- 06 Oct, 2014 8 commits
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Mikulas Patocka authored
When __scan frees the required number of buffer entries that the shrinker requested (nr_to_scan becomes zero) it must return. Before this fix the __scan code exited only the inner loop and continued in the outer loop -- which could result in reduced performance due to extra buffers being freed (e.g. unnecessarily evicted thinp metadata needing to be synchronously re-read into bufio's cache). Also, move dm_bufio_cond_resched to __scan's inner loop, so that iterating the bufio client's lru lists doesn't result in scheduling latency. Reported-by:
Joe Thornber <thornber@redhat.com> Signed-off-by:
Mikulas Patocka <mpatocka@redhat.com> Signed-off-by:
Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.2+
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Joe Thornber authored
The 'last_accessed' member of the dm_buffer structure was only set when the the buffer was created. This led to each buffer being discarded after dm_bufio_max_age time even if it was used recently. In practice this resulted in all thinp metadata being evicted soon after being read -- this is particularly problematic for metadata intensive workloads like multithreaded small random IO. 'last_accessed' is now updated each time the buffer is moved to the head of the LRU list, so the buffer is now properly discarded if it was not used in dm_bufio_max_age time. Signed-off-by:
Joe Thornber <ejt@redhat.com> Signed-off-by:
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Heinz Mauelshagen authored
In case of RAID levels 4, 5 and 6 we have to verify each RAID members' ability to zero data on discards to avoid stripe data corruption -- if discard_zeroes_data is not set for each RAID member discard support must be disabled. But given the uncertainty of whether or not a RAID member properly supports zeroing data on discard we require the user to explicitly allow discard support on RAID levels 4, 5, and 6 by setting a dm-raid module paramter, e.g.: dm-raid.devices_handle_discard_safely=Y Otherwise, discards could cause data corruption on RAID4/5/6. Signed-off-by:
Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by:
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Heinz Mauelshagen authored
Discard support is not enabled for RAID levels 4, 5, and 6 at this time due to concerns about unreliable discard_zeroes_data support on some hardware. Otherwise, discards could cause stripe data corruption (classic example of bad apples spoiling the bunch). Signed-off-by:
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Benjamin Marzinski authored
Until this change, when loading a new DM table, DM core would re-open all of the devices in the DM table. Now, DM core will avoid redundant device opens (and closes when destroying the old table) if the old table already has a device open using the same mode. This is achieved by managing reference counts on the table_devices that DM core now stores in the mapped_device structure (rather than in the dm_table structure). So a mapped_device's active and inactive dm_tables' dm_dev lists now just point to the dm_devs stored in the mapped_device's table_devices list. This improvement in DM core's device reference counting has the side-effect of fixing a long-standing limitation of the multipath target: a DM multipath table couldn't include any paths that were unusable (failed). For example: if all paths have failed and you add a new, working, path to the table; you can't use it since the table load would fail due to it still containing failed paths. Now a re-load of a multipath table can include failed devices and when those devices become active again they can be used instantly. The device list code in dm.c isn't a straight copy/paste from the code in dm-table.c, but it's very close (aside from some variable renames). One subtle difference is that find_table_device for the tables_devices list will only match devices with the same name and mode. This is because we don't want to upgrade a device's mode in the active table when an inactive table is loaded. Access to the mapped_device structure's tables_devices list requires a mutex (tables_devices_lock), so that tables cannot be created and destroyed concurrently. Signed-off-by:
Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by:
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Benjamin Marzinski authored
'queue_io' is set so that IO is queued while paths are being initialized. Clear queue_io in __choose_pgpath if there are no valid paths, since there are obviously no paths that can be initialized. Otherwise IOs to the device will back up. Signed-off-by:
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Junichi Nomura authored
Since DM core uses bio_clone_fast() for both bio-based and request-based DM devices there is no need for DM's bioset to have a bvec mempool. With this patch, on arch with 4KB page for example, memory usage will be reduced by 64KB for each bio-based DM device and 1MB for each request-based DM device. For example, when you create 10,000 bio-based DM devices and 1,000 request-based DM devices, memory usage of biovec under no load is: # grep biovec /proc/slabinfo biovec-256 418068 418068 4096 ... biovec-128 0 0 2048 ... biovec-64 0 0 1024 ... biovec-16 0 0 256 ... With this patch series applied, the usage becomes: # grep biovec /proc/slabinfo biovec-256 116 116 4096 ... biovec-128 0 0 2048 ... biovec-64 0 0 1024 ... biovec-16 0 0 256 ... So 4096 * (418068 - 116) = 1.6GB of memory is saved in this example. Signed-off-by:
Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by:
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Junichi Nomura authored
alloc_tio() uses bio_alloc_bioset() to allocate a clone-bio for a bio. alloc_tio() takes the number of bvecs to allocate for the clone-bio. However, with v3.14's immutable biovec changes DM now uses __bio_clone_fast() and no longer needs to allocate bvecs. In practice, the 'nr_iovecs' passed to alloc_tio() is always effectively 0. __clone_and_map_simple_bio() looked like it was passing non-zero nr_iovecs, but its value was always within the range of inline bvecs and no allocation actually happened. If allocation happened, the BUG_ON() in __bio_clone_fast() would've triggered. Remove the nr_iovecs parameter from alloc_tio() to prevent possible future bio_alloc_bioset() mis-use of a new bioset interface that will no longer allow bvecs to be allocated. Also fix extra whitespace before the __bio_clone_fast() call in __clone_and_map_simple_bio(). Signed-off-by:
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- 03 Oct, 2014 2 commits
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Junichi Nomura authored
Users of bio_clone_fast() do not want bios with their own bvecs. Allocating a bvec mempool as part of the bioset intended for such users is a waste of memory. bioset_create_nobvec() creates a bioset that doesn't have the bvec mempool. Signed-off-by:
Jens Axboe <axboe@fb.com>
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Junichi Nomura authored
Request cloning clones bios in the request to track the completion of each bio. For that purpose, we can use bio_clone_fast() instead of bio_clone() to avoid unnecessary allocation and copy of bvecs. This patch reduces memory footprint of request-based device-mapper (about 1-4KB for each request) and is a preparation for further reduction of memory usage by removing unused bvec mempool. Signed-off-by:
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- 01 Oct, 2014 1 commit
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Hannes Reinecke authored
The rq_complete tracepoint was never issued for empty requests, causing the resulting blktrace information to never show any completion for those request. Signed-off-by:
Hannes Reinecke <hare@suse.de> Acked-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
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- 30 Sep, 2014 1 commit
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Martin K. Petersen authored
A set of flags introduced in the block layer enable better control over how protection information is handled. These flags are useful for both error injection and data recovery purposes. Checking can be enabled and disabled for controller and disk, and the guard tag format is now a per-I/O property. Update sd_protect_op to communicate the relevant information to the low-level device driver via a set of flags in scsi_cmnd. Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by:
Sagi Grimberg <sagig@mellanox.com> Acked-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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- 27 Sep, 2014 14 commits
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Rasmus Villemoes authored
The kernel used to contain two functions for length-delimited, case-insensitive string comparison, strnicmp with correct semantics and a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp was renamed to strncasecmp, and strnicmp made into a wrapper for the new strncasecmp to avoid breaking existing users. To allow the compat wrapper strnicmp to be removed at some point in the future, and to avoid the extra indirection cost, do s/strnicmp/strncasecmp/g. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by:
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Martin K. Petersen authored
The T10 Protection Information format is also used by some devices that do not go through the SCSI layer (virtual block devices, NVMe). Relocate the relevant functions to a block layer library that can be used without involving SCSI. Signed-off-by:
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Martin K. Petersen authored
We'd occasionally merge requests with conflicting integrity flags. Introduce a merge helper which checks that the requests have compatible integrity payloads. Signed-off-by:
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Martin K. Petersen authored
Make the choice of checksum a per-I/O property by introducing a flag that can be inspected by the SCSI layer. There are several reasons for this: 1. It allows us to switch choice of checksum without unloading and reloading the HBA driver. 2. During error recovery we need to be able to tell the HBA that checksums read from disk should not be verified and converted to IP checksums. 3. For error injection purposes we need to be able to write a bad guard tag to storage. Since the storage device only supports T10 CRC we need to be able to disable IP checksum conversion on the HBA. Signed-off-by: -
Martin K. Petersen authored
Move flags affecting the integrity code out of the bio bi_flags and into the block integrity payload. Signed-off-by:
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Martin K. Petersen authored
So far we have relied on the app tag size to determine whether a disk has been formatted with T10 protection information or not. However, not all target devices provide application tag storage. Add a flag to the block integrity profile that indicates whether the disk has been formatted with protection information. Signed-off-by:
Sagi Grimberg <sagig@dev.mellanox.co.il> Signed-off-by:
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Martin K. Petersen authored
Add a BLK_ prefix to the integrity profile flags. Also rename the flags to be more consistent with the generate/verify terminology in the rest of the integrity code. Signed-off-by:
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Martin K. Petersen authored
Instead of the "operate" parameter we pass in a seed value and a pointer to a function that can be used to process the integrity metadata. The generation function is changed to have a return value to fit into this scheme. Signed-off-by:
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Martin K. Petersen authored
Now that the protection interval has been detached from the sector size we need to be able to handle sizes that are different from 4K and 512. Make the interval calculation generic. Signed-off-by:
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Martin K. Petersen authored
The protection interval is not necessarily tied to the logical block size of a block device. Stop using the terms "sector" and "sectors". Going forward we will use the term "seed" to describe the initial reference tag value for a given I/O. "Interval" will be used to describe the portion of the data buffer that a given piece of protection information is associated with. Signed-off-by:
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Martin K. Petersen authored
bip_buf is not really needed so we can remove it. Signed-off-by:
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Martin K. Petersen authored
None of the filesystems appear interested in using the integrity tagging feature. Potentially because very few storage devices actually permit using the application tag space. Remove the tagging functions. Signed-off-by:
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Martin K. Petersen authored
For commands like REQ_COPY we need a way to pass extra information along with each bio. Like integrity metadata this information must be available at the bottom of the stack so bi_private does not suffice. Rename the existing bi_integrity field to bi_special and make it a union so we can have different bio extensions for each class of command. We previously used bi_integrity != NULL as a way to identify whether a bio had integrity metadata or not. Introduce a REQ_INTEGRITY to be the indicator now that bi_special can contain different things. In addition, bio_integrity(bio) will now return a pointer to the integrity payload (when applicable). Signed-off-by:
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Martin K. Petersen authored
bdev_integrity_enabled() is only used by bio_integrity_enabled(). Combine these two functions. Signed-off-by:
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- 25 Sep, 2014 10 commits
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Ming Lei authored
This patch supports to run one single flush machinery for each blk-mq dispatch queue, so that: - current init_request and exit_request callbacks can cover flush request too, then the buggy copying way of initializing flush request's pdu can be fixed - flushing performance gets improved in case of multi hw-queue In fio sync write test over virtio-blk(4 hw queues, ioengine=sync, iodepth=64, numjobs=4, bs=4K), it is observed that througput gets increased a lot over my test environment: - throughput: +70% in case of virtio-blk over null_blk - throughput: +30% in case of virtio-blk over SSD image The multi virtqueue feature isn't merged to QEMU yet, and patches for the feature can be found in below tree: git://kernel.ubuntu.com/ming/qemu.git v2.1.0-mq.4 And simply passing 'num_queues=4 vectors=5' should be enough to enable multi queue(quad queue) feature for QEMU virtio-blk. Suggested-by:
Ming Lei <ming.lei@canonical.com> Signed-off-by:
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Ming Lei authored
This patch adds 'blk_mq_ctx' parameter to blk_get_flush_queue(), so that this function can find the corresponding blk_flush_queue bound with current mq context since the flush queue will become per hw-queue. For legacy queue, the parameter can be simply 'NULL'. For multiqueue case, the parameter should be set as the context from which the related request is originated. With this context info, the hw queue and related flush queue can be found easily. Signed-off-by:
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Ming Lei authored
Just figuring out flush queue at the entry of kicking off flush machinery and request's completion handler, then pass it through. Reviewed-by:
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Ming Lei authored
Now mission of the two helpers is over, and just call blk_alloc_flush_queue() and blk_free_flush_queue() directly. Signed-off-by:
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Ming Lei authored
This patch introduces 'struct blk_flush_queue' and puts all flush machinery related fields into this structure, so that - flush implementation details aren't exposed to driver - it is easy to convert to per dispatch-queue flush machinery This patch is basically a mechanical replacement. Reviewed-by:
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Ming Lei authored
This patch trys to use local variable to access flush request, so that we can convert to per-queue flush machinery a bit easier. Reviewed-by:
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Ming Lei authored
These fields are always used with the flush request, so initialize them together. Reviewed-by:
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Ming Lei authored
These two temporary functions are introduced for holding flush initialization and de-initialization, so that we can introduce 'flush queue' easier in the following patch. And once 'flush queue' and its allocation/free functions are ready, they will be removed for sake of code readability. Reviewed-by:
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Ming Lei authored
It is reasonable to allocate flush req in blk_mq_init_flush(). Reviewed-by:
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Ming Lei authored
Failure of initializing one hctx isn't handled, so this patch introduces blk_mq_init_hctx() and its pair to handle it explicitly. Also this patch makes code cleaner. Reviewed-by:
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- 22 Sep, 2014 4 commits
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Christoph Hellwig authored
Some ATA drivers need the dma drain size workaround, and thus need to call blk_mq_start_request before the S/G mapping. Signed-off-by:
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Christoph Hellwig authored
Signed-off-by:
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Ming Lei authored
Commit 8cb34819cdd5d(blk-mq: unshared timeout handler) introduces blk-mq's own timeout handler, and removes following line: blk_queue_rq_timed_out(q, blk_mq_rq_timed_out); which then causes blk_add_timer() to bypass adding the timer, since blk-mq no longer has q->rq_timed_out_fn defined. This patch fixes the problem by bypassing the check for blk-mq, so that both request deadlines are still set and the rolling timer updated. Signed-off-by:
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Jens Axboe authored
It's not uncommon for crash dump kernels to be limited to 128MB or something low in that area. This is normally not a problem for devices as we don't use that much memory, but for some shared SCSI setups with huge queue depths, it can potentially fill most of memory with tons of request allocations. blk-mq does scale back when it fails to allocate memory, but it scales back just enough so that blk-mq succeeds. This could still leave the system with not enough memory to make any real progress. Check if we are in a kdump environment and limit the hardware queues and tag depth. Signed-off-by:
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