Re: Spinlock Related Debug Messages in Block Driver

["Srinivas Ganji" <srinivasganji.linux@gmail.com>]

On 7/11/06, Jens Axboe <axboe@suse.de> wrote:
> On Tue, Jul 11 2006, Srinivas Ganji wrote:
> > Dear All,
> >
> > I implemented the sample block driver for the removable devices and
> > the code contains no statements related to the spin lock except a lock
> > to the blk_init_queue API as shown below.
> >
> > spinlock_t qlock;
> > gDisk->blkqueue = blk_init_queue(do_my_request, &gDisk->qlock);
> >
> > The kernel version is 2.6.10.
> >
> > Everything works fine but when I try to copy a file of huge size
> > (about 100MB), the following debug messages are getting displayed on
> > the console:
> >
> > Fc3: drivers/block/ll_rw_blk.c: 2351: spin_lock already locked by the
> > drivers.
> > Fc3: drivers/block/ll_rw_blk.c: 2468: spin_unlock not locked by the drivers.
> >
> > In spite of these debug messages; the file is getting copied successfully.
> > I studied the Block driver 16th chapter in LDD third edition.
> >
> > Can any one provide a pointer to these debug messages. Do I need to
> > implement any patches for the kernel.
>
> You need to initialize the lock passed to blk_init_queue() first. See eg
> spin_lock_init(), or one of the static initializers
> (SPIN_LOCK_UNLOCKED).
>
> --
> Jens Axboe

Dear Jen,

Thanks for  your reply.
I used the spin_lock_init API before blk_init_queue API. Even though I
got the error.

Is there any other reason for gertting the error messages?

Thanks and Regards,
Srinivas G