1 files changed, 74 insertions, 21 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index eef4ebea5158..855eaf5b8d5b 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -433,8 +433,6 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long
 
                 spin_unlock(&info->lock);
                 page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping));
-                if (page)
-                        set_page_private(page, 0);
                 spin_lock(&info->lock);
 
                 if (!page) {
@@ -1545,8 +1543,8 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma)
         return 0;
 }
 
-static struct inode *shmem_get_inode(struct super_block *sb, int mode,
-                                        dev_t dev, unsigned long flags)
+static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir,
+                                     int mode, dev_t dev, unsigned long flags)
 {
         struct inode *inode;
         struct shmem_inode_info *info;
@@ -1557,9 +1555,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, int mode,
 
         inode = new_inode(sb);
         if (inode) {
-                inode->i_mode = mode;
-                inode->i_uid = current_fsuid();
-                inode->i_gid = current_fsgid();
+                inode_init_owner(inode, dir, mode);
                 inode->i_blocks = 0;
                 inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
@@ -1814,7 +1810,7 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
         struct inode *inode;
         int error = -ENOSPC;
 
-        inode = shmem_get_inode(dir->i_sb, mode, dev, VM_NORESERVE);
+        inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
         if (inode) {
                 error = security_inode_init_security(inode, dir, NULL, NULL,
                                                      NULL);
@@ -1833,11 +1829,6 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 #else
                 error = 0;
 #endif
-                if (dir->i_mode & S_ISGID) {
-                        inode->i_gid = dir->i_gid;
-                        if (S_ISDIR(mode))
-                                inode->i_mode |= S_ISGID;
-                }
                 dir->i_size += BOGO_DIRENT_SIZE;
                 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
                 d_instantiate(dentry, inode);
@@ -1957,7 +1948,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
         if (len > PAGE_CACHE_SIZE)
                 return -ENAMETOOLONG;
 
-        inode = shmem_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
+        inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
         if (!inode)
                 return -ENOSPC;
 
@@ -1992,8 +1983,6 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
                 unlock_page(page);
                 page_cache_release(page);
         }
-        if (dir->i_mode & S_ISGID)
-                inode->i_gid = dir->i_gid;
         dir->i_size += BOGO_DIRENT_SIZE;
         dir->i_ctime = dir->i_mtime = CURRENT_TIME;
         d_instantiate(dentry, inode);
@@ -2071,14 +2060,14 @@ static int shmem_xattr_security_set(struct dentry *dentry, const char *name,
                                           size, flags);
 }
 
-static struct xattr_handler shmem_xattr_security_handler = {
+static const struct xattr_handler shmem_xattr_security_handler = {
         .prefix = XATTR_SECURITY_PREFIX,
         .list   = shmem_xattr_security_list,
         .get    = shmem_xattr_security_get,
         .set    = shmem_xattr_security_set,
 };
 
-static struct xattr_handler *shmem_xattr_handlers[] = {
+static const struct xattr_handler *shmem_xattr_handlers[] = {
         &generic_acl_access_handler,
         &generic_acl_default_handler,
         &shmem_xattr_security_handler,
@@ -2366,7 +2355,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
         sb->s_flags |= MS_POSIXACL;
 #endif
 
-        inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
+        inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
         if (!inode)
                 goto failed;
         inode->i_uid = sbinfo->uid;
@@ -2570,6 +2559,45 @@ out4:
         return error;
 }
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
+ * @inode: the inode to be searched
+ * @pgoff: the offset to be searched
+ * @pagep: the pointer for the found page to be stored
+ * @ent: the pointer for the found swap entry to be stored
+ *
+ * If a page is found, refcount of it is incremented. Callers should handle
+ * these refcount.
+ */
+void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
+                                        struct page **pagep, swp_entry_t *ent)
+{
+        swp_entry_t entry = { .val = 0 }, *ptr;
+        struct page *page = NULL;
+        struct shmem_inode_info *info = SHMEM_I(inode);
+
+        if ((pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+                goto out;
+
+        spin_lock(&info->lock);
+        ptr = shmem_swp_entry(info, pgoff, NULL);
+#ifdef CONFIG_SWAP
+        if (ptr && ptr->val) {
+                entry.val = ptr->val;
+                page = find_get_page(&swapper_space, entry.val);
+        } else
+#endif
+                page = find_get_page(inode->i_mapping, pgoff);
+        if (ptr)
+                shmem_swp_unmap(ptr);
+        spin_unlock(&info->lock);
+out:
+        *pagep = page;
+        *ent = entry;
+}
+#endif
+
 #else /* !CONFIG_SHMEM */
 
 /*
@@ -2609,9 +2637,34 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user)
         return 0;
 }
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
+ * @inode: the inode to be searched
+ * @pgoff: the offset to be searched
+ * @pagep: the pointer for the found page to be stored
+ * @ent: the pointer for the found swap entry to be stored
+ *
+ * If a page is found, refcount of it is incremented. Callers should handle
+ * these refcount.
+ */
+void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
+                                        struct page **pagep, swp_entry_t *ent)
+{
+        struct page *page = NULL;
+
+        if ((pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+                goto out;
+        page = find_get_page(inode->i_mapping, pgoff);
+out:
+        *pagep = page;
+        *ent = (swp_entry_t){ .val = 0 };
+}
+#endif
+
 #define shmem_vm_ops                            generic_file_vm_ops
 #define shmem_file_operations                   ramfs_file_operations
-#define shmem_get_inode(sb, mode, dev, flags)   ramfs_get_inode(sb, mode, dev)
+#define shmem_get_inode(sb, dir, mode, dev, flags)      ramfs_get_inode(sb, dir, mode, dev)
 #define shmem_acct_size(flags, size)            0
 #define shmem_unacct_size(flags, size)          do {} while (0)
 #define SHMEM_MAX_BYTES                         MAX_LFS_FILESIZE
@@ -2655,7 +2708,7 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
         path.mnt = mntget(shm_mnt);
 
         error = -ENOSPC;
-        inode = shmem_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0, flags);
+        inode = shmem_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0, flags);
         if (!inode)
                 goto put_dentry;