kernel/git/next/linux-next.git/drivers/md/dm-zoned-metadata.c, branch akpm-base

mm: shrinkers: provide shrinkers with names

2022-06-27T20:45:17+00:00

Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: -[:]- For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin Cc: Christophe JAILLET Cc: Dave Chinner Cc: Hillf Danton Cc: Kent Overstreet Cc: Muchun Song Signed-off-by: Andrew Morton

dm-zoned: remove the ->name field in struct dmz_dev

2022-03-02T17:15:35+00:00

Just use the %pg format specifier to print the block device name directly. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Damien Le Moal Signed-off-by: Mike Snitzer

block: pass a block_device and opf to bio_alloc

2022-02-02T14:49:59+00:00

Pass the block_device and operation that we plan to use this bio for to bio_alloc to optimize the assignment. NULL/0 can be passed, both for the passthrough case on a raw request_queue and to temporarily avoid refactoring some nasty code. Also move the gfp_mask argument after the nr_vecs argument for a much more logical calling convention matching what most of the kernel does. Signed-off-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de Signed-off-by: Jens Axboe

dm: bio_alloc can't fail if it is allowed to sleep

2022-02-02T14:49:59+00:00

Remove handling of NULL returns from sleeping bio_alloc calls given that those can't fail. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220124091107.642561-6-hch@lst.de Signed-off-by: Jens Axboe

dm zoned: check zone capacity

2021-06-04T16:07:28+00:00

The dm-zoned target cannot support zoned block devices with zones that have a capacity smaller than the zone size (e.g. NVMe zoned namespaces) due to the current chunk zone mapping implementation as it is assumed that zones and chunks have the same size with all blocks usable. If a zoned drive is found to have zones with a capacity different from the zone size, fail the target initialization. Signed-off-by: Damien Le Moal Cc: stable@vger.kernel.org # v5.9+ Signed-off-by: Mike Snitzer

block: use an on-stack bio in blkdev_issue_flush

2021-01-27T16:51:48+00:00

There is no point in allocating memory for a synchronous flush. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Acked-by: Damien Le Moal Signed-off-by: Jens Axboe

dm zoned: Fix zone reclaim trigger

2020-07-08T16:21:53+00:00

Only triggering reclaim based on the percentage of unmapped cache zones can fail to detect cases where reclaim is needed, e.g. if the target has only 2 or 3 cache zones and only one unmapped cache zone, the percentage of free cache zones is higher than DMZ_RECLAIM_LOW_UNMAP_ZONES (30%) and reclaim does not trigger. This problem, combined with the fact that dmz_schedule_reclaim() is called from dmz_handle_bio() without the map lock held, leads to a race between zone allocation and dmz_should_reclaim() result. Depending on the workload applied, this race can lead to the write path waiting forever for a free zone without reclaim being triggered. Fix this by moving dmz_schedule_reclaim() inside dmz_alloc_zone() under the map lock. This results in checking the need for zone reclaim whenever a new data or buffer zone needs to be allocated. Also fix dmz_reclaim_percentage() to always return 0 if the number of unmapped cache (or random) zones is less than or equal to 1. Suggested-by: Shin'ichiro Kawasaki Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Signed-off-by: Mike Snitzer

dm zoned: Fix reclaim zone selection

2020-06-19T16:29:39+00:00

When dm zoned has multiple devices, random zones are never selected for reclaim if all reserved sequential write zones are in use and no sequential write required zones can be selected for reclaim. This can lead to deadlocks as selecting a cache zone allows reclaiming a sequential zone, ensuring forward progress. Fix this by always defaulting to selecting a random zone when no sequential write required zone can be selected. [Damien: fix commit message] Signed-off-by: Shin'ichiro Kawasaki Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Signed-off-by: Mike Snitzer

dm zoned: Fix random zone reclaim selection

2020-06-19T16:28:23+00:00

Commit 2094045fe5b5 ("dm zoned: prefer full zones for reclaim") modified dmz_get_rnd_zone_for_reclaim() to add a search for the buffer zone with the heaviest weight as an optimal candidate for reclaim. This modification uses the zone pointer variabl "last" which is set only once and never modified as zones are scanned, resulting in the search being inefective. Furthermore, if the selected buffer zone at the end of the search loop is active or already locked for reclaim, dmz_get_rnd_zone_for_reclaim() returns NULL even if other random zones with a lesser weight can be reclaimed. To fix the search and to guarantee that reclaim can make forward progress, fix dmz_get_rnd_zone_for_reclaim() loop to correctly find the buffer zone with the heaviest weight using the variable maxw_z. Also make sure to fallback to finding the first random zone that can be reclaimed if this best candidate zone cannot be reclaimed. While at it, also fix the device index check to consider only random zones, ignoring cache zones belonging to the cache device if one is used as that device does not have a reclaim process. Fixes: 2094045fe5b5 ("dm zoned: prefer full zones for reclaim") Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Signed-off-by: Mike Snitzer

dm zoned: Fix metadata zone size check

2020-06-19T16:21:57+00:00

When dm zoned has multiple devices, metadata is on the cache device, not in random zones of the zoned devices. Then the number of metadata zones shall be checked with the number of cache zones, not random zones. Fixes: 34f5affd04c4 ("dm zoned: separate random and cache zones") Signed-off-by: Shin'ichiro Kawasaki Reviewed-by: Damien Le Moal Signed-off-by: Mike Snitzer