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2017-06-09device-dax: fix 'dax' device filesystem inode destruction crashDan Williams1-2/+7
The inode destruction path for the 'dax' device filesystem incorrectly assumes that the inode was initialized through 'alloc_dax()'. However, if someone attempts to directly mount the dax filesystem with 'mount -t dax dax mnt' that will bypass 'alloc_dax()' and the following failure signatures may occur as a result: kill_dax() must be called before final iput() WARNING: CPU: 2 PID: 1188 at drivers/dax/super.c:243 dax_destroy_inode+0x48/0x50 RIP: 0010:dax_destroy_inode+0x48/0x50 Call Trace: destroy_inode+0x3b/0x60 evict+0x139/0x1c0 iput+0x1f9/0x2d0 dentry_unlink_inode+0xc3/0x160 __dentry_kill+0xcf/0x180 ? dput+0x37/0x3b0 dput+0x3a3/0x3b0 do_one_tree+0x36/0x40 shrink_dcache_for_umount+0x2d/0x90 generic_shutdown_super+0x1f/0x120 kill_anon_super+0x12/0x20 deactivate_locked_super+0x43/0x70 deactivate_super+0x4e/0x60 general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC RIP: 0010:kfree+0x6d/0x290 Call Trace: <IRQ> dax_i_callback+0x22/0x60 ? dax_destroy_inode+0x50/0x50 rcu_process_callbacks+0x298/0x740 ida_remove called for id=0 which is not allocated. WARNING: CPU: 0 PID: 0 at lib/idr.c:383 ida_remove+0x110/0x120 [..] Call Trace: <IRQ> ida_simple_remove+0x2b/0x50 ? dax_destroy_inode+0x50/0x50 dax_i_callback+0x3c/0x60 rcu_process_callbacks+0x298/0x740 Add missing initialization of the 'struct dax_device' and inode so that the destruction path does not kfree() or ida_simple_remove() uninitialized data. Fixes: 7b6be8444e0f ("dax: refactor dax-fs into a generic provider of 'struct dax_device' instances") Reported-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-13dax: fix false CONFIG_BLOCK dependencyDan Williams1-0/+2
In the BLOCK=n case the dax core does not need to / must not emit the block-device-dax helpers. Otherwise it leads to compile errors. Cc: Arnd Bergmann <arnd@arndb.de> Reported-by: Fabian Frederick <fabf@skynet.be> Fixes: ef51042472f5 ("block, dax: move 'select DAX' from BLOCK to FS_DAX") Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-12Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds2-14/+74
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "Incremental fixes and a small feature addition on top of the main libnvdimm 4.12 pull request: - Geert noticed that tinyconfig was bloated by BLOCK selecting DAX. The size regression is fixed by moving all dax helpers into the dax-core and only specifying "select DAX" for FS_DAX and dax-capable drivers. He also asked for clarification of the NR_DEV_DAX config option which, on closer look, does not need to be a config option at all. Mike also throws in a DEV_DAX_PMEM fixup for good measure. - Ben's attention to detail on -stable patch submissions caught a case where the recent fixes to arch_copy_from_iter_pmem() missed a condition where we strand dirty data in the cache. This is tagged for -stable and will also be included in the rework of the pmem api to a proposed {memcpy,copy_user}_flushcache() interface for 4.13. - Vishal adds a feature that missed the initial pull due to pending review feedback. It allows the kernel to clear media errors when initializing a BTT (atomic sector update driver) instance on a pmem namespace. - Ross noticed that the dax_device + dax_operations conversion broke __dax_zero_page_range(). The nvdimm unit tests fail to check this path, but xfstests immediately trips over it. No excuse for missing this before submitting the 4.12 pull request. These all pass the nvdimm unit tests and an xfstests spot check. The set has received a build success notification from the kbuild robot" * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: filesystem-dax: fix broken __dax_zero_page_range() conversion libnvdimm, btt: ensure that initializing metadata clears poison libnvdimm: add an atomic vs process context flag to rw_bytes x86, pmem: Fix cache flushing for iovec write < 8 bytes device-dax: kill NR_DEV_DAX block, dax: move "select DAX" from BLOCK to FS_DAX device-dax: Tell kbuild DEV_DAX_PMEM depends on DEV_DAX
2017-05-09device-dax: kill NR_DEV_DAXDan Williams2-13/+3
There is no point to ask how many device-dax instances the kernel should support. Since we are already using a dynamic major number, just allow the max number of minors by default and be done. This also fixes the fact that the proposed max for the NR_DEV_DAX range was larger than what could be supported by alloc_chrdev_region(). Fixes: ba09c01d2fa8 ("dax: convert to the cdev api") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-08block, dax: move "select DAX" from BLOCK to FS_DAXDan Williams1-0/+70
For configurations that do not enable DAX filesystems or drivers, do not require the DAX core to be built. Given that the 'direct_access' method has been removed from 'block_device_operations', we can also go ahead and remove the block-related dax helper functions from fs/block_dev.c to drivers/dax/super.c. This keeps dax details out of the block layer and lets the DAX core be built as a module in the FS_DAX=n case. Filesystems need to include dax.h to call bdev_dax_supported(). Cc: linux-xfs@vger.kernel.org Cc: Jens Axboe <axboe@kernel.dk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-08device-dax: Tell kbuild DEV_DAX_PMEM depends on DEV_DAXMike Galbraith1-1/+1
ERROR: "devm_create_dev_dax" [drivers/dax/dax_pmem.ko] undefined! ERROR: "alloc_dax_region" [drivers/dax/dax_pmem.ko] undefined! ERROR: "dax_region_put" [drivers/dax/dax_pmem.ko] undefined! Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-05Merge tag 'libnvdimm-for-4.12' of ↵Linus Torvalds8-371/+677
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 ...
2017-05-04Merge branch 'for-4.12/dax' into libnvdimm-for-nextDan Williams8-319/+619
2017-05-04Merge tag 'char-misc-4.12-rc1' of ↵Linus Torvalds1-17/+16
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the big set of new char/misc driver drivers and features for 4.12-rc1. There's lots of new drivers added this time around, new firmware drivers from Google, more auxdisplay drivers, extcon drivers, fpga drivers, and a bunch of other driver updates. Nothing major, except if you happen to have the hardware for these drivers, and then you will be happy :) All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (136 commits) firmware: google memconsole: Fix return value check in platform_memconsole_init() firmware: Google VPD: Fix return value check in vpd_platform_init() goldfish_pipe: fix build warning about using too much stack. goldfish_pipe: An implementation of more parallel pipe fpga fr br: update supported version numbers fpga: region: release FPGA region reference in error path fpga altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge_probe() mei: drop the TODO from samples firmware: Google VPD sysfs driver firmware: Google VPD: import lib_vpd source files misc: lkdtm: Add volatile to intentional NULL pointer reference eeprom: idt_89hpesx: Add OF device ID table misc: ds1682: Add OF device ID table misc: tsl2550: Add OF device ID table w1: Remove unneeded use of assert() and remove w1_log.h w1: Use kernel common min() implementation uio_mf624: Align memory regions to page size and set correct offsets uio_mf624: Refactor memory info initialization uio: Allow handling of non page-aligned memory regions hangcheck-timer: Fix typo in comment ...
2017-05-01Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "The main x86 MM changes in this cycle were: - continued native kernel PCID support preparation patches to the TLB flushing code (Andy Lutomirski) - various fixes related to 32-bit compat syscall returning address over 4Gb in applications, launched from 64-bit binaries - motivated by C/R frameworks such as Virtuozzo. (Dmitry Safonov) - continued Intel 5-level paging enablement: in particular the conversion of x86 GUP to the generic GUP code. (Kirill A. Shutemov) - x86/mpx ABI corner case fixes/enhancements (Joerg Roedel) - ... plus misc updates, fixes and cleanups" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (62 commits) mm, zone_device: Replace {get, put}_zone_device_page() with a single reference to fix pmem crash x86/mm: Fix flush_tlb_page() on Xen x86/mm: Make flush_tlb_mm_range() more predictable x86/mm: Remove flush_tlb() and flush_tlb_current_task() x86/vm86/32: Switch to flush_tlb_mm_range() in mark_screen_rdonly() x86/mm/64: Fix crash in remove_pagetable() Revert "x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation" x86/boot/e820: Remove a redundant self assignment x86/mm: Fix dump pagetables for 4 levels of page tables x86/mpx, selftests: Only check bounds-vs-shadow when we keep shadow x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space Revert "x86/mm/numa: Remove numa_nodemask_from_meminfo()" x86/espfix: Add support for 5-level paging x86/kasan: Extend KASAN to support 5-level paging x86/mm: Add basic defines/helpers for CONFIG_X86_5LEVEL=y x86/paravirt: Add 5-level support to the paravirt code x86/mm: Define virtual memory map for 5-level paging x86/asm: Remove __VIRTUAL_MASK_SHIFT==47 assert x86/boot: Detect 5-level paging support x86/mm/numa: Remove numa_nodemask_from_meminfo() ...
2017-05-01device-dax: fix sysfs attribute deadlockDan Williams1-28/+12
Usage of device_lock() for dax_region attributes is unnecessary and deadlock prone. It's unnecessary because the order of registration / un-registration guarantees that drvdata is always valid. It's deadlock prone because it sets up this situation: ndctl D 0 2170 2082 0x00000000 Call Trace: __schedule+0x31f/0x980 schedule+0x3d/0x90 schedule_preempt_disabled+0x15/0x20 __mutex_lock+0x402/0x980 ? __mutex_lock+0x158/0x980 ? align_show+0x2b/0x80 [dax] ? kernfs_seq_start+0x2f/0x90 mutex_lock_nested+0x1b/0x20 align_show+0x2b/0x80 [dax] dev_attr_show+0x20/0x50 ndctl D 0 2186 2079 0x00000000 Call Trace: __schedule+0x31f/0x980 schedule+0x3d/0x90 __kernfs_remove+0x1f6/0x340 ? kernfs_remove_by_name_ns+0x45/0xa0 ? remove_wait_queue+0x70/0x70 kernfs_remove_by_name_ns+0x45/0xa0 remove_files.isra.1+0x35/0x70 sysfs_remove_group+0x44/0x90 sysfs_remove_groups+0x2e/0x50 dax_region_unregister+0x25/0x40 [dax] devm_action_release+0xf/0x20 release_nodes+0x16d/0x2b0 devres_release_all+0x3c/0x60 device_release_driver_internal+0x17d/0x220 device_release_driver+0x12/0x20 unbind_store+0x112/0x160 ndctl/2170 is trying to acquire the device_lock() to read an attribute, and ndctl/2186 is holding the device_lock() while trying to drain all active attribute readers. Thanks to Yi Zhang for the reproduction script. Fixes: d7fe1a67f658 ("dax: add region 'id', 'size', and 'align' attributes") Cc: <stable@vger.kernel.org> Reported-by: Yi Zhang <yizhan@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-01mm, zone_device: Replace {get, put}_zone_device_page() with a single ↵Dan Williams1-1/+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>
2017-04-20dax: introduce dax_direct_access()Dan Williams1-0/+39
Replace bdev_direct_access() with dax_direct_access() that uses dax_device and dax_operations instead of a block_device and block_device_operations for dax. Once all consumers of the old api have been converted bdev_direct_access() will be deleted. Given that block device partitioning decisions can cause dax page alignment constraints to be violated this also introduces the bdev_dax_pgoff() helper. It handles calculating a logical pgoff relative to the dax_device and also checks for page alignment. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-19pmem: add dax_operations supportDan Williams1-7/+0
Setup a dax_device to have the same lifetime as the pmem block device and add a ->direct_access() method that is equivalent to pmem_direct_access(). Once fs/dax.c has been converted to use dax_operations the old pmem_direct_access() will be removed. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-19dax: introduce dax_operationsDan Williams3-3/+13
Track a set of dax_operations per dax_device that can be set at alloc_dax() time. These operations will be used to stop the abuse of block_device_operations for communicating dax capabilities to filesystems. It will also be used to replace the "pmem api" and move pmem-specific cache maintenance, and other dax-driver-specific filesystem-dax operations, to dax device methods. In particular this allows us to stop abusing __copy_user_nocache(), via memcpy_to_pmem(), with a driver specific replacement. This is a standalone introduction of the operations. Follow on patches convert each dax-driver and teach fs/dax.c to use ->direct_access() from dax_operations instead of block_device_operations. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-19dax: add a facility to lookup a dax device by 'host' device nameDan Williams3-6/+85
For the current block_device based filesystem-dax path, we need a way for it to lookup the dax_device associated with a block_device. Add a 'host' property of a dax_device that can be used for this purpose. It is a free form string, but for a dax_device associated with a block device it is the bdev name. This is a stop-gap until filesystems are able to mount on a dax-inode directly. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-12dax: refactor dax-fs into a generic provider of 'struct dax_device' instancesDan Williams7-214/+392
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>
2017-04-12device-dax: rename 'dax_dev' to 'dev_dax'Dan Williams3-109/+109
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>
2017-04-12device-dax: improve fault handler debug outputOliver O'Halloran1-7/+10
A couple of minor improvements to the debug output in the fault handlers: a) Print the region alignment and fault size when we sent a SIGBUS because the region alignment is greater than the fault size. b) Fix the message in the PFN_{DEV|MAP} check. c) Additionally print the fault size enum value in the huge fault handler. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-12device-dax: fix dax_dev_huge_fault() unknown fault size handlingPushkar Jambhlekar1-1/+1
The default case for dax_dev_huge_fault() fault size handling mistakenly returns when it should unlock. This is not a problem in practice since the only three possible fault sizes are handled. Going forward, if the core mm adds a new fault size beyond pte, pmd, or pud device-dax should abort VM_FAULT_SIGBUS requests not VM_FAULT_FALLBACK since device-dax guarantees a configured fault granularity for all faults. Signed-off-by: Pushkar Jambhlekar <pushkar.iit@gmail.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-12Merge branch 'for-4.11/libnvdimm' into for-4.12/daxDan Williams2-9/+38
2017-04-12device-dax, tools/testing/nvdimm: enable device-dax with mock resourcesDave Jiang2-46/+67
Provide a replacement pgoff_to_phys() that translates an nfit_test resource (allocated by vmalloc()) to a pfn. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-12device-dax: switch to srcu, fix rcu_read_lock() vs pte allocationDan Williams2-6/+8
The following warning triggers with a new unit test that stresses the device-dax interface. =============================== [ ERR: suspicious RCU usage. ] 4.11.0-rc4+ #1049 Tainted: G O ------------------------------- ./include/linux/rcupdate.h:521 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 2 locks held by fio/9070: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8d0739d7>] __do_page_fault+0x167/0x4f0 #1: (rcu_read_lock){......}, at: [<ffffffffc03fbd02>] dax_dev_huge_fault+0x32/0x620 [dax] Call Trace: dump_stack+0x86/0xc3 lockdep_rcu_suspicious+0xd7/0x110 ___might_sleep+0xac/0x250 __might_sleep+0x4a/0x80 __alloc_pages_nodemask+0x23a/0x360 alloc_pages_current+0xa1/0x1f0 pte_alloc_one+0x17/0x80 __pte_alloc+0x1e/0x120 __get_locked_pte+0x1bf/0x1d0 insert_pfn.isra.70+0x3a/0x100 ? lookup_memtype+0xa6/0xd0 vm_insert_mixed+0x64/0x90 dax_dev_huge_fault+0x520/0x620 [dax] ? dax_dev_huge_fault+0x32/0x620 [dax] dax_dev_fault+0x10/0x20 [dax] __do_fault+0x1e/0x140 __handle_mm_fault+0x9af/0x10d0 handle_mm_fault+0x16d/0x370 ? handle_mm_fault+0x47/0x370 __do_page_fault+0x28c/0x4f0 trace_do_page_fault+0x58/0x2a0 do_async_page_fault+0x1a/0xa0 async_page_fault+0x28/0x30 Inserting a page table entry may trigger an allocation while we are holding a read lock to keep the device instance alive for the duration of the fault. Use srcu for this keep-alive protection. Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap") Cc: <stable@vger.kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-03-27Merge 4.11-rc4 into char-misc-nextGreg Kroah-Hartman1-3/+30
We want the char-misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-21device-dax: utilize new cdev_device_add helper functionLogan Gunthorpe1-13/+5
Replace the open coded registration of the cdev and dev with the new device_add_cdev() helper. The helper replaces a common pattern by taking the proper reference against the parent device and adding both the cdev and the device. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-21input: utilize new cdev_device_add helper functionLogan Gunthorpe0-0/+0
Replace the open coded registration of the cdev and dev with the new device_add_cdev() helper in evdev, joydev and mousedev. The helper replaces a common pattern by taking the proper reference against the parent device and adding both the cdev and the device. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-21device-dax: fix cdev leakDan Williams1-4/+11
If device_add() fails, cleanup the cdev. Otherwise, we leak a kobj_map() with a stale device number. As Jason points out, there is a small possibility that userspace has opened and mapped the device in the time between cdev_add() and the device_add() failure. We need a new kill_dax_dev() helper to invalidate any established mappings. Fixes: ba09c01d2fa8 ("dax: convert to the cdev api") Cc: <stable@vger.kernel.org> Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-10device-dax: fix debug output typoDave Jiang1-3/+3
The debug output for return the return data of pgoff_to_phys() in the fault handlers has 'phys' and 'pgoff' incorrectly swapped. Reported-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-03-10device-dax: fix pud fault fallback handlingDave Jiang1-0/+12
Jeff Moyer reports: With a device dax alignment of 4KB or 2MB, I get sigbus when running the attached fio job file for the current kernel (4.11.0-rc1+). If I specify an alignment of 1GB, it works. I turned on debug output, and saw that it was failing in the huge fault code. dax dax1.0: dax_open dax dax1.0: dax_mmap dax dax1.0: dax_dev_huge_fault: fio: write (0x7f08f0a00000 - dax dax1.0: __dax_dev_pud_fault: phys_to_pgoff(0xffffffffcf60) dax dax1.0: dax_release fio config for reproduce: [global] ioengine=dev-dax direct=0 filename=/dev/dax0.0 bs=2m [write] rw=write [read] stonewall rw=read The driver fails to fallback when taking a fault that is larger than the device alignment, or handling a larger fault when a smaller mapping is already established. While we could support larger mappings for a device with a smaller alignment, that change is too large for the immediate fix. The simplest change is to force fallback until the fault size matches the alignment. Reported-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-03-10device-dax: fix pmd/pte fault fallback handlingDave Jiang1-0/+15
Jeff Moyer reports: With a device dax alignment of 4KB or 2MB, I get sigbus when running the attached fio job file for the current kernel (4.11.0-rc1+). If I specify an alignment of 1GB, it works. I turned on debug output, and saw that it was failing in the huge fault code. dax dax1.0: dax_open dax dax1.0: dax_mmap dax dax1.0: dax_dev_huge_fault: fio: write (0x7f08f0a00000 - dax dax1.0: __dax_dev_pud_fault: phys_to_pgoff(0xffffffffcf60 dax dax1.0: dax_release fio config for reproduce: [global] ioengine=dev-dax direct=0 filename=/dev/dax0.0 bs=2m [write] rw=write [read] stonewall rw=read The driver fails to fallback when taking a fault that is larger than the device alignment, or handling a larger fault when a smaller mapping is already established. While we could support larger mappings for a device with a smaller alignment, that change is too large for the immediate fix. The simplest change is to force fallback until the fault size matches the alignment. Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap") Cc: <stable@vger.kernel.org> Reported-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-03-02sched/headers: Prepare to remove the <linux/magic.h> include from ↵Ingo Molnar1-0/+1
<linux/sched/task_stack.h> Update files that depend on the magic.h inclusion. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-24mm: replace FAULT_FLAG_SIZE with parameter to huge_faultDave Jiang1-6/+12
Since the introduction of FAULT_FLAG_SIZE to the vm_fault flag, it has been somewhat painful with getting the flags set and removed at the correct locations. More than one kernel oops was introduced due to difficulties of getting the placement correctly. Remove the flag values and introduce an input parameter to huge_fault that indicates the size of the page entry. This makes the code easier to trace and should avoid the issues we see with the fault flags where removal of the flag was necessary in the fallback paths. Link: http://lkml.kernel.org/r/148615748258.43180.1690152053774975329.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24dax: support for transparent PUD pages for device DAXDave Jiang1-0/+48
Add transparent huge PUD pages support for device DAX by adding a pud_fault handler. Link: http://lkml.kernel.org/r/148545060002.17912.6765687780007547551.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24mm,fs,dax: change ->pmd_fault to ->huge_faultDave Jiang1-21/+13
Patch series "1G transparent hugepage support for device dax", v2. The following series implements support for 1G trasparent hugepage on x86 for device dax. The bulk of the code was written by Mathew Wilcox a while back supporting transparent 1G hugepage for fs DAX. I have forward ported the relevant bits to 4.10-rc. The current submission has only the necessary code to support device DAX. Comments from Dan Williams: So the motivation and intended user of this functionality mirrors the motivation and users of 1GB page support in hugetlbfs. Given expected capacities of persistent memory devices an in-memory database may want to reduce tlb pressure beyond what they can already achieve with 2MB mappings of a device-dax file. We have customer feedback to that effect as Willy mentioned in his previous version of these patches [1]. [1]: https://lkml.org/lkml/2016/1/31/52 Comments from Nilesh @ Oracle: There are applications which have a process model; and if you assume 10,000 processes attempting to mmap all the 6TB memory available on a server; we are looking at the following: processes : 10,000 memory : 6TB pte @ 4k page size: 8 bytes / 4K of memory * #processes = 6TB / 4k * 8 * 10000 = 1.5GB * 80000 = 120,000GB pmd @ 2M page size: 120,000 / 512 = ~240GB pud @ 1G page size: 240GB / 512 = ~480MB As you can see with 2M pages, this system will use up an exorbitant amount of DRAM to hold the page tables; but the 1G pages finally brings it down to a reasonable level. Memory sizes will keep increasing; so this number will keep increasing. An argument can be made to convert the applications from process model to thread model, but in the real world that may not be always practical. Hopefully this helps explain the use case where this is valuable. This patch (of 3): In preparation for adding the ability to handle PUD pages, convert vm_operations_struct.pmd_fault to vm_operations_struct.huge_fault. The vm_fault structure is extended to include a union of the different page table pointers that may be needed, and three flag bits are reserved to indicate which type of pointer is in the union. [ross.zwisler@linux.intel.com: remove unused function ext4_dax_huge_fault()] Link: http://lkml.kernel.org/r/1485813172-7284-1-git-send-email-ross.zwisler@linux.intel.com [dave.jiang@intel.com: clear PMD or PUD size flags when in fall through path] Link: http://lkml.kernel.org/r/148589842696.5820.16078080610311444794.stgit@djiang5-desk3.ch.intel.com Link: http://lkml.kernel.org/r/148545058784.17912.6353162518188733642.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmfDave Jiang1-6/+6
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to take a vma and vmf parameter when the vma already resides in vmf. Remove the vma parameter to simplify things. [arnd@arndb.de: fix ARM build] Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm, dax: change pmd_fault() to take only vmf parameterDave Jiang1-9/+9
pmd_fault() and related functions really only need the vmf parameter since the additional parameters are all included in the vmf struct. Remove the additional parameter and simplify pmd_fault() and friends. Link: http://lkml.kernel.org/r/1484085142-2297-8-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm, dax: make pmd_fault() and friends be the same as fault()Dave Jiang1-9/+7
Instead of passing in multiple parameters in the pmd_fault() handler, a vmf can be passed in just like a fault() handler. This will simplify code and remove the need for the actual pmd fault handlers to allocate a vmf. Related functions are also modified to do the same. [dave.jiang@intel.com: fix issue with xfs_tests stall when DAX option is off] Link: http://lkml.kernel.org/r/148469861071.195597.3619476895250028518.stgit@djiang5-desk3.ch.intel.com Link: http://lkml.kernel.org/r/1484085142-2297-7-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-18Merge tag 'libnvdimm-for-4.10' of ↵Linus Torvalds2-1/+96
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The libnvdimm pull request is relatively small this time around due to some development topics being deferred to 4.11. As for this pull request the bulk of it has been in -next for several releases leading to one late fix being added (commit 868f036fee4b ("libnvdimm: fix mishandled nvdimm_clear_poison() return value")). It has received a build success notification from the 0day-kbuild robot and passes the latest libnvdimm unit tests. Summary: - Dynamic label support: To date namespace label support has been limited to disambiguating cases where PMEM (direct load/store) and BLK (mmio aperture) accessed-capacity alias on the same DIMM. Since 4.9 added support for multiple namespaces per PMEM-region there is value to support namespace labels even in the non-aliasing case. The presence of a valid namespace index block force-enables label support when the kernel would otherwise rely on region boundaries, and permits the region to be sub-divided. - Handle media errors in namespace metadata: Complement the error handling for media errors in namespace data areas with support for clearing errors on writes, and downgrading potential machine-check exceptions to simple i/o errors on read. - Device-DAX region attributes: Add 'align', 'id', and 'size' as attributes for device-dax regions. In particular this enables userspace tooling to generically size memory mapping and i/o operations. Prevent userspace from growing assumptions / dependencies about the parent device topology for a dax region. A libnvdimm namespace may not always be the parent device of a dax region. - Various cleanups and small fixes" * tag 'libnvdimm-for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: add region 'id', 'size', and 'align' attributes libnvdimm: fix mishandled nvdimm_clear_poison() return value libnvdimm: replace mutex_is_locked() warnings with lockdep_assert_held libnvdimm, pfn: fix align attribute libnvdimm, e820: use module_platform_driver libnvdimm, namespace: use octal for permissions libnvdimm, namespace: avoid multiple sector calculations libnvdimm: remove else after return in nsio_rw_bytes() libnvdimm, namespace: fix the type of name variable libnvdimm: use consistent naming for request_mem_region() nvdimm: use the right length of "pmem" libnvdimm: check and clear poison before writing to pmem tools/testing/nvdimm: dynamic label support libnvdimm: allow a platform to force enable label support libnvdimm: use generic iostat interfaces
2016-12-17Merge branch 'for-4.10/libnvdimm' into libnvdimm-for-nextDan Williams2-1/+96
2016-12-17dax: add region 'id', 'size', and 'align' attributesDan Williams1-0/+94
While this information is available by looking at the nvdimm parent device that may not always be the case when/if we add support for other memory regions. Tooling should not depend on walking a given ancestor topology that is not guaranteed by the device's class. For example, a device-dax instance will always have a dax_region parent, but it may not always have a libnvdimm "dax" device as a grandparent. Reported-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-12-14mm: use vmf->address instead of of vmf->virtual_addressJan Kara1-2/+1
Every single user of vmf->virtual_address typed that entry to unsigned long before doing anything with it so the type of virtual_address does not really provide us any additional safety. Just use masked vmf->address which already has the appropriate type. Link: http://lkml.kernel.org/r/1479460644-25076-3-git-send-email-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-06device-dax: fix private mapping restriction, permit read-onlyDan Williams1-1/+1
Hugh notes in response to commit 4cb19355ea19 "device-dax: fail all private mapping attempts": "I think that is more restrictive than you intended: haven't tried, but I believe it rejects a PROT_READ, MAP_SHARED, O_RDONLY fd mmap, leaving no way to mmap /dev/dax without write permission to it." Indeed it does restrict read-only mappings, switch to checking VM_MAYSHARE, not VM_SHARED. Cc: <stable@vger.kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Pawel Lebioda <pawel.lebioda@intel.com> Fixes: 4cb19355ea19 ("device-dax: fail all private mapping attempts") Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-11-28libnvdimm: use consistent naming for request_mem_region()Dan Williams1-1/+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>
2016-11-16device-dax: fail all private mapping attemptsDan Williams1-2/+2
The device-dax implementation originally tried to be tricky and allow private read-only mappings, but in the process allowed writable MAP_PRIVATE + MAP_NORESERVE mappings. For simplicity and predictability just fail all private mapping attempts since device-dax memory is statically allocated and will never support overcommit. Cc: <stable@vger.kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap") Reported-by: Pawel Lebioda <pawel.lebioda@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-28device-dax: check devm_nsio_enable() return valueDan Williams1-1/+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>
2016-10-27device-dax: fix percpu_ref_exit orderingDan Williams1-1/+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>
2016-10-27nvdimm: make CONFIG_NVDIMM_DAX 'bool'Arnd Bergmann1-1/+1
A bugfix just tried to address a randconfig build problem and introduced a variant of the same problem: with CONFIG_LIBNVDIMM=y and CONFIG_NVDIMM_DAX=m, the nvdimm module now fails to link: drivers/nvdimm/built-in.o: In function `to_nd_device_type': bus.c:(.text+0x1b5d): undefined reference to `is_nd_dax' drivers/nvdimm/built-in.o: In function `nd_region_notify_driver_action.constprop.2': region_devs.c:(.text+0x6b6c): undefined reference to `is_nd_dax' region_devs.c:(.text+0x6b8c): undefined reference to `to_nd_dax' drivers/nvdimm/built-in.o: In function `nd_region_probe': region.c:(.text+0x70f3): undefined reference to `nd_dax_create' drivers/nvdimm/built-in.o: In function `mode_show': namespace_devs.c:(.text+0xa196): undefined reference to `is_nd_dax' drivers/nvdimm/built-in.o: In function `nvdimm_namespace_common_probe': (.text+0xa55f): undefined reference to `is_nd_dax' drivers/nvdimm/built-in.o: In function `nvdimm_namespace_common_probe': (.text+0xa56e): undefined reference to `to_nd_dax' This reverts the earlier fix, making NVDIMM_DAX a 'bool' option again as it should be (it gets linked into the libnvdimm module). To fix the original problem, I'm adding a dependency on LIBNVDIMM to DEV_DAX_PMEM, which ensures we can't have that one built-in if the rest is a module. Fixes: 4e65e9381c7a ("/dev/dax: fix Kconfig dependency build breakage") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07Merge branch 'for-4.9/dax' into libnvdimm-for-nextDan Williams4-232/+362
2016-10-07dax: use correct dev_t valueArnd Bergmann1-2/+2
The dev_t variable in devm_create_dax_dev() is used before it's first set: drivers/dax/dax.c: In function 'devm_create_dax_dev': drivers/dax/dax.c:205:39: error: 'dev_t' may be used uninitialized in this function [-Werror=maybe-uninitialized] inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/dax/dax.c:688:8: note: 'dev_t' was declared here This reorders the code to how it looks correct to me. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 3bc52c45bac2 ("dax: define a unified inode/address_space for device-dax mappings") Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07dax: convert devm_create_dax_dev to PTR_ERRDan Williams3-10/+16
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>