From: Nick Piggin 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 v3: add comments Signed-off-by: Nick Piggin Signed-off-by: Andi Kleen --- include/linux/mm.h | 2 ++ mm/truncate.c | 34 ++++++++++++++++++++++------------ 2 files changed, 24 insertions(+), 12 deletions(-) --- sound-2.6.orig/mm/truncate.c +++ sound-2.6/mm/truncate.c @@ -135,6 +135,26 @@ invalidate_complete_page(struct address_ return ret; } +/* + * Remove one page from its pagecache mapping. The page must be locked. + * This does not truncate the file on disk, it performs the pagecache + * side of the truncate operation. Dirty data will be discarded, and + * concurrent page references are ignored. + * + * Generic mm/fs code cannot call this on filesystem metadata mappings + * because those can assume that a page reference is enough to pin the + * page to its mapping. + */ +void 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); + } + truncate_complete_page(mapping, page); +} + /** * truncate_inode_pages - truncate range of pages specified by start & end byte offsets * @mapping: mapping to truncate @@ -196,12 +216,7 @@ void truncate_inode_pages_range(struct a 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); --- sound-2.6.orig/include/linux/mm.h +++ sound-2.6/include/linux/mm.h @@ -814,6 +814,8 @@ static inline void unmap_shared_mapping_ extern int vmtruncate(struct inode * inode, loff_t offset); extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end); +void truncate_inode_page(struct address_space *mapping, struct page *page); + #ifdef CONFIG_MMU extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, int write_access); -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/