From 7c116f2b0dbac4a1dd051c7a5e8cef37701cafd4 Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Wed, 16 Dec 2009 12:19:59 +0100 Subject: HWPOISON: add fs/device filters Filesystem data/metadata present the most tricky-to-isolate pages. It requires careful code review and stress testing to get them right. The fs/device filter helps to target the stress tests to some specific filesystem pages. The filter condition is block device's major/minor numbers: - corrupt-filter-dev-major - corrupt-filter-dev-minor When specified (non -1), only page cache pages that belong to that device will be poisoned. The filters are checked reliably on the locked and refcounted page. Haicheng: clear PG_hwpoison and drop bad page count if filter not OK AK: Add documentation CC: Haicheng Li CC: Nick Piggin Signed-off-by: Wu Fengguang Signed-off-by: Andi Kleen --- mm/memory-failure.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) (limited to 'mm/memory-failure.c') diff --git a/mm/memory-failure.c b/mm/memory-failure.c index edeaf2319e74..82ac73436d0e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -48,6 +48,50 @@ int sysctl_memory_failure_recovery __read_mostly = 1; atomic_long_t mce_bad_pages __read_mostly = ATOMIC_LONG_INIT(0); +u32 hwpoison_filter_dev_major = ~0U; +u32 hwpoison_filter_dev_minor = ~0U; +EXPORT_SYMBOL_GPL(hwpoison_filter_dev_major); +EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor); + +static int hwpoison_filter_dev(struct page *p) +{ + struct address_space *mapping; + dev_t dev; + + if (hwpoison_filter_dev_major == ~0U && + hwpoison_filter_dev_minor == ~0U) + return 0; + + /* + * page_mapping() does not accept slab page + */ + if (PageSlab(p)) + return -EINVAL; + + mapping = page_mapping(p); + if (mapping == NULL || mapping->host == NULL) + return -EINVAL; + + dev = mapping->host->i_sb->s_dev; + if (hwpoison_filter_dev_major != ~0U && + hwpoison_filter_dev_major != MAJOR(dev)) + return -EINVAL; + if (hwpoison_filter_dev_minor != ~0U && + hwpoison_filter_dev_minor != MINOR(dev)) + return -EINVAL; + + return 0; +} + +int hwpoison_filter(struct page *p) +{ + if (hwpoison_filter_dev(p)) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(hwpoison_filter); + /* * Send all the processes who have the page mapped an ``action optional'' * signal. @@ -843,6 +887,13 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) res = 0; goto out; } + if (hwpoison_filter(p)) { + if (TestClearPageHWPoison(p)) + atomic_long_dec(&mce_bad_pages); + unlock_page(p); + put_page(p); + return 0; + } wait_on_page_writeback(p); -- cgit v1.2.3-55-g7522