diff options
| -rw-r--r-- | include/linux/mm.h | 2 | ||||
| -rw-r--r-- | mm/truncate.c | 26 |
2 files changed, 22 insertions, 6 deletions
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; |