[lkml]   [2002]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] remove 2TB block device limit
>>>>> "Andrew" == Andrew Morton <> writes:

Andrew> Peter Chubb wrote:
>> ...
Christoph> - why is the get_block block argument a sector_t? It
Christoph> presents a logical filesystem block which usually is larger
Christoph> than the sector, not to mention that for the usual
Christoph> blocksize == PAGE_SIZE case a ulong is enough as that is
Christoph> the same size the pagecache limit triggers.
>> For filesystems that *can* handle logical filesystem blocks beyond
>> the 2^32 limit (i.e., that use >32bit offsets in their on-disc
>> format), the get_block() argument has to be > 32bits long. At the
>> moment that's only JFS and XFS, but reiserfs version 4 looks as if
>> it might go that way. We'll need this especially when the
>> pagecache limit is gone.

Andrew> I think Christoph's point is that a pagecache index is not a
Andrew> sector number. We agree that we need to plan for taking it to
Andrew> 64 bits, but it should be something different. Like
Andrew> pageindex_t, or whatever.

I'll let Christoph speak for himself, but my point is that
get_block() is an interface exported from the filesystem. It should
be possible to specify any logical block number that the filesystem
supports. That the current VM system on 32-bit machines will never
request a block beyond 2^32 is a (one-day-soon-to-be-removed) current

Peter C
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:26    [W:0.059 / U:10.732 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site