2015-02-06 01:19:02

by Xiaoguang Wang

Subject: [PATCH] ext4: fix mmap data corruption in nodelalloc mode when blocksize < pagesize

Since commit 90a8020 and d6320cb, Jan Kara has fixed this issue partially.
This mmap data corruption still exists in nodelalloc mode, fix this.

Signed-off-by: Xiaoguang Wang <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
---
fs/ext4/inode.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9193ea1..0390e41 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1007,6 +1007,7 @@ static int ext4_write_end(struct file *file,
{
handle_t *handle = ext4_journal_current_handle();
struct inode *inode = mapping->host;
+ loff_t old_size = inode->i_size;
int ret = 0, ret2;
int i_size_changed = 0;

@@ -1037,6 +1038,8 @@ static int ext4_write_end(struct file *file,
unlock_page(page);
page_cache_release(page);

+ if (old_size < pos)
+ pagecache_isize_extended(inode, old_size, pos);
/*
* Don't mark the inode dirty under page lock. First, it unnecessarily
* makes the holding time of page lock longer. Second, it forces lock
@@ -1078,6 +1081,7 @@ static int ext4_journalled_write_end(struct file *file,
{
handle_t *handle = ext4_journal_current_handle();
struct inode *inode = mapping->host;
+ loff_t old_size = inode->i_size;
int ret = 0, ret2;
int partial = 0;
unsigned from, to;
@@ -1110,6 +1114,9 @@ static int ext4_journalled_write_end(struct file *file,
unlock_page(page);
page_cache_release(page);

+ if (old_size < pos)
+ pagecache_isize_extended(inode, old_size, pos);
+
if (size_changed) {
ret2 = ext4_mark_inode_dirty(handle, inode);
if (!ret)
--
1.8.3.1

2015-02-13 04:01:39

by Theodore Ts'o

Subject: Re: [PATCH] ext4: fix mmap data corruption in nodelalloc mode when blocksize < pagesize

On Fri, Feb 06, 2015 at 09:13:03AM +0800, Xiaoguang Wang wrote:
> Since commit 90a8020 and d6320cb, Jan Kara has fixed this issue partially.
> This mmap data corruption still exists in nodelalloc mode, fix this.
>
> Signed-off-by: Xiaoguang Wang <[email protected]>
> Reviewed-by: Jan Kara <[email protected]>

Applied, thanks.

- Ted