From: Jon Brassow <jbrassow@xxxxxxxxxx>
No need for snapshots to keep track of completed exceptions
anymore, since the exception store implementations can do
that (better) now.
Signed-off-by: Jonathan Brassow <jbrassow@xxxxxxxxxx>
Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm-exception-store.h | 8 +---
drivers/md/dm-snap-persistent.c | 29 ++----------
drivers/md/dm-snap-transient.c | 5 +--
drivers/md/dm-snap.c | 95 ++------------------------------------
4 files changed, 13 insertions(+), 124 deletions(-)
diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h
index d3e6a58..f9a54fa 100644
--- a/drivers/md/dm-exception-store.h
+++ b/drivers/md/dm-exception-store.h
@@ -33,13 +33,9 @@ struct dm_exception_store_type {
/*
* The target shouldn't read the COW device until this is
- * called. As exceptions are read from the COW, they are
- * reported back via the callback.
+ * called.
*/
- int (*read_metadata) (struct dm_exception_store *store,
- int (*callback)(void *callback_context,
- chunk_t old, chunk_t new),
- void *callback_context);
+ int (*read_metadata) (struct dm_exception_store *store);
/*
* Find somewhere to store the next exception.
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index fe05bc8..d920f69 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -448,11 +448,7 @@ static int add_exception(struct pstore *ps, chunk_t old, chunk_t new)
* 'full' is filled in to indicate if the area has been
* filled.
*/
-static int insert_exceptions(struct pstore *ps,
- int (*callback)(void *callback_context,
- chunk_t old, chunk_t new),
- void *callback_context,
- int *full)
+static int insert_exceptions(struct pstore *ps, int *full)
{
int r;
unsigned int i;
@@ -488,24 +484,12 @@ static int insert_exceptions(struct pstore *ps,
r = add_exception(ps, de.old_chunk, de.new_chunk);
if (r)
return r;
-
- /*
- * Redundant until a follow-up patch pulls this out
- * (We leave this in for this patch to maintain working
- * version between patches.)
- */
- r = callback(callback_context, de.old_chunk, de.new_chunk);
- if (r)
- return r;
}
return 0;
}
-static int read_exceptions(struct pstore *ps,
- int (*callback)(void *callback_context, chunk_t old,
- chunk_t new),
- void *callback_context)
+static int read_exceptions(struct pstore *ps)
{
int r, full = 1;
@@ -518,7 +502,7 @@ static int read_exceptions(struct pstore *ps,
if (r)
return r;
- r = insert_exceptions(ps, callback, callback_context, &full);
+ r = insert_exceptions(ps, &full);
if (r)
return r;
}
@@ -559,10 +543,7 @@ static void persistent_dtr(struct dm_exception_store *store)
kfree(ps);
}
-static int persistent_read_metadata(struct dm_exception_store *store,
- int (*callback)(void *callback_context,
- chunk_t old, chunk_t new),
- void *callback_context)
+static int persistent_read_metadata(struct dm_exception_store *store)
{
int r, uninitialized_var(new_snapshot);
struct pstore *ps = get_info(store);
@@ -619,7 +600,7 @@ static int persistent_read_metadata(struct dm_exception_store *store,
/*
* Read the metadata.
*/
- r = read_exceptions(ps, callback, callback_context);
+ r = read_exceptions(ps);
return r;
}
diff --git a/drivers/md/dm-snap-transient.c b/drivers/md/dm-snap-transient.c
index eabdcc1..e410f9c 100644
--- a/drivers/md/dm-snap-transient.c
+++ b/drivers/md/dm-snap-transient.c
@@ -44,10 +44,7 @@ static void transient_dtr(struct dm_exception_store *store)
kfree(tc);
}
-static int transient_read_metadata(struct dm_exception_store *store,
- int (*callback)(void *callback_context,
- chunk_t old, chunk_t new),
- void *callback_context)
+static int transient_read_metadata(struct dm_exception_store *store)
{
return 0;
}
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index cb92d8f..7f00271 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -69,7 +69,6 @@ struct dm_snapshot {
atomic_t pending_exceptions_count;
struct dm_exception_table *pending;
- struct dm_exception_table *complete;
/*
* pe_lock protects all pending_exception operations and access
@@ -156,7 +155,6 @@ struct dm_snap_pending_exception {
* Hash table mapping origin volumes to lists of snapshots and
* a lock to protect it
*/
-static struct kmem_cache *exception_cache;
static struct kmem_cache *pending_cache;
struct dm_snap_tracked_chunk {
@@ -336,22 +334,6 @@ static void unregister_snapshot(struct dm_snapshot *s)
up_write(&_origins_lock);
}
-static struct dm_exception *alloc_completed_exception(void *unused)
-{
- struct dm_exception *e;
-
- e = kmem_cache_alloc(exception_cache, GFP_NOIO);
- if (!e)
- e = kmem_cache_alloc(exception_cache, GFP_ATOMIC);
-
- return e;
-}
-
-static void free_completed_exception(struct dm_exception *e, void *unused)
-{
- kmem_cache_free(exception_cache, e);
-}
-
static struct dm_exception *alloc_pending_exception(void *context)
{
struct dm_snapshot *s = context;
@@ -377,29 +359,6 @@ static void free_pending_exception(struct dm_exception *e, void *unused)
atomic_dec(&s->pending_exceptions_count);
}
-/*
- * Callback used by the exception stores to load exceptions when
- * initialising.
- */
-static int dm_add_exception(void *context, chunk_t old, chunk_t new)
-{
- struct dm_snapshot *s = context;
- struct dm_exception *e;
-
- e = dm_alloc_exception(s->complete);
- if (!e)
- return -ENOMEM;
-
- e->old_chunk = old;
-
- /* Consecutive_count is implicitly initialised to zero */
- e->new_chunk = new;
-
- dm_insert_exception(s->complete, e);
-
- return 0;
-}
-
#define min_not_zero(l, r) (((l) == 0) ? (r) : (((r) == 0) ? (l) : min(l, r)))
/*
@@ -450,18 +409,6 @@ static int init_hash_tables(struct dm_snapshot *s)
hash_size = min(hash_size, max_buckets);
hash_size = rounddown_pow_of_two(hash_size);
-
- s->complete = dm_exception_table_create(hash_size,
- DM_CHUNK_CONSECUTIVE_BITS,
- alloc_completed_exception, NULL,
- free_completed_exception, NULL);
- if (!s->complete)
- return -ENOMEM;
-
- /*
- * Allocate hash table for in-flight exceptions
- * Make this smaller than the real hash table
- */
hash_size >>= 3;
if (hash_size < 64)
hash_size = 64;
@@ -469,10 +416,8 @@ static int init_hash_tables(struct dm_snapshot *s)
s->pending = dm_exception_table_create(hash_size, 0,
alloc_pending_exception, s,
free_pending_exception, NULL);
- if (!s->pending) {
- dm_exception_table_destroy(s->complete);
+ if (!s->pending)
return -ENOMEM;
- }
return 0;
}
@@ -620,8 +565,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
spin_lock_init(&s->tracked_chunk_lock);
/* Metadata must only be loaded into one table at once */
- r = s->store->type->read_metadata(s->store, dm_add_exception,
- (void *)s);
+ r = s->store->type->read_metadata(s->store);
if (r < 0) {
ti->error = "Failed to read snapshot metadata";
goto bad_load_and_register;
@@ -663,7 +607,6 @@ bad_pending_pool:
bad_kcopyd:
dm_exception_table_destroy(s->pending);
- dm_exception_table_destroy(s->complete);
bad_hash_tables:
dm_put_device(ti, s->origin);
@@ -683,7 +626,6 @@ static void __free_exceptions(struct dm_snapshot *s)
s->kcopyd_client = NULL;
dm_exception_table_destroy(s->pending);
- dm_exception_table_destroy(s->complete);
}
static void snapshot_dtr(struct dm_target *ti)
@@ -823,7 +765,6 @@ static struct bio *put_pending_exception(struct dm_snap_pending_exception *pe)
static void pending_complete(struct dm_snap_pending_exception *pe, int success)
{
- struct dm_exception *e;
struct dm_snapshot *s = pe->snap;
struct bio *origin_bios = NULL;
struct bio *snapshot_bios = NULL;
@@ -837,18 +778,8 @@ static void pending_complete(struct dm_snap_pending_exception *pe, int success)
goto out;
}
- e = dm_alloc_exception(s->complete);
- if (!e) {
- down_write(&s->lock);
- __invalidate_snapshot(s, -ENOMEM);
- error = 1;
- goto out;
- }
- *e = pe->e;
-
down_write(&s->lock);
if (!s->valid) {
- dm_free_exception(s->complete, e);
error = 1;
goto out;
}
@@ -860,12 +791,6 @@ static void pending_complete(struct dm_snap_pending_exception *pe, int success)
while (__chunk_is_tracked(s, pe->e.old_chunk))
msleep(1);
- /*
- * Add a proper exception, and remove the
- * in-flight exception from the list.
- */
- dm_insert_exception(s->complete, e);
-
out:
dm_remove_exception(&pe->e);
snapshot_bios = bio_list_get(&pe->snapshot_bios);
@@ -1461,25 +1386,18 @@ static int __init dm_snapshot_init(void)
goto bad2;
}
- exception_cache = KMEM_CACHE(dm_exception, 0);
- if (!exception_cache) {
- DMERR("Couldn't create exception cache.");
- r = -ENOMEM;
- goto bad3;
- }
-
pending_cache = KMEM_CACHE(dm_snap_pending_exception, 0);
if (!pending_cache) {
DMERR("Couldn't create pending cache.");
r = -ENOMEM;
- goto bad4;
+ goto bad3;
}
tracked_chunk_cache = KMEM_CACHE(dm_snap_tracked_chunk, 0);
if (!tracked_chunk_cache) {
DMERR("Couldn't create cache to track chunks in use.");
r = -ENOMEM;
- goto bad5;
+ goto bad4;
}
ksnapd = create_singlethread_workqueue("ksnapd");
@@ -1493,10 +1411,8 @@ static int __init dm_snapshot_init(void)
bad_pending_pool:
kmem_cache_destroy(tracked_chunk_cache);
-bad5:
- kmem_cache_destroy(pending_cache);
bad4:
- kmem_cache_destroy(exception_cache);
+ kmem_cache_destroy(pending_cache);
bad3:
exit_origin_hash();
bad2:
@@ -1518,7 +1434,6 @@ static void __exit dm_snapshot_exit(void)
exit_origin_hash();
kmem_cache_destroy(pending_cache);
- kmem_cache_destroy(exception_cache);
kmem_cache_destroy(tracked_chunk_cache);
dm_exception_store_exit();
--
1.6.2.5
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