On Thu 14-11-19 21:53:27, John Hubbard wrote:
Call the new global pin_user_pages_fast(), from pin_goldfish_pages().
As required by pin_user_pages(), release these pages via
put_user_page(). In this case, do so via put_user_pages_dirty_lock().
That has the side effect of calling set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate.
As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1]
Another side effect is that the release code is simplified because the page[] loop is now in gup.c instead of here, so just delete the local release_user_pages() entirely, and call put_user_pages_dirty_lock() directly, instead.
[1] https://lore.kernel.org/r/20190723153640.GB720@lst.de
Reviewed-by: Ira Weiny ira.weiny@intel.com Signed-off-by: John Hubbard jhubbard@nvidia.com
Looks good to me. You can add:
Reviewed-by: Jan Kara jack@suse.cz
Honza
drivers/platform/goldfish/goldfish_pipe.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c index 7ed2a21a0bac..635a8bc1b480 100644 --- a/drivers/platform/goldfish/goldfish_pipe.c +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -274,7 +274,7 @@ static int pin_goldfish_pages(unsigned long first_page, *iter_last_page_size = last_page_size; }
- ret = get_user_pages_fast(first_page, requested_pages,
- ret = pin_user_pages_fast(first_page, requested_pages, !is_write ? FOLL_WRITE : 0, pages); if (ret <= 0)
@@ -285,18 +285,6 @@ static int pin_goldfish_pages(unsigned long first_page, return ret; } -static void release_user_pages(struct page **pages, int pages_count,
int is_write, s32 consumed_size)-{
- int i;
- for (i = 0; i < pages_count; i++) {
if (!is_write && consumed_size > 0)set_page_dirty(pages[i]);put_page(pages[i]);- }
-}
/* Populate the call parameters, merging adjacent pages together */ static void populate_rw_params(struct page **pages, int pages_count, @@ -372,7 +360,8 @@ static int transfer_max_buffers(struct goldfish_pipe *pipe, *consumed_size = pipe->command_buffer->rw_params.consumed_size;
- release_user_pages(pipe->pages, pages_count, is_write, *consumed_size);
- put_user_pages_dirty_lock(pipe->pages, pages_count,
!is_write && *consumed_size > 0);mutex_unlock(&pipe->lock); return 0; -- 2.24.0