2 files changed, 23 insertions, 2 deletions

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 5e02b83ac12b..ea7d1bdad34d 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -311,6 +311,18 @@ Who:	Vlad Yasevich <vladislav.yasevich@hp.com>
 
 ---------------------------
 
+What:   Ability for non root users to shm_get hugetlb pages based on mlock
+        resource limits
+When:   2.6.31
+Why:    Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
+        have CAP_IPC_LOCK to be able to allocate shm segments backed by
+        huge pages.  The mlock based rlimit check to allow shm hugetlb is
+        inconsistent with mmap based allocations.  Hence it is being
+        deprecated.
+Who:    Ravikiran Thirumalai <kiran@scalex86.org>
+
+---------------------------
+
 What:   CONFIG_THERMAL_HWMON
 When:   January 2009
 Why:    This option was introduced just to allow older lm-sensors userspace
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index bc56df8ce001..23a3c76711e0 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -949,6 +949,7 @@ static int can_do_hugetlb_shm(void)
 struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag)
 {
         int error = -ENOMEM;
+        int unlock_shm = 0;
         struct file *file;
         struct inode *inode;
         struct dentry *dentry, *root;
@@ -958,8 +959,14 @@ struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag)
         if (!hugetlbfs_vfsmount)
                 return ERR_PTR(-ENOENT);
 
-        if (!can_do_hugetlb_shm())
-                return ERR_PTR(-EPERM);
+        if (!can_do_hugetlb_shm()) {
+                if (user_shm_lock(size, user)) {
+                        unlock_shm = 1;
+                        WARN_ONCE(1,
+                          "Using mlock ulimits for SHM_HUGETLB deprecated\n");
+                } else
+                        return ERR_PTR(-EPERM);
+        }
 
         root = hugetlbfs_vfsmount->mnt_root;
         quick_string.name = name;
@@ -999,6 +1006,8 @@ out_inode:
 out_dentry:
         dput(dentry);
 out_shm_unlock:
+        if (unlock_shm)
+                user_shm_unlock(size, user);
         return ERR_PTR(error);
 }