- 09 Oct, 2018 40 commits
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Javier González authored
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 <hlitz@ucsc.edu> Signed-off-by:
Javier González <javier@cnexlabs.com> Reviewed-by:
Matias Bjørling <mb@lightnvm.io> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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Zhoujie Wu authored
When do GC, the number of read/write sectors are determined by max_write_pgs(see gc_rq preparation in pblk_gc_line_prepare_ws). Due to max_write_pgs doesn't consider max hw sectors supported by nvme controller(128K), which leads to GC tries to read 64 * 4K in one command, and see below error caused by pblk_bio_map_addr in function pblk_submit_read_gc. [ 2923.005376] pblk: could not add page to bio [ 2923.005377] pblk: could not allocate GC bio (18446744073709551604) Signed-off-by:
Zhoujie Wu <zjwu@marvell.com> Reviewed-by:
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Wei Yongjun authored
In the too many bad blocks error handling case, we should release all the allocated resources, otherwise it will cause memory leak. Fixes: 2deeefc0 ("lightnvm: pblk: fail gracefully on line alloc. failure") Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by:
Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by:
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Javier González authored
1.2 devices exposes their data and metadata size through the separate identify command. Make sure that the NVMe LBA format does not override these values. Signed-off-by:
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Javier González authored
OCSSD 2.0 defines the amount of data that the host must buffer per chunk to guarantee reads through the geometry field mw_cunits. This value is the base that pblk uses to determine the size of its read buffer. Currently, this size is set to be the closes power-of-2 to mw_cunits times the number of parallel units available to the pblk instance for each open line (currently one). When an entry (4KB) is put in the buffer, the L2P table points to it. As the buffer wraps up, the L2P is updated to point to addresses on the device, thus guaranteeing mw_cunits at a chunk level. However, given that pblk cannot write to the device under ws_min (normally ws_opt), there might be a window in which the buffer starts wrapping up and updating L2P entries before the mw_cunits value in a chunk has been surpassed. In order not to violate the mw_cunits constrain in this case, account for ws_opt on the read buffer creation. Signed-off-by:
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Javier González authored
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:
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Javier González authored
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:
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Javier González authored
Removed unused function in pblk-rb.c Signed-off-by:
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Javier González authored
pblk exposes a sysfs interface that represents its internal state. Part of this state is the map bitmap for the current open line, which should be protected by the line lock to avoid a race when freeing the line metadata. Currently, it is not. This patch makes sure that the line state is consistent and NULL bitmap pointers are not dereferenced. Signed-off-by:
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Javier González authored
Add GLP-2.0 SPDX license tag to all pblk files Signed-off-by:
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Javier González authored
In the OCSSD 2.0 spec, each chunk reports its write pointer. This means that pblk does not need to scan open lines to find the write pointer, but instead, it can retrieve it directly (and verify it). This patch uses the write pointer on open lines to (i) recover the line up until the last written lba and (ii) reconstruct the map bitmap and rest of line metadata so that the line can be used for new data. Since the 1.2 path in lightnvm core has been re-implemented to populate the chunk structure and thus recover the write pointer on initialization, this patch removes 1.2 specific recovery, as the 2.0 path can be reused. Signed-off-by:
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Javier González authored
pblk guarantees write ordering at a chunk level through a per open chunk semaphore. At this point, since we only have an open I/O stream for both user and GC data, the semaphore is per parallel unit. For the metadata I/O that is synchronous, the semaphore is not needed as ordering is guaranteed. However, if the metadata scheme changes or multiple streams are open, this guarantee might not be preserved. This patch makes sure that all writes go through the semaphore, even for synchronous I/O. This is consistent with pblk's write I/O model. It also simplifies maintenance since changes in the metadata scheme could cause ordering issues. Signed-off-by:
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Javier González authored
pblk maintains two different metadata paths for smeta and emeta, which store metadata at the start of the line and at the end of the line, respectively. Until now, these path has been common for writing and retrieving metadata, however, as these paths diverge, the common code becomes less clear and unnecessary complicated. In preparation for further changes to the metadata write path, this patch separates the write and read paths for smeta and emeta and removes the synchronous emeta path as it not used anymore (emeta is scheduled asynchronously to prevent jittering due to internal I/Os). Signed-off-by:
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Javier González authored
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:
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Javier González authored
The lightnvm subsystem provides helpers to retrieve chunk metadata, where the target needs to provide a buffer to store the metadata. An implicit assumption is that this buffer is contiguous and can be used to retrieve the data from the device. If the device exposes too many chunks, then kmalloc might fail, thus failing instance creation. This patch removes this assumption by implementing an internal buffer in the lightnvm subsystem to retrieve chunk metadata. Targets can then use virtual memory allocations. Since this is a target API change, adapt pblk accordingly. Signed-off-by:
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Jia-Ju Bai authored
The driver may sleep with holding a spinlock. The function call paths (from bottom to top) in Linux-4.16 are: [FUNC] nvm_dev_dma_alloc(GFP_KERNEL) drivers/lightnvm/pblk-core.c, 754: nvm_dev_dma_alloc in pblk_line_submit_smeta_io drivers/lightnvm/pblk-core.c, 1048: pblk_line_submit_smeta_io in pblk_line_init_bb drivers/lightnvm/pblk-core.c, 1434: pblk_line_init_bb in pblk_line_replace_data drivers/lightnvm/pblk-recovery.c, 980: pblk_line_replace_data in pblk_recov_l2p drivers/lightnvm/pblk-recovery.c, 976: spin_lock in pblk_recov_l2p [FUNC] bio_map_kern(GFP_KERNEL) drivers/lightnvm/pblk-core.c, 762: bio_map_kern in pblk_line_submit_smeta_io drivers/lightnvm/pblk-core.c, 1048: pblk_line_submit_smeta_io in pblk_line_init_bb drivers/lightnvm/pblk-core.c, 1434: pblk_line_init_bb in pblk_line_replace_data drivers/lightnvm/pblk-recovery.c, 980: pblk_line_replace_data in pblk_recov_l2p drivers/lightnvm/pblk-recovery.c, 976: spin_lock in pblk_recov_l2p To fix these bugs, the call to pblk_line_replace_data() is moved out of the spinlock protection. These bugs are found by my static analysis tool DSAC. Signed-off-by:
Jia-Ju Bai <baijiaju1990@gmail.com> Reviewed-by:
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Hans Holmberg authored
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: 6a3abf5b ("lightnvm: pblk: rework write error recovery path") Signed-off-by:
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Hans Holmberg authored
Pblk should not create a set of global caches every time a pblk instance is created. The global caches should be made available only when there is one or more pblk instances. This patch bundles the global caches together with a kref keeping track of whether the caches should be available or not. Also, turn the global pblk lock into a mutex that explicitly protects the caches (as this was the only purpose of the lock). Signed-off-by:
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Javier González authored
If a line is padded, calculate the pad distance directly on the helper being used for this purpose. Signed-off-by:
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Javier González authored
Continuing the effort of moving 1.2 and 2.0 specific code to core, move 64_to_32 and 32_to_64 ppa helpers from pblk to core. Signed-off-by:
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Hans Holmberg authored
Trace state of chunk resets. Signed-off-by:
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Hans Holmberg authored
Add trace events for tracking pblk state changes. Signed-off-by:
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Hans Holmberg authored
Add trace events for logging for line state changes. Signed-off-by:
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Hans Holmberg authored
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:
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Matias Bjørling authored
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:
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Hans Holmberg authored
When the user data counter exceeds 32 bits, the write amplification calculation does not provide the right value. Fix this by using div64_u64 in stead of div64. Fixes: 76758390 ("lightnvm: pblk: export write amplification counters to sysfs") Signed-off-by:
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Hans Holmberg authored
The prefix when printing ppas in pblk_read_check_rand should be "rnd" not "seq", so fix this so we can differentiate between lba missmatches in random and sequential reads. Also change the print order so we align with pblk_read_check_seq, printing read lba first. Signed-off-by:
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Hans Holmberg authored
The parameters nr_ppas and ppa_list are not used, so remove them. Signed-off-by:
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Hans Holmberg authored
Line map bitmap allocations are fairly large and can fail. Allocation failures are fatal to pblk, stopping the write pipeline. To avoid this, allocate the bitmaps using a mempool instead. Mempool allocations never fail if called from a process context, and pblk *should* only allocate map bitmaps in process context, but keep the failure handling for robustness sake. Signed-off-by:
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Hans Holmberg authored
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:
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Javier González authored
If a line is recovered from open chunks, the memory structures for emeta have not necessarily been properly set on line initialization. When closing a line, make sure that emeta is consistent so that the line can be recovered on the fast path on next reboot. Also, remove a couple of empty lines at the end of the function. Signed-off-by:
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Javier González authored
Removed unused struct ppa_addr variable. Signed-off-by:
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Javier González authored
Fix comment typo Decrese -> Decrease Signed-off-by:
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Javier González authored
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:
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Javier González authored
Implement helpers to go from ppas to a chunk within a line and an address within a chunk. These helpers will be used on the patches adding trace support in pblk, which will be sent in this window. Signed-off-by:
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Matias Bjørling authored
The read completion path uses the put_line variable to decide whether the reference on a line should be released. The function name used for that is pblk_read_put_rqd_kref, which could lead one to believe that it is the rqd that is releasing the reference, while it is the line reference that is put. Rename and also split the function in two to account for either rqd or single ppa callers and move it to core, such that it later can be used in the write path as well. Signed-off-by:
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Matias Bjørling authored
The I/O size and capacity checks are already done by the block layer. Signed-off-by:
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Matias Bjørling authored
The calculation of pblk->min_write_pgs should only use the optimal write size attribute provided by the drive, it does not correlate to the memory page size of the system, which can be smaller or larger than the LBA size reported. Signed-off-by:
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Matias Bjørling authored
Both NVM_MAX_VLBA and PBLK_MAX_REQ_ADDRS define how many LBAs that are available in a vector command. pblk uses them interchangeably in its implementation. Use NVM_MAX_VLBA as the main one and remove usages of PBLK_MAX_REQ_ADDRS. Also remove the power representation that only has one user, and instead calculate it at runtime. Signed-off-by:
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Matias Bjørling authored
pblk implements two data paths for recovery line state. One for 1.2 and another for 2.0, instead of having pblk implement these, combine them in the core to reduce complexity and make available to other targets. The new interface will adhere to the 2.0 chunk definition, including managing open chunks with an active write pointer. To provide this interface, a 1.2 device recovers the state of the chunks by manually detecting if a chunk is either free/open/close/offline, and if open, scanning the flash pages sequentially to find the next writeable page. This process takes on average ~10 seconds on a device with 64 dies, 1024 blocks and 60us read access time. The process can be parallelized but is left out for maintenance simplicity, as the 1.2 specification is deprecated. For 2.0 devices, the logic is maintained internally in the drive and retrieved through the 2.0 interface. Signed-off-by:
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