1 files changed, 26 insertions, 70 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index b35195289945..3a5b4e923455 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -35,7 +35,7 @@
 
 static struct super_operations hugetlbfs_ops;
 static struct address_space_operations hugetlbfs_aops;
-struct file_operations hugetlbfs_file_operations;
+const struct file_operations hugetlbfs_file_operations;
 static struct inode_operations hugetlbfs_dir_inode_operations;
 static struct inode_operations hugetlbfs_inode_operations;
 
@@ -56,48 +56,10 @@ static void huge_pagevec_release(struct pagevec *pvec)
         pagevec_reinit(pvec);
 }
 
-/*
- * huge_pages_needed tries to determine the number of new huge pages that
- * will be required to fully populate this VMA.  This will be equal to
- * the size of the VMA in huge pages minus the number of huge pages
- * (covered by this VMA) that are found in the page cache.
- *
- * Result is in bytes to be compatible with is_hugepage_mem_enough()
- */
-static unsigned long
-huge_pages_needed(struct address_space *mapping, struct vm_area_struct *vma)
-{
-        int i;
-        struct pagevec pvec;
-        unsigned long start = vma->vm_start;
-        unsigned long end = vma->vm_end;
-        unsigned long hugepages = (end - start) >> HPAGE_SHIFT;
-        pgoff_t next = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT);
-        pgoff_t endpg = next + hugepages;
-
-        pagevec_init(&pvec, 0);
-        while (next < endpg) {
-                if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE))
-                        break;
-                for (i = 0; i < pagevec_count(&pvec); i++) {
-                        struct page *page = pvec.pages[i];
-                        if (page->index > next)
-                                next = page->index;
-                        if (page->index >= endpg)
-                                break;
-                        next++;
-                        hugepages--;
-                }
-                huge_pagevec_release(&pvec);
-        }
-        return hugepages << HPAGE_SHIFT;
-}
-
 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
         struct inode *inode = file->f_dentry->d_inode;
-        struct address_space *mapping = inode->i_mapping;
-        unsigned long bytes;
+        struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
         loff_t len, vma_len;
         int ret;
 
@@ -113,10 +75,6 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
         if (vma->vm_end - vma->vm_start < HPAGE_SIZE)
                 return -EINVAL;
 
-        bytes = huge_pages_needed(mapping, vma);
-        if (!is_hugepage_mem_enough(bytes))
-                return -ENOMEM;
-
         vma_len = (loff_t)(vma->vm_end - vma->vm_start);
 
         mutex_lock(&inode->i_mutex);
@@ -129,6 +87,10 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
         if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size)
                 goto out;
 
+        if (vma->vm_flags & VM_MAYSHARE)
+                if (hugetlb_extend_reservation(info, len >> HPAGE_SHIFT) != 0)
+                        goto out;
+
         ret = 0;
         hugetlb_prefault_arch_hook(vma->vm_mm);
         if (inode->i_size < len)
@@ -227,13 +189,18 @@ static void truncate_huge_page(struct page *page)
         put_page(page);
 }
 
-static void truncate_hugepages(struct address_space *mapping, loff_t lstart)
+static void truncate_hugepages(struct inode *inode, loff_t lstart)
 {
+        struct address_space *mapping = &inode->i_data;
         const pgoff_t start = lstart >> HPAGE_SHIFT;
         struct pagevec pvec;
         pgoff_t next;
         int i;
 
+        hugetlb_truncate_reservation(HUGETLBFS_I(inode),
+                                     lstart >> HPAGE_SHIFT);
+        if (!mapping->nrpages)
+                return;
         pagevec_init(&pvec, 0);
         next = start;
         while (1) {
@@ -262,8 +229,7 @@ static void truncate_hugepages(struct address_space *mapping, loff_t lstart)
 
 static void hugetlbfs_delete_inode(struct inode *inode)
 {
-        if (inode->i_data.nrpages)
-                truncate_hugepages(&inode->i_data, 0);
+        truncate_hugepages(inode, 0);
         clear_inode(inode);
 }
 
@@ -296,8 +262,7 @@ static void hugetlbfs_forget_inode(struct inode *inode)
         inode->i_state |= I_FREEING;
         inodes_stat.nr_inodes--;
         spin_unlock(&inode_lock);
-        if (inode->i_data.nrpages)
-                truncate_hugepages(&inode->i_data, 0);
+        truncate_hugepages(inode, 0);
         clear_inode(inode);
         destroy_inode(inode);
 }
@@ -356,7 +321,7 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
         if (!prio_tree_empty(&mapping->i_mmap))
                 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
         spin_unlock(&mapping->i_mmap_lock);
-        truncate_hugepages(mapping, offset);
+        truncate_hugepages(inode, offset);
         return 0;
 }
 
@@ -573,6 +538,7 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
                 hugetlbfs_inc_free_inodes(sbinfo);
                 return NULL;
         }
+        p->prereserved_hpages = 0;
         return &p->vfs_inode;
 }
 
@@ -600,7 +566,7 @@ static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
                 inode_init_once(&ei->vfs_inode);
 }
 
-struct file_operations hugetlbfs_file_operations = {
+const struct file_operations hugetlbfs_file_operations = {
         .mmap                   = hugetlbfs_file_mmap,
         .fsync                  = simple_sync_file,
         .get_unmapped_area      = hugetlb_get_unmapped_area,
@@ -771,21 +737,6 @@ static struct file_system_type hugetlbfs_fs_type = {
 
 static struct vfsmount *hugetlbfs_vfsmount;
 
-/*
- * Return the next identifier for a shm file
- */
-static unsigned long hugetlbfs_counter(void)
-{
-        static DEFINE_SPINLOCK(lock);
-        static unsigned long counter;
-        unsigned long ret;
-
-        spin_lock(&lock);
-        ret = ++counter;
-        spin_unlock(&lock);
-        return ret;
-}
-
 static int can_do_hugetlb_shm(void)
 {
         return likely(capable(CAP_IPC_LOCK) ||
@@ -801,18 +752,16 @@ struct file *hugetlb_zero_setup(size_t size)
         struct dentry *dentry, *root;
         struct qstr quick_string;
         char buf[16];
+        static atomic_t counter;
 
         if (!can_do_hugetlb_shm())
                 return ERR_PTR(-EPERM);
 
-        if (!is_hugepage_mem_enough(size))
-                return ERR_PTR(-ENOMEM);
-
         if (!user_shm_lock(size, current->user))
                 return ERR_PTR(-ENOMEM);
 
         root = hugetlbfs_vfsmount->mnt_root;
-        snprintf(buf, 16, "%lu", hugetlbfs_counter());
+        snprintf(buf, 16, "%u", atomic_inc_return(&counter));
         quick_string.name = buf;
         quick_string.len = strlen(quick_string.name);
         quick_string.hash = 0;
@@ -831,6 +780,11 @@ struct file *hugetlb_zero_setup(size_t size)
         if (!inode)
                 goto out_file;
 
+        error = -ENOMEM;
+        if (hugetlb_extend_reservation(HUGETLBFS_I(inode),
+                                       size >> HPAGE_SHIFT) != 0)
+                goto out_inode;
+
         d_instantiate(dentry, inode);
         inode->i_size = size;
         inode->i_nlink = 0;
@@ -841,6 +795,8 @@ struct file *hugetlb_zero_setup(size_t size)
         file->f_mode = FMODE_WRITE | FMODE_READ;
         return file;
 
+out_inode:
+        iput(inode);
 out_file:
         put_filp(file);
 out_dentry: