Messages in this thread | | | Date | Sun, 17 Jun 2012 18:28:48 -0700 | From | jdow <> | Subject | Re: Partitions: Amiga RDB partition on 2 TB disk way too big, while OK in AmigaOS 4.1 |
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On 2012/06/17 14:20, Martin Steigerwald wrote: > Am Sonntag, 17. Juni 2012 schrieb jdow: >> On 2012/06/17 09:36, Geert Uytterhoeven wrote: >>> On Sun, Jun 17, 2012 at 2:58 PM, Martin Steigerwald > <Martin@lichtvoll.de> wrote: >>>> Am Sonntag, 17. Juni 2012 schrieb jdow: >>>> | JXFS 64 bit file system >>>> | >>>> | With AmigaOS 4.x a new file system has been introduced called >>>> | JXFS. It is a totally new 64 bit file system that supports >>>> | partitions up to 16 TB in size. It is a modern journalling file >>>> | system, which means that it reduces data loss if data writes to >>>> | the disk are interrupted. It is the fastest and most reliable >>>> | file system ever created for AmigaOS. >>>> >>>> http://www.amigaos.net/content/1/features >>>> >>>> Well I asked AmigaOS 4 developers about this issue as well. Lets see >>>> what they say about 2 TB limits. >>> >>> 16 TB = 2 TB * 8. Perhaps they increased the block size from 512 to >>> 4096? >>> >>> block/partitions/amiga.c reads the block size from >>> RigidDiskBlock.rdb_BlockBytes, >>> but after conversion to 512-byte blocks, all further calculations are >>> done on "int", so it will overflow for disks larger than 2 TiB. >>> >>> Note that in your profile-binary.img, the field is 0x200, i.e. 512 >>> bytes per block, >>> so I'll have to get a deeper look into your RDB first... > […] >> Note that the work I did on the Linux RDB code eons ago took full >> cognizance of the physical and virtual block sizes. > […] >> I've asked Martin for a digital copy of his RDBs and what he thinks the >> partition(s) should look like. I should also be told whether the disk >> is supposed to be solely Amiga OSs or not. I gather it's not. > > Its all in the bug report. profile-binary.img should be it. > > Its small so I attach it. > > Meanwhile I try to get the currently supported maximum disk size out from > the OS 4 developers. Maybe JXFS is playing tricks that other filesystems do > not play or simply has a different implementation. > > Thanks,
I've sent Jens a proposed fix changing these lines in amiga.c. ===8<--- was struct PartitionBlock *pb; int start_sect, nr_sects, blk, part, res = 0; int blksize = 1; /* Multiplier for disk block size */ ===8<--- becomes changing line 338 into lines 338-339 struct PartitionBlock *pb; sector_t start_sect, nr_sects; int blk, part, res = 0; int blksize = 1; /* Multiplier for disk block size */ ===8<---
(I'm working without proper tools at the moment or I'd make a real diff. Sorry.)
This fix may not be complete. The RDBs contain provisions for describing the physical disk block size and how many physical blocks are used in a file system's logical blocks. This MAY not work quite right large physical block sizes.
{^_^} Joanne Dow -- 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/
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