Messages in this thread |  | | | Date | Tue, 3 Jan 2012 13:22:22 -0500 (EST) | | From | Mikulas Patocka <> | | Subject | Re: [PATCH] deadlock with suspend and quotas |
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On Tue, 3 Jan 2012, Al Viro wrote:
> On Fri, Nov 25, 2011 at 03:25:16PM -0500, Mikulas Patocka wrote: > > > The following patch fixes the deadlock. When the quota subsystem takes s_umount, > > it checks if the filesystem is frozen. If it is, we drop s_umount, wait for > > the filesystem to resume and retry. > > > > Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> > > CC: stable@kernel.org > > So basically you want a variant of get_super() that would get you a > superblock for this bdev, locked and unfrozen? Fair enough, but > * that should be a proper helper in super.c, rather than > open-coded in fs/quota/quota.c, of all places > * what about other existing callers get_super() and its friends?
Hi
You can look at that functionality here: I've already made a patch that has it: https://www.redhat.com/archives/dm-devel/2011-November/msg00151.html
Basically, the patch introduces a function down_read_s_umount, which takes s_umount for read, but makes sure that the filesystem is not frozen. Then, it adds a boolean parameter to get_super() which tells get_super() that it should wait for unfreeze (i.e. call "down_read_s_umount" isntead of "down_read(&sb->s_umount)").
Mikulas
> and while we are at it, why in damnation name is it exported? The only > caller outside of core VFS is under #if 0... >
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