123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318 |
- /*
- * Copyright (C) 2011 Red Hat, Inc.
- *
- * This file is released under the GPL.
- */
- #include "dm-space-map-common.h"
- #include "dm-space-map-disk.h"
- #include "dm-space-map.h"
- #include "dm-transaction-manager.h"
- #include <linux/list.h>
- #include <linux/slab.h>
- #include <linux/export.h>
- #include <linux/device-mapper.h>
- #define DM_MSG_PREFIX "space map disk"
- /*----------------------------------------------------------------*/
- /*
- * Space map interface.
- */
- struct sm_disk {
- struct dm_space_map sm;
- struct ll_disk ll;
- struct ll_disk old_ll;
- dm_block_t begin;
- dm_block_t nr_allocated_this_transaction;
- };
- static void sm_disk_destroy(struct dm_space_map *sm)
- {
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- kfree(smd);
- }
- static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
- {
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- return sm_ll_extend(&smd->ll, extra_blocks);
- }
- static int sm_disk_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
- {
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- *count = smd->old_ll.nr_blocks;
- return 0;
- }
- static int sm_disk_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
- {
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- *count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction;
- return 0;
- }
- static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,
- uint32_t *result)
- {
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- return sm_ll_lookup(&smd->ll, b, result);
- }
- static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,
- int *result)
- {
- int r;
- uint32_t count;
- r = sm_disk_get_count(sm, b, &count);
- if (r)
- return r;
- *result = count > 1;
- return 0;
- }
- static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
- uint32_t count)
- {
- int r;
- uint32_t old_count;
- enum allocation_event ev;
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- r = sm_ll_insert(&smd->ll, b, count, &ev);
- if (!r) {
- switch (ev) {
- case SM_NONE:
- break;
- case SM_ALLOC:
- /*
- * This _must_ be free in the prior transaction
- * otherwise we've lost atomicity.
- */
- smd->nr_allocated_this_transaction++;
- break;
- case SM_FREE:
- /*
- * It's only free if it's also free in the last
- * transaction.
- */
- r = sm_ll_lookup(&smd->old_ll, b, &old_count);
- if (r)
- return r;
- if (!old_count)
- smd->nr_allocated_this_transaction--;
- break;
- }
- }
- return r;
- }
- static int sm_disk_inc_block(struct dm_space_map *sm, dm_block_t b)
- {
- int r;
- enum allocation_event ev;
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- r = sm_ll_inc(&smd->ll, b, &ev);
- if (!r && (ev == SM_ALLOC))
- /*
- * This _must_ be free in the prior transaction
- * otherwise we've lost atomicity.
- */
- smd->nr_allocated_this_transaction++;
- return r;
- }
- static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b)
- {
- int r;
- uint32_t old_count;
- enum allocation_event ev;
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- r = sm_ll_dec(&smd->ll, b, &ev);
- if (!r && (ev == SM_FREE)) {
- /*
- * It's only free if it's also free in the last
- * transaction.
- */
- r = sm_ll_lookup(&smd->old_ll, b, &old_count);
- if (!r && !old_count)
- smd->nr_allocated_this_transaction--;
- }
- return r;
- }
- static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b)
- {
- int r;
- enum allocation_event ev;
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- /* FIXME: we should loop round a couple of times */
- r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b);
- if (r)
- return r;
- smd->begin = *b + 1;
- r = sm_ll_inc(&smd->ll, *b, &ev);
- if (!r) {
- BUG_ON(ev != SM_ALLOC);
- smd->nr_allocated_this_transaction++;
- }
- return r;
- }
- static int sm_disk_commit(struct dm_space_map *sm)
- {
- int r;
- dm_block_t nr_free;
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- r = sm_disk_get_nr_free(sm, &nr_free);
- if (r)
- return r;
- r = sm_ll_commit(&smd->ll);
- if (r)
- return r;
- memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
- smd->begin = 0;
- smd->nr_allocated_this_transaction = 0;
- r = sm_disk_get_nr_free(sm, &nr_free);
- if (r)
- return r;
- return 0;
- }
- static int sm_disk_root_size(struct dm_space_map *sm, size_t *result)
- {
- *result = sizeof(struct disk_sm_root);
- return 0;
- }
- static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
- {
- struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
- struct disk_sm_root root_le;
- root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
- root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
- root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
- root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root);
- if (max < sizeof(root_le))
- return -ENOSPC;
- memcpy(where_le, &root_le, sizeof(root_le));
- return 0;
- }
- /*----------------------------------------------------------------*/
- static struct dm_space_map ops = {
- .destroy = sm_disk_destroy,
- .extend = sm_disk_extend,
- .get_nr_blocks = sm_disk_get_nr_blocks,
- .get_nr_free = sm_disk_get_nr_free,
- .get_count = sm_disk_get_count,
- .count_is_more_than_one = sm_disk_count_is_more_than_one,
- .set_count = sm_disk_set_count,
- .inc_block = sm_disk_inc_block,
- .dec_block = sm_disk_dec_block,
- .new_block = sm_disk_new_block,
- .commit = sm_disk_commit,
- .root_size = sm_disk_root_size,
- .copy_root = sm_disk_copy_root,
- .register_threshold_callback = NULL
- };
- struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,
- dm_block_t nr_blocks)
- {
- int r;
- struct sm_disk *smd;
- smd = kmalloc(sizeof(*smd), GFP_KERNEL);
- if (!smd)
- return ERR_PTR(-ENOMEM);
- smd->begin = 0;
- smd->nr_allocated_this_transaction = 0;
- memcpy(&smd->sm, &ops, sizeof(smd->sm));
- r = sm_ll_new_disk(&smd->ll, tm);
- if (r)
- goto bad;
- r = sm_ll_extend(&smd->ll, nr_blocks);
- if (r)
- goto bad;
- r = sm_disk_commit(&smd->sm);
- if (r)
- goto bad;
- return &smd->sm;
- bad:
- kfree(smd);
- return ERR_PTR(r);
- }
- EXPORT_SYMBOL_GPL(dm_sm_disk_create);
- struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm,
- void *root_le, size_t len)
- {
- int r;
- struct sm_disk *smd;
- smd = kmalloc(sizeof(*smd), GFP_KERNEL);
- if (!smd)
- return ERR_PTR(-ENOMEM);
- smd->begin = 0;
- smd->nr_allocated_this_transaction = 0;
- memcpy(&smd->sm, &ops, sizeof(smd->sm));
- r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
- if (r)
- goto bad;
- r = sm_disk_commit(&smd->sm);
- if (r)
- goto bad;
- return &smd->sm;
- bad:
- kfree(smd);
- return ERR_PTR(r);
- }
- EXPORT_SYMBOL_GPL(dm_sm_disk_open);
- /*----------------------------------------------------------------*/
|