dm: handle failures in dm_table_set_restrictions

If dm_table_set_restrictions() fails while swapping tables,
device-mapper will continue using the previous table. It must be sure to
leave the mapped_device in it's previous state on failure.  Otherwise
device-mapper could end up using the old table with settings from the
unused table.

Do not update the mapped device in dm_set_zones_restrictions(). Wait
till after dm_table_set_restrictions() is sure to succeed to update the
md zoned settings. Do the same with the dax settings, and if
dm_revalidate_zones() fails, restore the original queue limits.

Fixes: 7f91ccd8a608d ("dm: Call dm_revalidate_zones() after setting the queue limits")
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 35100a435c88ba6388c678c3dd17d7def2ab5333..279f1e024796e7d41e5fa8439545eceaf1d020f3 100644 (file)
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1835,6 +1835,7 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
                              struct queue_limits *limits)
 {
        int r;
+       struct queue_limits old_limits;
 
        if (!dm_table_supports_nowait(t))
                limits->features &= ~BLK_FEAT_NOWAIT;
@@ -1861,16 +1862,11 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
        if (dm_table_supports_flush(t))
                limits->features |= BLK_FEAT_WRITE_CACHE | BLK_FEAT_FUA;
 
-       if (dm_table_supports_dax(t, device_not_dax_capable)) {
+       if (dm_table_supports_dax(t, device_not_dax_capable))
                limits->features |= BLK_FEAT_DAX;
-               if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
-                       set_dax_synchronous(t->md->dax_dev);
-       } else
+       else
                limits->features &= ~BLK_FEAT_DAX;
 
-       if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
-               dax_write_cache(t->md->dax_dev, true);
-
        /* For a zoned table, setup the zone related queue attributes. */
        if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
            (limits->features & BLK_FEAT_ZONED)) {
@@ -1882,7 +1878,8 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
        if (dm_table_supports_atomic_writes(t))
                limits->features |= BLK_FEAT_ATOMIC_WRITES;
 
-       r = queue_limits_set(q, limits);
+       old_limits = queue_limits_start_update(q);
+       r = queue_limits_commit_update(q, limits);
        if (r)
                return r;
 
@@ -1893,10 +1890,21 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
        if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
            (limits->features & BLK_FEAT_ZONED)) {
                r = dm_revalidate_zones(t, q);
-               if (r)
+               if (r) {
+                       queue_limits_set(q, &old_limits);
                        return r;
+               }
        }
 
+       if (IS_ENABLED(CONFIG_BLK_DEV_ZONED))
+               dm_finalize_zone_settings(t, limits);
+
+       if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
+               set_dax_synchronous(t->md->dax_dev);
+
+       if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
+               dax_write_cache(t->md->dax_dev, true);
+
        dm_update_crypto_profile(q, t);
        return 0;
 }

diff --git a/drivers/md/dm-zone.c b/drivers/md/dm-zone.c
index 20edd3fabbabfe622783030b6106de2a9b890fcf..681058feb63b5ab718a4f2e10ef101cae7a9a76e 100644 (file)
--- a/drivers/md/dm-zone.c
+++ b/drivers/md/dm-zone.c
@@ -340,12 +340,8 @@ int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
         * mapped device queue as needing zone append emulation.
         */
        WARN_ON_ONCE(queue_is_mq(q));
-       if (dm_table_supports_zone_append(t)) {
-               clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
-       } else {
-               set_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
+       if (!dm_table_supports_zone_append(t))
                lim->max_hw_zone_append_sectors = 0;
-       }
 
        /*
         * Determine the max open and max active zone limits for the mapped
@@ -383,9 +379,6 @@ int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
                lim->zone_write_granularity = 0;
                lim->chunk_sectors = 0;
                lim->features &= ~BLK_FEAT_ZONED;
-               clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
-               md->nr_zones = 0;
-               disk->nr_zones = 0;
                return 0;
        }
 
@@ -408,6 +401,23 @@ int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
        return 0;
 }
 
+void dm_finalize_zone_settings(struct dm_table *t, struct queue_limits *lim)
+{
+       struct mapped_device *md = t->md;
+
+       if (lim->features & BLK_FEAT_ZONED) {
+               if (dm_table_supports_zone_append(t))
+                       clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
+               else
+                       set_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
+       } else {
+               clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
+               md->nr_zones = 0;
+               md->disk->nr_zones = 0;
+       }
+}
+
+
 /*
  * IO completion callback called from clone_endio().
  */

diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index a0a8ff119815804089274ee58356aa4717aa0e71..e5d3a9f46a912c49ab80fd066bac155df88aa0d4 100644 (file)
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -102,6 +102,7 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
 int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
                struct queue_limits *lim);
 int dm_revalidate_zones(struct dm_table *t, struct request_queue *q);
+void dm_finalize_zone_settings(struct dm_table *t, struct queue_limits *lim);
 void dm_zone_endio(struct dm_io *io, struct bio *clone);
 #ifdef CONFIG_BLK_DEV_ZONED
 int dm_blk_report_zones(struct gendisk *disk, sector_t sector,