The inram backend uses a simple in-memory hash table for storing
LBN-to-PBN and HASH-to-PBN mappings. We use linear probing to
resolve collisions.
Signed-off-by: Vasily Tarasov <tarasov@xxxxxxxxxxx>
---
drivers/md/dm-dedup-ram.c | 585 +++++++++++++++++++++++++++++++++++++++++++++
drivers/md/dm-dedup-ram.h | 43 ++++
2 files changed, 628 insertions(+), 0 deletions(-)
create mode 100644 drivers/md/dm-dedup-ram.c
create mode 100644 drivers/md/dm-dedup-ram.h
diff --git a/drivers/md/dm-dedup-ram.c b/drivers/md/dm-dedup-ram.c
new file mode 100644
index 0000000..36945ae
--- /dev/null
+++ b/drivers/md/dm-dedup-ram.c
@@ -0,0 +1,585 @@
+/*
+ * Copyright (C) 2012-2014 Vasily Tarasov
+ * Copyright (C) 2012-2014 Geoff Kuenning
+ * Copyright (C) 2012-2014 Sonam Mandal
+ * Copyright (C) 2012-2014 Karthikeyani Palanisami
+ * Copyright (C) 2012-2014 Philip Shilane
+ * Copyright (C) 2012-2014 Sagar Trehan
+ * Copyright (C) 2012-2014 Erez Zadok
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/errno.h>
+
+#include "dm-dedup-kvstore.h"
+#include "dm-dedup-ram.h"
+#include "dm-dedup-backend.h"
+
+#define EMPTY_ENTRY -5
+#define DELETED_ENTRY -6
+
+#define UINT32_MAX (4294967295U)
+#define HASHTABLE_OVERPROV (10)
+
+struct metadata {
+ /* Space Map */
+ uint32_t *smap;
+ uint64_t smax;
+ uint64_t allocptr;
+
+ /*
+ * XXX: Currently we support only one linear and one sparse KVS.
+ */
+ struct kvstore_inram *kvs_linear;
+ struct kvstore_inram *kvs_sparse;
+};
+
+struct kvstore_inram {
+ struct kvstore ckvs;
+ uint32_t kmax;
+ char *store;
+};
+
+static struct metadata *init_meta_inram(void *init_param, bool reconstruct)
+{
+ uint64_t smap_size;
+ struct metadata *md;
+ struct init_param_inram *p = (struct init_param_inram *)init_param;
+
+ DMINFO("Initializing INRAM backend");
+
+ if (reconstruct) {
+ DMERR("INRAM backend does not support reconstruction!");
+ return ERR_PTR(-ENOTSUPP);
+ }
+
+ md = kmalloc(sizeof(*md), GFP_NOIO);
+ if (!md)
+ return ERR_PTR(-ENOMEM);
+
+ smap_size = p->blocks * sizeof(uint32_t);
+
+ md->smap = vmalloc(smap_size);
+ if (!md->smap) {
+ kfree(md);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ DMINFO("Space allocated for pbn reference count map: %llu.%06llu MB\n",
+ smap_size / (1024 * 1024),
+ smap_size - ((smap_size /
+ (1024 * 1024)) * (1024 * 1024)));
+
+ memset(md->smap, 0, smap_size);
+
+ md->smax = p->blocks;
+ md->allocptr = 0;
+ md->kvs_linear = NULL;
+ md->kvs_sparse = NULL;
+
+ return md;
+}
+
+static void exit_meta_inram(struct metadata *md)
+{
+ if (md->smap)
+ vfree(md->smap);
+
+ if (md->kvs_linear) {
+ if (md->kvs_linear->store)
+ vfree(md->kvs_linear->store);
+ kfree(md->kvs_linear);
+ }
+
+ if (md->kvs_sparse) {
+ if (md->kvs_sparse->store)
+ vfree(md->kvs_sparse->store);
+ kfree(md->kvs_sparse);
+ }
+
+ kfree(md);
+
+ return;
+}
+
+
+static int flush_meta_inram(struct metadata *md)
+{
+ return 0;
+}
+
+/********************************************************
+ * Space Management Functions *
+ ********************************************************/
+
+static int alloc_data_block_inram(struct metadata *md, uint64_t *blockn)
+{
+ uint64_t head, tail;
+
+ head = tail = md->allocptr;
+
+ do {
+ if (!md->smap[head]) {
+ md->smap[head] = 1;
+ *blockn = head;
+ md->allocptr = (head + 1) % md->smax;
+ return 0;
+ }
+
+ head = (head + 1) % md->smax;
+
+ } while (head != tail);
+
+ return -ENOSPC;
+}
+
+static int inc_refcount_inram(struct metadata *md, uint64_t blockn)
+{
+ if (blockn >= md->smax)
+ return -ERANGE;
+
+ if (md->smap[blockn] != UINT32_MAX)
+ md->smap[blockn]++;
+ else
+ return -E2BIG;
+
+ return 0;
+}
+
+static int dec_refcount_inram(struct metadata *md, uint64_t blockn)
+{
+ if (blockn >= md->smax)
+ return -ERANGE;
+
+ if (md->smap[blockn])
+ md->smap[blockn]--;
+ else
+ return -EFAULT;
+
+ return 0;
+}
+
+static int get_refcount_inram(struct metadata *md, uint64_t blockn)
+{
+ if (blockn >= md->smax)
+ return -ERANGE;
+
+ return md->smap[blockn];
+}
+
+/********************************************************
+ * General KVS Functions *
+ ********************************************************/
+
+static int is_empty(char *ptr, int length)
+{
+ int i = 0;
+
+ while ((i < length) && (ptr[i] == EMPTY_ENTRY))
+ i++;
+
+ return i == length;
+}
+
+static int is_deleted(char *ptr, int length)
+{
+ int i = 0;
+
+ while ((i < length) && (ptr[i] == DELETED_ENTRY))
+ i++;
+
+ return i == length;
+}
+
+/*********************************************************
+ * Linear KVS Functions *
+ *********************************************************/
+
+static int kvs_delete_linear_inram(struct kvstore *kvs,
+ void *key, int32_t ksize)
+{
+ uint64_t idx;
+ char *ptr;
+ struct kvstore_inram *kvinram = NULL;
+
+ kvinram = container_of(kvs, struct kvstore_inram, ckvs);
+
+ if (ksize != kvs->ksize)
+ return -EINVAL;
+
+ idx = *((uint64_t *)key);
+
+ if (idx > kvinram->kmax)
+ return -ERANGE;
+
+ ptr = kvinram->store + kvs->vsize * idx;
+
+ if (is_empty(ptr, kvs->vsize))
+ return -ENODEV;
+
+ memset(ptr, EMPTY_ENTRY, kvs->vsize);
+
+ return 0;
+}
+
+/*
+ * 0 - not found
+ * 1 - found
+ * < 0 - error on lookup
+ */
+static int kvs_lookup_linear_inram(struct kvstore *kvs, void *key,
+ int32_t ksize, void *value, int32_t *vsize)
+{
+ uint64_t idx;
+ char *ptr;
+ struct kvstore_inram *kvinram = NULL;
+
+ kvinram = container_of(kvs, struct kvstore_inram, ckvs);
+
+ if (ksize != kvs->ksize)
+ return -EINVAL;
+
+ idx = *((uint64_t *)key);
+
+ if (idx > kvinram->kmax)
+ return -ERANGE;
+
+ ptr = kvinram->store + kvs->vsize * idx;
+
+ if (is_empty(ptr, kvs->vsize))
+ return 0;
+
+ memcpy(value, ptr, kvs->vsize);
+ *vsize = kvs->vsize;
+
+ return 1;
+}
+
+static int kvs_insert_linear_inram(struct kvstore *kvs, void *key,
+ int32_t ksize, void *value,
+ int32_t vsize)
+{
+ uint64_t idx;
+ char *ptr;
+ struct kvstore_inram *kvinram = NULL;
+
+ kvinram = container_of(kvs, struct kvstore_inram, ckvs);
+
+ if (ksize != kvs->ksize)
+ return -EINVAL;
+
+ if (vsize != kvs->vsize)
+ return -EINVAL;
+
+ idx = *((uint64_t *)key);
+
+ if (idx > kvinram->kmax)
+ return -ERANGE;
+
+ ptr = kvinram->store + kvs->vsize * idx;
+
+ memcpy(ptr, value, kvs->vsize);
+
+ return 0;
+}
+
+/*
+ * NOTE: if iteration_action() is a deletion/cleanup function,
+ * Make sure that the store is implemented such that
+ * deletion in-place is safe while iterating.
+ */
+static int kvs_iterate_linear_inram(struct kvstore *kvs,
+ int (*iteration_action)(void *key, int32_t ksize,
+ void *value, int32_t vsize, void *data), void *data)
+{
+ int ret = 0;
+ uint64_t i = 0;
+ char *ptr = NULL;
+ struct kvstore_inram *kvinram = NULL;
+
+ kvinram = container_of(kvs, struct kvstore_inram, ckvs);
+
+ for (i = 0; i < kvinram->kmax; i++) {
+ ptr = kvinram->store + (i * kvs->vsize);
+
+ ret = is_empty(ptr, kvs->vsize);
+
+ if (!ret) {
+ ret = iteration_action((void *)&i, kvs->ksize,
+ (void *)ptr, kvs->vsize, data);
+ if (ret < 0)
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+
+static struct kvstore *kvs_create_linear_inram(struct metadata *md,
+ uint32_t ksize, uint32_t vsize, uint32_t kmax,
+ bool reconstruct)
+{
+ struct kvstore_inram *kvs;
+ uint64_t kvstore_size;
+
+ if (!vsize || !ksize || !kmax)
+ return ERR_PTR(-ENOTSUPP);
+
+ /* Currently only 64bit keys are supported */
+ if (ksize != 8)
+ return ERR_PTR(-ENOTSUPP);
+
+ /* We do not support two or more KVSs at the moment */
+ if (md->kvs_linear)
+ return ERR_PTR(-EBUSY);
+
+ kvs = kmalloc(sizeof(*kvs), GFP_NOIO);
+ if (!kvs)
+ return ERR_PTR(-ENOMEM);
+
+ kvstore_size = (kmax + 1) * vsize;
+ kvs->store = vmalloc(kvstore_size);
+ if (!kvs->store) {
+ kfree(kvs);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ DMINFO("Space allocated for linear key value store: %llu.%06llu MB\n",
+ kvstore_size / (1024 * 1024),
+ kvstore_size - ((kvstore_size / (1024 * 1024))
+ * (1024 * 1024)));
+
+ memset(kvs->store, EMPTY_ENTRY, kvstore_size);
+
+ kvs->ckvs.vsize = vsize;
+ kvs->ckvs.ksize = ksize;
+ kvs->kmax = kmax;
+
+ kvs->ckvs.kvs_insert = kvs_insert_linear_inram;
+ kvs->ckvs.kvs_lookup = kvs_lookup_linear_inram;
+ kvs->ckvs.kvs_delete = kvs_delete_linear_inram;
+ kvs->ckvs.kvs_iterate = kvs_iterate_linear_inram;
+ md->kvs_linear = kvs;
+
+ return &(kvs->ckvs);
+}
+
+/********************************************************
+ * Sparse KVS Functions *
+ ********************************************************/
+
+static int kvs_delete_sparse_inram(struct kvstore *kvs,
+ void *key, int32_t ksize)
+{
+ uint64_t idxhead = *((uint64_t *)key);
+ uint32_t entry_size, head, tail;
+ char *ptr;
+ struct kvstore_inram *kvinram = NULL;
+
+ if (ksize != kvs->ksize)
+ return -EINVAL;
+
+ kvinram = container_of(kvs, struct kvstore_inram, ckvs);
+
+ entry_size = kvs->vsize + kvs->ksize;
+ head = idxhead % kvinram->kmax;
+ tail = head;
+
+ do {
+ ptr = kvinram->store + entry_size * head;
+
+ if (is_empty(ptr, entry_size))
+ goto doesnotexist;
+
+ if (memcmp(ptr, key, kvs->ksize))
+ head = (head + 1) % kvinram->kmax;
+ else {
+ memset(ptr, DELETED_ENTRY, entry_size);
+ return 0;
+ }
+ } while (head != tail);
+
+doesnotexist:
+ return -ENODEV;
+}
+
+/*
+ * 0 - not found
+ * 1 - found
+ * < 0 - error on lookup
+ */
+static int kvs_lookup_sparse_inram(struct kvstore *kvs, void *key,
+ int32_t ksize, void *value, int32_t *vsize)
+{
+ uint64_t idxhead = *((uint64_t *)key);
+ uint32_t entry_size, head, tail;
+ char *ptr;
+ struct kvstore_inram *kvinram = NULL;
+
+ if (ksize != kvs->ksize)
+ return -EINVAL;
+
+ kvinram = container_of(kvs, struct kvstore_inram, ckvs);
+
+ entry_size = kvs->vsize + kvs->ksize;
+ head = idxhead % kvinram->kmax;
+ tail = head;
+
+ do {
+ ptr = kvinram->store + entry_size * head;
+
+ if (is_empty(ptr, entry_size))
+ return 0;
+
+ if (memcmp(ptr, key, kvs->ksize))
+ head = (head + 1) % kvinram->kmax;
+ else {
+ memcpy(value, ptr + kvs->ksize, kvs->vsize);
+ return 1;
+ }
+
+ } while (head != tail);
+
+ return 0;
+}
+
+static int kvs_insert_sparse_inram(struct kvstore *kvs, void *key,
+ int32_t ksize, void *value, int32_t vsize)
+{
+ uint64_t idxhead = *((uint64_t *)key);
+ uint32_t entry_size, head, tail;
+ char *ptr;
+ struct kvstore_inram *kvinram = NULL;
+
+ BUG_ON(!kvs);
+ BUG_ON(ksize > kvs->ksize);
+
+ kvinram = container_of(kvs, struct kvstore_inram, ckvs);
+
+ entry_size = kvs->vsize + kvs->ksize;
+ head = idxhead % kvinram->kmax;
+ tail = head;
+
+ do {
+ ptr = kvinram->store + entry_size * head;
+
+ if (is_empty(ptr, entry_size) || is_deleted(ptr, entry_size)) {
+ memcpy(ptr, key, kvs->ksize);
+ memcpy(ptr + kvs->ksize, value, kvs->vsize);
+ return 0;
+ }
+
+ head = (head + 1) % kvinram->kmax;
+
+ } while (head != tail);
+
+ return -ENOSPC;
+}
+
+/*
+ *
+ * NOTE: if iteration_action() is a deletion/cleanup function,
+ * Make sure that the store is implemented such that
+ * deletion in-place is safe while iterating.
+ */
+static int kvs_iterate_sparse_inram(struct kvstore *kvs,
+ int (*iteration_action)(void *key, int32_t ksize,
+ void *value, int32_t vsize, void *data), void *data)
+{
+ int err = 0;
+ uint32_t kvalue_size, head = 0;
+ char *ptr = NULL;
+ struct kvstore_inram *kvinram = NULL;
+
+ BUG_ON(!kvs);
+
+ kvinram = container_of(kvs, struct kvstore_inram, ckvs);
+
+ kvalue_size = kvs->vsize + kvs->ksize;
+
+ do {
+ ptr = kvinram->store + (head * kvalue_size);
+
+ if (!is_empty(ptr, kvalue_size) &&
+ !is_deleted(ptr, kvalue_size)) {
+ err = iteration_action((void *)ptr, kvs->ksize,
+ (void *)(ptr + kvs->ksize),
+ kvs->vsize, data);
+
+ if (err < 0)
+ goto out;
+ }
+
+ head = (head + 1) % kvinram->kmax;
+ } while (head);
+
+out:
+ return err;
+}
+
+static struct kvstore *kvs_create_sparse_inram(struct metadata *md,
+ uint32_t ksize, uint32_t vsize, uint32_t knummax,
+ bool reconstruct)
+{
+ struct kvstore_inram *kvs;
+ uint64_t kvstore_size;
+
+ if (!vsize || !ksize || !knummax)
+ return ERR_PTR(-ENOTSUPP);
+
+ /* We do not support two or more KVSs at the moment */
+ if (md->kvs_sparse)
+ return ERR_PTR(-EBUSY);
+
+ kvs = kmalloc(sizeof(*kvs), GFP_NOIO);
+ if (!kvs)
+ return ERR_PTR(-ENOMEM);
+
+ knummax += knummax * HASHTABLE_OVERPROV / 100;
+
+ kvstore_size = (knummax * (vsize + ksize));
+
+ kvs->store = vmalloc(kvstore_size);
+ if (!kvs->store) {
+ kfree(kvs);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ DMINFO("Space allocated for sparse key value store: %llu.%06llu MB\n",
+ kvstore_size / (1024 * 1024),
+ kvstore_size - ((kvstore_size / (1024 * 1024))
+ * (1024 * 1024)));
+
+ memset(kvs->store, EMPTY_ENTRY, kvstore_size);
+
+ kvs->ckvs.vsize = vsize;
+ kvs->ckvs.ksize = ksize;
+ kvs->kmax = knummax;
+
+ kvs->ckvs.kvs_insert = kvs_insert_sparse_inram;
+ kvs->ckvs.kvs_lookup = kvs_lookup_sparse_inram;
+ kvs->ckvs.kvs_delete = kvs_delete_sparse_inram;
+ kvs->ckvs.kvs_iterate = kvs_iterate_sparse_inram;
+
+ md->kvs_sparse = kvs;
+
+ return &(kvs->ckvs);
+}
+
+struct metadata_ops metadata_ops_inram = {
+ .init_meta = init_meta_inram,
+ .exit_meta = exit_meta_inram,
+ .kvs_create_linear = kvs_create_linear_inram,
+ .kvs_create_sparse = kvs_create_sparse_inram,
+
+ .alloc_data_block = alloc_data_block_inram,
+ .inc_refcount = inc_refcount_inram,
+ .dec_refcount = dec_refcount_inram,
+ .get_refcount = get_refcount_inram,
+
+ .flush_meta = flush_meta_inram,
+
+ .flush_bufio_cache = NULL,
+};
diff --git a/drivers/md/dm-dedup-ram.h b/drivers/md/dm-dedup-ram.h
new file mode 100644
index 0000000..851b92f
--- /dev/null
+++ b/drivers/md/dm-dedup-ram.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2012-2014 Vasily Tarasov
+ * Copyright (C) 2012-2014 Geoff Kuenning
+ * Copyright (C) 2012-2014 Sonam Mandal
+ * Copyright (C) 2012-2014 Karthikeyani Palanisami
+ * Copyright (C) 2012-2014 Philip Shilane
+ * Copyright (C) 2012-2014 Sagar Trehan
+ * Copyright (C) 2012-2014 Erez Zadok
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef INRAM_BACKEND_H
+#define INRAM_BACKEND_H
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/device-mapper.h>
+#include <linux/dm-io.h>
+#include <linux/dm-kcopyd.h>
+#include <linux/list.h>
+#include <linux/err.h>
+#include <asm/current.h>
+#include <linux/string.h>
+#include <linux/gfp.h>
+
+#include <linux/scatterlist.h>
+#include <asm/page.h>
+#include <asm/unaligned.h>
+#include <crypto/hash.h>
+#include <crypto/md5.h>
+#include <crypto/algapi.h>
+
+#include "dm-dedup-target.h"
+
+extern struct metadata_ops metadata_ops_inram;
+
+struct init_param_inram {
+ uint64_t blocks;
+};
+
+#endif /* INRAM_BACKEND_H */
--
1.7.1
--
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