Messages in this thread | | | Date | Wed, 8 Nov 2006 02:30:39 +0000 | From | Alasdair G Kergon <> | Subject | Re: [PATCH 2.6.19 5/5] fs: freeze_bdev with semaphore not mutex |
| |
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).
Try: while process generating I/O to filesystem on LVM issue dmsetup suspend --nolockfs (which the lvm2 tools often do) try your freeze_filesystems()
Maybe: don't allow freeze_filesystems() to run when the system is in that state; or, use device-mapper suspend instead of freeze_bdev directly where dm is involved; or skip dm devices that are already frozen - all with appropriate dependency tracking to process devices in the right order.
Alasdair -- agk@redhat.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |