From c7cd55504a5b0fc826a2cd9540845979d24ae542 Mon Sep 17 00:00:00 2001 From: Shenghui Wang Date: Sun, 7 Oct 2018 14:45:41 +0800 Subject: [PATCH 1/3] dm cache: destroy migration_cache if cache target registration failed Commit 7e6358d244e47 ("dm: fix various targets to dm_register_target after module __init resources created") inadvertently introduced this bug when it moved dm_register_target() after the call to KMEM_CACHE(). Fixes: 7e6358d244e47 ("dm: fix various targets to dm_register_target after module __init resources created") Cc: stable@vger.kernel.org Signed-off-by: Shenghui Wang Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-target.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index e13d991e9fb52..b29a8327eed15 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -3484,14 +3484,13 @@ static int __init dm_cache_init(void) int r; migration_cache = KMEM_CACHE(dm_cache_migration, 0); - if (!migration_cache) { - dm_unregister_target(&cache_target); + if (!migration_cache) return -ENOMEM; - } r = dm_register_target(&cache_target); if (r) { DMERR("cache target registration failed: %d", r); + kmem_cache_destroy(migration_cache); return r; } From 9864cd5dc54cade89fd4b0954c2e522841aa247c Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Tue, 9 Oct 2018 14:24:31 +0900 Subject: [PATCH 2/3] dm: fix report zone remapping to account for partition offset If dm-linear or dm-flakey are layered on top of a partition of a zoned block device, remapping of the start sector and write pointer position of the zones reported by a report zones BIO must be modified to account for the target table entry mapping (start offset within the device and entry mapping with the dm device). If the target's backing device is a partition of a whole disk, the start sector on the physical device of the partition must also be accounted for when modifying the zone information. However, dm_remap_zone_report() was not considering this last case, resulting in incorrect zone information remapping with targets using disk partitions. Fix this by calculating the target backing device start sector using the position of the completed report zones BIO and the unchanged position and size of the original report zone BIO. With this value calculated, the start sector and write pointer position of the target zones can be correctly remapped. Fixes: 10999307c14e ("dm: introduce dm_remap_zone_report()") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Signed-off-by: Mike Snitzer --- drivers/md/dm.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 20f7e4ef53422..45abb54037fc6 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1155,12 +1155,14 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors) EXPORT_SYMBOL_GPL(dm_accept_partial_bio); /* - * The zone descriptors obtained with a zone report indicate - * zone positions within the target device. The zone descriptors - * must be remapped to match their position within the dm device. - * A target may call dm_remap_zone_report after completion of a - * REQ_OP_ZONE_REPORT bio to remap the zone descriptors obtained - * from the target device mapping to the dm device. + * The zone descriptors obtained with a zone report indicate zone positions + * within the target backing device, regardless of that device is a partition + * and regardless of the target mapping start sector on the device or partition. + * The zone descriptors start sector and write pointer position must be adjusted + * to match their relative position within the dm device. + * A target may call dm_remap_zone_report() after completion of a + * REQ_OP_ZONE_REPORT bio to remap the zone descriptors obtained from the + * backing device. */ void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start) { @@ -1171,6 +1173,7 @@ void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start) struct blk_zone *zone; unsigned int nr_rep = 0; unsigned int ofst; + sector_t part_offset; struct bio_vec bvec; struct bvec_iter iter; void *addr; @@ -1178,6 +1181,15 @@ void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start) if (bio->bi_status) return; + /* + * bio sector was incremented by the request size on completion. Taking + * into account the original request sector, the target start offset on + * the backing device and the target mapping offset (ti->begin), the + * start sector of the backing device. The partition offset is always 0 + * if the target uses a whole device. + */ + part_offset = bio->bi_iter.bi_sector + ti->begin - (start + bio_end_sector(report_bio)); + /* * Remap the start sector of the reported zones. For sequential zones, * also remap the write pointer position. @@ -1195,6 +1207,7 @@ void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start) /* Set zones start sector */ while (hdr->nr_zones && ofst < bvec.bv_len) { zone = addr + ofst; + zone->start -= part_offset; if (zone->start >= start + ti->len) { hdr->nr_zones = 0; break; @@ -1206,7 +1219,7 @@ void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start) else if (zone->cond == BLK_ZONE_COND_EMPTY) zone->wp = zone->start; else - zone->wp = zone->wp + ti->begin - start; + zone->wp = zone->wp + ti->begin - start - part_offset; } ofst += sizeof(struct blk_zone); hdr->nr_zones--; From beb9caac211c1be1bc118bb62d5cf09c4107e6a5 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Wed, 10 Oct 2018 12:01:55 -0400 Subject: [PATCH 3/3] dm linear: eliminate linear_end_io call if CONFIG_DM_ZONED disabled It is best to avoid any extra overhead associated with bio completion. DM core will indirectly call a DM target's .end_io if it is defined. In the case of DM linear, there is no need to do so (for every bio that completes) if CONFIG_DM_ZONED is not enabled. Avoiding an extra indirect call for every bio completion is very important for ensuring DM linear doesn't incur more overhead that further widens the performance gap between dm-linear and raw block devices. Fixes: 0be12c1c7fce7 ("dm linear: add support for zoned block devices") Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer --- drivers/md/dm-linear.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index d10964d41fd77..172f6fa83c0dd 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -102,6 +102,7 @@ static int linear_map(struct dm_target *ti, struct bio *bio) return DM_MAPIO_REMAPPED; } +#ifdef CONFIG_DM_ZONED static int linear_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *error) { @@ -112,6 +113,7 @@ static int linear_end_io(struct dm_target *ti, struct bio *bio, return DM_ENDIO_DONE; } +#endif static void linear_status(struct dm_target *ti, status_type_t type, unsigned status_flags, char *result, unsigned maxlen) @@ -208,12 +210,16 @@ static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff, static struct target_type linear_target = { .name = "linear", .version = {1, 4, 0}, +#ifdef CONFIG_DM_ZONED + .end_io = linear_end_io, .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_ZONED_HM, +#else + .features = DM_TARGET_PASSES_INTEGRITY, +#endif .module = THIS_MODULE, .ctr = linear_ctr, .dtr = linear_dtr, .map = linear_map, - .end_io = linear_end_io, .status = linear_status, .prepare_ioctl = linear_prepare_ioctl, .iterate_devices = linear_iterate_devices,