Commit d602fb68 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull overlayfs fixes from Miklos Szeredi:
 "Fix regressions:

   - missing CONFIG_EXPORTFS dependency

   - failure if upper fs doesn't support xattr

   - bad error cleanup

  This also adds the concept of "impure" directories complementing the
  "origin" marking introduced in -rc1. Together they enable getting
  consistent st_ino and d_ino for directory listings.

  And there's a bug fix and a cleanup as well"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: filter trusted xattr for non-admin
  ovl: mark upper merge dir with type origin entries "impure"
  ovl: mark upper dir with type origin entries "impure"
  ovl: remove unused arg from ovl_lookup_temp()
  ovl: handle rename when upper doesn't support xattr
  ovl: don't fail copy-up if upper doesn't support xattr
  ovl: check on mount time if upper fs supports setting xattr
  ovl: fix creds leak in copy up error path
  ovl: select EXPORTFS
parents f511c0b1 a082c6f6

fs/overlayfs/Kconfig

+1 −0
Original line number Diff line number Diff line 
config OVERLAY_FS

	tristate "Overlay filesystem support"

	select EXPORTFS

	help

	  An overlay filesystem combines two filesystems - an 'upper' filesystem

	  and a 'lower' filesystem.  When a name exists in both filesystems, the

fs/overlayfs/copy_up.c

+17 −7
Original line number Diff line number Diff line
@@ -300,7 +300,11 @@ static int ovl_set_origin(struct dentry *dentry, struct dentry *lower, 
			return PTR_ERR(fh);

	}



	err = ovl_do_setxattr(upper, OVL_XATTR_ORIGIN, fh, fh ? fh->len : 0, 0);

	/*

	 * Do not fail when upper doesn't support xattrs.

	 */

	err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh,

				 fh ? fh->len : 0, 0);

	kfree(fh);



	return err;
@@ -342,13 +346,14 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, 
	if (tmpfile)

		temp = ovl_do_tmpfile(upperdir, stat->mode);

	else

		temp = ovl_lookup_temp(workdir, dentry);

		temp = ovl_lookup_temp(workdir);

	err = 0;

	if (IS_ERR(temp)) {

		err = PTR_ERR(temp);

	if (IS_ERR(temp))

		goto out1;

		temp = NULL;

	}



	err = 0;

	if (!tmpfile)

	if (!err && !tmpfile)

		err = ovl_create_real(wdir, temp, &cattr, NULL, true);



	if (new_creds) {
@@ -454,6 +459,11 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, 
	ovl_path_upper(parent, &parentpath);

	upperdir = parentpath.dentry;



	/* Mark parent "impure" because it may now contain non-pure upper */

	err = ovl_set_impure(parent, upperdir);

	if (err)

		return err;



	err = vfs_getattr(&parentpath, &pstat,

			  STATX_ATIME | STATX_MTIME, AT_STATX_SYNC_AS_STAT);

	if (err)

fs/overlayfs/dir.c

+47 −14
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ void ovl_cleanup(struct inode *wdir, struct dentry *wdentry) 
	}

}



struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry)

struct dentry *ovl_lookup_temp(struct dentry *workdir)

{

	struct dentry *temp;

	char name[20];
@@ -68,7 +68,7 @@ static struct dentry *ovl_whiteout(struct dentry *workdir, 
	struct dentry *whiteout;

	struct inode *wdir = workdir->d_inode;



	whiteout = ovl_lookup_temp(workdir, dentry);

	whiteout = ovl_lookup_temp(workdir);

	if (IS_ERR(whiteout))

		return whiteout;
@@ -127,17 +127,28 @@ int ovl_create_real(struct inode *dir, struct dentry *newdentry, 
	return err;

}



static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)

static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper,

			       int xerr)

{

	int err;



	err = ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0);

	err = ovl_check_setxattr(dentry, upper, OVL_XATTR_OPAQUE, "y", 1, xerr);

	if (!err)

		ovl_dentry_set_opaque(dentry);



	return err;

}



static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)

{

	/*

	 * Fail with -EIO when trying to create opaque dir and upper doesn't

	 * support xattrs. ovl_rename() calls ovl_set_opaque_xerr(-EXDEV) to

	 * return a specific error for noxattr case.

	 */

	return ovl_set_opaque_xerr(dentry, upperdentry, -EIO);

}



/* Common operations required to be done after creation of file on upper */

static void ovl_instantiate(struct dentry *dentry, struct inode *inode,

			    struct dentry *newdentry, bool hardlink)
@@ -162,6 +173,11 @@ static bool ovl_type_merge(struct dentry *dentry) 
	return OVL_TYPE_MERGE(ovl_path_type(dentry));

}



static bool ovl_type_origin(struct dentry *dentry)

{

	return OVL_TYPE_ORIGIN(ovl_path_type(dentry));

}



static int ovl_create_upper(struct dentry *dentry, struct inode *inode,

			    struct cattr *attr, struct dentry *hardlink)

{
@@ -250,7 +266,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, 
	if (upper->d_parent->d_inode != udir)

		goto out_unlock;



	opaquedir = ovl_lookup_temp(workdir, dentry);

	opaquedir = ovl_lookup_temp(workdir);

	err = PTR_ERR(opaquedir);

	if (IS_ERR(opaquedir))

		goto out_unlock;
@@ -382,7 +398,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, 
	if (err)

		goto out;



	newdentry = ovl_lookup_temp(workdir, dentry);

	newdentry = ovl_lookup_temp(workdir);

	err = PTR_ERR(newdentry);

	if (IS_ERR(newdentry))

		goto out_unlock;
@@ -846,17 +862,15 @@ static int ovl_set_redirect(struct dentry *dentry, bool samedir) 
	if (IS_ERR(redirect))

		return PTR_ERR(redirect);



	err = ovl_do_setxattr(ovl_dentry_upper(dentry), OVL_XATTR_REDIRECT,

			      redirect, strlen(redirect), 0);

	err = ovl_check_setxattr(dentry, ovl_dentry_upper(dentry),

				 OVL_XATTR_REDIRECT,

				 redirect, strlen(redirect), -EXDEV);

	if (!err) {

		spin_lock(&dentry->d_lock);

		ovl_dentry_set_redirect(dentry, redirect);

		spin_unlock(&dentry->d_lock);

	} else {

		kfree(redirect);

		if (err == -EOPNOTSUPP)

			ovl_clear_redirect_dir(dentry->d_sb);

		else

		pr_warn_ratelimited("overlay: failed to set redirect (%i)\n", err);

		/* Fall back to userspace copy-up */

		err = -EXDEV;
@@ -943,6 +957,25 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, 
	old_upperdir = ovl_dentry_upper(old->d_parent);

	new_upperdir = ovl_dentry_upper(new->d_parent);



	if (!samedir) {

		/*

		 * When moving a merge dir or non-dir with copy up origin into

		 * a new parent, we are marking the new parent dir "impure".

		 * When ovl_iterate() iterates an "impure" upper dir, it will

		 * lookup the origin inodes of the entries to fill d_ino.

		 */

		if (ovl_type_origin(old)) {

			err = ovl_set_impure(new->d_parent, new_upperdir);

			if (err)

				goto out_revert_creds;

		}

		if (!overwrite && ovl_type_origin(new)) {

			err = ovl_set_impure(old->d_parent, old_upperdir);

			if (err)

				goto out_revert_creds;

		}

	}



	trap = lock_rename(new_upperdir, old_upperdir);



	olddentry = lookup_one_len(old->d_name.name, old_upperdir,
@@ -992,7 +1025,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, 
		if (ovl_type_merge_or_lower(old))

			err = ovl_set_redirect(old, samedir);

		else if (!old_opaque && ovl_type_merge(new->d_parent))

			err = ovl_set_opaque(old, olddentry);

			err = ovl_set_opaque_xerr(old, olddentry, -EXDEV);

		if (err)

			goto out_dput;

	}
@@ -1000,7 +1033,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, 
		if (ovl_type_merge_or_lower(new))

			err = ovl_set_redirect(new, samedir);

		else if (!new_opaque && ovl_type_merge(old->d_parent))

			err = ovl_set_opaque(new, newdentry);

			err = ovl_set_opaque_xerr(new, newdentry, -EXDEV);

		if (err)

			goto out_dput;

	}

fs/overlayfs/inode.c

+11 −1
Original line number Diff line number Diff line
@@ -240,6 +240,16 @@ int ovl_xattr_get(struct dentry *dentry, const char *name, 
	return res;

}



static bool ovl_can_list(const char *s)

{

	/* List all non-trusted xatts */

	if (strncmp(s, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) != 0)

		return true;



	/* Never list trusted.overlay, list other trusted for superuser only */

	return !ovl_is_private_xattr(s) && capable(CAP_SYS_ADMIN);

}



ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)

{

	struct dentry *realdentry = ovl_dentry_real(dentry);
@@ -263,7 +273,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) 
			return -EIO;



		len -= slen;

		if (ovl_is_private_xattr(s)) {

		if (!ovl_can_list(s)) {

			res -= slen;

			memmove(s, s + slen, len);

		} else {

fs/overlayfs/namei.c

+5 −11
Original line number Diff line number Diff line
@@ -169,17 +169,7 @@ invalid: 


static bool ovl_is_opaquedir(struct dentry *dentry)

{

	int res;

	char val;



	if (!d_is_dir(dentry))

		return false;



	res = vfs_getxattr(dentry, OVL_XATTR_OPAQUE, &val, 1);

	if (res == 1 && val == 'y')

		return true;



	return false;

	return ovl_check_dir_xattr(dentry, OVL_XATTR_OPAQUE);

}



static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
@@ -351,6 +341,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
	unsigned int ctr = 0;

	struct inode *inode = NULL;

	bool upperopaque = false;

	bool upperimpure = false;

	char *upperredirect = NULL;

	struct dentry *this;

	unsigned int i;
@@ -395,6 +386,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
				poe = roe;

		}

		upperopaque = d.opaque;

		if (upperdentry && d.is_dir)

			upperimpure = ovl_is_impuredir(upperdentry);

	}



	if (!d.stop && poe->numlower) {
@@ -463,6 +456,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 


	revert_creds(old_cred);

	oe->opaque = upperopaque;

	oe->impure = upperimpure;

	oe->redirect = upperredirect;

	oe->__upperdentry = upperdentry;

	memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr);

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