Re: [PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread NeilBrown
On Tue, 11 Mar 2014 21:19:24 -0700 Andrew Morton wrote: > On Wed, 12 Mar 2014 14:10:25 +1100 NeilBrown wrote: > > > On Tue, 11 Mar 2014 20:03:31 -0700 Andrew Morton > > wrote: > > > > > On Wed, 12 Mar 2014 13:36:38 +1100 NeilBrown wrote: > > > > > > > > > > > The md driver currently

Re: [PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread Andrew Morton
On Wed, 12 Mar 2014 14:10:25 +1100 NeilBrown wrote: > On Tue, 11 Mar 2014 20:03:31 -0700 Andrew Morton > wrote: > > > On Wed, 12 Mar 2014 13:36:38 +1100 NeilBrown wrote: > > > > > > > > The md driver currently supports 'poll' on /proc/mdstat. > > > This is unsafe as if the md-mod module is

Re: [PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread NeilBrown
On Tue, 11 Mar 2014 20:03:31 -0700 Andrew Morton wrote: > On Wed, 12 Mar 2014 13:36:38 +1100 NeilBrown wrote: > > > > > The md driver currently supports 'poll' on /proc/mdstat. > > This is unsafe as if the md-mod module is removed while a 'poll' > > or 'select' is outstanding on /proc/mdstat,

Re: [PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread Andrew Morton
On Wed, 12 Mar 2014 13:36:38 +1100 NeilBrown wrote: > > The md driver currently supports 'poll' on /proc/mdstat. > This is unsafe as if the md-mod module is removed while a 'poll' > or 'select' is outstanding on /proc/mdstat, an oops occurs > when the syscall completes. > poll_freewait() will

[PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread NeilBrown
The md driver currently supports 'poll' on /proc/mdstat. This is unsafe as if the md-mod module is removed while a 'poll' or 'select' is outstanding on /proc/mdstat, an oops occurs when the syscall completes. poll_freewait() will call remove_wait_queue() on a wait_queue_head_t which was local to

[PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread NeilBrown
The md driver currently supports 'poll' on /proc/mdstat. This is unsafe as if the md-mod module is removed while a 'poll' or 'select' is outstanding on /proc/mdstat, an oops occurs when the syscall completes. poll_freewait() will call remove_wait_queue() on a wait_queue_head_t which was local to

Re: [PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread Andrew Morton
On Wed, 12 Mar 2014 13:36:38 +1100 NeilBrown ne...@suse.de wrote: The md driver currently supports 'poll' on /proc/mdstat. This is unsafe as if the md-mod module is removed while a 'poll' or 'select' is outstanding on /proc/mdstat, an oops occurs when the syscall completes. poll_freewait()

Re: [PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread NeilBrown
On Tue, 11 Mar 2014 20:03:31 -0700 Andrew Morton a...@linux-foundation.org wrote: On Wed, 12 Mar 2014 13:36:38 +1100 NeilBrown ne...@suse.de wrote: The md driver currently supports 'poll' on /proc/mdstat. This is unsafe as if the md-mod module is removed while a 'poll' or 'select' is

Re: [PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread Andrew Morton
On Wed, 12 Mar 2014 14:10:25 +1100 NeilBrown ne...@suse.de wrote: On Tue, 11 Mar 2014 20:03:31 -0700 Andrew Morton a...@linux-foundation.org wrote: On Wed, 12 Mar 2014 13:36:38 +1100 NeilBrown ne...@suse.de wrote: The md driver currently supports 'poll' on /proc/mdstat. This is

Re: [PATCH] poll/wait/md: allow module to safely support 'poll' on /proc files

2014-03-11 Thread NeilBrown
On Tue, 11 Mar 2014 21:19:24 -0700 Andrew Morton a...@linux-foundation.org wrote: On Wed, 12 Mar 2014 14:10:25 +1100 NeilBrown ne...@suse.de wrote: On Tue, 11 Mar 2014 20:03:31 -0700 Andrew Morton a...@linux-foundation.org wrote: On Wed, 12 Mar 2014 13:36:38 +1100 NeilBrown