- 11 Oct, 2019 1 commit
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git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull block fixes from Jens Axboe: - Fix wbt performance regression introduced with the blk-rq-qos refactoring (Harshad) - Fix io_uring fileset removal inadvertently killing the workqueue (me) - Fix io_uring typo in linked command nonblock submission (Pavel) - Remove spurious io_uring wakeups on request free (Pavel) - Fix null_blk zoned command error return (Keith) - Don't use freezable workqueues for backing_dev, also means we can revert a previous libata hack (Mika) - Fix nbd sysfs mutex dropped too soon at removal time (Xiubo) * tag 'for-linus-20191010' of git://git.kernel.dk/linux-block: nbd: fix possible sysfs duplicate warning null_blk: Fix zoned command return code io_uring: only flush workqueues on fileset removal io_uring: remove wait loop spurious wakeups blk-wbt: fix performance regression in wbt scale_up/scale_down Revert "libata, freezer: avoid block device removal while system is frozen" bdi: Do not use freezable workqueue io_uring: fix reversed nonblock flag for link submission
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- 10 Oct, 2019 11 commits
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git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds authored
Pull xfs fixes from Darrick Wong: "A couple of small code cleanups and bug fixes for rounding errors, metadata logging errors, and an extra layer of safeguards against leaking memory contents. - Fix a rounding error in the fallocate code - Minor code cleanups - Make sure to zero memory buffers before formatting metadata blocks - Fix a few places where we forgot to log an inode metadata update - Remove broken error handling that tried to clean up after a failure but still got it wrong" * tag 'xfs-5.4-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: move local to extent inode logging into bmap helper xfs: remove broken error handling on failed attr sf to leaf change xfs: log the inode on directory sf to block format change xfs: assure zeroed memory buffers for certain kmem allocations xfs: removed unused error variable from xchk_refcountbt_rec xfs: remove unused flags arg from xfs_get_aghdr_buf() xfs: Fix tail rounding in xfs_alloc_file_space() -
Xiubo Li authored
1. nbd_put takes the mutex and drops nbd->ref to 0. It then does idr_remove and drops the mutex. 2. nbd_genl_connect takes the mutex. idr_find/idr_for_each fails to find an existing device, so it does nbd_dev_add. 3. just before the nbd_put could call nbd_dev_remove or not finished totally, but if nbd_dev_add try to add_disk, we can hit: debugfs: Directory 'nbd1' with parent 'block' already present! This patch will make sure all the disk add/remove stuff are done by holding the nbd_index_mutex lock. Reported-by:
Mike Christie <mchristi@redhat.com> Reviewed-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
Xiubo Li <xiubli@redhat.com> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds authored
Pull crypto fixes from Herbert Xu: "Fix build issues in arm/aes-ce" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: arm/aes-ce - add dependency on AES library crypto: arm/aes-ce - build for v8 architecture explicitly
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linuxLinus Torvalds authored
Pull btrfs fixes from David Sterba: "A few more stabitly fixes, one build warning fix. - fix inode allocation under NOFS context - fix leak in fiemap due to concurrent append writes - fix log-root tree updates - fix balance convert of single profile on 32bit architectures - silence false positive warning on old GCCs (code moved in rc1)" * tag 'for-5.4-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: silence maybe-uninitialized warning in clone_range btrfs: fix uninitialized ret in ref-verify btrfs: allocate new inode in NOFS context btrfs: fix balance convert to single on 32-bit host CPUs btrfs: fix incorrect updating of log root tree Btrfs: fix memory leak due to concurrent append writes with fiemap
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds authored
Pull dcache_readdir() fixes from Al Viro: "The couple of patches you'd been OK with; no hlist conversion yet, and cursors are still in the list of children" [ Al is referring to future work to avoid some nasty O(n**2) behavior with the readdir cursors when you have lots of concurrent readdirs. This is just a fix for a race with a trivial cleanup - Linus ] * 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: libfs: take cursors out of list when moving past the end of directory Fix the locking in dcache_readdir() and friends
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds authored
Pull mount fixes from Al Viro: "A couple of regressions from the mount series" * 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: add missing blkdev_put() in get_tree_bdev() shmem: fix LSM options parsing
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Geert Uytterhoeven authored
At the end of the v5.3 upstream kernel development cycle, Simon stepped down from his role as Renesas SoC maintainer. Remove his maintainership, git repository, and branch from the MAINTAINERS file, and add an entry to the CREDITS file to honor his work. Signed-off-by:
Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Keith Busch authored
The return code from null_handle_zoned() sets the cmd->error value. Returning OK status when an error occured overwrites the intended cmd->error. Return the appropriate error code instead of setting the error in the cmd. Fixes: fceb5d1b ("null_blk: create a helper for zoned devices") Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by:
Keith Busch <kbusch@kernel.org> Signed-off-by:
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Al Viro authored
that eliminates the last place where we accessed the tail of ->d_subdirs Signed-off-by:Al Viro <viro@zeniv.linux.org.uk>
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Ian Kent authored
Is there are a couple of missing blkdev_put() in get_tree_bdev()? Signed-off-by: -
Al Viro authored
->parse_monolithic() there forgets to call security_sb_eat_lsm_opts() Signed-off-by:
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- 09 Oct, 2019 6 commits
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Jens Axboe authored
We should not remove the workqueue, we just need to ensure that the workqueues are synced. The workqueues are torn down on ctx removal. Cc: stable@vger.kernel.org Fixes: 6b06314c ("io_uring: add file set registration") Reported-by:
Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdmaLinus Torvalds authored
Pull rdma fixes from Jason Gunthorpe: "The usual collection of driver bug fixes, and a few regressions from the merge window. Nothing particularly worrisome. - Various missed memory frees and error unwind bugs - Fix regressions in a few iwarp drivers from 5.4 patches - A few regressions added in past kernels - Squash a number of races in mlx5 ODP code" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: RDMA/mlx5: Add missing synchronize_srcu() for MW cases RDMA/mlx5: Put live in the correct place for ODP MRs RDMA/mlx5: Order num_pending_prefetch properly with synchronize_srcu RDMA/odp: Lift umem_mutex out of ib_umem_odp_unmap_dma_pages() RDMA/mlx5: Fix a race with mlx5_ib_update_xlt on an implicit MR RDMA/mlx5: Do not allow rereg of a ODP MR IB/core: Fix wrong iterating on ports RDMA/nldev: Reshuffle the code to avoid need to rebind QP in error path RDMA/cxgb4: Do not dma memory off of the stack RDMA/cm: Fix memory leak in cm_add/remove_one RDMA/core: Fix an error handling path in 'res_get_common_doit()' RDMA/i40iw: Associate ibdev to netdev before IB device registration RDMA/iwcm: Fix a lock inversion issue RDMA/iw_cxgb4: fix SRQ access from dump_qp() RDMA/hfi1: Prevent memory leak in sdma_init RDMA/core: Fix use after free and refcnt leak on ndev in_device in iwarp_query_port RDMA/siw: Fix serialization issue in write_space() RDMA/vmw_pvrdma: Free SRQ only once
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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds authored
Pull arm64 fixes from Will Deacon: "A larger-than-usual batch of arm64 fixes for -rc3. The bulk of the fixes are dealing with a bunch of issues with the build system from the compat vDSO, which unfortunately led to some significant Makefile rework to manage the horrible combinations of toolchains that we can end up needing to drive simultaneously. We came close to disabling the thing entirely, but Vincenzo was quick to spin up some patches and I ended up picking up most of the bits that were left [*]. Future work will look at disentangling the header files properly. Other than that, we have some important fixes all over, including one papering over the miscompilation fallout from forcing CONFIG_OPTIMIZE_INLINING=y, which I'm still unhappy about. Harumph. We've still got a couple of open issues, so I'm expecting to have some more fixes later this cycle. Summary: - Numerous fixes to the compat vDSO build system, especially when combining gcc and clang - Fix parsing of PAR_EL1 in spurious kernel fault detection - Partial workaround for Neoverse-N1 erratum #1542419 - Fix IRQ priority masking on entry from compat syscalls - Fix advertisment of FRINT HWCAP to userspace - Attempt to workaround inlining breakage with '__always_inline' - Fix accidental freeing of parent SVE state on fork() error path - Add some missing NULL pointer checks in instruction emulation init - Some formatting and comment fixes" [*] Will's final fixes were Reviewed-by:Vincenzo Frascino <vincenzo.frascino@arm.com> Tested-by:
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Brian Foster authored
The callers of xfs_bmap_local_to_extents_empty() log the inode external to the function, yet this function is where the on-disk format value is updated. Push the inode logging down into the function itself to help prevent future mistakes. Note that internal bmap callers track the inode logging flags independently and thus may log the inode core twice due to this change. This is harmless, so leave this code around for consistency with the other attr fork conversion functions. Signed-off-by:
Brian Foster <bfoster@redhat.com> Reviewed-by:
Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by:
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Brian Foster authored
xfs_attr_shortform_to_leaf() attempts to put the shortform fork back together after a failed attempt to convert from shortform to leaf format. While this code reallocates and copies back the shortform attr fork data, it never resets the inode format field back to local format. Further, now that the inode is properly logged after the initial switch from local format, any error that triggers the recovery code will eventually abort the transaction and shutdown the fs. Therefore, remove the broken and unnecessary error handling code. Signed-off-by:
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Brian Foster authored
When a directory changes from shortform (sf) to block format, the sf format is copied to a temporary buffer, the inode format is modified and the updated format filled with the dentries from the temporary buffer. If the inode format is modified and attempt to grow the inode fails (due to I/O error, for example), it is possible to return an error while leaving the directory in an inconsistent state and with an otherwise clean transaction. This results in corruption of the associated directory and leads to xfs_dabuf_map() errors as subsequent lookups cannot accurately determine the format of the directory. This problem is reproduced occasionally by generic/475. The fundamental problem is that xfs_dir2_sf_to_block() changes the on-disk inode format without logging the inode. The inode is eventually logged by the bmapi layer in the common case, but error checking introduces the possibility of failing the high level request before this happens. Update both of the dir2 and attr callers of xfs_bmap_local_to_extents_empty() to log the inode core as consistent with the bmap local to extent format change codepath. This ensures that any subsequent errors after the format has changed cause the transaction to abort. Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
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- 08 Oct, 2019 9 commits
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Linus Torvalds authored
Merge tag 'led-fixes-for-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds Pull LED fixes from Jacek Anaszewski: - fix a leftover from earlier stage of development in the documentation of recently added led_compose_name() and fix old mistake in the documentation of led_set_brightness_sync() parameter name. - MAINTAINERS: add pointer to Pavel Machek's linux-leds.git tree. Pavel is going to take over LED tree maintainership from myself. * tag 'led-fixes-for-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds: Add my linux-leds branch to MAINTAINERS leds: core: Fix leds.h structure documentation
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Pavel Machek authored
Add pointer to my git tree to MAINTAINERS. I'd like to maintain linux-leds for-next branch for 5.5. Signed-off-by:
Pavel Machek <pavel@ucw.cz> Signed-off-by:
Jacek Anaszewski <jacek.anaszewski@gmail.com>
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Dan Murphy authored
Update the leds.h structure documentation to define the correct arguments. Signed-off-by:
Dan Murphy <dmurphy@ti.com> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpioLinus Torvalds authored
Pull GPIO fixes from Linus Walleij: - don't clear FLAG_IS_OUT when emulating open drain/source in gpiolib - fix up the usage of nonexclusive GPIO descriptors from device trees - fix the incorrect IEC offset when toggling trigger edge in the Spreadtrum driver - use the correct unit for debounce settings in the MAX77620 driver * tag 'gpio-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: gpio: max77620: Use correct unit for debounce times gpio: eic: sprd: Fix the incorrect EIC offset when toggling gpio: fix getting nonexclusive gpiods from DT gpiolib: don't clear FLAG_IS_OUT when emulating open-drain/open-source
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds authored
Pull selinuxfix from Paul Moore: "One patch to ensure we don't copy bad memory up into userspace" * tag 'selinux-pr-20191007' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: fix context string corruption in convert_context()
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Linus Torvalds authored
Merge tag 'linux-kselftest-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull Kselftest fixes from Shuah Khan: "Fixes for existing tests and the framework. Cristian Marussi's patches add the ability to skip targets (tests) and exclude tests that didn't build from run-list. These patches improve the Kselftest results. Ability to skip targets helps avoid running tests that aren't supported in certain environments. As an example, bpf tests from mainline aren't supported on stable kernels and have dependency on bleeding edge llvm. Being able to skip bpf on systems that can't meet this llvm dependency will be helpful. Kselftest can be built and installed from the main Makefile. This change help simplify Kselftest use-cases which addresses request from users. Kees Cook added per test timeout support to limit individual test run-time" * tag 'linux-kselftest-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: selftests: watchdog: Add command line option to show watchdog_info selftests: watchdog: Validate optional file argument selftests/kselftest/runner.sh: Add 45 second timeout per test kselftest: exclude failed TARGETS from runlist kselftest: add capability to skip chosen TARGETS selftests: Add kselftest-all and kselftest-install targets
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Yunfeng Ye authored
There are no return value checking when using kzalloc() and kcalloc() for memory allocation. so add it. Signed-off-by:
Yunfeng Ye <yeyunfeng@huawei.com> Signed-off-by:
Will Deacon <will@kernel.org>
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Austin Kim authored
GCC throws warning message as below: ‘clone_src_i_size’ may be used uninitialized in this function [-Wmaybe-uninitialized] #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) ^ fs/btrfs/send.c:5088:6: note: ‘clone_src_i_size’ was declared here u64 clone_src_i_size; ^ The clone_src_i_size is only used as call-by-reference in a call to get_inode_info(). Silence the warning by initializing clone_src_i_size to 0. Note that the warning is a false positive and reported by older versions of GCC (eg. 7.x) but not eg 9.x. As there have been numerous people, the patch is applied. Setting clone_src_i_size to 0 does not otherwise make sense and would not do any action in case the code changes in the future. Signed-off-by:Austin Kim <austindh.kim@gmail.com> Reviewed-by:
David Sterba <dsterba@suse.com> [ add note ] Signed-off-by:
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Pavel Begunkov authored
Any changes interesting to tasks waiting in io_cqring_wait() are commited with io_cqring_ev_posted(). However, io_ring_drop_ctx_refs() also tries to do that but with no reason, that means spurious wakeups every io_free_req() and io_uring_enter(). Just use percpu_ref_put() instead. Signed-off-by:
Pavel Begunkov <asml.silence@gmail.com> Signed-off-by:
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- 07 Oct, 2019 13 commits
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Linus Torvalds authored
Merge misc fixes from Andrew Morton: "The usual shower of hotfixes. Chris's memcg patches aren't actually fixes - they're mature but a few niggling review issues were late to arrive. The ocfs2 fixes are quite old - those took some time to get reviewer attention. Subsystems affected by this patch series: ocfs2, hotfixes, mm/memcg, mm/slab-generic" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two) mm, sl[ou]b: improve memory accounting mm, memcg: make scan aggression always exclude protection mm, memcg: make memory.emin the baseline for utilisation determination mm, memcg: proportional memory.{low,min} reclaim mm/vmpressure.c: fix a signedness bug in vmpressure_register_event() mm/page_alloc.c: fix a crash in free_pages_prepare() mm/z3fold.c: claim page in the beginning of free kernel/sysctl.c: do not override max_threads provided by userspace memcg: only record foreign writebacks with dirty pages when memcg is not disabled mm: fix -Wmissing-prototypes warnings writeback: fix use-after-free in finish_writeback_work() mm/memremap: drop unused SECTION_SIZE and SECTION_MASK panic: ensure preemption is disabled during panic() fs: ocfs2: fix a possible null-pointer dereference in ocfs2_info_scan_inode_alloc() fs: ocfs2: fix a possible null-pointer dereference in ocfs2_write_end_nolock() fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry() ocfs2: clear zero in unaligned direct IO -
Vlastimil Babka authored
In most configurations, kmalloc() happens to return naturally aligned (i.e. aligned to the block size itself) blocks for power of two sizes. That means some kmalloc() users might unknowingly rely on that alignment, until stuff breaks when the kernel is built with e.g. CONFIG_SLUB_DEBUG or CONFIG_SLOB, and blocks stop being aligned. Then developers have to devise workaround such as own kmem caches with specified alignment [1], which is not always practical, as recently evidenced in [2]. The topic has been discussed at LSF/MM 2019 [3]. Adding a 'kmalloc_aligned()' variant would not help with code unknowingly relying on the implicit alignment. For slab implementations it would either require creating more kmalloc caches, or allocate a larger size and only give back part of it. That would be wasteful, especially with a generic alignment parameter (in contrast with a fixed alignment to size). Ideally we should provide to mm users what they need without difficult workarounds or own reimplementations, so let's make the kmalloc() alignment to size explicitly guaranteed for power-of-two sizes under all configurations. What this means for the three available allocators? * SLAB object layout happens to be mostly unchanged by the patch. The implicitly provided alignment could be compromised with CONFIG_DEBUG_SLAB due to redzoning, however SLAB disables redzoning for caches with alignment larger than unsigned long long. Practically on at least x86 this includes kmalloc caches as they use cache line alignment, which is larger than that. Still, this patch ensures alignment on all arches and cache sizes. * SLUB layout is also unchanged unless redzoning is enabled through CONFIG_SLUB_DEBUG and boot parameter for the particular kmalloc cache. With this patch, explicit alignment is guaranteed with redzoning as well. This will result in more memory being wasted, but that should be acceptable in a debugging scenario. * SLOB has no implicit alignment so this patch adds it explicitly for kmalloc(). The potential downside is increased fragmentation. While pathological allocation scenarios are certainly possible, in my testing, after booting a x86_64 kernel+userspace with virtme, around 16MB memory was consumed by slab pages both before and after the patch, with difference in the noise. [1] https://lore.kernel.org/linux-btrfs/c3157c8e8e0e7588312b40c853f65c02fe6c957a.1566399731.git.christophe.leroy@c-s.fr/ [2] https://lore.kernel.org/linux-fsdevel/20190225040904.5557-1-ming.lei@redhat.com/ [3] https://lwn.net/Articles/787740/ [akpm@linux-foundation.org: documentation fixlet, per Matthew] Link: http://lkml.kernel.org/r/20190826111627.7505-3-vbabka@suse.czSigned-off-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Vlastimil Babka authored
Patch series "guarantee natural alignment for kmalloc()", v2. This patch (of 2): SLOB currently doesn't account its pages at all, so in /proc/meminfo the Slab field shows zero. Modifying a counter on page allocation and freeing should be acceptable even for the small system scenarios SLOB is intended for. Since reclaimable caches are not separated in SLOB, account everything as unreclaimable. SLUB currently doesn't account kmalloc() and kmalloc_node() allocations larger than order-1 page, that are passed directly to the page allocator. As they also don't appear in /proc/slabinfo, it might look like a memory leak. For consistency, account them as well. (SLAB doesn't actually use page allocator directly, so no change there). Ideally SLOB and SLUB would be handled in separate patches, but due to the shared kmalloc_order() function and different kfree() implementations, it's easier to patch both at once to prevent inconsistencies. Link: http://lkml.kernel.org/r/20190826111627.7505-2-vbabka@suse.czSigned-off-by:
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Chris Down authored
This patch is an incremental improvement on the existing memory.{low,min} relative reclaim work to base its scan pressure calculations on how much protection is available compared to the current usage, rather than how much the current usage is over some protection threshold. This change doesn't change the experience for the user in the normal case too much. One benefit is that it replaces the (somewhat arbitrary) 100% cutoff with an indefinite slope, which makes it easier to ballpark a memory.low value. As well as this, the old methodology doesn't quite apply generically to machines with varying amounts of physical memory. Let's say we have a top level cgroup, workload.slice, and another top level cgroup, system-management.slice. We want to roughly give 12G to system-management.slice, so on a 32GB machine we set memory.low to 20GB in workload.slice, and on a 64GB machine we set memory.low to 52GB. However, because these are relative amounts to the total machine size, while the amount of memory we want to generally be willing to yield to system.slice is absolute (12G), we end up putting more pressure on system.slice just because we have a larger machine and a larger workload to fill it, which seems fairly unintuitive. With this new behaviour, we don't end up with this unintended side effect. Previously the way that memory.low protection works is that if you are 50% over a certain baseline, you get 50% of your normal scan pressure. This is certainly better than the previous cliff-edge behaviour, but it can be improved even further by always considering memory under the currently enforced protection threshold to be out of bounds. This means that we can set relatively low memory.low thresholds for variable or bursty workloads while still getting a reasonable level of protection, whereas with the previous version we may still trivially hit the 100% clamp. The previous 100% clamp is also somewhat arbitrary, whereas this one is more concretely based on the currently enforced protection threshold, which is likely easier to reason about. There is also a subtle issue with the way that proportional reclaim worked previously -- it promotes having no memory.low, since it makes pressure higher during low reclaim. This happens because we base our scan pressure modulation on how far memory.current is between memory.min and memory.low, but if memory.low is unset, we only use the overage method. In most cromulent configurations, this then means that we end up with *more* pressure than with no memory.low at all when we're in low reclaim, which is not really very usable or expected. With this patch, memory.low and memory.min affect reclaim pressure in a more understandable and composable way. For example, from a user standpoint, "protected" memory now remains untouchable from a reclaim aggression standpoint, and users can also have more confidence that bursty workloads will still receive some amount of guaranteed protection. Link: http://lkml.kernel.org/r/20190322160307.GA3316@chrisdown.nameSigned-off-by:Chris Down <chris@chrisdown.name> Reviewed-by:
Roman Gushchin <guro@fb.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Dennis Zhou <dennis@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by:
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Chris Down authored
Roman points out that when when we do the low reclaim pass, we scale the reclaim pressure relative to position between 0 and the maximum protection threshold. However, if the maximum protection is based on memory.elow, and memory.emin is above zero, this means we still may get binary behaviour on second-pass low reclaim. This is because we scale starting at 0, not starting at memory.emin, and since we don't scan at all below emin, we end up with cliff behaviour. This should be a fairly uncommon case since usually we don't go into the second pass, but it makes sense to scale our low reclaim pressure starting at emin. You can test this by catting two large sparse files, one in a cgroup with emin set to some moderate size compared to physical RAM, and another cgroup without any emin. In both cgroups, set an elow larger than 50% of physical RAM. The one with emin will have less page scanning, as reclaim pressure is lower. Rebase on top of and apply the same idea as what was applied to handle cgroup_memory=disable properly for the original proportional patch http://lkml.kernel.org/r/20190201045711.GA18302@chrisdown.name ("mm, memcg: Handle cgroup_disable=memory when getting memcg protection"). Link: http://lkml.kernel.org/r/20190201051810.GA18895@chrisdown.nameSigned-off-by:
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Chris Down authored
cgroup v2 introduces two memory protection thresholds: memory.low (best-effort) and memory.min (hard protection). While they generally do what they say on the tin, there is a limitation in their implementation that makes them difficult to use effectively: that cliff behaviour often manifests when they become eligible for reclaim. This patch implements more intuitive and usable behaviour, where we gradually mount more reclaim pressure as cgroups further and further exceed their protection thresholds. This cliff edge behaviour happens because we only choose whether or not to reclaim based on whether the memcg is within its protection limits (see the use of mem_cgroup_protected in shrink_node), but we don't vary our reclaim behaviour based on this information. Imagine the following timeline, with the numbers the lruvec size in this zone: 1. memory.low=1000000, memory.current=999999. 0 pages may be scanned. 2. memory.low=1000000, memory.current=1000000. 0 pages may be scanned. 3. memory.low=1000000, memory.current=1000001. 1000001* pages may be scanned. (?!) * Of course, we won't usually scan all available pages in the zone even without this patch because of scan control priority, over-reclaim protection, etc. However, as shown by the tests at the end, these techniques don't sufficiently throttle such an extreme change in input, so cliff-like behaviour isn't really averted by their existence alone. Here's an example of how this plays out in practice. At Facebook, we are trying to protect various workloads from "system" software, like configuration management tools, metric collectors, etc (see this[0] case study). In order to find a suitable memory.low value, we start by determining the expected memory range within which the workload will be comfortable operating. This isn't an exact science -- memory usage deemed "comfortable" will vary over time due to user behaviour, differences in composition of work, etc, etc. As such we need to ballpark memory.low, but doing this is currently problematic: 1. If we end up setting it too low for the workload, it won't have *any* effect (see discussion above). The group will receive the full weight of reclaim and won't have any priority while competing with the less important system software, as if we had no memory.low configured at all. 2. Because of this behaviour, we end up erring on the side of setting it too high, such that the comfort range is reliably covered. However, protected memory is completely unavailable to the rest of the system, so we might cause undue memory and IO pressure there when we *know* we have some elasticity in the workload. 3. Even if we get the value totally right, smack in the middle of the comfort zone, we get extreme jumps between no pressure and full pressure that cause unpredictable pressure spikes in the workload due to the current binary reclaim behaviour. With this patch, we can set it to our ballpark estimation without too much worry. Any undesirable behaviour, such as too much or too little reclaim pressure on the workload or system will be proportional to how far our estimation is off. This means we can set memory.low much more conservatively and thus waste less resources *without* the risk of the workload falling off a cliff if we overshoot. As a more abstract technical description, this unintuitive behaviour results in having to give high-priority workloads a large protection buffer on top of their expected usage to function reliably, as otherwise we have abrupt periods of dramatically increased memory pressure which hamper performance. Having to set these thresholds so high wastes resources and generally works against the principle of work conservation. In addition, having proportional memory reclaim behaviour has other benefits. Most notably, before this patch it's basically mandatory to set memory.low to a higher than desirable value because otherwise as soon as you exceed memory.low, all protection is lost, and all pages are eligible to scan again. By contrast, having a gradual ramp in reclaim pressure means that you now still get some protection when thresholds are exceeded, which means that one can now be more comfortable setting memory.low to lower values without worrying that all protection will be lost. This is important because workingset size is really hard to know exactly, especially with variable workloads, so at least getting *some* protection if your workingset size grows larger than you expect increases user confidence in setting memory.low without a huge buffer on top being needed. Thanks a lot to Johannes Weiner and Tejun Heo for their advice and assistance in thinking about how to make this work better. In testing these changes, I intended to verify that: 1. Changes in page scanning become gradual and proportional instead of binary. To test this, I experimented stepping further and further down memory.low protection on a workload that floats around 19G workingset when under memory.low protection, watching page scan rates for the workload cgroup: +------------+-----------------+--------------------+--------------+ | memory.low | test (pgscan/s) | control (pgscan/s) | % of control | +------------+-----------------+--------------------+--------------+ | 21G | 0 | 0 | N/A | | 17G | 867 | 3799 | 23% | | 12G | 1203 | 3543 | 34% | | 8G | 2534 | 3979 | 64% | | 4G | 3980 | 4147 | 96% | | 0 | 3799 | 3980 | 95% | +------------+-----------------+--------------------+--------------+ As you can see, the test kernel (with a kernel containing this patch) ramps up page scanning significantly more gradually than the control kernel (without this patch). 2. More gradual ramp up in reclaim aggression doesn't result in premature OOMs. To test this, I wrote a script that slowly increments the number of pages held by stress(1)'s --vm-keep mode until a production system entered severe overall memory contention. This script runs in a highly protected slice taking up the majority of available system memory. Watching vmstat revealed that page scanning continued essentially nominally between test and control, without causing forward reclaim progress to become arrested. [0]: https://facebookmicrosites.github.io/cgroup2/docs/overview.html#case-study-the-fbtax2-project [akpm@linux-foundation.org: reflow block comments to fit in 80 cols] [chris@chrisdown.name: handle cgroup_disable=memory when getting memcg protection] Link: http://lkml.kernel.org/r/20190201045711.GA18302@chrisdown.name Link: http://lkml.kernel.org/r/20190124014455.GA6396@chrisdown.nameSigned-off-by:
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Dan Carpenter authored
The "mode" and "level" variables are enums and in this context GCC will treat them as unsigned ints so the error handling is never triggered. I also removed the bogus initializer because it isn't required any more and it's sort of confusing. [akpm@linux-foundation.org: reduce implicit and explicit typecasting] [akpm@linux-foundation.org: fix return value, add comment, per Matthew] Link: http://lkml.kernel.org/r/20190925110449.GO3264@mwanda Fixes: 3cadfa2b ("mm/vmpressure.c: convert to use match_string() helper") Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by:
David Rientjes <rientjes@google.com> Reviewed-by:
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Qian Cai authored
On architectures like s390, arch_free_page() could mark the page unused (set_page_unused()) and any access later would trigger a kernel panic. Fix it by moving arch_free_page() after all possible accessing calls. Hardware name: IBM 2964 N96 400 (z/VM 6.4.0) Krnl PSW : 0404e00180000000 0000000026c2b96e (__free_pages_ok+0x34e/0x5d8) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000088d43af7 0000000000484000 000000000000007c 000000000000000f 000003d080012100 000003d080013fc0 0000000000000000 0000000000100000 00000000275cca48 0000000000000100 0000000000000008 000003d080010000 00000000000001d0 000003d000000000 0000000026c2b78a 000000002717fdb0 Krnl Code: 0000000026c2b95c: ec1100b30659 risbgn %r1,%r1,0,179,6 0000000026c2b962: e32014000036 pfd 2,1024(%r1) #0000000026c2b968: d7ff10001000 xc 0(256,%r1),0(%r1) >0000000026c2b96e: 41101100 la %r1,256(%r1) 0000000026c2b972: a737fff8 brctg %r3,26c2b962 0000000026c2b976: d7ff10001000 xc 0(256,%r1),0(%r1) 0000000026c2b97c: e31003400004 lg %r1,832 0000000026c2b982: ebff1430016a asi 5168(%r1),-1 Call Trace: __free_pages_ok+0x16a/0x5d8) memblock_free_all+0x206/0x290 mem_init+0x58/0x120 start_kernel+0x2b0/0x570 startup_continue+0x6a/0xc0 INFO: lockdep is turned off. Last Breaking-Event-Address: __free_pages_ok+0x372/0x5d8 Kernel panic - not syncing: Fatal exception: panic_on_oops 00: HCPGIR450W CP entered; disabled wait PSW 00020001 80000000 00000000 26A2379C In the past, only kernel_poison_pages() would trigger this but it needs "page_poison=on" kernel cmdline, and I suspect nobody tested that on s390. Recently, kernel_init_free_pages() (commit 6471384a ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")) was added and could trigger this as well. [akpm@linux-foundation.org: add comment] Link: http://lkml.kernel.org/r/1569613623-16820-1-git-send-email-cai@lca.pw Fixes: 8823b1db ("mm/page_poison.c: enable PAGE_POISONING as a separate option") Fixes: 6471384a ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options") Signed-off-by:Qian Cai <cai@lca.pw> Reviewed-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by:
Christian Borntraeger <borntraeger@de.ibm.com> Acked-by:
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Vitaly Wool authored
There's a really hard to reproduce race in z3fold between z3fold_free() and z3fold_reclaim_page(). z3fold_reclaim_page() can claim the page after z3fold_free() has checked if the page was claimed and z3fold_free() will then schedule this page for compaction which may in turn lead to random page faults (since that page would have been reclaimed by then). Fix that by claiming page in the beginning of z3fold_free() and not forgetting to clear the claim in the end. [vitalywool@gmail.com: v2] Link: http://lkml.kernel.org/r/20190928113456.152742cf@bigdell Link: http://lkml.kernel.org/r/20190926104844.4f0c6efa1366b8f5741eaba9@gmail.comSigned-off-by:
Vitaly Wool <vitalywool@gmail.com> Reported-by:
Markus Linnala <markus.linnala@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Henry Burns <henrywolfeburns@gmail.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Markus Linnala <markus.linnala@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Michal Hocko authored
Partially revert 16db3d3f ("kernel/sysctl.c: threads-max observe limits") because the patch is causing a regression to any workload which needs to override the auto-tuning of the limit provided by kernel. set_max_threads is implementing a boot time guesstimate to provide a sensible limit of the concurrently running threads so that runaways will not deplete all the memory. This is a good thing in general but there are workloads which might need to increase this limit for an application to run (reportedly WebSpher MQ is affected) and that is simply not possible after the mentioned change. It is also very dubious to override an admin decision by an estimation that doesn't have any direct relation to correctness of the kernel operation. Fix this by dropping set_max_threads from sysctl_max_threads so any value is accepted as long as it fits into MAX_THREADS which is important to check because allowing more threads could break internal robust futex restriction. While at it, do not use MIN_THREADS as the lower boundary because it is also only a heuristic for automatic estimation and admin might have a good reason to stop new threads to be created even when below this limit. This became more severe when we switched x86 from 4k to 8k kernel stacks. Starting since 6538b8ea ("x86_64: expand kernel stack to 16K") (3.16) we use THREAD_SIZE_ORDER = 2 and that halved the auto-tuned value. In the particular case 3.12 kernel.threads-max = 515561 4.4 kernel.threads-max = 200000 Neither of the two values is really insane on 32GB machine. I am not sure we want/need to tune the max_thread value further. If anything the tuning should be removed altogether if proven not useful in general. But we definitely need a way to override this auto-tuning. Link: http://lkml.kernel.org/r/20190922065801.GB18814@dhcp22.suse.cz Fixes: 16db3d3f ("kernel/sysctl.c: threads-max observe limits") Signed-off-by:
"Eric W. Biederman" <ebiederm@xmission.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: <stable@vger.kernel.org> Signed-off-by:
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Baoquan He authored
In kdump kernel, memcg usually is disabled with 'cgroup_disable=memory' for saving memory. Now kdump kernel will always panic when dump vmcore to local disk: BUG: kernel NULL pointer dereference, address: 0000000000000ab8 Oops: 0000 [#1] SMP NOPTI CPU: 0 PID: 598 Comm: makedumpfile Not tainted 5.3.0+ #26 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 10/02/2018 RIP: 0010:mem_cgroup_track_foreign_dirty_slowpath+0x38/0x140 Call Trace: __set_page_dirty+0x52/0xc0 iomap_set_page_dirty+0x50/0x90 iomap_write_end+0x6e/0x270 iomap_write_actor+0xce/0x170 iomap_apply+0xba/0x11e iomap_file_buffered_write+0x62/0x90 xfs_file_buffered_aio_write+0xca/0x320 [xfs] new_sync_write+0x12d/0x1d0 vfs_write+0xa5/0x1a0 ksys_write+0x59/0xd0 do_syscall_64+0x59/0x1e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 And this will corrupt the 1st kernel too with 'cgroup_disable=memory'. Via the trace and with debugging, it is pointing to commit 97b27821 ("writeback, memcg: Implement foreign dirty flushing") which introduced this regression. Disabling memcg causes the null pointer dereference at uninitialized data in function mem_cgroup_track_foreign_dirty_slowpath(). Fix it by returning directly if memcg is disabled, but not trying to record the foreign writebacks with dirty pages. Link: http://lkml.kernel.org/r/20190924141928.GD31919@MiWiFi-R3L-srv Fixes: 97b27821 ("writeback, memcg: Implement foreign dirty flushing") Signed-off-by:
Baoquan He <bhe@redhat.com> Acked-by:
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Yi Wang authored
We get two warnings when build kernel W=1: mm/shuffle.c:36:12: warning: no previous prototype for `shuffle_show' [-Wmissing-prototypes] mm/sparse.c:220:6: warning: no previous prototype for `subsection_mask_set' [-Wmissing-prototypes] Make the functions static to fix this. Link: http://lkml.kernel.org/r/1566978161-7293-1-git-send-email-wang.yi59@zte.com.cnSigned-off-by:
Yi Wang <wang.yi59@zte.com.cn> Reviewed-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
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Tejun Heo authored
finish_writeback_work() reads @done->waitq after decrementing @done->cnt. However, once @done->cnt reaches zero, @done may be freed (from stack) at any moment and @done->waitq can contain something unrelated by the time finish_writeback_work() tries to read it. This led to the following crash. "BUG: kernel NULL pointer dereference, address: 0000000000000002" #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP DEBUG_PAGEALLOC CPU: 40 PID: 555153 Comm: kworker/u98:50 Kdump: loaded Not tainted ... Workqueue: writeback wb_workfn (flush-btrfs-1) RIP: 0010:_raw_spin_lock_irqsave+0x10/0x30 Code: 48 89 d8 5b c3 e8 50 db 6b ff eb f4 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 53 9c 5b fa 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 05 48 89 d8 5b c3 89 c6 e8 fe ca 6b ff eb f2 66 90 RSP: 0018:ffffc90049b27d98 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000246 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffff889fff407600 R11: ffff88ba9395d740 R12: 000000000000e300 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88bfdfa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000002 CR3: 0000000002409005 CR4: 00000000001606e0 Call Trace: __wake_up_common_lock+0x63/0xc0 wb_workfn+0xd2/0x3e0 process_one_work+0x1f5/0x3f0 worker_thread+0x2d/0x3d0 kthread+0x111/0x130 ret_from_fork+0x1f/0x30 Fix it by reading and caching @done->waitq before decrementing @done->cnt. Link: http://lkml.kernel.org/r/20190924010631.GH2233839@devbig004.ftw2.facebook.com Fixes: 5b9cce4c ("writeback: Generalize and expose wb_completion") Signed-off-by:
Tejun Heo <tj@kernel.org> Debugged-by:
Chris Mason <clm@fb.com> Reviewed-by:
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