diff options
Diffstat (limited to 'drivers/md/persistent-data/dm-space-map-checker.c')
| -rw-r--r-- | drivers/md/persistent-data/dm-space-map-checker.c | 437 |
1 files changed, 437 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-space-map-checker.c b/drivers/md/persistent-data/dm-space-map-checker.c new file mode 100644 index 000000000000..bb44a937fe63 --- /dev/null +++ b/drivers/md/persistent-data/dm-space-map-checker.c @@ -0,0 +1,437 @@ +/* + * Copyright (C) 2011 Red Hat, Inc. + * + * This file is released under the GPL. + */ + +#include "dm-space-map-checker.h" + +#include <linux/device-mapper.h> + +#ifdef CONFIG_DM_DEBUG_SPACE_MAPS + +#define DM_MSG_PREFIX "space map checker" + +/*----------------------------------------------------------------*/ + +struct count_array { + dm_block_t nr; + dm_block_t nr_free; + + uint32_t *counts; +}; + +static int ca_get_count(struct count_array *ca, dm_block_t b, uint32_t *count) +{ + if (b >= ca->nr) + return -EINVAL; + + *count = ca->counts[b]; + return 0; +} + +static int ca_count_more_than_one(struct count_array *ca, dm_block_t b, int *r) +{ + if (b >= ca->nr) + return -EINVAL; + + *r = ca->counts[b] > 1; + return 0; +} + +static int ca_set_count(struct count_array *ca, dm_block_t b, uint32_t count) +{ + uint32_t old_count; + + if (b >= ca->nr) + return -EINVAL; + + old_count = ca->counts[b]; + + if (!count && old_count) + ca->nr_free++; + + else if (count && !old_count) + ca->nr_free--; + + ca->counts[b] = count; + return 0; +} + +static int ca_inc_block(struct count_array *ca, dm_block_t b) +{ + if (b >= ca->nr) + return -EINVAL; + + ca_set_count(ca, b, ca->counts[b] + 1); + return 0; +} + +static int ca_dec_block(struct count_array *ca, dm_block_t b) +{ + if (b >= ca->nr) + return -EINVAL; + + BUG_ON(ca->counts[b] == 0); + ca_set_count(ca, b, ca->counts[b] - 1); + return 0; +} + +static int ca_create(struct count_array *ca, struct dm_space_map *sm) +{ + int r; + dm_block_t nr_blocks; + + r = dm_sm_get_nr_blocks(sm, &nr_blocks); + if (r) + return r; + + ca->nr = nr_blocks; + ca->nr_free = nr_blocks; + ca->counts = kzalloc(sizeof(*ca->counts) * nr_blocks, GFP_KERNEL); + if (!ca->counts) + return -ENOMEM; + + return 0; +} + +static int ca_load(struct count_array *ca, struct dm_space_map *sm) +{ + int r; + uint32_t count; + dm_block_t nr_blocks, i; + + r = dm_sm_get_nr_blocks(sm, &nr_blocks); + if (r) + return r; + + BUG_ON(ca->nr != nr_blocks); + + DMWARN("Loading debug space map from disk. This may take some time"); + for (i = 0; i < nr_blocks; i++) { + r = dm_sm_get_count(sm, i, &count); + if (r) { + DMERR("load failed"); + return r; + } + + ca_set_count(ca, i, count); + } + DMWARN("Load complete"); + + return 0; +} + +static int ca_extend(struct count_array *ca, dm_block_t extra_blocks) +{ + dm_block_t nr_blocks = ca->nr + extra_blocks; + uint32_t *counts = kzalloc(sizeof(*counts) * nr_blocks, GFP_KERNEL); + if (!counts) + return -ENOMEM; + + memcpy(counts, ca->counts, sizeof(*counts) * ca->nr); + kfree(ca->counts); + ca->nr = nr_blocks; + ca->nr_free += extra_blocks; + ca->counts = counts; + return 0; +} + +static int ca_commit(struct count_array *old, struct count_array *new) +{ + if (old->nr != new->nr) { + BUG_ON(old->nr > new->nr); + ca_extend(old, new->nr - old->nr); + } + + BUG_ON(old->nr != new->nr); + old->nr_free = new->nr_free; + memcpy(old->counts, new->counts, sizeof(*old->counts) * old->nr); + return 0; +} + +static void ca_destroy(struct count_array *ca) +{ + kfree(ca->counts); +} + +/*----------------------------------------------------------------*/ + +struct sm_checker { + struct dm_space_map sm; + + struct count_array old_counts; + struct count_array counts; + + struct dm_space_map *real_sm; +}; + +static void sm_checker_destroy(struct dm_space_map *sm) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + + dm_sm_destroy(smc->real_sm); + ca_destroy(&smc->old_counts); + ca_destroy(&smc->counts); + kfree(smc); +} + +static int sm_checker_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + int r = dm_sm_get_nr_blocks(smc->real_sm, count); + if (!r) + BUG_ON(smc->old_counts.nr != *count); + return r; +} + +static int sm_checker_get_nr_free(struct dm_space_map *sm, dm_block_t *count) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + int r = dm_sm_get_nr_free(smc->real_sm, count); + if (!r) { + /* + * Slow, but we know it's correct. + */ + dm_block_t b, n = 0; + for (b = 0; b < smc->old_counts.nr; b++) + if (smc->old_counts.counts[b] == 0 && + smc->counts.counts[b] == 0) + n++; + + if (n != *count) + DMERR("free block counts differ, checker %u, sm-disk:%u", + (unsigned) n, (unsigned) *count); + } + return r; +} + +static int sm_checker_new_block(struct dm_space_map *sm, dm_block_t *b) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + int r = dm_sm_new_block(smc->real_sm, b); + + if (!r) { + BUG_ON(*b >= smc->old_counts.nr); + BUG_ON(smc->old_counts.counts[*b] != 0); + BUG_ON(*b >= smc->counts.nr); + BUG_ON(smc->counts.counts[*b] != 0); + ca_set_count(&smc->counts, *b, 1); + } + + return r; +} + +static int sm_checker_inc_block(struct dm_space_map *sm, dm_block_t b) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + int r = dm_sm_inc_block(smc->real_sm, b); + int r2 = ca_inc_block(&smc->counts, b); + BUG_ON(r != r2); + return r; +} + +static int sm_checker_dec_block(struct dm_space_map *sm, dm_block_t b) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + int r = dm_sm_dec_block(smc->real_sm, b); + int r2 = ca_dec_block(&smc->counts, b); + BUG_ON(r != r2); + return r; +} + +static int sm_checker_get_count(struct dm_space_map *sm, dm_block_t b, uint32_t *result) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + uint32_t result2 = 0; + int r = dm_sm_get_count(smc->real_sm, b, result); + int r2 = ca_get_count(&smc->counts, b, &result2); + + BUG_ON(r != r2); + if (!r) + BUG_ON(*result != result2); + return r; +} + +static int sm_checker_count_more_than_one(struct dm_space_map *sm, dm_block_t b, int *result) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + int result2 = 0; + int r = dm_sm_count_is_more_than_one(smc->real_sm, b, result); + int r2 = ca_count_more_than_one(&smc->counts, b, &result2); + + BUG_ON(r != r2); + if (!r) + BUG_ON(!(*result) && result2); + return r; +} + +static int sm_checker_set_count(struct dm_space_map *sm, dm_block_t b, uint32_t count) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + uint32_t old_rc; + int r = dm_sm_set_count(smc->real_sm, b, count); + int r2; + + BUG_ON(b >= smc->counts.nr); + old_rc = smc->counts.counts[b]; + r2 = ca_set_count(&smc->counts, b, count); + BUG_ON(r != r2); + + return r; +} + +static int sm_checker_commit(struct dm_space_map *sm) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + int r; + + r = dm_sm_commit(smc->real_sm); + if (r) + return r; + + r = ca_commit(&smc->old_counts, &smc->counts); + if (r) + return r; + + return 0; +} + +static int sm_checker_extend(struct dm_space_map *sm, dm_block_t extra_blocks) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + int r = dm_sm_extend(smc->real_sm, extra_blocks); + if (r) + return r; + + return ca_extend(&smc->counts, extra_blocks); +} + +static int sm_checker_root_size(struct dm_space_map *sm, size_t *result) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + return dm_sm_root_size(smc->real_sm, result); +} + +static int sm_checker_copy_root(struct dm_space_map *sm, void *copy_to_here_le, size_t len) +{ + struct sm_checker *smc = container_of(sm, struct sm_checker, sm); + return dm_sm_copy_root(smc->real_sm, copy_to_here_le, len); +} + +/*----------------------------------------------------------------*/ + +static struct dm_space_map ops_ = { + .destroy = sm_checker_destroy, + .get_nr_blocks = sm_checker_get_nr_blocks, + .get_nr_free = sm_checker_get_nr_free, + .inc_block = sm_checker_inc_block, + .dec_block = sm_checker_dec_block, + .new_block = sm_checker_new_block, + .get_count = sm_checker_get_count, + .count_is_more_than_one = sm_checker_count_more_than_one, + .set_count = sm_checker_set_count, + .commit = sm_checker_commit, + .extend = sm_checker_extend, + .root_size = sm_checker_root_size, + .copy_root = sm_checker_copy_root +}; + +struct dm_space_map *dm_sm_checker_create(struct dm_space_map *sm) +{ + int r; + struct sm_checker *smc; + + if (!sm) + return NULL; + + smc = kmalloc(sizeof(*smc), GFP_KERNEL); + if (!smc) + return NULL; + + memcpy(&smc->sm, &ops_, sizeof(smc->sm)); + r = ca_create(&smc->old_counts, sm); + if (r) { + kfree(smc); + return NULL; + } + + r = ca_create(&smc->counts, sm); + if (r) { + ca_destroy(&smc->old_counts); + kfree(smc); + return NULL; + } + + smc->real_sm = sm; + + r = ca_load(&smc->counts, sm); + if (r) { + ca_destroy(&smc->counts); + ca_destroy(&smc->old_counts); + kfree(smc); + return NULL; + } + + r = ca_commit(&smc->old_counts, &smc->counts); + if (r) { + ca_destroy(&smc->counts); + ca_destroy(&smc->old_counts); + kfree(smc); + return NULL; + } + + return &smc->sm; +} +EXPORT_SYMBOL_GPL(dm_sm_checker_create); + +struct dm_space_map *dm_sm_checker_create_fresh(struct dm_space_map *sm) +{ + int r; + struct sm_checker *smc; + + if (!sm) + return NULL; + + smc = kmalloc(sizeof(*smc), GFP_KERNEL); + if (!smc) + return NULL; + + memcpy(&smc->sm, &ops_, sizeof(smc->sm)); + r = ca_create(&smc->old_counts, sm); + if (r) { + kfree(smc); + return NULL; + } + + r = ca_create(&smc->counts, sm); + if (r) { + ca_destroy(&smc->old_counts); + kfree(smc); + return NULL; + } + + smc->real_sm = sm; + return &smc->sm; +} +EXPORT_SYMBOL_GPL(dm_sm_checker_create_fresh); + +/*----------------------------------------------------------------*/ + +#else + +struct dm_space_map *dm_sm_checker_create(struct dm_space_map *sm) +{ + return sm; +} +EXPORT_SYMBOL_GPL(dm_sm_checker_create); + +struct dm_space_map *dm_sm_checker_create_fresh(struct dm_space_map *sm) +{ + return sm; +} +EXPORT_SYMBOL_GPL(dm_sm_checker_create_fresh); + +/*----------------------------------------------------------------*/ + +#endif |