- 26 Jun, 2017 20 commits
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Javier González authored
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>
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Javier González authored
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:
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Javier González authored
At the moment, in order to get enough read parallelism, we have recycled several lines at the same time. This approach has proven not to work well when reaching capacity, since we end up mixing valid data from all lines, thus not maintaining a sustainable free/recycled line ratio. The new design, relies on a two level workqueue mechanism. In the first level, we read the metadata for a number of lines based on the GC list they reside on (this is governed by the number of valid sectors in each line). In the second level, we recycle a single line at a time. Here, we issue reads in parallel, while a single GC write thread places data in the write buffer. This design allows to (i) only move data from one line at a time, thus maintaining a sane free/recycled ration and (ii) maintain the GC writer busy with recycled data. Signed-off-by:
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Javier González authored
Add lockdep assertions on helper functions. Signed-off-by:
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Javier González authored
Cleanup unnecessary headers and code lines. Signed-off-by:
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Javier González authored
Set a dma area for all I/Os in order to read/write from/to the metadata stored on the per-sector out-of-bound area. Signed-off-by:
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Javier González authored
At the moment, we separate the closed lines on three different list based on their number of valid sectors. GC recycles lines from each list based on capacity. Lines from each list are taken in a FIFO fashion. Since the number of lines is limited (it corresponds to the number of blocks in a LUN, which is somewhere between 1000-2000), we can afford scanning the lists to choose the optimal line to be recycled. This helps specially in lines with a high number of valid sectors. If the number of blocks per LUN increases, we will consider a more efficient policy. Signed-off-by:
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Javier González authored
Decouple bad block discovery from line allocation logic. This allows to return meaningful error codes in case of bad block discovery failure. Signed-off-by:
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Javier González authored
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:
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Javier González authored
If a read request is sequential and its size aligns with a multi-plane page size, use the multi-plane hint to process the I/O in parallel in the controller. Signed-off-by:
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Javier González authored
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:
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Javier González authored
Remove a legacy variable that helped verifying the consistency of the run-time metadata for the free line list. With the new metadata layout, this check is no longer necessary. Signed-off-by:
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Javier González authored
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:
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Javier González authored
Read requests allocate some extra memory to store its per I/O context. Instead of requiring yet another memory pool for other type of requests, generalize this context allocation (and change naming accordingly). Signed-off-by:
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Javier González authored
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:
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Javier González authored
Allow to configure the number of maximum sectors per write command through sysfs. This makes it easier to tune write command sizes for different controller configurations. Signed-off-by:
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Javier González authored
Add a new debug counter to measure cache hits on the read path Signed-off-by:
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Javier González authored
Spare a double calculation on the fast write path. Signed-off-by:
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Javier González authored
If nvme_alloc_request fails, propagate the right error, instead of assuming ENOMEM. Signed-off-by:
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Javier González authored
In case of a failure when submitting a request, convert the ppa_list addresses to the target format so that it can interpret ppas for recovery Signed-off-by:
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- 23 Jun, 2017 2 commits
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Jens Axboe authored
This fixes up two commits that have touched this driver. The command status field is now a blk_status_t, so we can't check for < 0 and we definitely can't assume it's holding -Exxxx error values. All we care about here is whether ->status is zero or not. Check for that, and remove the various attempts at smart error reporting. Just log to dmesg what command failed, and the blk_status_t value. Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Fixes: 2a842aca ("block: introduce new block status code type") Fixes: 3f5e6a35 ("mtip32xx: convert internal command issue to block IO path") Signed-off-by:
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Jens Axboe authored
Pull in the fix for shared tags, as it conflicts with the pending changes in for-4.13/block. We already pulled in v4.12-rc5 to solve other conflicts or get fixes that went into 4.12, so not a lot of changes in this merge. Signed-off-by:
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- 22 Jun, 2017 1 commit
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weiping authored
hwctx's queue_num has been set prior call blk_mq_init_hctx, so no need set it again. Signed-off-by:
weiping <zhangweiping@didichuxing.com> Signed-off-by:
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- 21 Jun, 2017 17 commits
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Bart Van Assche authored
Since blk_mq_quiesce_queue_nowait() can be called from interrupt context, make this safe. Since this function is not in the hot path, uninline it. Fixes: commit f4560ffe ("blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue") Signed-off-by:
Bart Van Assche <bart.vanassche@wdc.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by:
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Bart Van Assche authored
This was detected by the smatch static analyzer. Fixes: commit 2a842aca ("block: introduce new block status code type") Signed-off-by:
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Bart Van Assche authored
Avoid that building with W=1 causes the compiler to complain that a declaration for bounce_bio_set and bounce_bio_split is missing. References: commit a8821f3f ("block: Improvements to bounce-buffer handling") Signed-off-by:
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Bart Van Assche authored
This patch suppresses gcc 7 warnings about falling through in switch statements when building with W=1. From the gcc documentation: The -Wimplicit-fallthrough=3 warning is enabled by -Wextra. See also https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gcc/Warning-Options.html. Signed-off-by:
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Jens Axboe authored
If we have shared tags enabled, then every IO completion will trigger a full loop of every queue belonging to a tag set, and every hardware queue for each of those queues, even if nothing needs to be done. This causes a massive performance regression if you have a lot of shared devices. Instead of doing this huge full scan on every IO, add an atomic counter to the main queue that tracks how many hardware queues have been marked as needing a restart. With that, we can avoid looking for restartable queues, if we don't have to. Max reports that this restores performance. Before this patch, 4K IOPS was limited to 22-23K IOPS. With the patch, we are running at 950-970K IOPS. Fixes: 6d8c6c0f ("blk-mq: Restart a single queue if tag sets are shared") Reported-by:
Max Gurtovoy <maxg@mellanox.com> Tested-by:
Bart Van Assche <bart.vanassche@sandisk.com> Tested-by:
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Dan Carpenter authored
This function is supposed to return blk_status_t error codes now but there was a stray -ENOMEM left behind. Fixes: 4e4cbee9 ("block: switch bios to blk_status_t") Signed-off-by:
Christoph Hellwig <hch@lst.de> Acked-by:
David Sterba <dsterba@suse.com> Signed-off-by:
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Bart Van Assche authored
A queue must be frozen while the mapped state of a hardware queue is changed. Additionally, any change of the mapped state is followed by a call to blk_mq_map_swqueue() (see also blk_mq_init_allocated_queue() and blk_mq_update_nr_hw_queues()). Since blk_mq_map_swqueue() does not map any unmapped hardware queue onto any software queue, no attempt will be made to run an unmapped hardware queue. Hence issue a warning upon attempts to run an unmapped hardware queue. Signed-off-by:
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Bart Van Assche authored
The variable 'disk_type' is never modified so constify it. Signed-off-by:
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Bart Van Assche authored
Document the locking assumptions in functions that modify blk_mq_ctx.rq_list to make it easier for humans to verify this code. Signed-off-by:
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Bart Van Assche authored
Some functions in block/blk-core.c must only be used on blk-sq queues while others are safe to use against any queue type. Document which functions are intended for blk-sq queues and issue a warning if the blk-sq API is misused. This does not only help block driver authors but will also make it easier to remove the blk-sq code once that code is declared obsolete. Signed-off-by:
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Bart Van Assche authored
Instead of documenting the locking assumptions of most block layer functions as a comment, use lockdep_assert_held() to verify locking assumptions at runtime. Signed-off-by:
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Bart Van Assche authored
Add a comment above the queue_lockdep_assert_held() macro that explains the purpose of the q->queue_lock test. Signed-off-by:
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Bart Van Assche authored
Initialization of blk-mq requests is a bit weird: blk_mq_rq_ctx_init() is called after a value has been assigned to .rq_flags and .rq_flags is initialized in __blk_mq_finish_request(). Initialize .rq_flags in blk_mq_rq_ctx_init() instead of relying on __blk_mq_finish_request(). Moving the initialization of .rq_flags is fine because all changes and tests of .rq_flags occur between blk_get_request() and finishing a request. Signed-off-by:
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Bart Van Assche authored
Since scsi_req_init() works on a struct scsi_request, change the argument type into struct scsi_request *. Signed-off-by:
Hannes Reinecke <hare@suse.com> Reviewed-by:
Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by:
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Bart Van Assche authored
Instead of explicitly calling scsi_req_init() after blk_get_request(), call that function from inside blk_get_request(). Add an .initialize_rq_fn() callback function to the block drivers that need it. Merge the IDE .init_rq_fn() function into .initialize_rq_fn() because it is too small to keep it as a separate function. Keep the scsi_req_init() call in ide_prep_sense() because it follows a blk_rq_init() call. References: commit 82ed4db4 ("block: split scsi_request out of struct request") Signed-off-by:
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Bart Van Assche authored
Several block drivers need to initialize the driver-private request data after having called blk_get_request() and before .prep_rq_fn() is called, e.g. when submitting a REQ_OP_SCSI_* request. Avoid that that initialization code has to be repeated after every blk_get_request() call by adding new callback functions to struct request_queue and to struct blk_mq_ops. Signed-off-by:
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Bart Van Assche authored
Instead of declaring the second argument of blk_*_get_request() as int and passing it to functions that expect an unsigned int, declare that second argument as unsigned int. Also because of consistency, rename that second argument from 'rw' into 'op'. This patch does not change any functionality. Signed-off-by:
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