On Fri, 11 Feb 2011 12:48:56 -0600
shirishpargaonkar@xxxxxxxxx wrote:
> From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
>
>
> Define (global) data structures to store ids, uids and gids, to which a
> SID maps. There are two separate trees, one for SID/uid and another one
> for SID/gid.
>
> A new type of key, cifs_idmap_key_type, is used.
>
> Keys are instantiated and searched using credential of the root by
> overriding and restoring the credentials of the caller requesting the key.
> Once a SID is mapped, it is stored along with the mapped id, in one
> of the rb trees and key is released.
>
> Register a pruning function with the shrinker that prunes the rb trees
> when memory pressure warrants freeing up cache. Just for now, it is
> more like cleaning entire cache than pruning. The subsequent patch has
> this function defined.
>
>
> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
> ---
> fs/cifs/cifsacl.c | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++
> fs/cifs/cifsfs.c | 7 +++
> fs/cifs/cifsglob.h | 5 ++
> fs/cifs/cifsproto.h | 3 +
> 4 files changed, 153 insertions(+), 0 deletions(-)
>
> diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
> index beeebf1..388b34c 100644
> --- a/fs/cifs/cifsacl.c
> +++ b/fs/cifs/cifsacl.c
> @@ -23,6 +23,10 @@
>
> #include <linux/fs.h>
> #include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/keyctl.h>
> +#include <linux/key-type.h>
> +#include <keys/user-type.h>
> #include "cifspdu.h"
> #include "cifsglob.h"
> #include "cifsacl.h"
> @@ -50,6 +54,140 @@ static const struct cifs_sid sid_authusers = {
> /* group users */
> static const struct cifs_sid sid_user = {1, 2 , {0, 0, 0, 0, 0, 5}, {} };
>
> +static const struct cred *root_cred;
> +
> +/*
> + * Run idmap cache shrinker.
> + */
> +static int
> +cifs_idmap_shrinker(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
> +{
> + /* Use a pruning scheme in a subsequent patch instead */
^^^^
maybe add the standard "FIXME:" prefix? to the comment above?
> + cifs_destroy_idmaptrees();
> + return 0;
> +}
> +
Aside from the trivial comment fix, this looks OK, I guess. Eventually
it would be good to have a more selective pruning scheme than just
dropping the entire idmap cache.
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-cifs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
