diff options
| -rw-r--r-- | fs/ocfs2/aops.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 742893ea739..356e976772b 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1100,23 +1100,37 @@ out: */ static int ocfs2_grab_pages_for_write(struct address_space *mapping, struct ocfs2_write_ctxt *wc, - u32 cpos, loff_t user_pos, int new, + u32 cpos, loff_t user_pos, + unsigned user_len, int new, struct page *mmap_page) { int ret = 0, i; - unsigned long start, target_index, index; + unsigned long start, target_index, end_index, index; struct inode *inode = mapping->host; + loff_t last_byte; target_index = user_pos >> PAGE_CACHE_SHIFT; /* * Figure out how many pages we'll be manipulating here. For * non allocating write, we just change the one - * page. Otherwise, we'll need a whole clusters worth. + * page. Otherwise, we'll need a whole clusters worth. If we're + * writing past i_size, we only need enough pages to cover the + * last page of the write. */ if (new) { wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb); start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos); + /* + * We need the index *past* the last page we could possibly + * touch. This is the page past the end of the write or + * i_size, whichever is greater. + */ + last_byte = max(user_pos + user_len, i_size_read(inode)); + BUG_ON(last_byte < 1); + end_index = ((last_byte - 1) >> PAGE_CACHE_SHIFT) + 1; + if ((start + wc->w_num_pages) > end_index) + wc->w_num_pages = end_index - start; } else { wc->w_num_pages = 1; start = target_index; @@ -1773,7 +1787,7 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, * that we can zero and flush if we error after adding the * extent. */ - ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, + ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len, cluster_of_pages, mmap_page); if (ret) { mlog_errno(ret); |