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* device-dax: fix sysfs duplicate warningsDan Williams2017-07-181-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix warnings of the form... WARNING: CPU: 10 PID: 4983 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80 sysfs: cannot create duplicate filename '/class/dax/dax12.0' Call Trace: dump_stack+0x63/0x86 __warn+0xcb/0xf0 warn_slowpath_fmt+0x5a/0x80 ? kernfs_path_from_node+0x4f/0x60 sysfs_warn_dup+0x62/0x80 sysfs_do_create_link_sd.isra.2+0x97/0xb0 sysfs_create_link+0x25/0x40 device_add+0x266/0x630 devm_create_dax_dev+0x2cf/0x340 [dax] dax_pmem_probe+0x1f5/0x26e [dax_pmem] nvdimm_bus_probe+0x71/0x120 ...by reusing the namespace id for the device-dax instance name. Now that we have decided that there will never by more than one device-dax instance per libnvdimm-namespace parent device [1], we can directly reuse the namepace ids. There are some possible follow-on cleanups, but those are saved for a later patch to simplify the -stable backport. [1]: https://lists.01.org/pipermail/linux-nvdimm/2016-December/008266.html Fixes: 98a29c39dc68 ("libnvdimm, namespace: allow creation of multiple pmem...") Cc: Jeff Moyer <jmoyer@redhat.com> Cc: <stable@vger.kernel.org> Reported-by: Dariusz Dokupil <dariusz.dokupil@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge tag 'libnvdimm-for-4.12' of ↵Linus Torvalds2017-05-051-5/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this has been in multiple -next releases. There were a few late breaking fixes and small features that got added in the last couple days, but the whole set has received a build success notification from the kbuild robot. Change summary: - Region media error reporting: A libnvdimm region device is the parent to one or more namespaces. To date, media errors have been reported via the "badblocks" attribute attached to pmem block devices for namespaces in "raw" or "memory" mode. Given that namespaces can be in "device-dax" or "btt-sector" mode this new interface reports media errors generically, i.e. independent of namespace modes or state. This subsequently allows userspace tooling to craft "ACPI 6.1 Section 9.20.7.6 Function Index 4 - Clear Uncorrectable Error" requests and submit them via the ioctl path for NVDIMM root bus devices. - Introduce 'struct dax_device' and 'struct dax_operations': Prompted by a request from Linus and feedback from Christoph this allows for dax capable drivers to publish their own custom dax operations. This fixes the broken assumption that all dax operations are related to a persistent memory device, and makes it easier for other architectures and platforms to add customized persistent memory support. - 'libnvdimm' core updates: A new "deep_flush" sysfs attribute is available for storage appliance applications to manually trigger memory controllers to drain write-pending buffers that would otherwise be flushed automatically by the platform ADR (asynchronous-DRAM-refresh) mechanism at a power loss event. Support for "locked" DIMMs is included to prevent namespaces from surfacing when the namespace label data area is locked. Finally, fixes for various reported deadlocks and crashes, also tagged for -stable. - ACPI / nfit driver updates: General updates of the nfit driver to add DSM command overrides, ACPI 6.1 health state flags support, DSM payload debug available by default, and various fixes. Acknowledgements that came after the branch was pushed: - commmit 565851c972b5 "device-dax: fix sysfs attribute deadlock": Tested-by: Yi Zhang <yizhan@redhat.com> - commit 23f498448362 "libnvdimm: rework region badblocks clearing" Tested-by: Toshi Kani <toshi.kani@hpe.com>" * tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (52 commits) libnvdimm, pfn: fix 'npfns' vs section alignment libnvdimm: handle locked label storage areas libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED brd: fix uninitialized use of brd->dax_dev block, dax: use correct format string in bdev_dax_supported device-dax: fix sysfs attribute deadlock libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking" libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering libnvdimm: rework region badblocks clearing acpi, nfit: kill ACPI_NFIT_DEBUG libnvdimm: fix clear length of nvdimm_forget_poison() libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify libnvdimm, region: sysfs trigger for nvdimm_flush() libnvdimm: fix phys_addr for nvdimm_clear_poison x86, dax, pmem: remove indirection around memcpy_from_pmem() block: remove block_device_operations ->direct_access() block, dax: convert bdev_dax_supported() to dax_direct_access() filesystem-dax: convert to dax_direct_access() Revert "block: use DAX for partition table reads" ext2, ext4, xfs: retrieve dax_device for iomap operations ...
| * dax: refactor dax-fs into a generic provider of 'struct dax_device' instancesDan Williams2017-04-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want dax capable drivers to be able to publish a set of dax operations [1]. However, we do not want to further abuse block_devices to advertise these operations. Instead we will attach these operations to a dax device and add a lookup mechanism to go from block device path to a dax device. A dax capable driver like pmem or brd is responsible for registering a dax device, alongside a block device, and then a dax capable filesystem is responsible for retrieving the dax device by path name if it wants to call dax_operations. For now, we refactor the dax pseudo-fs to be a generic facility, rather than an implementation detail, of the device-dax use case. Where a "dax device" is just an inode + dax infrastructure, and "Device DAX" is a mapping service layered on top of that base 'struct dax_device'. "Filesystem DAX" is then a mapping service that layers a filesystem on top of that same base device. Filesystem DAX is associated with a block_device for now, but perhaps directly to a dax device in the future, or for new pmem-only filesystems. [1]: https://lkml.org/lkml/2017/1/19/880 Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * device-dax: rename 'dax_dev' to 'dev_dax'Dan Williams2017-04-121-4/+4
| | | | | | | | | | | | | | | | | | | | In preparation for introducing a struct dax_device type to the kernel global type namespace, rename dax_dev to dev_dax. A 'dax_device' instance will be a generic device-driver object for any provider of dax functionality. A 'dev_dax' object is a device-dax-driver local / internal instance. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | mm, zone_device: Replace {get, put}_zone_device_page() with a single ↵Dan Williams2017-05-011-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | reference to fix pmem crash The x86 conversion to the generic GUP code included a small change which causes crashes and data corruption in the pmem code - not good. The root cause is that the /dev/pmem driver code implicitly relies on the x86 get_user_pages() implementation doing a get_page() on the page refcount, because get_page() does a get_zone_device_page() which properly refcounts pmem's separate page struct arrays that are not present in the regular page struct structures. (The pmem driver does this because it can cover huge memory areas.) But the x86 conversion to the generic GUP code changed the get_page() to page_cache_get_speculative() which is faster but doesn't do the get_zone_device_page() call the pmem code relies on. One way to solve the regression would be to change the generic GUP code to use get_page(), but that would slow things down a bit and punish other generic-GUP using architectures for an x86-ism they did not care about. (Arguably the pmem driver was probably not working reliably for them: but nvdimm is an Intel feature, so non-x86 exposure is probably still limited.) So restructure the pmem code's interface with the MM instead: get rid of the get/put_zone_device_page() distinction, integrate put_zone_device_page() into __put_page() and and restructure the pmem completion-wait and teardown machinery: Kirill points out that the calls to {get,put}_dev_pagemap() can be removed from the mm fast path if we take a single get_dev_pagemap() reference to signify that the page is alive and use the final put of the page to drop that reference. This does require some care to make sure that any waits for the percpu_ref to drop to zero occur *after* devm_memremap_page_release(), since it now maintains its own elevated reference. This speeds up things while also making the pmem refcounting more robust going forward. Suggested-by: Kirill Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Kirill Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/149339998297.24933.1129582806028305912.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'for-4.10/libnvdimm' into libnvdimm-for-nextDan Williams2016-12-171-1/+2
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| * libnvdimm: use consistent naming for request_mem_region()Dan Williams2016-11-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here is an example /proc/iomem listing for a system with 2 namespaces, one in "sector" mode and one in "memory" mode: 1fc000000-2fbffffff : Persistent Memory (legacy) 1fc000000-2fbffffff : namespace1.0 340000000-34fffffff : Persistent Memory 340000000-34fffffff : btt0.1 Here is the corresponding ndctl listing: # ndctl list [ { "dev":"namespace1.0", "mode":"memory", "size":4294967296, "blockdev":"pmem1" }, { "dev":"namespace0.0", "mode":"sector", "size":267091968, "uuid":"f7594f86-badb-4592-875f-ded577da2eaf", "sector_size":4096, "blockdev":"pmem0s" } ] Notice that the ndctl listing is purely in terms of namespace devices, while the iomem listing leaks the internal "btt0.1" implementation detail. Given that ndctl requires the namespace device name to change the mode, for example: # ndctl create-namespace --reconfig=namespace0.0 --mode=raw --force ...use the namespace name in the iomem listing to keep the claiming device name consistent across different mode settings. Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | device-dax: check devm_nsio_enable() return valueDan Williams2016-10-281-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the dax_pmem driver is passed a resource that is already busy the driver probe attempt should fail with a message like the following: dax_pmem dax0.1: could not reserve region [mem 0x100000000-0x11fffffff] However, if we do not catch the error we crash for the obvious reason of accessing memory that is not mapped. BUG: unable to handle kernel paging request at ffffc90020001000 IP: [<ffffffff81496712>] __memcpy+0x12/0x20 [..] Call Trace: [<ffffffff815c4960>] ? nsio_rw_bytes+0x60/0x180 [<ffffffff815c6045>] nd_pfn_validate+0x75/0x320 [<ffffffff815c63a9>] nvdimm_setup_pfn+0xb9/0x5d0 [<ffffffff815c48ef>] ? devm_nsio_enable+0xff/0x110 [<ffffffff815cb699>] dax_pmem_probe+0x59/0x260 Cc: <stable@vger.kernel.org> Fixes: ab68f2622136 ("/dev/dax, pmem: direct access to persistent memory") Reported-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | device-dax: fix percpu_ref_exit orderingDan Williams2016-10-271-1/+1
|/ | | | | | | | | | | | | | | | | | | | | We need to wait until the percpu_ref is released before exit. Otherwise, we sometimes lose the race and trigger this new warning that was added in v4.9 (commit a67823c1ed10 "percpu-refcount: init ->confirm_switch member properly"): WARNING: CPU: 0 PID: 3629 at lib/percpu-refcount.c:107 percpu_ref_exit+0x51/0x60 [..] Call Trace: [<ffffffff814bf093>] dump_stack+0x85/0xc2 [<ffffffff810b15db>] __warn+0xcb/0xf0 [<ffffffff810b170d>] warn_slowpath_null+0x1d/0x20 [<ffffffff814d70c1>] percpu_ref_exit+0x51/0x60 [<ffffffffa005706a>] dax_pmem_percpu_exit+0x1a/0x50 [dax_pmem] [<ffffffff81615f1f>] devm_action_release+0xf/0x20 Cc: <stable@vger.kernel.org> Fixes: ab68f2622136 ("/dev/dax, pmem: direct access to persistent memory") Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge branch 'for-4.9/dax' into libnvdimm-for-nextDan Williams2016-10-071-3/+4
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| * dax: convert devm_create_dax_dev to PTR_ERRDan Williams2016-10-071-2/+3
| | | | | | | | | | | | | | For sub-division support we need access to the dax_dev created by devm_create_dax_dev(). Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * dax: cleanup needlessly global symbol warningsDan Williams2016-08-231-1/+1
| | | | | | | | | | | | | | | | | | drivers/dax/dax.c:75:6: warning: symbol 'dax_region_put' was not declared. drivers/dax/dax.c:95:19: warning: symbol 'alloc_dax_region' was not declared. drivers/dax/dax.c:173:5: warning: symbol 'devm_create_dax_dev' was not declared. drivers/dax/pmem.c:27:17: warning: symbol 'to_dax_pmem' was not declared. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | dax: fix device-dax region baseDan Williams2016-08-261-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The data offset for a dax region needs to account for a reservation in the resource range. Otherwise, device-dax is allowing mappings directly into the memmap or device-info-block area with crash signatures like the following: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: get_zone_device_page+0x11/0x30 Call Trace: follow_devmap_pmd+0x298/0x2c0 follow_page_mask+0x275/0x530 __get_user_pages+0xe3/0x750 __gfn_to_pfn_memslot+0x1b2/0x450 [kvm] tdp_page_fault+0x130/0x280 [kvm] kvm_mmu_page_fault+0x5f/0xf0 [kvm] handle_ept_violation+0x94/0x180 [kvm_intel] vmx_handle_exit+0x1d3/0x1440 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x81d/0x16a0 [kvm] kvm_vcpu_ioctl+0x33c/0x620 [kvm] do_vfs_ioctl+0xa2/0x5d0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x1a/0xa4 Fixes: ab68f2622136 ("/dev/dax, pmem: direct access to persistent memory") Link: http://lkml.kernel.org/r/147205536732.1606.8994275381938837346.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Abhilash Kumar Mulumudi <m.abhilash-kumar@hpe.com> Reported-by: Toshi Kani <toshi.kani@hpe.com> Tested-by: Toshi Kani <toshi.kani@hpe.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dax: use devm_add_action_or_reset()Sajjan, Vikas C2016-07-061-8/+6
| | | | | | | | | | | | If devm_add_action() fails, we are explicitly calling the cleanup to free the resources allocated. Use the helper devm_add_action_or_reset() and return directly in case of error, since the cleanup function has been already called by the helper if there was any error. Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Vikas C Sajjan <vikas.cha.sajjan@hpe.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* /dev/dax, pmem: direct access to persistent memoryDan Williams2016-05-201-0/+158
Device DAX is the device-centric analogue of Filesystem DAX (CONFIG_FS_DAX). It allows memory ranges to be allocated and mapped without need of an intervening file system. Device DAX is strict, precise and predictable. Specifically this interface: 1/ Guarantees fault granularity with respect to a given page size (pte, pmd, or pud) set at configuration time. 2/ Enforces deterministic behavior by being strict about what fault scenarios are supported. For example, by forcing MADV_DONTFORK semantics and omitting MAP_PRIVATE support device-dax guarantees that a mapping always behaves/performs the same once established. It is the "what you see is what you get" access mechanism to differentiated memory vs filesystem DAX which has filesystem specific implementation semantics. Persistent memory is the first target, but the mechanism is also targeted for exclusive allocations of performance differentiated memory ranges. This commit is limited to the base device driver infrastructure to associate a dax device with pmem range. Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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