+++ /dev/null
-#ifndef _BCACHE_STR_HASH_H
-#define _BCACHE_STR_HASH_H
-
-#include "btree_iter.h"
-#include "btree_update.h"
-#include "checksum.h"
-#include "error.h"
-#include "inode.h"
-#include "siphash.h"
-#include "super.h"
-
-#include <linux/crc32c.h>
-#include <crypto/hash.h>
-
-struct bch_hash_info {
- u8 type;
- union {
- __le64 crc_key;
- SIPHASH_KEY siphash_key;
- };
-};
-
-static inline struct bch_hash_info
-bch2_hash_info_init(struct bch_fs *c,
- const struct bch_inode_unpacked *bi)
-{
- /* XXX ick */
- struct bch_hash_info info = {
- .type = (bi->i_flags >> INODE_STR_HASH_OFFSET) &
- ~(~0U << INODE_STR_HASH_BITS)
- };
-
- switch (info.type) {
- case BCH_STR_HASH_CRC32C:
- case BCH_STR_HASH_CRC64:
- info.crc_key = bi->i_hash_seed;
- break;
- case BCH_STR_HASH_SIPHASH: {
- SHASH_DESC_ON_STACK(desc, c->sha256);
- u8 digest[crypto_shash_digestsize(c->sha256)];
-
- desc->tfm = c->sha256;
- desc->flags = 0;
-
- crypto_shash_digest(desc, (void *) &bi->i_hash_seed,
- sizeof(bi->i_hash_seed), digest);
- memcpy(&info.siphash_key, digest, sizeof(info.siphash_key));
- break;
- }
- default:
- BUG();
- }
-
- return info;
-}
-
-struct bch_str_hash_ctx {
- union {
- u32 crc32c;
- u64 crc64;
- SIPHASH_CTX siphash;
- };
-};
-
-static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx,
- const struct bch_hash_info *info)
-{
- switch (info->type) {
- case BCH_STR_HASH_CRC32C:
- ctx->crc32c = crc32c(~0, &info->crc_key, sizeof(info->crc_key));
- break;
- case BCH_STR_HASH_CRC64:
- ctx->crc64 = bch2_crc64_update(~0, &info->crc_key, sizeof(info->crc_key));
- break;
- case BCH_STR_HASH_SIPHASH:
- SipHash24_Init(&ctx->siphash, &info->siphash_key);
- break;
- default:
- BUG();
- }
-}
-
-static inline void bch2_str_hash_update(struct bch_str_hash_ctx *ctx,
- const struct bch_hash_info *info,
- const void *data, size_t len)
-{
- switch (info->type) {
- case BCH_STR_HASH_CRC32C:
- ctx->crc32c = crc32c(ctx->crc32c, data, len);
- break;
- case BCH_STR_HASH_CRC64:
- ctx->crc64 = bch2_crc64_update(ctx->crc64, data, len);
- break;
- case BCH_STR_HASH_SIPHASH:
- SipHash24_Update(&ctx->siphash, data, len);
- break;
- default:
- BUG();
- }
-}
-
-static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx,
- const struct bch_hash_info *info)
-{
- switch (info->type) {
- case BCH_STR_HASH_CRC32C:
- return ctx->crc32c;
- case BCH_STR_HASH_CRC64:
- return ctx->crc64 >> 1;
- case BCH_STR_HASH_SIPHASH:
- return SipHash24_End(&ctx->siphash) >> 1;
- default:
- BUG();
- }
-}
-
-struct bch_hash_desc {
- enum btree_id btree_id;
- u8 key_type;
- u8 whiteout_type;
-
- u64 (*hash_key)(const struct bch_hash_info *, const void *);
- u64 (*hash_bkey)(const struct bch_hash_info *, struct bkey_s_c);
- bool (*cmp_key)(struct bkey_s_c, const void *);
- bool (*cmp_bkey)(struct bkey_s_c, struct bkey_s_c);
-};
-
-static inline struct bkey_s_c
-bch2_hash_lookup_at(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct btree_iter *iter, const void *search)
-{
- u64 inode = iter->pos.inode;
-
- do {
- struct bkey_s_c k = bch2_btree_iter_peek_with_holes(iter);
-
- if (btree_iter_err(k))
- return k;
-
- if (k.k->type == desc.key_type) {
- if (!desc.cmp_key(k, search))
- return k;
- } else if (k.k->type == desc.whiteout_type) {
- ;
- } else {
- /* hole, not found */
- break;
- }
-
- bch2_btree_iter_advance_pos(iter);
- } while (iter->pos.inode == inode);
-
- return bkey_s_c_err(-ENOENT);
-}
-
-static inline struct bkey_s_c
-bch2_hash_lookup_bkey_at(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct btree_iter *iter, struct bkey_s_c search)
-{
- u64 inode = iter->pos.inode;
-
- do {
- struct bkey_s_c k = bch2_btree_iter_peek_with_holes(iter);
-
- if (btree_iter_err(k))
- return k;
-
- if (k.k->type == desc.key_type) {
- if (!desc.cmp_bkey(k, search))
- return k;
- } else if (k.k->type == desc.whiteout_type) {
- ;
- } else {
- /* hole, not found */
- break;
- }
-
- bch2_btree_iter_advance_pos(iter);
- } while (iter->pos.inode == inode);
-
- return bkey_s_c_err(-ENOENT);
-}
-
-static inline struct bkey_s_c
-bch2_hash_lookup(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct bch_fs *c, u64 inode,
- struct btree_iter *iter, const void *key)
-{
- bch2_btree_iter_init(iter, c, desc.btree_id,
- POS(inode, desc.hash_key(info, key)));
-
- return bch2_hash_lookup_at(desc, info, iter, key);
-}
-
-static inline struct bkey_s_c
-bch2_hash_lookup_intent(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct bch_fs *c, u64 inode,
- struct btree_iter *iter, const void *key)
-{
- bch2_btree_iter_init_intent(iter, c, desc.btree_id,
- POS(inode, desc.hash_key(info, key)));
-
- return bch2_hash_lookup_at(desc, info, iter, key);
-}
-
-static inline struct bkey_s_c
-bch2_hash_hole_at(const struct bch_hash_desc desc, struct btree_iter *iter)
-{
- while (1) {
- struct bkey_s_c k = bch2_btree_iter_peek_with_holes(iter);
-
- if (btree_iter_err(k))
- return k;
-
- if (k.k->type != desc.key_type)
- return k;
-
- /* hash collision, keep going */
- bch2_btree_iter_advance_pos(iter);
- if (iter->pos.inode != k.k->p.inode)
- return bkey_s_c_err(-ENOENT);
- }
-}
-
-static inline struct bkey_s_c bch2_hash_hole(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct bch_fs *c, u64 inode,
- struct btree_iter *iter,
- const void *key)
-{
- bch2_btree_iter_init_intent(iter, c, desc.btree_id,
- POS(inode, desc.hash_key(info, key)));
-
- return bch2_hash_hole_at(desc, iter);
-}
-
-static inline int bch2_hash_needs_whiteout(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct btree_iter *iter,
- struct btree_iter *start)
-{
- bch2_btree_iter_set_pos(iter,
- btree_type_successor(start->btree_id, start->pos));
-
- while (1) {
- struct bkey_s_c k = bch2_btree_iter_peek_with_holes(iter);
- int ret = btree_iter_err(k);
-
- if (ret)
- return ret;
-
- if (k.k->type != desc.key_type &&
- k.k->type != desc.whiteout_type)
- return false;
-
- if (k.k->type == desc.key_type &&
- desc.hash_bkey(info, k) <= start->pos.offset)
- return true;
-
- bch2_btree_iter_advance_pos(iter);
- }
-}
-
-#define BCH_HASH_SET_MUST_CREATE (1 << 4)
-#define BCH_HASH_SET_MUST_REPLACE (1 << 5)
-
-static inline int bch2_hash_set(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct bch_fs *c, u64 inode,
- u64 *journal_seq,
- struct bkey_i *insert, int flags)
-{
- struct btree_iter iter, hashed_slot;
- struct bkey_s_c k;
- int ret;
-
- bch2_btree_iter_init_intent(&hashed_slot, c, desc.btree_id,
- POS(inode, desc.hash_bkey(info, bkey_i_to_s_c(insert))));
- bch2_btree_iter_init_intent(&iter, c, desc.btree_id, hashed_slot.pos);
- bch2_btree_iter_link(&hashed_slot, &iter);
-retry:
- /*
- * On hash collision, we have to keep the slot we hashed to locked while
- * we do the insert - to avoid racing with another thread deleting
- * whatever's in the slot we hashed to:
- */
- ret = bch2_btree_iter_traverse(&hashed_slot);
- if (ret)
- goto err;
-
- /*
- * On -EINTR/retry, we dropped locks - always restart from the slot we
- * hashed to:
- */
- bch2_btree_iter_copy(&iter, &hashed_slot);
-
- k = bch2_hash_lookup_bkey_at(desc, info, &iter, bkey_i_to_s_c(insert));
-
- ret = btree_iter_err(k);
- if (ret == -ENOENT) {
- if (flags & BCH_HASH_SET_MUST_REPLACE) {
- ret = -ENOENT;
- goto err;
- }
-
- /*
- * Not found, so we're now looking for any open
- * slot - we might have skipped over a whiteout
- * that we could have used, so restart from the
- * slot we hashed to:
- */
- bch2_btree_iter_copy(&iter, &hashed_slot);
- k = bch2_hash_hole_at(desc, &iter);
- if ((ret = btree_iter_err(k)))
- goto err;
- } else if (!ret) {
- if (flags & BCH_HASH_SET_MUST_CREATE) {
- ret = -EEXIST;
- goto err;
- }
- } else {
- goto err;
- }
-
- insert->k.p = iter.pos;
- ret = bch2_btree_insert_at(c, NULL, NULL, journal_seq,
- BTREE_INSERT_ATOMIC|flags,
- BTREE_INSERT_ENTRY(&iter, insert));
-err:
- if (ret == -EINTR)
- goto retry;
-
- /*
- * On successful insert, we don't want to clobber ret with error from
- * iter:
- */
- bch2_btree_iter_unlock(&iter);
- bch2_btree_iter_unlock(&hashed_slot);
- return ret;
-}
-
-static inline int bch2_hash_delete_at(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct btree_iter *iter,
- u64 *journal_seq)
-{
- struct btree_iter whiteout_iter;
- struct bkey_i delete;
- int ret = -ENOENT;
-
- bch2_btree_iter_init(&whiteout_iter, iter->c, desc.btree_id,
- iter->pos);
- bch2_btree_iter_link(iter, &whiteout_iter);
-
- ret = bch2_hash_needs_whiteout(desc, info, &whiteout_iter, iter);
- if (ret < 0)
- goto err;
-
- bkey_init(&delete.k);
- delete.k.p = iter->pos;
- delete.k.type = ret ? desc.whiteout_type : KEY_TYPE_DELETED;
-
- ret = bch2_btree_insert_at(iter->c, NULL, NULL, journal_seq,
- BTREE_INSERT_NOFAIL|
- BTREE_INSERT_ATOMIC,
- BTREE_INSERT_ENTRY(iter, &delete));
-err:
- bch2_btree_iter_unlink(&whiteout_iter);
- return ret;
-}
-
-static inline int bch2_hash_delete(const struct bch_hash_desc desc,
- const struct bch_hash_info *info,
- struct bch_fs *c, u64 inode,
- u64 *journal_seq, const void *key)
-{
- struct btree_iter iter, whiteout_iter;
- struct bkey_s_c k;
- int ret = -ENOENT;
-
- bch2_btree_iter_init_intent(&iter, c, desc.btree_id,
- POS(inode, desc.hash_key(info, key)));
- bch2_btree_iter_init(&whiteout_iter, c, desc.btree_id,
- POS(inode, desc.hash_key(info, key)));
- bch2_btree_iter_link(&iter, &whiteout_iter);
-retry:
- k = bch2_hash_lookup_at(desc, info, &iter, key);
- if ((ret = btree_iter_err(k)))
- goto err;
-
- ret = bch2_hash_delete_at(desc, info, &iter, journal_seq);
-err:
- if (ret == -EINTR)
- goto retry;
-
- bch2_btree_iter_unlock(&whiteout_iter);
- bch2_btree_iter_unlock(&iter);
- return ret;
-}
-
-#endif /* _BCACHE_STR_HASH_H */
projects / bcachefs-tools-debian / blobdiff