]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
[PATCH] sg: use compound pages
authorNick Piggin <npiggin@suse.de>
Wed, 22 Mar 2006 08:08:30 +0000 (00:08 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Wed, 22 Mar 2006 15:54:01 +0000 (07:54 -0800)
commitf9aed0e2537174b95908f48b6052ae37196c9390
tree0b5cd42f36f08086f0258a753203b840123c9301
parenta6f563db09c54c80d80e9013182dc512a5e53d0f
[PATCH] sg: use compound pages

sg increments the refcount of constituent pages in its higher order memory
allocations when they are about to be mapped by userspace.  This is done so
the subsequent get_page/put_page when doing the mapping and unmapping does not
free the page.

Move over to the preferred way, that is, using compound pages instead.  This
fixes a whole class of possible obscure bugs where a get_user_pages on a
constituent page may outlast the user mappings or even the driver.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Douglas Gilbert <dougg@torque.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/scsi/sg.c