On Thu, Jun 18, 2015 at 02:16:19PM -0400, Mike Snitzer wrote: > On Thu, Jun 18 2015 at 2:08pm -0400, > Andi Kleen <andi@xxxxxxxxxxxxxx> wrote: > > > > Hmm, so you have a filesystem active on it too? > > > > I unmounted it before. > > > > > > > > > Also the VG removal did not work of course. > > > > > > Once you resolve the filesystem piece, from vgremove man page: > > > > > > "vgremove allows you to remove one or more volume groups. If one or > > > more physical volumes in the volume group are lost, consider vgreduce > > > --removemissing to make the volume group metadata consistent again." > > > > Well in any case there should not be WARN()s. > > Yes well I don't even know what WARN_ON you're hitting. You're running > a 4.0.4 fedora kernel. Which WARN_ON() is triggering? The > WARN_ON_ONCE() in bdev_write_inode()? -- likely since the only caller of > bdev_write_inode is __blkdev_put... > > /** > * write_inode_now - write an inode to disk > * @inode: inode to write to disk > * @sync: whether the write should be synchronous or not > * > * This function commits an inode to disk immediately if it is dirty. This is > * primarily needed by knfsd. > * > * The caller must either have a ref on the inode or must have set I_WILL_FREE. > */ > > So I have no idea why bdev_write_inode() is using WARN_ON_ONCE.. makes > since that write_inode_now() will fail if the disk no longer exists. SO > the WARN_ON_ONCE seems misplaced. > > Git blame shows its all hch's fault: > > 564f00f6c (Christoph Hellwig 2015-01-14 10:42:33 +0100 57) WARN_ON_ONCE(write_inode_now(inode, true)); > > 564f00f6c block_dev: only write bdev inode on close I can reproduce it too in a Fedora 22 virtual machine. I just have to do "umount <mnt>" after hot unplugging the virtIO disk. But it does not happen without lvm. If I create ext4 fs directly on /dev/vda1, then when disk goes way, fs automatically gets unmounted. But same does not happen when /dev/vda1 is added to a volume group and I carve out a logical volume and create and mount fs. In that case if I do umount after device has gone away, I can see above WARN(). And it does seem to be coming from. WARN_ON_ONCE(write_inode_now(inode, true)) If we failed to write back inode, then warning about it sounds right? What's wrong with that? Should it be just a kernel log of level KERN_WARN instead? Thanks Vivek -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
