[PATCH v2 2/4] staging: kpc2000: kpc_dma: Convert set_page_dirty() --> set_page_dirty_lock()

From: Souptick Joarder
Date: Tue Jun 30 2020 - 03:44:28 EST


First, convert set_page_dirty() to set_page_dirty_lock()

Second, there is an interval in there after set_page_dirty() and
before put_page(), in which the device could be running and setting
pages dirty. Moving set_page_dirty_lock() after dma_unmap_sg().

Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
Suggested-by: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Bharath Vedartham <linux.bhar@xxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/staging/kpc2000/kpc_dma/fileops.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/kpc2000/kpc_dma/fileops.c b/drivers/staging/kpc2000/kpc_dma/fileops.c
index becdb41..08d90a6 100644
--- a/drivers/staging/kpc2000/kpc_dma/fileops.c
+++ b/drivers/staging/kpc2000/kpc_dma/fileops.c
@@ -215,13 +215,13 @@ void transfer_complete_cb(struct aio_cb_data *acd, size_t xfr_count, u32 flags)
BUG_ON(!acd->ldev);
BUG_ON(!acd->ldev->pldev);

+ dma_unmap_sg(&acd->ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, acd->ldev->dir);
+
for (i = 0 ; i < acd->page_count ; i++) {
if (!PageReserved(acd->user_pages[i]))
- set_page_dirty(acd->user_pages[i]);
+ set_page_dirty_lock(acd->user_pages[i]);
}

- dma_unmap_sg(&acd->ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, acd->ldev->dir);
-
for (i = 0 ; i < acd->page_count ; i++)
put_page(acd->user_pages[i]);

--
1.9.1