From 65c4db8c8282cd239f0ba3226cfe59cc9768193c Mon Sep 17 00:00:00 2001 From: Ryan Ding Date: Fri, 25 Mar 2016 14:20:58 -0700 Subject: [PATCH] ocfs2: test target page before change it To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock. Direct io data will not appear in buffer. The w_target_page member will not be filled by direct io. So avoid to use it when it's NULL. Unlinke buffer io and mmap, direct io will call write_begin with more than 1 page a time. So the target_index is not sufficient to describe the actual data. change it to a range start at target_index, end in end_index. Signed-off-by: Ryan Ding Reviewed-by: Junxiao Bi Cc: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/aops.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 516ea896f13c..100f7a8a0de1 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1406,12 +1406,13 @@ static void ocfs2_write_failure(struct inode *inode, to = user_pos + user_len; struct page *tmppage; - ocfs2_zero_new_buffers(wc->w_target_page, from, to); + if (wc->w_target_page) + ocfs2_zero_new_buffers(wc->w_target_page, from, to); for(i = 0; i < wc->w_num_pages; i++) { tmppage = wc->w_pages[i]; - if (page_has_buffers(tmppage)) { + if (tmppage && page_has_buffers(tmppage)) { if (ocfs2_should_order_data(inode)) ocfs2_jbd2_file_inode(wc->w_handle, inode); @@ -1541,11 +1542,13 @@ static int ocfs2_grab_pages_for_write(struct address_space *mapping, wc->w_num_pages = 1; start = target_index; } + end_index = (user_pos + user_len - 1) >> PAGE_CACHE_SHIFT; for(i = 0; i < wc->w_num_pages; i++) { index = start + i; - if (index == target_index && mmap_page) { + if (index >= target_index && index <= end_index && + wc->w_type == OCFS2_WRITE_MMAP) { /* * ocfs2_pagemkwrite() is a little different * and wants us to directly use the page @@ -1564,6 +1567,11 @@ static int ocfs2_grab_pages_for_write(struct address_space *mapping, page_cache_get(mmap_page); wc->w_pages[i] = mmap_page; wc->w_target_locked = true; + } else if (index >= target_index && index <= end_index && + wc->w_type == OCFS2_WRITE_DIRECT) { + /* Direct write has no mapping page. */ + wc->w_pages[i] = NULL; + continue; } else { wc->w_pages[i] = find_or_create_page(mapping, index, GFP_NOFS); @@ -1665,6 +1673,12 @@ static int ocfs2_write_cluster(struct address_space *mapping, for(i = 0; i < wc->w_num_pages; i++) { int tmpret; + /* This is the direct io target page. */ + if (wc->w_pages[i] == NULL) { + p_blkno++; + continue; + } + tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc, wc->w_pages[i], cpos, user_pos, user_len, @@ -2266,7 +2280,8 @@ try_again: ocfs2_free_alloc_context(meta_ac); success: - *pagep = wc->w_target_page; + if (pagep) + *pagep = wc->w_target_page; *fsdata = wc; return 0; out_quota: @@ -2400,18 +2415,23 @@ int ocfs2_write_end_nolock(struct address_space *mapping, goto out_write_size; } - if (unlikely(copied < len)) { + if (unlikely(copied < len) && wc->w_target_page) { if (!PageUptodate(wc->w_target_page)) copied = 0; ocfs2_zero_new_buffers(wc->w_target_page, start+copied, start+len); } - flush_dcache_page(wc->w_target_page); + if (wc->w_target_page) + flush_dcache_page(wc->w_target_page); for(i = 0; i < wc->w_num_pages; i++) { tmppage = wc->w_pages[i]; + /* This is the direct io target page. */ + if (tmppage == NULL) + continue; + if (tmppage == wc->w_target_page) { from = wc->w_target_from; to = wc->w_target_to; -- 2.20.1