infinite loop when copying to ext2fs / ext2_new_block()

[Jakub Siroky]

This is the dump when I place a panic call inside the loop and then use
kgdb:

Panic String: ext2_new_block: bit already set for block 5346

panic() at panic+0x17a - added otherwise loop occurs, especially when
the volume is almost full

ext2_new_block() at ext2_new_block+0x892
ext2_alloc() at ext2_alloc+0x189
ext2_balloc() at ext2_balloc+0x1f3
ext2_write() at ext2_write+0x178
VOP_WRITE_APV() at VOP_WRITE_APV+0x131
vn_write() at vn_write+0x1ce
dofilewrite() at dofilewrite+0x85
kern_writev() at kern_writev+0x4c
write() at write+0x54
syscall() at syscall+0x1f6
Xfast_syscall() at Xfast_syscall+0xab
--- syscall (4, FreeBSD ELF64, write), rip = 0x800713d3c, rsp =
0x7fffffffe948, rbp = 0x19df2 ---

Regards,
Jakub

On Sat, 19 Jan 2008 16:44:34 +0100
Kris Kennaway <kris at FreeBSD.org> wrote:

> Kris Kennaway wrote:
> > Jakub Siroky wrote:
> >> I have two large ext2fs partitions (368 and 313GB) to hold data
> >> shared between several OSes. While there were no problems on
> >> 6-STABLE branch I was quite disappointed after upgrade to
> >> 7-STABLE. Whenever I copy/write to ext2fs partition the system
> >> freezes totally without crashdump. So I set debugging settings to
> >> kernel config (DEBUG,WITNESS,..) and in console I reproduced error
> >> situation ending with full screen of unstoppable running text with
> >> lot of memory addresses and a few recognisable words: 'new block
> >> bit set for ext already' - again with no crashdump. Then I have
> >> formatted 1GB partition with ext2fs and the problem on this small
> >> partition appears only sometimes. 
> > 
> > OK, I am able to reproduce this.
> > 
> > Kris
> > 
> 
> Is anyone able to look at this?  I could not spot a candidate change 
> that has not been merged to 6.x.
> 
> Kris