/*
* Copyright (c) 2020 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* $Id: //eng/vdo-releases/aluminum/src/c++/vdo/base/slabSummaryInternals.h#7 $
*/
#ifndef SLAB_SUMMARY_INTERNALS_H
#define SLAB_SUMMARY_INTERNALS_H
#include "slabSummary.h"
#include "adminState.h"
#include "atomic.h"
typedef struct slabSummaryEntry {
/** Bits 7..0: The offset of the tail block within the slab journal */
TailBlockOffset tailBlockOffset;
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
/** Bits 13..8: A hint about the fullness of the slab */
unsigned int fullnessHint : 6;
/** Bit 14: Whether the refCounts must be loaded from the layer */
unsigned int loadRefCounts : 1;
/** Bit 15: The believed cleanliness of this slab */
unsigned int isDirty : 1;
#else
/** Bit 15: The believed cleanliness of this slab */
unsigned int isDirty : 1;
/** Bit 14: Whether the refCounts must be loaded from the layer */
unsigned int loadRefCounts : 1;
/** Bits 13..8: A hint about the fullness of the slab */
unsigned int fullnessHint : 6;
#endif
} __attribute__((packed)) SlabSummaryEntry;
typedef struct slabSummaryBlock {
/** The zone to which this block belongs */
SlabSummaryZone *zone;
/** The index of this block in its zone's summary */
BlockCount index;
/** Whether this block has a write outstanding */
bool writing;
/** Ring of updates waiting on the outstanding write */
WaitQueue currentUpdateWaiters;
/** Ring of updates waiting on the next write */
WaitQueue nextUpdateWaiters;
/** The active SlabSummaryEntry array for this block */
SlabSummaryEntry *entries;
/** The VIO used to write this block */
VIO *vio;
/** The packed entries, one block long, backing the VIO */
char *outgoingEntries;
} SlabSummaryBlock;
/**
* The statistics for all the slab summary zones owned by this slab summary.
* These fields are all mutated only by their physical zone threads, but are
* read by other threads when gathering statistics for the entire depot.
**/
typedef struct atomicSlabSummaryStatistics {
/** Number of blocks written */
Atomic64 blocksWritten;
} AtomicSlabSummaryStatistics;
struct slabSummaryZone {
/** The summary of which this is a zone */
SlabSummary *summary;
/** The number of this zone */
ZoneCount zoneNumber;
/** Count of the number of blocks currently out for writing */
BlockCount writeCount;
/** The state of this zone */
AdminState state;
/** The array (owned by the blocks) of all entries */
SlabSummaryEntry *entries;
/** The array of SlabSummaryEntryBlocks */
SlabSummaryBlock summaryBlocks[];
};
struct slabSummary {
/** The context for entering read-only mode */
ReadOnlyNotifier *readOnlyNotifier;
/** The statistics for this slab summary */
AtomicSlabSummaryStatistics statistics;
/** The start of the slab summary partition relative to the layer */
PhysicalBlockNumber origin;
/** The number of bits to shift to get a 7-bit fullness hint */
unsigned int hintShift;
/** The number of blocks (calculated based on MAX_SLABS) */
BlockCount blocksPerZone;
/** The number of slabs per block (calculated from block size) */
SlabCount entriesPerBlock;
/** The entries for all of the zones the partition can hold */
SlabSummaryEntry *entries;
/** The number of zones which were active at the time of the last update */
ZoneCount zonesToCombine;
/** The current number of active zones */
ZoneCount zoneCount;
/** The currently active zones */
SlabSummaryZone *zones[];
};
/**
* Treating the current entries buffer as the on-disk value of all zones,
* update every zone to the correct values for every slab.
*
* @param summary The summary whose entries should be combined
**/
void combineZones(SlabSummary *summary);
#endif // SLAB_SUMMARY_INTERNALS_H