More changes to allow us to extract the exception table/cache
code from dm-snap.c.
RFC-by: Jonathan Brassow <jbrassow@xxxxxxxxxx>
Index: linux-2.6/drivers/md/dm-snap.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-snap.c
+++ linux-2.6/drivers/md/dm-snap.c
@@ -343,52 +343,76 @@ static void unregister_snapshot(struct d
up_write(&_origins_lock);
}
+struct dm_exception_table_internal {
+ struct dm_exception_table table;
+
+ struct dm_exception *(*alloc_exception)(void *context);
+ void *alloc_context;
+
+ void (*free_exception)(struct dm_exception *e, void *context);
+ void *free_context;
+};
+
/*
* Implementation of the exception hash tables.
* The lowest hash_shift bits of the chunk number are ignored, allowing
* some consecutive chunks to be grouped together.
*/
static struct dm_exception_table *
-dm_exception_table_create(uint32_t size, unsigned hash_shift)
+dm_exception_table_create(uint32_t size, unsigned hash_shift,
+ struct dm_exception *(*alloc_exception)(void *),
+ void *alloc_context,
+ void (*free_exception)(struct dm_exception *e, void *),
+ void *free_context)
{
unsigned int i;
struct dm_exception_table *et;
+ struct dm_exception_table_internal *eti;
- et = kmalloc(sizeof(*et), GFP_KERNEL);
- if (!et)
+ eti = kmalloc(sizeof(*eti), GFP_KERNEL);
+ if (!eti)
return NULL;
+ et = &eti->table;
+
et->hash_shift = hash_shift;
et->hash_mask = size - 1;
et->table = dm_vcalloc(size, sizeof(struct list_head));
if (!et->table) {
- kfree(et);
+ kfree(eti);
return NULL;
}
+ eti->alloc_exception = alloc_exception;
+ eti->alloc_context = alloc_context;
+ eti->free_exception = free_exception;
+ eti->free_context = free_context;
+
for (i = 0; i < size; i++)
INIT_LIST_HEAD(et->table + i);
return et;
}
-static void dm_exception_table_destroy(struct dm_exception_table *et,
- struct kmem_cache *mem)
+static void dm_exception_table_destroy(struct dm_exception_table *et)
{
+ int i, size;
struct list_head *slot;
struct dm_exception *ex, *next;
- int i, size;
+ struct dm_exception_table_internal *eti;
+
+ eti = container_of(et, struct dm_exception_table_internal, table);
size = et->hash_mask + 1;
for (i = 0; i < size; i++) {
slot = et->table + i;
list_for_each_entry_safe (ex, next, slot, hash_list)
- kmem_cache_free(mem, ex);
+ eti->free_exception(ex, eti->free_context);
}
vfree(et->table);
- kfree(et);
+ kfree(eti);
}
static uint32_t exception_hash(struct dm_exception_table *et, chunk_t chunk)
@@ -420,7 +444,25 @@ static struct dm_exception *dm_lookup_ex
return NULL;
}
-static struct dm_exception *alloc_completed_exception(void)
+static struct dm_exception *dm_alloc_exception(struct dm_exception_table *et)
+{
+ struct dm_exception_table_internal *eti;
+
+ eti = container_of(et, struct dm_exception_table_internal, table);
+
+ return eti->alloc_exception(eti->alloc_context);
+}
+
+static void dm_free_exception(struct dm_exception_table *et,
+ struct dm_exception *e)
+{
+ struct dm_exception_table_internal *eti;
+
+ eti = container_of(et, struct dm_exception_table_internal, table);
+ return eti->free_exception(e, eti->free_context);
+}
+
+static struct dm_exception *alloc_completed_exception(void *unused)
{
struct dm_exception *e;
@@ -431,25 +473,30 @@ static struct dm_exception *alloc_comple
return e;
}
-static void free_completed_exception(struct dm_exception *e)
+static void free_completed_exception(struct dm_exception *e, void *unused)
{
kmem_cache_free(exception_cache, e);
}
-static struct dm_snap_pending_exception *alloc_pending_exception(struct dm_snapshot *s)
+static struct dm_exception *alloc_pending_exception(void *context)
{
+ struct dm_snapshot *s = context;
struct dm_snap_pending_exception *pe = mempool_alloc(s->pending_pool,
GFP_NOIO);
atomic_inc(&s->pending_exceptions_count);
pe->snap = s;
- return pe;
+ return &pe->e;
}
-static void free_pending_exception(struct dm_snap_pending_exception *pe)
+static void free_pending_exception(struct dm_exception *e, void *unused)
{
- struct dm_snapshot *s = pe->snap;
+ struct dm_snap_pending_exception *pe;
+ struct dm_snapshot *s;
+
+ pe = container_of(e, struct dm_snap_pending_exception, e);
+ s = pe->snap;
mempool_free(pe, s->pending_pool);
smp_mb__before_atomic_dec();
@@ -476,7 +523,7 @@ static void dm_insert_exception(struct d
new_e->new_chunk == (dm_chunk_number(e->new_chunk) +
dm_consecutive_chunk_count(e) + 1)) {
dm_consecutive_chunk_count_inc(e);
- free_completed_exception(new_e);
+ dm_free_exception(eh, new_e);
return;
}
@@ -486,7 +533,7 @@ static void dm_insert_exception(struct d
dm_consecutive_chunk_count_inc(e);
e->old_chunk--;
e->new_chunk--;
- free_completed_exception(new_e);
+ dm_free_exception(eh, new_e);
return;
}
@@ -507,7 +554,7 @@ static int dm_add_exception(void *contex
struct dm_snapshot *s = context;
struct dm_exception *e;
- e = alloc_completed_exception();
+ e = dm_alloc_exception(s->complete);
if (!e)
return -ENOMEM;
@@ -554,7 +601,9 @@ static int init_hash_tables(struct dm_sn
hash_size = rounddown_pow_of_two(hash_size);
s->complete = dm_exception_table_create(hash_size,
- DM_CHUNK_CONSECUTIVE_BITS);
+ DM_CHUNK_CONSECUTIVE_BITS,
+ alloc_completed_exception, NULL,
+ free_completed_exception, NULL);
if (!s->complete)
return -ENOMEM;
@@ -566,9 +615,11 @@ static int init_hash_tables(struct dm_sn
if (hash_size < 64)
hash_size = 64;
- s->pending = dm_exception_table_create(hash_size, 0);
+ 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, exception_cache);
+ dm_exception_table_destroy(s->complete);
return -ENOMEM;
}
@@ -760,8 +811,8 @@ bad_pending_pool:
dm_kcopyd_client_destroy(s->kcopyd_client);
bad_kcopyd:
- dm_exception_table_destroy(s->pending, pending_cache);
- dm_exception_table_destroy(s->complete, exception_cache);
+ dm_exception_table_destroy(s->pending);
+ dm_exception_table_destroy(s->complete);
bad_hash_tables:
dm_put_device(ti, s->origin);
@@ -780,8 +831,8 @@ static void __free_exceptions(struct dm_
dm_kcopyd_client_destroy(s->kcopyd_client);
s->kcopyd_client = NULL;
- dm_exception_table_destroy(s->pending, pending_cache);
- dm_exception_table_destroy(s->complete, exception_cache);
+ dm_exception_table_destroy(s->pending);
+ dm_exception_table_destroy(s->complete);
}
static void snapshot_dtr(struct dm_target *ti)
@@ -905,7 +956,7 @@ static struct bio *put_pending_exception
if (primary_pe &&
atomic_dec_and_test(&primary_pe->ref_count)) {
origin_bios = bio_list_get(&primary_pe->origin_bios);
- free_pending_exception(primary_pe);
+ dm_free_exception(pe->snap->pending, &pe->e);
}
/*
@@ -913,7 +964,7 @@ static struct bio *put_pending_exception
* it's not itself a primary pe.
*/
if (!primary_pe || primary_pe != pe)
- free_pending_exception(pe);
+ dm_free_exception(pe->snap->pending, &pe->e);
return origin_bios;
}
@@ -934,7 +985,7 @@ static void pending_complete(struct dm_s
goto out;
}
- e = alloc_completed_exception();
+ e = dm_alloc_exception(s->complete);
if (!e) {
down_write(&s->lock);
__invalidate_snapshot(s, -ENOMEM);
@@ -945,7 +996,7 @@ static void pending_complete(struct dm_s
down_write(&s->lock);
if (!s->valid) {
- free_completed_exception(e);
+ dm_free_exception(s->complete, e);
error = 1;
goto out;
}
@@ -1040,7 +1091,7 @@ static void start_copy(struct dm_snap_pe
static struct dm_snap_pending_exception *
__find_pending_exception(struct dm_snapshot *s, struct bio *bio)
{
- struct dm_exception *e;
+ struct dm_exception *e, *tmp_e;
struct dm_snap_pending_exception *pe;
chunk_t chunk = sector_to_chunk(s->store, bio->bi_sector);
@@ -1059,17 +1110,18 @@ __find_pending_exception(struct dm_snaps
* to hold the lock while we do this.
*/
up_write(&s->lock);
- pe = alloc_pending_exception(s);
+ tmp_e = dm_alloc_exception(s->pending);
+ pe = container_of(tmp_e, struct dm_snap_pending_exception, e);
down_write(&s->lock);
if (!s->valid) {
- free_pending_exception(pe);
+ dm_free_exception(s->pending, &pe->e);
return NULL;
}
e = dm_lookup_exception(s->pending, chunk);
if (e) {
- free_pending_exception(pe);
+ dm_free_exception(s->pending, &pe->e);
pe = container_of(e, struct dm_snap_pending_exception, e);
goto out;
}
@@ -1082,7 +1134,7 @@ __find_pending_exception(struct dm_snaps
pe->started = 0;
if (s->store->type->prepare_exception(s->store, &pe->e)) {
- free_pending_exception(pe);
+ dm_free_exception(s->pending, &pe->e);
return NULL;
}
@@ -1324,7 +1376,7 @@ static int __origin_write(struct list_he
if (first && atomic_dec_and_test(&primary_pe->ref_count)) {
flush_bios(bio_list_get(&primary_pe->origin_bios));
- free_pending_exception(primary_pe);
+ dm_free_exception(snap->pending, &primary_pe->e);
/* If we got here, pe_queue is necessarily empty. */
return r;
}
--
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