Hugh Dickins eee0f252c6 mm: fix page_lock_anon_vma leaving mutex locked ...

On one machine I've been getting hangs, a page fault's anon_vma_prepare()
waiting in anon_vma_lock(), other processes waiting for that page's lock.

This is a replay of last year's f18194275c39 "mm: fix hang on
anon_vma->root->lock".

The new page_lock_anon_vma() places too much faith in its refcount: when
it has acquired the mutex_trylock(), it's possible that a racing task in
anon_vma_alloc() has just reallocated the struct anon_vma, set refcount
to 1, and is about to reset its anon_vma->root.

Fix this by saving anon_vma->root, and relying on the usual page_mapped()
check instead of a refcount check: if page is still mapped, the anon_vma
is still ours; if page is not still mapped, we're no longer interested.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2011-05-28 16:55:32 -07:00

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backing-dev.c

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bootmem.c

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bounce.c

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cleancache.c

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compaction.c

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debug-pagealloc.c

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dmapool.c

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fadvise.c

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failslab.c

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filemap_xip.c

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filemap.c

Cache xattr security drop check for write v2

2011-05-28 12:02:09 -04:00

fremap.c

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highmem.c

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huge_memory.c

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hugetlb.c

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hwpoison-inject.c

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init-mm.c

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internal.h

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Kconfig

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Kconfig.debug

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kmemcheck.c

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kmemleak-test.c

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kmemleak.c

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ksm.c

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maccess.c

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madvise.c

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Makefile

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memblock.c

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memcontrol.c

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memory_hotplug.c

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memory-failure.c

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memory.c

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mempolicy.c

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mempool.c

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migrate.c

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mincore.c

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mlock.c

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mm_init.c

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mmap.c

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mmu_context.c

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mmu_notifier.c

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mmzone.c

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mprotect.c

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mremap.c

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msync.c

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nobootmem.c

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nommu.c

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oom_kill.c

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page_alloc.c

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page_cgroup.c

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page_io.c

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page_isolation.c

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page-writeback.c

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pagewalk.c

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percpu-km.c

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percpu-vm.c

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percpu.c

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pgtable-generic.c

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prio_tree.c

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quicklist.c

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readahead.c

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rmap.c

mm: fix page_lock_anon_vma leaving mutex locked

2011-05-28 16:55:32 -07:00

shmem.c

tmpfs: fix race between truncate and writepage

2011-05-28 16:09:26 -07:00

slab.c

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slob.c

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slub.c

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sparse-vmemmap.c

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sparse.c

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swap_state.c

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swap.c

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swapfile.c

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thrash.c

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truncate.c

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util.c

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vmalloc.c

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vmscan.c

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vmstat.c

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