- 23 Aug, 2017 22 commits
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Christoph Hellwig authored
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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Christoph Hellwig authored
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Christoph Hellwig authored
This helper allows looking up a partion under RCU protection without grabbing a reference to it. Signed-off-by:
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Christoph Hellwig authored
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Christoph Hellwig authored
The block layer always remaps partitions before calling into the ->make_request methods of drivers. Thus the call to get_start_sect in in_chunk_boundary will always return 0 and can be removed. Reviewed-by:
Shaohua Li <shli@fb.com> Signed-off-by:
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Christoph Hellwig authored
We won't have the struct block_device available in the bio soon, so switch to the numerical dev_t instead of the block_device pointer for looking up the check-integrity state. Reviewed-by:
Liu Bo <bo.li.liu@oracle.com> Signed-off-by:
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Bart Van Assche authored
Since MSI support on some motherboards is unreliable, change the default interrupt mode from MSI to MSI-X. This patch avoids that the following message appears sporadially in the kernel logs of my test setup: do_IRQ: 3.193 No irq handler for vector Signed-off-by:
Bart Van Assche <bart.vanassche@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
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Bart Van Assche authored
Avoid that normal request completion and the timeout handler can run concurrently by calling blk_mq_complete_request() instead of blk_mq_end_request() from skd_end_request(). Avoid that the block layer can reuse a request while the firmware is still processing it. Convert skd_softirq_done() to blk-mq. Pass the pointer to skd_softirq_done() to the block layer core through blk_mq_ops.complete instead of by calling blk_queue_softirq_done(). Pass the pointer to skd_timed_out() to the block layer core through blk_mq_ops.timeout instead of by calling blk_queue_timed_out(). The timeout handler has been tested as follows: echo 1 > /sys/block/skd0/io-timeout-fail && (cd /sys/kernel/debug/fail_io_timeout && echo 100 > probability && echo N > task-filter && echo 1 > times) Fixes: commit a74d5b76 ("skd: Switch to block layer timeout mechanism") Reported-by: -
Bart Van Assche authored
This patch does not change any functionality but makes the skd driver code more similar to that of other blk-mq kernel drivers. Signed-off-by:
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Bart Van Assche authored
This patch removes one debug statement but otherwise does not change any functionality. Signed-off-by:
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Bart Van Assche authored
The timeout handler set by blk_queue_rq_timed_out() is only used in single queue mode. Calling this function for blk-mq drivers is wrong. Hence issue a warning if this function is called by a blk-mq driver. Signed-off-by:
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Shaohua Li authored
Sometime disk could have tracks broken and data there is inaccessable, but data in other parts can be accessed in normal way. MD RAID supports such disks. But we don't have a good way to test it, because we can't control which part of a physical disk is bad. For a virtual disk, this can be easily controlled. This patch adds a new 'badblock' attribute. Configure it in this way: echo "+1-100" > xxx/badblock, this will make sector [1-100] as bad blocks. echo "-20-30" > xxx/badblock, this will make sector [20-30] good If badblocks are accessed, the nullb disk will return IO error. Other parts of the disk can accessed in normal way. Signed-off-by:
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Shaohua Li authored
Software must flush disk cache to guarantee data safety. To check if software correctly does disk cache flush, we must know the behavior of disk. But physical disk behavior is uncontrollable. Even software doesn't do the flush, the disk probably does the flush. This patch tries to emulate a cache in the test disk. All write will go to a cache first, when the cache is full, we then flush some data to disk storage. A flush request will flush all data of the cache to disk storage. A FUA write will write to memory store directly and revalidate data in cache. If there is a power failure (by writing to power attribute, 'echo 0 > disk_name/power'), we discard all data in the cache, but preserve the data in disk storage. Later we can power on the disk again as usual (write 1 to 'power' attribute), then we can check data integrity and very if software does everything correctly. A new attribute 'cache_size' (in MB) is added to configure cache size. Based on original patch from Kyungchan Koh Signed-off-by:
Kyungchan Koh <kkc6196@fb.com> Signed-off-by:
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Shaohua Li authored
In test, we usually expect controllable disk speed. For example, in a raid array, we'd like some disks are fast and some are slow. MD RAID actually has a feature for this. To test the feature, we'd like to make the disk run in specific speed. block throttling probably can be used for this purpose, but it requires cgroup setup. Here we just implement a simple throttling mechanism in the driver. There is slight fluctuation in the mechanism, but it's good enough for test. To configure the bandwidth cap, user sets the 'mbps' attribute. mbps is MB/s. Based on original patch from Kyungchan Koh Signed-off-by:
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Shaohua Li authored
discard makes sense for memory backed disk. And also it's useful to test if upper layer supports dicard correctly. User configures 'discard' attribute to enable/disable dicard support. Based on original patch from Kyungchan Koh Signed-off-by:
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Shaohua Li authored
This adds memory backed store in nullb. User configure 'memory_backed' attribute for this. By default, nullb disk doesn't use memory backed store. Based on original patch from Kyungchan Koh Signed-off-by:
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Shaohua Li authored
We now dynamically create disks. Managing the disk index with ida to avoid bump up the index too much. Signed-off-by:
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Shaohua Li authored
The device created in nullb configfs interface isn't power on by default. After user configures the device, user can do 'echo 1 > xxx/nullb/device_name/power' to power on the device, which will create a disk. the xxx/nullb/device_name/index is the disk index, so if the index is 2, the new created disk should be named as /dev/nullb2. Note, the 'index' is only valid after disk is power on. 'echo 0 > xxx/nullb/device_name/power' will remove the disk. Note, this doesn't remove the device. To remove the device, user should do 'rmdir xxx/nullb/device_name'. Removing the device will remove the disk too. Signed-off-by:
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Shaohua Li authored
Add configfs interface for nullb. configfs interface is more flexible and easy to configure in a per-disk basis. Configuration is something like this: mount -t configfs none /mnt Checking which features the driver supports: cat /mnt/nullb/features The 'features' attribute is for future extension. We probably will add new features into the driver, userspace can check this attribute to find the supported features. Create/remove a device: mkdir/rmdir /mnt/nullb/a Then configure the device by setting attributes under /mnt/nullb/a, most of nullb supported module parameters are converted to attributes: size; /* device size in MB */ completion_nsec; /* time in ns to complete a request */ submit_queues; /* number of submission queues */ home_node; /* home node for the device */ queue_mode; /* block interface */ blocksize; /* block size */ irqmode; /* IRQ completion handler */ hw_queue_depth; /* queue depth */ use_lightnvm; /* register as a LightNVM device */ blocking; /* blocking blk-mq device */ use_per_node_hctx; /* use per-node allocation for hardware context */ Note, creating a device doesn't create a disk immediately. Creating a disk is done in two phases: create a device and then power on the device. Next patch will introduce device power on. Based on original patch from Kyungchan Koh Signed-off-by:
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Shaohua Li authored
When we switch to configfs interface, each disk could have different configuration. To prepare for the change, we move most disk setting to a separate data structure. The existing module parameter interface is kept. The 'nr_devices' and 'shared_tags' don't make sense for per-disk setting, so they are remained as global settings. Signed-off-by:
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Dan Carpenter authored
My initial impulse was to check for IS_ERR_OR_NULL() but when I looked at this code a bit more closely, we should only need to check for IS_ERR(). The blk_mq_alloc_tag_set() returns negative error codes and zero on success so we can just do an "if (rc) goto err_out;". It's better to preserve the error code anyhow. The blk_mq_init_queue() returns error pointers on failure, it never returns NULL. We can also remove the "q = NULL;" at the start because that's no longer needed. Fixes: ca33dd92 ("skd: Convert to blk-mq") Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Dan Carpenter authored
Someone got too agressive about removing initializations and accidentally removed the "rc = 0;" which is required. Fixes: c830da8c ("skd: Remove superfluous initializations from skd_isr_completion_posted()") Signed-off-by:
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- 18 Aug, 2017 18 commits
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Bart Van Assche authored
Remove the driver version information because this information is not useful in an upstream kernel driver. Signed-off-by:
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Bart Van Assche authored
Bump the driver version. Remove the build ID because build IDs do not make sense for an upstream kernel driver. Keep the driver version in the module information but do not report it during every load, unload or probe. Signed-off-by:
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Bart Van Assche authored
Only take skdev->lock if necessary. Signed-off-by:
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Bart Van Assche authored
This patch does not change any functionality but makes the code more brief. Signed-off-by:
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Bart Van Assche authored
Every single coherent DMA memory buffer occupies at least one page. Reduce memory usage by switching from coherent buffers to streaming DMA for I/O requests (struct skd_fitmsg_context) and S/G-lists (struct fit_sg_descriptor[]). Signed-off-by:
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Bart Van Assche authored
Since skd_device.in_flight is only used to display the number of in-flight requests in debug messages, remove that member and introduce skd_in_flight(). That last function relies on the block layer to determine the number of in flight requests. Signed-off-by:
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Bart Van Assche authored
Remove the timeout slot variables and rely on the block layer to detect request timeouts. Signed-off-by:
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Bart Van Assche authored
Introduce a tag set and a blk_mq_ops structure. Set .cmd_size such that struct request and struct skd_request_context are allocated through a single allocation. Remove the skd_request_context.req pointer. Make queue starting asynchronous such that this can occur safely from interrupt context. Use locking to protect skdev->skmsg and *skdev->skmsg against concurrent access from concurrent .queue_rq() calls. Introduce the functions skd_init_request() and skd_exit_request() to set up / clean up the per-request S/G-list. Signed-off-by:
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Bart Van Assche authored
Set request_queue.cmd_size, introduce skd_init_rq() and skd_exit_rq() and remove skd_device.skreq_table. Signed-off-by:
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Bart Van Assche authored
Issue a warning if a NULL argument is passed to skd_free_sg_list(). Move this function up to make the blk-mq conversion patch easier to read. Signed-off-by:
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Bart Van Assche authored
This patch does not change any functionality but makes the blk-mq conversion patch easier to read. Signed-off-by:
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Bart Van Assche authored
The only functional change in this patch is that the skd_fitmsg_context in which requests are accumulated is changed from a local variable into a member of struct skd_device. This patch will make the blk-mq conversion easier. Signed-off-by:
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Bart Van Assche authored
Convert the per-device scalar variables that are protected by the queue lock into atomics such that it becomes safe to access these variables without holding the queue lock. Signed-off-by:
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Bart Van Assche authored
Use the request tag when allocating a skd_fitmsg_context or skd_request_context such that the lists used to track free elements can be eliminated. Swap the skd_end_request() and skd_release_req() calls to avoid triggering a use-after-free. Remove skd_fitmsg_context.state and .outstanding because FIT messages are shared among requests and because updating a FIT message after a request has finished whould trigger a use-after-free. Signed-off-by:
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Bart Van Assche authored
The debug code in skd_send_special_fitmsg() assumes that req.n_sg represents the number of S/G descriptors. However, skd_construct() initializes that member variable to zero. Set req.n_sg to one such that the debugging code in skd_send_special_fitmsg() works as expected. Signed-off-by:
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Bart Van Assche authored
Removing the SG IO code also removed the code that sets SKD_REQ_STATE_ABORTED. Hence also remove the code that checks for this state. Signed-off-by:
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Bart Van Assche authored
The skd SG IO support duplicates the functionality of the bsg driver. Hence remove it. Signed-off-by:
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Bart Van Assche authored
This will make it easier to convert this driver to the blk-mq approach. This patch also reduces interrupt latency by moving skd_request_fn() calls out of the skd_isr() interrupt. Signed-off-by:
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