tree 9d666e849cdf9c495d446df242d87e798d4baec9
parent 1ffb96c587fa2af0d690dc3548a4a781c477bfb7
author Nick Piggin <npiggin@suse.de> 1174978508 +0200
committer Jens Axboe <jens.axboe@oracle.com> 1174978508 +0200

1/2 splice: dont steal

Stealing pages with splice is problematic because we cannot just insert
an uptodate page into the pagecache and hope the filesystem can take care
of it later.

We also cannot just ClearPageUptodate, then hope prepare_write does not
write anything into the page, because I don't think prepare_write gives
that guarantee.

Remove support for SPLICE_F_MOVE for now. If we really want to bring it
back, we might be able to do so with a the new filesystem buffered write
aops APIs I'm working on. If we really don't want to bring it back, then
we should decide that sooner rather than later, and remove the flag and
all the stealing infrastructure before anybody starts using it.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>