Commit e58ff155 authored Jul 24, 2013 by Kent Overstreet

bcache: Fix bch_ptr_bad()



Previously, bch_ptr_bad() could return false when there was a pointer to
a nonexistant device... it only filtered out keys with PTR_CHECK_DEV
pointers.

This behaviour was intended for multiple cache device support; for that,
just because the device for one of the pointers has gone away doesn't
mean we want to filter out the rest of the pointers.

But we don't yet explicitly filter/check individual pointers, so without
that this behaviour was wrong - a corrupt bkey with a bad device pointer
could cause us to deref a bad pointer. Doh.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

parent 81ab4190

drivers/md/bcache/bset.c

+33 −34

Original line number	Diff line number	Diff line
		@@ -116,11 +116,10 @@ bool bch_ptr_bad(struct btree b, const struct bkey k)
		bch_ptr_invalid(b, k))
		return true;

		if (KEY_PTRS(k) && PTR_DEV(k, 0) == PTR_CHECK_DEV)
		for (i = 0; i < KEY_PTRS(k); i++) {
		if (!ptr_available(b->c, k, i))
		return true;

		for (i = 0; i < KEY_PTRS(k); i++)
		if (ptr_available(b->c, k, i)) {
		g = PTR_BUCKET(b->c, k, i);
		stale = ptr_stale(b->c, k, i);

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