- 31 Jan, 2020 39 commits
-
-
John Hubbard authored
Convert fs/io_uring to use the new pin_user_pages() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages, and therefore for any code that calls put_user_page(). In partial anticipation of this work, the io_uring code was already calling put_user_page() instead of put_page(). Therefore, in order to convert from the get_user_pages()/put_page() model, to the pin_user_pages()/put_user_page() model, the only change required here is to change get_user_pages() to pin_user_pages(). Link: http://lkml.kernel.org/r/20200107224558.2362728-17-jhubbard@nvidia.comSigned-off-by:
John Hubbard <jhubbard@nvidia.com> Reviewed-by:
Jens Axboe <axboe@kernel.dk> Reviewed-by:
Jan Kara <jack@suse.cz> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
John Hubbard authored
Convert drm/via to use the new pin_user_pages_fast() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages, and therefore for any code that calls put_user_page(). In partial anticipation of this work, the drm/via driver was already calling put_user_page() instead of put_page(). Therefore, in order to convert from the get_user_pages()/put_page() model, to the pin_user_pages()/put_user_page() model, the only change required is to change get_user_pages() to pin_user_pages(). Link: http://lkml.kernel.org/r/20200107224558.2362728-16-jhubbard@nvidia.comSigned-off-by:
Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by:
Jérôme Glisse <jglisse@redhat.com> Reviewed-by:
Ira Weiny <ira.weiny@intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by:
-
John Hubbard authored
Convert process_vm_access to use the new pin_user_pages_remote() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages. Also, release the pages via put_user_page*(). Also, rename "pages" to "pinned_pages", as this makes for easier reading of process_vm_rw_single_vec(). Link: http://lkml.kernel.org/r/20200107224558.2362728-15-jhubbard@nvidia.comSigned-off-by:
-
John Hubbard authored
Convert infiniband to use the new pin_user_pages*() calls. Also, revert earlier changes to Infiniband ODP that had it using put_user_page(). ODP is "Case 3" in Documentation/core-api/pin_user_pages.rst, which is to say, normal get_user_pages() and put_page() is the API to use there. The new pin_user_pages*() calls replace corresponding get_user_pages*() calls, and set the FOLL_PIN flag. The FOLL_PIN flag requires that the caller must return the pages via put_user_page*() calls, but infiniband was already doing that as part of an earlier commit. Link: http://lkml.kernel.org/r/20200107224558.2362728-14-jhubbard@nvidia.comSigned-off-by:
Jason Gunthorpe <jgg@mellanox.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by:
-
John Hubbard authored
1. Call the new global pin_user_pages_fast(), from pin_goldfish_pages(). 2. As required by pin_user_pages(), release these pages via put_user_page(). In this case, do so via put_user_pages_dirty_lock(). That has the side effect of calling set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] Another side effect is that the release code is simplified because the page[] loop is now in gup.c instead of here, so just delete the local release_user_pages() entirely, and call put_user_pages_dirty_lock() directly, instead. [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Link: http://lkml.kernel.org/r/20200107224558.2362728-13-jhubbard@nvidia.comSigned-off-by:
-
John Hubbard authored
Introduce pin_user_pages*() variations of get_user_pages*() calls, and also pin_longterm_pages*() variations. For now, these are placeholder calls, until the various call sites are converted to use the correct get_user_pages*() or pin_user_pages*() API. These variants will eventually all set FOLL_PIN, which is also introduced, and thoroughly documented. pin_user_pages() pin_user_pages_remote() pin_user_pages_fast() All pages that are pinned via the above calls, must be unpinned via put_user_page(). The underlying rules are: * FOLL_PIN is a gup-internal flag, so the call sites should not directly set it. That behavior is enforced with assertions. * Call sites that want to indicate that they are going to do DirectIO ("DIO") or something with similar characteristics, should call a get_user_pages()-like wrapper call that sets FOLL_PIN. These wrappers will: * Start with "pin_user_pages" instead of "get_user_pages". That makes it easy to find and audit the call sites. * Set FOLL_PIN * For pages that are received via FOLL_PIN, those pages must be returned via put_user_page(). Thanks to Jan Kara and Vlastimil Babka for explaining the 4 cases in this documentation. (I've reworded it and expanded upon it.) Link: http://lkml.kernel.org/r/20200107224558.2362728-12-jhubbard@nvidia.comSigned-off-by: -
John Hubbard authored
After DMA is complete, and the device and CPU caches are synchronized, it's still required to mark the CPU pages as dirty, if the data was coming from the device. However, this driver was just issuing a bare put_page() call, without any set_page_dirty*() call. Fix the problem, by calling set_page_dirty_lock() if the CPU pages were potentially receiving data from the device. Link: http://lkml.kernel.org/r/20200107224558.2362728-11-jhubbard@nvidia.comSigned-off-by:
Christoph Hellwig <hch@lst.de> Acked-by:
Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: <stable@vger.kernel.org> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by:
-
John Hubbard authored
And get rid of the mmap_sem calls, as part of that. Note that get_user_pages_fast() will, if necessary, fall back to __gup_longterm_unlocked(), which takes the mmap_sem as needed. Link: http://lkml.kernel.org/r/20200107224558.2362728-10-jhubbard@nvidia.comSigned-off-by:
Leon Romanovsky <leonro@mellanox.com> Reviewed-by:
-
John Hubbard authored
Commit 817be129 ("mm: validate get_user_pages_fast flags") allowed only FOLL_WRITE and FOLL_LONGTERM to be passed to get_user_pages_fast(). This, combined with the fact that get_user_pages_fast() falls back to "slow gup", which *does* accept FOLL_FORCE, leads to an odd situation: if you need FOLL_FORCE, you cannot call get_user_pages_fast(). There does not appear to be any reason for filtering out FOLL_FORCE. There is nothing in the _fast() implementation that requires that we avoid writing to the pages. So it appears to have been an oversight. Fix by allowing FOLL_FORCE to be set for get_user_pages_fast(). Link: http://lkml.kernel.org/r/20200107224558.2362728-9-jhubbard@nvidia.com Fixes: 817be129 ("mm: validate get_user_pages_fast flags") Signed-off-by:
-
John Hubbard authored
Update VFIO to take advantage of the recently loosened restriction on FOLL_LONGTERM with get_user_pages_remote(). Also, now it is possible to fix a bug: the VFIO caller is logically a FOLL_LONGTERM user, but it wasn't setting FOLL_LONGTERM. Also, remove an unnessary pair of calls that were releasing and reacquiring the mmap_sem. There is no need to avoid holding mmap_sem just in order to call page_to_pfn(). Also, now that the the DAX check ("if a VMA is DAX, don't allow long term pinning") is in the internals of get_user_pages_remote() and __gup_longterm_locked(), there's no need for it at the VFIO call site. So remove it. Link: http://lkml.kernel.org/r/20200107224558.2362728-8-jhubbard@nvidia.comSigned-off-by:Alex Williamson <alex.williamson@redhat.com> Acked-by:
Jason Gunthorpe <jgg@ziepe.ca> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by:
-
John Hubbard authored
As it says in the updated comment in gup.c: current FOLL_LONGTERM behavior is incompatible with FAULT_FLAG_ALLOW_RETRY because of the FS DAX check requirement on vmas. However, the corresponding restriction in get_user_pages_remote() was slightly stricter than is actually required: it forbade all FOLL_LONGTERM callers, but we can actually allow FOLL_LONGTERM callers that do not set the "locked" arg. Update the code and comments to loosen the restriction, allowing FOLL_LONGTERM in some cases. Also, copy the DAX check ("if a VMA is DAX, don't allow long term pinning") from the VFIO call site, all the way into the internals of get_user_pages_remote() and __gup_longterm_locked(). That is: get_user_pages_remote() calls __gup_longterm_locked(), which in turn calls check_dax_vmas(). This check will then be removed from the VFIO call site in a subsequent patch. Thanks to Jason Gunthorpe for pointing out a clean way to fix this, and to Dan Williams for helping clarify the DAX refactoring. Link: http://lkml.kernel.org/r/20200107224558.2362728-7-jhubbard@nvidia.comSigned-off-by: -
John Hubbard authored
Avoid naming conflicts: rename local static function from "pin_user_pages()" to "goldfish_pin_pages()". An upcoming patch will introduce a global pin_user_pages() function. Link: http://lkml.kernel.org/r/20200107224558.2362728-6-jhubbard@nvidia.comSigned-off-by:
-
John Hubbard authored
An upcoming patch changes and complicates the refcounting and especially the "put page" aspects of it. In order to keep everything clean, refactor the devmap page release routines: * Rename put_devmap_managed_page() to page_is_devmap_managed(), and limit the functionality to "read only": return a bool, with no side effects. * Add a new routine, put_devmap_managed_page(), to handle decrementing the refcount for ZONE_DEVICE pages. * Change callers (just release_pages() and put_page()) to check page_is_devmap_managed() before calling the new put_devmap_managed_page() routine. This is a performance point: put_page() is a hot path, so we need to avoid non- inline function calls where possible. * Rename __put_devmap_managed_page() to free_devmap_managed_page(), and limit the functionality to unconditionally freeing a devmap page. This is originally based on a separate patch by Ira Weiny, which applied to an early version of the put_user_page() experiments. Since then, Jérôme Glisse suggested the refactoring described above. Link: http://lkml.kernel.org/r/20200107224558.2362728-5-jhubbard@nvidia.comSigned-off-by:
Dan Williams <dan.j.williams@intel.com> Reviewed-by:
-
Dan Williams authored
After the removal of the device-public infrastructure there are only 2 ->page_free() call backs in the kernel. One of those is a device-private callback in the nouveau driver, the other is a generic wakeup needed in the DAX case. In the hopes that all ->page_free() callbacks can be migrated to common core kernel functionality, move the device-private specific actions in __put_devmap_managed_page() under the is_device_private_page() conditional, including the ->page_free() callback. For the other page types just open-code the generic wakeup. Yes, the wakeup is only needed in the MEMORY_DEVICE_FSDAX case, but it does no harm in the MEMORY_DEVICE_DEVDAX and MEMORY_DEVICE_PCI_P2PDMA case. Link: http://lkml.kernel.org/r/20200107224558.2362728-4-jhubbard@nvidia.comSigned-off-by:
-
John Hubbard authored
An upcoming patch uses try_get_compound_head() more widely, so move it to the top of gup.c. Also fix a tiny spelling error and a checkpatch.pl warning. Link: http://lkml.kernel.org/r/20200107224558.2362728-3-jhubbard@nvidia.comSigned-off-by:
-
John Hubbard authored
Patch series "mm/gup: prereqs to track dma-pinned pages: FOLL_PIN", v12. Overview: This is a prerequisite to solving the problem of proper interactions between file-backed pages, and [R]DMA activities, as discussed in [1], [2], [3], and in a remarkable number of email threads since about 2017. :) A new internal gup flag, FOLL_PIN is introduced, and thoroughly documented in the last patch's Documentation/vm/pin_user_pages.rst. I believe that this will provide a good starting point for doing the layout lease work that Ira Weiny has been working on. That's because these new wrapper functions provide a clean, constrained, systematically named set of functionality that, again, is required in order to even know if a page is "dma-pinned". In contrast to earlier approaches, the page tracking can be incrementally applied to the kernel call sites that, until now, have been simply calling get_user_pages() ("gup"). In other words, opt-in by changing from this: get_user_pages() (sets FOLL_GET) put_page() to this: pin_user_pages() (sets FOLL_PIN) unpin_user_page() Testing: * I've done some overall kernel testing (LTP, and a few other goodies), and some directed testing to exercise some of the changes. And as you can see, gup_benchmark is enhanced to exercise this. Basically, I've been able to runtime test the core get_user_pages() and pin_user_pages() and related routines, but not so much on several of the call sites--but those are generally just a couple of lines changed, each. Not much of the kernel is actually using this, which on one hand reduces risk quite a lot. But on the other hand, testing coverage is low. So I'd love it if, in particular, the Infiniband and PowerPC folks could do a smoke test of this series for me. Runtime testing for the call sites so far is pretty light: * io_uring: Some directed tests from liburing exercise this, and they pass. * process_vm_access.c: A small directed test passes. * gup_benchmark: the enhanced version hits the new gup.c code, and passes. * infiniband: Ran rdma-core tests: rdma-core/build/bin/run_tests.py * VFIO: compiles (I'm vowing to set up a run time test soon, but it's not ready just yet) * powerpc: it compiles... * drm/via: compiles... * goldfish: compiles... * net/xdp: compiles... * media/v4l2: compiles... [1] Some slow progress on get_user_pages() (Apr 2, 2019): https://lwn.net/Articles/784574/ [2] DMA and get_user_pages() (LPC: Dec 12, 2018): https://lwn.net/Articles/774411/ [3] The trouble with get_user_pages() (Apr 30, 2018): https://lwn.net/Articles/753027/ This patch (of 22): There are four locations in gup.c that have a fair amount of code duplication. This means that changing one requires making the same changes in four places, not to mention reading the same code four times, and wondering if there are subtle differences. Factor out the common code into static functions, thus reducing the overall line count and the code's complexity. Also, take the opportunity to slightly improve the efficiency of the error cases, by doing a mass subtraction of the refcount, surrounded by get_page()/put_page(). Also, further simplify (slightly), by waiting until the the successful end of each routine, to increment *nr. Link: http://lkml.kernel.org/r/20200107224558.2362728-2-jhubbard@nvidia.comSigned-off-by: -
Wei Yang authored
No functional change, just leverage the helper function to improve readability as others. Link: http://lkml.kernel.org/r/20200113070322.26627-1-richardw.yang@linux.intel.comSigned-off-by:
Wei Yang <richardw.yang@linux.intel.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Acked-by:
David Rientjes <rientjes@google.com> Reviewed-by:
Ralph Campbell <rcampbell@nvidia.com> Signed-off-by:
-
Qiujun Huang authored
sorry for not processing for a long time. I met it again. patch v1 https://lkml.org/lkml/2019/9/20/656 do_machine_check() do_memory_failure() memory_failure() hw_poison_user_mappings() try_to_unmap() pteval = swp_entry_to_pte(make_hwpoison_entry(subpage)); ...and now we have a swap entry that indicates that the page entry refers to a bad (and poisoned) page of memory, but gup_fast() at this level of the page table was ignoring swap entries, and incorrectly assuming that "!pxd_none() == valid and present". And this was not just a poisoned page problem, but a generaly swap entry problem. So, any swap entry type (device memory migration, numa migration, or just regular swapping) could lead to the same problem. Fix this by checking for pxd_present(), instead of pxd_none(). Link: http://lkml.kernel.org/r/1578479084-15508-1-git-send-email-hqjagain@gmail.comSigned-off-by:
Qiujun Huang <hqjagain@gmail.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by:
-
Ira Weiny authored
At some point filemap_write_and_wait() and filemap_write_and_wait_range() got the exact same implementation with the exception of the range being specified in *_range() Similar to other functions in fs.h which call *_range(..., 0, LLONG_MAX), change filemap_write_and_wait() to be a static inline which calls filemap_write_and_wait_range() Link: http://lkml.kernel.org/r/20191129160713.30892-1-ira.weiny@intel.comSigned-off-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:
-
Vlastimil Babka authored
Commit 76a1850e ("mm/debug.c: __dump_page() prints an extra line") inadvertently removed printing of page flags for pages that are neither anon nor ksm nor have a mapping. Fix that. Using pr_cont() again would be a solution, but the commit explicitly removed its use. Avoiding the danger of mixing up split lines from multiple CPUs might be beneficial for near-panic dumps like this, so fix this without reintroducing pr_cont(). Link: http://lkml.kernel.org/r/9f884d5c-ca60-dc7b-219c-c081c755fab6@suse.cz Fixes: 76a1850e ("mm/debug.c: __dump_page() prints an extra line") Signed-off-by:
Anshuman Khandual <anshuman.khandual@arm.com> Reported-by:
Michal Hocko <mhocko@kernel.org> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Qian Cai <cai@lca.pw> Cc: Oscar Salvador <osalvador@suse.de> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by:
-
He Zhe authored
kmemleak_lock as a rwlock on RT can possibly be acquired in atomic context which does work. Since the kmemleak operation is performed in atomic context make it a raw_spinlock_t so it can also be acquired on RT. This is used for debugging and is not enabled by default in a production like environment (where performance/latency matters) so it makes sense to make it a raw_spinlock_t instead trying to get rid of the atomic context. Turn also the kmemleak_object->lock into raw_spinlock_t which is acquired (nested) while the kmemleak_lock is held. The time spent in "echo scan > kmemleak" slightly improved on 64core box with this patch applied after boot. [bigeasy@linutronix.de: redo the description, update comments. Merge the individual bits: He Zhe did the kmemleak_lock, Liu Haitao the ->lock and Yongxin Liu forwarded Liu's patch.] Link: http://lkml.kernel.org/r/20191219170834.4tah3prf2gdothz4@linutronix.de Link: https://lkml.kernel.org/r/20181218150744.GB20197@arrakis.emea.arm.com Link: https://lkml.kernel.org/r/1542877459-144382-1-git-send-email-zhe.he@windriver.com Link: https://lkml.kernel.org/r/20190927082230.34152-1-yongxin.liu@windriver.comSigned-off-by:
He Zhe <zhe.he@windriver.com> Signed-off-by:
Liu Haitao <haitao.liu@windriver.com> Signed-off-by:
Yongxin Liu <yongxin.liu@windriver.com> Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by:
Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
-
Yu Zhao authored
If we are already under list_lock, don't call kmalloc(). Otherwise we will run into a deadlock because kmalloc() also tries to grab the same lock. Fix the problem by using a static bitmap instead. WARNING: possible recursive locking detected -------------------------------------------- mount-encrypted/4921 is trying to acquire lock: (&(&n->list_lock)->rlock){-.-.}, at: ___slab_alloc+0x104/0x437 but task is already holding lock: (&(&n->list_lock)->rlock){-.-.}, at: __kmem_cache_shutdown+0x81/0x3cb other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&n->list_lock)->rlock); lock(&(&n->list_lock)->rlock); *** DEADLOCK *** Link: http://lkml.kernel.org/r/20191108193958.205102-2-yuzhao@google.comSigned-off-by:Yu Zhao <yuzhao@google.com> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> 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: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by:
-
wangyan authored
For the uniform format, we use ocfs2_update_inode_fsync_trans() to access t_tid in handle->h_transaction Link: http://lkml.kernel.org/r/6ff9a312-5f7d-0e27-fb51-bc4e062fcd97@huawei.comSigned-off-by:
Yan Wang <wangyan122@huawei.com> Reviewed-by:
Jun Piao <piaojun@huawei.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Signed-off-by:
-
wangyan authored
I found a NULL pointer dereference in ocfs2_update_inode_fsync_trans(), handle->h_transaction may be NULL in this situation: ocfs2_file_write_iter ->__generic_file_write_iter ->generic_perform_write ->ocfs2_write_begin ->ocfs2_write_begin_nolock ->ocfs2_write_cluster_by_desc ->ocfs2_write_cluster ->ocfs2_mark_extent_written ->ocfs2_change_extent_flag ->ocfs2_split_extent ->ocfs2_try_to_merge_extent ->ocfs2_extend_rotate_transaction ->ocfs2_extend_trans ->jbd2_journal_restart ->jbd2__journal_restart // handle->h_transaction is NULL here ->handle->h_transaction = NULL; ->start_this_handle /* journal aborted due to storage network disconnection, return error */ ->return -EROFS; /* line 3806 in ocfs2_try_to_merge_extent (), it will ignore ret error. */ ->ret = 0; ->... ->ocfs2_write_end ->ocfs2_write_end_nolock ->ocfs2_update_inode_fsync_trans // NULL pointer dereference ->oi->i_sync_tid = handle->h_transaction->t_tid; The information of NULL pointer dereference as follows: JBD2: Detected IO errors while flushing file data on dm-11-45 Aborting journal on device dm-11-45. JBD2: Error -5 detected when updating journal superblock for dm-11-45. (dd,22081,3):ocfs2_extend_trans:474 ERROR: status = -30 (dd,22081,3):ocfs2_try_to_merge_extent:3877 ERROR: status = -30 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Mem abort info: ESR = 0x96000004 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000e74e1338 [0000000000000008] pgd=0000000000000000 Internal error: Oops: 96000004 [#1] SMP Process dd (pid: 22081, stack limit = 0x00000000584f35a9) CPU: 3 PID: 22081 Comm: dd Kdump: loaded Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019 pstate: 60400009 (nZCv daif +PAN -UAO) pc : ocfs2_write_end_nolock+0x2b8/0x550 [ocfs2] lr : ocfs2_write_end_nolock+0x2a0/0x550 [ocfs2] sp : ffff0000459fba70 x29: ffff0000459fba70 x28: 0000000000000000 x27: ffff807ccf7f1000 x26: 0000000000000001 x25: ffff807bdff57970 x24: ffff807caf1d4000 x23: ffff807cc79e9000 x22: 0000000000001000 x21: 000000006c6cd000 x20: ffff0000091d9000 x19: ffff807ccb239db0 x18: ffffffffffffffff x17: 000000000000000e x16: 0000000000000007 x15: ffff807c5e15bd78 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000001 x9 : 0000000000000228 x8 : 000000000000000c x7 : 0000000000000fff x6 : ffff807a308ed6b0 x5 : ffff7e01f10967c0 x4 : 0000000000000018 x3 : d0bc661572445600 x2 : 0000000000000000 x1 : 000000001b2e0200 x0 : 0000000000000000 Call trace: ocfs2_write_end_nolock+0x2b8/0x550 [ocfs2] ocfs2_write_end+0x4c/0x80 [ocfs2] generic_perform_write+0x108/0x1a8 __generic_file_write_iter+0x158/0x1c8 ocfs2_file_write_iter+0x668/0x950 [ocfs2] __vfs_write+0x11c/0x190 vfs_write+0xac/0x1c0 ksys_write+0x6c/0xd8 __arm64_sys_write+0x24/0x30 el0_svc_common+0x78/0x130 el0_svc_handler+0x38/0x78 el0_svc+0x8/0xc To prevent NULL pointer dereference in this situation, we use is_handle_aborted() before using handle->h_transaction->t_tid. Link: http://lkml.kernel.org/r/03e750ab-9ade-83aa-b000-b9e81e34e539@huawei.comSigned-off-by: -
Andy Shevchenko authored
There are users already and will be more of BITS_TO_BYTES() macro. Move it to bitops.h for wider use. In the case of ocfs2 the replacement is identical. As for bnx2x, there are two places where floor version is used. In the first case to calculate the amount of structures that can fit one memory page. In this case obviously the ceiling variant is correct and original code might have a potential bug, if amount of bits % 8 is not 0. In the second case the macro is used to calculate bytes transmitted in one microsecond. This will work for all speeds which is multiply of 1Gbps without any change, for the rest new code will give ceiling value, for instance 100Mbps will give 13 bytes, while old code gives 12 bytes and the arithmetically correct one is 12.5 bytes. Further the value is used to setup timer threshold which in any case has its own margins due to certain resolution. I don't see here an issue with slightly shifting thresholds for low speed connections, the card is supposed to utilize highest available rate, which is usually 10Gbps. Link: http://lkml.kernel.org/r/20200108121316.22411-1-andriy.shevchenko@linux.intel.comSigned-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by:
Joseph Qi <joseph.qi@linux.alibaba.com> Acked-by:
Sudarsana Reddy Kalluru <skalluru@marvell.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by:
-
Colin Ian King authored
The variable ret is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses Coverity ("Unused value") Link: http://lkml.kernel.org/r/20191202164833.62865-1-colin.king@canonical.comSigned-off-by:Colin Ian King <colin.king@canonical.com> Reviewed-by:
-
Masahiro Yamada authored
Gang He reports the failure of building fs/ocfs2/ as an external module of the kernel installed on the system: $ cd fs/ocfs2 $ make -C /lib/modules/`uname -r`/build M=`pwd` modules If you want to make it work reliably, I'd recommend to remove ccflags-y from the Makefiles, and to make header paths relative to the C files. I think this is the correct usage of the #include "..." directive. Link: http://lkml.kernel.org/r/20191227022950.14804-1-ghe@suse.comSigned-off-by:
Masahiro Yamada <masahiroy@kernel.org> Signed-off-by:
Gang He <ghe@suse.com> Reported-by:
-
zhengbin authored
Fixes coccicheck warnings: fs/ocfs2/cluster/quorum.c:76:2-3: Unneeded semicolon fs/ocfs2/dlmglue.c:573:2-3: Unneeded semicolon Link: http://lkml.kernel.org/r/6ee3aa16-9078-30b1-df3f-22064950bd98@linux.alibaba.comSigned-off-by:
zhengbin <zhengbin13@huawei.com> Reported-by:
Hulk Robot <hulkci@huawei.com> Acked-by:
-
Aditya Pakki authored
In the only caller of dlm_migrate_lockres() - dlm_empty_lockres(), target is checked for O2NM_MAX_NODES. Thus, the assertion in dlm_migrate_lockres() is unnecessary and can be removed. The patch eliminates such a check. Link: http://lkml.kernel.org/r/20191218194111.26041-1-pakki001@umn.eduSigned-off-by:
Aditya Pakki <pakki001@umn.edu> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by:
-
Luca Ceresoli authored
Add "issus" and correct it as "issues". Link: http://lkml.kernel.org/r/20200105221950.8384-1-luca@lucaceresoli.netSigned-off-by:
Luca Ceresoli <luca@lucaceresoli.net> Signed-off-by:
-
Xiong authored
Here are some of the common spelling mistakes and typos that I've found while fixing up spelling mistakes in the kernel. Most of them still exist in more than two source files. Link: http://lkml.kernel.org/r/20191229143626.51238-1-xndchn@gmail.comSigned-off-by:
Xiong <xndchn@gmail.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Chris Paterson <chris.paterson2@renesas.com> Signed-off-by:
-
Yang Shi authored
Since commit a49bd4d7 ("mm, numa: rework do_pages_move"), the semantic of move_pages() has changed to return the number of non-migrated pages if they were result of a non-fatal reasons (usually a busy page). This was an unintentional change that hasn't been noticed except for LTP tests which checked for the documented behavior. There are two ways to go around this change. We can even get back to the original behavior and return -EAGAIN whenever migrate_pages is not able to migrate pages due to non-fatal reasons. Another option would be to simply continue with the changed semantic and extend move_pages documentation to clarify that -errno is returned on an invalid input or when migration simply cannot succeed (e.g. -ENOMEM, -EBUSY) or the number of pages that couldn't have been migrated due to ephemeral reasons (e.g. page is pinned or locked for other reasons). This patch implements the second option because this behavior is in place for some time without anybody complaining and possibly new users depending on it. Also it allows to have a slightly easier error handling as the caller knows that it is worth to retry when err > 0. But since the new semantic would be aborted immediately if migration is failed due to ephemeral reasons, need include the number of non-attempted pages in the return value too. Link: http://lkml.kernel.org/r/1580160527-109104-1-git-send-email-yang.shi@linux.alibaba.com Fixes: a49bd4d7 ("mm, numa: rework do_pages_move") Signed-off-by:
Yang Shi <yang.shi@linux.alibaba.com> Suggested-by:
-
Wei Yang authored
If compound is true, this means it is a PMD mapped THP. Which implies the page is not linked to any defer list. So the first code chunk will not be executed. Also with this reason, it would not be proper to add this page to a defer list. So the second code chunk is not correct. Based on this, we should remove the defer list related code. [yang.shi@linux.alibaba.com: better patch title] Link: http://lkml.kernel.org/r/20200117233836.3434-1-richardw.yang@linux.intel.com Fixes: 87eaceb3 ("mm: thp: make deferred split shrinker memcg aware") Signed-off-by:
-
Dan Williams authored
The daxctl unit test for the dax_kmem driver currently triggers the (false positive) lockdep splat below. It results from the fact that remove_memory_block_devices() is invoked under the mem_hotplug_lock() causing lockdep entanglements with cpu_hotplug_lock() and sysfs (kernfs active state tracking). It is a false positive because the sysfs attribute path triggering the memory remove is not the same attribute path associated with memory-block device. sysfs_break_active_protection() is not applicable since there is no real deadlock conflict, instead move memory-block device removal outside the lock. The mem_hotplug_lock() is not needed to synchronize the memory-block device removal vs the page online state, that is already handled by lock_device_hotplug(). Specifically, lock_device_hotplug() is sufficient to allow try_remove_memory() to check the offline state of the memblocks and be assured that any in progress online attempts are flushed / blocked by kernfs_drain() / attribute removal. The add_memory() path safely creates memblock devices under the mem_hotplug_lock(). There is no kernfs active state synchronization in the memblock device_register() path, so nothing to fix there. This change is only possible thanks to the recent change that refactored memory block device removal out of arch_remove_memory() (commit 4c4b7f9b "mm/memory_hotplug: remove memory block devices before arch_remove_memory()"), and David's due diligence tracking down the guarantees afforded by kernfs_drain(). Not flagged for -stable since this only impacts ongoing development and lockdep validation, not a runtime issue. ====================================================== WARNING: possible circular locking dependency detected 5.5.0-rc3+ #230 Tainted: G OE ------------------------------------------------------ lt-daxctl/6459 is trying to acquire lock: ffff99c7f0003510 (kn->count#241){++++}, at: kernfs_remove_by_name_ns+0x41/0x80 but task is already holding lock: ffffffffa76a5450 (mem_hotplug_lock.rw_sem){++++}, at: percpu_down_write+0x20/0xe0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (mem_hotplug_lock.rw_sem){++++}: __lock_acquire+0x39c/0x790 lock_acquire+0xa2/0x1b0 get_online_mems+0x3e/0xb0 kmem_cache_create_usercopy+0x2e/0x260 kmem_cache_create+0x12/0x20 ptlock_cache_init+0x20/0x28 start_kernel+0x243/0x547 secondary_startup_64+0xb6/0xc0 -> #1 (cpu_hotplug_lock.rw_sem){++++}: __lock_acquire+0x39c/0x790 lock_acquire+0xa2/0x1b0 cpus_read_lock+0x3e/0xb0 online_pages+0x37/0x300 memory_subsys_online+0x17d/0x1c0 device_online+0x60/0x80 state_store+0x65/0xd0 kernfs_fop_write+0xcf/0x1c0 vfs_write+0xdb/0x1d0 ksys_write+0x65/0xe0 do_syscall_64+0x5c/0xa0 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (kn->count#241){++++}: check_prev_add+0x98/0xa40 validate_chain+0x576/0x860 __lock_acquire+0x39c/0x790 lock_acquire+0xa2/0x1b0 __kernfs_remove+0x25f/0x2e0 kernfs_remove_by_name_ns+0x41/0x80 remove_files.isra.0+0x30/0x70 sysfs_remove_group+0x3d/0x80 sysfs_remove_groups+0x29/0x40 device_remove_attrs+0x39/0x70 device_del+0x16a/0x3f0 device_unregister+0x16/0x60 remove_memory_block_devices+0x82/0xb0 try_remove_memory+0xb5/0x130 remove_memory+0x26/0x40 dev_dax_kmem_remove+0x44/0x6a [kmem] device_release_driver_internal+0xe4/0x1c0 unbind_store+0xef/0x120 kernfs_fop_write+0xcf/0x1c0 vfs_write+0xdb/0x1d0 ksys_write+0x65/0xe0 do_syscall_64+0x5c/0xa0 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: kn->count#241 --> cpu_hotplug_lock.rw_sem --> mem_hotplug_lock.rw_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(mem_hotplug_lock.rw_sem); lock(cpu_hotplug_lock.rw_sem); lock(mem_hotplug_lock.rw_sem); lock(kn->count#241); *** DEADLOCK *** No fixes tag as this has been a long standing issue that predated the addition of kernfs lockdep annotations. Link: http://lkml.kernel.org/r/157991441887.2763922.4770790047389427325.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
David Hildenbrand <david@redhat.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by:
-
Wei Yang authored
If we get here after successfully adding page to list, err would be 1 to indicate the page is queued in the list. Current code has two problems: * on success, 0 is not returned * on error, if add_page_for_migratioin() return 1, and the following err1 from do_move_pages_to_node() is set, the err1 is not returned since err is 1 And these behaviors break the user interface. Link: http://lkml.kernel.org/r/20200119065753.21694-1-richardw.yang@linux.intel.com Fixes: e0153fc2 ("mm: move_pages: return valid node id in status if the page is already on the target node"). Signed-off-by: -
Pingfan Liu authored
After commit ba72b4c8 ("mm/sparsemem: support sub-section hotplug"), when a mem section is fully deactivated, section_mem_map still records the section's start pfn, which is not used any more and will be reassigned during re-addition. In analogy with alloc/free pattern, it is better to clear all fields of section_mem_map. Beside this, it breaks the user space tool "makedumpfile" [1], which makes assumption that a hot-removed section has mem_map as NULL, instead of checking directly against SECTION_MARKED_PRESENT bit. (makedumpfile will be better to change the assumption, and need a patch) The bug can be reproduced on IBM POWERVM by "drmgr -c mem -r -q 5" , trigger a crash, and save vmcore by makedumpfile [1]: makedumpfile, commit e73016540293 ("[v1.6.7] Update version") Link: http://lkml.kernel.org/r/1579487594-28889-1-git-send-email-kernelfans@gmail.comSigned-off-by:
Pingfan Liu <kernelfans@gmail.com> Acked-by:
-
Dan Carpenter authored
What we are trying to do is change the '=' character to a NUL terminator and then at the end of the function we restore it back to an '='. The problem is there are two error paths where we jump to the end of the function before we have replaced the '=' with NUL. We end up putting the '=' in the wrong place (possibly one element before the start of the buffer). Link: http://lkml.kernel.org/r/20200115055426.vdjwvry44nfug7yy@kili.mountain Reported-by: syzbot+e64a13c5369a194d67df@syzkaller.appspotmail.com Fixes: 095f1fc4 ("mempolicy: rework shmem mpol parsing and display") Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Acked-by:
-
Theodore Ts'o authored
Without memcg, there is a one-to-one mapping between the bdi and bdi_writeback structures. In this world, things are fairly straightforward; the first thing bdi_unregister() does is to shutdown the bdi_writeback structure (or wb), and part of that writeback ensures that no other work queued against the wb, and that the wb is fully drained. With memcg, however, there is a one-to-many relationship between the bdi and bdi_writeback structures; that is, there are multiple wb objects which can all point to a single bdi. There is a refcount which prevents the bdi object from being released (and hence, unregistered). So in theory, the bdi_unregister() *should* only get called once its refcount goes to zero (bdi_put will drop the refcount, and when it is zero, release_bdi gets called, which calls bdi_unregister). Unfortunately, del_gendisk() in block/gen_hd.c never got the memo about the Brave New memcg World, and calls bdi_unregister directly. It does this without informing the file system, or the memcg code, or anything else. This causes the root wb associated with the bdi to be unregistered, but none of the memcg-specific wb's are shutdown. So when one of these wb's are woken up to do delayed work, they try to dereference their wb->bdi->dev to fetch the device name, but unfortunately bdi->dev is now NULL, thanks to the bdi_unregister() called by del_gendisk(). As a result, *boom*. Fortunately, it looks like the rest of the writeback path is perfectly happy with bdi->dev and bdi->owner being NULL, so the simplest fix is to create a bdi_dev_name() function which can handle bdi->dev being NULL. This also allows us to bulletproof the writeback tracepoints to prevent them from dereferencing a NULL pointer and crashing the kernel if one is tracing with memcg's enabled, and an iSCSI device dies or a USB storage stick is pulled. The most common way of triggering this will be hotremoval of a device while writeback with memcg enabled is going on. It was triggering several times a day in a heavily loaded production environment. Google Bug Id: 145475544 Link: https://lore.kernel.org/r/20191227194829.150110-1-tytso@mit.edu Link: http://lkml.kernel.org/r/20191228005211.163952-1-tytso@mit.eduSigned-off-by:
Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> Signed-off-by:
-
Andy Shevchenko authored
On 32-bit platform the size of long is only 32 bits which makes wrong offset in the array of 64 bit size. Calculate offset based on BITS_PER_LONG. Link: http://lkml.kernel.org/r/20200109103601.45929-1-andriy.shevchenko@linux.intel.com Fixes: 30544ed5 ("lib/bitmap: introduce bitmap_replace() helper") Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Yury Norov <yury.norov@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by:
-
- 30 Jan, 2020 1 commit
-
-
git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdmaLinus Torvalds authored
Pull mmu_notifier updates from Jason Gunthorpe: "This small series revises the names in mmu_notifier to make the code clearer and more readable" * tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier mm/mmu_notifiers: Use 'subscription' as the variable name for mmu_notifier mm/mmu_notifier: Rename struct mmu_notifier_mm to mmu_notifier_subscriptions
-
