diff options
Diffstat (limited to 'drivers/md/persistent-data/dm-space-map-disk.c')
| -rw-r--r-- | drivers/md/persistent-data/dm-space-map-disk.c | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-space-map-disk.c b/drivers/md/persistent-data/dm-space-map-disk.c new file mode 100644 index 000000000..d0a8d5e73 --- /dev/null +++ b/drivers/md/persistent-data/dm-space-map-disk.c @@ -0,0 +1,280 @@ +/* + * 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; + int32_t nr_allocations; + struct sm_disk *smd = container_of(sm, struct sm_disk, sm); + + r = sm_ll_insert(&smd->ll, b, count, &nr_allocations); + if (!r) { + smd->nr_allocated_this_transaction += nr_allocations; + } + + return r; +} + +static int sm_disk_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e) +{ + int r; + int32_t nr_allocations; + struct sm_disk *smd = container_of(sm, struct sm_disk, sm); + + r = sm_ll_inc(&smd->ll, b, e, &nr_allocations); + if (!r) + smd->nr_allocated_this_transaction += nr_allocations; + + return r; +} + +static int sm_disk_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e) +{ + int r; + int32_t nr_allocations; + struct sm_disk *smd = container_of(sm, struct sm_disk, sm); + + r = sm_ll_dec(&smd->ll, b, e, &nr_allocations); + if (!r) + smd->nr_allocated_this_transaction += nr_allocations; + + return r; +} + +static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b) +{ + int r; + int32_t nr_allocations; + struct sm_disk *smd = container_of(sm, struct sm_disk, sm); + + /* + * Any block we allocate has to be free in both the old and current ll. + */ + r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, smd->begin, smd->ll.nr_blocks, b); + if (r == -ENOSPC) { + /* + * There's no free block between smd->begin and the end of the metadata device. + * We search before smd->begin in case something has been freed. + */ + r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, 0, smd->begin, b); + } + + if (r) + return r; + + smd->begin = *b + 1; + r = sm_ll_inc(&smd->ll, *b, *b + 1, &nr_allocations); + if (!r) { + smd->nr_allocated_this_transaction += nr_allocations; + } + + return r; +} + +static int sm_disk_commit(struct dm_space_map *sm) +{ + int r; + struct sm_disk *smd = container_of(sm, struct sm_disk, sm); + + r = sm_ll_commit(&smd->ll); + if (r) + return r; + + memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll)); + smd->nr_allocated_this_transaction = 0; + + 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_blocks = sm_disk_inc_blocks, + .dec_blocks = sm_disk_dec_blocks, + .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); + +/*----------------------------------------------------------------*/ |