Warning during GC, resulting in to Magic Bitmask Error for JFFS2.

Warning during GC, resulting in to Magic Bitmask Error for JFFS2.

[Niraj Maheshwari]

Hi,

I am using Linux 2.6.10 kernel and  mounting the JFFS2 partition from
Intel NOR flash after booting the system. These error doesn't appear
always, it only comes
if we follow the steps explained below.

1. Boot the system and mount the JFFS2 partition. It happens without
any error at the first time.
2. Copy enough data to JFFS2 mounted directory so it becomes full.
3. Once the mounted partition is full, we delete few files from the partition.
    We get following warning when we do that.
    "jffs2_reserve_space(): Low on dirty space to GC, but it's a
deletion. Allowing.."
4. Now again reboot the system now we get below errors while mounting the 
   JFFS2 partition.

  jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at
0x0013cad4: 0xa6fc   instead
  jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at
0x0013cad8: 0x6e03 instead
jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0013cadc: 0x70cd in
stead
jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0013cae0: 0x0e5f in
stead
jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0013cae4: 0x75aa in
stead
jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0013cae8: 0xca04 in
stead
jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0013caec: 0x5aec in
stead

It would be really great if you can help me out to fix this problem. 
Pl. note that i am only using the JFFS2 support which has come along
with the 2.6.10 Kernel.

Pl. help me out to fix this problem.

Thanks
Niraj

Re: Warning during GC, resulting in to Magic Bitmask Error for JFFS2.

[Artem B. Bityuckiy]

> I am using Linux 2.6.10 kernel and  mounting the JFFS2 partition from
> Intel NOR flash after booting the system. These error doesn't appear
> always, it only comes
> if we follow the steps explained below.
> 
Try the last MTD from CVS please.

-- 
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.

Re: Warning during GC, resulting in to Magic Bitmask Error for JFFS2.

[Niraj Maheshwari]

Hi Artem/All,

I tried using 5th May, 2005 snapshot and applied the patch on Linux
Kernel 2.6.10 but still the same problem gets repeated 3 out of 5
times if you follow the same steps and it's pretty much consistent.

When i delete a file when the JFFS2 partition is full, i get an error 
"jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion.
Allowing."

But if i give the command "sync" then it works fine after booting
otherwise it gives me following error for sometime and then it mounts
the JFFS2 partition.

jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00540004:
0x0040 in stead

Any idea on this problem ? Has anyone faced this problem ?

Thanks
Niraj

On 5/6/05, Artem B. Bityuckiy <dedekind@infradead.org> wrote:
> > I am using Linux 2.6.10 kernel and  mounting the JFFS2 partition from
> > Intel NOR flash after booting the system. These error doesn't appear
> > always, it only comes
> > if we follow the steps explained below.
> >
> Try the last MTD from CVS please.
> 
> --
> Best Regards,
> Artem B. Bityuckiy,
> St.-Petersburg, Russia.
> 
>

Re: Warning during GC, resulting in to Magic Bitmask Error for JFFS2.

[Artem B. Bityuckiy]

> When i delete a file when the JFFS2 partition is full, i get an error 
> "jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion.
> Allowing."
I'm not sure printing this message is a brilliant idea, but it is
harmless. Deletion in JFFS2 means writing new deletion nodes, which also
require some space. Your filesystem is stuffed fully, and there is no
space to write. But since writes are *deletions*, JFFS2 uses the blicks
which are reserved for GC to write these deletion nodes. And it prints
the messages you've observed.

> But if i give the command "sync" then it works fine after booting
> otherwise it gives me following error for sometime and then it mounts
> the JFFS2 partition.
Surely you reboot your board uncleanly, i.e., without cleanly unmounting
it?

-- 
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.