On 4/11/25 04:49, Benjamin Marzinski wrote: > 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. > > Also, 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 initially > setting up a zoned table and creating 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. > > Finally, any DM device created on top of a device emulating zone appeads > will automatically have zone write plug resources created for it, since > max_hw_zone_append_sectors will always be 0 for a device stacked on top > of a device max_hw_zone_append_sectors = 0 > > 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. Finally, it deals with the max_hw_zone_append_sectors issue > by making sure that it is non-zero for zoned DM devices that do not need > zone write append emulation. > > Changes in V4: > - Fixed typos in 2 commit messages (patches 4 and 5) > - rephrased comment in dm_revalidate_zones() (patch 5) I gave this a quick spin and did not detect any issues. So feel free to add: Tested-by: Damien Le Moal <dlemoal@xxxxxxxxxx> -- Damien Le Moal Western Digital Research
