[Ocfs2-devel] [PATCH] ocfs2: make __ocfs2_page_mkwrite handle file end properly.
Tao Ma
tao.ma at oracle.com
Fri Jul 16 07:21:00 PDT 2010
__ocfs2_page_mkwrite now is broken in handling file end.
1. the last page should be the page contains i_size - 1.
2. the len in the last page is also calculated wrong.
So change them accordingly.
Signed-off-by: Tao Ma <tao.ma at oracle.com>
---
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 af2b8fe..4c18f4a 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);
--
1.7.1.GIT
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