diff options
Diffstat (limited to 'drivers/md/dm-snap.c')
| -rw-r--r-- | drivers/md/dm-snap.c | 67 |
1 files changed, 48 insertions, 19 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 8e0caed0bf74..5bd2290cfb1e 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -2141,6 +2141,11 @@ static int origin_write_extent(struct dm_snapshot *merging_snap, * Origin: maps a linear range of a device, with hooks for snapshotting. */ +struct dm_origin { + struct dm_dev *dev; + unsigned split_boundary; +}; + /* * Construct an origin mapping: <dev_path> * The context for an origin is merely a 'struct dm_dev *' @@ -2149,41 +2154,65 @@ static int origin_write_extent(struct dm_snapshot *merging_snap, static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv) { int r; - struct dm_dev *dev; + struct dm_origin *o; if (argc != 1) { ti->error = "origin: incorrect number of arguments"; return -EINVAL; } - r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev); + o = kmalloc(sizeof(struct dm_origin), GFP_KERNEL); + if (!o) { + ti->error = "Cannot allocate private origin structure"; + r = -ENOMEM; + goto bad_alloc; + } + + r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &o->dev); if (r) { ti->error = "Cannot get target device"; - return r; + goto bad_open; } - ti->private = dev; + ti->private = o; ti->num_flush_bios = 1; return 0; + +bad_open: + kfree(o); +bad_alloc: + return r; } static void origin_dtr(struct dm_target *ti) { - struct dm_dev *dev = ti->private; - dm_put_device(ti, dev); + struct dm_origin *o = ti->private; + dm_put_device(ti, o->dev); + kfree(o); } static int origin_map(struct dm_target *ti, struct bio *bio) { - struct dm_dev *dev = ti->private; - bio->bi_bdev = dev->bdev; + struct dm_origin *o = ti->private; + unsigned available_sectors; - if (bio->bi_rw & REQ_FLUSH) + bio->bi_bdev = o->dev->bdev; + + if (unlikely(bio->bi_rw & REQ_FLUSH)) return DM_MAPIO_REMAPPED; + if (bio_rw(bio) != WRITE) + return DM_MAPIO_REMAPPED; + + available_sectors = o->split_boundary - + ((unsigned)bio->bi_iter.bi_sector & (o->split_boundary - 1)); + + if (bio_sectors(bio) > available_sectors) + dm_accept_partial_bio(bio, available_sectors); + /* Only tell snapshots if this is a write */ - return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : DM_MAPIO_REMAPPED; + return do_origin(o->dev, bio); } /* @@ -2192,15 +2221,15 @@ static int origin_map(struct dm_target *ti, struct bio *bio) */ static void origin_resume(struct dm_target *ti) { - struct dm_dev *dev = ti->private; + struct dm_origin *o = ti->private; - ti->max_io_len = get_origin_minimum_chunksize(dev->bdev); + o->split_boundary = get_origin_minimum_chunksize(o->dev->bdev); } static void origin_status(struct dm_target *ti, status_type_t type, unsigned status_flags, char *result, unsigned maxlen) { - struct dm_dev *dev = ti->private; + struct dm_origin *o = ti->private; switch (type) { case STATUSTYPE_INFO: @@ -2208,7 +2237,7 @@ static void origin_status(struct dm_target *ti, status_type_t type, break; case STATUSTYPE_TABLE: - snprintf(result, maxlen, "%s", dev->name); + snprintf(result, maxlen, "%s", o->dev->name); break; } } @@ -2216,13 +2245,13 @@ static void origin_status(struct dm_target *ti, status_type_t type, static int origin_merge(struct dm_target *ti, struct bvec_merge_data *bvm, struct bio_vec *biovec, int max_size) { - struct dm_dev *dev = ti->private; - struct request_queue *q = bdev_get_queue(dev->bdev); + struct dm_origin *o = ti->private; + struct request_queue *q = bdev_get_queue(o->dev->bdev); if (!q->merge_bvec_fn) return max_size; - bvm->bi_bdev = dev->bdev; + bvm->bi_bdev = o->dev->bdev; return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); } @@ -2230,9 +2259,9 @@ static int origin_merge(struct dm_target *ti, struct bvec_merge_data *bvm, static int origin_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data) { - struct dm_dev *dev = ti->private; + struct dm_origin *o = ti->private; - return fn(ti, dev, 0, ti->len, data); + return fn(ti, o->dev, 0, ti->len, data); } static struct target_type origin_target = { |