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path: root/drivers/md/dm-snap.c
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Diffstat (limited to 'drivers/md/dm-snap.c')
-rw-r--r--drivers/md/dm-snap.c84
1 files changed, 63 insertions, 21 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 9ecff5f3023a..6f758870fc19 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -30,16 +30,6 @@ static const char dm_snapshot_merge_target_name[] = "snapshot-merge";
((ti)->type->name == dm_snapshot_merge_target_name)
/*
- * The percentage increment we will wake up users at
- */
-#define WAKE_UP_PERCENT 5
-
-/*
- * kcopyd priority of snapshot operations
- */
-#define SNAPSHOT_COPY_PRIORITY 2
-
-/*
* The size of the mempool used to track chunks in use.
*/
#define MIN_IOS 256
@@ -180,6 +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;
};
/*
@@ -1055,8 +1052,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
s = kmalloc(sizeof(*s), GFP_KERNEL);
if (!s) {
- ti->error = "Cannot allocate snapshot context private "
- "structure";
+ ti->error = "Cannot allocate private snapshot structure";
r = -ENOMEM;
goto bad;
}
@@ -1380,6 +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) {
@@ -1415,10 +1412,15 @@ static void pending_complete(struct dm_snap_pending_exception *pe, int success)
*/
dm_insert_exception(&s->complete, e);
- out:
+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();
@@ -1426,10 +1428,15 @@ static void pending_complete(struct dm_snap_pending_exception *pe, int success)
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);
}
@@ -1480,8 +1487,33 @@ static void start_copy(struct dm_snap_pending_exception *pe)
dest.count = src.count;
/* Hand over to kcopyd */
- dm_kcopyd_copy(s->kcopyd_client,
- &src, 1, &dest, 0, copy_callback, 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 *
@@ -1519,6 +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);
@@ -1612,10 +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;
@@ -1628,9 +1670,9 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
map_context->ptr = track_chunk(s, chunk);
}
- out_unlock:
+out_unlock:
up_write(&s->lock);
- out:
+out:
return r;
}
@@ -1974,7 +2016,7 @@ static int __origin_write(struct list_head *snapshots, sector_t sector,
pe_to_start_now = pe;
}
- next_snapshot:
+next_snapshot:
up_write(&snap->lock);
if (pe_to_start_now) {