I got it!
Thanks,
Yongqiang.
On Fri, Sep 28, 2012 at 11:08 AM, Yongqiang Yang <xiaoqiangnk@xxxxxxxxx> wrote:
> Hi Curt,
>
> In journal mode, IMHO the case you described also happens. Could you
> shed light on journal mode case?
>
> Thanks,
> Yongqiang.
>
> On Tue, Jun 1, 2010 at 8:03 PM, Theodore Ts'o <tytso@xxxxxxx> wrote:
>> From: Curt Wohlgemuth <curtw@xxxxxxxxxx>
>>
>> commit 8b472d739b2ddd8ab7fb278874f696cd95b25a5e upstream (as of v2.6.34-rc6)
>>
>> In the no-journal case, ext4_write_inode() will fetch the bh and call
>> sync_dirty_buffer() on it. However, if the bh has already been
>> written and the bh reclaimed for some other purpose, AND if the inode
>> is the only one in the inode table block in use, then
>> ext4_get_inode_loc() will not read the inode table block from disk,
>> but as an optimization, fill the block with zero's assuming that its
>> caller will copy in the on-disk version of the inode. This is not
>> done by ext4_write_inode(), so the contents of the inode can simply
>> get lost. The fix is to use __ext4_get_inode_loc() with in_mem set to
>> 0, instead of ext4_get_inode_loc(). Long term the API needs to be
>> fixed so it's obvious why latter is not safe.
>>
>> Addresses-Google-Bug: #2526446
>>
>> Signed-off-by: Curt Wohlgemuth <curtw@xxxxxxxxxx>
>> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
>> ---
>> fs/ext4/inode.c | 2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
>> index ff04c74..28152f8 100644
>> --- a/fs/ext4/inode.c
>> +++ b/fs/ext4/inode.c
>> @@ -5204,7 +5204,7 @@ int ext4_write_inode(struct inode *inode, int wait)
>> } else {
>> struct ext4_iloc iloc;
>>
>> - err = ext4_get_inode_loc(inode, &iloc);
>> + err = __ext4_get_inode_loc(inode, &iloc, 0);
>> if (err)
>> return err;
>> if (wait)
>> --
>> 1.6.6.1.1.g974db.dirty
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>
> --
> Best Wishes
> Yongqiang Yang
--
Best Wishes
Yongqiang Yang
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
