The patch titled
Remove semi-softlockup from invalidate_mapping_pages
has been added to the -mm tree. Its filename is
remove-softlockup-from-invalidate_mapping_pages.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: NeilBrown <neilb@xxxxxxx>
If invalidate_mapping_pages is called to invalidate a very large mapping
(e.g. a very large block device) and if the only active page in that
device is near the end (or at least, at a very large index), such as, say,
the superblock of an md array, and if that page happens to be locked when
invalidate_mapping_pages is called, then
pagevec_lookup will return this page and
as it is locked, 'next' will be incremented and pagevec_lookup
will be called again. and again. and again.
while we count from 0 upto a very large number.
We should really always set 'next' to 'page->index+1' before going around
the loop again, not just if the page isn't locked.
Cc: "Steinar H. Gunderson" <sgunderson@xxxxxxxxxxx>
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/truncate.c | 22 ++++++++++++++++------
1 files changed, 16 insertions(+), 6 deletions(-)
diff -puN mm/truncate.c~remove-softlockup-from-invalidate_mapping_pages mm/truncate.c
--- devel/mm/truncate.c~remove-softlockup-from-invalidate_mapping_pages 2006-04-20 00:20:49.000000000 -0700
+++ devel-akpm/mm/truncate.c 2006-04-20 00:28:18.000000000 -0700
@@ -230,14 +230,24 @@ unsigned long invalidate_mapping_pages(s
pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
for (i = 0; i < pagevec_count(&pvec); i++) {
struct page *page = pvec.pages[i];
+ pgoff_t index;
+ int locked;
- if (TestSetPageLocked(page)) {
- next++;
- continue;
- }
- if (page->index > next)
- next = page->index;
+ locked = TestSetPageLocked(page);
+
+ /*
+ * We really shouldn't be looking at the ->index of an
+ * unlocked page. But we're not allowed to lock these
+ * pages. So we rely upon nobody altering the ->index
+ * of this (pinned-by-us) page.
+ */
+ index = page->index;
+ if (index > next)
+ next = index;
next++;
+ if (!locked)
+ continue;
+
if (PageDirty(page) || PageWriteback(page))
goto unlock;
if (page_mapped(page))
_
Patches currently in -mm which might be from neilb@xxxxxxx are
md-locking-fix.patch
remove-softlockup-from-invalidate_mapping_pages.patch
fix-dcache-race-during-umount.patch
fix-dcache-race-during-umount-fix.patch
prune_one_dentry-tweaks.patch
make-address_space_operations-invalidatepage-return-void-reiser4.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
-
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