Re: [PATCH 1/1] net/rds: Track user mapped pages through special API

[santosh . shilimkar]

On 2/11/20 7:03 PM, John Hubbard wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
>
> Convert net/rds to use the newly introduces pin_user_pages() API,
> which properly sets FOLL_PIN. Setting FOLL_PIN is now required for
> code that requires tracking of pinned pages.
>
> Note that this effectively changes the code's behavior: it now
> ultimately calls 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]
>
> [1] https://urldefense.com/v3/__https://lore.kernel.org/r/20190723153640.GB720@xxxxxxxx;!!GqivPVa7Brio!OJHuecs9Iup5ig3kQBi_423uMMuskWhBQAdOICrY3UQ_ZfEaxt9ySY7E8y32Q7pk5tByyA$
>
> Cc: Hans Westgaard Ry <hans.westgaard.ry@xxxxxxxxxx>
> Cc: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
> ---
Change looks fine to me. Just on safer side, we will try
to test this change with regression suite to make sure it
works as expected.

For patch itself,

Acked-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>