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path: root/drivers/lightnvm/pblk-write.c
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2019-05-06lightnvm: pblk: kick writer on write recovery pathIgor Konopko1-0/+1
In case of write recovery path, there is a chance that writer thread is not active, kick immediately instead of waiting for timer. Signed-off-by: Igor Konopko <igor.j.konopko@intel.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-11lightnvm: pblk: fix race condition on GCHeiner Litz1-0/+1
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 <hlitz@ucsc.edu> Reviewed-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Reviewed-by: Javier González <javier@javigon.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-11lightnvm: pblk: support packed metadataIgor Konopko1-4/+5
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 <javier@cnexlabs.com> Signed-off-by: Igor Konopko <igor.j.konopko@intel.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-11lightnvm: pblk: stop writes gracefully when running out of linesHans Holmberg1-10/+20
If mapping fails (i.e. when running out of lines), handle the error and stop writing. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Reviewed-by: Javier González <javier@javigon.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-11lightnvm: pblk: account for write error sectors in emetaHans Holmberg1-2/+15
Lines inflicted with write errors lines might be recovered if they have not been recycled after write error garbage collection. Ensure that the emeta accounting of valid lbas is correct for such lines to avoid recovery inconsistencies. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Reviewed-by: Javier González <javier@javigon.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-11lightnvm: pblk: fix resubmission of overwritten write err lbasHans Holmberg1-3/+5
Make sure we only look up valid lba addresses on the resubmission path. If an lba is invalidated in the write buffer, that sector will be submitted to disk (as it is already mapped to a ppa), and that write might fail, resulting in a crash when trying to look up the lba in the mapping table (as the lba is marked as invalid). Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Reviewed-by: Javier González <javier@javigon.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: encapsulate rb pointer operationsJavier González1-5/+2
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 <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: add SPDX license tagJavier González1-0/+1
Add GLP-2.0 SPDX license tag to all pblk files Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: encapsulate rqd dma allocationsJavier González1-13/+2
dma allocations for ppa_list and meta_list in rqd are replicated in several places across the pblk codebase. Make helpers to encapsulate creation and deletion to simplify the code. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: fix mapping issue on failed writesHans Holmberg1-11/+1
On 1.2-devices, the mapping-out of remaning sectors in the failed-write's block can result in an infinite loop, stalling the write pipeline, fix this. Fixes: 6a3abf5beef6 ("lightnvm: pblk: rework write error recovery path") Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: add trace events for chunk statesHans Holmberg1-2/+8
Introduce trace points for tracking chunk states in pblk - this is useful for inspection of the entire state of the drive, and real handy for both fw and pblk debugging. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: remove debug from pblk_[down/up]_pageMatias Bjørling1-3/+3
Remove the debug only iteration within __pblk_down_page, which then allows us to reduce the number of arguments down to pblk and the parallel unit from the functions that calls it. Simplifying the callers logic considerably. Also, rename the functions pblk_[down/up]_page to pblk_[down/up]_chunk, to communicate that it manages the write pointer of the chunk. Note that it also protects the parallel unit such that at most one chunk is active per parallel unit. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: remove unused parameters in pblk_up_rqHans Holmberg1-3/+2
The parameters nr_ppas and ppa_list are not used, so remove them. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: introduce nvm_rq_to_ppa_listHans Holmberg1-10/+8
There is a number of places in the lightnvm subsystem where the user iterates over the ppa list. Before iterating, the user must know if it is a single or multiple LBAs due to vector commands using either the nvm_rq ->ppa_addr or ->ppa_list fields on command submission, which leads to open-coding the if/else statement. Instead of having multiple if/else's, move it into a function that can be called by its users. A nice side effect of this cleanup is that this patch fixes up a bunch of cases where we don't consider the single-ppa case in pblk. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: fix comment typoJavier González1-1/+1
Fix comment typo Decrese -> Decrease Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: improve line helpersJavier González1-2/+2
The current helper to obtain a line from a ppa returns the line id, which requires its users to explicitly retrieve the pointer to the line with the id. Make 2 different helpers: one returning the line id and one returning the line directly. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: pblk: fix race condition on metadata I/OJavier González1-7/+7
In pblk, when a new line is allocated, metadata for the previously written line is scheduled. This is done through a fixed memory region that is shared through time and contexts across different lines and therefore protected by a lock. Unfortunately, this lock is not properly covering all the metadata used for sharing this memory regions, resulting in a race condition. This patch fixes this race condition by protecting this metadata properly. Fixes: dd2a43437337 ("lightnvm: pblk: sched. metadata on write thread") Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-09lightnvm: combine 1.2 and 2.0 command flagsMatias Bjørling1-1/+1
Add nvm_set_flags helper to enable core to appropriately set the command flags for read/write/erase depending on which version a drive supports. The flags arguments can be distilled into the access hint, scrambling, and program/erase suspend. Replace the access hint with a "is_seq" parameter. The rest of the flags are dependent on the command opcode, which is trivial to detect and set. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-13lightnvm: pblk: expose generic disk name on pr_* msgsMatias Bjørling1-10/+11
The error messages in pblk does not say which pblk instance that a message occurred from. Update each error message to reflect the instance it belongs to, and also prefix it with pblk, so we know the message comes from the pblk module. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-13lightnvm: move NVM_DEBUG to pblkMatias Bjørling1-7/+7
There is no users of CONFIG_NVM_DEBUG in the LightNVM subsystem. All users are in pblk. Rename NVM_DEBUG to NVM_PBLK_DEBUG and enable only for pblk. Also fix up the CONFIG_NVM_PBLK entry to follow the code style for Kconfig files. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-01lightnvm: pblk: garbage collect lines with failed writesHans Holmberg1-0/+2
Write failures should not happen under normal circumstances, so in order to bring the chunk back into a known state as soon as possible, evacuate all the valid data out of the line and let the fw judge if the block can be written to in the next reset cycle. Do this by introducing a new gc list for lines with failed writes, and ensure that the rate limiter allocates a small portion of the write bandwidth to get the job done. The lba list is saved in memory for use during gc as we cannot gurantee that the emeta data is readable if a write error occurred. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-01lightnvm: pblk: rework write error recovery pathHans Holmberg1-91/+176
The write error recovery path is incomplete, so rework the write error recovery handling to do resubmits directly from the write buffer. When a write error occurs, the remaining sectors in the chunk are mapped out and invalidated and the request inserted in a resubmit list. The writer thread checks if there are any requests to resubmit, scans and invalidates any lbas that have been overwritten by later writes and resubmits the failed entries. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-30lightnvm: convert to bioset_init()/mempool_init()Kent Overstreet1-4/+4
Convert lightnvm to embedded bio sets. Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-29lightnvm: simplify geometry structureJavier González1-1/+1
Currently, the device geometry is stored redundantly in the nvm_id and nvm_geo structures at a device level. Moreover, when instantiating targets on a specific number of LUNs, these structures are replicated and manually modified to fit the instance channel and LUN partitioning. Instead, create a generic geometry around nvm_geo, which can be used by (i) the underlying device to describe the geometry of the whole device, and (ii) instances to describe their geometry independently. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-05lightnvm: pblk: clear flush point on completed writesHans Holmberg1-1/+16
Move completion of syncs and clearing of flush points to the write completion path - this ensures that the data has been comitted to the media before completing bios containing syncs. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-05lightnvm: pblk: rename sync_point to flush_pointHans Holmberg1-1/+1
Sync point is a really confusing name for keeping track of the last entry that needs to be flushed so change the name to to flush_point instead. Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-05lightnvm: use internal pblk methodsMatias Bjørling1-2/+2
Now that rrpc has been removed, the only users of the ppa helpers is pblk. However, pblk already defines similar functions. Switch pblk to use the internal ones, and remove the generic ppa helpers. Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: remove I/O dependency on write pathJavier González1-80/+65
pblk schedules user I/O, metadata I/O and erases on the write path in order to minimize collisions at the media level. Until now, there has been a dependency between user and metadata I/Os that could lead to a deadlock as both take the per-LUN semaphore to schedule submission. This path removes this dependency and guarantees forward progress at a per I/O granurality. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: refactor rqd alloc/freeJavier González1-7/+0
Refactor the rqd allocation and free functions so that all I/O types can use these helper functions. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: improve naming for internal req.Javier González1-8/+8
Each request type sent to the LightNVM subsystem requires different metadata. Until now, we have tailored this metadata based on write, read and erase commands. However, pblk uses different metadata for internal writes that do not hit the write buffer. Instead of abusing the metadata for reads, create a new request type - internal write to improve code readability. In the process, create internal values for each I/O type instead of abusing the READ/WRITE macros, as suggested by Christoph. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: allocate bio size more accuratelyJavier González1-10/+10
Wait until we know the exact number of ppas to be sent to the device, before allocating the bio. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: put bio on bio completionJavier González1-7/+1
Simplify put bio by doing it on bio end_io instead of manually putting it on the completion path. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: remove checks on mempool alloc.Javier González1-19/+5
As part of the mempool audit on pblk, remove unnecessary mempool allocation checks on mempools. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: do not use a mempool for line bitmapsJavier González1-3/+1
pblk holds two sector bitmaps: one to keep track of the mapped sectors while the line is active and another one to keep track of the invalid sectors. The latter is kept during the whole live of the line, until it is recycled. Since we cannot guarantee forward progress for the mempool in this case, get rid of the mempool and simply allocate memory through kmalloc. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: simplify work_queue mempoolJavier González1-2/+2
In pblk, we have a mempool to allocate a generic structure that we pass along workqueues. This is heavily used in the GC path in order to have enough inflight reads and fully utilize the GC bandwidth. However, the current GC path copies data to the host memory and puts it back into the write buffer. This requires a vmalloc allocation for the data and a memory copy. Thus, guaranteeing the allocation by using a mempool for the structure in itself does not give us much. Until we implement support for vector copy to avoid moving data through the host, just allocate the workqueue structure using kmalloc. This allows us to have a much smaller mempool. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: fix write I/O sync statJavier González1-1/+1
Fix stat counter to collect the right number of I/Os being synced on the completion path. Fixes: 0880a9aa2d91f ("lightnvm: pblk: delete redundant buffer pointer") Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13lightnvm: pblk: free padded entries in write bufferJavier González1-1/+6
When a REQ_FLUSH reaches pblk, the bio cannot be directly completed. Instead, data on the write buffer is flushed and the bio is completed on the completion pah. This might require some sectors to be padded in order to guarantee a successful write. This patch fixes a memory leak on the padded pages. A consequence of this bad free was that internal bios not containing data (only a flush) were not being completed. Fixes: a4bd217b4326 ("lightnvm: physical block device (pblk) target") Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-07lightnvm: pblk: remove unnecessary checksJavier González1-6/+1
Remove unnecessary checks when freeing dma memory in the completion path. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-07lightnvm: pblk: control I/O flow also on tear downJavier González1-12/+7
When removing a pblk instance, control the write I/O flow to the controller as we do in the fast path. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-30lightnvm: pblk: remove target using async. I/OsJavier González1-1/+1
When removing a pblk instance, pad the current line using asynchronous I/O. This reduces the removal time from ~1 minute in the worst case to a couple of seconds. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-30lightnvm: pblk: use vmalloc for GC data bufferJavier González1-1/+2
For now, we allocate a per I/O buffer for GC data. Since the potential size of the buffer is 256KB and GC is not in the fast path, do this allocation with vmalloc. This puts lets pressure on the memory allocator at no performance cost. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-26lightnvm: pblk: fail gracefully on irrec. errorJavier González1-1/+4
Due to user writes being decoupled from media writes because of the need of an intermediate write buffer, irrecoverable media write errors lead to pblk stalling; user writes fill up the buffer and end up in an infinite retry loop. In order to let user writes fail gracefully, it is necessary for pblk to keep track of its own internal state and prevent further writes from being placed into the write buffer. This patch implements a state machine to keep track of internal errors and, in case of failure, fail further user writes in an standard way. Depending on the type of error, pblk will do its best to persist buffered writes (which are already acknowledged) and close down on a graceful manner. This way, data might be recovered by re-instantiating pblk. Such state machine paves out the way for a state-based FTL log. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-26lightnvm: pblk: set mempool and workqueue params.Javier González1-2/+3
Make constants to define sizes for internal mempools and workqueues. In this process, adjust the values to be more meaningful given the internal constrains of the FTL. In order to do this for workqueues, separate the current auxiliary workqueue into two dedicated workqueues to manage lines being closed and bad blocks. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-26lightnvm: pblk: cleanup unnecessary codeJavier González1-6/+0
Cleanup unnecessary headers and code lines. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-26lightnvm: pblk: simplify meta. memory allocationJavier González1-1/+2
smeta size will always be suitable for a kmalloc allocation. Simplify the code and leave the vmalloc fallback only for emeta, where the pblk configuration has an impact. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-26lightnvm: pblk: delete redundant buffer pointerJavier González1-12/+1
After refactoring the metadata path, the backpointer controlling synced I/Os in a line becomes unnecessary; metadata is scheduled on the write thread, thus we know when the end of the line is reached and act on it directly. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-26lightnvm: pblk: sched. metadata on write threadJavier González1-23/+228
At the moment, line metadata is persisted on a separate work queue, that is kicked each time that a line is closed. The assumption when designing this was that freeing the write thread from creating a new write request was better than the potential impact of writes colliding on the media (user I/O and metadata I/O). Experimentation has proven that this assumption is wrong; collision can cause up to 25% of bandwidth and introduce long tail latencies on the write thread, which potentially cause user write threads to spend more time spinning to get a free entry on the write buffer. This patch moves the metadata logic to the write thread. When a line is closed, remaining metadata is written in memory and is placed on a metadata queue. The write thread then takes the metadata corresponding to the previous line, creates the write request and schedules it to minimize collisions on the media. Using this approach, we see that we can saturate the media's bandwidth, which helps reducing both write latencies and the spinning time for user writer threads. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-26lightnvm: pblk: generalize erase pathJavier González1-50/+59
Erase I/Os are scheduled with the following goals in mind: (i) minimize LUNs collisions with write I/Os, and (ii) even out the price of erasing on every write, instead of putting all the burden on when garbage collection runs. This works well on the current design, but is specific to the default mapping algorithm. This patch generalizes the erase path so that other mapping algorithms can select an arbitrary line to be erased instead. It also gets rid of the erase semaphore since it creates jittering for user writes. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-09block: switch bios to blk_status_tChristoph Hellwig1-1/+1
Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-23lightnvm: pblk: fix erase counters on error failJavier González1-2/+2
When block erases fail, these blocks are marked bad. The number of valid blocks in the line was not updated, which could cause an infinite loop on the erase path. Fix this atomic counter and, in order to avoid taking an irq lock on the interrupt context, make the erase counters atomic too. Also, in the case that a significant number of blocks become bad in a line, the result is the double shared metadata buffer (emeta) to stop the pipeline until all metadata is flushed to the media. Increase the number of metadata lines from 2 to 4 to avoid this case. Fixes: a4bd217b4326 "lightnvm: physical block device (pblk) target" Signed-off-by: Javier González <javier@cnexlabs.com> Reviewed-by: Matias Bjørling <matias@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@fb.com>