Re: [PATCH 6/6] VFS: Change vfs_mkdir() to return the dentry.

[Chuck Lever <chuck.lever@oracle.com>]

On 2/20/25 6:36 PM, NeilBrown wrote:
> vfs_mkdir() does not guarantee to leave the child dentry hashed or make
> it positive on success, and in many such cases the filesystem had to use
> a different dentry which it can now return.
> 
> This patch changes vfs_mkdir() to return the dentry provided by the
> filesystems which is hashed and positive when provided.  This reduces
> the number of cases where the resulting dentry is not positive to a
> handful which don't deserve extra efforts.
> 
> The only callers of vfs_mkdir() which are interested in the resulting
> inode are in-kernel filesystem clients: cachefiles, nfsd, smb/server.
> The only filesystems that don't reliably provide the inode are:
> - kernfs, tracefs which these clients are unlikely to be interested in
> - cifs in some configurations would need to do a lookup to find the
>   created inode, but doesn't.  cifs cannot be exported via NFS, is
>   unlikely to be used by cachefiles, and smb/server only has a soft
>   requirement for the inode, so this is unlikely to be a problem in
>   practice.
> - hostfs, nfs, cifs may need to do a lookup (rarely for NFS) and it is
>   possible for a race to make that lookup fail.  Actual failure
>   is unlikely and providing callers handle negative dentries graceful
>   they will fail-safe.
> 
> So this patch removes the lookup code in nfsd and smb/server and adjusts
> them to fail safe if a negative dentry is provided:
> - cache-files already fails safe by restarting the task from the
>   top - it still does with this change, though it no longer calls
>   cachefiles_put_directory() as that will crash if the dentry is
>   negative.
> - nfsd reports "Server-fault" which it what it used to do if the lookup
>   failed. This will never happen on any file-systems that it can actually
>   export, so this is of no consequence.  I removed the fh_update()
>   call as that is not needed and out-of-place.  A subsequent
>   nfsd_create_setattr() call will call fh_update() when needed.
> - smb/server only wants the inode to call ksmbd_smb_inherit_owner()
>   which updates ->i_uid (without calling notify_change() or similar)
>   which can be safely skipping on cifs (I hope).
> 
> If a different dentry is returned, the first one is put.  If necessary
> the fact that it is new can be determined by comparing pointers.  A new
> dentry will certainly have a new pointer (as the old is put after the
> new is obtained).
> Similarly if an error is returned (via ERR_PTR()) the original dentry is
> put.
> 
> Signed-off-by: NeilBrown <neilb@suse.de>
> ---
>  drivers/base/devtmpfs.c  |  7 +++---
>  fs/cachefiles/namei.c    | 16 ++++++++------
>  fs/ecryptfs/inode.c      | 14 ++++++++----
>  fs/init.c                |  7 ++++--
>  fs/namei.c               | 46 ++++++++++++++++++++++++++--------------
>  fs/nfsd/nfs4recover.c    |  7 ++++--
>  fs/nfsd/vfs.c            | 34 ++++++++++-------------------
>  fs/overlayfs/dir.c       | 37 ++++----------------------------
>  fs/overlayfs/overlayfs.h | 15 ++++++-------
>  fs/overlayfs/super.c     |  7 +++---
>  fs/smb/server/vfs.c      | 32 +++++++++-------------------
>  fs/xfs/scrub/orphanage.c |  9 ++++----
>  include/linux/fs.h       |  4 ++--
>  13 files changed, 105 insertions(+), 130 deletions(-)
> 
> diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
> index 7a101009bee7..6dd1a8860f1c 100644
> --- a/drivers/base/devtmpfs.c
> +++ b/drivers/base/devtmpfs.c
> @@ -175,18 +175,17 @@ static int dev_mkdir(const char *name, umode_t mode)
>  {
>  	struct dentry *dentry;
>  	struct path path;
> -	int err;
>  
>  	dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
>  	if (IS_ERR(dentry))
>  		return PTR_ERR(dentry);
>  
> -	err = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode);
> -	if (!err)
> +	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode);
> +	if (!IS_ERR(dentry))
>  		/* mark as kernel-created inode */
>  		d_inode(dentry)->i_private = &thread;
>  	done_path_create(&path, dentry);
> -	return err;
> +	return PTR_ERR_OR_ZERO(dentry);
>  }
>  
>  static int create_path(const char *nodepath)
> diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
> index 7cf59713f0f7..83a60126de0f 100644
> --- a/fs/cachefiles/namei.c
> +++ b/fs/cachefiles/namei.c
> @@ -128,18 +128,19 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
>  		ret = security_path_mkdir(&path, subdir, 0700);
>  		if (ret < 0)
>  			goto mkdir_error;
> -		ret = cachefiles_inject_write_error();
> -		if (ret == 0)
> -			ret = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700);
> -		if (ret < 0) {
> +		subdir = ERR_PTR(cachefiles_inject_write_error());
> +		if (!IS_ERR(subdir))
> +			subdir = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700);
> +		ret = PTR_ERR(subdir);
> +		if (IS_ERR(subdir)) {
>  			trace_cachefiles_vfs_error(NULL, d_inode(dir), ret,
>  						   cachefiles_trace_mkdir_error);
>  			goto mkdir_error;
>  		}
>  		trace_cachefiles_mkdir(dir, subdir);
>  
> -		if (unlikely(d_unhashed(subdir))) {
> -			cachefiles_put_directory(subdir);
> +		if (unlikely(d_unhashed(subdir) || d_is_negative(subdir))) {
> +			dput(subdir);
>  			goto retry;
>  		}
>  		ASSERT(d_backing_inode(subdir));
> @@ -195,7 +196,8 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
>  
>  mkdir_error:
>  	inode_unlock(d_inode(dir));
> -	dput(subdir);
> +	if (!IS_ERR(subdir))
> +		dput(subdir);
>  	pr_err("mkdir %s failed with error %d\n", dirname, ret);
>  	return ERR_PTR(ret);
>  
> diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
> index 6315dd194228..51a5c54eb740 100644
> --- a/fs/ecryptfs/inode.c
> +++ b/fs/ecryptfs/inode.c
> @@ -511,10 +511,16 @@ static struct dentry *ecryptfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
>  	struct inode *lower_dir;
>  
>  	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
> -	if (!rc)
> -		rc = vfs_mkdir(&nop_mnt_idmap, lower_dir,
> -			       lower_dentry, mode);
> -	if (rc || d_really_is_negative(lower_dentry))
> +	if (rc)
> +		goto out;
> +
> +	lower_dentry = vfs_mkdir(&nop_mnt_idmap, lower_dir,
> +				 lower_dentry, mode);
> +	rc = PTR_ERR(lower_dentry);
> +	if (IS_ERR(lower_dentry))
> +		goto out;
> +	rc = 0;
> +	if (d_unhashed(lower_dentry))
>  		goto out;
>  	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
>  	if (rc)
> diff --git a/fs/init.c b/fs/init.c
> index e9387b6c4f30..eef5124885e3 100644
> --- a/fs/init.c
> +++ b/fs/init.c
> @@ -230,9 +230,12 @@ int __init init_mkdir(const char *pathname, umode_t mode)
>  		return PTR_ERR(dentry);
>  	mode = mode_strip_umask(d_inode(path.dentry), mode);
>  	error = security_path_mkdir(&path, dentry, mode);
> -	if (!error)
> -		error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
> +	if (!error) {
> +		dentry = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
>  				  dentry, mode);
> +		if (IS_ERR(dentry))
> +			error = PTR_ERR(dentry);
> +	}
>  	done_path_create(&path, dentry);
>  	return error;
>  }
> diff --git a/fs/namei.c b/fs/namei.c
> index 63fe4dc29c23..bd5eec2c0af4 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -4125,7 +4125,8 @@ EXPORT_SYMBOL(kern_path_create);
>  
>  void done_path_create(struct path *path, struct dentry *dentry)
>  {
> -	dput(dentry);
> +	if (!IS_ERR(dentry))
> +		dput(dentry);
>  	inode_unlock(path->dentry->d_inode);
>  	mnt_drop_write(path->mnt);
>  	path_put(path);
> @@ -4271,7 +4272,7 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
>  }
>  
>  /**
> - * vfs_mkdir - create directory
> + * vfs_mkdir - create directory returning correct dentry if possible
>   * @idmap:	idmap of the mount the inode was found from
>   * @dir:	inode of the parent directory
>   * @dentry:	dentry of the child directory
> @@ -4284,9 +4285,15 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
>   * care to map the inode according to @idmap before checking permissions.
>   * On non-idmapped mounts or if permission checking is to be performed on the
>   * raw inode simply pass @nop_mnt_idmap.
> + *
> + * In the event that the filesystem does not use the *@dentry but leaves it
> + * negative or unhashes it and possibly splices a different one returning it,
> + * the original dentry is dput() and the alternate is returned.
> + *
> + * In case of an error the dentry is dput() and an ERR_PTR() is returned.
>   */
> -int vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
> -	      struct dentry *dentry, umode_t mode)
> +struct dentry *vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
> +			 struct dentry *dentry, umode_t mode)
>  {
>  	int error;
>  	unsigned max_links = dir->i_sb->s_max_links;
> @@ -4294,31 +4301,36 @@ int vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
>  
>  	error = may_create(idmap, dir, dentry);
>  	if (error)
> -		return error;
> +		goto err;
>  
> +	error = -EPERM;
>  	if (!dir->i_op->mkdir)
> -		return -EPERM;
> +		goto err;
>  
>  	mode = vfs_prepare_mode(idmap, dir, mode, S_IRWXUGO | S_ISVTX, 0);
>  	error = security_inode_mkdir(dir, dentry, mode);
>  	if (error)
> -		return error;
> +		goto err;
>  
> +	error = -EMLINK;
>  	if (max_links && dir->i_nlink >= max_links)
> -		return -EMLINK;
> +		goto err;
>  
>  	de = dir->i_op->mkdir(idmap, dir, dentry, mode);
> +	error = PTR_ERR(de);
>  	if (IS_ERR(de))
> -		return PTR_ERR(de);
> +		goto err;
>  	if (de) {
> -		fsnotify_mkdir(dir, de);
> -		/* Cannot return de yet */
> -		dput(de);
> -	} else {
> -		fsnotify_mkdir(dir, dentry);
> +		dput(dentry);
> +		dentry = de;
>  	}
> +	fsnotify_mkdir(dir, dentry);
> +	return dentry;
>  
> -	return 0;
> +err:
> +	dput(dentry);
> +
> +	return ERR_PTR(error);
>  }
>  EXPORT_SYMBOL(vfs_mkdir);
>  
> @@ -4338,8 +4350,10 @@ int do_mkdirat(int dfd, struct filename *name, umode_t mode)
>  	error = security_path_mkdir(&path, dentry,
>  			mode_strip_umask(path.dentry->d_inode, mode));
>  	if (!error) {
> -		error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
> +		dentry = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
>  				  dentry, mode);
> +		if (IS_ERR(dentry))
> +			error = PTR_ERR(dentry);
>  	}
>  	done_path_create(&path, dentry);
>  	if (retry_estale(error, lookup_flags)) {
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index 28f4d5311c40..c1d9bd07285f 100644
> --- a/fs/nfsd/nfs4recover.c
> +++ b/fs/nfsd/nfs4recover.c
> @@ -233,9 +233,12 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
>  		 * as well be forgiving and just succeed silently.
>  		 */
>  		goto out_put;
> -	status = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU);
> +	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU);
> +	if (IS_ERR(dentry))
> +		status = PTR_ERR(dentry);
>  out_put:
> -	dput(dentry);
> +	if (!status)
> +		dput(dentry);
>  out_unlock:
>  	inode_unlock(d_inode(dir));
>  	if (status == 0) {
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 29cb7b812d71..34d7aa531662 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -1461,7 +1461,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  	struct inode	*dirp;
>  	struct iattr	*iap = attrs->na_iattr;
>  	__be32		err;
> -	int		host_err;
> +	int		host_err = 0;
>  
>  	dentry = fhp->fh_dentry;
>  	dirp = d_inode(dentry);
> @@ -1488,28 +1488,15 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  			nfsd_check_ignore_resizing(iap);
>  		break;
>  	case S_IFDIR:
> -		host_err = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode);
> -		if (!host_err && unlikely(d_unhashed(dchild))) {
> -			struct dentry *d;
> -			d = lookup_one_len(dchild->d_name.name,
> -					   dchild->d_parent,
> -					   dchild->d_name.len);
> -			if (IS_ERR(d)) {
> -				host_err = PTR_ERR(d);
> -				break;
> -			}
> -			if (unlikely(d_is_negative(d))) {
> -				dput(d);
> -				err = nfserr_serverfault;
> -				goto out;
> -			}
> +		dchild = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode);
> +		if (IS_ERR(dchild)) {
> +			host_err = PTR_ERR(dchild);
> +		} else if (d_is_negative(dchild)) {
> +			err = nfserr_serverfault;
> +			goto out;
> +		} else if (unlikely(dchild != resfhp->fh_dentry)) {
>  			dput(resfhp->fh_dentry);
> -			resfhp->fh_dentry = dget(d);
> -			err = fh_update(resfhp);

Hi Neil, why is this fh_update() call no longer necessary?


> -			dput(dchild);
> -			dchild = d;
> -			if (err)
> -				goto out;
> +			resfhp->fh_dentry = dget(dchild);
>  		}
>  		break;
>  	case S_IFCHR:
> @@ -1530,7 +1517,8 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  	err = nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
>  
>  out:
> -	dput(dchild);
> +	if (!IS_ERR(dchild))
> +		dput(dchild);
>  	return err;
>  
>  out_nfserr:
> diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
> index 21c3aaf7b274..fe493f3ed6b6 100644
> --- a/fs/overlayfs/dir.c
> +++ b/fs/overlayfs/dir.c
> @@ -138,37 +138,6 @@ int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
>  	goto out;
>  }
>  
> -int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
> -		   struct dentry **newdentry, umode_t mode)
> -{
> -	int err;
> -	struct dentry *d, *dentry = *newdentry;
> -
> -	err = ovl_do_mkdir(ofs, dir, dentry, mode);
> -	if (err)
> -		return err;
> -
> -	if (likely(!d_unhashed(dentry)))
> -		return 0;
> -
> -	/*
> -	 * vfs_mkdir() may succeed and leave the dentry passed
> -	 * to it unhashed and negative. If that happens, try to
> -	 * lookup a new hashed and positive dentry.
> -	 */
> -	d = ovl_lookup_upper(ofs, dentry->d_name.name, dentry->d_parent,
> -			     dentry->d_name.len);
> -	if (IS_ERR(d)) {
> -		pr_warn("failed lookup after mkdir (%pd2, err=%i).\n",
> -			dentry, err);
> -		return PTR_ERR(d);
> -	}
> -	dput(dentry);
> -	*newdentry = d;
> -
> -	return 0;
> -}
> -
>  struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
>  			       struct dentry *newdentry, struct ovl_cattr *attr)
>  {
> @@ -191,7 +160,8 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
>  
>  		case S_IFDIR:
>  			/* mkdir is special... */
> -			err =  ovl_mkdir_real(ofs, dir, &newdentry, attr->mode);
> +			newdentry =  ovl_do_mkdir(ofs, dir, newdentry, attr->mode);
> +			err = PTR_ERR_OR_ZERO(newdentry);
>  			break;
>  
>  		case S_IFCHR:
> @@ -219,7 +189,8 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
>  	}
>  out:
>  	if (err) {
> -		dput(newdentry);
> +		if (!IS_ERR(newdentry))
> +			dput(newdentry);
>  		return ERR_PTR(err);
>  	}
>  	return newdentry;
> diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
> index 0021e2025020..6f2f8f4cfbbc 100644
> --- a/fs/overlayfs/overlayfs.h
> +++ b/fs/overlayfs/overlayfs.h
> @@ -241,13 +241,14 @@ static inline int ovl_do_create(struct ovl_fs *ofs,
>  	return err;
>  }
>  
> -static inline int ovl_do_mkdir(struct ovl_fs *ofs,
> -			       struct inode *dir, struct dentry *dentry,
> -			       umode_t mode)
> +static inline struct dentry *ovl_do_mkdir(struct ovl_fs *ofs,
> +					  struct inode *dir,
> +					  struct dentry *dentry,
> +					  umode_t mode)
>  {
> -	int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
> -	pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
> -	return err;
> +	dentry = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
> +	pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(dentry));
> +	return dentry;
>  }
>  
>  static inline int ovl_do_mknod(struct ovl_fs *ofs,
> @@ -838,8 +839,6 @@ struct ovl_cattr {
>  
>  #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
>  
> -int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
> -		   struct dentry **newdentry, umode_t mode);
>  struct dentry *ovl_create_real(struct ovl_fs *ofs,
>  			       struct inode *dir, struct dentry *newdentry,
>  			       struct ovl_cattr *attr);
> diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
> index 61e21c3129e8..b63474d1b064 100644
> --- a/fs/overlayfs/super.c
> +++ b/fs/overlayfs/super.c
> @@ -327,9 +327,10 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
>  			goto retry;
>  		}
>  
> -		err = ovl_mkdir_real(ofs, dir, &work, attr.ia_mode);
> -		if (err)
> -			goto out_dput;
> +		work = ovl_do_mkdir(ofs, dir, work, attr.ia_mode);
> +		err = PTR_ERR(work);
> +		if (IS_ERR(work))
> +			goto out_err;
>  
>  		/* Weird filesystem returning with hashed negative (kernfs)? */
>  		err = -EINVAL;
> diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
> index fe29acef5872..8554aa5a1059 100644
> --- a/fs/smb/server/vfs.c
> +++ b/fs/smb/server/vfs.c
> @@ -206,8 +206,8 @@ int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)
>  {
>  	struct mnt_idmap *idmap;
>  	struct path path;
> -	struct dentry *dentry;
> -	int err;
> +	struct dentry *dentry, *d;
> +	int err = 0;
>  
>  	dentry = ksmbd_vfs_kern_path_create(work, name,
>  					    LOOKUP_NO_SYMLINKS | LOOKUP_DIRECTORY,
> @@ -222,27 +222,15 @@ int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)
>  
>  	idmap = mnt_idmap(path.mnt);
>  	mode |= S_IFDIR;
> -	err = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode);
> -	if (!err && d_unhashed(dentry)) {
> -		struct dentry *d;
> -
> -		d = lookup_one(idmap, dentry->d_name.name, dentry->d_parent,
> -			       dentry->d_name.len);
> -		if (IS_ERR(d)) {
> -			err = PTR_ERR(d);
> -			goto out_err;
> -		}
> -		if (unlikely(d_is_negative(d))) {
> -			dput(d);
> -			err = -ENOENT;
> -			goto out_err;
> -		}
> -
> -		ksmbd_vfs_inherit_owner(work, d_inode(path.dentry), d_inode(d));
> -		dput(d);
> -	}
> +	d = dentry;
> +	dentry = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode);
> +	if (IS_ERR(dentry))
> +		err = PTR_ERR(dentry);
> +	else if (d_is_negative(dentry))
> +		err = -ENOENT;
> +	if (!err && dentry != d)
> +		ksmbd_vfs_inherit_owner(work, d_inode(path.dentry), d_inode(dentry));
>  
> -out_err:
>  	done_path_create(&path, dentry);
>  	if (err)
>  		pr_err("mkdir(%s): creation failed (err:%d)\n", name, err);
> diff --git a/fs/xfs/scrub/orphanage.c b/fs/xfs/scrub/orphanage.c
> index c287c755f2c5..3537f3cca6d5 100644
> --- a/fs/xfs/scrub/orphanage.c
> +++ b/fs/xfs/scrub/orphanage.c
> @@ -167,10 +167,11 @@ xrep_orphanage_create(
>  	 * directory to control access to a file we put in here.
>  	 */
>  	if (d_really_is_negative(orphanage_dentry)) {
> -		error = vfs_mkdir(&nop_mnt_idmap, root_inode, orphanage_dentry,
> -				0750);
> -		if (error)
> -			goto out_dput_orphanage;
> +		orphanage_dentry = vfs_mkdir(&nop_mnt_idmap, root_inode,
> +					     orphanage_dentry, 0750);
> +		error = PTR_ERR(orphanage_dentry);
> +		if (IS_ERR(orphanage_dentry))
> +			goto out_unlock_root;
>  	}
>  
>  	/* Not a directory? Bail out. */
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 8f4fbecd40fc..eaad8e31c0d4 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1971,8 +1971,8 @@ bool inode_owner_or_capable(struct mnt_idmap *idmap,
>   */
>  int vfs_create(struct mnt_idmap *, struct inode *,
>  	       struct dentry *, umode_t, bool);
> -int vfs_mkdir(struct mnt_idmap *, struct inode *,
> -	      struct dentry *, umode_t);
> +struct dentry *vfs_mkdir(struct mnt_idmap *, struct inode *,
> +			 struct dentry *, umode_t);
>  int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
>                umode_t, dev_t);
>  int vfs_symlink(struct mnt_idmap *, struct inode *,


-- 
Chuck Lever