Re: [Pramfs-devel] mount hangs

[Michael N. <na...@ac...>]

>>> Sorry - I am new to mailing lists.  Reformatted previous note to fit margins.

I am running the v1.2.5 level of pramfs on an older 2.6.37 kernel, and am encountering a problem trying
to implement conditional logic to determine if a prior pramfs filesystem is intact and initialize a new one
if it is not.  This basic sequence works fine:

   0) start with randomized SDRAM (after long power-off)
   1) mount -t pramfs -o physaddr=0x21e00000,init=0x200000 none /mnt/pramfs
   2) write some files to the /mnt/pramfs folder
   3) reboot
   4) mount -t pramfs -o physaddr=0x21e00000 none /mnt/pramfs
   5) verify files written in (2) are still there and intact

The problem is demonstrated with either of these sequences:

   0) start with randomized SDRAM (after long power-off)
   1) mount -t pramfs -o physaddr=0x21e00000 none /mnt/pramfs  <--  fails as expected
   2) mount -t pramfs -o physaddr=0x21e00000,init=0x20000 none /mnt/pramfs  <-- hangs

   0) start with randomized SDRAM (after long power-off)
   1) mount -t pramfs -o physaddr=0x21e00000 none /mnt/pramfs  <--  fails as expected
   2) umount /mnt/pramfs
   3) mount -t pramfs -o physaddr=0x21e00000,init=0x20000 none /mnt/pramfs  <-- hangs

I have verified that umount removes the mapping in /proc/iomap in the 2nd case.  It is odd that the failed
mount didn't remove the mapping itself as part of error cleanup - which is probably part of the issue somehow.

Anyhow, is this expected behavior?  Is it a problem that has been fixed moving forward from the older
code-base I am building from (v1.2.5)?  Any other suggestions on how to debug or resolve?

- Michael