| Message ID | 20240606082147.96422-2-dlemoal@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix DM zone resource limits stacking | expand |
On Thu, Jun 06, 2024 at 05:21:44PM +0900, Damien Le Moal wrote: > Make sure that the zone resource limits of a zoned block device are > correct by checking that: > (a) If the device has a max active zones limit, make sure that the max > open zones limit is lower than the max active zones limit. > (b) If the device has zone resource limits, check that the limits > values are lower than the number of sequential zones of the device. > If it is not, assume that the zoned device has no limits by setting > the limits to 0. > > For (a), a check is added to blk_validate_zoned_limits() and an error > returned if the max open zones limit exceeds the value of the max active > zone limit (if there is one). > > For (b), given that we need the number of sequential zones of the zoned > device, this check is added to disk_update_zone_resources(). This is > safe to do as that function is executed with the disk queue frozen and > the check executed after queue_limits_start_update() which takes the > queue limits lock. Of note is that the early return in this function > for zoned devices that do not use zone write plugging (e.g. DM devices > using native zone append) is moved to after the new check and adjustment > of the zone resource limits so that the check applies to any zoned > device. > > Signed-off-by: Damien Le Moal <dlemoal@kernel.org> > Reviewed-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> > --- Reviewed-by: Niklas Cassel <cassel@kernel.org>
diff --git a/block/blk-settings.c b/block/blk-settings.c index effeb9a639bb..607f888fe93b 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -80,6 +80,14 @@ static int blk_validate_zoned_limits(struct queue_limits *lim) if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED))) return -EINVAL; + /* + * Given that active zones include open zones, the maximum number of + * open zones cannot be larger than the maximum number of active zones. + */ + if (lim->max_active_zones && + lim->max_open_zones > lim->max_active_zones) + return -EINVAL; + if (lim->zone_write_granularity < lim->logical_block_size) lim->zone_write_granularity = lim->logical_block_size; diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 52abebf56027..8f89705f5e1c 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -1647,8 +1647,22 @@ static int disk_update_zone_resources(struct gendisk *disk, return -ENODEV; } + lim = queue_limits_start_update(q); + + /* + * Some devices can advertize zone resource limits that are larger than + * the number of sequential zones of the zoned block device, e.g. a + * small ZNS namespace. For such case, assume that the zoned device has + * no zone resource limits. + */ + nr_seq_zones = disk->nr_zones - nr_conv_zones; + if (lim.max_open_zones >= nr_seq_zones) + lim.max_open_zones = 0; + if (lim.max_active_zones >= nr_seq_zones) + lim.max_active_zones = 0; + if (!disk->zone_wplugs_pool) - return 0; + goto commit; /* * If the device has no limit on the maximum number of open and active @@ -1657,9 +1671,6 @@ static int disk_update_zone_resources(struct gendisk *disk, * dynamic zone write plug allocation when simultaneously writing to * more zones than the size of the mempool. */ - lim = queue_limits_start_update(q); - - nr_seq_zones = disk->nr_zones - nr_conv_zones; pool_size = max(lim.max_open_zones, lim.max_active_zones); if (!pool_size) pool_size = min(BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE, nr_seq_zones); @@ -1673,6 +1684,7 @@ static int disk_update_zone_resources(struct gendisk *disk, lim.max_open_zones = 0; } +commit: return queue_limits_commit_update(q, &lim); }
Make sure that the zone resource limits of a zoned block device are correct by checking that: (a) If the device has a max active zones limit, make sure that the max open zones limit is lower than the max active zones limit. (b) If the device has zone resource limits, check that the limits values are lower than the number of sequential zones of the device. If it is not, assume that the zoned device has no limits by setting the limits to 0. For (a), a check is added to blk_validate_zoned_limits() and an error returned if the max open zones limit exceeds the value of the max active zone limit (if there is one). For (b), given that we need the number of sequential zones of the zoned device, this check is added to disk_update_zone_resources(). This is safe to do as that function is executed with the disk queue frozen and the check executed after queue_limits_start_update() which takes the queue limits lock. Of note is that the early return in this function for zoned devices that do not use zone write plugging (e.g. DM devices using native zone append) is moved to after the new check and adjustment of the zone resource limits so that the check applies to any zoned device. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> --- block/blk-settings.c | 8 ++++++++ block/blk-zoned.c | 20 ++++++++++++++++---- 2 files changed, 24 insertions(+), 4 deletions(-)