Commit 610afc0b authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

ovl: pass ovl_fs down to functions accessing private xattrs 



This paves the way for optionally using the "user.overlay." xattr
namespace.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 26150ab5

fs/overlayfs/copy_up.c

+9 −7
Original line number Diff line number Diff line
@@ -43,7 +43,8 @@ static bool ovl_must_copy_xattr(const char *name) 
	       !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN);

}



int ovl_copy_xattr(struct dentry *old, struct dentry *new)

int ovl_copy_xattr(struct super_block *sb, struct dentry *old,

		   struct dentry *new)

{

	ssize_t list_size, size, value_size = 0;

	char *buf, *name, *value = NULL;
@@ -81,7 +82,7 @@ int ovl_copy_xattr(struct dentry *old, struct dentry *new) 
		}

		list_size -= slen;



		if (ovl_is_private_xattr(name))

		if (ovl_is_private_xattr(sb, name))

			continue;

retry:

		size = vfs_getxattr(old, name, value, value_size);
@@ -355,7 +356,8 @@ int ovl_set_origin(struct dentry *dentry, struct dentry *lower, 
}



/* Store file handle of @upper dir in @index dir entry */

static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index)

static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper,

			    struct dentry *index)

{

	const struct ovl_fh *fh;

	int err;
@@ -364,7 +366,7 @@ static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index) 
	if (IS_ERR(fh))

		return PTR_ERR(fh);



	err = ovl_do_setxattr(index, OVL_XATTR_UPPER, fh->buf, fh->fb.len);

	err = ovl_do_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len);



	kfree(fh);

	return err;
@@ -409,7 +411,7 @@ static int ovl_create_index(struct dentry *dentry, struct dentry *origin, 
	if (IS_ERR(temp))

		goto free_name;



	err = ovl_set_upper_fh(upper, temp);

	err = ovl_set_upper_fh(OVL_FS(dentry->d_sb), upper, temp);

	if (err)

		goto out;
@@ -507,7 +509,7 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) 
			return err;

	}



	err = ovl_copy_xattr(c->lowerpath.dentry, temp);

	err = ovl_copy_xattr(c->dentry->d_sb, c->lowerpath.dentry, temp);

	if (err)

		return err;
@@ -847,7 +849,7 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) 
	}





	err = ovl_do_removexattr(upperpath.dentry, OVL_XATTR_METACOPY);

	err = ovl_do_removexattr(ofs, upperpath.dentry, OVL_XATTR_METACOPY);

	if (err)

		goto out_free;

fs/overlayfs/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -394,7 +394,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, 
	if (IS_ERR(opaquedir))

		goto out_unlock;



	err = ovl_copy_xattr(upper, opaquedir);

	err = ovl_copy_xattr(dentry->d_sb, upper, opaquedir);

	if (err)

		goto out_cleanup;

fs/overlayfs/export.c

+1 −1
Original line number Diff line number Diff line
@@ -752,7 +752,7 @@ static struct dentry *ovl_lower_fh_to_d(struct super_block *sb, 
			goto out_err;

	}

	if (index) {

		err = ovl_verify_origin(index, origin.dentry, false);

		err = ovl_verify_origin(ofs, index, origin.dentry, false);

		if (err)

			goto out_err;

	}

fs/overlayfs/inode.c

+12 −10
Original line number Diff line number Diff line
@@ -327,7 +327,7 @@ static const char *ovl_get_link(struct dentry *dentry, 
	return p;

}



bool ovl_is_private_xattr(const char *name)

bool ovl_is_private_xattr(struct super_block *sb, const char *name)

{

	return strncmp(name, OVL_XATTR_PREFIX,

		       sizeof(OVL_XATTR_PREFIX) - 1) == 0;
@@ -391,14 +391,14 @@ int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, 
	return res;

}



static bool ovl_can_list(const char *s)

static bool ovl_can_list(struct super_block *sb, 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) &&

	return !ovl_is_private_xattr(sb, s) &&

	       ns_capable_noaudit(&init_user_ns, CAP_SYS_ADMIN);

}
@@ -425,7 +425,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) 
			return -EIO;



		len -= slen;

		if (!ovl_can_list(s)) {

		if (!ovl_can_list(dentry->d_sb, s)) {

			res -= slen;

			memmove(s, s + slen, len);

		} else {
@@ -722,7 +722,7 @@ static int ovl_set_nlink_common(struct dentry *dentry, 
	if (WARN_ON(len >= sizeof(buf)))

		return -EIO;



	return ovl_do_setxattr(ovl_dentry_upper(dentry),

	return ovl_do_setxattr(OVL_FS(inode->i_sb), ovl_dentry_upper(dentry),

			       OVL_XATTR_NLINK, buf, len);

}
@@ -736,7 +736,7 @@ int ovl_set_nlink_lower(struct dentry *dentry) 
	return ovl_set_nlink_common(dentry, ovl_dentry_lower(dentry), "L%+i");

}



unsigned int ovl_get_nlink(struct dentry *lowerdentry,

unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry,

			   struct dentry *upperdentry,

			   unsigned int fallback)

{
@@ -748,7 +748,7 @@ unsigned int ovl_get_nlink(struct dentry *lowerdentry, 
	if (!lowerdentry || !upperdentry || d_inode(lowerdentry)->i_nlink == 1)

		return fallback;



	err = ovl_do_getxattr(upperdentry, OVL_XATTR_NLINK,

	err = ovl_do_getxattr(ofs, upperdentry, OVL_XATTR_NLINK,

			      &buf, sizeof(buf) - 1);

	if (err < 0)

		goto fail;
@@ -947,6 +947,7 @@ static struct inode *ovl_iget5(struct super_block *sb, struct inode *newinode, 
struct inode *ovl_get_inode(struct super_block *sb,

			    struct ovl_inode_params *oip)

{

	struct ovl_fs *ofs = OVL_FS(sb);

	struct dentry *upperdentry = oip->upperdentry;

	struct ovl_path *lowerpath = oip->lowerpath;

	struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
@@ -994,7 +995,8 @@ struct inode *ovl_get_inode(struct super_block *sb, 


		/* Recalculate nlink for non-dir due to indexing */

		if (!is_dir)

			nlink = ovl_get_nlink(lowerdentry, upperdentry, nlink);

			nlink = ovl_get_nlink(ofs, lowerdentry, upperdentry,

					      nlink);

		set_nlink(inode, nlink);

		ino = key->i_ino;

	} else {
@@ -1010,7 +1012,7 @@ struct inode *ovl_get_inode(struct super_block *sb, 
	ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev);

	ovl_inode_init(inode, oip, ino, fsid);



	if (upperdentry && ovl_is_impuredir(upperdentry))

	if (upperdentry && ovl_is_impuredir(sb, upperdentry))

		ovl_set_flag(OVL_IMPURE, inode);



	if (oip->index)
@@ -1024,7 +1026,7 @@ struct inode *ovl_get_inode(struct super_block *sb, 
	/* Check for non-merge dir that may have whiteouts */

	if (is_dir) {

		if (((upperdentry && lowerdentry) || oip->numlower > 1) ||

		    ovl_check_origin_xattr(upperdentry ?: lowerdentry)) {

		    ovl_check_origin_xattr(ofs, upperdentry ?: lowerdentry)) {

			ovl_set_flag(OVL_WHITEOUTS, inode);

		}

	}

fs/overlayfs/namei.c

+30 −27
Original line number Diff line number Diff line
@@ -30,8 +30,9 @@ static int ovl_check_redirect(struct dentry *dentry, struct ovl_lookup_data *d, 
{

	int res;

	char *buf;

	struct ovl_fs *ofs = OVL_FS(d->sb);



	buf = ovl_get_redirect_xattr(dentry, prelen + strlen(post));

	buf = ovl_get_redirect_xattr(ofs, dentry, prelen + strlen(post));

	if (IS_ERR_OR_NULL(buf))

		return PTR_ERR(buf);
@@ -104,12 +105,13 @@ int ovl_check_fb_len(struct ovl_fb *fb, int fb_len) 
	return 0;

}



static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)

static struct ovl_fh *ovl_get_fh(struct ovl_fs *ofs, struct dentry *dentry,

				 const char *name)

{

	int res, err;

	struct ovl_fh *fh = NULL;



	res = ovl_do_getxattr(dentry, name, NULL, 0);

	res = ovl_do_getxattr(ofs, dentry, name, NULL, 0);

	if (res < 0) {

		if (res == -ENODATA || res == -EOPNOTSUPP)

			return NULL;
@@ -123,7 +125,7 @@ static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name) 
	if (!fh)

		return ERR_PTR(-ENOMEM);



	res = ovl_do_getxattr(dentry, name, fh->buf, res);

	res = ovl_do_getxattr(ofs, dentry, name, fh->buf, res);

	if (res < 0)

		goto fail;
@@ -186,9 +188,9 @@ struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt, 
	return real;

}



static bool ovl_is_opaquedir(struct dentry *dentry)

static bool ovl_is_opaquedir(struct super_block *sb, struct dentry *dentry)

{

	return ovl_check_dir_xattr(dentry, OVL_XATTR_OPAQUE);

	return ovl_check_dir_xattr(sb, dentry, OVL_XATTR_OPAQUE);

}



static struct dentry *ovl_lookup_positive_unlocked(const char *name,
@@ -251,7 +253,7 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, 
			d->stop = true;

			goto put_and_out;

		}

		err = ovl_check_metacopy_xattr(this);

		err = ovl_check_metacopy_xattr(OVL_FS(d->sb), this);

		if (err < 0)

			goto out_err;
@@ -271,7 +273,7 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d, 
		if (d->last)

			goto out;



		if (ovl_is_opaquedir(this)) {

		if (ovl_is_opaquedir(d->sb, this)) {

			d->stop = true;

			if (last_element)

				d->opaque = true;
@@ -391,7 +393,7 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 
static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,

			    struct ovl_path **stackp)

{

	struct ovl_fh *fh = ovl_get_fh(upperdentry, OVL_XATTR_ORIGIN);

	struct ovl_fh *fh = ovl_get_fh(ofs, upperdentry, OVL_XATTR_ORIGIN);

	int err;



	if (IS_ERR_OR_NULL(fh))
@@ -413,10 +415,10 @@ static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry, 
 * Verify that @fh matches the file handle stored in xattr @name.

 * Return 0 on match, -ESTALE on mismatch, < 0 on error.

 */

static int ovl_verify_fh(struct dentry *dentry, const char *name,

			 const struct ovl_fh *fh)

static int ovl_verify_fh(struct ovl_fs *ofs, struct dentry *dentry,

			 const char *name, const struct ovl_fh *fh)

{

	struct ovl_fh *ofh = ovl_get_fh(dentry, name);

	struct ovl_fh *ofh = ovl_get_fh(ofs, dentry, name);

	int err = 0;



	if (!ofh)
@@ -440,8 +442,9 @@ static int ovl_verify_fh(struct dentry *dentry, const char *name, 
 *

 * Return 0 on match, -ESTALE on mismatch, -ENODATA on no xattr, < 0 on error.

 */

int ovl_verify_set_fh(struct dentry *dentry, const char *name,

		      struct dentry *real, bool is_upper, bool set)

int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,

		      const char *name, struct dentry *real, bool is_upper,

		      bool set)

{

	struct inode *inode;

	struct ovl_fh *fh;
@@ -454,9 +457,9 @@ int ovl_verify_set_fh(struct dentry *dentry, const char *name, 
		goto fail;

	}



	err = ovl_verify_fh(dentry, name, fh);

	err = ovl_verify_fh(ofs, dentry, name, fh);

	if (set && err == -ENODATA)

		err = ovl_do_setxattr(dentry, name, fh->buf, fh->fb.len);

		err = ovl_do_setxattr(ofs, dentry, name, fh->buf, fh->fb.len);

	if (err)

		goto fail;
@@ -481,7 +484,7 @@ struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index) 
	if (!d_is_dir(index))

		return dget(index);



	fh = ovl_get_fh(index, OVL_XATTR_UPPER);

	fh = ovl_get_fh(ofs, index, OVL_XATTR_UPPER);

	if (IS_ERR_OR_NULL(fh))

		return ERR_CAST(fh);
@@ -574,7 +577,7 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index) 
		goto fail;

	}



	err = ovl_verify_fh(upper, OVL_XATTR_ORIGIN, fh);

	err = ovl_verify_fh(ofs, upper, OVL_XATTR_ORIGIN, fh);

	dput(upper);

	if (err)

		goto fail;
@@ -585,7 +588,7 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index) 
		if (err)

			goto fail;



		if (ovl_get_nlink(origin.dentry, index, 0) == 0)

		if (ovl_get_nlink(ofs, origin.dentry, index, 0) == 0)

			goto orphan;

	}
@@ -741,7 +744,7 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 
		}



		/* Verify that dir index 'upper' xattr points to upper dir */

		err = ovl_verify_upper(index, upper, false);

		err = ovl_verify_upper(ofs, index, upper, false);

		if (err) {

			if (err == -ESTALE) {

				pr_warn_ratelimited("suspected multiply redirected dir found (upper=%pd2, origin=%pd2, index=%pd2).\n",
@@ -790,12 +793,12 @@ int ovl_path_next(int idx, struct dentry *dentry, struct path *path) 
}



/* Fix missing 'origin' xattr */

static int ovl_fix_origin(struct dentry *dentry, struct dentry *lower,

			  struct dentry *upper)

static int ovl_fix_origin(struct ovl_fs *ofs, struct dentry *dentry,

			  struct dentry *lower, struct dentry *upper)

{

	int err;



	if (ovl_check_origin_xattr(upper))

	if (ovl_check_origin_xattr(ofs, upper))

		return 0;



	err = ovl_want_write(dentry);
@@ -920,7 +923,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
		 * of lower dir and set upper parent "impure".

		 */

		if (upperdentry && !ctr && !ofs->noxattr && d.is_dir) {

			err = ovl_fix_origin(dentry, this, upperdentry);

			err = ovl_fix_origin(ofs, dentry, this, upperdentry);

			if (err) {

				dput(this);

				goto out_put;
@@ -939,7 +942,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
		if (upperdentry && !ctr &&

		    ((d.is_dir && ovl_verify_lower(dentry->d_sb)) ||

		     (!d.is_dir && ofs->config.index && origin_path))) {

			err = ovl_verify_origin(upperdentry, this, false);

			err = ovl_verify_origin(ofs, upperdentry, this, false);

			if (err) {

				dput(this);

				if (d.is_dir)
@@ -1060,13 +1063,13 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 
		ovl_dentry_set_upper_alias(dentry);

	else if (index) {

		upperdentry = dget(index);

		upperredirect = ovl_get_redirect_xattr(upperdentry, 0);

		upperredirect = ovl_get_redirect_xattr(ofs, upperdentry, 0);

		if (IS_ERR(upperredirect)) {

			err = PTR_ERR(upperredirect);

			upperredirect = NULL;

			goto out_free_oe;

		}

		err = ovl_check_metacopy_xattr(upperdentry);

		err = ovl_check_metacopy_xattr(ofs, upperdentry);

		if (err < 0)

			goto out_free_oe;

		uppermetacopy = err;