From d47992f86b307985b3215bcf141d56d1849d71df Mon Sep 17 00:00:00 2001 From: Lukas Czerner Date: Tue, 21 May 2013 23:17:23 -0400 Subject: mm: change invalidatepage prototype to accept length Currently there is no way to truncate partial page where the end truncate point is not at the end of the page. This is because it was not needed and the functionality was enough for file system truncate operation to work properly. However more file systems now support punch hole feature and it can benefit from mm supporting truncating page just up to the certain point. Specifically, with this functionality truncate_inode_pages_range() can be changed so it supports truncating partial page at the end of the range (currently it will BUG_ON() if 'end' is not at the end of the page). This commit changes the invalidatepage() address space operation prototype to accept range to be invalidated and update all the instances for it. We also change the block_invalidatepage() in the same way and actually make a use of the new length argument implementing range invalidation. Actual file system implementations will follow except the file systems where the changes are really simple and should not change the behaviour in any way .Implementation for truncate_page_range() which will be able to accept page unaligned ranges will follow as well. Signed-off-by: Lukas Czerner Cc: Andrew Morton Cc: Hugh Dickins --- fs/afs/file.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'fs/afs') diff --git a/fs/afs/file.c b/fs/afs/file.c index 8f6e9234d56..66d50fe2ee4 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -19,7 +19,8 @@ #include "internal.h" static int afs_readpage(struct file *file, struct page *page); -static void afs_invalidatepage(struct page *page, unsigned long offset); +static void afs_invalidatepage(struct page *page, unsigned int offset, + unsigned int length); static int afs_releasepage(struct page *page, gfp_t gfp_flags); static int afs_launder_page(struct page *page); @@ -310,16 +311,17 @@ static int afs_launder_page(struct page *page) * - release a page and clean up its private data if offset is 0 (indicating * the entire page) */ -static void afs_invalidatepage(struct page *page, unsigned long offset) +static void afs_invalidatepage(struct page *page, unsigned int offset, + unsigned int length) { struct afs_writeback *wb = (struct afs_writeback *) page_private(page); - _enter("{%lu},%lu", page->index, offset); + _enter("{%lu},%u,%u", page->index, offset, length); BUG_ON(!PageLocked(page)); /* we clean up only if the entire page is being invalidated */ - if (offset == 0) { + if (offset == 0 && length == PAGE_CACHE_SIZE) { #ifdef CONFIG_AFS_FSCACHE if (PageFsCache(page)) { struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); -- cgit v1.2.3-70-g09d2