kernel.git/drivers/lightnvm/pblk.h, branch linux-5.0.y

lightnvm: pblk: do not overwrite ppa list with meta list

2018-12-11T19:22:35Z

Ehen using pblk with 0 sized metadata both ppa list and meta list points to the same memory since pblk_dma_meta_size() returns 0 in that case. This patch fix that issue by ensuring that pblk_dma_meta_size() always returns space equal to sizeof(struct pblk_sec_meta) and thus ppa list and meta list points to different memory address. Even that in that case drive does not really care about meta_list pointer, this is the easiest way to fix that issue without introducing changes in many places in the code just for 0 sized metadata case. The same approach needs to be also done for pblk_get_sec_meta() since we also cannot point to the same memory address in meta buffer when we are using it for pblk recovery process Reported-by: Hans Holmberg Tested-by: Hans Holmberg Signed-off-by: Igor Konopko Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: support packed metadata

2018-12-11T19:22:35Z

pblk performs recovery of open lines by storing the LBA in the per LBA metadata field. Recovery therefore only works for drives that has this field. This patch adds support for packed metadata, which store l2p mapping for open lines in last sector of every write unit and enables drives without per IO metadata to recover open lines. After this patch, drives with OOB size <16B will use packed metadata and metadata size larger than16B will continue to use the device per IO metadata. Reviewed-by: Javier González Signed-off-by: Igor Konopko Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: dynamic DMA pool entry size

2018-12-11T19:22:35Z

Currently lightnvm and pblk uses single DMA pool, for which the entry size always is equal to PAGE_SIZE. The contents of each entry allocated from the DMA pool consists of a PPA list (8bytes * 64), leaving 56bytes * 64 space for metadata. Since the metadata field can be bigger, such as 128 bytes, the static size does not cover this use-case. This patch adds support for I/O metadata above 56 bytes by changing DMA pool size based on device meta size and allows pblk to use OOB metadata >=16B. Reviewed-by: Javier González Signed-off-by: Igor Konopko Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: add helpers for OOB metadata

2018-12-11T19:22:35Z

pblk currently assumes that size of OOB metadata on drive is always equal to size of pblk_sec_meta struct. This commit add helpers which will allow to handle different sizes of OOB metadata on drive in the future. After this patch only OOB metadata equal to 16 bytes is supported. Reviewed-by: Javier González Signed-off-by: Igor Konopko Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: move lba list to partial read context

2018-12-11T19:22:34Z

Currently DMA allocated memory is reused on partial read for lba_list_mem and lba_list_media arrays. In preparation for dynamic DMA pool sizes we need to move this arrays into pblk_pr_ctx structures. Reviewed-by: Javier González Signed-off-by: Igor Konopko Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: set conservative threshold for user writes

2018-12-11T19:22:33Z

In a worst-case scenario (random writes), OP% of sectors in each line will be invalid, and we will then need to move data out of 100/OP% lines to free a single line. So, to prevent the possibility of running out of lines, temporarily block user writes when there is less than 100/OP% free lines. Also ensure that pblk creation does not produce instances with insufficient over provisioning. Insufficient over-provising is not a problem on real hardware, but often an issue when running QEMU simulations (with few lines). 100 lines is enough to create a sane instance with the standard (11%) over provisioning. Signed-off-by: Hans Holmberg Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: stop writes gracefully when running out of lines

2018-12-11T19:22:33Z

If mapping fails (i.e. when running out of lines), handle the error and stop writing. Signed-off-by: Hans Holmberg Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: guarantee that backpointer is respected on writer stall

2018-10-09T14:25:08Z

pblk's write buffer must guarantee that it respects the device's constrains for reads (i.e., mw_cunits). This is done by maintaining a backpointer that updates the L2P table as entries wrap up, making them point to the media instead of pointing to the write buffer. This mechanism can race in case that the write thread stalls, as the write pointer will protect the last written entry, thus disregarding the read constrains. This patch adds an extra check on wrap up, making sure that the threshold is respected at all times, preventing new entries to overwrite committed data, also in case of write thread stall. Reported-by: Heiner Litz Signed-off-by: Javier González Reviewed-by: Heiner Litz Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: move ring buffer alloc/free rb init

2018-10-09T14:25:08Z

pblk's read/write buffer currently takes a buffer and its size and uses it to create the metadata around it to use it as a ring buffer. This puts the responsibility of allocating/freeing ring buffer memory on the ring buffer user. Instead, move it inside of the ring buffer helpers (pblk-rb.c). This simplifies creation/destruction routines. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: encapsulate rb pointer operations

2018-10-09T14:25:08Z

pblk's read/write buffer is always a power-of-2, thus wrapping up the buffer can be done with a bit mask. Since this is an implementation detail internal to the write buffer, make a helper that hides pointer increment + wrap, and allows to transparently relax this assumption in the future. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe