULL);
|
|
ASSERT3P(is->is_good_child->ic_duplicate, ==, NULL);
|
|
|
|
abd_copy_off(zio->io_abd, is->is_good_child->ic_data,
|
|
is->is_split_offset, 0, is->is_size);
|
|
}
|
|
|
|
return (zio_checksum_error(zio, &zbc));
|
|
}
|
|
|
|
/*
|
|
* There are relatively few possible combinations making it feasible to
|
|
* deterministically check them all. We do this by setting the good_child
|
|
* to the next unique split version. If we reach the end of the list then
|
|
* "carry over" to the next unique split version (like counting in base
|
|
* is_unique_children, but each digit can have a different base).
|
|
*/
|
|
static int
|
|
vdev_indirect_splits_enumerate_all(indirect_vsd_t *iv, zio_t *zio)
|
|
{
|
|
boolean_t more = B_TRUE;
|
|
|
|
iv->iv_attempts = 0;
|
|
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is))
|
|
is->is_good_child = list_head(&is->is_unique_child);
|
|
|
|
while (more == B_TRUE) {
|
|
iv->iv_attempts++;
|
|
more = B_FALSE;
|
|
|
|
if (vdev_indirect_splits_checksum_validate(iv, zio) == 0)
|
|
return (0);
|
|
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
is->is_good_child = list_next(&is->is_unique_child,
|
|
is->is_good_child);
|
|
if (is->is_good_child != NULL) {
|
|
more = B_TRUE;
|
|
break;
|
|
}
|
|
|
|
is->is_good_child = list_head(&is->is_unique_child);
|
|
}
|
|
}
|
|
|
|
ASSERT3S(iv->iv_attempts, <=, iv->iv_unique_combinations);
|
|
|
|
return (SET_ERROR(ECKSUM));
|
|
}
|
|
|
|
/*
|
|
* There are too many combinations to try all of them in a reasonable amount
|
|
* of time. So try a fixed number of random combinations from the unique
|
|
* split versions, after which we'll consider the block unrecoverable.
|
|
*/
|
|
static int
|
|
vdev_indirect_splits_enumerate_randomly(indirect_vsd_t *iv, zio_t *zio)
|
|
{
|
|
iv->iv_attempts = 0;
|
|
|
|
while (iv->iv_attempts < iv->iv_attempts_max) {
|
|
iv->iv_attempts++;
|
|
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
indirect_child_t *ic = list_head(&is->is_unique_child);
|
|
int children = is->is_unique_children;
|
|
|
|
for (int i = spa_get_random(children); i > 0; i--)
|
|
ic = list_next(&is->is_unique_child, ic);
|
|
|
|
ASSERT3P(ic, !=, NULL);
|
|
is->is_good_child = ic;
|
|
}
|
|
|
|
if (vdev_indirect_splits_checksum_validate(iv, zio) == 0)
|
|
return (0);
|
|
}
|
|
|
|
return (SET_ERROR(ECKSUM));
|
|
}
|
|
|
|
/*
|
|
* This is a validation function for reconstruction. It randomly selects
|
|
* a good combination, if one can be found, and then it intentionally
|
|
* damages all other segment copes by zeroing them. This forces the
|
|
* reconstruction algorithm to locate the one remaining known good copy.
|
|
*/
|
|
static int
|
|
vdev_indirect_splits_damage(indirect_vsd_t *iv, zio_t *zio)
|
|
{
|
|
int error;
|
|
|
|
/* Presume all the copies are unique for initial selection. */
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
is->is_unique_children = 0;
|
|
|
|
for (int i = 0; i < is->is_children; i++) {
|
|
indirect_child_t *ic = &is->is_child[i];
|
|
if (ic->ic_data != NULL) {
|
|
is->is_unique_children++;
|
|
list_insert_tail(&is->is_unique_child, ic);
|
|
}
|
|
}
|
|
|
|
if (list_is_empty(&is->is_unique_child)) {
|
|
error = SET_ERROR(EIO);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set each is_good_child to a randomly-selected child which
|
|
* is known to contain validated data.
|
|
*/
|
|
error = vdev_indirect_splits_enumerate_randomly(iv, zio);
|
|
if (error)
|
|
goto out;
|
|
|
|
/*
|
|
* Damage all but the known good copy by zeroing it. This will
|
|
* result in two or less unique copies per indirect_child_t.
|
|
* Both may need to be checked in order to reconstruct the block.
|
|
* Set iv->iv_attempts_max such that all unique combinations will
|
|
* enumerated, but limit the damage to at most 12 indirect splits.
|
|
*/
|
|
iv->iv_attempts_max = 1;
|
|
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
for (int c = 0; c < is->is_children; c++) {
|
|
indirect_child_t *ic = &is->is_child[c];
|
|
|
|
if (ic == is->is_good_child)
|
|
continue;
|
|
if (ic->ic_data == NULL)
|
|
continue;
|
|
|
|
abd_zero(ic->ic_data, ic->ic_data->abd_size);
|
|
}
|
|
|
|
iv->iv_attempts_max *= 2;
|
|
if (iv->iv_attempts_max >= (1ULL << 12)) {
|
|
iv->iv_attempts_max = UINT64_MAX;
|
|
break;
|
|
}
|
|
}
|
|
|
|
out:
|
|
/* Empty the unique children lists so they can be reconstructed. */
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
indirect_child_t *ic;
|
|
while ((ic = list_head(&is->is_unique_child)) != NULL)
|
|
list_remove(&is->is_unique_child, ic);
|
|
|
|
is->is_unique_children = 0;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* This function is called when we have read all copies of the data and need
|
|
* to try to find a combination of copies that gives us the right checksum.
|
|
*
|
|
* If we pointed to any mirror vdevs, this effectively does the job of the
|
|
* mirror. The mirror vdev code can't do its own job because we don't know
|
|
* the checksum of each split segment individually.
|
|
*
|
|
* We have to try every unique combination of copies of split segments, until
|
|
* we find one that checksums correctly. Duplicate segment copies are first
|
|
* identified and latter skipped during reconstruction. This optimization
|
|
* reduces the search space and ensures that of the remaining combinations
|
|
* at most one is correct.
|
|
*
|
|
* When the total number of combinations is small they can all be checked.
|
|
* For example, if we have 3 segments in the split, and each points to a
|
|
* 2-way mirror with unique copies, we will have the following pieces of data:
|
|
*
|
|
* | mirror child
|
|
* split | [0] [1]
|
|
* ======|=====================
|
|
* A | data_A_0 data_A_1
|
|
* B | data_B_0 data_B_1
|
|
* C | data_C_0 data_C_1
|
|
*
|
|
* We will try the following (mirror children)^(number of splits) (2^3=8)
|
|
* combinations, which is similar to bitwise-little-endian counting in
|
|
* binary. In general each "digit" corresponds to a split segment, and the
|
|
* base of each digit is is_children, which can be different for each
|
|
* digit.
|
|
*
|
|
* "low bit" "high bit"
|
|
* v v
|
|
* data_A_0 data_B_0 data_C_0
|
|
* data_A_1 data_B_0 data_C_0
|
|
* data_A_0 data_B_1 data_C_0
|
|
* data_A_1 data_B_1 data_C_0
|
|
* data_A_0 data_B_0 data_C_1
|
|
* data_A_1 data_B_0 data_C_1
|
|
* data_A_0 data_B_1 data_C_1
|
|
* data_A_1 data_B_1 data_C_1
|
|
*
|
|
* Note that the split segments may be on the same or different top-level
|
|
* vdevs. In either case, we may need to try lots of combinations (see
|
|
* zfs_reconstruct_indirect_combinations_max). This ensures that if a mirror
|
|
* has small silent errors on all of its children, we can still reconstruct
|
|
* the correct data, as long as those errors are at sufficiently-separated
|
|
* offsets (specifically, separated by the largest block size - default of
|
|
* 128KB, but up to 16MB).
|
|
*/
|
|
static void
|
|
vdev_indirect_reconstruct_io_done(zio_t *zio)
|
|
{
|
|
indirect_vsd_t *iv = zio->io_vsd;
|
|
boolean_t known_good = B_FALSE;
|
|
int error;
|
|
|
|
iv->iv_unique_combinations = 1;
|
|
iv->iv_attempts_max = UINT64_MAX;
|
|
|
|
if (zfs_reconstruct_indirect_combinations_max > 0)
|
|
iv->iv_attempts_max = zfs_reconstruct_indirect_combinations_max;
|
|
|
|
/*
|
|
* If nonzero, every 1/x blocks will be damaged, in order to validate
|
|
* reconstruction when there are split segments with damaged copies.
|
|
* Known_good will be TRUE when reconstruction is known to be possible.
|
|
*/
|
|
if (zfs_reconstruct_indirect_damage_fraction != 0 &&
|
|
spa_get_random(zfs_reconstruct_indirect_damage_fraction) == 0)
|
|
known_good = (vdev_indirect_splits_damage(iv, zio) == 0);
|
|
|
|
/*
|
|
* Determine the unique children for a split segment and add them
|
|
* to the is_unique_child list. By restricting reconstruction
|
|
* to these children, only unique combinations will be considered.
|
|
* This can vastly reduce the search space when there are a large
|
|
* number of indirect splits.
|
|
*/
|
|
for (indirect_split_t *is = list_head(&iv->iv_splits);
|
|
is != NULL; is = list_next(&iv->iv_splits, is)) {
|
|
is->is_unique_children = 0;
|
|
|
|
for (int i = 0; i < is->is_children; i++) {
|
|
indirect_child_t *ic_i = &is->is_child[i];
|
|
|
|
if (ic_i->ic_data == NULL ||
|
|
ic_i->ic_duplicate != NULL)
|
|
continue;
|
|
|
|
for (int j = i + 1; j < is->is_children; j++) {
|
|
indirect_child_t *ic_j = &is->is_child[j];
|
|
|
|
if (ic_j->ic_data == NULL ||
|
|
ic_j->ic_duplicate != NULL)
|
|
continue;
|
|
|
|
if (abd_cmp(ic_i->ic_data, ic_j->ic_data) == 0)
|
|
ic_j->ic_duplicate = ic_i;
|
|
}
|
|
|
|
is->is_unique_children++;
|
|
list_insert_tail(&is->is_unique_child, ic_i);
|
|
}
|
|
|
|
/* Reconstruction is impossible, no valid children */
|
|
EQUIV(list_is_empty(&is->is_unique_child),
|
|
is->is_unique_children == 0);
|
|
if (list_is_empty(&is->is_unique_child)) {
|
|
zio->io_error = EIO;
|
|
vdev_indirect_all_checksum_errors(zio);
|
|
zio_checksum_verified(zio);
|
|
return;
|
|
}
|
|
|
|
iv->iv_unique_combinations *= is->is_unique_children;
|
|
}
|
|
|
|
if (iv->iv_unique_combinations <= iv->iv_attempts_max)
|
|
error = vdev_indirect_splits_enumerate_all(iv, zio);
|
|
else
|
|
error = vdev_indirect_splits_enumerate_randomly(iv, zio);
|
|
|
|
if (error != 0) {
|
|
/* All attempted combinations failed. */
|
|
ASSERT3B(known_good, ==, B_FALSE);
|
|
zio->io_error = error;
|
|
vdev_indirect_all_checksum_errors(zio);
|
|
} else {
|
|
/*
|
|
* The checksum has been successfully validated. Issue
|
|
* repair I/Os to any copies of splits which don't match
|
|
* the validated version.
|
|
*/
|
|
ASSERT0(vdev_indirect_splits_checksum_validate(iv, zio));
|
|
vdev_indirect_repair(zio);
|
|
zio_checksum_verified(zio);
|
|
}
|
|
}
|
|
|
|
static void
|
|
vdev_indirect_io_done(zio_t *zio)
|
|
{
|
|
indirect_vsd_t *iv = zio->io_vsd;
|
|
|
|
if (iv->iv_reconstruct) {
|
|
/*
|
|
* We have read all copies of the data (e.g. from mirrors),
|
|
* either because this was a scrub/resilver, or because the
|
|
* one-copy read didn't checksum correctly.
|
|
*/
|
|
vdev_indirect_reconstruct_io_done(zio);
|
|
return;
|
|
}
|
|
|
|
if (!iv->iv_split_block) {
|
|
/*
|
|
* This was not a split block, so we passed the BP down,
|
|
* and the checksum was handled by the (one) child zio.
|
|
*/
|
|
return;
|
|
}
|
|
|
|
zio_bad_cksum_t zbc;
|
|
int ret = zio_checksum_error(zio, &zbc);
|
|
if (ret == 0) {
|
|
zio_checksum_verified(zio);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The checksum didn't match. Read all copies of all splits, and
|
|
* then we will try to reconstruct. The next time
|
|
* vdev_indirect_io_done() is called, iv_reconstruct will be set.
|
|
*/
|
|
vdev_indirect_read_all(zio);
|
|
|
|
zio_vdev_io_redone(zio);
|
|
}
|
|
|
|
vdev_ops_t vdev_indirect_ops = {
|
|
.vdev_op_open = vdev_indirect_open,
|
|
.vdev_op_close = vdev_indirect_close,
|
|
.vdev_op_asize = vdev_default_asize,
|
|
.vdev_op_io_start = vdev_indirect_io_start,
|
|
.vdev_op_io_done = vdev_indirect_io_done,
|
|
.vdev_op_state_change = NULL,
|
|
.vdev_op_need_resilver = NULL,
|
|
.vdev_op_hold = NULL,
|
|
.vdev_op_rele = NULL,
|
|
.vdev_op_remap = vdev_indirect_remap,
|
|
.vdev_op_xlate = NULL,
|
|
.vdev_op_type = VDEV_TYPE_INDIRECT, /* name of this vdev type */
|
|
.vdev_op_leaf = B_FALSE /* leaf vdev */
|
|
};
|
|
|
|
EXPORT_SYMBOL(rs_alloc);
|
|
EXPORT_SYMBOL(spa_condense_fini);
|
|
EXPORT_SYMBOL(spa_start_indirect_condensing_thread);
|
|
EXPORT_SYMBOL(spa_condense_indirect_start_sync);
|
|
EXPORT_SYMBOL(spa_condense_init);
|
|
EXPORT_SYMBOL(spa_vdev_indirect_mark_obsolete);
|
|
EXPORT_SYMBOL(vdev_indirect_mark_obsolete);
|
|
EXPORT_SYMBOL(vdev_indirect_should_condense);
|
|
EXPORT_SYMBOL(vdev_indirect_sync_obsolete);
|
|
EXPORT_SYMBOL(vdev_obsolete_counts_are_precise);
|
|
EXPORT_SYMBOL(vdev_obsolete_sm_object);
|
|
|
|
/* BEGIN CSTYLED */
|
|
ZFS_MODULE_PARAM(zfs_condense, zfs_condense_, indirect_vdevs_enable, INT, ZMOD_RW,
|
|
"Whether to attempt condensing indirect vdev mappings");
|
|
|
|
ZFS_MODULE_PARAM(zfs_condense, zfs_condense_, min_mapping_bytes, ULONG, ZMOD_RW,
|
|
"Don't bother condensing if the mapping uses less than this amount of "
|
|
"memory");
|
|
|
|
ZFS_MODULE_PARAM(zfs_condense, zfs_condense_, max_obsolete_bytes, ULONG, ZMOD_RW,
|
|
"Minimum size obsolete spacemap to attempt condensing");
|
|
|
|
ZFS_MODULE_PARAM(zfs_condense, zfs_condense_, indirect_commit_entry_delay_ms, INT, ZMOD_RW,
|
|
"Used by tests to ensure certain actions happen in the middle of a "
|
|
"condense. A maximum value of 1 should be sufficient.");
|
|
|
|
ZFS_MODULE_PARAM(zfs_reconstruct, zfs_reconstruct_, indirect_combinations_max, INT, ZMOD_RW,
|
|
"Maximum number of combinations when reconstructing split segments");
|
|
/* END CSTYLED */
|