On Wednesday, 8 November 2006 21:48, Nigel Cunningham wrote: > Hi. > > On Wed, 2006-11-08 at 13:10 +0100, Rafael J. Wysocki wrote: > > On Wednesday, 8 November 2006 03:30, Alasdair G Kergon wrote: > > > On Tue, Nov 07, 2006 at 11:49:51PM +0000, Alasdair G Kergon wrote: > > > > I hadn't noticed that -mm patch. I'll take a look. > > > > > > swsusp-freeze-filesystems-during-suspend-rev-2.patch > > > > > > I think you need to give more thought to device-mapper > > > interactions here. If an underlying device is suspended > > > by device-mapper without freezing the filesystem (the > > > normal state) and you issue a freeze_bdev on a device > > > above it, the freeze_bdev may never return if it attempts > > > any synchronous I/O (as it should). > > > > Well, it looks like the interactions with dm add quite a bit of > > complexity here. > > > > > Try: > > > while process generating I/O to filesystem on LVM > > > issue dmsetup suspend --nolockfs (which the lvm2 tools often do) > > > try your freeze_filesystems() > > > > Okay, I will. > > > > > Maybe: don't allow freeze_filesystems() to run when the system is in that > > > state; > > > > I'd like to avoid that (we may be running out of battery power at this point). > > > > > or, use device-mapper suspend instead of freeze_bdev directly where > > > dm is involved; > > > > How do I check if dm is involved? > > > > > or skip dm devices that are already frozen - all with > > > appropriate dependency tracking to process devices in the right order. > > > > I'd prefer this one, but probably the previous one is simpler to start with. > > Shouldn't we just go for the right thing to begin with? Otherwise we'll > just make more problems for ourselves later. > > If we do this last one, I guess we want to do something like I was doing > before (creating a list of the devices we've frozen)? Well, the frozen superblocks have MS_FROZEN set. What the other list is needed for? Rafael -- You never change things by fighting the existing reality. R. Buckminster Fuller -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
