diff options
| -rw-r--r-- | fs/ocfs2/mmap.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c index af2b8fe1f13..4c18f4ad93b 100644 --- a/fs/ocfs2/mmap.c +++ b/fs/ocfs2/mmap.c @@ -74,9 +74,11 @@ static int __ocfs2_page_mkwrite(struct inode *inode, struct buffer_head *di_bh, /* * Another node might have truncated while we were waiting on * cluster locks. + * We don't check size == 0 before the shift. This is borrowed + * from do_generic_file_read. */ - last_index = size >> PAGE_CACHE_SHIFT; - if (page->index > last_index) { + last_index = (size - 1) >> PAGE_CACHE_SHIFT; + if (unlikely(!size || page->index > last_index)) { ret = -EINVAL; goto out; } @@ -107,7 +109,7 @@ static int __ocfs2_page_mkwrite(struct inode *inode, struct buffer_head *di_bh, * because the "write" would invalidate their data. */ if (page->index == last_index) - len = size & ~PAGE_CACHE_MASK; + len = ((size - 1) & ~PAGE_CACHE_MASK) + 1; ret = ocfs2_write_begin_nolock(mapping, pos, len, 0, &locked_page, &fsdata, di_bh, page); |