From 7c116f2b0dbac4a1dd051c7a5e8cef37701cafd4 Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Wed, 16 Dec 2009 12:19:59 +0100 Subject: [PATCH] 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 --- Documentation/vm/hwpoison.txt | 7 +++++ mm/hwpoison-inject.c | 11 ++++++++ mm/internal.h | 3 +++ mm/memory-failure.c | 51 +++++++++++++++++++++++++++++++++++ 4 files changed, 72 insertions(+) diff --git a/Documentation/vm/hwpoison.txt b/Documentation/vm/hwpoison.txt index f047e75acb2..fdf58046432 100644 --- a/Documentation/vm/hwpoison.txt +++ b/Documentation/vm/hwpoison.txt @@ -115,6 +115,13 @@ memory failures. Note these injection interfaces are not stable and might change between kernel versions +corrupt-filter-dev-major +corrupt-filter-dev-minor + +Only handle memory failures to pages associated with the file system defined +by block device major/minor. -1U is the wildcard value. +This should be only used for testing with artificial injection. + Architecture specific MCE injector x86 has mce-inject, mce-test diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c index 6e35e563bf5..ac692a9b766 100644 --- a/mm/hwpoison-inject.c +++ b/mm/hwpoison-inject.c @@ -3,6 +3,7 @@ #include #include #include +#include "internal.h" static struct dentry *hwpoison_dir; @@ -54,6 +55,16 @@ static int pfn_inject_init(void) if (!dentry) goto fail; + dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600, + hwpoison_dir, &hwpoison_filter_dev_major); + if (!dentry) + goto fail; + + dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600, + hwpoison_dir, &hwpoison_filter_dev_minor); + if (!dentry) + goto fail; + return 0; fail: pfn_inject_exit(); diff --git a/mm/internal.h b/mm/internal.h index 49b2ff776b7..814da335f05 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -250,3 +250,6 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, #define ZONE_RECLAIM_SOME 0 #define ZONE_RECLAIM_SUCCESS 1 #endif + +extern u32 hwpoison_filter_dev_major; +extern u32 hwpoison_filter_dev_minor; diff --git a/mm/memory-failure.c b/mm/memory-failure.c index edeaf2319e7..82ac73436d0 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); -- 2.39.3