md/dm-vdo/slab-depot.h

28  * A slab_depot is responsible for managing all of the slabs and block allocators of a VDO. It has
51  * Represents the possible status of a block.
54 	RS_FREE, /* this block is free */
55 	RS_SINGLE, /* this block is singly-referenced */
56 	RS_SHARED, /* this block is shared */
57 	RS_PROVISIONAL /* this block is provisionally allocated */
79 	/* Whether a tail block commit is pending */
88 	/* The oldest block in the journal on disk */
90 	/* The oldest block in the journal which may not be reaped */
94 	/* The next journal block to be committed */
105 	 * The number of entries which fit in a single block. Can't use the constant because unit
110 	 * The number of full entries which fit in a single block. Can't use the constant because
120 	/* A list of the VIO pool entries for outstanding journal block writes */
124 	 * The current tail block header state. This will be packed into the block just before it
128 	/* A pointer to a block-sized buffer holding the packed block data */
129 	struct packed_slab_journal_block *block;
145 	/* The lock for the oldest unreaped block of the journal */
147 	/* The locks for each on disk block */
157 	/* This block waits on the ref_counts to tell it to write */
161 	/* The number of references in this block that represent allocations */
163 	/* The slab journal block on which this block must hold a lock */
165 	/* The slab journal block which should be released when this block is committed */
169 	/* Whether this block has been modified since it was written to disk */
171 	/* Whether this block is currently writing */
175 /* The search_cursor represents the saved position of a free block search. */
177 	/* The reference block containing the current search index */
178 	struct reference_block *block;
181 	/* The position just past the last valid counter in the current block */
184 	/* A pointer to the first reference block in the slab */
186 	/* A pointer to the last reference block in the slab */
203  * A reference count is maintained for each physical block number. The vast majority of blocks have
219 	/* The offset in the allocator partition of the first block in this slab */
221 	/* The offset of the first block past the end of this slab */
246 	/* The saved block pointer and array indexes for the free block search */
262 	/* reference count block array */
320  * space will be used on restart), and the location of the tail block of the slab's journal.
343 	/* The block_allocator to which this block belongs */
345 	/* The index of this block in its zone's summary */
347 	/* Whether this block has a write outstanding */
353 	/* The active slab_summary_entry array for this block */
355 	/* The vio used to write this block */
357 	/* The packed entries, one block long, backing the vio */
410 	/* Statistics for this block allocator */
426 	/* The vio pool for reading and writing block allocator metadata */
486 	/* The last block before resize, for rollback */
488 	/* The last block after resize, for resize */
500 	/* The block allocators for this depot */