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-rw-r--r--drivers/md/dm-kcopyd.c31
-rw-r--r--drivers/md/dm-snap.c60
-rw-r--r--include/linux/dm-kcopyd.h15
3 files changed, 103 insertions, 3 deletions
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index 98725e11932..f8214702963 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -617,6 +617,37 @@ int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
}
EXPORT_SYMBOL(dm_kcopyd_copy);
+void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc,
+ dm_kcopyd_notify_fn fn, void *context)
+{
+ struct kcopyd_job *job;
+
+ job = mempool_alloc(kc->job_pool, GFP_NOIO);
+
+ memset(job, 0, sizeof(struct kcopyd_job));
+ job->kc = kc;
+ job->fn = fn;
+ job->context = context;
+
+ atomic_inc(&kc->nr_jobs);
+
+ return job;
+}
+EXPORT_SYMBOL(dm_kcopyd_prepare_callback);
+
+void dm_kcopyd_do_callback(void *j, int read_err, unsigned long write_err)
+{
+ struct kcopyd_job *job = j;
+ struct dm_kcopyd_client *kc = job->kc;
+
+ job->read_err = read_err;
+ job->write_err = write_err;
+
+ push(&kc->complete_jobs, job);
+ wake(kc);
+}
+EXPORT_SYMBOL(dm_kcopyd_do_callback);
+
/*
* Cancels a kcopyd job, eg. someone might be deactivating a
* mirror.
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 94dee05dd28..6f758870fc1 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -170,6 +170,13 @@ struct dm_snap_pending_exception {
* kcopyd.
*/
int started;
+
+ /*
+ * For writing a complete chunk, bypassing the copy.
+ */
+ struct bio *full_bio;
+ bio_end_io_t *full_bio_end_io;
+ void *full_bio_private;
};
/*
@@ -1369,6 +1376,7 @@ static void pending_complete(struct dm_snap_pending_exception *pe, int success)
struct dm_snapshot *s = pe->snap;
struct bio *origin_bios = NULL;
struct bio *snapshot_bios = NULL;
+ struct bio *full_bio = NULL;
int error = 0;
if (!success) {
@@ -1408,6 +1416,11 @@ out:
dm_remove_exception(&pe->e);
snapshot_bios = bio_list_get(&pe->snapshot_bios);
origin_bios = bio_list_get(&pe->origin_bios);
+ full_bio = pe->full_bio;
+ if (full_bio) {
+ full_bio->bi_end_io = pe->full_bio_end_io;
+ full_bio->bi_private = pe->full_bio_private;
+ }
free_pending_exception(pe);
increment_pending_exceptions_done_count();
@@ -1415,10 +1428,15 @@ out:
up_write(&s->lock);
/* Submit any pending write bios */
- if (error)
+ if (error) {
+ if (full_bio)
+ bio_io_error(full_bio);
error_bios(snapshot_bios);
- else
+ } else {
+ if (full_bio)
+ bio_endio(full_bio, 0);
flush_bios(snapshot_bios);
+ }
retry_origin_bios(s, origin_bios);
}
@@ -1472,6 +1490,32 @@ static void start_copy(struct dm_snap_pending_exception *pe)
dm_kcopyd_copy(s->kcopyd_client, &src, 1, &dest, 0, copy_callback, pe);
}
+static void full_bio_end_io(struct bio *bio, int error)
+{
+ void *callback_data = bio->bi_private;
+
+ dm_kcopyd_do_callback(callback_data, 0, error ? 1 : 0);
+}
+
+static void start_full_bio(struct dm_snap_pending_exception *pe,
+ struct bio *bio)
+{
+ struct dm_snapshot *s = pe->snap;
+ void *callback_data;
+
+ pe->full_bio = bio;
+ pe->full_bio_end_io = bio->bi_end_io;
+ pe->full_bio_private = bio->bi_private;
+
+ callback_data = dm_kcopyd_prepare_callback(s->kcopyd_client,
+ copy_callback, pe);
+
+ bio->bi_end_io = full_bio_end_io;
+ bio->bi_private = callback_data;
+
+ generic_make_request(bio);
+}
+
static struct dm_snap_pending_exception *
__lookup_pending_exception(struct dm_snapshot *s, chunk_t chunk)
{
@@ -1507,6 +1551,7 @@ __find_pending_exception(struct dm_snapshot *s,
bio_list_init(&pe->origin_bios);
bio_list_init(&pe->snapshot_bios);
pe->started = 0;
+ pe->full_bio = NULL;
if (s->store->type->prepare_exception(s->store, &pe->e)) {
free_pending_exception(pe);
@@ -1600,10 +1645,19 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
}
remap_exception(s, &pe->e, bio, chunk);
- bio_list_add(&pe->snapshot_bios, bio);
r = DM_MAPIO_SUBMITTED;
+ if (!pe->started &&
+ bio->bi_size == (s->store->chunk_size << SECTOR_SHIFT)) {
+ pe->started = 1;
+ up_write(&s->lock);
+ start_full_bio(pe, bio);
+ goto out;
+ }
+
+ bio_list_add(&pe->snapshot_bios, bio);
+
if (!pe->started) {
/* this is protected by snap->lock */
pe->started = 1;
diff --git a/include/linux/dm-kcopyd.h b/include/linux/dm-kcopyd.h
index 298d587e349..5e54458e920 100644
--- a/include/linux/dm-kcopyd.h
+++ b/include/linux/dm-kcopyd.h
@@ -42,5 +42,20 @@ int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
unsigned num_dests, struct dm_io_region *dests,
unsigned flags, dm_kcopyd_notify_fn fn, void *context);
+/*
+ * Prepare a callback and submit it via the kcopyd thread.
+ *
+ * dm_kcopyd_prepare_callback allocates a callback structure and returns it.
+ * It must not be called from interrupt context.
+ * The returned value should be passed into dm_kcopyd_do_callback.
+ *
+ * dm_kcopyd_do_callback submits the callback.
+ * It may be called from interrupt context.
+ * The callback is issued from the kcopyd thread.
+ */
+void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc,
+ dm_kcopyd_notify_fn fn, void *context);
+void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err);
+
#endif /* __KERNEL__ */
#endif /* _LINUX_DM_KCOPYD_H */