Messages in this thread |  | | From | "Adam J. Richter" <> | Date | Tue, 27 Aug 2002 05:40:52 -0700 | Subject | Re: Loop devices under NTFS |
| |
At 05:48 27/08/02, Andre Bonin wrote: >"mount -o loop -r -t iso9660 /mnt/win_d/Source/Iso/Red\ Hat\ >7.3/valhalla-i386-disc1.iso /mnt/rh7.3/cd1" > >It gives me an error >"ioctl: LOOP_SET_FD: Invalid argument"
I believe that NTFS does not provide address_space_operations->{prepare,commit}_write for plain files, so the version of loop.c in stock 2.5.31 will not work.
I posted an update for loop.c that I posted on August 15th: ( http://marc.theaimsgroup.com/?l=linux-kernel&m=102941520919910&w=2 ). That update included a hack (originally conceived by Andrew Morton and originally implemented Jari Ruusu) to use file_operations->{read,write} for mounting files on file systems that do not provide {prepare,commit}_write, although this involves an extra data copy if a transformation (such as encryption) is selected.
I submitted the loop.c update to Linus at least a week ago, but I have not seen it appear in ftp://ftp.kernel.org/pub/linux/kernel/people/dwmw2/bk-2.5.
Side note:
There are only a few file systems that provide writable files without aops->{prepare,commit}_write. I think they are just tmpfs, ntfs and intermezzo. If all file systems that provided writable files could be expected to provide {prepare,commit}_write, I could eliminate the file_ops->{read,write} code from loop.c. I wish I understood if there really is a need for a file system to be able to provide a writable random access file (as opposed to /dev/tty) that does not have aops->{prepare,commit}_write. I would be interesting in knowing if there is anything preventing implementation of {prepare,commit}_wriet in ntfs.
Adam J. Richter __ ______________ 575 Oroville Road adam@yggdrasil.com \ / Milpitas, California 95035 +1 408 309-6081 | g g d r a s i l United States of America "Free Software For The Rest Of Us."
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |