The patch titled
mm-speculative-page-references-hugh-fix3
has been added to the -mm tree. Its filename is
mm-speculative-page-references-hugh-fix3.patch
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------------------------------------------------------
Subject: mm-speculative-page-references-hugh-fix3
From: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Fix the VM_BUG_ON assertion check to actually do what I want, noted by
Christoph.
Also, fix an error-path-leak type issue with frozen refcount not being
unfrozen. Found by review. In practice, this check is very rare to
hit because a page dirtier is likely to hold the refcount elevated for
much longer than it takes to check and non-racy-recheck. So it doesn't
pose a big problem for users of -mm, but of course needs fixing.
Cc: Christoph Lameter <clameter@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pagemap.h | 2 +-
mm/vmscan.c | 4 +++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff -puN include/linux/pagemap.h~mm-speculative-page-references-hugh-fix3 include/linux/pagemap.h
--- a/include/linux/pagemap.h~mm-speculative-page-references-hugh-fix3
+++ a/include/linux/pagemap.h
@@ -137,7 +137,7 @@ static inline int page_cache_get_specula
return 0;
}
#endif
- VM_BUG_ON(PageCompound(page) && (struct page *)page_private(page) != page);
+ VM_BUG_ON(PageTail(page));
return 1;
}
diff -puN mm/vmscan.c~mm-speculative-page-references-hugh-fix3 mm/vmscan.c
--- a/mm/vmscan.c~mm-speculative-page-references-hugh-fix3
+++ a/mm/vmscan.c
@@ -428,8 +428,10 @@ static int __remove_mapping(struct addre
if (!page_freeze_refs(page, 2))
goto cannot_free;
/* note: atomic_cmpxchg in page_freeze_refs provides the smp_rmb */
- if (unlikely(PageDirty(page)))
+ if (unlikely(PageDirty(page))) {
+ page_unfreeze_refs(page, 2);
goto cannot_free;
+ }
if (PageSwapCache(page)) {
swp_entry_t swap = { .val = page_private(page) };
_
Patches currently in -mm which might be from nickpiggin@xxxxxxxxxxxx are
git-unionfs.patch
page-flags-record-page-flag-overlays-explicitly.patch
page-flags-record-page-flag-overlays-explicitly-xen.patch
slub-record-page-flag-overlays-explicitly.patch
slob-record-page-flag-overlays-explicitly.patch
vfs-pagecache-usage-optimization-onpagesize=blocksize-environment.patch
generic_file_aio_read-cleanups.patch
cputopology-always-define-cpu-topology-information.patch
cputopology-always-define-cpu-topology-information-cleanup.patch
mm-speculative-page-references-fix-fix.patch
mm-speculative-page-references-hugh-fix3.patch
reiser4-tree_lock-fixes.patch
reiser4-tree_lock-fixes-fix.patch
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