On Mon, Nov 05, 2012 at 10:20:19PM +0100, Lluís Batlle i Rossell wrote:
> Hello,
>
> with the help of Lars on irc, we've tracked down the issue to a broken readdir()
> in ext3 in n32, introduced in the kernel 3.5 by this commit:
> d7dab39b6e16d5eea78ed3c705d2a2d0772b4f06
>
> That renders ext3 quite useless in mips n32.
>
> In a kernel after that commit, the example program in the 'getdents' man page
> returns this:
> [root@fu2:~/readdir]# ./getdents
> --------------- nread=116 ---------------
> i-node# file type d_reclen d_off d_name
> 3694 regular 20 1780583312 prova.c
> 1037850 regular 24 -985956880 getdents.c
> 1037848 directory 16 -1999547753 .
> 1037849 regular 20 222381689 getdents
> 778241 directory 16 -1849228342 ..
> 3647 regular 20 -1 prova
>
>
> I took Lars suggestion of applying the patch I attach (forcing ext3 to think it
> is a 32-bit system), and then all works. init (upstart) doesn't deadlock anymore, readdir() works fine, and the getdents info looks right:
> [root@fu2:~/readdir]# ./getdents
> --------------- nread=116 ---------------
> i-node# file type d_reclen d_off d_name
> 3694 regular 20 334739480 prova.c
> 1037850 regular 24 473707228 getdents.c
> 1037848 directory 16 824759881 .
> 1037849 regular 20 875064456 getdents
> 778241 directory 16 1524836457 ..
> 3647 regular 20 2147483647 prova
>
> How to solve this, I don't know. But it seems that ext3 thinks that mips-n32
> programs can eat some 64-bit words in d_off.
Now I add the patch I mentioned.
Regards,
Lluís.
diff --git a/fs/ext3/dir.c b/fs/ext3/dir.c
index 92490e9..bf63d7b 100644
--- a/fs/ext3/dir.c
+++ b/fs/ext3/dir.c
@@ -228,6 +228,7 @@ out:
static inline int is_32bit_api(void)
{
+ return 1;
#ifdef CONFIG_COMPAT
return is_compat_task();
#else
