Commit 21a22878 authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: handle rename when upper doesn't support xattr 



On failure to set opaque/redirect xattr on rename, skip setting xattr and
return -EXDEV.

On failure to set opaque xattr when creating a new directory, -EIO is
returned instead of -EOPNOTSUPP.

Any failure to set those xattr will be recorded in super block and
then setting any xattr on upper won't be attempted again.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 6266d465

fs/overlayfs/dir.c

+19 −10
Original line number Diff line number Diff line
@@ -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)
@@ -846,17 +857,15 @@ 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;
@@ -992,7 +1001,7 @@ 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 +1009,7 @@ 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/overlayfs.h

+0 −1
Original line number Diff line number Diff line
@@ -206,7 +206,6 @@ bool ovl_dentry_is_opaque(struct dentry *dentry); 
bool ovl_dentry_is_whiteout(struct dentry *dentry);

void ovl_dentry_set_opaque(struct dentry *dentry);

bool ovl_redirect_dir(struct super_block *sb);

void ovl_clear_redirect_dir(struct super_block *sb);

const char *ovl_dentry_get_redirect(struct dentry *dentry);

void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);

void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);

fs/overlayfs/util.c

+1 −8
Original line number Diff line number Diff line
@@ -191,14 +191,7 @@ bool ovl_redirect_dir(struct super_block *sb) 
{

	struct ovl_fs *ofs = sb->s_fs_info;



	return ofs->config.redirect_dir;

}



void ovl_clear_redirect_dir(struct super_block *sb)

{

	struct ovl_fs *ofs = sb->s_fs_info;



	ofs->config.redirect_dir = false;

	return ofs->config.redirect_dir && !ofs->noxattr;

}



const char *ovl_dentry_get_redirect(struct dentry *dentry)

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