mm: reintroduce and deprecate rlimit based access for SHM_HUGETLB
Allow non root users with sufficient mlock rlimits to be able to allocate
hugetlb backed shm for now. Deprecate this though. This is being
deprecated because the mlock based rlimit checks for SHM_HUGETLB is not
consistent with mmap based huge page allocations.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index bc56df8c..23a3c76 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -949,6 +949,7 @@
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 @@
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_dentry:
dput(dentry);
out_shm_unlock:
+ if (unlock_shm)
+ user_shm_unlock(size, user);
return ERR_PTR(error);
}