Messages in this thread | | | From | Richard Waltham <> | Subject | Re: ide/scsi cd-rom differences, ide ok, errors copying with scsi cd-rom | Date | Mon, 30 Jun 1997 14:49:04 +0100 (BST) |
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Hi Gerard,
I think it was a mistake mentioning the additional patches and the oops. The main problem for me at the moment is the SCSI CD-Rom errors. The oops and subsequent errors are almost certainly because of that although I suppose if everything was OK they wouldn't happen either.
Something is broken in the SCSI CD-ROM driver and I should have concentrated on that.
The same sort of errors happen with a plain 2.0.29 kernel and SCSI CD-Rom but copying with an IDE CD-Rom drive is perfectly OK.
Gerard Roudier wrote: > > > > The patch against pre-2.0.30-2 I've sent that tries to fix the memory > problem, allows 1 recursion involving get_more_buffer_headers() in order > not to use GFP_ATOMIC allocation. That is a bit dangerous for the kernel > stacks and obviously I did'nt test it in all cases. The right approach is > probably to use GFP_ATOMIC allocation for buffer headers at least for > page IO but being given that: > - min_free_pages = memory size / 128 = 0.78 % of the whole memory, > - sizeof(buffer_head) is about 76 bytes for x86 -> 80/1024 = 7.8 % of the > same memory, > starting asynchronously page IOs for 10% of the whole memory can eat all > the reserved pages for buffer headers. The fact that buffers can be > allocated at ATOMIC priority also did'nt help. > In my opinion, some changes are to be done in the kernel, in order not to > do too much asynchronous IO for pages when free memory becomes too low. > Such changes in the kernel are beyond my skills. > > Gerard.
I'm not really sure what all this means - I just happened to be using a kernel with pre-patch-2.0.31-2 and your patch when I first noticed the errors while copying CD's.
I had been checking some other operations and just decided to try a copy to see what happened.
The messages are basically the same with 2.0.29 - and are from ../fs/isofs/inode.c
Structures used by inode.c seem to be set up incorrectly by the SCSI CD-Rom driver and is why the errors appear NOT because the CD is defective - isofs is lying - sorry, no it's not, it's being given incorrect information.
> > > > > > Warning: defective cdrom (volume sequence number). Enabling "cruft" mount option. > > File unit size != 0 for ISO file (954846). > > Interleaved files not (yet) supported. > > File unit size != 0 for ISO file (934328). > > File unit size != 0 for ISO file (934438). > > File unit size != 0 for ISO file (1014204). > > File unit size != 0 for ISO file (862672). > > Interleaved files not (yet) supported. > > File unit size != 0 for ISO file (870830). > > File unit size != 0 for ISO file (860580). > > File unit size != 0 for ISO file (813508). > > kmalloc of too large a block (67702033 bytes). > > Interleaved files not (yet) supported. > > > >
-- Richard Waltham | Work: richard@digtalinterface.demon.co.uk At home in | Home: dormouse@farsrobt.demon.co.uk Southampton UK | Compuserve 100421.1276
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