From 750b4987b0cd4d408e54cb83a80a067cbe690feb Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Wed, 16 Sep 2009 11:50:12 +0200 Subject: HWPOISON: Refactor truncate to allow direct truncating of page v2 Extract out truncate_inode_page() out of the truncate path so that it can be used by memory-failure.c [AK: description, headers, fix typos] v2: Some white space changes from Fengguang Wu Signed-off-by: Andi Kleen --- mm/truncate.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) (limited to 'mm/truncate.c') diff --git a/mm/truncate.c b/mm/truncate.c index ccc3ecf7cb98..2519a7c92873 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -93,11 +93,11 @@ EXPORT_SYMBOL(cancel_dirty_page); * its lock, b) when a concurrent invalidate_mapping_pages got there first and * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space. */ -static void +static int truncate_complete_page(struct address_space *mapping, struct page *page) { if (page->mapping != mapping) - return; + return -EIO; if (page_has_private(page)) do_invalidatepage(page, 0); @@ -108,6 +108,7 @@ truncate_complete_page(struct address_space *mapping, struct page *page) remove_from_page_cache(page); ClearPageMappedToDisk(page); page_cache_release(page); /* pagecache ref */ + return 0; } /* @@ -135,6 +136,16 @@ invalidate_complete_page(struct address_space *mapping, struct page *page) return ret; } +int truncate_inode_page(struct address_space *mapping, struct page *page) +{ + if (page_mapped(page)) { + unmap_mapping_range(mapping, + (loff_t)page->index << PAGE_CACHE_SHIFT, + PAGE_CACHE_SIZE, 0); + } + return truncate_complete_page(mapping, page); +} + /** * truncate_inode_pages - truncate range of pages specified by start & end byte offsets * @mapping: mapping to truncate @@ -196,12 +207,7 @@ void truncate_inode_pages_range(struct address_space *mapping, unlock_page(page); continue; } - if (page_mapped(page)) { - unmap_mapping_range(mapping, - (loff_t)page_index<index<index > next) next = page->index; next++; - truncate_complete_page(mapping, page); unlock_page(page); } pagevec_release(&pvec); -- cgit v1.2.3 From 83f786680aec8d030184f7ced1a0a3dd8ac81764 Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Wed, 16 Sep 2009 11:50:13 +0200 Subject: HWPOISON: Add invalidate_inode_page Add a simple way to invalidate a single page This is just a refactoring of the truncate.c code. Originally from Fengguang, modified by Andi Kleen. Signed-off-by: Andi Kleen --- include/linux/mm.h | 2 ++ mm/truncate.c | 26 ++++++++++++++++++++------ 2 files changed, 22 insertions(+), 6 deletions(-) (limited to 'mm/truncate.c') diff --git a/include/linux/mm.h b/include/linux/mm.h index 8cbc0aafd5bd..b05bbde0296d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -796,6 +796,8 @@ extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end); int truncate_inode_page(struct address_space *mapping, struct page *page); +int invalidate_inode_page(struct page *page); + #ifdef CONFIG_MMU extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, unsigned int flags); diff --git a/mm/truncate.c b/mm/truncate.c index 2519a7c92873..ea132f7ea2d2 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -146,6 +146,24 @@ int truncate_inode_page(struct address_space *mapping, struct page *page) return truncate_complete_page(mapping, page); } +/* + * Safely invalidate one page from its pagecache mapping. + * It only drops clean, unused pages. The page must be locked. + * + * Returns 1 if the page is successfully invalidated, otherwise 0. + */ +int invalidate_inode_page(struct page *page) +{ + struct address_space *mapping = page_mapping(page); + if (!mapping) + return 0; + if (PageDirty(page) || PageWriteback(page)) + return 0; + if (page_mapped(page)) + return 0; + return invalidate_complete_page(mapping, page); +} + /** * truncate_inode_pages - truncate range of pages specified by start & end byte offsets * @mapping: mapping to truncate @@ -312,12 +330,8 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping, if (lock_failed) continue; - if (PageDirty(page) || PageWriteback(page)) - goto unlock; - if (page_mapped(page)) - goto unlock; - ret += invalidate_complete_page(mapping, page); -unlock: + ret += invalidate_inode_page(page); + unlock_page(page); if (next > end) break; -- cgit v1.2.3 From 257187362123f15d9d1e09918cf87cebbea4e786 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 16 Sep 2009 11:50:13 +0200 Subject: HWPOISON: Define a new error_remove_page address space op for async truncation Truncating metadata pages is not safe right now before we haven't audited all file systems. To enable truncation only for data address space define a new address_space callback error_remove_page. This is used for memory_failure.c memory error handling. This can be then set to truncate_inode_page() This patch just defines the new operation and adds documentation. Callers and users come in followon patches. Signed-off-by: Andi Kleen --- Documentation/filesystems/vfs.txt | 7 +++++++ include/linux/fs.h | 1 + include/linux/mm.h | 1 + mm/truncate.c | 17 +++++++++++++++++ 4 files changed, 26 insertions(+) (limited to 'mm/truncate.c') diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index f49eecf2e573..623f094c9d8d 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -536,6 +536,7 @@ struct address_space_operations { /* migrate the contents of a page to the specified target */ int (*migratepage) (struct page *, struct page *); int (*launder_page) (struct page *); + int (*error_remove_page) (struct mapping *mapping, struct page *page); }; writepage: called by the VM to write a dirty page to backing store. @@ -694,6 +695,12 @@ struct address_space_operations { prevent redirtying the page, it is kept locked during the whole operation. + error_remove_page: normally set to generic_error_remove_page if truncation + is ok for this address space. Used for memory failure handling. + Setting this implies you deal with pages going away under you, + unless you have them locked or reference counts increased. + + The File Object =============== diff --git a/include/linux/fs.h b/include/linux/fs.h index b21cf6b9c80b..4f47afd37647 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -595,6 +595,7 @@ struct address_space_operations { int (*launder_page) (struct page *); int (*is_partially_uptodate) (struct page *, read_descriptor_t *, unsigned long); + int (*error_remove_page)(struct address_space *, struct page *); }; /* diff --git a/include/linux/mm.h b/include/linux/mm.h index b05bbde0296d..a16018f7d61c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -795,6 +795,7 @@ extern int vmtruncate(struct inode * inode, loff_t offset); extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end); int truncate_inode_page(struct address_space *mapping, struct page *page); +int generic_error_remove_page(struct address_space *mapping, struct page *page); int invalidate_inode_page(struct page *page); diff --git a/mm/truncate.c b/mm/truncate.c index ea132f7ea2d2..a17b3977cfdf 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -146,6 +146,23 @@ int truncate_inode_page(struct address_space *mapping, struct page *page) return truncate_complete_page(mapping, page); } +/* + * Used to get rid of pages on hardware memory corruption. + */ +int generic_error_remove_page(struct address_space *mapping, struct page *page) +{ + if (!mapping) + return -EINVAL; + /* + * Only punch for normal data pages for now. + * Handling other types like directories would need more auditing. + */ + if (!S_ISREG(mapping->host->i_mode)) + return -EIO; + return truncate_inode_page(mapping, page); +} +EXPORT_SYMBOL(generic_error_remove_page); + /* * Safely invalidate one page from its pagecache mapping. * It only drops clean, unused pages. The page must be locked. -- cgit v1.2.3