4 files changed, 51 insertions, 33 deletions

diff --git a/mm/fremap.c b/mm/fremap.c
index 736ba7f3306a..b6ec85abbb39 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -198,7 +198,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
                         flags &= MAP_NONBLOCK;
                         get_file(file);
                         addr = mmap_region(file, start, size,
-                                        flags, vma->vm_flags, pgoff, 1);
+                                        flags, vma->vm_flags, pgoff);
                         fput(file);
                         if (IS_ERR_VALUE(addr)) {
                                 err = addr;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 618e98304080..207464209546 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2269,14 +2269,12 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
 
 int hugetlb_reserve_pages(struct inode *inode,
                                         long from, long to,
-                                        struct vm_area_struct *vma)
+                                        struct vm_area_struct *vma,
+                                        int acctflag)
 {
-        long ret, chg;
+        long ret = 0, chg;
         struct hstate *h = hstate_inode(inode);
 
-        if (vma && vma->vm_flags & VM_NORESERVE)
-                return 0;
-
         /*
          * Shared mappings base their reservation on the number of pages that
          * are already allocated on behalf of the file. Private mappings need
@@ -2285,22 +2283,25 @@ int hugetlb_reserve_pages(struct inode *inode,
          */
         if (!vma || vma->vm_flags & VM_SHARED)
                 chg = region_chg(&inode->i_mapping->private_list, from, to);
-        else {
-                struct resv_map *resv_map = resv_map_alloc();
-                if (!resv_map)
-                        return -ENOMEM;
-
+        else
                 chg = to - from;
 
-                set_vma_resv_map(vma, resv_map);
-                set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
-        }
-
         if (chg < 0)
                 return chg;
 
         if (hugetlb_get_quota(inode->i_mapping, chg))
                 return -ENOSPC;
+
+        /*
+         * Only apply hugepage reservation if asked. We still have to
+         * take the filesystem quota because it is an upper limit
+         * defined for the mount and not necessarily memory as a whole
+         */
+        if (acctflag & VM_NORESERVE) {
+                reset_vma_resv_huge_pages(vma);
+                return 0;
+        }
+
         ret = hugetlb_acct_memory(h, chg);
         if (ret < 0) {
                 hugetlb_put_quota(inode->i_mapping, chg);
@@ -2308,6 +2309,16 @@ int hugetlb_reserve_pages(struct inode *inode,
         }
         if (!vma || vma->vm_flags & VM_SHARED)
                 region_add(&inode->i_mapping->private_list, from, to);
+        else {
+                struct resv_map *resv_map = resv_map_alloc();
+
+                if (!resv_map)
+                        return -ENOMEM;
+
+                set_vma_resv_map(vma, resv_map);
+                set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
+        }
+
         return 0;
 }
 
diff --git a/mm/mmap.c b/mm/mmap.c
index 214b6a258eeb..eb1270bebe67 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -918,7 +918,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
         struct inode *inode;
         unsigned int vm_flags;
         int error;
-        int accountable = 1;
         unsigned long reqprot = prot;
 
         /*
@@ -1019,8 +1018,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
                                         return -EPERM;
                                 vm_flags &= ~VM_MAYEXEC;
                         }
-                        if (is_file_hugepages(file))
-                                accountable = 0;
 
                         if (!file->f_op || !file->f_op->mmap)
                                 return -ENODEV;
@@ -1053,8 +1050,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
         if (error)
                 return error;
 
-        return mmap_region(file, addr, len, flags, vm_flags, pgoff,
-                           accountable);
+        return mmap_region(file, addr, len, flags, vm_flags, pgoff);
 }
 EXPORT_SYMBOL(do_mmap_pgoff);
 
@@ -1092,17 +1088,23 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
 
 /*
  * We account for memory if it's a private writeable mapping,
- * and VM_NORESERVE wasn't set.
+ * not hugepages and VM_NORESERVE wasn't set.
  */
-static inline int accountable_mapping(unsigned int vm_flags)
+static inline int accountable_mapping(struct file *file, unsigned int vm_flags)
 {
+        /*
+         * hugetlb has its own accounting separate from the core VM
+         * VM_HUGETLB may not be set yet so we cannot check for that flag.
+         */
+        if (file && is_file_hugepages(file))
+                return 0;
+
         return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE;
 }
 
 unsigned long mmap_region(struct file *file, unsigned long addr,
                           unsigned long len, unsigned long flags,
-                          unsigned int vm_flags, unsigned long pgoff,
-                          int accountable)
+                          unsigned int vm_flags, unsigned long pgoff)
 {
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma, *prev;
@@ -1128,18 +1130,22 @@ munmap_back:
 
         /*
          * Set 'VM_NORESERVE' if we should not account for the
-         * memory use of this mapping. We only honor MAP_NORESERVE
-         * if we're allowed to overcommit memory.
+         * memory use of this mapping.
          */
-        if ((flags & MAP_NORESERVE) && sysctl_overcommit_memory != OVERCOMMIT_NEVER)
-                vm_flags |= VM_NORESERVE;
-        if (!accountable)
-                vm_flags |= VM_NORESERVE;
+        if ((flags & MAP_NORESERVE)) {
+                /* We honor MAP_NORESERVE if allowed to overcommit */
+                if (sysctl_overcommit_memory != OVERCOMMIT_NEVER)
+                        vm_flags |= VM_NORESERVE;
+
+                /* hugetlb applies strict overcommit unless MAP_NORESERVE */
+                if (file && is_file_hugepages(file))
+                        vm_flags |= VM_NORESERVE;
+        }
 
         /*
          * Private writable mapping: check memory availability
          */
-        if (accountable_mapping(vm_flags)) {
+        if (accountable_mapping(file, vm_flags)) {
                 charged = len >> PAGE_SHIFT;
                 if (security_vm_enough_memory(charged))
                         return -ENOMEM;
diff --git a/mm/mprotect.c b/mm/mprotect.c
index abe2694e13f4..258197b76fb4 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -151,10 +151,11 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
         /*
          * If we make a private mapping writable we increase our commit;
          * but (without finer accounting) cannot reduce our commit if we
-         * make it unwritable again.
+         * make it unwritable again. hugetlb mapping were accounted for
+         * even if read-only so there is no need to account for them here
          */
         if (newflags & VM_WRITE) {
-                if (!(oldflags & (VM_ACCOUNT|VM_WRITE|
+                if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB|
                                                 VM_SHARED|VM_NORESERVE))) {
                         charged = nrpages;
                         if (security_vm_enough_memory(charged))