>> On Sat, 16 Jan 2010 10:58:30 +0100 >> Fran__ois Figarola <francois.figarola@xxxxxxxxxxxx> wrote: >>> Since I've tried to boot 2.6.32.x kernel, my system hangs during the >>> boot process, and I think it could be related to the problem reported >>> earlier by Megastorage (http://lkml.org/lkml/2010/1/10/92). >>> >>> The hardware is a Dell PowerEdge 2950 which runs fine with the >>> 2.6.31.x kernel series (actually running with the latest 2.6.31.11), >>> and the system is debian etch. >>> >>> Here is the trace of the bug I've got (using netconsole) with a >>> 2.6.32.3 kernel : >>> >>> BUG: Dentry ffff880667690000{i=41a46,n=sleep} still in use (8) >>> [unmount of ext3 dm-4] >>> ------------[ cut here ]------------ >>> kernel BUG at fs/dcache.c:670! I can reproduce this when suspend/resume read-only mounted dm device. When MS_RDONLY, both freeze_bdev and thaw_bdev call deactivate_locked_super, which seems wrong. The change was introduced with the commit below: commit 4504230a71566785a05d3e6b53fa1ee071b864eb Author: Christoph Hellwig <hch@xxxxxx> Date: Mon Aug 3 23:28:35 2009 +0200 freeze_bdev: grab active reference to frozen superblocks With the attached patch, both remount-ro and remount-rw are rejected as EBUSY on freezed device as expected. Christoph, do you think this is the right fix? -- Jun'ichi Nomura, NEC Corporation If MS_RDONLY, freeze_bdev should just up_write(s_umount) instead of deactivate_locked_super(). Also, keep sb->s_frozen consistent so that remount can check the frozen state. Signed-off-by: Jun'ichi Nomura <j-nomura@xxxxxxxxxxxxx> diff --git a/fs/block_dev.c b/fs/block_dev.c index 73d6a73..600261f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -246,7 +246,9 @@ struct super_block *freeze_bdev(struct block_device *bdev) if (!sb) goto out; if (sb->s_flags & MS_RDONLY) { - deactivate_locked_super(sb); + sb->s_frozen = SB_FREEZE_TRANS; + smp_wmb(); + up_write(&sb->s_umount); mutex_unlock(&bdev->bd_fsfreeze_mutex); return sb; } @@ -307,7 +309,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb) BUG_ON(sb->s_bdev != bdev); down_write(&sb->s_umount); if (sb->s_flags & MS_RDONLY) - goto out_deactivate; + goto out_unfrozen; if (sb->s_op->unfreeze_fs) { error = sb->s_op->unfreeze_fs(sb); @@ -321,11 +323,11 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb) } } +out_unfrozen: sb->s_frozen = SB_UNFROZEN; smp_wmb(); wake_up(&sb->s_wait_unfrozen); -out_deactivate: if (sb) deactivate_locked_super(sb); out_unlock: -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
