On Thu, May 12, 2016 at 6:13 PM, Markus Pargmann <[email protected]> wrote: > Hi, > > On Thursday 12 May 2016 16:42:31 Pranay Srivastava wrote: >> Hi Markus, >> >> >> On Thu, May 12, 2016 at 3:13 PM, Markus Pargmann <[email protected]> wrote: >> > spinlocked ranges should be small and not contain calls into huge >> > subfunctions. Fix my mistake and just get the pointer to the socket >> > instead of doing everything with spinlock held. >> > >> > Reported-by: Mikulas Patocka <[email protected]> >> > Signed-off-by: Markus Pargmann <[email protected]> >> > --- >> > drivers/block/nbd.c | 18 ++++++++++-------- >> > 1 file changed, 10 insertions(+), 8 deletions(-) >> > >> > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c >> > index 0b892eed06a0..157bf3da876e 100644 >> > --- a/drivers/block/nbd.c >> > +++ b/drivers/block/nbd.c >> > @@ -173,20 +173,22 @@ static void nbd_end_request(struct nbd_device *nbd, >> > struct request *req) >> > */ >> > static void sock_shutdown(struct nbd_device *nbd) >> > { >> > + struct socket *sock; >> > + >> > spin_lock_irq(&nbd->sock_lock); >> > + sock = nbd->sock; >> > + nbd->sock = NULL; >> > + spin_unlock_irq(&nbd->sock_lock); >> > >> > - if (!nbd->sock) { >> > - spin_unlock_irq(&nbd->sock_lock); >> > + if (!sock) >> > return; >> > - } >> > + >> > + del_timer(&nbd->timeout_timer); >> > >> > dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n"); >> > - kernel_sock_shutdown(nbd->sock, SHUT_RDWR); >> > - sockfd_put(nbd->sock); >> > - nbd->sock = NULL; >> > - spin_unlock_irq(&nbd->sock_lock); >> > + kernel_sock_shutdown(sock, SHUT_RDWR); >> > + sockfd_put(sock); >> > >> > - del_timer(&nbd->timeout_timer); >> > } >> > >> > static void nbd_xmit_timeout(unsigned long arg) >> >> I was concerned about nbd_xmit_timeout as well. There's also a call to >> kernel_sock_shutdown, >> while holding the spin_lock in the timeout. The above is ok for >> sock_shutdown but some kind of change >> is also required in nbd_xmit_timeout as well. My patch addressed both these. > > Oh I see thanks. Seems there is some duplicate code in > nbd_xmit_timeout and sock_shutdown. I think nbd_xmit_timeout could > perhaps be simplified? > > static void nbd_xmit_timeout(unsigned long arg) > { > struct nbd_device *nbd = (struct nbd_device *)arg; > > if (list_empty(&nbd->queue_head)) > return; > > nbd->timedout = true; > dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down > connection\n"); > > sock_shutdown(nbd);
Even then, the timeout is non-process context so there will still be a might_sleep warning. So sock_shutdown itself can be simplified, as you posted in earlier patch, but I don't think sock_shutdown should be called from non-process context[?]. > } > > Thanks, > > Markus > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- ---P.K.S ------------------------------------------------------------------------------ Mobile security can be enabling, not merely restricting. Employees who bring their own devices (BYOD) to work are irked by the imposition of MDM restrictions. Mobile Device Manager Plus allows you to control only the apps on BYO-devices by containerizing them, leaving personal data untouched! https://ad.doubleclick.net/ddm/clk/304595813;131938128;j _______________________________________________ Nbd-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/nbd-general
