Re: [RFC] vfs: avoid sb->s_umount lock while changing bind-mount flags

2013-09-30 Thread Aditya Kali
On Mon, Sep 30, 2013 at 1:03 PM, Al Viro wrote: > On Mon, Sep 30, 2013 at 11:13:23AM -0700, Aditya Kali wrote: >> +Ted Ts'o, Tejun Heo, Jens Axboe >> >> >> On 09/30/2013 10:54 AM, Aditya Kali wrote: >> >Hi Al and other fs-developers, >> > >> >Please let me know what you think about this patch. > >

Re: [RFC] vfs: avoid sb->s_umount lock while changing bind-mount flags

2013-09-30 Thread Al Viro
On Mon, Sep 30, 2013 at 11:13:23AM -0700, Aditya Kali wrote: > +Ted Ts'o, Tejun Heo, Jens Axboe > > > On 09/30/2013 10:54 AM, Aditya Kali wrote: > >Hi Al and other fs-developers, > > > >Please let me know what you think about this patch. Don't top-post, please... What prevents a race between MS

Re: [RFC] vfs: avoid sb->s_umount lock while changing bind-mount flags

2013-09-30 Thread Aditya Kali
+Ted Ts'o, Tejun Heo, Jens Axboe On 09/30/2013 10:54 AM, Aditya Kali wrote: Hi Al and other fs-developers, Please let me know what you think about this patch. Thanks, > On Thu, Sep 19, 2013 at 1:13 PM, Aditya Kali wrote: >> >> >> On 09/16/2013 07:40 PM, Al Viro wrote: >>> >>> On Mon, Sep

Re: [RFC] vfs: avoid sb->s_umount lock while changing bind-mount flags

2013-09-30 Thread Aditya Kali
Hi Al and other fs-developers, Please let me know what you think about this patch. Thanks, -- Aditya On Thu, Sep 19, 2013 at 1:13 PM, Aditya Kali wrote: > > > On 09/16/2013 07:40 PM, Al Viro wrote: >> >> On Mon, Sep 16, 2013 at 10:42:30AM -0700, Aditya Kali wrote: >>> >>> During remount of a b

Re: [RFC] vfs: avoid sb->s_umount lock while changing bind-mount flags

2013-09-19 Thread Aditya Kali
On 09/16/2013 07:40 PM, Al Viro wrote: On Mon, Sep 16, 2013 at 10:42:30AM -0700, Aditya Kali wrote: During remount of a bind mount (mount -o remount,bind,ro,... /mnt/mntpt), we currently take down_write(&sb->s_umount). This causes the remount operation to get blocked behind writes occuring on

Re: [RFC] vfs: avoid sb->s_umount lock while changing bind-mount flags

2013-09-16 Thread Al Viro
On Mon, Sep 16, 2013 at 10:42:30AM -0700, Aditya Kali wrote: > During remount of a bind mount (mount -o remount,bind,ro,... /mnt/mntpt), > we currently take down_write(&sb->s_umount). This causes the remount > operation to get blocked behind writes occuring on device (possibly > mounted somewhere e

[RFC] vfs: avoid sb->s_umount lock while changing bind-mount flags

2013-09-16 Thread Aditya Kali
During remount of a bind mount (mount -o remount,bind,ro,... /mnt/mntpt), we currently take down_write(&sb->s_umount). This causes the remount operation to get blocked behind writes occuring on device (possibly mounted somewhere else). We have observed that simply trying to change the bind-mount fr