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author | Jakub Kicinski <kuba@kernel.org> | 2024-03-22 02:14:13 +0300 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2024-03-22 02:15:08 +0300 |
commit | 537c2e91d3549e5d6020bb0576cf9b54a845255f (patch) | |
tree | c09e8a1b7d733cde19b0c72678c28fb2bc97ff6b /drivers/md/dm-vdo/packer.h | |
parent | 237bb5f7f7f55ec5f773469a974c61a49c298625 (diff) | |
parent | cba9ffdb9913dfe6be29f049ce920ce451ce7cc4 (diff) | |
download | linux-537c2e91d3549e5d6020bb0576cf9b54a845255f.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/md/dm-vdo/packer.h')
-rw-r--r-- | drivers/md/dm-vdo/packer.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/packer.h b/drivers/md/dm-vdo/packer.h new file mode 100644 index 000000000000..0f3be44710b5 --- /dev/null +++ b/drivers/md/dm-vdo/packer.h @@ -0,0 +1,122 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2023 Red Hat + */ + +#ifndef VDO_PACKER_H +#define VDO_PACKER_H + +#include <linux/list.h> + +#include "admin-state.h" +#include "constants.h" +#include "encodings.h" +#include "statistics.h" +#include "types.h" +#include "wait-queue.h" + +enum { + DEFAULT_PACKER_BINS = 16, +}; + +/* The header of a compressed block. */ +struct compressed_block_header { + /* Unsigned 32-bit major and minor versions, little-endian */ + struct packed_version_number version; + + /* List of unsigned 16-bit compressed block sizes, little-endian */ + __le16 sizes[VDO_MAX_COMPRESSION_SLOTS]; +} __packed; + +enum { + VDO_COMPRESSED_BLOCK_DATA_SIZE = VDO_BLOCK_SIZE - sizeof(struct compressed_block_header), + + /* + * A compressed block is only written if we can pack at least two fragments into it, so a + * fragment which fills the entire data portion of a compressed block is too big. + */ + VDO_MAX_COMPRESSED_FRAGMENT_SIZE = VDO_COMPRESSED_BLOCK_DATA_SIZE - 1, +}; + +/* * The compressed block overlay. */ +struct compressed_block { + struct compressed_block_header header; + char data[VDO_COMPRESSED_BLOCK_DATA_SIZE]; +} __packed; + +/* + * Each packer_bin holds an incomplete batch of data_vios that only partially fill a compressed + * block. The bins are kept in a ring sorted by the amount of unused space so the first bin with + * enough space to hold a newly-compressed data_vio can easily be found. When the bin fills up or + * is flushed, the first uncanceled data_vio in the bin is selected to be the agent for that bin. + * Upon entering the packer, each data_vio already has its compressed data in the first slot of the + * data_vio's compressed_block (overlaid on the data_vio's scratch_block). So the agent's fragment + * is already in place. The fragments for the other uncanceled data_vios in the bin are packed into + * the agent's compressed block. The agent then writes out the compressed block. If the write is + * successful, the agent shares its pbn lock which each of the other data_vios in its compressed + * block and sends each on its way. Finally the agent itself continues on the write path as before. + * + * There is one special bin which is used to hold data_vios which have been canceled and removed + * from their bin by the packer. These data_vios need to wait for the canceller to rendezvous with + * them and so they sit in this special bin. + */ +struct packer_bin { + /* List links for packer.packer_bins */ + struct list_head list; + /* The number of items in the bin */ + slot_number_t slots_used; + /* The number of compressed block bytes remaining in the current batch */ + size_t free_space; + /* The current partial batch of data_vios, waiting for more */ + struct data_vio *incoming[]; +}; + +struct packer { + /* The ID of the packer's callback thread */ + thread_id_t thread_id; + /* The number of bins */ + block_count_t size; + /* A list of all packer_bins, kept sorted by free_space */ + struct list_head bins; + /* + * A bin to hold data_vios which were canceled out of the packer and are waiting to + * rendezvous with the canceling data_vio. + */ + struct packer_bin *canceled_bin; + + /* The current flush generation */ + sequence_number_t flush_generation; + + /* The administrative state of the packer */ + struct admin_state state; + + /* Statistics are only updated on the packer thread, but are accessed from other threads */ + struct packer_statistics statistics; +}; + +int vdo_get_compressed_block_fragment(enum block_mapping_state mapping_state, + struct compressed_block *block, + u16 *fragment_offset, u16 *fragment_size); + +int __must_check vdo_make_packer(struct vdo *vdo, block_count_t bin_count, + struct packer **packer_ptr); + +void vdo_free_packer(struct packer *packer); + +struct packer_statistics __must_check vdo_get_packer_statistics(const struct packer *packer); + +void vdo_attempt_packing(struct data_vio *data_vio); + +void vdo_flush_packer(struct packer *packer); + +void vdo_remove_lock_holder_from_packer(struct vdo_completion *completion); + +void vdo_increment_packer_flush_generation(struct packer *packer); + +void vdo_drain_packer(struct packer *packer, struct vdo_completion *completion); + +void vdo_resume_packer(struct packer *packer, struct vdo_completion *parent); + +void vdo_dump_packer(const struct packer *packer); + +#endif /* VDO_PACKER_H */ |