* FAILED: patch "[PATCH] xen/gntdev.c: Mark pages as dirty" failed to apply to 4.19-stable tree
@ 2020-10-31 10:03 gregkh
2021-01-01 17:25 ` [PATCH 4.19 bp] xen/gntdev.c: Mark pages as dirty Jinoh Kang
0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2020-10-31 10:03 UTC (permalink / raw)
To: jrdr.linux, boris.ostrovsky, david.vrabel, jgross, jhubbard; +Cc: stable
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 779055842da5b2e508f3ccf9a8153cb1f704f566 Mon Sep 17 00:00:00 2001
From: Souptick Joarder <jrdr.linux@gmail.com>
Date: Sun, 6 Sep 2020 12:21:53 +0530
Subject: [PATCH] xen/gntdev.c: Mark pages as dirty
There seems to be a bug in the original code when gntdev_get_page()
is called with writeable=true then the page needs to be marked dirty
before being put.
To address this, a bool writeable is added in gnt_dev_copy_batch, set
it in gntdev_grant_copy_seg() (and drop `writeable` argument to
gntdev_get_page()) and then, based on batch->writeable, use
set_page_dirty_lock().
Fixes: a4cdb556cae0 (xen/gntdev: add ioctl for grant copy)
Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1599375114-32360-1-git-send-email-jrdr.linux@gmail.com
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 64a9025a87be..1f32db7b72b2 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -720,17 +720,18 @@ struct gntdev_copy_batch {
s16 __user *status[GNTDEV_COPY_BATCH];
unsigned int nr_ops;
unsigned int nr_pages;
+ bool writeable;
};
static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt,
- bool writeable, unsigned long *gfn)
+ unsigned long *gfn)
{
unsigned long addr = (unsigned long)virt;
struct page *page;
unsigned long xen_pfn;
int ret;
- ret = get_user_pages_fast(addr, 1, writeable ? FOLL_WRITE : 0, &page);
+ ret = get_user_pages_fast(addr, 1, batch->writeable ? FOLL_WRITE : 0, &page);
if (ret < 0)
return ret;
@@ -746,9 +747,13 @@ static void gntdev_put_pages(struct gntdev_copy_batch *batch)
{
unsigned int i;
- for (i = 0; i < batch->nr_pages; i++)
+ for (i = 0; i < batch->nr_pages; i++) {
+ if (batch->writeable && !PageDirty(batch->pages[i]))
+ set_page_dirty_lock(batch->pages[i]);
put_page(batch->pages[i]);
+ }
batch->nr_pages = 0;
+ batch->writeable = false;
}
static int gntdev_copy(struct gntdev_copy_batch *batch)
@@ -837,8 +842,9 @@ static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch,
virt = seg->source.virt + copied;
off = (unsigned long)virt & ~XEN_PAGE_MASK;
len = min(len, (size_t)XEN_PAGE_SIZE - off);
+ batch->writeable = false;
- ret = gntdev_get_page(batch, virt, false, &gfn);
+ ret = gntdev_get_page(batch, virt, &gfn);
if (ret < 0)
return ret;
@@ -856,8 +862,9 @@ static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch,
virt = seg->dest.virt + copied;
off = (unsigned long)virt & ~XEN_PAGE_MASK;
len = min(len, (size_t)XEN_PAGE_SIZE - off);
+ batch->writeable = true;
- ret = gntdev_get_page(batch, virt, true, &gfn);
+ ret = gntdev_get_page(batch, virt, &gfn);
if (ret < 0)
return ret;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 4.19 bp] xen/gntdev.c: Mark pages as dirty
2020-10-31 10:03 FAILED: patch "[PATCH] xen/gntdev.c: Mark pages as dirty" failed to apply to 4.19-stable tree gregkh
@ 2021-01-01 17:25 ` Jinoh Kang
2021-01-04 10:25 ` Greg Kroah-Hartman
0 siblings, 1 reply; 3+ messages in thread
From: Jinoh Kang @ 2021-01-01 17:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Souptick Joarder, Boris Ostrovsky, David Vrabel, Juergen Gross,
John Hubbard, stable
From: Souptick Joarder <jrdr.linux@gmail.com>
commit 779055842da5b2e508f3ccf9a8153cb1f704f566 upstream.
There seems to be a bug in the original code when gntdev_get_page()
is called with writeable=true then the page needs to be marked dirty
before being put.
To address this, a bool writeable is added in gnt_dev_copy_batch, set
it in gntdev_grant_copy_seg() (and drop `writeable` argument to
gntdev_get_page()) and then, based on batch->writeable, use
set_page_dirty_lock().
Fixes: a4cdb556cae0 (xen/gntdev: add ioctl for grant copy)
Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1599375114-32360-1-git-send-email-jrdr.linux@gmail.com
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[jinoh: backport accounting for missing
commit 73b0140bf0fe ("mm/gup: change GUP fast to use flags rather than a write 'bool'")]
Signed-off-by: Jinoh Kang <jinoh.kang.kr@gmail.com>
---
drivers/xen/gntdev.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 9d8e02cfd480..3cfbec482efb 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -842,17 +842,18 @@ struct gntdev_copy_batch {
s16 __user *status[GNTDEV_COPY_BATCH];
unsigned int nr_ops;
unsigned int nr_pages;
+ bool writeable;
};
static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt,
- bool writeable, unsigned long *gfn)
+ unsigned long *gfn)
{
unsigned long addr = (unsigned long)virt;
struct page *page;
unsigned long xen_pfn;
int ret;
- ret = get_user_pages_fast(addr, 1, writeable, &page);
+ ret = get_user_pages_fast(addr, 1, batch->writeable, &page);
if (ret < 0)
return ret;
@@ -868,9 +869,13 @@ static void gntdev_put_pages(struct gntdev_copy_batch *batch)
{
unsigned int i;
- for (i = 0; i < batch->nr_pages; i++)
+ for (i = 0; i < batch->nr_pages; i++) {
+ if (batch->writeable && !PageDirty(batch->pages[i]))
+ set_page_dirty_lock(batch->pages[i]);
put_page(batch->pages[i]);
+ }
batch->nr_pages = 0;
+ batch->writeable = false;
}
static int gntdev_copy(struct gntdev_copy_batch *batch)
@@ -959,8 +964,9 @@ static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch,
virt = seg->source.virt + copied;
off = (unsigned long)virt & ~XEN_PAGE_MASK;
len = min(len, (size_t)XEN_PAGE_SIZE - off);
+ batch->writeable = false;
- ret = gntdev_get_page(batch, virt, false, &gfn);
+ ret = gntdev_get_page(batch, virt, &gfn);
if (ret < 0)
return ret;
@@ -978,8 +984,9 @@ static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch,
virt = seg->dest.virt + copied;
off = (unsigned long)virt & ~XEN_PAGE_MASK;
len = min(len, (size_t)XEN_PAGE_SIZE - off);
+ batch->writeable = true;
- ret = gntdev_get_page(batch, virt, true, &gfn);
+ ret = gntdev_get_page(batch, virt, &gfn);
if (ret < 0)
return ret;
--
2.26.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 4.19 bp] xen/gntdev.c: Mark pages as dirty
2021-01-01 17:25 ` [PATCH 4.19 bp] xen/gntdev.c: Mark pages as dirty Jinoh Kang
@ 2021-01-04 10:25 ` Greg Kroah-Hartman
0 siblings, 0 replies; 3+ messages in thread
From: Greg Kroah-Hartman @ 2021-01-04 10:25 UTC (permalink / raw)
To: Jinoh Kang
Cc: Souptick Joarder, Boris Ostrovsky, David Vrabel, Juergen Gross,
John Hubbard, stable
On Fri, Jan 01, 2021 at 05:25:50PM +0000, Jinoh Kang wrote:
> From: Souptick Joarder <jrdr.linux@gmail.com>
>
> commit 779055842da5b2e508f3ccf9a8153cb1f704f566 upstream.
Thanks for the backport, now queued up.
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-01-04 10:24 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-10-31 10:03 FAILED: patch "[PATCH] xen/gntdev.c: Mark pages as dirty" failed to apply to 4.19-stable tree gregkh
2021-01-01 17:25 ` [PATCH 4.19 bp] xen/gntdev.c: Mark pages as dirty Jinoh Kang
2021-01-04 10:25 ` Greg Kroah-Hartman
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