[PATCH RFC 04/24] vfs: allow mkdir to wait for delegation break on parent

[Jeff Layton <jlayton@kernel.org>]

In order to add directory delegation support, we need to break
delegations on the parent whenever there is going to be a change in the
directory.

Add a new delegated_inode parameter to vfs_mkdir. Most callers will set
that to NULL, but do_mkdirat can use that to wait for the delegation
break to complete and then retry.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 drivers/base/devtmpfs.c  |  2 +-
 fs/cachefiles/namei.c    |  2 +-
 fs/ecryptfs/inode.c      |  2 +-
 fs/init.c                |  2 +-
 fs/namei.c               | 17 +++++++++++++----
 fs/nfsd/nfs4recover.c    |  2 +-
 fs/nfsd/vfs.c            |  2 +-
 fs/overlayfs/overlayfs.h |  2 +-
 fs/smb/server/vfs.c      |  2 +-
 include/linux/fs.h       |  2 +-
 10 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index b848764ef018..8d1dbcad69f7 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -166,7 +166,7 @@ static int dev_mkdir(const char *name, umode_t mode)
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
-	err = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode);
+	err = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode, NULL);
 	if (!err)
 		/* mark as kernel-created inode */
 		d_inode(dentry)->i_private = &thread;
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 7ade836beb58..4e3e31320275 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -130,7 +130,7 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 			goto mkdir_error;
 		ret = cachefiles_inject_write_error();
 		if (ret == 0)
-			ret = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700);
+			ret = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700, NULL);
 		if (ret < 0) {
 			trace_cachefiles_vfs_error(NULL, d_inode(dir), ret,
 						   cachefiles_trace_mkdir_error);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 5ed1e4cf6c0b..d26b4484fa60 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -513,7 +513,7 @@ static int ecryptfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
 	if (!rc)
 		rc = vfs_mkdir(&nop_mnt_idmap, lower_dir,
-			       lower_dentry, mode);
+			       lower_dentry, mode, NULL);
 	if (rc || d_really_is_negative(lower_dentry))
 		goto out;
 	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
diff --git a/fs/init.c b/fs/init.c
index e9387b6c4f30..325c9e4d9b20 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -232,7 +232,7 @@ int __init init_mkdir(const char *pathname, umode_t mode)
 	error = security_path_mkdir(&path, dentry, mode);
 	if (!error)
 		error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
-				  dentry, mode);
+				  dentry, mode, NULL);
 	done_path_create(&path, dentry);
 	return error;
 }
diff --git a/fs/namei.c b/fs/namei.c
index 56d3ebed7bac..6a22517f9938 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4103,7 +4103,7 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
  * raw inode simply pass @nop_mnt_idmap.
  */
 int vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
-	      struct dentry *dentry, umode_t mode)
+	      struct dentry *dentry, umode_t mode, struct inode **delegated_inode)
 {
 	int error;
 	unsigned max_links = dir->i_sb->s_max_links;
@@ -4123,6 +4123,10 @@ int vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	if (max_links && dir->i_nlink >= max_links)
 		return -EMLINK;
 
+	error = try_break_deleg(dir, delegated_inode);
+	if (error)
+		return error;
+
 	error = dir->i_op->mkdir(idmap, dir, dentry, mode);
 	if (!error)
 		fsnotify_mkdir(dir, dentry);
@@ -4136,6 +4140,7 @@ int do_mkdirat(int dfd, struct filename *name, umode_t mode)
 	struct path path;
 	int error;
 	unsigned int lookup_flags = LOOKUP_DIRECTORY;
+	struct inode *delegated_inode = NULL;
 
 retry:
 	dentry = filename_create(dfd, name, &path, lookup_flags);
@@ -4145,11 +4150,15 @@ 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) {
+	if (!error)
 		error = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
-				  dentry, mode);
-	}
+				  dentry, mode, &delegated_inode);
 	done_path_create(&path, dentry);
+	if (delegated_inode) {
+		error = break_deleg_wait(&delegated_inode);
+		if (!error)
+			goto retry;
+	}
 	if (retry_estale(error, lookup_flags)) {
 		lookup_flags |= LOOKUP_REVAL;
 		goto retry;
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 2c060e0b1604..5bfced783a70 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -234,7 +234,7 @@ 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);
+	status = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU, NULL);
 out_put:
 	dput(dentry);
 out_unlock:
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 6a4c506038e0..e42e58825590 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1496,7 +1496,7 @@ 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);
+		host_err = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode, NULL);
 		if (!host_err && unlikely(d_unhashed(dchild))) {
 			struct dentry *d;
 			d = lookup_one_len(dchild->d_name.name,
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index ee949f3e7c77..baa371947f86 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -242,7 +242,7 @@ static inline int 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);
+	int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, NULL);
 	pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
 	return err;
 }
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index c487e834331a..3760e0dda349 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -227,7 +227,7 @@ 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);
+	err = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode, NULL);
 	if (!err && d_unhashed(dentry)) {
 		struct dentry *d;
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8dfcddafdb3d..18eb7d628290 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1839,7 +1839,7 @@ 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 *, umode_t, struct inode **);
 int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
               umode_t, dev_t);
 int vfs_symlink(struct mnt_idmap *, struct inode *,

-- 
2.44.0