Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszer...

[cascardo/linux.git] / fs / overlayfs / super.c

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index e38ee0f..a4cbdf9 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -9,6 +9,7 @@
 
 #include <linux/fs.h>
 #include <linux/namei.h>
+#include <linux/pagemap.h>
 #include <linux/xattr.h>
 #include <linux/security.h>
 #include <linux/mount.h>
@@ -24,12 +25,11 @@ MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
 MODULE_DESCRIPTION("Overlay filesystem");
 MODULE_LICENSE("GPL");
 
-#define OVERLAYFS_SUPER_MAGIC 0x794c7630
-
 struct ovl_config {
        char *lowerdir;
        char *upperdir;
        char *workdir;
+       bool default_permissions;
 };
 
 /* private information held for overlayfs's superblock */
@@ -154,6 +154,18 @@ struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper)
        return realdentry;
 }
 
+struct vfsmount *ovl_entry_mnt_real(struct ovl_entry *oe, struct inode *inode,
+                                   bool is_upper)
+{
+       if (is_upper) {
+               struct ovl_fs *ofs = inode->i_sb->s_fs_info;
+
+               return ofs->upper_mnt;
+       } else {
+               return oe->numlower ? oe->lowerstack[0].mnt : NULL;
+       }
+}
+
 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry)
 {
        struct ovl_entry *oe = dentry->d_fsdata;
@@ -161,6 +173,13 @@ struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry)
        return oe->cache;
 }
 
+bool ovl_is_default_permissions(struct inode *inode)
+{
+       struct ovl_fs *ofs = inode->i_sb->s_fs_info;
+
+       return ofs->config.default_permissions;
+}
+
 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache)
 {
        struct ovl_entry *oe = dentry->d_fsdata;
@@ -594,6 +613,8 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
                seq_show_option(m, "upperdir", ufs->config.upperdir);
                seq_show_option(m, "workdir", ufs->config.workdir);
        }
+       if (ufs->config.default_permissions)
+               seq_puts(m, ",default_permissions");
        return 0;
 }
 
@@ -618,6 +639,7 @@ enum {
        OPT_LOWERDIR,
        OPT_UPPERDIR,
        OPT_WORKDIR,
+       OPT_DEFAULT_PERMISSIONS,
        OPT_ERR,
 };
 
@@ -625,6 +647,7 @@ static const match_table_t ovl_tokens = {
        {OPT_LOWERDIR,                  "lowerdir=%s"},
        {OPT_UPPERDIR,                  "upperdir=%s"},
        {OPT_WORKDIR,                   "workdir=%s"},
+       {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
        {OPT_ERR,                       NULL}
 };
 
@@ -685,6 +708,10 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
                                return -ENOMEM;
                        break;
 
+               case OPT_DEFAULT_PERMISSIONS:
+                       config->default_permissions = true;
+                       break;
+
                default:
                        pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p);
                        return -EINVAL;
@@ -910,6 +937,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
        }
 
        sb->s_stack_depth = 0;
+       sb->s_maxbytes = MAX_LFS_FILESIZE;
        if (ufs->config.upperdir) {
                if (!ufs->config.workdir) {
                        pr_err("overlayfs: missing 'workdir'\n");
@@ -1053,6 +1081,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 
        root_dentry->d_fsdata = oe;
 
+       ovl_copyattr(ovl_dentry_real(root_dentry)->d_inode,
+                    root_dentry->d_inode);
+
        sb->s_magic = OVERLAYFS_SUPER_MAGIC;
        sb->s_op = &ovl_super_operations;
        sb->s_root = root_dentry;