dm exception store: move cow pointer
Move COW device from snapshot to exception store.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 59c949b..2078b92 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -139,7 +139,7 @@
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,
+ chunk_t chunk_shift, struct dm_dev *cow,
struct dm_exception_store **store)
{
int r = 0;
@@ -163,6 +163,8 @@
tmp_store->chunk_mask = chunk_mask;
tmp_store->chunk_shift = chunk_shift;
+ tmp_store->cow = cow;
+
r = type->ctr(tmp_store, 0, NULL);
if (r) {
put_type(type);
diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h
index 449a1e4..4dbf357 100644
--- a/drivers/md/dm-exception-store.h
+++ b/drivers/md/dm-exception-store.h
@@ -99,6 +99,8 @@
struct dm_snapshot *snap;
+ struct dm_dev *cow;
+
/* Size of data blocks saved - must be a power of 2 */
chunk_t chunk_size;
chunk_t chunk_mask;
@@ -155,7 +157,7 @@
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,
+ chunk_t chunk_shift, struct dm_dev *cow,
struct dm_exception_store **store);
void dm_exception_store_destroy(struct dm_exception_store *store);
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index c3c5815..505afac 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -189,7 +189,7 @@
static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
{
struct dm_io_region where = {
- .bdev = ps->snap->cow->bdev,
+ .bdev = ps->snap->store->cow->bdev,
.sector = ps->snap->store->chunk_size * chunk,
.count = ps->snap->store->chunk_size,
};
@@ -253,7 +253,7 @@
static int zero_disk_area(struct pstore *ps, chunk_t area)
{
struct dm_io_region where = {
- .bdev = ps->snap->cow->bdev,
+ .bdev = ps->snap->store->cow->bdev,
.sector = ps->snap->store->chunk_size * area_location(ps, area),
.count = ps->snap->store->chunk_size,
};
@@ -280,7 +280,7 @@
*/
if (!ps->snap->store->chunk_size) {
ps->snap->store->chunk_size = max(DM_CHUNK_SIZE_DEFAULT_SECTORS,
- bdev_hardsect_size(ps->snap->cow->bdev) >> 9);
+ bdev_hardsect_size(ps->snap->store->cow->bdev) >> 9);
ps->snap->store->chunk_mask = ps->snap->store->chunk_size - 1;
ps->snap->store->chunk_shift = ffs(ps->snap->store->chunk_size)
- 1;
@@ -476,7 +476,7 @@
sector_t *numerator, sector_t *denominator)
{
*numerator = get_info(store)->next_free * store->chunk_size;
- *denominator = get_dev_size(store->snap->cow->bdev);
+ *denominator = get_dev_size(store->cow->bdev);
}
static void persistent_dtr(struct dm_exception_store *store)
@@ -565,7 +565,7 @@
struct pstore *ps = get_info(store);
uint32_t stride;
chunk_t next_free;
- sector_t size = get_dev_size(store->snap->cow->bdev);
+ sector_t size = get_dev_size(store->cow->bdev);
/* Is there enough room ? */
if (size < ((ps->next_free + 1) * store->chunk_size))
diff --git a/drivers/md/dm-snap-transient.c b/drivers/md/dm-snap-transient.c
index c542aba..77f58be 100644
--- a/drivers/md/dm-snap-transient.c
+++ b/drivers/md/dm-snap-transient.c
@@ -40,7 +40,7 @@
struct dm_snap_exception *e)
{
struct transient_c *tc = store->context;
- sector_t size = get_dev_size(store->snap->cow->bdev);
+ sector_t size = get_dev_size(store->cow->bdev);
if (size < (tc->next_free + store->chunk_size))
return -1;
@@ -64,7 +64,7 @@
sector_t *numerator, sector_t *denominator)
{
*numerator = ((struct transient_c *) store->context)->next_free;
- *denominator = get_dev_size(store->snap->cow->bdev);
+ *denominator = get_dev_size(store->cow->bdev);
}
static int transient_ctr(struct dm_exception_store *store,
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 7a90fed..5c067ef 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -468,7 +468,8 @@
/*
* Allocate room for a suitable hash table.
*/
-static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift)
+static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift,
+ struct dm_dev *cow)
{
sector_t hash_size, cow_dev_size, origin_dev_size, max_buckets;
@@ -476,7 +477,7 @@
* Calculate based on the size of the original volume or
* the COW volume...
*/
- cow_dev_size = get_dev_size(s->cow->bdev);
+ cow_dev_size = get_dev_size(cow->bdev);
origin_dev_size = get_dev_size(s->origin->bdev);
max_buckets = calc_max_buckets();
@@ -516,7 +517,8 @@
static int set_chunk_size(struct dm_snapshot *s, const char *chunk_size_arg,
chunk_t *chunk_size, chunk_t *chunk_mask,
- chunk_t *chunk_shift, char **error)
+ chunk_t *chunk_shift, struct dm_dev *cow,
+ char **error)
{
unsigned long chunk_size_ulong;
char *value;
@@ -545,7 +547,7 @@
}
/* Validate the chunk size against the device block size */
- if (chunk_size_ulong % (bdev_hardsect_size(s->cow->bdev) >> 9)) {
+ if (chunk_size_ulong % (bdev_hardsect_size(cow->bdev) >> 9)) {
*error = "Chunk size is not a multiple of device blocksize";
return -EINVAL;
}
@@ -569,6 +571,7 @@
char *origin_path;
char *cow_path;
chunk_t chunk_size, chunk_mask, chunk_shift;
+ struct dm_dev *cow;
if (argc != 4) {
ti->error = "requires exactly 4 arguments";
@@ -601,7 +604,7 @@
}
r = dm_get_device(ti, cow_path, 0, 0,
- FMODE_READ | FMODE_WRITE, &s->cow);
+ FMODE_READ | FMODE_WRITE, &cow);
if (r) {
dm_put_device(ti, s->origin);
ti->error = "Cannot get COW device";
@@ -609,7 +612,7 @@
}
r = set_chunk_size(s, argv[3], &chunk_size, &chunk_mask, &chunk_shift,
- &ti->error);
+ cow, &ti->error);
if (r)
goto bad3;
@@ -620,14 +623,14 @@
spin_lock_init(&s->pe_lock);
/* Allocate hash table for COW data */
- if (init_hash_tables(s, chunk_shift)) {
+ if (init_hash_tables(s, chunk_shift, cow)) {
ti->error = "Unable to allocate hash table space";
r = -ENOMEM;
goto bad3;
}
r = dm_exception_store_create(argv[2], ti, chunk_size, chunk_mask,
- chunk_shift, &s->store);
+ chunk_shift, cow, &s->store);
if (r) {
ti->error = "Couldn't create exception store";
r = -EINVAL;
@@ -705,7 +708,7 @@
exit_exception_table(&s->complete, exception_cache);
bad3:
- dm_put_device(ti, s->cow);
+ dm_put_device(ti, cow);
dm_put_device(ti, s->origin);
bad2:
@@ -732,6 +735,7 @@
int i;
#endif
struct dm_snapshot *s = ti->private;
+ struct dm_dev *cow = s->store->cow;
flush_workqueue(ksnapd);
@@ -759,7 +763,7 @@
mempool_destroy(s->pending_pool);
dm_put_device(ti, s->origin);
- dm_put_device(ti, s->cow);
+ dm_put_device(ti, cow);
kfree(s);
}
@@ -961,7 +965,7 @@
src.sector = chunk_to_sector(s, pe->e.old_chunk);
src.count = min(s->store->chunk_size, dev_size - src.sector);
- dest.bdev = s->cow->bdev;
+ dest.bdev = s->store->cow->bdev;
dest.sector = chunk_to_sector(s, pe->e.new_chunk);
dest.count = src.count;
@@ -1022,7 +1026,7 @@
static void remap_exception(struct dm_snapshot *s, struct dm_snap_exception *e,
struct bio *bio, chunk_t chunk)
{
- bio->bi_bdev = s->cow->bdev;
+ bio->bi_bdev = s->store->cow->bdev;
bio->bi_sector = chunk_to_sector(s, dm_chunk_number(e->new_chunk) +
(chunk - e->old_chunk)) +
(bio->bi_sector & s->store->chunk_mask);
@@ -1168,7 +1172,7 @@
* make sense.
*/
snprintf(result, maxlen, "%s %s %s %llu",
- snap->origin->name, snap->cow->name,
+ snap->origin->name, snap->store->cow->name,
snap->store->type->name,
(unsigned long long)snap->store->chunk_size);
break;
diff --git a/drivers/md/dm-snap.h b/drivers/md/dm-snap.h
index c2e4ebe..c8a486e 100644
--- a/drivers/md/dm-snap.h
+++ b/drivers/md/dm-snap.h
@@ -27,7 +27,6 @@
struct rw_semaphore lock;
struct dm_dev *origin;
- struct dm_dev *cow;
/* List of snapshots per Origin */
struct list_head list;
