diff options
Diffstat (limited to 'drivers/md/persistent-data/dm-transaction-manager.h')
| -rw-r--r-- | drivers/md/persistent-data/dm-transaction-manager.h | 55 |
1 files changed, 39 insertions, 16 deletions
diff --git a/drivers/md/persistent-data/dm-transaction-manager.h b/drivers/md/persistent-data/dm-transaction-manager.h index b5b139076ca5..61a8d10825ca 100644 --- a/drivers/md/persistent-data/dm-transaction-manager.h +++ b/drivers/md/persistent-data/dm-transaction-manager.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2011 Red Hat, Inc. * @@ -38,18 +39,17 @@ struct dm_transaction_manager *dm_tm_create_non_blocking_clone(struct dm_transac /* * We use a 2-phase commit here. * - * i) In the first phase the block manager is told to start flushing, and - * the changes to the space map are written to disk. You should interrogate - * your particular space map to get detail of its root node etc. to be - * included in your superblock. + * i) Make all changes for the transaction *except* for the superblock. + * Then call dm_tm_pre_commit() to flush them to disk. * - * ii) @root will be committed last. You shouldn't use more than the - * first 512 bytes of @root if you wish the transaction to survive a power - * failure. You *must* have a write lock held on @root for both stage (i) - * and (ii). The commit will drop the write lock. + * ii) Lock your superblock. Update. Then call dm_tm_commit() which will + * unlock the superblock and flush it. No other blocks should be updated + * during this period. Care should be taken to never unlock a partially + * updated superblock; perform any operations that could fail *before* you + * take the superblock lock. */ int dm_tm_pre_commit(struct dm_transaction_manager *tm); -int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *root); +int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *superblock); /* * These methods are the only way to get hold of a writeable block. @@ -64,7 +64,7 @@ int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *root); * Zeroes the new block and returns with write lock held. */ int dm_tm_new_block(struct dm_transaction_manager *tm, - struct dm_block_validator *v, + const struct dm_block_validator *v, struct dm_block **result); /* @@ -84,7 +84,7 @@ int dm_tm_new_block(struct dm_transaction_manager *tm, * it locked when you call this. */ int dm_tm_shadow_block(struct dm_transaction_manager *tm, dm_block_t orig, - struct dm_block_validator *v, + const struct dm_block_validator *v, struct dm_block **result, int *inc_children); /* @@ -92,24 +92,47 @@ int dm_tm_shadow_block(struct dm_transaction_manager *tm, dm_block_t orig, * on it outstanding then it'll block. */ int dm_tm_read_lock(struct dm_transaction_manager *tm, dm_block_t b, - struct dm_block_validator *v, + const struct dm_block_validator *v, struct dm_block **result); -int dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b); +void dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b); /* * Functions for altering the reference count of a block directly. */ void dm_tm_inc(struct dm_transaction_manager *tm, dm_block_t b); - +void dm_tm_inc_range(struct dm_transaction_manager *tm, dm_block_t b, dm_block_t e); void dm_tm_dec(struct dm_transaction_manager *tm, dm_block_t b); +void dm_tm_dec_range(struct dm_transaction_manager *tm, dm_block_t b, dm_block_t e); + +/* + * Builds up runs of adjacent blocks, and then calls the given fn + * (typically dm_tm_inc/dec). Very useful when you have to perform + * the same tm operation on all values in a btree leaf. + */ +typedef void (*dm_tm_run_fn)(struct dm_transaction_manager *, dm_block_t, dm_block_t); +void dm_tm_with_runs(struct dm_transaction_manager *tm, + const __le64 *value_le, unsigned int count, dm_tm_run_fn fn); + +int dm_tm_ref(struct dm_transaction_manager *tm, dm_block_t b, uint32_t *result); -int dm_tm_ref(struct dm_transaction_manager *tm, dm_block_t b, - uint32_t *result); +/* + * Finds out if a given block is shared (ie. has a reference count higher + * than one). + */ +int dm_tm_block_is_shared(struct dm_transaction_manager *tm, dm_block_t b, + int *result); struct dm_block_manager *dm_tm_get_bm(struct dm_transaction_manager *tm); /* + * If you're using a non-blocking clone the tm will build up a list of + * requested blocks that weren't in core. This call will request those + * blocks to be prefetched. + */ +void dm_tm_issue_prefetches(struct dm_transaction_manager *tm); + +/* * A little utility that ties the knot by producing a transaction manager * that has a space map managed by the transaction manager... * |