kernel/git/stable/linux.git/drivers/lightnvm/pblk.h, branch master

remove the lightnvm subsystem

2021-08-14T21:54:09+00:00

Lightnvm supports the OCSSD 1.x and 2.0 specs which were early attempts to produce Open Channel SSDs and never made it into the NVMe spec proper. They have since been superceeded by NVMe enhancements such as ZNS support. Remove the support per the deprecation schedule. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210812132308.38486-1-hch@lst.de Reviewed-by: Matias Bjørling Reviewed-by: Javier González Signed-off-by: Jens Axboe

lightnvm: pblk: use kvmalloc for metadata

2019-08-06T14:20:10+00:00

There is no reason now not to use kvmalloc, so replace the internal metadata allocation scheme. Reviewed-by: Javier González Reviewed-by: Christoph Hellwig Signed-off-by: Hans Holmberg Signed-off-by: Jens Axboe

lightnvm: move metadata mapping to lower level driver

2019-08-06T14:20:10+00:00

Now that blk_rq_map_kern can map both kmem and vmem, move internal metadata mapping down to the lower level driver. Reviewed-by: Javier González Reviewed-by: Christoph Hellwig Signed-off-by: Hans Holmberg Signed-off-by: Jens Axboe

lightnvm: pblk: simplify partial read path

2019-05-06T16:19:19+00:00

This patch changes the approach to handling partial read path. In old approach merging of data from round buffer and drive was fully made by drive. This had some disadvantages - code was complex and relies on bio internals, so it was hard to maintain and was strongly dependent on bio changes. In new approach most of the handling is done mostly by block layer functions such as bio_split(), bio_chain() and generic_make request() and generally is less complex and easier to maintain. Below some more details of the new approach. When read bio arrives, it is cloned for pblk internal purposes. All the L2P mapping, which includes copying data from round buffer to bio and thus bio_advance() calls is done on the cloned bio, so the original bio is untouched. If we found that we have partial read case, we still have original bio untouched, so we can split it and continue to process only first part of it in current context, when the rest will be called as separate bio request which is passed to generic_make_request() for further processing. Signed-off-by: Igor Konopko Reviewed-by: Heiner Litz Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: IO path reorganization

2019-05-06T16:19:19+00:00

This patch is made in order to prepare read path for new approach to partial read handling, which is simpler in compare with previous one. The most important change is to move the handling of completed and failed bio from the pblk_make_rq() to particular read and write functions. This is needed, since after partial read path changes, sometimes completed/failed bio will be different from original one, so we cannot do this any longer in pblk_make_rq(). Other changes are small read path refactor in order to reduce the size of the following patch with partial read changes. Generally the goal of this patch is not to change the functionality, but just to prepare the code for the following changes. Signed-off-by: Igor Konopko Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: GC error handling

2019-05-06T16:19:18+00:00

Currently when there is an IO error (or similar) on GC read path, pblk still move the line, which was currently under GC process to free state. Such a behaviour can lead to silent data mismatch issue. With this patch, the line which was under GC process on which some IO errors occurred, will be putted back to closed state (instead of free state as it was without this patch) and the L2P mapping for such a failed sectors will not be updated. Then in case of any user IOs to such a failed sectors, pblk would be able to return at least real IO error instead of stale data as it is right now. Signed-off-by: Igor Konopko Reviewed-by: Javier González Reviewed-by: Hans Holmberg Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: remove internal IO timeout

2019-05-06T16:19:18+00:00

Currently during pblk padding, there is internal IO timeout introduced, which is smaller than default NVMe timeout. This can lead to various use-after-free issues. Since in case of any IO timeouts NVMe and block layer will handle timeout by themselves and report it back to use, there is no need to keep this internal timeout in pblk. Signed-off-by: Igor Konopko Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: remove unused smeta_ssec field

2019-05-06T16:19:17+00:00

smeta_ssec field in pblk_line is never used after it was replaced by the function pblk_line_smeta_start(). Signed-off-by: Igor Konopko Reviewed-by: Hans Holmberg Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: reduce L2P memory footprint

2019-05-06T16:19:16+00:00

Currently L2P map size is calculated based on the total number of available sectors, which is redundant, since it contains mapping for overprovisioning as well (11% by default). Change this size to the real capacity and thus reduce the memory footprint significantly - with default op value it is approx. 110MB of DRAM less for every 1TB of media. Signed-off-by: Igor Konopko Reviewed-by: Hans Holmberg Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: fix race condition on GC

2019-02-11T15:18:08+00:00

This patch fixes a race condition where a write is mapped to the last sectors of a line. The write is synced to the device but the L2P is not updated yet. When the line is garbage collected before the L2P update is performed, the sectors are ignored by the GC logic and the line is freed before all sectors are moved. When the L2P is finally updated, it contains a mapping to a freed line, subsequent reads of the corresponding LBAs fail. This patch introduces a per line counter specifying the number of sectors that are synced to the device but have not been updated in the L2P. Lines with a counter of greater than zero will not be selected for GC. Signed-off-by: Heiner Litz Reviewed-by: Hans Holmberg Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe