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Commit 4155c10a authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

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: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent bca44b52

fs/overlayfs/super.c

+48 −52
Original line number Diff line number Diff line
@@ -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_dentry_release(struct dentry *dentry)

static void ovl_entry_stack_free(struct ovl_entry *oe)

{

	struct ovl_entry *oe = dentry->d_fsdata;



	if (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) {

		ovl_entry_stack_free(oe);

		kfree_rcu(oe, rcu);

	}

}
@@ -1058,35 +1063,36 @@ static int ovl_get_lower_layers(struct ovl_fs *ufs, struct path *stack, 
	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: