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* mm: provide a saner PTE walking API for modulesPaolo Bonzini2021-02-261-2/+3
| | | | | | | | | | | | | | | | | | commit 9fd6dad1261a541b3f5fa7dc5b152222306e6702 upstream. Currently, the follow_pfn function is exported for modules but follow_pte is not. However, follow_pfn is very easy to misuse, because it does not provide protections (so most of its callers assume the page is writable!) and because it returns after having already unlocked the page table lock. Provide instead a simplified version of follow_pte that does not have the pmdpp and range arguments. The older version survives as follow_invalidate_pte() for use by fs/dax.c. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm: simplify follow_pte{,pmd}Christoph Hellwig2021-02-261-5/+4
| | | | | | | | | | | | | | | | | | | | | commit ff5c19ed4b087073cea38ff0edc80c23d7256943 upstream. Merge __follow_pte_pmd, follow_pte_pmd and follow_pte into a single follow_pte function and just pass two additional NULL arguments for the two previous follow_pte callers. [sfr@canb.auug.org.au: merge fix for "s390/pci: remove races against pte updates"] Link: https://lkml.kernel.org/r/20201111221254.7f6a3658@canb.auug.org.au Link: https://lkml.kernel.org/r/20201029101432.47011-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dax: pass NOWAIT flag to iomap_applyJeff Moyer2020-03-051-0/+3
| | | | | | | | | | | | | | | | | | [ Upstream commit 96222d53842dfe54869ec4e1b9d4856daf9105a2 ] fstests generic/471 reports a failure when run with MOUNT_OPTIONS="-o dax". The reason is that the initial pwrite to an empty file with the RWF_NOWAIT flag set does not return -EAGAIN. It turns out that dax_iomap_rw doesn't pass that flag through to iomap_apply. With this patch applied, generic/471 passes for me. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/x49r1z86e1d.fsf@segfault.boston.devel.redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* fs/dax: Fix pmd vs pte conflict detectionDan Williams2019-10-221-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | Users reported a v5.3 performance regression and inability to establish huge page mappings. A revised version of the ndctl "dax.sh" huge page unit test identifies commit 23c84eb78375 "dax: Fix missed wakeup with PMD faults" as the source. Update get_unlocked_entry() to check for NULL entries before checking the entry order, otherwise NULL is misinterpreted as a present pte conflict. The 'order' check needs to happen before the locked check as an unlocked entry at the wrong order must fallback to lookup the correct order. Reported-by: Jeff Smits <jeff.smits@intel.com> Reported-by: Doug Nelson <doug.nelson@intel.com> Cc: <stable@vger.kernel.org> Fixes: 23c84eb78375 ("dax: Fix missed wakeup with PMD faults") Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Link: https://lore.kernel.org/r/157167532455.3945484.11971474077040503994.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* dax: dax_layout_busy_page() should not unmap cow pagesVivek Goyal2019-08-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Vivek: "As of now dax_layout_busy_page() calls unmap_mapping_range() with last argument as 1, which says even unmap cow pages. I am wondering who needs to get rid of cow pages as well. I noticed one interesting side affect of this. I mount xfs with -o dax and mmaped a file with MAP_PRIVATE and wrote some data to a page which created cow page. Then I called fallocate() on that file to zero a page of file. fallocate() called dax_layout_busy_page() which unmapped cow pages as well and then I tried to read back the data I wrote and what I get is old data from persistent memory. I lost the data I had written. This read basically resulted in new fault and read back the data from persistent memory. This sounds wrong. Are there any users which need to unmap cow pages as well? If not, I am proposing changing it to not unmap cow pages. I noticed this while while writing virtio_fs code where when I tried to reclaim a memory range and that corrupted the executable and I was running from virtio-fs and program got segment violation." Dan: "In fact the unmap_mapping_range() in this path is only to synchronize against get_user_pages_fast() and force it to call back into the filesystem to re-establish the mapping. COW pages should be left untouched by dax_layout_busy_page()." Cc: <stable@vger.kernel.org> Fixes: 5fac7408d828 ("mm, fs, dax: handle layout changes to pinned dax mappings") Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Link: https://lore.kernel.org/r/20190802192956.GA3032@redhat.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* dax: Fix missed wakeup in put_unlocked_entry()Jan Kara2019-07-291-1/+1
| | | | | | | | | | | | | | | The condition checking whether put_unlocked_entry() needs to wake up following waiter got broken by commit 23c84eb78375 ("dax: Fix missed wakeup with PMD faults"). We need to wake the waiter whenever the passed entry is valid (i.e., non-NULL and not special conflict entry). This could lead to processes never being woken up when waiting for entry lock. Fix the condition. Cc: <stable@vger.kernel.org> Link: http://lore.kernel.org/r/20190729120228.GC17833@quack2.suse.cz Fixes: 23c84eb78375 ("dax: Fix missed wakeup with PMD faults") Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge tag 'iomap-5.3-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds2019-07-191-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull iomap split/cleanup from Darrick Wong: "As promised, here's the second part of the iomap merge for 5.3, in which we break up iomap.c into smaller files grouped by functional area so that it'll be easier in the long run to maintain cohesiveness of code units and to review incoming patches. There are no functional changes and fs/iomap.c split cleanly. Summary: - Regroup the fs/iomap.c code by major functional area so that we can start development for 5.4 from a more stable base" * tag 'iomap-5.3-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: iomap: move internal declarations into fs/iomap/ iomap: move the main iteration code into a separate file iomap: move the buffered IO code into a separate file iomap: move the direct IO code into a separate file iomap: move the SEEK_HOLE code into a separate file iomap: move the file mapping reporting code into a separate file iomap: move the swapfile code into a separate file iomap: start moving code to fs/iomap/
| * iomap: move internal declarations into fs/iomap/Darrick J. Wong2019-07-171-1/+0
| | | | | | | | | | | | | | | | Move internal function declarations out of fs/internal.h into include/linux/iomap.h so that our transition is complete. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* | Merge tag 'dax-for-5.3' of ↵Linus Torvalds2019-07-181-20/+33
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull dax updates from Dan Williams: "The fruits of a bug hunt in the fsdax implementation with Willy and a small feature update for device-dax: - Fix a hang condition that started triggering after the Xarray conversion of fsdax in the v4.20 kernel. - Add a 'resource' (root-only physical base address) sysfs attribute to device-dax instances to correlate memory-blocks onlined via the kmem driver with a given device instance" * tag 'dax-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: Fix missed wakeup with PMD faults device-dax: Add a 'resource' attribute
| * dax: Fix missed wakeup with PMD faultsMatthew Wilcox (Oracle)2019-07-161-20/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RocksDB can hang indefinitely when using a DAX file. This is due to a bug in the XArray conversion when handling a PMD fault and finding a PTE entry. We use the wrong index in the hash and end up waiting on the wrong waitqueue. There's actually no need to wait; if we find a PTE entry while looking for a PMD entry, we can return immediately as we know we should fall back to a PTE fault (which may not conflict with the lock held). We reuse the XA_RETRY_ENTRY to signal a conflicting entry was found. This value can never be found in an XArray while holding its lock, so it does not create an ambiguity. Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/CAPcyv4hwHpX-MkUEqxwdTj7wCCZCN4RV-L4jsnuwLGyL_UEG4A@mail.gmail.com Fixes: b15cd800682f ("dax: Convert page fault handlers to XArray") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Robert Barror <robert.barror@intel.com> Reported-by: Seema Pandit <seema.pandit@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2019-07-081-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes in this cycle are: - rwsem scalability improvements, phase #2, by Waiman Long, which are rather impressive: "On a 2-socket 40-core 80-thread Skylake system with 40 reader and writer locking threads, the min/mean/max locking operations done in a 5-second testing window before the patchset were: 40 readers, Iterations Min/Mean/Max = 1,807/1,808/1,810 40 writers, Iterations Min/Mean/Max = 1,807/50,344/151,255 After the patchset, they became: 40 readers, Iterations Min/Mean/Max = 30,057/31,359/32,741 40 writers, Iterations Min/Mean/Max = 94,466/95,845/97,098" There's a lot of changes to the locking implementation that makes it similar to qrwlock, including owner handoff for more fair locking. Another microbenchmark shows how across the spectrum the improvements are: "With a locking microbenchmark running on 5.1 based kernel, the total locking rates (in kops/s) on a 2-socket Skylake system with equal numbers of readers and writers (mixed) before and after this patchset were: # of Threads Before Patch After Patch ------------ ------------ ----------- 2 2,618 4,193 4 1,202 3,726 8 802 3,622 16 729 3,359 32 319 2,826 64 102 2,744" The changes are extensive and the patch-set has been through several iterations addressing various locking workloads. There might be more regressions, but unless they are pathological I believe we want to use this new implementation as the baseline going forward. - jump-label optimizations by Daniel Bristot de Oliveira: the primary motivation was to remove IPI disturbance of isolated RT-workload CPUs, which resulted in the implementation of batched jump-label updates. Beyond the improvement of the real-time characteristics kernel, in one test this patchset improved static key update overhead from 57 msecs to just 1.4 msecs - which is a nice speedup as well. - atomic64_t cross-arch type cleanups by Mark Rutland: over the last ~10 years of atomic64_t existence the various types used by the APIs only had to be self-consistent within each architecture - which means they became wildly inconsistent across architectures. Mark puts and end to this by reworking all the atomic64 implementations to use 's64' as the base type for atomic64_t, and to ensure that this type is consistently used for parameters and return values in the API, avoiding further problems in this area. - A large set of small improvements to lockdep by Yuyang Du: type cleanups, output cleanups, function return type and othr cleanups all around the place. - A set of percpu ops cleanups and fixes by Peter Zijlstra. - Misc other changes - please see the Git log for more details" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (82 commits) locking/lockdep: increase size of counters for lockdep statistics locking/atomics: Use sed(1) instead of non-standard head(1) option locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING x86/jump_label: Make tp_vec_nr static x86/percpu: Optimize raw_cpu_xchg() x86/percpu, sched/fair: Avoid local_clock() x86/percpu, x86/irq: Relax {set,get}_irq_regs() x86/percpu: Relax smp_processor_id() x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}() locking/rwsem: Guard against making count negative locking/rwsem: Adaptive disabling of reader optimistic spinning locking/rwsem: Enable time-based spinning on reader-owned rwsem locking/rwsem: Make rwsem->owner an atomic_long_t locking/rwsem: Enable readers spinning on writer locking/rwsem: Clarify usage of owner's nonspinaable bit locking/rwsem: Wake up almost all readers in wait queue locking/rwsem: More optimal RT task handling of null owner locking/rwsem: Always release wait_lock before waking up tasks locking/rwsem: Implement lock handoff to prevent lock starvation locking/rwsem: Make rwsem_spin_on_owner() return owner state ...
| * | locking/lockdep: Rename lockdep_assert_held_exclusive() -> ↵Nikolay Borisov2019-06-171-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lockdep_assert_held_write() All callers of lockdep_assert_held_exclusive() use it to verify the correct locking state of either a semaphore (ldisc_sem in tty, mmap_sem for perf events, i_rwsem of inode for dax) or rwlock by apparmor. Thus it makes sense to rename _exclusive to _write since that's the semantics callers care. Additionally there is already lockdep_assert_held_read(), which this new naming is more consistent with. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190531100651.3969-1-nborisov@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge tag 'dax-fix-5.2-rc8' of ↵Linus Torvalds2019-07-051-5/+4
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull dax fix from Dan Williams: "A single dax fix that has been soaking awaiting other fixes under discussion to join it. As it is getting late in the cycle lets proceed with this fix and save follow-on changes for post-v5.3-rc1. - Fix xarray entry association for mixed mappings" * tag 'dax-fix-5.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: Fix xarray entry association for mixed mappings
| * dax: Fix xarray entry association for mixed mappingsJan Kara2019-06-061-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When inserting entry into xarray, we store mapping and index in corresponding struct pages for memory error handling. When it happened that one process was mapping file at PMD granularity while another process at PTE granularity, we could wrongly deassociate PMD range and then reassociate PTE range leaving the rest of struct pages in PMD range without mapping information which could later cause missed notifications about memory errors. Fix the problem by calling the association / deassociation code if and only if we are really going to update the xarray (deassociating and associating zero or empty entries is just no-op so there's no reason to complicate the code with trying to avoid the calls for these cases). Cc: <stable@vger.kernel.org> Fixes: d2c997c0f145 ("fs, dax: use page->mapping to warn if truncate...") Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288Thomas Gleixner2019-06-051-9/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 263 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm: page_mkclean vs MADV_DONTNEED raceAneesh Kumar K.V2019-05-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MADV_DONTNEED is handled with mmap_sem taken in read mode. We call page_mkclean without holding mmap_sem. MADV_DONTNEED implies that pages in the region are unmapped and subsequent access to the pages in that range is handled as a new page fault. This implies that if we don't have parallel access to the region when MADV_DONTNEED is run we expect those range to be unallocated. w.r.t page_mkclean() we need to make sure that we don't break the MADV_DONTNEED semantics. MADV_DONTNEED check for pmd_none without holding pmd_lock. This implies we skip the pmd if we temporarily mark pmd none. Avoid doing that while marking the page clean. Keep the sequence same for dax too even though we don't support MADV_DONTNEED for dax mapping The bug was noticed by code review and I didn't observe any failures w.r.t test run. This is similar to commit 58ceeb6bec86d9140f9d91d71a710e963523d063 Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Date: Thu Apr 13 14:56:26 2017 -0700 thp: fix MADV_DONTNEED vs. MADV_FREE race commit ced108037c2aa542b3ed8b7afd1576064ad1362a Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Date: Thu Apr 13 14:56:20 2017 -0700 thp: fix MADV_DONTNEED vs. numa balancing race Link: http://lkml.kernel.org/r/20190321040610.14226-1-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc:"Kirill A . Shutemov" <kirill@shutemov.name> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/huge_memory: fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned ↵Dan Williams2019-05-141-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | addresses Starting with c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()") vmf_insert_pfn_pmd() internally calls pmdp_set_access_flags(). That helper enforces a pmd aligned @address argument via VM_BUG_ON() assertion. Update the implementation to take a 'struct vm_fault' argument directly and apply the address alignment fixup internally to fix crash signatures like: kernel BUG at arch/x86/mm/pgtable.c:515! invalid opcode: 0000 [#1] SMP NOPTI CPU: 51 PID: 43713 Comm: java Tainted: G OE 4.19.35 #1 [..] RIP: 0010:pmdp_set_access_flags+0x48/0x50 [..] Call Trace: vmf_insert_pfn_pmd+0x198/0x350 dax_iomap_fault+0xe82/0x1190 ext4_dax_huge_fault+0x103/0x1f0 ? __switch_to_asm+0x40/0x70 __handle_mm_fault+0x3f6/0x1370 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 handle_mm_fault+0xda/0x200 __do_page_fault+0x249/0x4f0 do_page_fault+0x32/0x110 ? page_fault+0x8/0x30 page_fault+0x1e/0x30 Link: http://lkml.kernel.org/r/155741946350.372037.11148198430068238140.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Piotr Balcer <piotr.balcer@intel.com> Tested-by: Yan Ma <yan.ma@intel.com> Tested-by: Pankaj Gupta <pagupta@redhat.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Chandan Rajendra <chandan@linux.ibm.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/dax: Deposit pagetable even when installing zero pageAneesh Kumar K.V2019-03-131-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Architectures like ppc64 use the deposited page table to store hardware page table slot information. Make sure we deposit a page table when using zero page at the pmd level for hash. Without this we hit Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc000000000082a74 Oops: Kernel access of bad area, sig: 11 [#1] .... NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 Call Trace: hash_page_mm+0x43c/0x740 do_hash_page+0x2c/0x3c copy_from_iter_flushcache+0xa4/0x4a0 pmem_copy_from_iter+0x2c/0x50 [nd_pmem] dax_copy_from_iter+0x40/0x70 dax_iomap_actor+0x134/0x360 iomap_apply+0xfc/0x1b0 dax_iomap_rw+0xac/0x130 ext4_file_write_iter+0x254/0x460 [ext4] __vfs_write+0x120/0x1e0 vfs_write+0xd8/0x220 SyS_write+0x6c/0x110 system_call+0x3c/0x130 Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") Cc: <stable@vger.kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* dax: Flush partial PMDs correctlyMatthew Wilcox2019-03-011-10/+9
| | | | | | | | | | | | | | | | The radix tree would rewind the index in an iterator to the lowest index of a multi-slot entry. The XArray iterators instead leave the index unchanged, but I overlooked that when converting DAX from the radix tree to the XArray. Adjust the index that we use for flushing to the start of the PMD range. Fixes: c1901cd33cf4 ("page cache: Convert find_get_entries_tag to XArray") Cc: <stable@vger.kernel.org> Reported-by: Piotr Balcer <piotr.balcer@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* fs/dax: NIT fix comment regarding start/end vs rangeIra Weiny2019-02-121-1/+1
| | | | | | Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2") Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* fs/dax: Convert to use vmf_error()Souptick Joarder2019-02-121-3/+1
| | | | | | | | This code is converted to use vmf_error(). Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge tag 'dax-fix-4.21' of ↵Linus Torvalds2018-12-311-9/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull dax fix from Dan Williams: "Clean up unnecessary usage of prepare_to_wait_exclusive(). While I feel a bit silly sending a single-commit pull-request there is nothing else queued up for dax this cycle. This change has shipped in -next for multiple releases" * tag 'dax-fix-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: Use non-exclusive wait in wait_entry_unlocked()
| * dax: Use non-exclusive wait in wait_entry_unlocked()Dan Williams2018-12-211-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | get_unlocked_entry() uses an exclusive wait because it is guaranteed to eventually obtain the lock and follow on with an unlock+wakeup cycle. The wait_entry_unlocked() path does not have the same guarantee. Rather than open-code an extra wakeup, just switch to a non-exclusive wait. Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | mm/mmu_notifier: use structure for invalidate_range_start/end calls v2Jérôme Glisse2018-12-281-3/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid having to change many call sites everytime we want to add a parameter use a structure to group all parameters for the mmu_notifier invalidate_range_start/end cakks. No functional changes with this patch. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/20181205053628.3210-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> From: Jérôme Glisse <jglisse@redhat.com> Subject: mm/mmu_notifier: use structure for invalidate_range_start/end calls v3 fix build warning in migrate.c when CONFIG_MMU_NOTIFIER=n Link: http://lkml.kernel.org/r/20181213171330.8489-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dax: Fix unlock mismatch with updated APIMatthew Wilcox2018-12-041-13/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Internal to dax_unlock_mapping_entry(), dax_unlock_entry() is used to store a replacement entry in the Xarray at the given xas-index with the DAX_LOCKED bit clear. When called, dax_unlock_entry() expects the unlocked value of the entry relative to the current Xarray state to be specified. In most contexts dax_unlock_entry() is operating in the same scope as the matched dax_lock_entry(). However, in the dax_unlock_mapping_entry() case the implementation needs to recall the original entry. In the case where the original entry is a 'pmd' entry it is possible that the pfn performed to do the lookup is misaligned to the value retrieved in the Xarray. Change the api to return the unlock cookie from dax_lock_page() and pass it to dax_unlock_page(). This fixes a bug where dax_unlock_page() was assuming that the page was PMD-aligned if the entry was a PMD entry with signatures like: WARNING: CPU: 38 PID: 1396 at fs/dax.c:340 dax_insert_entry+0x2b2/0x2d0 RIP: 0010:dax_insert_entry+0x2b2/0x2d0 [..] Call Trace: dax_iomap_pte_fault.isra.41+0x791/0xde0 ext4_dax_huge_fault+0x16f/0x1f0 ? up_read+0x1c/0xa0 __do_fault+0x1f/0x160 __handle_mm_fault+0x1033/0x1490 handle_mm_fault+0x18b/0x3d0 Link: https://lkml.kernel.org/r/20181130154902.GL10377@bombadil.infradead.org Fixes: 9f32d221301c ("dax: Convert dax_lock_mapping_entry to XArray") Reported-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Matthew Wilcox <willy@infradead.org> Tested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* dax: Don't access a freed inodeMatthew Wilcox2018-11-281-3/+29
| | | | | | | | | | | | | After we drop the i_pages lock, the inode can be freed at any time. The get_unlocked_entry() code has no choice but to reacquire the lock, so it can't be used here. Create a new wait_entry_unlocked() which takes care not to acquire the lock or dereference the address_space in any way. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Cc: <stable@vger.kernel.org> Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* dax: Check page->mapping isn't NULLMatthew Wilcox2018-11-281-1/+1
| | | | | | | | | | | | | | If we race with inode destroy, it's possible for page->mapping to be NULL before we even enter this routine, as well as after having slept waiting for the dax entry to become unlocked. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Cc: <stable@vger.kernel.org> Reported-by: Jan Kara <jack@suse.cz> Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* dax: Avoid losing wakeup in dax_lock_mapping_entryMatthew Wilcox2018-11-191-0/+1
| | | | | | | | | After calling get_unlocked_entry(), you have to call put_unlocked_entry() to avoid subsequent waiters losing wakeups. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Fix huge page faultsMatthew Wilcox2018-11-171-8/+4
| | | | | | | | | | | | | | | | | Using xas_load() with a PMD-sized xa_state would work if either a PMD-sized entry was present or a PTE sized entry was present in the first 64 entries (of the 512 PTEs in a PMD on x86). If there was no PTE in the first 64 entries, grab_mapping_entry() would believe there were no entries present, allocate a PMD-sized entry and overwrite the PTE in the page cache. Use xas_find_conflict() instead which turns out to simplify both get_unlocked_entry() and grab_mapping_entry(). Also remove a WARN_ON_ONCE from grab_mapping_entry() as it will have already triggered in get_unlocked_entry(). Fixes: cfc93c6c6c96 ("dax: Convert dax_insert_pfn_mkwrite to XArray") Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Fix dax_unlock_mapping_entry for PMD pagesMatthew Wilcox2018-11-171-9/+8
| | | | | | | | | | Device DAX PMD pages do not set the PageHead bit for compound pages. Fix for now by retrieving the PMD bit from the entry, but eventually we will be passed the page size by the caller. Reported-by: Dan Williams <dan.j.williams@intel.com> Fixes: 9f32d221301c ("dax: Convert dax_lock_mapping_entry to XArray") Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Reinstate RCU protection of inodeMatthew Wilcox2018-11-161-3/+19
| | | | | | | | | | | | For the device-dax case, it is possible that the inode can go away underneath us. The rcu_read_lock() was there to prevent it from being freed, and not (as I thought) to protect the tree. Bring back the rcu_read_lock() protection. Also add a little kernel-doc; while this function is not exported to modules, it is used from outside dax.c Reported-by: Dan Williams <dan.j.williams@intel.com> Fixes: 9f32d221301c ("dax: Convert dax_lock_mapping_entry to XArray") Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Make sure the unlocking entry isn't lockedMatthew Wilcox2018-11-161-0/+1
| | | | | | | | I wrote the semantics in the commit message, but didn't document it in the source code. Use a BUG_ON instead (if any code does do this, it's really buggy; we can't recover and it's worth taking the machine down). Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Remove optimisation from dax_lock_mapping_entryMatthew Wilcox2018-11-161-5/+2
| | | | | | | | | Skipping some of the revalidation after we sleep can lead to returning a mapping which has already been freed. Just drop this optimisation. Reported-by: Dan Williams <dan.j.williams@intel.com> Fixes: 9f32d221301c ("dax: Convert dax_lock_mapping_entry to XArray") Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Convert page fault handlers to XArrayMatthew Wilcox2018-10-211-301/+128
| | | | | | | This is the last part of DAX to be converted to the XArray so remove all the old helper functions. Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Convert dax_lock_mapping_entry to XArrayMatthew Wilcox2018-10-211-48/+35
| | | | | | | Instead of always retrying when we slept, only retry if the page has moved. Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Convert dax writeback to XArrayMatthew Wilcox2018-10-211-68/+62
| | | | | | Use XArray iteration instead of a pagevec. Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Convert __dax_invalidate_entry to XArrayMatthew Wilcox2018-10-211-8/+9
| | | | | | Avoids walking the radix tree multiple times looking for tags. Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Convert dax_layout_busy_page to XArrayMatthew Wilcox2018-10-211-43/+21
| | | | | | | | Instead of using a pagevec, just use the XArray iterators. Add a conditional rescheduling point which probably should have been there in the original. Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Convert dax_insert_pfn_mkwrite to XArrayMatthew Wilcox2018-10-211-32/+117
| | | | | | | | | | | Add some XArray-based helper functions to replace the radix tree based metaphors currently in use. The biggest change is that converted code doesn't see its own lock bit; get_unlocked_entry() always returns an entry with the lock bit clear. So we don't have to mess around loading the current entry and clearing the lock bit; we can just store the unlocked entry that we already have. Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Hash on XArray instead of mappingMatthew Wilcox2018-10-211-14/+15
| | | | | | | | | Since the XArray is embedded in the struct address_space, its address contains exactly as much entropy as the address of the mapping. This patch is purely preparatory for later patches which will simplify the wait/wake interfaces. Signed-off-by: Matthew Wilcox <willy@infradead.org>
* dax: Rename some functionsMatthew Wilcox2018-10-211-44/+42
| | | | | | | Remove mentions of 'radix' and 'radix tree'. Simplify some names by dropping the word 'mapping'. Signed-off-by: Matthew Wilcox <willy@infradead.org>
* xarray: Replace exceptional entriesMatthew Wilcox2018-09-291-57/+55
| | | | | | | | | | | | | Introduce xarray value entries and tagged pointers to replace radix tree exceptional entries. This is a slight change in encoding to allow the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a value entry). It is also a change in emphasis; exceptional entries are intimidating and different. As the comment explains, you can choose to store values or pointers in the xarray and they are both first-class citizens. Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Josef Bacik <jbacik@fb.com>
* filesystem-dax: Fix use of zero pageMatthew Wilcox2018-09-111-11/+2
| | | | | | | | | | | | Use my_zero_pfn instead of ZERO_PAGE(), and pass the vaddr to it instead of zero so it works on MIPS and s390 who reference the vaddr to select a zero page. Cc: <stable@vger.kernel.org> Fixes: 91d25ba8a6b0 ("dax: use common 4k zero page for dax mmap reads") Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge tag 'libnvdimm-for-4.19_dax-memory-failure' of ↵Linus Torvalds2018-08-251-9/+116
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm memory-failure update from Dave Jiang: "As it stands, memory_failure() gets thoroughly confused by dev_pagemap backed mappings. The recovery code has specific enabling for several possible page states and needs new enabling to handle poison in dax mappings. In order to support reliable reverse mapping of user space addresses: 1/ Add new locking in the memory_failure() rmap path to prevent races that would typically be handled by the page lock. 2/ Since dev_pagemap pages are hidden from the page allocator and the "compound page" accounting machinery, add a mechanism to determine the size of the mapping that encompasses a given poisoned pfn. 3/ Given pmem errors can be repaired, change the speculatively accessed poison protection, mce_unmap_kpfn(), to be reversible and otherwise allow ongoing access from the kernel. A side effect of this enabling is that MADV_HWPOISON becomes usable for dax mappings, however the primary motivation is to allow the system to survive userspace consumption of hardware-poison via dax. Specifically the current behavior is: mce: Uncorrected hardware memory error in user-access at af34214200 {1}[Hardware Error]: It has been corrected by h/w and requires no further action mce: [Hardware Error]: Machine check events logged {1}[Hardware Error]: event severity: corrected Memory failure: 0xaf34214: reserved kernel page still referenced by 1 users [..] Memory failure: 0xaf34214: recovery action for reserved kernel page: Failed mce: Memory error not recovered <reboot> ...and with these changes: Injecting memory failure for pfn 0x20cb00 at process virtual address 0x7f763dd00000 Memory failure: 0x20cb00: Killing dax-pmd:5421 due to hardware memory corruption Memory failure: 0x20cb00: recovery action for dax page: Recovered Given all the cross dependencies I propose taking this through nvdimm.git with acks from Naoya, x86/core, x86/RAS, and of course dax folks" * tag 'libnvdimm-for-4.19_dax-memory-failure' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm, pmem: Restore page attributes when clearing errors x86/memory_failure: Introduce {set, clear}_mce_nospec() x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses mm, memory_failure: Teach memory_failure() about dev_pagemap pages filesystem-dax: Introduce dax_lock_mapping_entry() mm, memory_failure: Collect mapping size in collect_procs() mm, madvise_inject_error: Let memory_failure() optionally take a page reference mm, dev_pagemap: Do not clear ->mapping on final put mm, madvise_inject_error: Disable MADV_SOFT_OFFLINE for ZONE_DEVICE pages filesystem-dax: Set page->index device-dax: Set page->index device-dax: Enable page_mapping() device-dax: Convert to vmf_insert_mixed and vm_fault_t
| * filesystem-dax: Introduce dax_lock_mapping_entry()Dan Williams2018-07-231-6/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for implementing support for memory poison (media error) handling via dax mappings, implement a lock_page() equivalent. Poison error handling requires rmap and needs guarantees that the page->mapping association is maintained / valid (inode not freed) for the duration of the lookup. In the device-dax case it is sufficient to simply hold a dev_pagemap reference. In the filesystem-dax case we need to use the entry lock. Export the entry lock via dax_lock_mapping_entry() that uses rcu_read_lock() to protect against the inode being freed, and revalidates the page->mapping association under xa_lock(). Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
| * filesystem-dax: Set page->indexDan Williams2018-07-201-3/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In support of enabling memory_failure() handling for filesystem-dax mappings, set ->index to the pgoff of the page. The rmap implementation requires ->index to bound the search through the vma interval tree. The index is set and cleared at dax_associate_entry() and dax_disassociate_entry() time respectively. Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
* | Merge tag 'libnvdimm-for-4.19_misc' of ↵Linus Torvalds2018-08-251-9/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dave Jiang: "Collection of misc libnvdimm patches for 4.19 submission: - Adding support to read locked nvdimm capacity. - Change test code to make DSM failure code injection an override. - Add support for calculate maximum contiguous area for namespace. - Add support for queueing a short ARS when there is on going ARS for nvdimm. - Allow NULL to be passed in to ->direct_access() for kaddr and pfn params. - Improve smart injection support for nvdimm emulation testing. - Fix test code that supports for emulating controller temperature. - Fix hang on error before devm_memremap_pages() - Fix a bug that causes user memory corruption when data returned to user for ars_status. - Maintainer updates for Ross Zwisler emails and adding Jan Kara to fsdax" * tag 'libnvdimm-for-4.19_misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm: fix ars_status output length calculation device-dax: avoid hang on error before devm_memremap_pages() tools/testing/nvdimm: improve emulation of smart injection filesystem-dax: Do not request kaddr and pfn when not required md/dm-writecache: Don't request pointer dummy_addr when not required dax/super: Do not request a pointer kaddr when not required tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access() s390, dcssblk: kaddr and pfn can be NULL to ->direct_access() libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access() acpi/nfit: queue issuing of ars when an uc error notification comes in libnvdimm: Export max available extent libnvdimm: Use max contiguous area for namespace size MAINTAINERS: Add Jan Kara for filesystem DAX MAINTAINERS: update Ross Zwisler's email address tools/testing/nvdimm: Fix support for emulating controller temperature tools/testing/nvdimm: Make DSM failure code injection an override acpi, nfit: Prefer _DSM over _LSR for namespace label reads libnvdimm: Introduce locked DIMM capacity support
| * | filesystem-dax: Do not request kaddr and pfn when not requiredHuaisheng Ye2018-07-301-9/+4
| |/ | | | | | | | | | | | | | | | | | | Some functions within fs/dax don't need to get local pointer kaddr or variable pfn from direct_access. Using NULL instead of having to pass in useless pointer or variable that caller then just throw away. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
* / dax: dax_layout_busy_page() warn on !exceptionalRoss Zwisler2018-07-291-1/+9
|/ | | | | | | | | | | | Inodes using DAX should only ever have exceptional entries in their page caches. Make this clear by warning if the iteration in dax_layout_busy_page() ever sees a non-exceptional entry, and by adding a comment for the pagevec_release() call which only deals with struct page pointers. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
* Merge tag 'libnvdimm-for-4.18' of ↵Linus Torvalds2018-06-081-25/+111
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "This adds a user for the new 'bytes-remaining' updates to memcpy_mcsafe() that you already received through Ingo via the x86-dax- for-linus pull. Not included here, but still targeting this cycle, is support for handling memory media errors (poison) consumed via userspace dax mappings. Summary: - DAX broke a fundamental assumption of truncate of file mapped pages. The truncate path assumed that it is safe to disconnect a pinned page from a file and let the filesystem reclaim the physical block. With DAX the page is equivalent to the filesystem block. Introduce dax_layout_busy_page() to enable filesystems to wait for pinned DAX pages to be released. Without this wait a filesystem could allocate blocks under active device-DMA to a new file. - DAX arranges for the block layer to be bypassed and uses dax_direct_access() + copy_to_iter() to satisfy read(2) calls. However, the memcpy_mcsafe() facility is available through the pmem block driver. In order to safely handle media errors, via the DAX block-layer bypass, introduce copy_to_iter_mcsafe(). - Fix cache management policy relative to the ACPI NFIT Platform Capabilities Structure to properly elide cache flushes when they are not necessary. The table indicates whether CPU caches are power-fail protected. Clarify that a deep flush is always performed on REQ_{FUA,PREFLUSH} requests" * tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits) dax: Use dax_write_cache* helpers libnvdimm, pmem: Do not flush power-fail protected CPU caches libnvdimm, pmem: Unconditionally deep flush on *sync libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH acpi, nfit: Remove ecc_unit_size dax: dax_insert_mapping_entry always succeeds libnvdimm, e820: Register all pmem resources libnvdimm: Debug probe times linvdimm, pmem: Preserve read-only setting for pmem devices x86, nfit_test: Add unit test for memcpy_mcsafe() pmem: Switch to copy_to_iter_mcsafe() dax: Report bytes remaining in dax_iomap_actor() dax: Introduce a ->copy_to_iter dax operation uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation xfs, dax: introduce xfs_break_dax_layouts() xfs: prepare xfs_break_layouts() for another layout type xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL mm, fs, dax: handle layout changes to pinned dax mappings mm: fix __gup_device_huge vs unmap mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS ...
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