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2018-04-10Merge tag 'libnvdimm-for-4.17' of ↵Linus Torvalds1-4/+6
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "This cycle was was not something I ever want to repeat as there were several late changes that have only now just settled. Half of the branch up to commit d2c997c0f145 ("fs, dax: use page->mapping to warn...") have been in -next for several releases. The of_pmem driver and the address range scrub rework were late arrivals, and the dax work was scaled back at the last moment. The of_pmem driver missed a previous merge window due to an oversight. A sense of obligation to rectify that miss is why it is included for 4.17. It has acks from PowerPC folks. Stephen reported a build failure that only occurs when merging it with your latest tree, for now I have fixed that up by disabling modular builds of of_pmem. A test merge with your tree has received a build success report from the 0day robot over 156 configs. An initial version of the ARS rework was submitted before the merge window. It is self contained to libnvdimm, a net code reduction, and passing all unit tests. The filesystem-dax changes are based on the wait_var_event() functionality from tip/sched/core. However, late review feedback showed that those changes regressed truncate performance to a large degree. The branch was rewound to drop the truncate behavior change and now only includes preparation patches and cleanups (with full acks and reviews). The finalization of this dax-dma-vs-trnucate work will need to wait for 4.18. Summary: - A rework of the filesytem-dax implementation provides for detection of unmap operations (truncate / hole punch) colliding with in-progress device-DMA. A fix for these collisions remains a work-in-progress pending resolution of truncate latency and starvation regressions. - The of_pmem driver expands the users of libnvdimm outside of x86 and ACPI to describe an implementation of persistent memory on PowerPC with Open Firmware / Device tree. - Address Range Scrub (ARS) handling is completely rewritten to account for the fact that ARS may run for 100s of seconds and there is no platform defined way to cancel it. ARS will now no longer block namespace initialization. - The NVDIMM Namespace Label implementation is updated to handle label areas as small as 1K, down from 128K. - Miscellaneous cleanups and updates to unit test infrastructure" * tag 'libnvdimm-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (39 commits) libnvdimm, of_pmem: workaround OF_NUMA=n build error nfit, address-range-scrub: add module option to skip initial ars nfit, address-range-scrub: rework and simplify ARS state machine nfit, address-range-scrub: determine one platform max_ars value powerpc/powernv: Create platform devs for nvdimm buses doc/devicetree: Persistent memory region bindings libnvdimm: Add device-tree based driver libnvdimm: Add of_node to region and bus descriptors libnvdimm, region: quiet region probe libnvdimm, namespace: use a safe lookup for dimm device name libnvdimm, dimm: fix dpa reservation vs uninitialized label area libnvdimm, testing: update the default smart ctrl_temperature libnvdimm, testing: Add emulation for smart injection commands nfit, address-range-scrub: introduce nfit_spa->ars_state libnvdimm: add an api to cast a 'struct nd_region' to its 'struct device' nfit, address-range-scrub: fix scrub in-progress reporting dax, dm: allow device-mapper to operate without dax support dax: introduce CONFIG_DAX_DRIVER fs, dax: use page->mapping to warn if truncate collides with a busy page ext2, dax: introduce ext2_dax_aops ...
2018-04-09Merge branch 'for-4.17/dax' into libnvdimm-for-nextDan Williams1-4/+6
2018-04-06Merge tag 'for-4.17/dm-changes' of ↵Linus Torvalds1-65/+80
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - DM core passthrough ioctl fix to retain reference to DM table, and that table's block devices, while issuing the ioctl to one of those block devices. - DM core passthrough ioctl fix to _not_ override the fmode_t used to issue the ioctl. Overriding by using the fmode_t that the block device was originally open with during DM table load is a liability. - Add DM core support for secure erase forwarding and update the DM linear and DM striped targets to support them. - A DM core 4.16 stable fix to allow abnormal IO (e.g. discard, write same, write zeroes) for targets that make use of the non-splitting IO variant (as is done for multipath or thinp when layered directly on NVMe). - Allow DM targets to return a payload in response to a DM message that they are sent. This is useful for DM targets that would like to provide statistics data in response to DM messages. - Update DM bufio to support non-power-of-2 block sizes. Numerous other related changes prepare the DM bufio code for this support. - Fix DM crypt to use a bounded amount of memory across the entire system. This is to avoid OOM that can otherwise occur in response to certain pathological IO workloads (e.g. discarding a large DM crypt device). - Add a 'check_at_most_once' feature to the DM verity target to allow verity to be used on mobile devices that have very limited resources. - Fix the DM integrity target to fail early if a keyed algorithm (e.g. HMAC) is to be used but the key isn't set. - Add non-power-of-2 support to the DM unstripe target. - Eliminate the use of a Variable Length Array in the DM stripe target. - Update the DM log-writes target to record metadata (REQ_META flag). - DM raid fixes for its nosync status and some variable range issues. * tag 'for-4.17/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (28 commits) dm: remove fmode_t argument from .prepare_ioctl hook dm: hold DM table for duration of ioctl rather than use blkdev_get dm raid: fix parse_raid_params() variable range issue dm verity: make verity_for_io_block static dm verity: add 'check_at_most_once' option to only validate hashes once dm bufio: don't embed a bio in the dm_buffer structure dm bufio: support non-power-of-two block sizes dm bufio: use slab cache for dm_buffer structure allocations dm bufio: reorder fields in dm_buffer structure dm bufio: relax alignment constraint on slab cache dm bufio: remove code that merges slab caches dm bufio: get rid of slab cache name allocations dm bufio: move dm-bufio.h to include/linux/ dm bufio: delete outdated comment dm: add support for secure erase forwarding dm: backfill abnormal IO support to non-splitting IO submission dm raid: fix nosync status dm mpath: use DM_MAPIO_SUBMITTED instead of magic number 0 in process_queued_bios() dm stripe: get rid of a Variable Length Array (VLA) dm log writes: record metadata flag for better flags record ...
2018-04-05Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+1
Pull block layer updates from Jens Axboe: "It's a pretty quiet round this time, which is nice. This contains: - series from Bart, cleaning up the way we set/test/clear atomic queue flags. - series from Bart, fixing races between gendisk and queue registration and removal. - set of bcache fixes and improvements from various folks, by way of Michael Lyle. - set of lightnvm updates from Matias, most of it being the 1.2 to 2.0 transition. - removal of unused DIO flags from Nikolay. - blk-mq/sbitmap memory ordering fixes from Omar. - divide-by-zero fix for BFQ from Paolo. - minor documentation patches from Randy. - timeout fix from Tejun. - Alpha "can't write a char atomically" fix from Mikulas. - set of NVMe fixes by way of Keith. - bsg and bsg-lib improvements from Christoph. - a few sed-opal fixes from Jonas. - cdrom check-disk-change deadlock fix from Maurizio. - various little fixes, comment fixes, etc from various folks" * tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits) blk-mq: Directly schedule q->timeout_work when aborting a request blktrace: fix comment in blktrace_api.h lightnvm: remove function name in strings lightnvm: pblk: remove some unnecessary NULL checks lightnvm: pblk: don't recover unwritten lines lightnvm: pblk: implement 2.0 support lightnvm: pblk: implement get log report chunk lightnvm: pblk: rename ppaf* to addrf* lightnvm: pblk: check for supported version lightnvm: implement get log report chunk helpers lightnvm: make address conversions depend on generic device lightnvm: add support for 2.0 address format lightnvm: normalize geometry nomenclature lightnvm: complete geo structure with maxoc* lightnvm: add shorten OCSSD version in geo lightnvm: add minor version to generic geometry lightnvm: simplify geometry structure lightnvm: pblk: refactor init/exit sequences lightnvm: Avoid validation of default op value lightnvm: centralize permission check for lightnvm ioctl ...
2018-04-04dm: remove fmode_t argument from .prepare_ioctl hookMike Snitzer1-11/+7
Use the fmode_t that is passed to dm_blk_ioctl() rather than inconsistently (varies across targets) drop it on the floor by overriding it with the fmode_t stored in 'struct dm_dev'. All the persistent reservation functions weren't using the fmode_t they got back from .prepare_ioctl so remove them. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-04dm: hold DM table for duration of ioctl rather than use blkdev_getMike Snitzer1-53/+44
Commit 519049afead ("dm: use blkdev_get rather than bdgrab when issuing pass-through ioctl") inadvertantly introduced a regression relative to users of device cgroups that issue ioctls (e.g. libvirt). Using blkdev_get() in DM's passthrough ioctl support implicitly introduced a cgroup permissions check that would fail unless care were taken to add all devices in the IO stack to the device cgroup. E.g. rather than just adding the top-level DM multipath device to the cgroup all the underlying devices would need to be allowed. Fix this, to no longer require allowing all underlying devices, by simply holding the live DM table (which includes the table's original blkdev_get() reference on the blockdevice that the ioctl will be issued to) for the duration of the ioctl. Also, bump the DM ioctl version so a user can know that their device cgroup allow workaround is no longer needed. Reported-by: Michal Privoznik <mprivozn@redhat.com> Suggested-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: 519049afead ("dm: use blkdev_get rather than bdgrab when issuing pass-through ioctl") Cc: stable@vger.kernel.org # 4.16 Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-03dm: add support for secure erase forwardingDenis Semakin1-0/+12
Set QUEUE_FLAG_SECERASE in DM device's queue_flags if a DM table's data devices support secure erase. Also, add support for secure erase to both the linear and striped targets. Signed-off-by: Denis Semakin <d.semakin@omprussia.ru> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-03dm: backfill abnormal IO support to non-splitting IO submissionMike Snitzer1-7/+23
Otherwise, these abnormal IOs would be sent to the DM target regardless of whether the target advertised support for them. Factor out __process_abnormal_io() from __split_and_process_non_flush() so that discards, write same, etc may be conditionally processed. Fixes: 978e51ba3 ("dm: optimize bio-based NVMe IO submission") Cc: stable@vger.kernel.org # 4.16 Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-03dax, dm: allow device-mapper to operate without dax supportDan Williams1-4/+6
Change device-mapper's DAX dependency to require the presence of at least one DAX_DRIVER. This allows device-mapper to be built without bringing the DAX core along which is especially wasteful when there are no DAX drivers, like BLK_DEV_PMEM, configured. Cc: Alasdair Kergon <agk@redhat.com> Reported-by: Bart Van Assche <Bart.VanAssche@wdc.com> Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-03-29dm: fix dropped return code from dm_get_bdev_for_ioctlMike Snitzer1-3/+5
dm_get_bdev_for_ioctl()'s return of 0 or 1 must be the result from prepare_ioctl (1 means the ioctl was issued to a partition, 0 means it wasn't). Unfortunately commit 519049afea ("dm: use blkdev_get rather than bdgrab when issuing pass-through ioctl") reused the variable 'r' to store the return from blkdev_get() that follows prepare_ioctl() -- whereby dropping prepare_ioctl()'s result on the floor. This can lead to an ioctl or persistent reservation being issued to a partition going unnoticed, which implies the extra permission check for CAP_SYS_RAWIO is skipped. Fix this by using a different variable to store blkdev_get()'s return. Fixes: 519049afea ("dm: use blkdev_get rather than bdgrab when issuing pass-through ioctl") Reported-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-03-06dm: use blkdev_get rather than bdgrab when issuing pass-through ioctlMike Snitzer1-15/+20
Otherwise an underlying device's teardown (e.g. SCSI) may race with the DM ioctl or persistent reservation and result in dereferencing driver memory that gets freed when the underlying device's final blkdev_put() occurs. bdgrab() only increases the refcount for the block_device's inode to ensure the block_device struct itself will not be freed, but does not guarantee the block_device will remain associated with the gendisk or its storage. Cc: stable@vger.kernel.org # 4.8+ Reported-by: David Jeffery <djeffery@redhat.com> Suggested-by: David Jeffery <djeffery@redhat.com> Reviewed-by: Ben Marzinski <bmarzins@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-02-28block: Add 'lock' as third argument to blk_alloc_queue_node()Bart Van Assche1-1/+1
This patch does not change any functionality. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-16dm: correctly handle chained bios in dec_pending()NeilBrown1-1/+2
dec_pending() is given an error status (possibly 0) to be recorded against a bio. It can be called several times on the one 'struct dm_io', and it is careful to only assign a non-zero error to io->status. However when it then assigned io->status to bio->bi_status, it is not careful and could overwrite a genuine error status with 0. This can happen when chained bios are in use. If a bio is chained beneath the bio that this dm_io is handling, the child bio might complete and set bio->bi_status before the dm_io completes. This has been possible since chained bios were introduced in 3.14, and has become a lot easier to trigger with commit 18a25da84354 ("dm: ensure bio submission follows a depth-first tree walk") as that commit caused dm to start using chained bios itself. A particular failure mode is that if a bio spans an 'error' target and a working target, the 'error' fragment will complete instantly and set the ->bi_status, and the other fragment will normally complete a little later, and will clear ->bi_status. The fix is simply to only assign io_error to bio->bi_status when io_error is not zero. Reported-and-tested-by: Milan Broz <gmazyland@gmail.com> Cc: stable@vger.kernel.org (v3.14+) Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-31Merge tag 'for-4.16/dm-changes' of ↵Linus Torvalds1-269/+390
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - DM core fixes to ensure that bio submission follows a depth-first tree walk; this is critical to allow forward progress without the need to use the bioset's BIOSET_NEED_RESCUER. - Remove DM core's BIOSET_NEED_RESCUER based dm_offload infrastructure. - DM core cleanups and improvements to make bio-based DM more efficient (e.g. reduced memory footprint as well leveraging per-bio-data more). - Introduce new bio-based mode (DM_TYPE_NVME_BIO_BASED) that leverages the more direct IO submission path in the block layer; this mode is used by DM multipath and also optimizes targets like DM thin-pool that stack directly on NVMe data device. - DM multipath improvements to factor out legacy SCSI-only (e.g. scsi_dh) code paths to allow for more optimized support for NVMe multipath. - A fix for DM multipath path selectors (service-time and queue-length) to select paths in a more balanced way; largely academic but doesn't hurt. - Numerous DM raid target fixes and improvements. - Add a new DM "unstriped" target that enables Intel to workaround firmware limitations in some NVMe drives that are striped internally (this target also works when stacked above the DM "striped" target). - Various Documentation fixes and improvements. - Misc cleanups and fixes across various DM infrastructure and targets (e.g. bufio, flakey, log-writes, snapshot). * tag 'for-4.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (69 commits) dm cache: Documentation: update default migration_throttling value dm mpath selector: more evenly distribute ties dm unstripe: fix target length versus number of stripes size check dm thin: fix trailing semicolon in __remap_and_issue_shared_cell dm table: fix NVMe bio-based dm_table_determine_type() validation dm: various cleanups to md->queue initialization code dm mpath: delay the retry of a request if the target responded as busy dm mpath: return DM_MAPIO_DELAY_REQUEUE if QUEUE_IO or PG_INIT_REQUIRED dm mpath: return DM_MAPIO_REQUEUE on blk-mq rq allocation failure dm log writes: fix max length used for kstrndup dm: backfill missing calls to mutex_destroy() dm snapshot: use mutex instead of rw_semaphore dm flakey: check for null arg_name in parse_features() dm thin: extend thinpool status format string with omitted fields dm thin: fixes in thin-provisioning.txt dm thin: document representation of <highest mapped sector> when there is none dm thin: fix documentation relative to low water mark threshold dm cache: be consistent in specifying sectors and SI units in cache.txt dm cache: delete obsoleted paragraph in cache.txt dm cache: fix grammar in cache-policies.txt ...
2018-01-29dm: various cleanups to md->queue initialization codeMike Snitzer1-18/+12
Also, add dm_sysfs_init() error handling to dm_create(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17dm: backfill missing calls to mutex_destroy()Mike Snitzer1-0/+4
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-15dm: fix incomplete request_queue initializationMike Snitzer1-1/+10
DM is no longer prone to having its request_queue be improperly initialized. Summary of changes: - defer DM's blk_register_queue() from add_disk()-time until dm_setup_md_queue() by using add_disk_no_queue_reg() in alloc_dev(). - dm_setup_md_queue() is updated to fully initialize DM's request_queue (_after_ all table loads have occurred and the request_queue's type, features and limits are known). A very welcome side-effect of these changes is DM no longer needs to: 1) backfill the "mq" sysfs entry (because historically DM didn't initialize the request_queue to use blk-mq until _after_ blk_register_queue() was called via add_disk()). 2) call elv_register_queue() to get .request_fn request-based DM device's "iosched" exposed in syfs. In addition, blk-mq debugfs support is now made available because request-based DM's blk-mq request_queue is now properly initialized before dm_setup_md_queue() calls blk_register_queue(). These changes also stave off the need to introduce new DM-specific workarounds in block core, e.g. this proposal: https://patchwork.kernel.org/patch/10067961/ In the end DM devices should be less unicorn in nature (relative to initialization and availability of block core infrastructure provided by the request_queue). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Tested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-06dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZEMing Lei1-1/+9
For BIO based DM, some targets aren't ready for dealing with bigger incoming bio than 1Mbyte, such as crypt target. Cc: Mike Snitzer <snitzer@redhat.com> Cc:dm-devel@redhat.com Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-12-20dm: optimize bio-based NVMe IO submissionMike Snitzer1-34/+120
Upper level bio-based drivers that stack immediately ontop of NVMe can leverage direct_make_request(). In addition DM's NVMe bio-based will initially only ever have one NVMe device that it submits IO to at a time. There is no splitting needed. Enhance DM core so that DM_TYPE_NVME_BIO_BASED's IO submission takes advantage of both of these characteristics. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-20dm: introduce DM_TYPE_NVME_BIO_BASEDMike Snitzer1-0/+2
If dm_table_determine_type() establishes DM_TYPE_NVME_BIO_BASED then all devices in the DM table do not support partial completions. Also, the table has a single immutable target that doesn't require DM core to split bios. This will enable adding NVMe optimizations to bio-based DM. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-17dm: simplify start of block stats accounting for bio-basedMike Snitzer1-8/+3
No apparent need to generic_start_io_acct() until before the IO is ready for submission. start_io_acct() is the proper place to do this accounting -- it is also where DM accounts for pending IO and, if enabled, starts dm-stats accounting. Replace start_io_acct()'s part_round_stats() with generic_start_io_acct(). This eliminates needing to take part_stat_lock() multiple times when starting an IO on bio-based devices. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-16dm: remove redundant mapped_device member from clone_info structureMike Snitzer1-6/+4
'struct dm_io' already has the same pointer. So update all accesses from ci->md to ci->io->md. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-16dm: remove now unused bio-based io_pool and _io_cacheMike Snitzer1-28/+2
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-16dm: improve performance by moving dm_io structure to per-bio-dataMike Snitzer1-40/+129
Eliminates need for a separate mempool to allocate 'struct dm_io' objects from. As such, it saves an extra mempool allocation for each original bio that DM core is issued. This complicates the per-bio-data accessor functions by needing to conditonally add extra padding to get to a target's per-bio-data. But in the end this provides a decent performance improvement for all bio-based DM devices. On an NVMe-loop based testbed to a ramdisk (~3100 MB/s): bio-based DM linear performance improved by 2% (went from 2665 to 2777 MB/s). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-16dm: rename 'bio' member of dm_io structure to 'orig_bio'Mike Snitzer1-14/+14
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-16dm: remove stale comment blocksMike Snitzer1-12/+0
These CRUD comments have worn out their welcome. The code is what it is, over time it'll hopefully get better. But these comments serve no purpose whatsoever. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-13dm: set QUEUE_FLAG_DAX accordingly in dm_table_set_restrictions()Mike Snitzer1-3/+0
Rather than having DAX support be unique by setting it based on table type in dm_setup_md_queue(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-13dm: fix __send_changing_extent_only() to send first bio and chain remainderMike Snitzer1-36/+30
__send_changing_extent_only() must follow the same pattern that was established with commit "dm: ensure bio submission follows a depth-first tree walk". That is: submit first bio up to split boundary and then split the remainder to further submissions. Suggested-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-13dm: ensure bio-based DM's bioset and io_pool support targets' maximum IOsMike Snitzer1-10/+18
alloc_multiple_bios() assumes it can allocate the requested number of bios but until now there was no gaurantee that the mempools would be accomodating. Suggested-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-13dm: remove BIOSET_NEED_RESCUER based dm_offload infrastructureMike Snitzer1-59/+1
Now that all of DM has been revised and/or verified to no longer require the use of BIOSET_NEED_RESCUER the dm_offload code may be removed. Suggested-by: NeilBrown <neilb@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-13dm: safely allocate multiple bioset biosMike Snitzer1-12/+57
DM targets can request multiple bios be sent to them by DM core (see: num_{flush,discard,write_same,write_zeroes}_bios). But until now these bios were allocated in an unsafe manner than could potentially exhaust the DM device's bioset -- in the face of multiple threads each trying to do multiple allocations from the same DM device's bioset. Fix __send_duplicate_bios() by using the new alloc_multiple_bios(). The allocation strategy used by alloc_multiple_bios() models that used by dm-crypt.c:crypt_alloc_buffer(). Neil Brown initially proposed this fix but the implementation has been revised enough that it inappropriate to attribute the entirety of it to him. Suggested-by: NeilBrown <neilb@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-13dm: remove unused 'num_write_bios' target interfaceNeilBrown1-20/+10
No DM target provides num_write_bios and none has since dm-cache's brief use in 2013. Having the possibility of num_write_bios > 1 complicates bio allocation. So remove the interface and assume there is only one bio needed. If a target ever needs more, it must provide a suitable bioset and allocate itself based on its particular needs. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-13dm: ensure bio submission follows a depth-first tree walkNeilBrown1-9/+24
A dm device can, in general, represent a tree of targets, each of which handles a sub-range of the range of blocks handled by the parent. The bio sequencing managed by generic_make_request() requires that bios are generated and handled in a depth-first manner. Each call to a make_request_fn() may submit bios to a single member device, and may submit bios for a reduced region of the same device as the make_request_fn. In particular, any bios submitted to member devices must be expected to be processed in order, so a later one must never wait for an earlier one. This ordering is usually achieved by using bio_split() to reduce a bio to a size that can be completely handled by one target, and resubmitting the remainder to the originating device. bio_queue_split() shows the canonical approach. dm doesn't follow this approach, largely because it has needed to split bios since long before bio_split() was available. It currently can submit bios to separate targets within the one dm_make_request() call. Dependencies between these targets, as can happen with dm-snap, can cause deadlocks if either bios gets stuck behind the other in the queues managed by generic_make_request(). This requires the 'rescue' functionality provided by dm_offload_{start,end}. Some of this requirement can be removed by changing the order of bio submission to follow the canonical approach. That is, if dm finds that it needs to split a bio, the remainder should be sent to generic_make_request() rather than being handled immediately. This delays the handling until the first part is completely processed, so the deadlock problems do not occur. __split_and_process_bio() can be called both from dm_make_request() and from dm_wq_work(). When called from dm_wq_work() the current approach is perfectly satisfactory as each bio will be processed immediately. When called from dm_make_request(), current->bio_list will be non-NULL, and in this case it is best to create a separate "clone" bio for the remainder. When we use bio_clone_bioset() to split off the front part of a bio and chain the two together and submit the remainder to generic_make_request(), it is important that the newly allocated bio is used as the head to be processed immediately, and the original bio gets "bio_advance()"d and sent to generic_make_request() as the remainder. Otherwise, if the newly allocated bio is used as the remainder, and if it then needs to be split again, then the next bio_clone_bioset() call will be made while holding a reference a bio (result of the first clone) from the same bioset. This can potentially exhaust the bioset mempool and result in a memory allocation deadlock. Note that there is no race caused by reassigning cio.io->bio after already calling __map_bio(). This bio will only be dereferenced again after dec_pending() has found io->io_count to be zero, and this cannot happen before the dec_pending() call at the end of __split_and_process_bio(). To provide the clone bio when splitting, we use q->bio_split. This was previously being freed by bio-based dm to avoid having excess rescuer threads. As bio_split bio sets no longer create rescuer threads, there is little cost and much gain from restoring the q->bio_split bio set. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-12-13dm: fix comment above dm_accept_partial_bioNeilBrown1-1/+1
Clarify that dm_accept_partial_bio isn't allowed for REQ_OP_ZONE_RESET bios. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-14Merge tag 'for-4.15/dm' of ↵Linus Torvalds1-22/+23
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - a few conversions from atomic_t to ref_count_t - a DM core fix for a race during device destruction that could result in a BUG_ON - a stable@ fix for a DM cache race condition that could lead to data corruption when operating in writeback mode (writethrough is default) - various DM cache cleanups and improvements - add DAX support to the DM log-writes target - a fix for the DM zoned target's ability to deal with the last zone of the drive being smaller than all others - a stable@ DM crypt and DM integrity fix for a negative check that was to restrictive (prevented slab debug with XFS ontop of DM crypt from working) - a DM raid target fix for a panic that can occur when forcing a raid to sync * tag 'for-4.15/dm' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (25 commits) dm cache: lift common migration preparation code to alloc_migration() dm cache: remove usused deferred_cells member from struct cache dm cache policy smq: allocate cache blocks in order dm cache policy smq: change max background work from 10240 to 4096 blocks dm cache background tracker: limit amount of background work that may be issued at once dm cache policy smq: take origin idle status into account when queuing writebacks dm cache policy smq: handle races with queuing background_work dm raid: fix panic when attempting to force a raid to sync dm integrity: allow unaligned bv_offset dm crypt: allow unaligned bv_offset dm: small cleanup in dm_get_md() dm: fix race between dm_get_from_kobject() and __dm_destroy() dm: allocate struct mapped_device with kvzalloc dm zoned: ignore last smaller runt zone dm space map metadata: use ARRAY_SIZE dm log writes: add support for DAX dm log writes: add support for inline data buffers dm cache: simplify get_per_bio_data() by removing data_size argument dm cache: remove all obsolete writethrough-specific code dm cache: submit writethrough writes in parallel to origin and cache ...
2017-11-14Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-blockLinus Torvalds1-11/+0
Pull core block layer updates from Jens Axboe: "This is the main pull request for block storage for 4.15-rc1. Nothing out of the ordinary in here, and no API changes or anything like that. Just various new features for drivers, core changes, etc. In particular, this pull request contains: - A patch series from Bart, closing the whole on blk/scsi-mq queue quescing. - A series from Christoph, building towards hidden gendisks (for multipath) and ability to move bio chains around. - NVMe - Support for native multipath for NVMe (Christoph). - Userspace notifications for AENs (Keith). - Command side-effects support (Keith). - SGL support (Chaitanya Kulkarni) - FC fixes and improvements (James Smart) - Lots of fixes and tweaks (Various) - bcache - New maintainer (Michael Lyle) - Writeback control improvements (Michael) - Various fixes (Coly, Elena, Eric, Liang, et al) - lightnvm updates, mostly centered around the pblk interface (Javier, Hans, and Rakesh). - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph) - Writeback series that fix the much discussed hundreds of millions of sync-all units. This goes all the way, as discussed previously (me). - Fix for missing wakeup on writeback timer adjustments (Yafang Shao). - Fix laptop mode on blk-mq (me). - {mq,name} tupple lookup for IO schedulers, allowing us to have alias names. This means you can use 'deadline' on both !mq and on mq (where it's called mq-deadline). (me). - blktrace race fix, oopsing on sg load (me). - blk-mq optimizations (me). - Obscure waitqueue race fix for kyber (Omar). - NBD fixes (Josef). - Disable writeback throttling by default on bfq, like we do on cfq (Luca Miccio). - Series from Ming that enable us to treat flush requests on blk-mq like any other request. This is a really nice cleanup. - Series from Ming that improves merging on blk-mq with schedulers, getting us closer to flipping the switch on scsi-mq again. - BFQ updates (Paolo). - blk-mq atomic flags memory ordering fixes (Peter Z). - Loop cgroup support (Shaohua). - Lots of minor fixes from lots of different folks, both for core and driver code" * 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits) nvme: fix visibility of "uuid" ns attribute blk-mq: fixup some comment typos and lengths ide: ide-atapi: fix compile error with defining macro DEBUG blk-mq: improve tag waiting setup for non-shared tags brd: remove unused brd_mutex blk-mq: only run the hardware queue if IO is pending block: avoid null pointer dereference on null disk fs: guard_bio_eod() needs to consider partitions xtensa/simdisk: fix compile error nvme: expose subsys attribute to sysfs nvme: create 'slaves' and 'holders' entries for hidden controllers block: create 'slaves' and 'holders' entries for hidden gendisks nvme: also expose the namespace identification sysfs files for mpath nodes nvme: implement multipath access to nvme subsystems nvme: track shared namespaces nvme: introduce a nvme_ns_ids structure nvme: track subsystems block, nvme: Introduce blk_mq_req_flags_t block, scsi: Make SCSI quiesce and resume work reliably block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag ...
2017-11-10dm: small cleanup in dm_get_md()Mike Snitzer1-10/+5
Makes dm_get_md() and dm_get_from_kobject() have similar code. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm: fix race between dm_get_from_kobject() and __dm_destroy()Hou Tao1-4/+8
The following BUG_ON was hit when testing repeat creation and removal of DM devices: kernel BUG at drivers/md/dm.c:2919! CPU: 7 PID: 750 Comm: systemd-udevd Not tainted 4.1.44 Call Trace: [<ffffffff81649e8b>] dm_get_from_kobject+0x34/0x3a [<ffffffff81650ef1>] dm_attr_show+0x2b/0x5e [<ffffffff817b46d1>] ? mutex_lock+0x26/0x44 [<ffffffff811df7f5>] sysfs_kf_seq_show+0x83/0xcf [<ffffffff811de257>] kernfs_seq_show+0x23/0x25 [<ffffffff81199118>] seq_read+0x16f/0x325 [<ffffffff811de994>] kernfs_fop_read+0x3a/0x13f [<ffffffff8117b625>] __vfs_read+0x26/0x9d [<ffffffff8130eb59>] ? security_file_permission+0x3c/0x44 [<ffffffff8117bdb8>] ? rw_verify_area+0x83/0xd9 [<ffffffff8117be9d>] vfs_read+0x8f/0xcf [<ffffffff81193e34>] ? __fdget_pos+0x12/0x41 [<ffffffff8117c686>] SyS_read+0x4b/0x76 [<ffffffff817b606e>] system_call_fastpath+0x12/0x71 The bug can be easily triggered, if an extra delay (e.g. 10ms) is added between the test of DMF_FREEING & DMF_DELETING and dm_get() in dm_get_from_kobject(). To fix it, we need to ensure the test of DMF_FREEING & DMF_DELETING and dm_get() are done in an atomic way, so _minor_lock is used. The other callers of dm_get() have also been checked to be OK: some callers invoke dm_get() under _minor_lock, some callers invoke it under _hash_lock, and dm_start_request() invoke it after increasing md->open_count. Cc: stable@vger.kernel.org Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm: allocate struct mapped_device with kvzallocMikulas Patocka1-3/+3
The structure srcu_struct can be very big, its size is proportional to the value CONFIG_NR_CPUS. The Fedora kernel has CONFIG_NR_CPUS 8192, the field io_barrier in the struct mapped_device has 84kB in the debugging kernel and 50kB in the non-debugging kernel. The large size may result in failure of the function kzalloc_node. In order to avoid the allocation failure, we use the function kvzalloc_node, this function falls back to vmalloc if a large contiguous chunk of memory is not available. This patch also moves the field io_barrier to the last position of struct mapped_device - the reason is that on many processor architectures, short memory offsets result in smaller code than long memory offsets - on x86-64 it reduces code size by 320 bytes. Note to stable kernel maintainers - the kernels 4.11 and older don't have the function kvzalloc_node, you can use the function vzalloc_node instead. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland1-2/+2
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-24dm: convert table_device.count from atomic_t to refcount_tElena Reshetova1-5/+7
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable table_device.count is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-10-05block: remove QUEUE_FLAG_STACKABLEChristoph Hellwig1-11/+0
We already have a queue_is_rq_based helper to check if a request_queue is request based, so we can remove the flag for it. Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25dm ioctl: fix alignment of event number in the device listMikulas Patocka1-2/+8
The size of struct dm_name_list is different on 32-bit and 64-bit kernels (so "(nl + 1)" differs between 32-bit and 64-bit kernels). This mismatch caused some harmless difference in padding when using 32-bit or 64-bit kernel. Commit 23d70c5e52dd ("dm ioctl: report event number in DM_LIST_DEVICES") added reporting event number in the output of DM_LIST_DEVICES_CMD. This difference in padding makes it impossible for userspace to determine the location of the event number (the location would be different when running on 32-bit and 64-bit kernels). Fix the padding by using offsetof(struct dm_name_list, name) instead of sizeof(struct dm_name_list) to determine the location of entries. Also, the ioctl version number is incremented to 37 so that userspace can use the version number to determine that the event number is present and correctly located. In addition, a global event is now raised when a DM device is created, removed, renamed or when table is swapped, so that the user can monitor for device changes. Reported-by: Eugene Syromiatnikov <esyr@redhat.com> Fixes: 23d70c5e52dd ("dm ioctl: report event number in DM_LIST_DEVICES") Cc: stable@vger.kernel.org # 4.13 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-09-14Merge tag 'for-4.14/dm-changes' of ↵Linus Torvalds1-19/+0
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Some request-based DM core and DM multipath fixes and cleanups - Constify a few variables in DM core and DM integrity - Add bufio optimization and checksum failure accounting to DM integrity - Fix DM integrity to avoid checking integrity of failed reads - Fix DM integrity to use init_completion - A couple DM log-writes target fixes - Simplify DAX flushing by eliminating the unnecessary flush abstraction that was stood up for DM's use. * tag 'for-4.14/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dax: remove the pmem_dax_ops->flush abstraction dm integrity: use init_completion instead of COMPLETION_INITIALIZER_ONSTACK dm integrity: make blk_integrity_profile structure const dm integrity: do not check integrity for failed read operations dm log writes: fix >512b sectorsize support dm log writes: don't use all the cpu while waiting to log blocks dm ioctl: constify ioctl lookup table dm: constify argument arrays dm integrity: count and display checksum failures dm integrity: optimize writing dm-bufio buffers that are partially changed dm rq: do not update rq partially in each ending bio dm rq: make dm-sq requeuing behavior consistent with dm-mq behavior dm mpath: complain about unsupported __multipath_map_bio() return values dm mpath: avoid that building with W=1 causes gcc 7 to complain about fall-through
2017-09-11dax: remove the pmem_dax_ops->flush abstractionMikulas Patocka1-19/+0
Commit abebfbe2f731 ("dm: add ->flush() dax operation support") is buggy. A DM device may be composed of multiple underlying devices and all of them need to be flushed. That commit just routes the flush request to the first device and ignores the other devices. It could be fixed by adding more complex logic to the device mapper. But there is only one implementation of the method pmem_dax_ops->flush - that is pmem_dax_flush() - and it calls arch_wb_cache_pmem(). Consequently, we don't need the pmem_dax_ops->flush abstraction at all, we can call arch_wb_cache_pmem() directly from dax_flush() because dax_dev->ops->flush can't ever reach anything different from arch_wb_cache_pmem(). It should be also pointed out that for some uses of persistent memory it is needed to flush only a very small amount of data (such as 1 cacheline), and it would be overkill if we go through that device mapper machinery for a single flushed cache line. Fix this by removing the pmem_dax_ops->flush abstraction and call arch_wb_cache_pmem() directly from dax_flush(). Also, remove the device mapper code that forwards the flushes. Fixes: abebfbe2f731 ("dm: add ->flush() dax operation support") Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-09-07Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-blockLinus Torvalds1-8/+8
Pull block layer updates from Jens Axboe: "This is the first pull request for 4.14, containing most of the code changes. It's a quiet series this round, which I think we needed after the churn of the last few series. This contains: - Fix for a registration race in loop, from Anton Volkov. - Overflow complaint fix from Arnd for DAC960. - Series of drbd changes from the usual suspects. - Conversion of the stec/skd driver to blk-mq. From Bart. - A few BFQ improvements/fixes from Paolo. - CFQ improvement from Ritesh, allowing idling for group idle. - A few fixes found by Dan's smatch, courtesy of Dan. - A warning fixup for a race between changing the IO scheduler and device remova. From David Jeffery. - A few nbd fixes from Josef. - Support for cgroup info in blktrace, from Shaohua. - Also from Shaohua, new features in the null_blk driver to allow it to actually hold data, among other things. - Various corner cases and error handling fixes from Weiping Zhang. - Improvements to the IO stats tracking for blk-mq from me. Can drastically improve performance for fast devices and/or big machines. - Series from Christoph removing bi_bdev as being needed for IO submission, in preparation for nvme multipathing code. - Series from Bart, including various cleanups and fixes for switch fall through case complaints" * 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits) kernfs: checking for IS_ERR() instead of NULL drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set drbd: Fix allyesconfig build, fix recent commit drbd: switch from kmalloc() to kmalloc_array() drbd: abort drbd_start_resync if there is no connection drbd: move global variables to drbd namespace and make some static drbd: rename "usermode_helper" to "drbd_usermode_helper" drbd: fix race between handshake and admin disconnect/down drbd: fix potential deadlock when trying to detach during handshake drbd: A single dot should be put into a sequence. drbd: fix rmmod cleanup, remove _all_ debugfs entries drbd: Use setup_timer() instead of init_timer() to simplify the code. drbd: fix potential get_ldev/put_ldev refcount imbalance during attach drbd: new disk-option disable-write-same drbd: Fix resource role for newly created resources in events2 drbd: mark symbols static where possible drbd: Send P_NEG_ACK upon write error in protocol != C drbd: add explicit plugging when submitting batches drbd: change list_for_each_safe to while(list_first_entry_or_null) drbd: introduce drbd_recv_header_maybe_unplug ...
2017-08-28dm: fix printk() rate limiting codeBart Van Assche1-10/+0
Using the same rate limiting state for different kinds of messages is wrong because this can cause a high frequency message to suppress a report of a low frequency message. Hence use a unique rate limiting state per message type. Fixes: 71a16736a15e ("dm: use local printk ratelimit") Cc: stable@vger.kernel.org Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-08-28dm: fix the second dec_pending() argument in __split_and_process_bio()Bart Van Assche1-1/+1
Detected by sparse. Fixes: 4e4cbee93d56 ("block: switch bios to blk_status_t") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig1-5/+5
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>
2017-08-09block: pass in queue to inflight accountingJens Axboe1-3/+3
No functional change in this patch, just in preparation for basing the inflight mechanism on the queue in question. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>