linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / fs / hugetlbfs / inode.c

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 3a5b4e9..b351952 100644 (file)
--- 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;
-const struct file_operations hugetlbfs_file_operations;
+struct file_operations hugetlbfs_file_operations;
 static struct inode_operations hugetlbfs_dir_inode_operations;
 static struct inode_operations hugetlbfs_inode_operations;
 
@@ -56,10 +56,48 @@ 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 hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
+       struct address_space *mapping = inode->i_mapping;
+       unsigned long bytes;
        loff_t len, vma_len;
        int ret;
 
@@ -75,6 +113,10 @@ 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);
@@ -87,10 +129,6 @@ 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)
@@ -189,18 +227,13 @@ static void truncate_huge_page(struct page *page)
        put_page(page);
 }
 
-static void truncate_hugepages(struct inode *inode, loff_t lstart)
+static void truncate_hugepages(struct address_space *mapping, 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) {
@@ -229,7 +262,8 @@ static void truncate_hugepages(struct inode *inode, loff_t lstart)
 
 static void hugetlbfs_delete_inode(struct inode *inode)
 {
-       truncate_hugepages(inode, 0);
+       if (inode->i_data.nrpages)
+               truncate_hugepages(&inode->i_data, 0);
        clear_inode(inode);
 }
 
@@ -262,7 +296,8 @@ static void hugetlbfs_forget_inode(struct inode *inode)
        inode->i_state |= I_FREEING;
        inodes_stat.nr_inodes--;
        spin_unlock(&inode_lock);
-       truncate_hugepages(inode, 0);
+       if (inode->i_data.nrpages)
+               truncate_hugepages(&inode->i_data, 0);
        clear_inode(inode);
        destroy_inode(inode);
 }
@@ -321,7 +356,7 @@ 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(inode, offset);
+       truncate_hugepages(mapping, offset);
        return 0;
 }
 
@@ -538,7 +573,6 @@ 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;
 }
 
@@ -566,7 +600,7 @@ static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
                inode_init_once(&ei->vfs_inode);
 }
 
-const struct file_operations hugetlbfs_file_operations = {
+struct file_operations hugetlbfs_file_operations = {
        .mmap                   = hugetlbfs_file_mmap,
        .fsync                  = simple_sync_file,
        .get_unmapped_area      = hugetlb_get_unmapped_area,
@@ -737,6 +771,21 @@ 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) ||
@@ -752,16 +801,18 @@ 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, "%u", atomic_inc_return(&counter));
+       snprintf(buf, 16, "%lu", hugetlbfs_counter());
        quick_string.name = buf;
        quick_string.len = strlen(quick_string.name);
        quick_string.hash = 0;
@@ -780,11 +831,6 @@ 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;
@@ -795,8 +841,6 @@ 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: