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path: root/drivers/nvdimm/region_devs.c
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11 daysnvdimm: virtio_pmem: stop allocating child flush bioLi Chen
pmem_submit_bio() passes the parent bio to nvdimm_flush() for REQ_FUA. For virtio-pmem this makes async_pmem_flush() allocate and submit a child PREFLUSH bio chained to the parent. That child allocation is in the block submit path. Making it blocking with GFP_NOIO can consume the same global bio mempool that submit_bio() uses, while making it GFP_ATOMIC can fail under pressure. A forced failure of the child allocation produced: virtio_pmem: forcing child bio allocation failure for test Buffer I/O error on dev pmem0, logical block 0, lost sync page write EXT4-fs (pmem0): I/O error while writing superblock EXT4-fs (pmem0): mount failed Avoid the child bio without turning REQ_FUA into a synchronous submit-path wait. Let provider flush callbacks return NVDIMM_FLUSH_ASYNC after taking ownership of parent bio completion. pmem_submit_bio() returns in that case, and virtio-pmem queues an ordered WQ_MEM_RECLAIM work item that runs the existing host flush path and completes the parent bio. This keeps the asynchronous completion model of the child-bio path while removing the child bio allocation from the submit path. Signed-off-by: Li Chen <me@linux.beauty> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260630092338.2094628-5-me@linux.beauty>
11 daysnvdimm: preserve flush callback -ENOMEMLi Chen
nvdimm_flush() maps provider flush failures to -EIO. Keep that default because provider callbacks can report host-side or backend failures that should remain generic I/O errors to the guest. Guest-side allocation failures should not be reported as I/O errors. In the virtio-pmem path, the flush request allocation can fail with -ENOMEM before any request is submitted to the host. Mapping that to -EIO makes resource pressure look like media failure. Preserve -ENOMEM from provider callbacks and continue to map other non-zero provider failures to -EIO. The generic flush path still returns 0, and pmem_submit_bio() already converts errno values to block status for bio completion. Suggested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: Li Chen <me@linux.beauty> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260630092338.2094628-2-me@linux.beauty>
2026-06-01nvdimm/btt: Handle preemption in BTT lane acquisitionAlison Schofield
BTT lanes serialize access to per-lane metadata and workspace state during BTT I/O. The btt-check unit test reports data mismatches during BTT writes due to a race in lane acquisition that can lead to silent data corruption. The existing lane model uses a spinlock together with a per-CPU recursion count. That recursion model stopped being valid after BTT lanes became preemptible: another task can run on the same CPU, observe a non-zero recursion count, bypass locking, and use the same lane concurrently. BTT lanes are also held across arena_write_bytes() calls. That path reaches nsio_rw_bytes(), which flushes writes with nvdimm_flush(). Some provider flush callbacks can sleep, making a spinlock the wrong primitive for the lane lifetime. Replace the spinlock-based recursion model with a dynamically allocated per-lane mutex array and take the lane lock unconditionally. Add might_sleep() to catch any future atomic-context caller. Found with the ndctl unit test btt-check.sh. Fixes: 36c75ce3bd29 ("nd_btt: Make BTT lanes preemptible") Assisted-by: Claude-Sonnet:4.5 Tested-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Reviewed-by: Aboorva Devarajan <aboorvad@linux.ibm.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://patch.msgid.link/20260528021625.618462-1-alison.schofield@intel.com Signed-off-by: Alison Schofield <alison.schofield@intel.com>
2026-02-21Convert more 'alloc_obj' cases to default GFP_KERNEL argumentsLinus Torvalds
This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2025-11-27Merge tag 'cache-for-v6.19' of ↵Arnd Bergmann
https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux into soc/drivers-late standalone cache drivers for v6.19 ccache: Add a compatible for the pic64gx SoC. No driver change needed, as it falls back to the PolarFire SoC. hisi hha/generic cpu cache maintenance: Add support for a non-architectural mechanism for invalidating memory regions, needed for some cxl implementations on arm64 (and probably elsewhere in the future). The HiSilicon Hydra Home Agent is the first driver to provide this support. Signed-off-by: Conor Dooley <conor.dooley@microchip.com> * tag 'cache-for-v6.19' of https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux: MAINTAINERS: refer to intended file in STANDALONE CACHE CONTROLLER DRIVERS cache: Support cache maintenance for HiSilicon SoC Hydra Home Agent cache: Make top level Kconfig menu a boolean dependent on RISCV MAINTAINERS: Add Jonathan Cameron to drivers/cache and add lib/cache_maint.c + header arm64: Select GENERIC_CPU_CACHE_MAINTENANCE lib: Support ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION memregion: Support fine grained invalidate by cpu_cache_invalidate_memregion() memregion: Drop unused IORES_DESC_* parameter from cpu_cache_invalidate_memregion() dt-bindings: cache: sifive,ccache0: add a pic64gx compatible Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2025-11-17memregion: Support fine grained invalidate by cpu_cache_invalidate_memregion()Yicong Yang
Extend cpu_cache_invalidate_memregion() to support invalidating a particular range of memory by introducing start and length parameters. Control of types of invalidation is left for when use cases turn up. For now everything is Clean and Invalidate. Where the range is unknown, use the provided cpu_cache_invalidate_all() helper to act as documentation of intent in a fashion that is clearer than passing (0, -1) to cpu_cache_invalidate_memregion(). Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2025-11-17memregion: Drop unused IORES_DESC_* parameter from ↵Jonathan Cameron
cpu_cache_invalidate_memregion() The res_desc parameter was originally introduced for documentation purposes and with the idea that with HDM-DB CXL invalidation could be triggered from the device. That has not come to pass and the continued existence of the option is confusing when we add a range in the following patch which might not be a strict subset of the res_desc. So avoid that confusion by dropping the parameter. Link: https://lore.kernel.org/linux-mm/686eedb25ed02_24471002e@dwillia2-xfh.jf.intel.com.notmuch/ Reviewed-by: Dan Williams <dan.j.williams@intel.com> Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2025-09-25nvdimm: Introduce guard() for nvdimm_bus_lockDave Jiang
Converting nvdimm_bus_lock/unlock to guard() to clean up usage of gotos for error handling and avoid future mistakes of missed unlock on error paths. Link: https://lore.kernel.org/linux-cxl/20250917163623.00004a3c@huawei.com/ Suggested-by: Jonathan Cameron <jonathan.cameron@huawei.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
2025-03-03libnvdimm: Remove unused nd_region_conflictDr. David Alan Gilbert
nd_region_conflict() has been unused since 2019's commit a3619190d62e ("libnvdimm/pfn: stop padding pmem namespaces to section alignment") Remove it, and the region_confict() helper it uses, and the associated struct conflict_context. Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/20250220004538.84585-2-linux@treblig.org Signed-off-by: Ira Weiny <ira.weiny@intel.com>
2024-12-02module: Convert symbol namespace to string literalPeter Zijlstra
Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-09-27libnvdimm: Annotate struct nd_region with __counted_byKees Cook
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct nd_region. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: nvdimm@lists.linux.dev Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
2023-09-27nd_btt: Make BTT lanes preemptibleTomas Glozar
nd_region_acquire_lane uses get_cpu, which disables preemption. This is an issue on PREEMPT_RT kernels, since btt_write_pg and also nd_region_acquire_lane itself take a spin lock, resulting in BUG: sleeping function called from invalid context. Fix the issue by replacing get_cpu with smp_process_id and migrate_disable when needed. This makes BTT operations preemptible, thus permitting the use of spin_lock. BUG example occurring when running ndctl tests on PREEMPT_RT kernel: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 4903, name: libndctl preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 Preemption disabled at: [<ffffffffc1313db5>] nd_region_acquire_lane+0x15/0x90 [libnvdimm] Call Trace: <TASK> dump_stack_lvl+0x8e/0xb0 __might_resched+0x19b/0x250 rt_spin_lock+0x4c/0x100 ? btt_write_pg+0x2d7/0x500 [nd_btt] btt_write_pg+0x2d7/0x500 [nd_btt] ? local_clock_noinstr+0x9/0xc0 btt_submit_bio+0x16d/0x270 [nd_btt] __submit_bio+0x48/0x80 __submit_bio_noacct+0x7e/0x1e0 submit_bio_wait+0x58/0xb0 __blkdev_direct_IO_simple+0x107/0x240 ? inode_set_ctime_current+0x51/0x110 ? __pfx_submit_bio_wait_endio+0x10/0x10 blkdev_write_iter+0x1d8/0x290 vfs_write+0x237/0x330 ... </TASK> Fixes: 5212e11fde4d ("nd_btt: atomic sector updates") Signed-off-by: Tomas Glozar <tglozar@redhat.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
2023-07-19nvdimm: Use kstrtobool() instead of strtobool()Christophe JAILLET
strtobool() is the same as kstrtobool(). However, the latter is more used within the kernel. In order to remove strtobool() and slightly simplify kstrtox.h, switch to the other function name. While at it, include the corresponding header file (<linux/kstrtox.h>) Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2023-01-27driver core: make struct bus_type.uevent() take a const *Greg Kroah-Hartman
The uevent() callback in struct bus_type should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-02nvdimm/region: Move cache management to the region driverDan Williams
Now that cpu_cache_invalidate_memregion() is generically available, use it to centralize CPU cache management in the nvdimm region driver. This trades off removing redundant per-dimm CPU cache flushing with an opportunistic flush on every region disable event to cover the case of sensitive dirty data in the cache being written back to media after a secure erase / overwrite event. Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/166993221550.1995348.16843505129579060258.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-09-29libnvdimm/region: Allow setting align attribute on regions without mappingsTyler Hicks
The alignment constraint for namespace creation in a region was increased, from 2M to 16M, for non-PowerPC architectures in v5.7 with commit 2522afb86a8c ("libnvdimm/region: Introduce an 'align' attribute"). The thought behind the change was that region alignment should be uniform across all architectures and, since PowerPC had the largest alignment constraint of 16M, all architectures should conform to that alignment. The change regressed namespace creation in pre-defined regions that relied on 2M alignment but a workaround was provided in the form of a sysfs attribute, named 'align', that could be adjusted to a non-default alignment value. However, the sysfs attribute's store function returned an error (-ENXIO) when userspace attempted to change the alignment of a region that had no mappings. This affected 2M aligned regions of volatile memory that were defined in a device tree using "pmem-region" and created by the of_pmem_region_driver, since those regions do not contain mappings (ndr_mappings is 0). Allow userspace to set the align attribute on pre-existing regions that do not have mappings so that namespaces can still be within those regions, despite not being aligned to 16M. Link: https://lore.kernel.org/lkml/CA+CK2bDJ3hrWoE91L2wpAk+Yu0_=GtYw=4gLDDD7mxs321b_aA@mail.gmail.com Fixes: 2522afb86a8c ("libnvdimm/region: Introduce an 'align' attribute") Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Link: https://lore.kernel.org/r/20220830054505.1159488-1-tyhicks@linux.microsoft.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-09-20nvdimm/region: Fix kernel-docJiapeng Chong
drivers/nvdimm/region_devs.c:1103: warning: expecting prototype for nvdimm_flush(). Prototype was for generic_nvdimm_flush() instead. Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2209 Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Link: https://lore.kernel.org/r/20220919061428.102883-1-jiapeng.chong@linux.alibaba.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-07-26cxl/region: Introduce cxl_pmem_region objectsDan Williams
The LIBNVDIMM subsystem is a platform agnostic representation of system NVDIMM / persistent memory resources. To date, the CXL subsystem's interaction with LIBNVDIMM has been to register an nvdimm-bridge device and cxl_nvdimm objects to proxy CXL capabilities into existing LIBNVDIMM subsystem mechanics. With regions the approach is the same. Create a new cxl_pmem_region object to proxy CXL region details into a LIBNVDIMM definition. With this enabling LIBNVDIMM can partition CXL persistent memory regions with legacy namespace labels. A follow-on patch will add CXL region label and CXL namespace label support to persist region configurations across driver reload / system-reset events. Co-developed-by: Ben Widawsky <bwidawsk@kernel.org> Signed-off-by: Ben Widawsky <bwidawsk@kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/165784340111.1758207.3036498385188290968.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-28nvdimm: Drop nd_device_lock()Dan Williams
Now that all NVDIMM subsystem locking is validated with custom lock classes, there is no need for the custom usage of the lockdep_mutex. Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165055521979.3745911.10751769706032029999.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-04-28nvdimm: Replace lockdep_mutex with local lock classesDan Williams
In response to an attempt to expand dev->lockdep_mutex for device_lock() validation [1], Peter points out [2] that the lockdep API already has the ability to assign a dedicated lock class per subsystem device-type. Use lockdep_set_class() to override the default device_lock() '__lockdep_no_validate__' class for each NVDIMM subsystem device-type. This enables lockdep to detect deadlocks and recursive locking within the device-driver core and the subsystem. Link: https://lore.kernel.org/r/164982968798.684294.15817853329823976469.stgit@dwillia2-desk3.amr.corp.intel.com [1] Link: https://lore.kernel.org/r/Ylf0dewci8myLvoW@hirez.programming.kicks-ass.net [2] Suggested-by: Peter Zijlstra <peterz@infradead.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/165055520896.3745911.8021255583475547548.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-03-11nvdimm/region: Delete nd_blk_region infrastructureDan Williams
Now that the nd_namespace_blk infrastructure is removed, delete all the region machinery to coordinate provisioning aliased capacity between PMEM and BLK. Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/164688418803.2879318.1302315202397235855.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-03-11nvdimm/region: Fix default alignment for small regionsDan Williams
In preparation for removing BLK aperture support the NVDIMM unit tests discovered that the default alignment can be set higher than the capacity of the region. Fall back to PAGE_SIZE in that case. Given this has not been seen in the wild, elide notifying -stable. Fixes: 2522afb86a8c ("libnvdimm/region: Introduce an 'align' attribute") Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/164688416128.2879318.17890707310125575258.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-04-09libnvdimm/region: Fix nvdimm_has_flush() to handle ND_REGION_ASYNCVaibhav Jain
In case a platform doesn't provide explicit flush-hints but provides an explicit flush callback via ND_REGION_ASYNC region flag, then nvdimm_has_flush() still returns '0' indicating that writes do not require flushing. This happens on PPC64 with patch at [1] applied, where 'deep_flush' of a region was denied even though an explicit flush function was provided. Fix this by adding a condition to nvdimm_has_flush() to test for the ND_REGION_ASYNC flag on the region and see if a 'region->flush' callback is assigned. Link: http://lore.kernel.org/r/161703936121.36.7260632399582101498.stgit@e1fbed493c87 [1] Fixes: c5d4355d10d4 ("libnvdimm: nd_region flush callback support") Reported-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> Link: https://lore.kernel.org/r/20210402092555.208590-1-vaibhav@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-04-08libnvdimm: Notify disk drivers to revalidate region read-onlyDan Williams
Previous kernels allowed the BLKROSET to override the disk's read-only status. With that situation fixed the pmem driver needs to rely on notification events to reevaluate the disk read-only status after the host region has been marked read-write. Recall that when libnvdimm determines that the persistent memory has lost persistence (for example lack of energy to flush from DRAM to FLASH on an NVDIMM-N device) it marks the region read-only, but that state can be overridden by the user via: echo 0 > /sys/bus/nd/devices/regionX/read_only ...to date there is no notification that the region has restored persistence, so the user override is the only recovery. Fixes: 52f019d43c22 ("block: add a hard-readonly flag to struct gendisk") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Vishal Verma <vishal.l.verma@intel.com> Tested-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/161534060720.528671.2341213328968989192.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-08-11Merge tag 'libnvdimm-for-5.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updayes from Vishal Verma: "You'd normally receive this pull request from Dan Williams, but he's busy watching a newborn (Congrats Dan!), so I'm watching libnvdimm this cycle. This adds a new feature in libnvdimm - 'Runtime Firmware Activation', and a few small cleanups and fixes in libnvdimm and DAX. I'd originally intended to make separate topic-based pull requests - one for libnvdimm, and one for DAX, but some of the DAX material fell out since it wasn't quite ready. Summary: - add 'Runtime Firmware Activation' support for NVDIMMs that advertise the relevant capability - misc libnvdimm and DAX cleanups" * tag 'libnvdimm-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm/security: ensure sysfs poll thread woke up and fetch updated attr libnvdimm/security: the 'security' attr never show 'overwrite' state libnvdimm/security: fix a typo ACPI: NFIT: Fix ARS zero-sized allocation dax: Fix incorrect argument passed to xas_set_err() ACPI: NFIT: Add runtime firmware activate support PM, libnvdimm: Add runtime firmware activation support libnvdimm: Convert to DEVICE_ATTR_ADMIN_RO() drivers/dax: Expand lock scope to cover the use of addresses fs/dax: Remove unused size parameter dax: print error message by pr_info() in __generic_fsdax_supported() driver-core: Introduce DEVICE_ATTR_ADMIN_{RO,RW} tools/testing/nvdimm: Emulate firmware activation commands tools/testing/nvdimm: Prepare nfit_ctl_test() for ND_CMD_CALL emulation tools/testing/nvdimm: Add command debug messages tools/testing/nvdimm: Cleanup dimm index passing ACPI: NFIT: Define runtime firmware activation commands ACPI: NFIT: Move bus_dsm_mask out of generic nvdimm_bus_descriptor libnvdimm: Validate command family indices
2020-07-28libnvdimm: Convert to DEVICE_ATTR_ADMIN_RO()Dan Williams
Move libnvdimm sysfs attributes that currently use an open coded DEVICE_ATTR() to hide sensitive root-only information (physical memory layout) to the new DEVICE_ATTR_ADMIN_RO() helper. Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2020-07-16libnvdimm/nvdimm/flush: Allow architecture to override the flush barrierAneesh Kumar K.V
Architectures like ppc64 provide persistent memory specific barriers that will ensure that all stores for which the modifications are written to persistent storage by preceding dcbfps and dcbstps instructions have updated persistent storage before any data access or data transfer caused by subsequent instructions is initiated. This is in addition to the ordering done by wmb() Update nvdimm core such that architecture can use barriers other than wmb to ensure all previous writes are architecturally visible for the platform buffer flush. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-5-aneesh.kumar@linux.ibm.com
2020-06-17nvdimm/region: always show the 'align' attributeVishal Verma
It is possible that a platform that is capable of 'namespace labels' comes up without the labels properly initialized. In this case, the region's 'align' attribute is hidden. Howerver, once the user does initialize he labels, the 'align' attribute still stays hidden, which is unexpected. The sysfs_update_group() API is meant to address this, and could be called during region probe, but it has entanglements with the device 'lockdep_mutex'. Therefore, simply make the 'align' attribute always visible. It doesn't matter what it says for label-less namespaces, since it is not possible to change their allocation anyway. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/20200520225026.29426-1-vishal.l.verma@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-03-31libnvdimm/region: Fix build errorYueHaibing
On CONFIG_PPC32=y build fails: drivers/nvdimm/region_devs.c:1034:14: note: in expansion of macro ‘do_div’ remainder = do_div(per_mapping, mappings); ^~~~~~ In file included from ./arch/powerpc/include/generated/asm/div64.h:1:0, from ./include/linux/kernel.h:18, from ./include/asm-generic/bug.h:19, from ./arch/powerpc/include/asm/bug.h:109, from ./include/linux/bug.h:5, from ./include/linux/scatterlist.h:7, from drivers/nvdimm/region_devs.c:5: ./include/asm-generic/div64.h:243:22: error: passing argument 1 of ‘__div64_32’ from incompatible pointer type [-Werror=incompatible-pointer-types] __rem = __div64_32(&(n), __base); \ Use div_u64 instead of do_div to fix this. Fixes: 2522afb86a8c ("libnvdimm/region: Introduce an 'align' attribute") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Link: https://lore.kernel.org/r/20200331115024.31628-1-yuehaibing@huawei.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-03-17libnvdimm/region: Introduce an 'align' attributeDan Williams
The align attribute applies an alignment constraint for namespace creation in a region. Whereas the 'align' attribute of a namespace applied alignment padding via an info block, the 'align' attribute applies alignment constraints to the free space allocation. The default for 'align' is the maximum known memremap_compat_align() across all archs (16MiB from PowerPC at time of writing) multiplied by the number of interleave ways if there is blk-aliasing. The minimum is PAGE_SIZE and allows for the creation of cross-arch incompatible namespaces, just as previous kernels allowed, but the expectation is cross-arch and mode-independent compatibility by default. The regression risk with this change is limited to cases that were dependent on the ability to create unaligned namespaces, *and* for some reason are unable to opt-out of aligned namespaces by writing to 'regionX/align'. If such a scenario arises the default can be flipped from opt-out to opt-in of compat-aligned namespace creation, but that is a last resort. The kernel will otherwise continue to support existing defined misaligned namespaces. Unfortunately this change needs to touch several parts of the implementation at once: - region/available_size: expand busy extents to current align - region/max_available_extent: expand busy extents to current align - namespace/size: trim free space to current align ...to keep the free space accounting conforming to the dynamic align setting. Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reported-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Link: https://lore.kernel.org/r/158041478371.3889308.14542630147672668068.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2020-03-17libnvdimm/region: Introduce NDD_LABELINGDan Williams
The NDD_ALIASING flag is used to indicate where pmem capacity might alias with blk capacity and require labeling. It is also used to indicate whether the DIMM supports labeling. Separate this latter capability into its own flag so that the NDD_ALIASING flag is scoped to true aliased configurations. To my knowledge aliased configurations only exist in the ACPI spec, there are no known platforms that ship this support in production. This clarity allows namespace-capacity alignment constraints around interleave-ways to be relaxed. Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/158041477856.3889308.4212605617834097674.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-12-01Merge tag 'libnvdimm-for-5.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The highlight this cycle is continuing integration fixes for PowerPC and some resulting optimizations. Summary: - Updates to better support vmalloc space restrictions on PowerPC platforms. - Cleanups to move common sysfs attributes to core 'struct device_type' objects. - Export the 'target_node' attribute (the effective numa node if pmem is marked online) for regions and namespaces. - Miscellaneous fixups and optimizations" * tag 'libnvdimm-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits) MAINTAINERS: Remove Keith from NVDIMM maintainers libnvdimm: Export the target_node attribute for regions and namespaces dax: Add numa_node to the default device-dax attributes libnvdimm: Simplify root read-only definition for the 'resource' attribute dax: Simplify root read-only definition for the 'resource' attribute dax: Create a dax device_type libnvdimm: Move nvdimm_bus_attribute_group to device_type libnvdimm: Move nvdimm_attribute_group to device_type libnvdimm: Move nd_mapping_attribute_group to device_type libnvdimm: Move nd_region_attribute_group to device_type libnvdimm: Move nd_numa_attribute_group to device_type libnvdimm: Move nd_device_attribute_group to device_type libnvdimm: Move region attribute group definition libnvdimm: Move attribute groups to device type libnvdimm: Remove prototypes for nonexistent functions libnvdimm/btt: fix variable 'rc' set but not used libnvdimm/pmem: Delete include of nd-core.h libnvdimm/namespace: Differentiate between probe mapping and runtime mapping libnvdimm/pfn_dev: Don't clear device memmap area during generic namespace probe libnvdimm: Trivial comment fix ...
2019-11-19libnvdimm: Simplify root read-only definition for the 'resource' attributeDan Williams
Rather than update the permission in ->is_visible() set the permission directly at declaration time. Cc: Ira Weiny <ira.weiny@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157309905534.1582359.13927459228885931097.stgit@dwillia2-desk3.amr.corp.intel.com
2019-11-19libnvdimm: Move nd_mapping_attribute_group to device_typeDan Williams
A 'struct device_type' instance can carry default attributes for the device. Use this facility to remove the export of nd_mapping_attribute_group and put the responsibility on the core rather than leaf implementations to define this attribute. Cc: Ira Weiny <ira.weiny@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157309902686.1582359.6749533709859492704.stgit@dwillia2-desk3.amr.corp.intel.com
2019-11-19libnvdimm: Move nd_region_attribute_group to device_typeDan Williams
A 'struct device_type' instance can carry default attributes for the device. Use this facility to remove the export of nd_region_attribute_group and put the responsibility on the core rather than leaf implementations to define this attribute. Cc: Ira Weiny <ira.weiny@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157309902169.1582359.16828508538444551337.stgit@dwillia2-desk3.amr.corp.intel.com
2019-11-19libnvdimm: Move nd_numa_attribute_group to device_typeDan Williams
A 'struct device_type' instance can carry default attributes for the device. Use this facility to remove the export of nd_numa_attribute_group and put the responsibility on the core rather than leaf implementations to define this attribute. Cc: Ira Weiny <ira.weiny@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157401269537.43284.14411189404186877352.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-11-17libnvdimm: Move nd_device_attribute_group to device_typeDan Williams
A 'struct device_type' instance can carry default attributes for the device. Use this facility to remove the export of nd_device_attribute_group and put the responsibility on the core rather than leaf implementations to define this attribute. For regions this creates a new nd_region_attribute_groups[] added to the per-region device-type instances. Cc: Ira Weiny <ira.weiny@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157309901138.1582359.12909354140826530394.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-11-17libnvdimm: Move region attribute group definitionDan Williams
In preparation for moving region attributes from device attribute groups to the region device-type, reorder the declaration so that it can be referenced by the device-type definition without forward declarations. No functional changes are intended to result from this change. Cc: Ira Weiny <ira.weiny@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157309900624.1582359.6929998072035982264.stgit@dwillia2-desk3.amr.corp.intel.com
2019-11-07lib: Uplevel the pmem "region" ida to a global allocatorDan Williams
In preparation for handling platform differentiated memory types beyond persistent memory, uplevel the "region" identifier to a global number space. This enables a device-dax instance to be registered to any memory type with guaranteed unique names. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-09-24libnvdimm/region: Enable MAP_SYNC for volatile regionsAneesh Kumar K.V
Some environments want to use a host tmpfs/ramdisk to back guest pmem. While the data is not persisted relative to the host it *is* persisted relative to guest crashes / reboots. The guest is free to use dax and MAP_SYNC to keep filesystem metadata consistent with dax accesses without requiring guest fsync(). The guest can also observe that the region is volatile and skip cache flushing as global visibility is enough to "persist" data relative to the host staying alive over guest reset events. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Link: https://lore.kernel.org/r/20190924114327.14700-1-aneesh.kumar@linux.ibm.com [djbw: reword the changelog] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-09-24libnvdimm/region: Initialize bad block for volatile namespacesAneesh Kumar K.V
We do check for a bad block during namespace init and that use region bad block list. We need to initialize the bad block for volatile regions for this to work. We also observe a lockdep warning as below because the lock is not initialized correctly since we skip bad block init for volatile regions. INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.3.0-rc1-15699-g3dee241c937e #149 Call Trace: [c0000000f95cb250] [c00000000147dd84] dump_stack+0xe8/0x164 (unreliable) [c0000000f95cb2a0] [c00000000022ccd8] register_lock_class+0x308/0xa60 [c0000000f95cb3a0] [c000000000229cc0] __lock_acquire+0x170/0x1ff0 [c0000000f95cb4c0] [c00000000022c740] lock_acquire+0x220/0x270 [c0000000f95cb580] [c000000000a93230] badblocks_check+0xc0/0x290 [c0000000f95cb5f0] [c000000000d97540] nd_pfn_validate+0x5c0/0x7f0 [c0000000f95cb6d0] [c000000000d98300] nd_dax_probe+0xd0/0x1f0 [c0000000f95cb760] [c000000000d9b66c] nd_pmem_probe+0x10c/0x160 [c0000000f95cb790] [c000000000d7f5ec] nvdimm_bus_probe+0x10c/0x240 [c0000000f95cb820] [c000000000d0f844] really_probe+0x254/0x4e0 [c0000000f95cb8b0] [c000000000d0fdfc] driver_probe_device+0x16c/0x1e0 [c0000000f95cb930] [c000000000d10238] device_driver_attach+0x68/0xa0 [c0000000f95cb970] [c000000000d1040c] __driver_attach+0x19c/0x1c0 [c0000000f95cb9f0] [c000000000d0c4c4] bus_for_each_dev+0x94/0x130 [c0000000f95cba50] [c000000000d0f014] driver_attach+0x34/0x50 [c0000000f95cba70] [c000000000d0e208] bus_add_driver+0x178/0x2f0 [c0000000f95cbb00] [c000000000d117c8] driver_register+0x108/0x170 [c0000000f95cbb70] [c000000000d7edb0] __nd_driver_register+0xe0/0x100 [c0000000f95cbbd0] [c000000001a6baa4] nd_pmem_driver_init+0x34/0x48 [c0000000f95cbbf0] [c0000000000106f4] do_one_initcall+0x1d4/0x4b0 [c0000000f95cbcd0] [c0000000019f499c] kernel_init_freeable+0x544/0x65c [c0000000f95cbdb0] [c000000000010d6c] kernel_init+0x2c/0x180 [c0000000f95cbe20] [c00000000000b954] ret_from_kernel_thread+0x5c/0x68 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/20190919083355.26340-1-aneesh.kumar@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-09-05libnvdimm: Use PAGE_SIZE instead of SZ_4K for align checkAneesh Kumar K.V
Architectures have different page size than 4K. Use the PAGE_SIZE to make sure ranges are correctly aligned. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/20190905154603.10349-7-aneesh.kumar@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-09-05libnvdimm/region: Rewrite _probe_success() to _advance_seeds()Dan Williams
The nd_region_probe_success() helper collides seed management with nvdimm->busy tracking. Given the 'busy' increment is handled internal to the nd_region driver 'probe' path move the decrement to the 'remove' path. With that cleanup the routine can be renamed to the more descriptive nd_region_advance_seeds(). The change is prompted by an incoming need to optionally advance the seeds on other events besides 'probe' success. Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/20190905154603.10349-2-aneesh.kumar@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-08-29libnvdimm, region: Use struct_size() in kzalloc()Gustavo A. R. Silva
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct nd_region { ... struct nd_mapping mapping[0]; }; instance = kzalloc(sizeof(struct nd_region) + sizeof(struct nd_mapping) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kzalloc(struct_size(instance, mapping, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20190610210613.GA21989@embeddedor Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-27Merge tag 'libnvdimm-fixes-5.3-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "A collection of locking and async operations fixes for v5.3-rc2. These had been soaking in a branch targeting the merge window, but missed due to a regression hunt. This fixed up version has otherwise been in -next this past week with no reported issues. In order to gain confidence in the locking changes the pull also includes a debug / instrumentation patch to enable lockdep coverage for libnvdimm subsystem operations that depend on the device_lock for exclusion. As mentioned in the changelog it is a hack, but it works and documents the locking expectations of the sub-system in a way that others can use lockdep to verify. The driver core touches got an ack from Greg. Summary: - Fix duplicate device_unregister() calls (multiple threads competing to do unregister work when scheduling device removal from a sysfs attribute of the self-same device). - Fix badblocks registration order bug. Ensure region badblocks are initialized in advance of namespace registration. - Fix a deadlock between the bus lock and probe operations. - Export device-core infrastructure to coordinate async operations via the device ->dead state. - Add device-core infrastructure to validate device_lock() usage with lockdep" * tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: driver-core, libnvdimm: Let device subsystems add local lockdep coverage libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl() libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant libnvdimm/region: Register badblocks before namespaces libnvdimm/bus: Prevent duplicate device_unregister() calls drivers/base: Introduce kill_device()
2019-07-18driver-core, libnvdimm: Let device subsystems add local lockdep coverageDan Williams
For good reason, the standard device_lock() is marked lockdep_set_novalidate_class() because there is simply no sane way to describe the myriad ways the device_lock() ordered with other locks. However, that leaves subsystems that know their own local device_lock() ordering rules to find lock ordering mistakes manually. Instead, introduce an optional / additional lockdep-enabled lock that a subsystem can acquire in all the same paths that the device_lock() is acquired. A conversion of the NFIT driver and NVDIMM subsystem to a lockdep-validate device_lock() scheme is included. The debug_nvdimm_lock() implementation implements the correct lock-class and stacking order for the libnvdimm device topology hierarchy. Yes, this is a hack, but hopefully it is a useful hack for other subsystems device_lock() debug sessions. Quoting Greg: "Yeah, it feels a bit hacky but it's really up to a subsystem to mess up using it as much as anything else, so user beware :) I don't object to it if it makes things easier for you to debug." Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
2019-07-18libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlockDan Williams
A multithreaded namespace creation/destruction stress test currently deadlocks with the following lockup signature: INFO: task ndctl:2924 blocked for more than 122 seconds. Tainted: G OE 5.2.0-rc4+ #3382 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. ndctl D 0 2924 1176 0x00000000 Call Trace: ? __schedule+0x27e/0x780 schedule+0x30/0xb0 wait_nvdimm_bus_probe_idle+0x8a/0xd0 [libnvdimm] ? finish_wait+0x80/0x80 uuid_store+0xe6/0x2e0 [libnvdimm] kernfs_fop_write+0xf0/0x1a0 vfs_write+0xb7/0x1b0 ksys_write+0x5c/0xd0 do_syscall_64+0x60/0x240 INFO: task ndctl:2923 blocked for more than 122 seconds. Tainted: G OE 5.2.0-rc4+ #3382 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. ndctl D 0 2923 1175 0x00000000 Call Trace: ? __schedule+0x27e/0x780 ? __mutex_lock+0x489/0x910 schedule+0x30/0xb0 schedule_preempt_disabled+0x11/0x20 __mutex_lock+0x48e/0x910 ? nvdimm_namespace_common_probe+0x95/0x4d0 [libnvdimm] ? __lock_acquire+0x23f/0x1710 ? nvdimm_namespace_common_probe+0x95/0x4d0 [libnvdimm] nvdimm_namespace_common_probe+0x95/0x4d0 [libnvdimm] __dax_pmem_probe+0x5e/0x210 [dax_pmem_core] ? nvdimm_bus_probe+0x1d0/0x2c0 [libnvdimm] dax_pmem_probe+0xc/0x20 [dax_pmem] nvdimm_bus_probe+0x90/0x2c0 [libnvdimm] really_probe+0xef/0x390 driver_probe_device+0xb4/0x100 In this sequence an 'nd_dax' device is being probed and trying to take the lock on its backing namespace to validate that the 'nd_dax' device indeed has exclusive access to the backing namespace. Meanwhile, another thread is trying to update the uuid property of that same backing namespace. So one thread is in the probe path trying to acquire the lock, and the other thread has acquired the lock and tries to flush the probe path. Fix this deadlock by not holding the namespace device_lock over the wait_nvdimm_bus_probe_idle() synchronization step. In turn this requires the device_lock to be held on entry to wait_nvdimm_bus_probe_idle() and subsequently dropped internally to wait_nvdimm_bus_probe_idle(). Cc: <stable@vger.kernel.org> Fixes: bf9bccc14c05 ("libnvdimm: pmem label sets and namespace instantiation") Cc: Vishal Verma <vishal.l.verma@intel.com> Tested-by: Jane Chu <jane.chu@oracle.com> Link: https://lore.kernel.org/r/156341210094.292348.2384694131126767789.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-05libnvdimm: add dax_dev sync flagPankaj Gupta
This patch adds 'DAXDEV_SYNC' flag which is set for nd_region doing synchronous flush. This later is used to disable MAP_SYNC functionality for ext4 & xfs filesystem for devices don't support synchronous flush. Signed-off-by: Pankaj Gupta <pagupta@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-05libnvdimm: nd_region flush callback supportPankaj Gupta
This patch adds functionality to perform flush from guest to host over VIRTIO. We are registering a callback based on 'nd_region' type. virtio_pmem driver requires this special flush function. For rest of the region types we are registering existing flush function. Report error returned by host fsync failure to userspace. Signed-off-by: Pankaj Gupta <pagupta@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>