kernel/linux.git/drivers/md/dm.c, branch v5.6.17

Revert "dm: always call blk_queue_split() in dm_process_bio()"

2020-04-08T07:11:08+00:00

commit 120c9257f5f19e5d1e87efcbb5531b7cd81b7d74 upstream. This reverts commit effd58c95f277744f75d6e08819ac859dbcbd351. blk_queue_split() is causing excessive IO splitting -- because blk_max_size_offset() depends on 'chunk_sectors' limit being set and if it isn't (as is the case for DM targets!) it falls back to splitting on a 'max_sectors' boundary regardless of offset. "Fix" this by reverting back to _not_ using blk_queue_split() in dm_process_bio() for normal IO (reads and writes). Long-term fix is still TBD but it should focus on training blk_max_size_offset() to call into a DM provided hook (to call DM's max_io_len()). Test results from simple misaligned IO test on 4-way dm-striped device with chunksize of 128K and stripesize of 512K: xfs_io -d -c 'pread -b 2m 224s 4072s' /dev/mapper/stripe_dev before this revert: 253,0 21 1 0.000000000 2206 Q R 224 + 4072 [xfs_io] 253,0 21 2 0.000008267 2206 X R 224 / 480 [xfs_io] 253,0 21 3 0.000010530 2206 X R 224 / 256 [xfs_io] 253,0 21 4 0.000027022 2206 X R 480 / 736 [xfs_io] 253,0 21 5 0.000028751 2206 X R 480 / 512 [xfs_io] 253,0 21 6 0.000033323 2206 X R 736 / 992 [xfs_io] 253,0 21 7 0.000035130 2206 X R 736 / 768 [xfs_io] 253,0 21 8 0.000039146 2206 X R 992 / 1248 [xfs_io] 253,0 21 9 0.000040734 2206 X R 992 / 1024 [xfs_io] 253,0 21 10 0.000044694 2206 X R 1248 / 1504 [xfs_io] 253,0 21 11 0.000046422 2206 X R 1248 / 1280 [xfs_io] 253,0 21 12 0.000050376 2206 X R 1504 / 1760 [xfs_io] 253,0 21 13 0.000051974 2206 X R 1504 / 1536 [xfs_io] 253,0 21 14 0.000055881 2206 X R 1760 / 2016 [xfs_io] 253,0 21 15 0.000057462 2206 X R 1760 / 1792 [xfs_io] 253,0 21 16 0.000060999 2206 X R 2016 / 2272 [xfs_io] 253,0 21 17 0.000062489 2206 X R 2016 / 2048 [xfs_io] 253,0 21 18 0.000066133 2206 X R 2272 / 2528 [xfs_io] 253,0 21 19 0.000067507 2206 X R 2272 / 2304 [xfs_io] 253,0 21 20 0.000071136 2206 X R 2528 / 2784 [xfs_io] 253,0 21 21 0.000072764 2206 X R 2528 / 2560 [xfs_io] 253,0 21 22 0.000076185 2206 X R 2784 / 3040 [xfs_io] 253,0 21 23 0.000077486 2206 X R 2784 / 2816 [xfs_io] 253,0 21 24 0.000080885 2206 X R 3040 / 3296 [xfs_io] 253,0 21 25 0.000082316 2206 X R 3040 / 3072 [xfs_io] 253,0 21 26 0.000085788 2206 X R 3296 / 3552 [xfs_io] 253,0 21 27 0.000087096 2206 X R 3296 / 3328 [xfs_io] 253,0 21 28 0.000093469 2206 X R 3552 / 3808 [xfs_io] 253,0 21 29 0.000095186 2206 X R 3552 / 3584 [xfs_io] 253,0 21 30 0.000099228 2206 X R 3808 / 4064 [xfs_io] 253,0 21 31 0.000101062 2206 X R 3808 / 3840 [xfs_io] 253,0 21 32 0.000104956 2206 X R 4064 / 4096 [xfs_io] 253,0 21 33 0.001138823 0 C R 4096 + 200 [0] after this revert: 253,0 18 1 0.000000000 4430 Q R 224 + 3896 [xfs_io] 253,0 18 2 0.000018359 4430 X R 224 / 256 [xfs_io] 253,0 18 3 0.000028898 4430 X R 256 / 512 [xfs_io] 253,0 18 4 0.000033535 4430 X R 512 / 768 [xfs_io] 253,0 18 5 0.000065684 4430 X R 768 / 1024 [xfs_io] 253,0 18 6 0.000091695 4430 X R 1024 / 1280 [xfs_io] 253,0 18 7 0.000098494 4430 X R 1280 / 1536 [xfs_io] 253,0 18 8 0.000114069 4430 X R 1536 / 1792 [xfs_io] 253,0 18 9 0.000129483 4430 X R 1792 / 2048 [xfs_io] 253,0 18 10 0.000136759 4430 X R 2048 / 2304 [xfs_io] 253,0 18 11 0.000152412 4430 X R 2304 / 2560 [xfs_io] 253,0 18 12 0.000160758 4430 X R 2560 / 2816 [xfs_io] 253,0 18 13 0.000183385 4430 X R 2816 / 3072 [xfs_io] 253,0 18 14 0.000190797 4430 X R 3072 / 3328 [xfs_io] 253,0 18 15 0.000197667 4430 X R 3328 / 3584 [xfs_io] 253,0 18 16 0.000218751 4430 X R 3584 / 3840 [xfs_io] 253,0 18 17 0.000226005 4430 X R 3840 / 4096 [xfs_io] 253,0 18 18 0.000250404 4430 Q R 4120 + 176 [xfs_io] 253,0 18 19 0.000847708 0 C R 4096 + 24 [0] 253,0 18 20 0.000855783 0 C R 4120 + 176 [0] Fixes: effd58c95f27774 ("dm: always call blk_queue_split() in dm_process_bio()") Cc: stable@vger.kernel.org Reported-by: Andreas Gruenbacher Tested-by: Barry Marson Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm: fix congested_fn for request-based device

2020-03-03T16:10:20+00:00

We neither assign congested_fn for requested-based blk-mq device nor implement it correctly. So fix both. Also, remove incorrect comment from dm_init_normal_md_queue and rename it to dm_init_congested_fn. Fixes: 4aa9c692e052 ("bdi: separate out congested state into a separate struct") Cc: stable@vger.kernel.org Signed-off-by: Hou Tao Signed-off-by: Mike Snitzer

dm: report suspended device during destroy

2020-02-27T21:40:58+00:00

The function dm_suspended returns true if the target is suspended. However, when the target is being suspended during unload, it returns false. An example where this is a problem: the test "!dm_suspended(wc->ti)" in writecache_writeback is not sufficient, because dm_suspended returns zero while writecache_suspend is in progress. As is, without an enhanced dm_suspended, simply switching from flush_workqueue to drain_workqueue still emits warnings: workqueue writecache-writeback: drain_workqueue() isn't complete after 10 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 100 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 200 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 300 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 400 tries writecache_suspend calls flush_workqueue(wc->writeback_wq) - this function flushes the current work. However, the workqueue may re-queue itself and flush_workqueue doesn't wait for re-queued works to finish. Because of this - the function writecache_writeback continues execution after the device was suspended and then concurrently with writecache_dtr, causing a crash in writecache_writeback. We must use drain_workqueue - that waits until the work and all re-queued works finish. As a prereq for switching to drain_workqueue, this commit fixes dm_suspended to return true after the presuspend hook and before the postsuspend hook - just like during a normal suspend. It allows simplifying the dm-integrity and dm-writecache targets so that they don't have to maintain suspended flags on their own. With this change use of drain_workqueue() can be used effectively. This change was tested with the lvm2 testsuite and cryptsetup testsuite and the are no regressions. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Reported-by: Corey Marthaler Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm: fix potential for q->make_request_fn NULL pointer

2020-01-27T19:52:36+00:00

Move blk_queue_make_request() to dm.c:alloc_dev() so that q->make_request_fn is never NULL during the lifetime of a DM device (even one that is created without a DM table). Otherwise generic_make_request() will crash simply by doing: dmsetup create -n test mount /dev/dm-N /mnt While at it, move ->congested_data initialization out of dm.c:alloc_dev() and into the bio-based specific init method. Reported-by: Stefan Bader BugLink: https://bugs.launchpad.net/bugs/1860231 Fixes: ff36ab34583a ("dm: remove request-based logic from make_request_fn wrapper") Depends-on: c12c9a3c3860c ("dm: various cleanups to md->queue initialization code") Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer

block: rework zone reporting

2019-11-13T02:12:07+00:00

Avoid the need to allocate a potentially large array of struct blk_zone in the block layer by switching the ->report_zones method interface to a callback model. Now the caller simply supplies a callback that is executed on each reported zone, and private data for it. Signed-off-by: Christoph Hellwig Signed-off-by: Shin'ichiro Kawasaki Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Mike Snitzer Signed-off-by: Jens Axboe

block: Remove partition support for zoned block devices

2019-11-13T02:11:57+00:00

No known partitioning tool supports zoned block devices, especially the host managed flavor with strong sequential write constraints. Furthermore, there are also no known user nor use cases for partitioned zoned block devices. This patch removes partition device creation for zoned block devices, which allows simplifying the processing of zone commands for zoned block devices. A warning is added if a partition table is found on the device. For report zones operations no zone sector information remapping is necessary anymore, simplifying the code. Of note is that remapping of zone reports for DM targets is still necessary as done by dm_remap_zone_report(). Similarly, remaping of a zone reset bio is not necessary anymore. Testing for the applicability of the zone reset all request also becomes simpler and only needs to check that the number of sectors of the requested zone range is equal to the disk capacity. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Damien Le Moal Signed-off-by: Jens Axboe

block: Simplify report zones execution

2019-11-13T02:11:56+00:00

All kernel users of blkdev_report_zones() as well as applications use through ioctl(BLKZONEREPORT) expect to potentially get less zone descriptors than requested. As such, the use of the internal report zones command execution loop implemented by blk_report_zones() is not necessary and can even be harmful to performance by causing the execution of inefficient small zones report command to service the reminder of a requested zone array. This patch removes blk_report_zones(), simplifying the code. Also remove a now incorrect comment in dm_blk_report_zones(). Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Javier Gonzalez Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

dm: add zone open, close and finish support

2019-11-07T13:36:08+00:00

Implement REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH support to allow explicit control of zone states. Contains contributions from Matias Bjorling, Hans Holmberg and Damien Le Moal. Acked-by: Mike Snitzer Reviewed-by: Christoph Hellwig Signed-off-by: Ajay Joshi Signed-off-by: Matias Bjorling Signed-off-by: Hans Holmberg Signed-off-by: Damien Le Moal Signed-off-by: Jens Axboe

dm: make dm_table_find_target return NULL

2019-08-23T14:13:12+00:00

Currently, if we pass too high sector number to dm_table_find_target, it returns zeroed dm_target structure and callers test if the structure is zeroed with the macro dm_target_is_valid. However, returning NULL is common practice to indicate errors. This patch refactors the dm code, so that dm_table_find_target returns NULL and its callers test the returned value for NULL. The macro dm_target_is_valid is deleted. In alloc_targets, we no longer allocate an extra zeroed target. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

Merge tag 'libnvdimm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2019-07-18T17:52:08+00:00

Pull libnvdimm updates from Dan Williams: "Primarily just the virtio_pmem driver: - virtio_pmem The new virtio_pmem facility introduces a paravirtualized persistent memory device that allows a guest VM to use DAX mechanisms to access a host-file with host-page-cache. It arranges for MAP_SYNC to be disabled and instead triggers a host fsync() when a 'write-cache flush' command is sent to the virtual disk device. - Miscellaneous small fixups" * tag 'libnvdimm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: virtio_pmem: fix sparse warning xfs: disable map_sync for async flush ext4: disable map_sync for async flush dax: check synchronous mapping is supported dm: enable synchronous dax libnvdimm: add dax_dev sync flag virtio-pmem: Add virtio pmem driver libnvdimm: nd_region flush callback support libnvdimm, namespace: Drop uuid_t implementation detail