#include "dm-exception-store.h"
+#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
}
EXPORT_SYMBOL(dm_exception_store_type_unregister);
-int dm_exception_store_create(const char *type_name, struct dm_target *ti,
- chunk_t chunk_size, chunk_t chunk_mask,
- chunk_t chunk_shift,
+static int set_chunk_size(struct dm_exception_store *store,
+ const char *chunk_size_arg, char **error)
+{
+ unsigned long chunk_size_ulong;
+ char *value;
+
+ chunk_size_ulong = simple_strtoul(chunk_size_arg, &value, 10);
+ if (*chunk_size_arg == '\0' || *value != '\0' ||
+ chunk_size_ulong > UINT_MAX) {
+ *error = "Invalid chunk size";
+ return -EINVAL;
+ }
+
+ if (!chunk_size_ulong) {
+ store->chunk_size = store->chunk_mask = store->chunk_shift = 0;
+ return 0;
+ }
+
+ return dm_exception_store_set_chunk_size(store,
+ (unsigned) chunk_size_ulong,
+ error);
+}
+
+int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
+ unsigned chunk_size,
+ char **error)
+{
+ /* Check chunk_size is a power of 2 */
+ if (!is_power_of_2(chunk_size)) {
+ *error = "Chunk size is not a power of 2";
+ return -EINVAL;
+ }
+
+ /* Validate the chunk size against the device block size */
+ if (chunk_size % (bdev_logical_block_size(store->cow->bdev) >> 9)) {
+ *error = "Chunk size is not a multiple of device blocksize";
+ return -EINVAL;
+ }
+
+ if (chunk_size > INT_MAX >> SECTOR_SHIFT) {
+ *error = "Chunk size is too high";
+ return -EINVAL;
+ }
+
+ store->chunk_size = chunk_size;
+ store->chunk_mask = chunk_size - 1;
+ store->chunk_shift = ffs(chunk_size) - 1;
+
+ return 0;
+}
+
+int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
+ unsigned *args_used,
struct dm_exception_store **store)
{
int r = 0;
- struct dm_exception_store_type *type;
+ struct dm_exception_store_type *type = NULL;
struct dm_exception_store *tmp_store;
+ char persistent;
+
+ if (argc < 3) {
+ ti->error = "Insufficient exception store arguments";
+ return -EINVAL;
+ }
tmp_store = kmalloc(sizeof(*tmp_store), GFP_KERNEL);
- if (!tmp_store)
+ if (!tmp_store) {
+ ti->error = "Exception store allocation failed";
return -ENOMEM;
+ }
+
+ persistent = toupper(*argv[1]);
+ if (persistent == 'P')
+ type = get_type("P");
+ else if (persistent == 'N')
+ type = get_type("N");
+ else {
+ ti->error = "Persistent flag is not P or N";
+ r = -EINVAL;
+ goto bad_type;
+ }
- type = get_type(type_name);
if (!type) {
- kfree(tmp_store);
- return -EINVAL;
+ ti->error = "Exception store type not recognised";
+ r = -EINVAL;
+ goto bad_type;
}
tmp_store->type = type;
tmp_store->ti = ti;
- tmp_store->chunk_size = chunk_size;
- tmp_store->chunk_mask = chunk_mask;
- tmp_store->chunk_shift = chunk_shift;
+ r = dm_get_device(ti, argv[0], 0, 0,
+ FMODE_READ | FMODE_WRITE, &tmp_store->cow);
+ if (r) {
+ ti->error = "Cannot get COW device";
+ goto bad_cow;
+ }
+
+ r = set_chunk_size(tmp_store, argv[2], &ti->error);
+ if (r)
+ goto bad_ctr;
r = type->ctr(tmp_store, 0, NULL);
if (r) {
- put_type(type);
- kfree(tmp_store);
- return r;
+ ti->error = "Exception store type constructor failed";
+ goto bad_ctr;
}
+ *args_used = 3;
*store = tmp_store;
return 0;
+
+bad_ctr:
+ dm_put_device(ti, tmp_store->cow);
+bad_cow:
+ put_type(type);
+bad_type:
+ kfree(tmp_store);
+ return r;
}
EXPORT_SYMBOL(dm_exception_store_create);
void dm_exception_store_destroy(struct dm_exception_store *store)
{
store->type->dtr(store);
+ dm_put_device(store->ti, store->cow);
put_type(store->type);
kfree(store);
}