kernel/linux.git/drivers/nvdimm, branch v4.19.112

libnvdimm/btt: fix variable 'rc' set but not used

2020-01-04T18:13:00+00:00

[ Upstream commit 4e24e37d5313edca8b4ab86f240c046c731e28d6 ] drivers/nvdimm/btt.c: In function 'btt_read_pg': drivers/nvdimm/btt.c:1264:8: warning: variable 'rc' set but not used [-Wunused-but-set-variable] int rc; ^~ Add a ratelimited message in case a storm of errors is encountered. Fixes: d9b83c756953 ("libnvdimm, btt: rework error clearing") Signed-off-by: Qian Cai Reviewed-by: Vishal Verma Link: https://lore.kernel.org/r/1572530719-32161-1-git-send-email-cai@lca.pw Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

libnvdimm/region: Initialize bad block for volatile namespaces

2019-10-11T16:21:20+00:00

[ Upstream commit c42adf87e4e7ed77f6ffe288dc90f980d07d68df ] 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 Link: https://lore.kernel.org/r/20190919083355.26340-1-aneesh.kumar@linux.ibm.com Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock

2019-08-09T15:52:28+00:00

commit ca6bf264f6d856f959c4239cda1047b587745c67 upstream. 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: Fixes: bf9bccc14c05 ("libnvdimm: pmem label sets and namespace instantiation") Cc: Vishal Verma Tested-by: Jane Chu Link: https://lore.kernel.org/r/156341210094.292348.2384694131126767789.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant

2019-08-09T15:52:28+00:00

commit 6de5d06e657acdbcf9637dac37916a4a5309e0f4 upstream. In preparation for not holding a lock over the execution of nd_ioctl(), update the implementation to allow multiple threads to be attempting ioctls at the same time. The bus lock still prevents multiple in-flight ->ndctl() invocations from corrupting each other's state, but static global staging buffers are moved to the heap. Reported-by: Vishal Verma Reviewed-by: Vishal Verma Tested-by: Vishal Verma Link: https://lore.kernel.org/r/156341208947.292348.10560140326807607481.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

libnvdimm/region: Register badblocks before namespaces

2019-08-09T15:52:28+00:00

commit 700cd033a82d466ad8f9615f9985525e45f8960a upstream. Namespace activation expects to be able to reference region badblocks. The following warning sometimes triggers when asynchronous namespace activation races in front of the completion of namespace probing. Move all possible namespace probing after region badblocks initialization. Otherwise, lockdep sometimes catches the uninitialized state of the badblocks seqlock with stack trace signatures like: INFO: trying to register non-static key. pmem2: detected capacity change from 0 to 136365211648 the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 9 PID: 358 Comm: kworker/u80:5 Tainted: G OE 5.2.0-rc4+ #3382 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Workqueue: events_unbound async_run_entry_fn Call Trace: dump_stack+0x85/0xc0 pmem1.12: detected capacity change from 0 to 8589934592 register_lock_class+0x56a/0x570 ? check_object+0x140/0x270 __lock_acquire+0x80/0x1710 ? __mutex_lock+0x39d/0x910 lock_acquire+0x9e/0x180 ? nd_pfn_validate+0x28f/0x440 [libnvdimm] badblocks_check+0x93/0x1f0 ? nd_pfn_validate+0x28f/0x440 [libnvdimm] nd_pfn_validate+0x28f/0x440 [libnvdimm] ? lockdep_hardirqs_on+0xf0/0x180 nd_dax_probe+0x9a/0x120 [libnvdimm] nd_pmem_probe+0x6d/0x180 [nd_pmem] nvdimm_bus_probe+0x90/0x2c0 [libnvdimm] Fixes: 48af2f7e52f4 ("libnvdimm, pfn: during init, clear errors...") Cc: Cc: Vishal Verma Reviewed-by: Vishal Verma Link: https://lore.kernel.org/r/156341208365.292348.1547528796026249120.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

libnvdimm/bus: Prevent duplicate device_unregister() calls

2019-08-09T15:52:28+00:00

commit 8aac0e2338916e273ccbd438a2b7a1e8c61749f5 upstream. A multithreaded namespace creation/destruction stress test currently fails with signatures like the following: sysfs group 'power' not found for kobject 'dax1.1' RIP: 0010:sysfs_remove_group+0x76/0x80 Call Trace: device_del+0x73/0x370 device_unregister+0x16/0x50 nd_async_device_unregister+0x1e/0x30 [libnvdimm] async_run_entry_fn+0x39/0x160 process_one_work+0x23c/0x5e0 worker_thread+0x3c/0x390 BUG: kernel NULL pointer dereference, address: 0000000000000020 RIP: 0010:klist_put+0x1b/0x6c Call Trace: klist_del+0xe/0x10 device_del+0x8a/0x2c9 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 device_unregister+0x44/0x4f nd_async_device_unregister+0x22/0x2d [libnvdimm] async_run_entry_fn+0x47/0x15a process_one_work+0x1a2/0x2eb worker_thread+0x1b8/0x26e Use the kill_device() helper to atomically resolve the race of multiple threads issuing kill, device_unregister(), requests. Reported-by: Jane Chu Reported-by: Erwin Tsaur Fixes: 4d88a97aa9e8 ("libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver...") Cc: Link: https://github.com/pmem/ndctl/issues/96 Tested-by: Tested-by: Jane Chu Link: https://lore.kernel.org/r/156341207846.292348.10435719262819764054.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl()

2019-07-31T05:27:11+00:00

commit b70d31d054ee3a6fc1034b9d7fc0ae1e481aa018 upstream. In preparation for fixing a deadlock between wait_for_bus_probe_idle() and the nvdimm_bus_list_mutex arrange for __nd_ioctl() without nvdimm_bus_list_mutex held. This also unifies the 'dimm' and 'bus' level ioctls into a common nd_ioctl() preamble implementation. Marked for -stable as it is a pre-requisite for a follow-on fix. Cc: Fixes: bf9bccc14c05 ("libnvdimm: pmem label sets and namespace instantiation") Cc: Vishal Verma Tested-by: Jane Chu Link: https://lore.kernel.org/r/156341209518.292348.7183897251740665198.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields

2019-07-26T07:14:27+00:00

commit 7e3e888dfc138089f4c15a81b418e88f0978f744 upstream. At namespace creation time there is the potential for the "expected to be zero" fields of a 'pfn' info-block to be filled with indeterminate data. While the kernel buffer is zeroed on allocation it is immediately overwritten by nd_pfn_validate() filling it with the current contents of the on-media info-block location. For fields like, 'flags' and the 'padding' it potentially means that future implementations can not rely on those fields being zero. In preparation to stop using the 'start_pad' and 'end_trunc' fields for section alignment, arrange for fields that are not explicitly initialized to be guaranteed zero. Bump the minor version to indicate it is safe to assume the 'padding' and 'flags' are zero. Otherwise, this corruption is expected to benign since all other critical fields are explicitly initialized. Note The cc: stable is about spreading this new policy to as many kernels as possible not fixing an issue in those kernels. It is not until the change titled "libnvdimm/pfn: Stop padding pmem namespaces to section alignment" where this improper initialization becomes a problem. So if someone decides to backport "libnvdimm/pfn: Stop padding pmem namespaces to section alignment" (which is not tagged for stable), make sure this pre-requisite is flagged. Link: http://lkml.kernel.org/r/156092356065.979959.6681003754765958296.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 32ab0a3f5170 ("libnvdimm, pmem: 'struct page' for pmem") Signed-off-by: Dan Williams Tested-by: Aneesh Kumar K.V [ppc64] Cc: Cc: David Hildenbrand Cc: Jane Chu Cc: Jeff Moyer Cc: Jérôme Glisse Cc: Jonathan Corbet Cc: Logan Gunthorpe Cc: Michal Hocko Cc: Mike Rapoport Cc: Oscar Salvador Cc: Pavel Tatashin Cc: Toshi Kani Cc: Vlastimil Babka Cc: Wei Yang Cc: Jason Gunthorpe Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

libnvdimm: Fix compilation warnings with W=1

2019-06-19T06:18:03+00:00

[ Upstream commit c01dafad77fea8d64c4fdca0a6031c980842ad65 ] Several places (dimm_devs.c, core.c etc) include label.h but only label.c uses NSINDEX_SIGNATURE, so move its definition to label.c instead. In file included from drivers/nvdimm/dimm_devs.c:23: drivers/nvdimm/label.h:41:19: warning: 'NSINDEX_SIGNATURE' defined but not used [-Wunused-const-variable=] Also, some places abuse "/**" which is only reserved for the kernel-doc. drivers/nvdimm/bus.c:648: warning: cannot understand function prototype: 'struct attribute_group nd_device_attribute_group = ' drivers/nvdimm/bus.c:677: warning: cannot understand function prototype: 'struct attribute_group nd_numa_attribute_group = ' Those are just some member assignments for the "struct attribute_group" instances and it can't be expressed in the kernel-doc. Reviewed-by: Vishal Verma Signed-off-by: Qian Cai Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

libnvdimm/pmem: Bypass CONFIG_HARDENED_USERCOPY overhead

2019-05-31T13:46:01+00:00

commit 52f476a323f9efc959be1c890d0cdcf12e1582e0 upstream. Jeff discovered that performance improves from ~375K iops to ~519K iops on a simple psync-write fio workload when moving the location of 'struct page' from the default PMEM location to DRAM. This result is surprising because the expectation is that 'struct page' for dax is only needed for third party references to dax mappings. For example, a dax-mapped buffer passed to another system call for direct-I/O requires 'struct page' for sending the request down the driver stack and pinning the page. There is no usage of 'struct page' for first party access to a file via read(2)/write(2) and friends. However, this "no page needed" expectation is violated by CONFIG_HARDENED_USERCOPY and the check_copy_size() performed in copy_from_iter_full_nocache() and copy_to_iter_mcsafe(). The check_heap_object() helper routine assumes the buffer is backed by a slab allocator (DRAM) page and applies some checks. Those checks are invalid, dax pages do not originate from the slab, and redundant, dax_iomap_actor() has already validated that the I/O is within bounds. Specifically that routine validates that the logical file offset is within bounds of the file, then it does a sector-to-pfn translation which validates that the physical mapping is within bounds of the block device. Bypass additional hardened usercopy overhead and call the 'no check' versions of the copy_{to,from}_iter operations directly. Fixes: 0aed55af8834 ("x86, uaccess: introduce copy_from_iter_flushcache...") Cc: Cc: Jeff Moyer Cc: Ingo Molnar Cc: Christoph Hellwig Cc: Al Viro Cc: Thomas Gleixner Cc: Matthew Wilcox Reported-and-tested-by: Jeff Smits Acked-by: Kees Cook Acked-by: Jan Kara Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman