On Tue, 3 Jan 2012, Mikulas Patocka wrote: > > > 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@xxxxxxxxxx> > > > CC: stable@xxxxxxxxxx > > > > 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 Sorry, I accidentally linked to the message you were responding to. The point is that there are some users of get_super that need to get superblock even if it's frozen and other users of get_super that must not get a frozen superblock. So I made a bool parameter to distinguish these cases. Do you have some other ideas? Mikulas > 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... > > > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
