mm: mempolicy: Hide MPOL_NOOP and MPOL_MF_LAZY from userspace for now

The use of MPOL_NOOP and MPOL_MF_LAZY to allow an application to
explicitly request lazy migration is a good idea but the actual
API has not been well reviewed and once released we have to support it.
For now this patch prevents an application using the services. This
will need to be revisited.

Signed-off-by: Mel Gorman <mgorman@suse.de>

1 files changed, 4 insertions, 5 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 75d4600a5e92..a7a62fe7c280 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -252,7 +252,7 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
         pr_debug("setting mode %d flags %d nodes[0] %lx\n",
                  mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
 
-        if (mode == MPOL_DEFAULT || mode == MPOL_NOOP) {
+        if (mode == MPOL_DEFAULT) {
                 if (nodes && !nodes_empty(*nodes))
                         return ERR_PTR(-EINVAL);
                 return NULL;
@@ -1186,7 +1186,7 @@ static long do_mbind(unsigned long start, unsigned long len,
         if (start & ~PAGE_MASK)
                 return -EINVAL;
 
-        if (mode == MPOL_DEFAULT || mode == MPOL_NOOP)
+        if (mode == MPOL_DEFAULT)
                 flags &= ~MPOL_MF_STRICT;
 
         len = (len + PAGE_SIZE - 1) & PAGE_MASK;
@@ -1241,7 +1241,7 @@ static long do_mbind(unsigned long start, unsigned long len,
                           flags | MPOL_MF_INVERT, &pagelist);
 
         err = PTR_ERR(vma);     /* maybe ... */
-        if (!IS_ERR(vma) && mode != MPOL_NOOP)
+        if (!IS_ERR(vma))
                 err = mbind_range(mm, start, end, new);
 
         if (!err) {
@@ -2530,7 +2530,6 @@ static const char * const policy_modes[] =
         [MPOL_BIND]       = "bind",
         [MPOL_INTERLEAVE] = "interleave",
         [MPOL_LOCAL]      = "local",
-        [MPOL_NOOP]       = "noop",     /* should not actually be used */
 };
 
 
@@ -2581,7 +2580,7 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
                         break;
                 }
         }
-        if (mode >= MPOL_MAX || mode == MPOL_NOOP)
+        if (mode >= MPOL_MAX)
                 goto out;
 
         switch (mode) {