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Commit 1afaba1e authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

ovl: make path-type a bitmap 



OVL_PATH_PURE_UPPER -> __OVL_PATH_UPPER | __OVL_PATH_PURE
OVL_PATH_UPPER      -> __OVL_PATH_UPPER
OVL_PATH_MERGE      -> __OVL_PATH_UPPER | __OVL_PATH_MERGE
OVL_PATH_LOWER      -> 0

Multiple R/O layers will allow __OVL_PATH_MERGE without __OVL_PATH_UPPER.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
parent 49c21e1c

fs/overlayfs/copy_up.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -385,7 +385,7 @@ int ovl_copy_up(struct dentry *dentry) 
		struct kstat stat;

		struct kstat stat;

		enum ovl_path_type type = ovl_path_type(dentry);

		enum ovl_path_type type = ovl_path_type(dentry);





		if (type != OVL_PATH_LOWER)

		if (OVL_TYPE_UPPER(type))

			break;

			break;





		next = dget(dentry);

		next = dget(dentry);
@@ -394,7 +394,7 @@ int ovl_copy_up(struct dentry *dentry) 
			parent = dget_parent(next);

			parent = dget_parent(next);





			type = ovl_path_type(parent);

			type = ovl_path_type(parent);

			if (type != OVL_PATH_LOWER)

			if (OVL_TYPE_UPPER(type))

				break;

				break;





			dput(next);

			dput(next);

fs/overlayfs/dir.c

+11 −11
Original line number Original line Diff line number Diff line
@@ -152,7 +152,7 @@ static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry, 
	 * correct link count.  nlink=1 seems to pacify 'find' and

	 * correct link count.  nlink=1 seems to pacify 'find' and

	 * other utilities.

	 * other utilities.

	 */

	 */

	if (type == OVL_PATH_MERGE)

	if (OVL_TYPE_MERGE(type))

		stat->nlink = 1;

		stat->nlink = 1;





	return 0;

	return 0;
@@ -630,7 +630,7 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir) 
		goto out_drop_write;

		goto out_drop_write;





	type = ovl_path_type(dentry);

	type = ovl_path_type(dentry);

	if (type == OVL_PATH_PURE_UPPER) {

	if (OVL_TYPE_PURE_UPPER(type)) {

		err = ovl_remove_upper(dentry, is_dir);

		err = ovl_remove_upper(dentry, is_dir);

	} else {

	} else {

		const struct cred *old_cred;

		const struct cred *old_cred;
@@ -712,7 +712,7 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, 
	/* Don't copy up directory trees */

	/* Don't copy up directory trees */

	old_type = ovl_path_type(old);

	old_type = ovl_path_type(old);

	err = -EXDEV;

	err = -EXDEV;

	if ((old_type == OVL_PATH_LOWER || old_type == OVL_PATH_MERGE) && is_dir)

	if (OVL_TYPE_MERGE_OR_LOWER(old_type) && is_dir)

		goto out;

		goto out;





	if (new->d_inode) {

	if (new->d_inode) {
@@ -725,25 +725,25 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, 




		new_type = ovl_path_type(new);

		new_type = ovl_path_type(new);

		err = -EXDEV;

		err = -EXDEV;

		if (!overwrite && (new_type == OVL_PATH_LOWER || new_type == OVL_PATH_MERGE) && new_is_dir)

		if (!overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir)

			goto out;

			goto out;





		err = 0;

		err = 0;

		if (new_type == OVL_PATH_LOWER && old_type == OVL_PATH_LOWER) {

		if (!OVL_TYPE_UPPER(new_type) && !OVL_TYPE_UPPER(old_type)) {

			if (ovl_dentry_lower(old)->d_inode ==

			if (ovl_dentry_lower(old)->d_inode ==

			    ovl_dentry_lower(new)->d_inode)

			    ovl_dentry_lower(new)->d_inode)

				goto out;

				goto out;

		}

		}

		if (new_type != OVL_PATH_LOWER && old_type != OVL_PATH_LOWER) {

		if (OVL_TYPE_UPPER(new_type) && OVL_TYPE_UPPER(old_type)) {

			if (ovl_dentry_upper(old)->d_inode ==

			if (ovl_dentry_upper(old)->d_inode ==

			    ovl_dentry_upper(new)->d_inode)

			    ovl_dentry_upper(new)->d_inode)

				goto out;

				goto out;

		}

		}

	} else {

	} else {

		if (ovl_dentry_is_opaque(new))

		if (ovl_dentry_is_opaque(new))

			new_type = OVL_PATH_UPPER;

			new_type = __OVL_PATH_UPPER;

		else

		else

			new_type = OVL_PATH_PURE_UPPER;

			new_type = __OVL_PATH_UPPER | __OVL_PATH_PURE;

	}

	}





	err = ovl_want_write(old);

	err = ovl_want_write(old);
@@ -763,8 +763,8 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, 
			goto out_drop_write;

			goto out_drop_write;

	}

	}





	old_opaque = old_type != OVL_PATH_PURE_UPPER;

	old_opaque = !OVL_TYPE_PURE_UPPER(old_type);

	new_opaque = new_type != OVL_PATH_PURE_UPPER;

	new_opaque = !OVL_TYPE_PURE_UPPER(new_type);





	if (old_opaque || new_opaque) {

	if (old_opaque || new_opaque) {

		err = -ENOMEM;

		err = -ENOMEM;
@@ -787,7 +787,7 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, 
		old_cred = override_creds(override_cred);

		old_cred = override_creds(override_cred);

	}

	}





	if (overwrite && (new_type == OVL_PATH_LOWER || new_type == OVL_PATH_MERGE) && new_is_dir) {

	if (overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) {

		opaquedir = ovl_check_empty_and_clear(new);

		opaquedir = ovl_check_empty_and_clear(new);

		err = PTR_ERR(opaquedir);

		err = PTR_ERR(opaquedir);

		if (IS_ERR(opaquedir)) {

		if (IS_ERR(opaquedir)) {

fs/overlayfs/inode.c

+6 −3
Original line number Original line Diff line number Diff line
@@ -238,7 +238,10 @@ int ovl_setxattr(struct dentry *dentry, const char *name, 
static bool ovl_need_xattr_filter(struct dentry *dentry,

static bool ovl_need_xattr_filter(struct dentry *dentry,

				  enum ovl_path_type type)

				  enum ovl_path_type type)

{

{

	return type == OVL_PATH_UPPER && S_ISDIR(dentry->d_inode->i_mode);

	if ((type & (__OVL_PATH_PURE | __OVL_PATH_UPPER)) == __OVL_PATH_UPPER)

		return S_ISDIR(dentry->d_inode->i_mode);

	else

		return false;

}

}





ssize_t ovl_getxattr(struct dentry *dentry, const char *name,

ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
@@ -299,7 +302,7 @@ int ovl_removexattr(struct dentry *dentry, const char *name) 
	if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))

	if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))

		goto out_drop_write;

		goto out_drop_write;





	if (type == OVL_PATH_LOWER) {

	if (!OVL_TYPE_UPPER(type)) {

		err = vfs_getxattr(realpath.dentry, name, NULL, 0);

		err = vfs_getxattr(realpath.dentry, name, NULL, 0);

		if (err < 0)

		if (err < 0)

			goto out_drop_write;

			goto out_drop_write;
@@ -321,7 +324,7 @@ int ovl_removexattr(struct dentry *dentry, const char *name) 
static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,

static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,

				  struct dentry *realdentry)

				  struct dentry *realdentry)

{

{

	if (type != OVL_PATH_LOWER)

	if (OVL_TYPE_UPPER(type))

		return false;

		return false;





	if (special_file(realdentry->d_inode->i_mode))

	if (special_file(realdentry->d_inode->i_mode))

fs/overlayfs/overlayfs.h

+9 −4
Original line number Original line Diff line number Diff line
@@ -12,12 +12,17 @@ 
struct ovl_entry;

struct ovl_entry;





enum ovl_path_type {

enum ovl_path_type {

	OVL_PATH_PURE_UPPER,

	__OVL_PATH_PURE		= (1 << 0),

	OVL_PATH_UPPER,

	__OVL_PATH_UPPER	= (1 << 1),

	OVL_PATH_MERGE,

	__OVL_PATH_MERGE	= (1 << 2),

	OVL_PATH_LOWER,

};

};





#define OVL_TYPE_UPPER(type)	((type) & __OVL_PATH_UPPER)

#define OVL_TYPE_MERGE(type)	((type) & __OVL_PATH_MERGE)

#define OVL_TYPE_PURE_UPPER(type) ((type) & __OVL_PATH_PURE)

#define OVL_TYPE_MERGE_OR_LOWER(type) \

	(OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type))



extern const char *ovl_opaque_xattr;

extern const char *ovl_opaque_xattr;





static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)

static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)

fs/overlayfs/readdir.c

+5 −5
Original line number Original line Diff line number Diff line
@@ -253,8 +253,8 @@ static void ovl_dir_reset(struct file *file) 
		ovl_cache_put(od, dentry);

		ovl_cache_put(od, dentry);

		od->cache = NULL;

		od->cache = NULL;

	}

	}

	WARN_ON(!od->is_real && type != OVL_PATH_MERGE);

	WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type));

	if (od->is_real && type == OVL_PATH_MERGE)

	if (od->is_real && OVL_TYPE_MERGE(type))

		od->is_real = false;

		od->is_real = false;

}

}
@@ -429,7 +429,7 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end, 
	/*

	/*

	 * Need to check if we started out being a lower dir, but got copied up

	 * Need to check if we started out being a lower dir, but got copied up

	 */

	 */

	if (!od->is_upper && ovl_path_type(dentry) != OVL_PATH_LOWER) {

	if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) {

		struct inode *inode = file_inode(file);

		struct inode *inode = file_inode(file);





		realfile = lockless_dereference(od->upperfile);

		realfile = lockless_dereference(od->upperfile);
@@ -495,8 +495,8 @@ static int ovl_dir_open(struct inode *inode, struct file *file) 
	}

	}

	INIT_LIST_HEAD(&od->cursor.l_node);

	INIT_LIST_HEAD(&od->cursor.l_node);

	od->realfile = realfile;

	od->realfile = realfile;

	od->is_real = (type != OVL_PATH_MERGE);

	od->is_real = !OVL_TYPE_MERGE(type);

	od->is_upper = (type != OVL_PATH_LOWER);

	od->is_upper = OVL_TYPE_UPPER(type);

	od->cursor.is_cursor = true;

	od->cursor.is_cursor = true;

	file->private_data = od;

	file->private_data = od;