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-rw-r--r--drivers/md/dm-exception-store.c30
-rw-r--r--drivers/md/dm-exception-store.h12
-rw-r--r--drivers/md/dm-snap-persistent.c12
-rw-r--r--drivers/md/dm-snap-transient.c7
-rw-r--r--drivers/md/dm-snap.c74
5 files changed, 78 insertions, 57 deletions
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 205215968ff..2b7907b6dd0 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -172,7 +172,8 @@ int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
}
/* Validate the chunk size against the device block size */
- if (chunk_size % (bdev_logical_block_size(store->cow->bdev) >> 9)) {
+ if (chunk_size %
+ (bdev_logical_block_size(dm_snap_cow(store->snap)->bdev) >> 9)) {
*error = "Chunk size is not a multiple of device blocksize";
return -EINVAL;
}
@@ -190,6 +191,7 @@ int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
}
int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
+ struct dm_snapshot *snap,
unsigned *args_used,
struct dm_exception_store **store)
{
@@ -198,7 +200,7 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
struct dm_exception_store *tmp_store;
char persistent;
- if (argc < 3) {
+ if (argc < 2) {
ti->error = "Insufficient exception store arguments";
return -EINVAL;
}
@@ -209,7 +211,7 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
return -ENOMEM;
}
- persistent = toupper(*argv[1]);
+ persistent = toupper(*argv[0]);
if (persistent == 'P')
type = get_type("P");
else if (persistent == 'N')
@@ -227,32 +229,23 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
}
tmp_store->type = type;
- tmp_store->ti = ti;
+ tmp_store->snap = snap;
- 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);
+ r = set_chunk_size(tmp_store, argv[1], &ti->error);
if (r)
- goto bad_ctr;
+ goto bad;
r = type->ctr(tmp_store, 0, NULL);
if (r) {
ti->error = "Exception store type constructor failed";
- goto bad_ctr;
+ goto bad;
}
- *args_used = 3;
+ *args_used = 2;
*store = tmp_store;
return 0;
-bad_ctr:
- dm_put_device(ti, tmp_store->cow);
-bad_cow:
+bad:
put_type(type);
bad_type:
kfree(tmp_store);
@@ -263,7 +256,6 @@ 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);
}
diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h
index 366c8b1fca3..bb8874653de 100644
--- a/drivers/md/dm-exception-store.h
+++ b/drivers/md/dm-exception-store.h
@@ -94,11 +94,11 @@ struct dm_exception_store_type {
struct list_head list;
};
+struct dm_snapshot;
+
struct dm_exception_store {
struct dm_exception_store_type *type;
- struct dm_target *ti;
-
- struct dm_dev *cow;
+ struct dm_snapshot *snap;
/* Size of data blocks saved - must be a power of 2 */
unsigned chunk_size;
@@ -109,6 +109,11 @@ struct dm_exception_store {
};
/*
+ * Obtain the cow device used by a given snapshot.
+ */
+struct dm_dev *dm_snap_cow(struct dm_snapshot *snap);
+
+/*
* Funtions to manipulate consecutive chunks
*/
# if defined(CONFIG_LBDAF) || (BITS_PER_LONG == 64)
@@ -173,6 +178,7 @@ int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
char **error);
int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
+ struct dm_snapshot *snap,
unsigned *args_used,
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 767065f6c5f..157999ebd23 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -214,7 +214,7 @@ static int chunk_io(struct pstore *ps, void *area, chunk_t chunk, int rw,
int metadata)
{
struct dm_io_region where = {
- .bdev = ps->store->cow->bdev,
+ .bdev = dm_snap_cow(ps->store->snap)->bdev,
.sector = ps->store->chunk_size * chunk,
.count = ps->store->chunk_size,
};
@@ -294,7 +294,8 @@ static int read_header(struct pstore *ps, int *new_snapshot)
*/
if (!ps->store->chunk_size) {
ps->store->chunk_size = max(DM_CHUNK_SIZE_DEFAULT_SECTORS,
- bdev_logical_block_size(ps->store->cow->bdev) >> 9);
+ bdev_logical_block_size(dm_snap_cow(ps->store->snap)->
+ bdev) >> 9);
ps->store->chunk_mask = ps->store->chunk_size - 1;
ps->store->chunk_shift = ffs(ps->store->chunk_size) - 1;
chunk_size_supplied = 0;
@@ -497,7 +498,7 @@ static void persistent_usage(struct dm_exception_store *store,
struct pstore *ps = get_info(store);
*sectors_allocated = ps->next_free * store->chunk_size;
- *total_sectors = get_dev_size(store->cow->bdev);
+ *total_sectors = get_dev_size(dm_snap_cow(store->snap)->bdev);
/*
* First chunk is the fixed header.
@@ -596,7 +597,7 @@ static int persistent_prepare_exception(struct dm_exception_store *store,
struct pstore *ps = get_info(store);
uint32_t stride;
chunk_t next_free;
- sector_t size = get_dev_size(store->cow->bdev);
+ sector_t size = get_dev_size(dm_snap_cow(store->snap)->bdev);
/* Is there enough room ? */
if (size < ((ps->next_free + 1) * store->chunk_size))
@@ -733,8 +734,7 @@ static unsigned persistent_status(struct dm_exception_store *store,
case STATUSTYPE_INFO:
break;
case STATUSTYPE_TABLE:
- DMEMIT(" %s P %llu", store->cow->name,
- (unsigned long long)store->chunk_size);
+ DMEMIT(" P %llu", (unsigned long long)store->chunk_size);
}
return sz;
diff --git a/drivers/md/dm-snap-transient.c b/drivers/md/dm-snap-transient.c
index 245a50c7337..a0898a66a2f 100644
--- a/drivers/md/dm-snap-transient.c
+++ b/drivers/md/dm-snap-transient.c
@@ -39,7 +39,7 @@ static int transient_prepare_exception(struct dm_exception_store *store,
struct dm_exception *e)
{
struct transient_c *tc = store->context;
- sector_t size = get_dev_size(store->cow->bdev);
+ sector_t size = get_dev_size(dm_snap_cow(store->snap)->bdev);
if (size < (tc->next_free + store->chunk_size))
return -1;
@@ -65,7 +65,7 @@ static void transient_usage(struct dm_exception_store *store,
sector_t *metadata_sectors)
{
*sectors_allocated = ((struct transient_c *) store->context)->next_free;
- *total_sectors = get_dev_size(store->cow->bdev);
+ *total_sectors = get_dev_size(dm_snap_cow(store->snap)->bdev);
*metadata_sectors = 0;
}
@@ -94,8 +94,7 @@ static unsigned transient_status(struct dm_exception_store *store,
case STATUSTYPE_INFO:
break;
case STATUSTYPE_TABLE:
- DMEMIT(" %s N %llu", store->cow->name,
- (unsigned long long)store->chunk_size);
+ DMEMIT(" N %llu", (unsigned long long)store->chunk_size);
}
return sz;
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 8bd77cbd7e4..dc500a6f623 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -59,6 +59,9 @@ struct dm_snapshot {
struct rw_semaphore lock;
struct dm_dev *origin;
+ struct dm_dev *cow;
+
+ struct dm_target *ti;
/* List of snapshots per Origin */
struct list_head list;
@@ -97,6 +100,12 @@ struct dm_snapshot {
struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
};
+struct dm_dev *dm_snap_cow(struct dm_snapshot *s)
+{
+ return s->cow;
+}
+EXPORT_SYMBOL(dm_snap_cow);
+
static struct workqueue_struct *ksnapd;
static void flush_queued_bios(struct work_struct *work);
@@ -558,7 +567,7 @@ static int init_hash_tables(struct dm_snapshot *s)
* Calculate based on the size of the original volume or
* the COW volume...
*/
- cow_dev_size = get_dev_size(s->store->cow->bdev);
+ cow_dev_size = get_dev_size(s->cow->bdev);
origin_dev_size = get_dev_size(s->origin->bdev);
max_buckets = calc_max_buckets();
@@ -596,45 +605,55 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
struct dm_snapshot *s;
int i;
int r = -EINVAL;
- char *origin_path;
- struct dm_exception_store *store;
+ char *origin_path, *cow_path;
unsigned args_used;
if (argc != 4) {
ti->error = "requires exactly 4 arguments";
r = -EINVAL;
- goto bad_args;
+ goto bad;
}
origin_path = argv[0];
argv++;
argc--;
- r = dm_exception_store_create(ti, argc, argv, &args_used, &store);
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s) {
+ ti->error = "Cannot allocate snapshot context private "
+ "structure";
+ r = -ENOMEM;
+ goto bad;
+ }
+
+ cow_path = argv[0];
+ argv++;
+ argc--;
+
+ r = dm_get_device(ti, cow_path, 0, 0,
+ FMODE_READ | FMODE_WRITE, &s->cow);
+ if (r) {
+ ti->error = "Cannot get COW device";
+ goto bad_cow;
+ }
+
+ r = dm_exception_store_create(ti, argc, argv, s, &args_used, &s->store);
if (r) {
ti->error = "Couldn't create exception store";
r = -EINVAL;
- goto bad_args;
+ goto bad_store;
}
argv += args_used;
argc -= args_used;
- s = kmalloc(sizeof(*s), GFP_KERNEL);
- if (!s) {
- ti->error = "Cannot allocate snapshot context private "
- "structure";
- r = -ENOMEM;
- goto bad_snap;
- }
-
r = dm_get_device(ti, origin_path, 0, ti->len, FMODE_READ, &s->origin);
if (r) {
ti->error = "Cannot get origin device";
goto bad_origin;
}
- s->store = store;
+ s->ti = ti;
s->valid = 1;
s->active = 0;
atomic_set(&s->pending_exceptions_count, 0);
@@ -723,12 +742,15 @@ bad_hash_tables:
dm_put_device(ti, s->origin);
bad_origin:
- kfree(s);
+ dm_exception_store_destroy(s->store);
-bad_snap:
- dm_exception_store_destroy(store);
+bad_store:
+ dm_put_device(ti, s->cow);
-bad_args:
+bad_cow:
+ kfree(s);
+
+bad:
return r;
}
@@ -777,6 +799,8 @@ static void snapshot_dtr(struct dm_target *ti)
dm_exception_store_destroy(s->store);
+ dm_put_device(ti, s->cow);
+
kfree(s);
}
@@ -839,7 +863,7 @@ static void __invalidate_snapshot(struct dm_snapshot *s, int err)
s->valid = 0;
- dm_table_event(s->store->ti->table);
+ dm_table_event(s->ti->table);
}
static void get_pending_exception(struct dm_snap_pending_exception *pe)
@@ -977,7 +1001,7 @@ static void start_copy(struct dm_snap_pending_exception *pe)
src.sector = chunk_to_sector(s->store, pe->e.old_chunk);
src.count = min((sector_t)s->store->chunk_size, dev_size - src.sector);
- dest.bdev = s->store->cow->bdev;
+ dest.bdev = s->cow->bdev;
dest.sector = chunk_to_sector(s->store, pe->e.new_chunk);
dest.count = src.count;
@@ -1038,7 +1062,7 @@ __find_pending_exception(struct dm_snapshot *s,
static void remap_exception(struct dm_snapshot *s, struct dm_exception *e,
struct bio *bio, chunk_t chunk)
{
- bio->bi_bdev = s->store->cow->bdev;
+ bio->bi_bdev = s->cow->bdev;
bio->bi_sector = chunk_to_sector(s->store,
dm_chunk_number(e->new_chunk) +
(chunk - e->old_chunk)) +
@@ -1056,7 +1080,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
struct dm_snap_pending_exception *pe = NULL;
if (unlikely(bio_empty_barrier(bio))) {
- bio->bi_bdev = s->store->cow->bdev;
+ bio->bi_bdev = s->cow->bdev;
return DM_MAPIO_REMAPPED;
}
@@ -1200,7 +1224,7 @@ static int snapshot_status(struct dm_target *ti, status_type_t type,
* to make private copies if the output is to
* make sense.
*/
- DMEMIT("%s", snap->origin->name);
+ DMEMIT("%s %s", snap->origin->name, snap->cow->name);
snap->store->type->status(snap->store, type, result + sz,
maxlen - sz);
break;
@@ -1240,7 +1264,7 @@ static int __origin_write(struct list_head *snapshots, struct bio *bio)
goto next_snapshot;
/* Nothing to do if writing beyond end of snapshot */
- if (bio->bi_sector >= dm_table_get_size(snap->store->ti->table))
+ if (bio->bi_sector >= dm_table_get_size(snap->ti->table))
goto next_snapshot;
/*
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-04 14:44:56 +0000