- 15 Jan, 2020 16 commits
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David Howells authored
Split various bits relating to mount parameterisation out from fs/nfs/super.c into their own file to form the basis of filesystem context handling for NFS. No other changes are made to the code beyond removing 'static' qualifiers. Signed-off-by:
David Howells <dhowells@redhat.com> Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Anna Schumaker <Anna.Schumaker@Netapp.com>
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Al Viro authored
it's always either nfs_set_sb_security() or nfs_clone_sb_security(), the choice being controlled by mount_info->cloned != NULL. No need to add methods, especially when both instances live right next to the caller and are never accessed anywhere else. Reviewed-by:
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Al Viro authored
We used to check ->i_op for being nfs_dir_inode_operations. With separate inode_operations for v3 and v4 that became bogus, but rather than going for protocol-dependent comparison we could've just checked ->i_fop instead; _that_ is the same for all protocol versions. Reviewed-by:
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Al Viro authored
The only possible values are nfs_fill_super and nfs_clone_super. The latter is used only when crossing into a submount and it is almost identical to the former; the only differences are * ->s_time_gran unconditionally set to 1 (even for v2 mounts). Regression dating back to 2012, actually. * ->s_blocksize/->s_blocksize_bits set to that of parent. Rather than messing with the method, stash ->s_blocksize_bits in mount_info in submount case and after the (now unconditional) call of nfs_fill_super() override ->s_blocksize/->s_blocksize_bits if that has been set. Reviewed-by:
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Al Viro authored
pick it from mount_info Reviewed-by:
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Al Viro authored
Make it static, even. And remove a stale extern of (long-gone) nfs_xdev_mount_common() from internal.h, while we are at it. Reviewed-by:
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Al Viro authored
they are identical now... Reviewed-by:
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Al Viro authored
Reviewed-by:
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Al Viro authored
That will allow to get rid of passing those references around in quite a few places. Moreover, that will allow to merge xdev and remote file_system_type. Reviewed-by:
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Al Viro authored
Do it in nfs_do_submount() instead. As a side benefit, nfs_clone_data doesn't need ->fh and ->fattr anymore. Reviewed-by:
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Al Viro authored
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Al Viro authored
nothing in it will be looking at that thing anyway Reviewed-by:
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Al Viro authored
They are identical now. Reviewed-by:
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Al Viro authored
Do that (fhandle allocation, setting struct server up) in nfs4_referral_mount() and nfs4_try_mount() resp. and pass the server and pointer to mount_info into nfs_do_root_mount() so that nfs4_remote_referral_mount()/nfs_remote_mount() could be merged. Since we are moving stuff from ->mount() instances to the points prior to vfs_kern_mount() that would trigger those, we need to make sure that do_nfs_root_mount() will do the corresponding cleanup itself if it doesn't trigger those ->mount() instances. Reviewed-by:
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Al Viro authored
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Al Viro authored
Allow it to take ERR_PTR() for server and return ERR_CAST() of it in such case. All callers used to open-code that... Reviewed-by:
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- 14 Jan, 2020 24 commits
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git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds authored
Pull NFS client bugfixes from Anna Schumaker: "Three NFS over RDMA fixes for bugs Chuck found that can be hit during device removal: - Fix create_qp crash on device unload - Fix completion wait during device removal - Fix oops in receive handler after device removal" * tag 'nfs-for-5.5-2' of git://git.linux-nfs.org/projects/anna/linux-nfs: xprtrdma: Fix oops in Receive handler after device removal xprtrdma: Fix completion wait during device removal xprtrdma: Fix create_qp crash on device unload
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Chuck Lever authored
Since v5.4, a device removal occasionally triggered this oops: Dec 2 17:13:53 manet kernel: BUG: unable to handle page fault for address: 0000000c00000219 Dec 2 17:13:53 manet kernel: #PF: supervisor read access in kernel mode Dec 2 17:13:53 manet kernel: #PF: error_code(0x0000) - not-present page Dec 2 17:13:53 manet kernel: PGD 0 P4D 0 Dec 2 17:13:53 manet kernel: Oops: 0000 [#1] SMP Dec 2 17:13:53 manet kernel: CPU: 2 PID: 468 Comm: kworker/2:1H Tainted: G W 5.4.0-00050-g53717e43af61 #883 Dec 2 17:13:53 manet kernel: Hardware name: Supermicro SYS-6028R-T/X10DRi, BIOS 1.1a 10/16/2015 Dec 2 17:13:53 manet kernel: Workqueue: ib-comp-wq ib_cq_poll_work [ib_core] Dec 2 17:13:53 manet kernel: RIP: 0010:rpcrdma_wc_receive+0x7c/0xf6 [rpcrdma] Dec 2 17:13:53 manet kernel: Code: 6d 8b 43 14 89 c1 89 45 78 48 89 4d 40 8b 43 2c 89 45 14 8b 43 20 89 45 18 48 8b 45 20 8b 53 14 48 8b 30 48 8b 40 10 48 8b 38 <48> 8b 87 18 02 00 00 48 85 c0 75 18 48 8b 05 1e 24 c4 e1 48 85 c0 Dec 2 17:13:53 manet kernel: RSP: 0018:ffffc900035dfe00 EFLAGS: 00010246 Dec 2 17:13:53 manet kernel: RAX: ffff888467290000 RBX: ffff88846c638400 RCX: 0000000000000048 Dec 2 17:13:53 manet kernel: RDX: 0000000000000048 RSI: 00000000f942e000 RDI: 0000000c00000001 Dec 2 17:13:53 manet kernel: RBP: ffff888467611b00 R08: ffff888464e4a3c4 R09: 0000000000000000 Dec 2 17:13:53 manet kernel: R10: ffffc900035dfc88 R11: fefefefefefefeff R12: ffff888865af4428 Dec 2 17:13:53 manet kernel: R13: ffff888466023000 R14: ffff88846c63f000 R15: 0000000000000010 Dec 2 17:13:53 manet kernel: FS: 0000000000000000(0000) GS:ffff88846fa80000(0000) knlGS:0000000000000000 Dec 2 17:13:53 manet kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Dec 2 17:13:53 manet kernel: CR2: 0000000c00000219 CR3: 0000000002009002 CR4: 00000000001606e0 Dec 2 17:13:53 manet kernel: Call Trace: Dec 2 17:13:53 manet kernel: __ib_process_cq+0x5c/0x14e [ib_core] Dec 2 17:13:53 manet kernel: ib_cq_poll_work+0x26/0x70 [ib_core] Dec 2 17:13:53 manet kernel: process_one_work+0x19d/0x2cd Dec 2 17:13:53 manet kernel: ? cancel_delayed_work_sync+0xf/0xf Dec 2 17:13:53 manet kernel: worker_thread+0x1a6/0x25a Dec 2 17:13:53 manet kernel: ? cancel_delayed_work_sync+0xf/0xf Dec 2 17:13:53 manet kernel: kthread+0xf4/0xf9 Dec 2 17:13:53 manet kernel: ? kthread_queue_delayed_work+0x74/0x74 Dec 2 17:13:53 manet kernel: ret_from_fork+0x24/0x30 The proximal cause is that this rpcrdma_rep has a rr_rdmabuf that is still pointing to the old ib_device, which has been freed. The only way that is possible is if this rpcrdma_rep was not destroyed by rpcrdma_ia_remove. Debugging showed that was indeed the case: this rpcrdma_rep was still in use by a completing RPC at the time of the device removal, and thus wasn't on the rep free list. So, it was not found by rpcrdma_reps_destroy(). The fix is to introduce a list of all rpcrdma_reps so that they all can be found when a device is removed. That list is used to perform only regbuf DMA unmapping, replacing that call to rpcrdma_reps_destroy(). Meanwhile, to prevent corruption of this list, I've moved the destruction of temp rpcrdma_rep objects to rpcrdma_post_recvs(). rpcrdma_xprt_drain() ensures that post_recvs (and thus rep_destroy) is not invoked while rpcrdma_reps_unmap is walking rb_all_reps, thus protecting the rb_all_reps list. Fixes: b0b227f0 ("xprtrdma: Use an llist to manage free rpcrdma_reps") Signed-off-by:
Chuck Lever <chuck.lever@oracle.com> Signed-off-by:
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Chuck Lever authored
I've found that on occasion, "rmmod <dev>" will hang while if an NFS is under load. Ensure that ri_remove_done is initialized only just before the transport is woken up to force a close. This avoids the completion possibly getting initialized again while the CM event handler is waiting for a wake-up. Fixes: bebd0318 ("xprtrdma: Support unplugging an HCA from under an NFS mount") Signed-off-by:
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Chuck Lever authored
On device re-insertion, the RDMA device driver crashes trying to set up a new QP: Nov 27 16:32:06 manet kernel: BUG: kernel NULL pointer dereference, address: 00000000000001c0 Nov 27 16:32:06 manet kernel: #PF: supervisor write access in kernel mode Nov 27 16:32:06 manet kernel: #PF: error_code(0x0002) - not-present page Nov 27 16:32:06 manet kernel: PGD 0 P4D 0 Nov 27 16:32:06 manet kernel: Oops: 0002 [#1] SMP Nov 27 16:32:06 manet kernel: CPU: 1 PID: 345 Comm: kworker/u28:0 Tainted: G W 5.4.0 #852 Nov 27 16:32:06 manet kernel: Hardware name: Supermicro SYS-6028R-T/X10DRi, BIOS 1.1a 10/16/2015 Nov 27 16:32:06 manet kernel: Workqueue: xprtiod xprt_rdma_connect_worker [rpcrdma] Nov 27 16:32:06 manet kernel: RIP: 0010:atomic_try_cmpxchg+0x2/0x12 Nov 27 16:32:06 manet kernel: Code: ff ff 48 8b 04 24 5a c3 c6 07 00 0f 1f 40 00 c3 31 c0 48 81 ff 08 09 68 81 72 0c 31 c0 48 81 ff 83 0c 68 81 0f 92 c0 c3 8b 06 <f0> 0f b1 17 0f 94 c2 84 d2 75 02 89 06 88 d0 c3 53 ba 01 00 00 00 Nov 27 16:32:06 manet kernel: RSP: 0018:ffffc900035abbf0 EFLAGS: 00010046 Nov 27 16:32:06 manet kernel: RAX: 0000000000000000 RBX: 00000000000001c0 RCX: 0000000000000000 Nov 27 16:32:06 manet kernel: RDX: 0000000000000001 RSI: ffffc900035abbfc RDI: 00000000000001c0 Nov 27 16:32:06 manet kernel: RBP: ffffc900035abde0 R08: 000000000000000e R09: ffffffffffffc000 Nov 27 16:32:06 manet kernel: R10: 0000000000000000 R11: 000000000002e800 R12: ffff88886169d9f8 Nov 27 16:32:06 manet kernel: R13: ffff88886169d9f4 R14: 0000000000000246 R15: 0000000000000000 Nov 27 16:32:06 manet kernel: FS: 0000000000000000(0000) GS:ffff88846fa40000(0000) knlGS:0000000000000000 Nov 27 16:32:06 manet kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Nov 27 16:32:06 manet kernel: CR2: 00000000000001c0 CR3: 0000000002009006 CR4: 00000000001606e0 Nov 27 16:32:06 manet kernel: Call Trace: Nov 27 16:32:06 manet kernel: do_raw_spin_lock+0x2f/0x5a Nov 27 16:32:06 manet kernel: create_qp_common.isra.47+0x856/0xadf [mlx4_ib] Nov 27 16:32:06 manet kernel: ? slab_post_alloc_hook.isra.60+0xa/0x1a Nov 27 16:32:06 manet kernel: ? __kmalloc+0x125/0x139 Nov 27 16:32:06 manet kernel: mlx4_ib_create_qp+0x57f/0x972 [mlx4_ib] The fix is to copy the qp_init_attr struct that was just created by rpcrdma_ep_create() instead of using the one from the previous connection instance. Fixes: 98ef77d1 ("xprtrdma: Send Queue size grows after a reconnect") Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linuxLinus Torvalds authored
Pull parisc fixes from Helge Deller: "A boot crash fix by Mike Rapoport and a printk fix by Krzysztof Kozlowski" * 'parisc-5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: fix map_pages() to actually populate upper directory parisc: Use proper printk format for resource_size_t
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git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playgroundLinus Torvalds authored
Pull asm-generic fixes from Arnd Bergmann: "Here are two bugfixes from Mike Rapoport, both fixing compile-time errors for the nds32 architecture that were recently introduced" * tag 'asm-generic-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground: nds32: fix build failure caused by page table folding updates asm-generic/nds32: don't redefine cacheflush primitives
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Two simple fixes in the upper drivers (so both fairly core), one in enclosures, which fixes replugging a device into an enclosure slot and one in the disk driver which fixes revalidating a drive with protection information (PI) to make it a non-PI drive ... previously we were still remembering the old PI state. Both fixed issues are quite rare in the field" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: enclosure: Fix stale device oops with hot replug scsi: sd: Clear sdkp->protection_type if disk is reformatted without PI
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Linus Torvalds authored
Merge misc fixes from David Howells. Two afs fixes and a key refcounting fix. * dhowells: afs: Fix afs_lookup() to not clobber the version on a new dentry afs: Fix use-after-loss-of-ref keys: Fix request_key() cache
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David Howells authored
Fix afs_lookup() to not clobber the version set on a new dentry by afs_do_lookup() - especially as it's using the wrong version of the version (we need to use the one given to us by whatever op the dir contents correspond to rather than what's in the afs_vnode). Fixes: 9dd0b82e ("afs: Fix missing dentry data version updating") Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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David Howells authored
afs_lookup() has a tracepoint to indicate the outcome of d_splice_alias(), passing it the inode to retrieve the fid from. However, the function gave up its ref on that inode when it called d_splice_alias(), which may have failed and dropped the inode. Fix this by caching the fid. Fixes: 80548b03 ("afs: Add more tracepoints") Reported-by:
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David Howells authored
When the key cached by request_key() and co. is cleaned up on exit(), the code looks in the wrong task_struct, and so clears the wrong cache. This leads to anomalies in key refcounting when doing, say, a kernel build on an afs volume, that then trigger kasan to report a use-after-free when the key is viewed in /proc/keys. Fix this by making exit_creds() look in the passed-in task_struct rather than in current (the task_struct cleanup code is deferred by RCU and potentially run in another task). Fixes: 7743c48e ("keys: Cache result of request_key*() temporarily in task_struct") Signed-off-by:
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Linus Torvalds authored
Merge misc fixes from Andrew Morton: "11 mm fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: khugepaged: add trace status description for SCAN_PAGE_HAS_PRIVATE mm: memcg/slab: call flush_memcg_workqueue() only if memcg workqueue is valid mm/page-writeback.c: improve arithmetic divisions mm/page-writeback.c: use div64_ul() for u64-by-unsigned-long divide mm/page-writeback.c: avoid potential division by zero in wb_min_max_ratio() mm, debug_pagealloc: don't rely on static keys too early mm: memcg/slab: fix percpu slab vmstats flushing mm/shmem.c: thp, shmem: fix conflict of above-47bit hint address and PMD alignment mm/huge_memory.c: thp: fix conflict of above-47bit hint address and PMD alignment mm/memory_hotplug: don't free usage map when removing a re-added early section mm, thp: tweak reclaim/compaction effort of local-only and all-node allocations
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Mike Rapoport authored
The commit d96885e2 ("parisc: use pgtable-nopXd instead of 4level-fixup") converted PA-RISC to use folded page tables, but it missed the conversion of pgd_populate() to pud_populate() in maps_pages() function. This caused the upper page table directory to remain empty and the system would crash as a result. Using pud_populate() that actually populates the page table instead of dummy pgd_populate() fixes the issue. Fixes: d96885e2 ("parisc: use pgtable-nopXd instead of 4level-fixup") Reported-by:
Meelis Roos <mroos@linux.ee> Reported-by:
Jeroen Roovers <jer@gentoo.org> Reported-by:
Mikulas Patocka <mpatocka@redhat.com> Tested-by:
Mike Rapoport <rppt@linux.ibm.com> Signed-off-by:
Helge Deller <deller@gmx.de>
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Krzysztof Kozlowski authored
resource_size_t should be printed with its own size-independent format to fix warnings when compiling on 64-bit platform (e.g. with COMPILE_TEST): arch/parisc/kernel/drivers.c: In function 'print_parisc_device': arch/parisc/kernel/drivers.c:892:9: warning: format '%p' expects argument of type 'void *', but argument 4 has type 'resource_size_t {aka unsigned int}' [-Wformat=] Signed-off-by:Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by:
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Linus Torvalds authored
Merge Intel Gen9 graphics fix from Akeem Abodunrin: "Insufficient control flow in certain data structures for some Intel Processors with Intel Processor Graphics may allow an unauthenticated user to potentially enable information disclosure via local access This provides mitigation for Gen9 hardware. Note that Gen8 is not impacted due to a previously implemented workaround. The mitigation involves using an existing hardware feature to forcibly clear down all EU state at each context switch" * tag 'Intel-CVE-2019-14615' of emailed bundle from Akeem G Abodunrin <akeem.g.abodunrin@intel.com>: drm/i915/gen9: Clear residual context state on context switch
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Yang Shi authored
Commit 99cb0dbd ("mm,thp: add read-only THP support for (non-shmem) FS") introduced a new khugepaged scan result: SCAN_PAGE_HAS_PRIVATE, but the corresponding description for trace events were not added. Link: http://lkml.kernel.org/r/1574793844-2914-1-git-send-email-yang.shi@linux.alibaba.com Fixes: 99cb0dbd ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by:
Yang Shi <yang.shi@linux.alibaba.com> Cc: Song Liu <songliubraving@fb.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Adrian Huang authored
When booting with amd_iommu=off, the following WARNING message appears: AMD-Vi: AMD IOMMU disabled on kernel command-line ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/workqueue.c:2772 flush_workqueue+0x42e/0x450 Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc3-amd-iommu #6 Hardware name: Lenovo ThinkSystem SR655-2S/7D2WRCZ000, BIOS D8E101L-1.00 12/05/2019 RIP: 0010:flush_workqueue+0x42e/0x450 Code: ff 0f 0b e9 7a fd ff ff 4d 89 ef e9 33 fe ff ff 0f 0b e9 7f fd ff ff 0f 0b e9 bc fd ff ff 0f 0b e9 a8 fd ff ff e8 52 2c fe ff <0f> 0b 31 d2 48 c7 c6 e0 88 c5 95 48 c7 c7 d8 ad f0 95 e8 19 f5 04 Call Trace: kmem_cache_destroy+0x69/0x260 iommu_go_to_state+0x40c/0x5ab amd_iommu_prepare+0x16/0x2a irq_remapping_prepare+0x36/0x5f enable_IR_x2apic+0x21/0x172 default_setup_apic_routing+0x12/0x6f apic_intr_mode_init+0x1a1/0x1f1 x86_late_time_init+0x17/0x1c start_kernel+0x480/0x53f secondary_startup_64+0xb6/0xc0 ---[ end trace 30894107c3749449 ]--- x2apic: IRQ remapping doesn't support X2APIC mode x2apic disabled The warning is caused by the calling of 'kmem_cache_destroy()' in free_iommu_resources(). Here is the call path: free_iommu_resources kmem_cache_destroy flush_memcg_workqueue flush_workqueue The root cause is that the IOMMU subsystem runs before the workqueue subsystem, which the variable 'wq_online' is still 'false'. This leads to the statement 'if (WARN_ON(!wq_online))' in flush_workqueue() is 'true'. Since the variable 'memcg_kmem_cache_wq' is not allocated during the time, it is unnecessary to call flush_memcg_workqueue(). This prevents the WARNING message triggered by flush_workqueue(). Link: http://lkml.kernel.org/r/20200103085503.1665-1-ahuang12@lenovo.com Fixes: 92ee383f ("mm: fix race between kmem_cache destroy, create and deactivate") Signed-off-by:Adrian Huang <ahuang12@lenovo.com> Reported-by:
Xiaochun Lee <lixc17@lenovo.com> Reviewed-by:
Shakeel Butt <shakeelb@google.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> Signed-off-by:
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Wen Yang authored
Use div64_ul() instead of do_div() if the divisor is unsigned long, to avoid truncation to 32-bit on 64-bit platforms. Link: http://lkml.kernel.org/r/20200102081442.8273-4-wenyang@linux.alibaba.comSigned-off-by:
Wen Yang <wenyang@linux.alibaba.com> Reviewed-by:
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Wen Yang authored
The two variables 'numerator' and 'denominator', though they are declared as long, they should actually be unsigned long (according to the implementation of the fprop_fraction_percpu() function) And do_div() does a 64-by-32 division, while the divisor 'denominator' is unsigned long, thus 64-bit on 64-bit platforms. Hence the proper function to call is div64_ul(). Link: http://lkml.kernel.org/r/20200102081442.8273-3-wenyang@linux.alibaba.comSigned-off-by:
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Wen Yang authored
Patch series "use div64_ul() instead of div_u64() if the divisor is unsigned long". We were first inspired by commit b0ab99e7 ("sched: Fix possible divide by zero in avg_atom () calculation"), then refer to the recently analyzed mm code, we found this suspicious place. 201 if (min) { 202 min *= this_bw; 203 do_div(min, tot_bw); 204 } And we also disassembled and confirmed it: /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 201 0xffffffff811c37da <__wb_calc_thresh+234>: xor %r10d,%r10d 0xffffffff811c37dd <__wb_calc_thresh+237>: test %rax,%rax 0xffffffff811c37e0 <__wb_calc_thresh+240>: je 0xffffffff811c3800 <__wb_calc_thresh+272> /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 202 0xffffffff811c37e2 <__wb_calc_thresh+242>: imul %r8,%rax /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 203 0xffffffff811c37e6 <__wb_calc_thresh+246>: mov %r9d,%r10d ---> truncates it to 32 bits here 0xffffffff811c37e9 <__wb_calc_thresh+249>: xor %edx,%edx 0xffffffff811c37eb <__wb_calc_thresh+251>: div %r10 0xffffffff811c37ee <__wb_calc_thresh+254>: imul %rbx,%rax 0xffffffff811c37f2 <__wb_calc_thresh+258>: shr $0x2,%rax 0xffffffff811c37f6 <__wb_calc_thresh+262>: mul %rcx 0xffffffff811c37f9 <__wb_calc_thresh+265>: shr $0x2,%rdx 0xffffffff811c37fd <__wb_calc_thresh+269>: mov %rdx,%r10 This series uses div64_ul() instead of div_u64() if the divisor is unsigned long, to avoid truncation to 32-bit on 64-bit platforms. This patch (of 3): The variables 'min' and 'max' are unsigned long and do_div truncates them to 32 bits, which means it can test non-zero and be truncated to zero for division. Fix this issue by using div64_ul() instead. Link: http://lkml.kernel.org/r/20200102081442.8273-2-wenyang@linux.alibaba.com Fixes: 693108a8 ("writeback: make bdi->min/max_ratio handling cgroup writeback aware") Signed-off-by:
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Vlastimil Babka authored
Commit 96a2b03f ("mm, debug_pagelloc: use static keys to enable debugging") has introduced a static key to reduce overhead when debug_pagealloc is compiled in but not enabled. It relied on the assumption that jump_label_init() is called before parse_early_param() as in start_kernel(), so when the "debug_pagealloc=on" option is parsed, it is safe to enable the static key. However, it turns out multiple architectures call parse_early_param() earlier from their setup_arch(). x86 also calls jump_label_init() even earlier, so no issue was found while testing the commit, but same is not true for e.g. ppc64 and s390 where the kernel would not boot with debug_pagealloc=on as found by our QA. To fix this without tricky changes to init code of multiple architectures, this patch partially reverts the static key conversion from 96a2b03f. Init-time and non-fastpath calls (such as in arch code) of debug_pagealloc_enabled() will again test a simple bool variable. Fastpath mm code is converted to a new debug_pagealloc_enabled_static() variant that relies on the static key, which is enabled in a well-defined point in mm_init() where it's guaranteed that jump_label_init() has been called, regardless of architecture. [sfr@canb.auug.org.au: export _debug_pagealloc_enabled_early] Link: http://lkml.kernel.org/r/20200106164944.063ac07b@canb.auug.org.au Link: http://lkml.kernel.org/r/20191219130612.23171-1-vbabka@suse.cz Fixes: 96a2b03f ("mm, debug_pagelloc: use static keys to enable debugging") Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Qian Cai <cai@lca.pw> Cc: <stable@vger.kernel.org> Signed-off-by:
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Roman Gushchin authored
Currently slab percpu vmstats are flushed twice: during the memcg offlining and just before freeing the memcg structure. Each time percpu counters are summed, added to the atomic counterparts and propagated up by the cgroup tree. The second flushing is required due to how recursive vmstats are implemented: counters are batched in percpu variables on a local level, and once a percpu value is crossing some predefined threshold, it spills over to atomic values on the local and each ascendant levels. It means that without flushing some numbers cached in percpu variables will be dropped on floor each time a cgroup is destroyed. And with uptime the error on upper levels might become noticeable. The first flushing aims to make counters on ancestor levels more precise. Dying cgroups may resume in the dying state for a long time. After kmem_cache reparenting which is performed during the offlining slab counters of the dying cgroup don't have any chances to be updated, because any slab operations will be performed on the parent level. It means that the inaccuracy caused by percpu batching will not decrease up to the final destruction of the cgroup. By the original idea flushing slab counters during the offlining should minimize the visible inaccuracy of slab counters on the parent level. The problem is that percpu counters are not zeroed after the first flushing. So every cached percpu value is summed twice. It creates a small error (up to 32 pages per cpu, but usually less) which accumulates on parent cgroup level. After creating and destroying of thousands of child cgroups, slab counter on parent level can be way off the real value. For now, let's just stop flushing slab counters on memcg offlining. It can't be done correctly without scheduling a work on each cpu: reading and zeroing it during css offlining can race with an asynchronous update, which doesn't expect values to be changed underneath. With this change, slab counters on parent level will become eventually consistent. Once all dying children are gone, values are correct. And if not, the error is capped by 32 * NR_CPUS pages per dying cgroup. It's not perfect, as slab are reparented, so any updates after the reparenting will happen on the parent level. It means that if a slab page was allocated, a counter on child level was bumped, then the page was reparented and freed, the annihilation of positive and negative counter values will not happen until the child cgroup is released. It makes slab counters different from others, and it might want us to implement flushing in a correct form again. But it's also a question of performance: scheduling a work on each cpu isn't free, and it's an open question if the benefit of having more accurate counters is worth it. We might also consider flushing all counters on offlining, not only slab counters. So let's fix the main problem now: make the slab counters eventually consistent, so at least the error won't grow with uptime (or more precisely the number of created and destroyed cgroups). And think about the accuracy of counters separately. Link: http://lkml.kernel.org/r/20191220042728.1045881-1-guro@fb.com Fixes: bee07b33 ("mm: memcontrol: flush percpu slab vmstats on kmem offlining") Signed-off-by:
Roman Gushchin <guro@fb.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Kirill A. Shutemov authored
Shmem/tmpfs tries to provide THP-friendly mappings if huge pages are enabled. But it doesn't work well with above-47bit hint address. Normally, the kernel doesn't create userspace mappings above 47-bit, even if the machine allows this (such as with 5-level paging on x86-64). Not all user space is ready to handle wide addresses. It's known that at least some JIT compilers use higher bits in pointers to encode their information. Userspace can ask for allocation from full address space by specifying hint address (with or without MAP_FIXED) above 47-bits. If the application doesn't need a particular address, but wants to allocate from whole address space it can specify -1 as a hint address. Unfortunately, this trick breaks THP alignment in shmem/tmp: shmem_get_unmapped_area() would not try to allocate PMD-aligned area if *any* hint address specified. This can be fixed by requesting the aligned area if the we failed to allocated at user-specified hint address. The request with inflated length will also take the user-specified hint address. This way we will not lose an allocation request from the full address space. [kirill@shutemov.name: fold in a fixup] Link: http://lkml.kernel.org/r/20191223231309.t6bh5hkbmokihpfu@box Link: http://lkml.kernel.org/r/20191220142548.7118-3-kirill.shutemov@linux.intel.com Fixes: b569bab7 ("x86/mm: Prepare to expose larger address space to userspace") Signed-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Willhalm, Thomas" <thomas.willhalm@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "Bruggeman, Otto G" <otto.g.bruggeman@intel.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Kirill A. Shutemov authored
Patch series "Fix two above-47bit hint address vs. THP bugs". The two get_unmapped_area() implementations have to be fixed to provide THP-friendly mappings if above-47bit hint address is specified. This patch (of 2): Filesystems use thp_get_unmapped_area() to provide THP-friendly mappings. For DAX in particular. Normally, the kernel doesn't create userspace mappings above 47-bit, even if the machine allows this (such as with 5-level paging on x86-64). Not all user space is ready to handle wide addresses. It's known that at least some JIT compilers use higher bits in pointers to encode their information. Userspace can ask for allocation from full address space by specifying hint address (with or without MAP_FIXED) above 47-bits. If the application doesn't need a particular address, but wants to allocate from whole address space it can specify -1 as a hint address. Unfortunately, this trick breaks thp_get_unmapped_area(): the function would not try to allocate PMD-aligned area if *any* hint address specified. Modify the routine to handle it correctly: - Try to allocate the space at the specified hint address with length padding required for PMD alignment. - If failed, retry without length padding (but with the same hint address); - If the returned address matches the hint address return it. - Otherwise, align the address as required for THP and return. The user specified hint address is passed down to get_unmapped_area() so above-47bit hint address will be taken into account without breaking alignment requirements. Link: http://lkml.kernel.org/r/20191220142548.7118-2-kirill.shutemov@linux.intel.com Fixes: b569bab7 ("x86/mm: Prepare to expose larger address space to userspace") Signed-off-by:
Thomas Willhalm <thomas.willhalm@intel.com> Tested-by:
Dan Williams <dan.j.williams@intel.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Bruggeman, Otto G" <otto.g.bruggeman@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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