From 032c09d76cdb448484859cc84dac4bba8f5f8f14 Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hugh@veritas.com>
Date: Fri, 2 Dec 2005 15:59:59 +0000
Subject: [SCSI] sg and st unmap_user_pages allow PageReserved
2.6.15-rc1 made sg's st_unmap_user_pages and st's sgl_unmap_user_pages
BUG on a PageReserved page. But that's wrong: they could be unmapping
the ZERO_PAGE, which is marked PG_reserved; and perhaps others (while
get_user_pages is still permitted on VM_PFNMAP areas - that may change).
More change is needed here: sg claims to dirty even pages written from,
and st claims not to dirty even pages read into; and SetPageDirty is not
adequate for this nowadays. Fixes to those follow in a later patch: for
the moment just fix the 2.6.15 regression.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
---
drivers/scsi/sg.c | 2 --
drivers/scsi/st.c | 2 --
2 files changed, 4 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 72ec59456e..6de7ff9faf 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1878,8 +1878,6 @@ st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
for (i=0; i < nr_pages; i++) {
struct page *page = sgl[i].page;
- /* XXX: just for debug. Remove when PageReserved is removed */
- BUG_ON(PageReserved(page));
if (dirtied)
SetPageDirty(page);
/* unlock_page(page); */
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index b1056d290a..7ac6ea141f 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4525,8 +4525,6 @@ static int sgl_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_p
for (i=0; i < nr_pages; i++) {
struct page *page = sgl[i].page;
- /* XXX: just for debug. Remove when PageReserved is removed */
- BUG_ON(PageReserved(page));
if (dirtied)
SetPageDirty(page);
/* FIXME: cache flush missing for rw==READ
--
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