F16: Kernel bug with USB disks ?

[J. Randall Owens]

On 03/26/2012 06:05 AM, Terry Barnaby wrote:
> Hi,
> 
> I am using the latest F16 kernel: 3.3.0-4.fc16.i686.PAE and am having
> problems with a MicroSD card connected to a USB card reader. This has
> been working fine until recently (at least in F14 on the same hardware).
> 
> The problem is that "umount" does not appear to be working correctly.
> I have an ext3 file system on the card. I can mount it, and I can copy
> files to it. However when I use the "umount ..." command it returns
> instantly (should sync the files to the card). The system says the card
> is unmounted (at least it is not listed with mount, df etc).
> 
> However if I run sync, there is a lot of disk activity to the card ...
> 
> Also if I try and run "mkfs" it says the device in in use ...
> If I mount a blank card it lists the files present on the previous card ...
> 
> This sounds like a nasty kernel bug ...
> Anyone else seen this ?

I thought I'd noticed something like this with 3.2.x kernels also; I
couldn't narrow it down more than that.  In my case, it's a USB external
HDD.  After unmounting, I have an old habit of running 3 syncs in one
line.  And lately, I've noticed that I don't even get that disk activity
until I give it a second trio of syncs, which certainly doesn't seem right.
Let me check right now with 3.3.0-4...  Odd, now I do get the activity
at about the same time as the umount, and no further activity when I
issue the syncs.  Seems to be the opposite of what you've reported.

-- 
J. Randall Owens | http://www.ghiapet.net/