int
flashcache_read_compute_checksum(struct cache_c *dmc, int index, void *block)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,27)
struct io_region where;
#else
struct dm_io_region where;
#endif
int error;
u_int64_t sum = 0, *idx;
int cnt;
where.bdev = dmc->cache_dev->bdev;
where.sector = INDEX_TO_CACHE_ADDR(dmc, index);
where.count = dmc->block_size;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,27)
error = flashcache_dm_io_sync_vm(dmc, &where, READ, block);
#else
error = flashcache_dm_io_sync_vm(dmc, &where, READ, block);
#endif
if (error)
return error;
cnt = dmc->block_size * 512;
idx = (u_int64_t *)block;
while (cnt > 0) {
sum += *idx++;
cnt -= sizeof(u_int64_t);
}
dmc->cache[index].checksum = sum;
return 0;
}
struct flashcache_copy_job *
new_flashcache_copy_job(struct cache_c *dmc,
int nr_writes,
struct dbn_index_pair *writes_list)
{
struct flashcache_copy_job *job;
int i, j;
job = alloc_flashcache_copy_job(dmc);
if (unlikely(job == NULL))
return NULL;
job->dmc = dmc;
job->nr_writes = nr_writes;
job->reads_completed = 0;
job->write_kickoff = 0;
job->error = 0;
job->pl_list_head = NULL;
for (i = 0 ; i < nr_writes ; i++) {
job->page_base[i] = alloc_page(GFP_NOIO);
if (unlikely(job->page_base[i] == NULL)) {
for (j = 0 ; j < i ; j++)
__free_page(job->page_base[j]);
goto nomem;
}
job->job_base[i] = new_kcached_job(dmc, NULL, writes_list[i].index);
atomic_inc(&dmc->nr_jobs);
if (unlikely(job->job_base[i] == NULL)) {
for (j = 0 ; j <= i ; j++)
__free_page(job->page_base[j]);
for (j = 0 ; j < i ; j++) {
flashcache_free_cache_job(job->job_base[i]);
if (atomic_dec_and_test(&dmc->nr_jobs))
wake_up(&dmc->destroyq);
}
goto nomem;
}
}
/*
* Stuff the pages into the page_list structures.
* Null terminate each page_list entry, because we want to do
* the individial reads first.
*/
for (i = 0 ; i < nr_writes ; i++) {
job->pl_base[i].next = NULL;
job->pl_base[i].page = job->page_base[i];
}
spin_lock_init(&job->copy_job_spinlock);
for (i = 0 ; i < nr_writes ; i++) {
job->job_io_regions.cache[i].bdev = dmc->cache_dev->bdev;
job->job_io_regions.cache[i].sector = INDEX_TO_CACHE_ADDR(dmc, writes_list[i].index);
job->job_io_regions.cache[i].count = dmc->block_size;
}
job->job_io_regions.disk.bdev = dmc->disk_dev->bdev;
job->job_io_regions.disk.sector = writes_list[0].dbn;
job->job_io_regions.disk.count = dmc->block_size * nr_writes;
return job;
nomem:
free_flashcache_copy_job(dmc, job);
return NULL;
}