ovl: clean up getting lower layers

Move calling ovl_get_lower_layers() into ovl_get_lowerstack().

ovl_get_lowerstack() now returns the root dentry's filled in ovl_entry.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 115cbf3..e4852cb 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -38,15 +38,20 @@ module_param_named(index, ovl_index_def, bool, 0644);
 MODULE_PARM_DESC(ovl_index_def,
                 "Default to on or off for the inodes index feature");
 
+static void ovl_entry_stack_free(struct ovl_entry *oe)
+{
+       unsigned int i;
+
+       for (i = 0; i < oe->numlower; i++)
+               dput(oe->lowerstack[i].dentry);
+}
+
 static void ovl_dentry_release(struct dentry *dentry)
 {
        struct ovl_entry *oe = dentry->d_fsdata;
 
        if (oe) {
-               unsigned int i;
-
-               for (i = 0; i < oe->numlower; i++)
-                       dput(oe->lowerstack[i].dentry);
+               ovl_entry_stack_free(oe);
                kfree_rcu(oe, rcu);
        }
 }
@@ -1058,35 +1063,36 @@ out:
        return err;
 }
 
-static int ovl_get_lowerstack(struct super_block *sb, struct ovl_fs *ufs,
-                             struct path **stackp, unsigned int *stacklenp)
+static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
+                                           struct ovl_fs *ufs)
 {
        int err;
        char *lowertmp, *lower;
-       struct path *stack;
-       unsigned int stacklen, numlower, i;
+       struct path *stack = NULL;
+       unsigned int stacklen, numlower = 0, i;
        bool remote = false;
+       struct ovl_entry *oe;
 
        err = -ENOMEM;
        lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL);
        if (!lowertmp)
-               goto out;
+               goto out_err;
 
        err = -EINVAL;
        stacklen = ovl_split_lowerdirs(lowertmp);
        if (stacklen > OVL_MAX_STACK) {
                pr_err("overlayfs: too many lower directories, limit is %d\n",
                       OVL_MAX_STACK);
-               goto out;
+               goto out_err;
        } else if (!ufs->config.upperdir && stacklen == 1) {
                pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n");
-               goto out;
+               goto out_err;
        }
 
        err = -ENOMEM;
        stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL);
        if (!stack)
-               goto out;
+               goto out_err;
 
        err = -EINVAL;
        lower = lowertmp;
@@ -1094,7 +1100,7 @@ static int ovl_get_lowerstack(struct super_block *sb, struct ovl_fs *ufs,
                err = ovl_lower_dir(lower, &stack[numlower], ufs,
                                    &sb->s_stack_depth, &remote);
                if (err)
-                       goto out_free_stack;
+                       goto out_err;
 
                lower = strchr(lower, '\0') + 1;
        }
@@ -1103,27 +1109,38 @@ static int ovl_get_lowerstack(struct super_block *sb, struct ovl_fs *ufs,
        sb->s_stack_depth++;
        if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
                pr_err("overlayfs: maximum fs stacking depth exceeded\n");
-               goto out_free_stack;
+               goto out_err;
        }
 
-       *stackp = stack;
-       *stacklenp = numlower;
+       err = ovl_get_lower_layers(ufs, stack, numlower);
+       if (err)
+               goto out_err;
+
+       err = -ENOMEM;
+       oe = ovl_alloc_entry(numlower);
+       if (!oe)
+               goto out_err;
+
+       for (i = 0; i < numlower; i++) {
+               oe->lowerstack[i].dentry = dget(stack[i].dentry);
+               oe->lowerstack[i].layer = &ufs->lower_layers[i];
+       }
 
        if (remote)
                sb->s_d_op = &ovl_reval_dentry_operations;
        else
                sb->s_d_op = &ovl_dentry_operations;
 
-       err = 0;
-
 out:
-       kfree(lowertmp);
-       return err;
-
-out_free_stack:
        for (i = 0; i < numlower; i++)
                path_put(&stack[i]);
        kfree(stack);
+       kfree(lowertmp);
+
+       return oe;
+
+out_err:
+       oe = ERR_PTR(err);
        goto out;
 }
 
@@ -1131,11 +1148,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 {
        struct path upperpath = { };
        struct dentry *root_dentry;
-       struct ovl_entry *oe = NULL;
+       struct ovl_entry *oe;
        struct ovl_fs *ufs;
-       struct path *stack = NULL;
-       unsigned int numlower = 0;
-       unsigned int i;
        struct cred *cred;
        int err;
 
@@ -1184,12 +1198,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
                sb->s_time_gran = ufs->upper_mnt->mnt_sb->s_time_gran;
 
        }
-       err = ovl_get_lowerstack(sb, ufs, &stack, &numlower);
-       if (err)
-               goto out_err;
-
-       err = ovl_get_lower_layers(ufs, stack, numlower);
-       if (err)
+       oe = ovl_get_lowerstack(sb, ufs);
+       err = PTR_ERR(oe);
+       if (IS_ERR(oe))
                goto out_err;
 
        /* If the upper fs is nonexistent, we mark overlayfs r/o too */
@@ -1198,20 +1209,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
        else if (ufs->upper_mnt->mnt_sb != ufs->same_sb)
                ufs->same_sb = NULL;
 
-       err = -ENOMEM;
-       oe = ovl_alloc_entry(numlower);
-       if (!oe)
-               goto out_err;
-
-       for (i = 0; i < numlower; i++) {
-               oe->lowerstack[i].dentry = stack[i].dentry;
-               oe->lowerstack[i].layer = &(ufs->lower_layers[i]);
-       }
-
        if (!(ovl_force_readonly(ufs)) && ufs->config.index) {
                err = ovl_get_indexdir(ufs, oe, &upperpath);
                if (err)
-                       goto out_err;
+                       goto out_free_oe;
 
                if (!ufs->indexdir)
                        sb->s_flags |= MS_RDONLY;
@@ -1233,13 +1234,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
        err = -ENOMEM;
        root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0));
        if (!root_dentry)
-               goto out_err;
+               goto out_free_oe;
 
        mntput(upperpath.mnt);
-       for (i = 0; i < numlower; i++)
-               mntput(stack[i].mnt);
-       kfree(stack);
-
        if (upperpath.dentry) {
                oe->has_upper = true;
                if (ovl_is_impuredir(upperpath.dentry))
@@ -1257,11 +1254,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 
        return 0;
 
-out_err:
+out_free_oe:
+       ovl_entry_stack_free(oe);
        kfree(oe);
-       for (i = 0; i < numlower; i++)
-               path_put(&stack[i]);
-       kfree(stack);
+out_err:
        path_put(&upperpath);
        ovl_free_fs(ufs);
 out: