There were multiple places in dm's __bind() function where it could fail and not completely roll back, leaving the device using the the old table, but with device limits and resources from the new table. Additionally, unused mempools for request-based devices were not always freed immediately. Finally, there were a number of issues with switching zoned tables that emulate zone append (in other words, dm-crypt on top of zoned devices). dm_blk_report_zones() could be called while the device was suspended and modifying zoned resources or could possibly fail to end a srcu read section. More importantly, blk_revalidate_disk_zones() would never get called when updating a zoned table. This could cause the dm device to see the wrong zone write offsets, not have a large enough zwplugs reserved in its mempool, or read invalid memory when checking the conventional zones bitmap. This patchset fixes these issues. It deals with the problems around blk_revalidate_disk_zones() by only calling it for devices that have no zone write plug resources. This will always correctly update the zoned settings. If a device has zone write plug resources, calling blk_revalidate_disk_zones() will not correctly update them in many cases, so DM simply doesn't call it for devices with zone write plug resources. Instead of allowing people to load tables that can break the device, like currently happens, DM disallosw any table reloads that change the zoned setting for devices that already have zone write plug resources. Specifically, if a device already has zone plug resources allocated, it can only switch to another zoned table that also emulates zone append. Also, it cannot change the device size or the zone size. There are some tweaks to make sure that a device can always switch to an error target. Changes in V2: - Made queue_limits_set() optionally return the old limits (grabbed while holding the limits_lock), and used this in dm_table_set_restrictions() - dropped changes to disk_free_zone_resources() and the blk_revalidate_disk_zones() code path (removed patches 0005 & 0006) - Instead of always calling blk_revalidate_disk_zones(), disallow changes that would change zone settings if the device has zone write plug resources (final patch). Benjamin Marzinski (6): dm: don't change md if dm_table_set_restrictions() fails dm: free table mempools if not used in __bind block: make queue_limits_set() optionally return old limits dm: handle failures in dm_table_set_restrictions dm: fix dm_blk_report_zones dm: limit swapping tables for devices with zone write plugs block/blk-settings.c | 9 ++++- drivers/md/dm-core.h | 1 + drivers/md/dm-table.c | 66 ++++++++++++++++++++++++++------- drivers/md/dm-zone.c | 84 +++++++++++++++++++++++++++++------------- drivers/md/dm.c | 36 +++++++++++------- drivers/md/dm.h | 6 +++ drivers/md/md-linear.c | 2 +- drivers/md/raid0.c | 2 +- drivers/md/raid1.c | 2 +- drivers/md/raid10.c | 2 +- drivers/md/raid5.c | 2 +- include/linux/blkdev.h | 3 +- 12 files changed, 154 insertions(+), 61 deletions(-) -- 2.48.1
