From: David Chinner Date: Mon, 12 Feb 2007 08:51:41 +0000 (-0800) Subject: [PATCH] Make BH_Unwritten a first class bufferhead flag V2 X-Git-Tag: v2.6.21-rc1~274^2~208 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=33a266dda9fbbe72dd978a451a8ee33c59da5e9c;p=pandora-kernel.git [PATCH] Make BH_Unwritten a first class bufferhead flag V2 Currently, XFS uses BH_PrivateStart for flagging unwritten extent state in a bufferhead. Recently, I found the long standing mmap/unwritten extent conversion bug, and it was to do with partial page invalidation not clearing the unwritten flag from bufferheads attached to the page but beyond EOF. See here for a full explaination: http://oss.sgi.com/archives/xfs/2006-12/msg00196.html The solution I have checked into the XFS dev tree involves duplicating code from block_invalidatepage to clear the unwritten flag from the bufferhead(s), and then calling block_invalidatepage() to do the rest. Christoph suggested that this would be better solved by pushing the unwritten flag into the common buffer head flags and just adding the call to discard_buffer(): http://oss.sgi.com/archives/xfs/2006-12/msg00239.html The following patch makes BH_Unwritten a first class citizen. Signed-off-by: Dave Chinner Acked-by: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed