Bug#334961: kernel-image: kernel BUG at return value of cciss_ioctl()

[MAENO Masaki <maeno.masaki@nttcom.co.jp>]

On Fri, 21 Oct 2005 16:06:23 +0900
"Simon Horman [Horms]" <horms@verge.net.au> wrote:
> 
> On Fri, Oct 21, 2005 at 03:39:38PM +0900, MAENO Masaki wrote:
> > Package: kernel-image
> > Version: 2.6.8-2
> > Severity: normal
> > 
> > "fsync_bdev()" cannot be executed in issuing "ioctl(BLKFLSBUF)" to disk drive using cciss driver.
> >   (When return value of "ioctl(BLKFLSBUF)" is only "-EINVAL", "fsync_bdev()" is executed.
> >    But "fsync_bdev()" isn't executed bacause its value is "-EBADRQC".)
> > 
> > I suggest that you correct source as follows:
> >   drivers/block/cciss.c:1093
> >     - return -EBADRQC;
> >     + return -EINVAL;
> 
> I took a look at the upstream tree, and it seems that the return 
> value is now -ENOTTY. Do you think that return value is correct?

I know that the thing to return -EINVAL is an old specification.
I think the preferable value is -ENOTTY, but influence on other
parts is large.
I confirmed that it works good by fix above-mentioned in my
environment, tentatively...


> Also, as 2.6.8 is now in the deep-freeze as the kernel for sarge,
> can you comment on if this patch is critical enough to warrant inclusion
> in a sarge update?

You are correct. So, I suggest that it isn't influence other parts
easily to correct as follows(return errno is no change bacause of
user application):
  drivers/block/ioctl.c:197
    -if (ret != -EINVAL)
    +if (ret != -EINVAL && ret != -EBADRQC)


I tried to verify whether this patch was safe about the part where -EBADRQC
is used by ioctl(BLKFLSBUF).

======
* filename and linenum using BLKFLSBUF searched by grep:
drivers/mtd/mtd_blkdevs.c, line 206 -- case BLKFLSBUF:
  - no return -EBADRQC.
drivers/block/ioctl.c, line 192 -- case BLKFLSBUF:
  - patch part.
drivers/block/nbd.c, line 111 -- case BLKFLSBUF: return "flush-buffer-cache";
  - no return -EBADRQC.
drivers/block/rd.c, line 306 -- if (cmd != BLKFLSBUF)
  - no return -EBADRQC (-EBUSY only).
include/linux/fs.h, line 190 -- #define BLKFLSBUF _IO(0x12,97)
  - no problem.
include/linux/compat_ioctl.h, line 100 -- COMPATIBLE_IOCTL(BLKFLSBUF)
  - no problem.
init/do_mounts_initrd.c, line 96 -- error = sys_ioctl(fd, BLKFLSBUF, 0);
  - no problem.

== Reference
* filename and linenum using EBADRQC searched by grep:
drivers/block/cciss.c, line 1093 -- return -EBADRQC;
drivers/scsi/ch.c, line 174 -- .errno = EBADRQC,
drivers/message/fusion/mptctl.c, line 903 -- return -EBADRQC;
fs/afs/vlclient.c, line 74 -- case AFSVL_BADVOLOPER: err = -EBADRQC; break;
fs/afs/vlocation.c, line 812 -- case -EBADRQC:
fs/cifs/netmisc.c, line 94 -- {ERRsmbcmd, -EBADRQC},
fs/ncpfs/ioctl.c, line 116 -- return -EBADRQC;
fs/ncpfs/ioctl.c, line 132 -- return -EBADRQC;
net/bluetooth/lib.c, line 95 -- return EBADRQC;
======

I think OK, please point it out to me if there is a problem.

Thanks.


-- 
MAENO, Masaki <maeno.masaki@nttcom.co.jp>