#include <linux/blkdev.h>
#include <linux/ctype.h>
#include <linux/device-mapper.h>
+#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kdev_t.h>
#include <linux/log2.h>
#include <linux/dm-kcopyd.h>
+#include "dm-exception-store.h"
#include "dm-snap.h"
#include "dm-bio-list.h"
list_add(&new_e->hash_list, e ? &e->hash_list : l);
}
-int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new)
+/*
+ * 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_snap_exception *e;
e = alloc_exception();
spin_lock_init(&s->tracked_chunk_lock);
/* Metadata must only be loaded into one table at once */
- r = s->store.read_metadata(&s->store);
+ r = s->store.read_metadata(&s->store, dm_add_exception, (void *)s);
if (r < 0) {
ti->error = "Failed to read snapshot metadata";
goto bad_load_and_register;
unregister_snapshot(s);
while (atomic_read(&s->pending_exceptions_count))
- yield();
+ msleep(1);
/*
* Ensure instructions in mempool_destroy aren't reordered
* before atomic_read.
/*
* Check for conflicting reads. This is extremely improbable,
- * so yield() is sufficient and there is no need for a wait queue.
+ * so msleep(1) is sufficient and there is no need for a wait queue.
*/
while (__chunk_is_tracked(s, pe->e.old_chunk))
- yield();
+ msleep(1);
/*
* Add a proper exception, and remove the
&src, 1, &dest, 0, copy_callback, pe);
}
+static struct dm_snap_pending_exception *
+__lookup_pending_exception(struct dm_snapshot *s, chunk_t chunk)
+{
+ struct dm_snap_exception *e = lookup_exception(&s->pending, chunk);
+
+ if (!e)
+ return NULL;
+
+ return container_of(e, struct dm_snap_pending_exception, e);
+}
+
/*
* Looks to see if this snapshot already has a pending exception
* for this chunk, otherwise it allocates a new one and inserts
* this.
*/
static struct dm_snap_pending_exception *
-__find_pending_exception(struct dm_snapshot *s, struct bio *bio)
+__find_pending_exception(struct dm_snapshot *s,
+ struct dm_snap_pending_exception *pe, chunk_t chunk)
{
- struct dm_snap_exception *e;
- struct dm_snap_pending_exception *pe;
- chunk_t chunk = sector_to_chunk(s, bio->bi_sector);
-
- /*
- * Is there a pending exception for this already ?
- */
- e = lookup_exception(&s->pending, chunk);
- if (e) {
- /* cast the exception to a pending exception */
- pe = container_of(e, struct dm_snap_pending_exception, e);
- goto out;
- }
-
- /*
- * Create a new pending exception, we don't want
- * to hold the lock while we do this.
- */
- up_write(&s->lock);
- pe = alloc_pending_exception(s);
- down_write(&s->lock);
+ struct dm_snap_pending_exception *pe2;
- if (!s->valid) {
- free_pending_exception(pe);
- return NULL;
- }
-
- e = lookup_exception(&s->pending, chunk);
- if (e) {
+ pe2 = __lookup_pending_exception(s, chunk);
+ if (pe2) {
free_pending_exception(pe);
- pe = container_of(e, struct dm_snap_pending_exception, e);
- goto out;
+ return pe2;
}
pe->e.old_chunk = chunk;
get_pending_exception(pe);
insert_exception(&s->pending, &pe->e);
- out:
return pe;
}
* writeable.
*/
if (bio_rw(bio) == WRITE) {
- pe = __find_pending_exception(s, bio);
+ pe = __lookup_pending_exception(s, chunk);
if (!pe) {
- __invalidate_snapshot(s, -ENOMEM);
- r = -EIO;
- goto out_unlock;
+ up_write(&s->lock);
+ pe = alloc_pending_exception(s);
+ down_write(&s->lock);
+
+ if (!s->valid) {
+ free_pending_exception(pe);
+ r = -EIO;
+ goto out_unlock;
+ }
+
+ e = lookup_exception(&s->complete, chunk);
+ if (e) {
+ free_pending_exception(pe);
+ remap_exception(s, e, bio, chunk);
+ goto out_unlock;
+ }
+
+ pe = __find_pending_exception(s, pe, chunk);
+ if (!pe) {
+ __invalidate_snapshot(s, -ENOMEM);
+ r = -EIO;
+ goto out_unlock;
+ }
}
remap_exception(s, &pe->e, bio, chunk);
if (e)
goto next_snapshot;
- pe = __find_pending_exception(snap, bio);
+ pe = __lookup_pending_exception(snap, chunk);
if (!pe) {
- __invalidate_snapshot(snap, -ENOMEM);
- goto next_snapshot;
+ up_write(&snap->lock);
+ pe = alloc_pending_exception(snap);
+ down_write(&snap->lock);
+
+ if (!snap->valid) {
+ free_pending_exception(pe);
+ goto next_snapshot;
+ }
+
+ e = lookup_exception(&snap->complete, chunk);
+ if (e) {
+ free_pending_exception(pe);
+ goto next_snapshot;
+ }
+
+ pe = __find_pending_exception(snap, pe, chunk);
+ if (!pe) {
+ __invalidate_snapshot(snap, -ENOMEM);
+ goto next_snapshot;
+ }
}
if (!primary_pe) {
{
int r;
+ r = dm_exception_store_init();
+ if (r) {
+ DMERR("Failed to initialize exception stores");
+ return r;
+ }
+
r = dm_register_target(&snapshot_target);
if (r) {
DMERR("snapshot target register failed %d", r);
return 0;
- bad_pending_pool:
+bad_pending_pool:
kmem_cache_destroy(tracked_chunk_cache);
- bad5:
+bad5:
kmem_cache_destroy(pending_cache);
- bad4:
+bad4:
kmem_cache_destroy(exception_cache);
- bad3:
+bad3:
exit_origin_hash();
- bad2:
+bad2:
dm_unregister_target(&origin_target);
- bad1:
+bad1:
dm_unregister_target(&snapshot_target);
return r;
}
static void __exit dm_snapshot_exit(void)
{
- int r;
-
destroy_workqueue(ksnapd);
- r = dm_unregister_target(&snapshot_target);
- if (r)
- DMERR("snapshot unregister failed %d", r);
-
- r = dm_unregister_target(&origin_target);
- if (r)
- DMERR("origin unregister failed %d", r);
+ dm_unregister_target(&snapshot_target);
+ dm_unregister_target(&origin_target);
exit_origin_hash();
kmem_cache_destroy(pending_cache);
kmem_cache_destroy(exception_cache);
kmem_cache_destroy(tracked_chunk_cache);
+
+ dm_exception_store_exit();
}
/* Module hooks */
projects / mv-sheeva.git / blobdiff