From 4be9f3cc582a24b08f6580f65fa48a4d70332ab5 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:43 -0500
Subject: filelock: rework the __break_lease API to use flags

Currently __break_lease takes both a type and an openmode. With the
addition of directory leases, that makes less sense. Declare a set of
LEASE_BREAK_* flags that can be used to control how lease breaks work
instead of requiring a type and an openmode.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-2-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 include/linux/filelock.h | 52 +++++++++++++++++++++++++++++++++++-------------
 1 file changed, 38 insertions(+), 14 deletions(-)

(limited to 'include')

diff --git a/include/linux/filelock.h b/include/linux/filelock.h
index c2ce8ba05d06..47da6aa28d8d 100644
--- a/include/linux/filelock.h
+++ b/include/linux/filelock.h
@@ -212,7 +212,14 @@ int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
 void locks_init_lease(struct file_lease *);
 void locks_free_lease(struct file_lease *fl);
 struct file_lease *locks_alloc_lease(void);
-int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
+
+#define LEASE_BREAK_LEASE		BIT(0)	// break leases and delegations
+#define LEASE_BREAK_DELEG		BIT(1)	// break delegations only
+#define LEASE_BREAK_LAYOUT		BIT(2)	// break layouts only
+#define LEASE_BREAK_NONBLOCK		BIT(3)	// non-blocking break
+#define LEASE_BREAK_OPEN_RDONLY		BIT(4)	// readonly open event
+
+int __break_lease(struct inode *inode, unsigned int flags);
 void lease_get_mtime(struct inode *, struct timespec64 *time);
 int generic_setlease(struct file *, int, struct file_lease **, void **priv);
 int kernel_setlease(struct file *, int, struct file_lease **, void **);
@@ -367,7 +374,7 @@ static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *f
 	return -ENOLCK;
 }
 
-static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
+static inline int __break_lease(struct inode *inode, unsigned int flags)
 {
 	return 0;
 }
@@ -428,6 +435,17 @@ static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
 }
 
 #ifdef CONFIG_FILE_LOCKING
+static inline unsigned int openmode_to_lease_flags(unsigned int mode)
+{
+	unsigned int flags = 0;
+
+	if ((mode & O_ACCMODE) == O_RDONLY)
+		flags |= LEASE_BREAK_OPEN_RDONLY;
+	if (mode & O_NONBLOCK)
+		flags |= LEASE_BREAK_NONBLOCK;
+	return flags;
+}
+
 static inline int break_lease(struct inode *inode, unsigned int mode)
 {
 	struct file_lock_context *flctx;
@@ -443,11 +461,11 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
 		return 0;
 	smp_mb();
 	if (!list_empty_careful(&flctx->flc_lease))
-		return __break_lease(inode, mode, FL_LEASE);
+		return __break_lease(inode, LEASE_BREAK_LEASE | openmode_to_lease_flags(mode));
 	return 0;
 }
 
-static inline int break_deleg(struct inode *inode, unsigned int mode)
+static inline int break_deleg(struct inode *inode, unsigned int flags)
 {
 	struct file_lock_context *flctx;
 
@@ -461,8 +479,10 @@ static inline int break_deleg(struct inode *inode, unsigned int mode)
 	if (!flctx)
 		return 0;
 	smp_mb();
-	if (!list_empty_careful(&flctx->flc_lease))
-		return __break_lease(inode, mode, FL_DELEG);
+	if (!list_empty_careful(&flctx->flc_lease)) {
+		flags |= LEASE_BREAK_DELEG;
+		return __break_lease(inode, flags);
+	}
 	return 0;
 }
 
@@ -470,7 +490,7 @@ static inline int try_break_deleg(struct inode *inode, struct inode **delegated_
 {
 	int ret;
 
-	ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
+	ret = break_deleg(inode, LEASE_BREAK_NONBLOCK);
 	if (ret == -EWOULDBLOCK && delegated_inode) {
 		*delegated_inode = inode;
 		ihold(inode);
@@ -482,7 +502,7 @@ static inline int break_deleg_wait(struct inode **delegated_inode)
 {
 	int ret;
 
-	ret = break_deleg(*delegated_inode, O_WRONLY);
+	ret = break_deleg(*delegated_inode, 0);
 	iput(*delegated_inode);
 	*delegated_inode = NULL;
 	return ret;
@@ -491,20 +511,24 @@ static inline int break_deleg_wait(struct inode **delegated_inode)
 static inline int break_layout(struct inode *inode, bool wait)
 {
 	smp_mb();
-	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
-		return __break_lease(inode,
-				wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,
-				FL_LAYOUT);
+	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) {
+		unsigned int flags = LEASE_BREAK_LAYOUT;
+
+		if (!wait)
+			flags |= LEASE_BREAK_NONBLOCK;
+
+		return __break_lease(inode, flags);
+	}
 	return 0;
 }
 
 #else /* !CONFIG_FILE_LOCKING */
-static inline int break_lease(struct inode *inode, unsigned int mode)
+static inline int break_lease(struct inode *inode, bool wait)
 {
 	return 0;
 }
 
-static inline int break_deleg(struct inode *inode, unsigned int mode)
+static inline int break_deleg(struct inode *inode, unsigned int flags)
 {
 	return 0;
 }
-- 
cgit v1.2.3


From 6976ed2dd0d59086d16d853ac9b21776be68aaad Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:44 -0500
Subject: filelock: add struct delegated_inode

The current API requires a pointer to an inode pointer. It's easy for
callers to get this wrong. Add a new delegated_inode structure and use
that to pass back any inode that needs to be waited on.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-3-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/attr.c                |  2 +-
 fs/namei.c               | 18 +++++++++---------
 fs/open.c                |  8 ++++----
 fs/posix_acl.c           |  8 ++++----
 fs/utimes.c              |  4 ++--
 fs/xattr.c               | 12 ++++++------
 include/linux/filelock.h | 36 +++++++++++++++++++++++++++---------
 include/linux/fs.h       |  9 +++++----
 include/linux/xattr.h    |  4 ++--
 9 files changed, 60 insertions(+), 41 deletions(-)

(limited to 'include')

diff --git a/fs/attr.c b/fs/attr.c
index 795f231d00e8..b9ec6b47bab2 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -415,7 +415,7 @@ EXPORT_SYMBOL(may_setattr);
  * performed on the raw inode simply pass @nop_mnt_idmap.
  */
 int notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
-		  struct iattr *attr, struct inode **delegated_inode)
+		  struct iattr *attr, struct delegated_inode *delegated_inode)
 {
 	struct inode *inode = dentry->d_inode;
 	umode_t mode = inode->i_mode;
diff --git a/fs/namei.c b/fs/namei.c
index 7377020a2cba..bf42f146f847 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4648,7 +4648,7 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
  * raw inode simply pass @nop_mnt_idmap.
  */
 int vfs_unlink(struct mnt_idmap *idmap, struct inode *dir,
-	       struct dentry *dentry, struct inode **delegated_inode)
+	       struct dentry *dentry, struct delegated_inode *delegated_inode)
 {
 	struct inode *target = dentry->d_inode;
 	int error = may_delete(idmap, dir, dentry, 0);
@@ -4706,7 +4706,7 @@ int do_unlinkat(int dfd, struct filename *name)
 	struct qstr last;
 	int type;
 	struct inode *inode = NULL;
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 	unsigned int lookup_flags = 0;
 retry:
 	error = filename_parentat(dfd, name, lookup_flags, &path, &last, &type);
@@ -4743,7 +4743,7 @@ exit3:
 	if (inode)
 		iput(inode);	/* truncate the inode here */
 	inode = NULL;
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
@@ -4892,7 +4892,7 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn
  */
 int vfs_link(struct dentry *old_dentry, struct mnt_idmap *idmap,
 	     struct inode *dir, struct dentry *new_dentry,
-	     struct inode **delegated_inode)
+	     struct delegated_inode *delegated_inode)
 {
 	struct inode *inode = old_dentry->d_inode;
 	unsigned max_links = dir->i_sb->s_max_links;
@@ -4968,7 +4968,7 @@ int do_linkat(int olddfd, struct filename *old, int newdfd,
 	struct mnt_idmap *idmap;
 	struct dentry *new_dentry;
 	struct path old_path, new_path;
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 	int how = 0;
 	int error;
 
@@ -5012,7 +5012,7 @@ retry:
 			 new_dentry, &delegated_inode);
 out_dput:
 	end_creating_path(&new_path, new_dentry);
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error) {
 			path_put(&old_path);
@@ -5098,7 +5098,7 @@ int vfs_rename(struct renamedata *rd)
 	struct inode *new_dir = d_inode(rd->new_parent);
 	struct dentry *old_dentry = rd->old_dentry;
 	struct dentry *new_dentry = rd->new_dentry;
-	struct inode **delegated_inode = rd->delegated_inode;
+	struct delegated_inode *delegated_inode = rd->delegated_inode;
 	unsigned int flags = rd->flags;
 	bool is_dir = d_is_dir(old_dentry);
 	struct inode *source = old_dentry->d_inode;
@@ -5261,7 +5261,7 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd,
 	struct path old_path, new_path;
 	struct qstr old_last, new_last;
 	int old_type, new_type;
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 	unsigned int lookup_flags = 0, target_flags =
 		LOOKUP_RENAME_TARGET | LOOKUP_CREATE;
 	bool should_retry = false;
@@ -5369,7 +5369,7 @@ exit4:
 exit3:
 	unlock_rename(new_path.dentry, old_path.dentry);
 exit_lock_rename:
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
diff --git a/fs/open.c b/fs/open.c
index 3d64372ecc67..fdaa6f08f6f4 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -631,7 +631,7 @@ out:
 int chmod_common(const struct path *path, umode_t mode)
 {
 	struct inode *inode = path->dentry->d_inode;
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 	struct iattr newattrs;
 	int error;
 
@@ -651,7 +651,7 @@ retry_deleg:
 			      &newattrs, &delegated_inode);
 out_unlock:
 	inode_unlock(inode);
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
@@ -756,7 +756,7 @@ int chown_common(const struct path *path, uid_t user, gid_t group)
 	struct mnt_idmap *idmap;
 	struct user_namespace *fs_userns;
 	struct inode *inode = path->dentry->d_inode;
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 	int error;
 	struct iattr newattrs;
 	kuid_t uid;
@@ -791,7 +791,7 @@ retry_deleg:
 		error = notify_change(idmap, path->dentry, &newattrs,
 				      &delegated_inode);
 	inode_unlock(inode);
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 4050942ab52f..768f027c1428 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -1091,7 +1091,7 @@ int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	int acl_type;
 	int error;
 	struct inode *inode = d_inode(dentry);
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 
 	acl_type = posix_acl_type(acl_name);
 	if (acl_type < 0)
@@ -1141,7 +1141,7 @@ retry_deleg:
 out_inode_unlock:
 	inode_unlock(inode);
 
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
@@ -1212,7 +1212,7 @@ int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	int acl_type;
 	int error;
 	struct inode *inode = d_inode(dentry);
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 
 	acl_type = posix_acl_type(acl_name);
 	if (acl_type < 0)
@@ -1249,7 +1249,7 @@ retry_deleg:
 out_inode_unlock:
 	inode_unlock(inode);
 
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
diff --git a/fs/utimes.c b/fs/utimes.c
index c7c7958e57b2..bf9f45bdef54 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -22,7 +22,7 @@ int vfs_utimes(const struct path *path, struct timespec64 *times)
 	int error;
 	struct iattr newattrs;
 	struct inode *inode = path->dentry->d_inode;
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 
 	if (times) {
 		if (!nsec_valid(times[0].tv_nsec) ||
@@ -66,7 +66,7 @@ retry_deleg:
 	error = notify_change(mnt_idmap(path->mnt), path->dentry, &newattrs,
 			      &delegated_inode);
 	inode_unlock(inode);
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
diff --git a/fs/xattr.c b/fs/xattr.c
index 8851a5ef34f5..32d445fb60aa 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -274,7 +274,7 @@ int __vfs_setxattr_noperm(struct mnt_idmap *idmap,
 int
 __vfs_setxattr_locked(struct mnt_idmap *idmap, struct dentry *dentry,
 		      const char *name, const void *value, size_t size,
-		      int flags, struct inode **delegated_inode)
+		      int flags, struct delegated_inode *delegated_inode)
 {
 	struct inode *inode = dentry->d_inode;
 	int error;
@@ -305,7 +305,7 @@ vfs_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	     const char *name, const void *value, size_t size, int flags)
 {
 	struct inode *inode = dentry->d_inode;
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 	const void  *orig_value = value;
 	int error;
 
@@ -322,7 +322,7 @@ retry_deleg:
 				      flags, &delegated_inode);
 	inode_unlock(inode);
 
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
@@ -533,7 +533,7 @@ EXPORT_SYMBOL(__vfs_removexattr);
 int
 __vfs_removexattr_locked(struct mnt_idmap *idmap,
 			 struct dentry *dentry, const char *name,
-			 struct inode **delegated_inode)
+			 struct delegated_inode *delegated_inode)
 {
 	struct inode *inode = dentry->d_inode;
 	int error;
@@ -567,7 +567,7 @@ vfs_removexattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		const char *name)
 {
 	struct inode *inode = dentry->d_inode;
-	struct inode *delegated_inode = NULL;
+	struct delegated_inode delegated_inode = { };
 	int error;
 
 retry_deleg:
@@ -576,7 +576,7 @@ retry_deleg:
 					 name, &delegated_inode);
 	inode_unlock(inode);
 
-	if (delegated_inode) {
+	if (is_delegated(&delegated_inode)) {
 		error = break_deleg_wait(&delegated_inode);
 		if (!error)
 			goto retry_deleg;
diff --git a/include/linux/filelock.h b/include/linux/filelock.h
index 47da6aa28d8d..208d108df2d7 100644
--- a/include/linux/filelock.h
+++ b/include/linux/filelock.h
@@ -486,25 +486,35 @@ static inline int break_deleg(struct inode *inode, unsigned int flags)
 	return 0;
 }
 
-static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
+struct delegated_inode {
+	struct inode *di_inode;
+};
+
+static inline bool is_delegated(struct delegated_inode *di)
+{
+	return di->di_inode;
+}
+
+static inline int try_break_deleg(struct inode *inode,
+				  struct delegated_inode *di)
 {
 	int ret;
 
 	ret = break_deleg(inode, LEASE_BREAK_NONBLOCK);
-	if (ret == -EWOULDBLOCK && delegated_inode) {
-		*delegated_inode = inode;
+	if (ret == -EWOULDBLOCK && di) {
+		di->di_inode = inode;
 		ihold(inode);
 	}
 	return ret;
 }
 
-static inline int break_deleg_wait(struct inode **delegated_inode)
+static inline int break_deleg_wait(struct delegated_inode *di)
 {
 	int ret;
 
-	ret = break_deleg(*delegated_inode, 0);
-	iput(*delegated_inode);
-	*delegated_inode = NULL;
+	ret = break_deleg(di->di_inode, 0);
+	iput(di->di_inode);
+	di->di_inode = NULL;
 	return ret;
 }
 
@@ -523,6 +533,13 @@ static inline int break_layout(struct inode *inode, bool wait)
 }
 
 #else /* !CONFIG_FILE_LOCKING */
+struct delegated_inode { };
+
+static inline bool is_delegated(struct delegated_inode *di)
+{
+	return false;
+}
+
 static inline int break_lease(struct inode *inode, bool wait)
 {
 	return 0;
@@ -533,12 +550,13 @@ static inline int break_deleg(struct inode *inode, unsigned int flags)
 	return 0;
 }
 
-static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
+static inline int try_break_deleg(struct inode *inode,
+				  struct delegated_inode *delegated_inode)
 {
 	return 0;
 }
 
-static inline int break_deleg_wait(struct inode **delegated_inode)
+static inline int break_deleg_wait(struct delegated_inode *delegated_inode)
 {
 	BUG();
 	return 0;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c895146c1444..909a88e3979d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -80,6 +80,7 @@ struct fs_context;
 struct fs_parameter_spec;
 struct file_kattr;
 struct iomap_ops;
+struct delegated_inode;
 
 extern void __init inode_init(void);
 extern void __init inode_init_early(void);
@@ -2119,10 +2120,10 @@ int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
 int vfs_symlink(struct mnt_idmap *, struct inode *,
 		struct dentry *, const char *);
 int vfs_link(struct dentry *, struct mnt_idmap *, struct inode *,
-	     struct dentry *, struct inode **);
+	     struct dentry *, struct delegated_inode *);
 int vfs_rmdir(struct mnt_idmap *, struct inode *, struct dentry *);
 int vfs_unlink(struct mnt_idmap *, struct inode *, struct dentry *,
-	       struct inode **);
+	       struct delegated_inode *);
 
 /**
  * struct renamedata - contains all information required for renaming
@@ -2140,7 +2141,7 @@ struct renamedata {
 	struct dentry *old_dentry;
 	struct dentry *new_parent;
 	struct dentry *new_dentry;
-	struct inode **delegated_inode;
+	struct delegated_inode *delegated_inode;
 	unsigned int flags;
 } __randomize_layout;
 
@@ -3071,7 +3072,7 @@ static inline int bmap(struct inode *inode,  sector_t *block)
 #endif
 
 int notify_change(struct mnt_idmap *, struct dentry *,
-		  struct iattr *, struct inode **);
+		  struct iattr *, struct delegated_inode *);
 int inode_permission(struct mnt_idmap *, struct inode *, int);
 int generic_permission(struct mnt_idmap *, struct inode *, int);
 static inline int file_permission(struct file *file, int mask)
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 86b0d47984a1..64e9afe7d647 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -85,12 +85,12 @@ int __vfs_setxattr_noperm(struct mnt_idmap *, struct dentry *,
 			  const char *, const void *, size_t, int);
 int __vfs_setxattr_locked(struct mnt_idmap *, struct dentry *,
 			  const char *, const void *, size_t, int,
-			  struct inode **);
+			  struct delegated_inode *);
 int vfs_setxattr(struct mnt_idmap *, struct dentry *, const char *,
 		 const void *, size_t, int);
 int __vfs_removexattr(struct mnt_idmap *, struct dentry *, const char *);
 int __vfs_removexattr_locked(struct mnt_idmap *, struct dentry *,
-			     const char *, struct inode **);
+			     const char *, struct delegated_inode *);
 int vfs_removexattr(struct mnt_idmap *, struct dentry *, const char *);
 
 ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
-- 
cgit v1.2.3


From e12d203b8c880061c0bf0339cad51e5851a33442 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:47 -0500
Subject: vfs: allow mkdir to wait for delegation break on parent

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. All of the existing
callers set that to NULL for now, except for do_mkdirat which will
properly block until the lease is gone.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-6-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 drivers/base/devtmpfs.c  |  2 +-
 fs/cachefiles/namei.c    |  2 +-
 fs/ecryptfs/inode.c      |  2 +-
 fs/init.c                |  2 +-
 fs/namei.c               | 24 ++++++++++++++++++------
 fs/nfsd/nfs4recover.c    |  2 +-
 fs/nfsd/vfs.c            |  2 +-
 fs/overlayfs/overlayfs.h |  2 +-
 fs/smb/server/vfs.c      |  2 +-
 fs/xfs/scrub/orphanage.c |  2 +-
 include/linux/fs.h       |  2 +-
 11 files changed, 28 insertions(+), 16 deletions(-)

(limited to 'include')

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 9d4e46ad8352..0e79621cb0f7 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -180,7 +180,7 @@ static int dev_mkdir(const char *name, umode_t mode)
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
-	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode);
+	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode, NULL);
 	if (!IS_ERR(dentry))
 		/* mark as kernel-created inode */
 		d_inode(dentry)->i_private = &thread;
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index d1edb2ac3837..50c0f9c76d1f 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -130,7 +130,7 @@ retry:
 			goto mkdir_error;
 		ret = cachefiles_inject_write_error();
 		if (ret == 0)
-			subdir = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700);
+			subdir = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), subdir, 0700, NULL);
 		else
 			subdir = ERR_PTR(ret);
 		if (IS_ERR(subdir)) {
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index ed1394da8d6b..35830b3144f8 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -508,7 +508,7 @@ static struct dentry *ecryptfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		goto out;
 
 	lower_dentry = vfs_mkdir(&nop_mnt_idmap, lower_dir,
-				 lower_dentry, mode);
+				 lower_dentry, mode, NULL);
 	rc = PTR_ERR(lower_dentry);
 	if (IS_ERR(lower_dentry))
 		goto out;
diff --git a/fs/init.c b/fs/init.c
index 07f592ccdba8..895f8a09a71a 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -233,7 +233,7 @@ int __init init_mkdir(const char *pathname, umode_t mode)
 	error = security_path_mkdir(&path, dentry, mode);
 	if (!error) {
 		dentry = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
-				  dentry, mode);
+				  dentry, mode, NULL);
 		if (IS_ERR(dentry))
 			error = PTR_ERR(dentry);
 	}
diff --git a/fs/namei.c b/fs/namei.c
index 5bcf3e93d350..76c0587d991f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4407,10 +4407,11 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
 
 /**
  * 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
- * @mode:	mode of the child directory
+ * @idmap:		idmap of the mount the inode was found from
+ * @dir:		inode of the parent directory
+ * @dentry:		dentry of the child directory
+ * @mode:		mode of the child directory
+ * @delegated_inode:	returns parent inode, if the inode is delegated.
  *
  * Create a directory.
  *
@@ -4427,7 +4428,8 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
  * In case of an error the dentry is dput() and an ERR_PTR() is returned.
  */
 struct dentry *vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
-			 struct dentry *dentry, umode_t mode)
+			 struct dentry *dentry, umode_t mode,
+			 struct delegated_inode *delegated_inode)
 {
 	int error;
 	unsigned max_links = dir->i_sb->s_max_links;
@@ -4450,6 +4452,10 @@ struct dentry *vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	if (max_links && dir->i_nlink >= max_links)
 		goto err;
 
+	error = try_break_deleg(dir, delegated_inode);
+	if (error)
+		goto err;
+
 	de = dir->i_op->mkdir(idmap, dir, dentry, mode);
 	error = PTR_ERR(de);
 	if (IS_ERR(de))
@@ -4473,6 +4479,7 @@ int do_mkdirat(int dfd, struct filename *name, umode_t mode)
 	struct path path;
 	int error;
 	unsigned int lookup_flags = LOOKUP_DIRECTORY;
+	struct delegated_inode delegated_inode = { };
 
 retry:
 	dentry = filename_create(dfd, name, &path, lookup_flags);
@@ -4484,11 +4491,16 @@ retry:
 			mode_strip_umask(path.dentry->d_inode, mode));
 	if (!error) {
 		dentry = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
-				  dentry, mode);
+				   dentry, mode, &delegated_inode);
 		if (IS_ERR(dentry))
 			error = PTR_ERR(dentry);
 	}
 	end_creating_path(&path, dentry);
+	if (is_delegated(&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 e2b9472e5c78..1f56834b2072 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -213,7 +213,7 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
 		 * as well be forgiving and just succeed silently.
 		 */
 		goto out_put;
-	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU);
+	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, 0700, NULL);
 	if (IS_ERR(dentry))
 		status = PTR_ERR(dentry);
 out_put:
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 9cb20d4aeab1..97aef140cbf5 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1558,7 +1558,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 			nfsd_check_ignore_resizing(iap);
 		break;
 	case S_IFDIR:
-		dchild = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode);
+		dchild = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode, NULL);
 		if (IS_ERR(dchild)) {
 			host_err = PTR_ERR(dchild);
 		} else if (d_is_negative(dchild)) {
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index c8fd5951fc5e..0f65f9a5d54d 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -248,7 +248,7 @@ static inline struct dentry *ovl_do_mkdir(struct ovl_fs *ofs,
 {
 	struct dentry *ret;
 
-	ret = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
+	ret = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, NULL);
 	pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(ret));
 	return ret;
 }
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index 891ed2dc2b73..3d2190f26623 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -230,7 +230,7 @@ int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)
 	idmap = mnt_idmap(path.mnt);
 	mode |= S_IFDIR;
 	d = dentry;
-	dentry = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode);
+	dentry = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode, NULL);
 	if (IS_ERR(dentry))
 		err = PTR_ERR(dentry);
 	else if (d_is_negative(dentry))
diff --git a/fs/xfs/scrub/orphanage.c b/fs/xfs/scrub/orphanage.c
index 9c12cb844231..91c9d07b97f3 100644
--- a/fs/xfs/scrub/orphanage.c
+++ b/fs/xfs/scrub/orphanage.c
@@ -167,7 +167,7 @@ xrep_orphanage_create(
 	 */
 	if (d_really_is_negative(orphanage_dentry)) {
 		orphanage_dentry = vfs_mkdir(&nop_mnt_idmap, root_inode,
-					     orphanage_dentry, 0750);
+					     orphanage_dentry, 0750, NULL);
 		error = PTR_ERR(orphanage_dentry);
 		if (IS_ERR(orphanage_dentry))
 			goto out_unlock_root;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 909a88e3979d..20bb4c8a4e8e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2114,7 +2114,7 @@ bool inode_owner_or_capable(struct mnt_idmap *idmap,
 int vfs_create(struct mnt_idmap *, struct inode *,
 	       struct dentry *, umode_t, bool);
 struct dentry *vfs_mkdir(struct mnt_idmap *, struct inode *,
-			 struct dentry *, umode_t);
+			 struct dentry *, umode_t, struct delegated_inode *);
 int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
               umode_t, dev_t);
 int vfs_symlink(struct mnt_idmap *, struct inode *,
-- 
cgit v1.2.3


From 4fa76319cd0cc97ca54ff71c94814dc5b1983ad2 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:48 -0500
Subject: vfs: allow rmdir to wait for delegation break on parent

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 delegated_inode struct to vfs_rmdir() and populate that
pointer with the parent inode if it's non-NULL. Most existing in-kernel
callers pass in a NULL pointer.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-7-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 drivers/base/devtmpfs.c  |  2 +-
 fs/ecryptfs/inode.c      |  2 +-
 fs/namei.c               | 22 +++++++++++++++++-----
 fs/nfsd/nfs4recover.c    |  4 ++--
 fs/nfsd/vfs.c            |  2 +-
 fs/overlayfs/overlayfs.h |  2 +-
 fs/smb/server/vfs.c      |  4 ++--
 include/linux/fs.h       |  3 ++-
 8 files changed, 27 insertions(+), 14 deletions(-)

(limited to 'include')

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 0e79621cb0f7..104025104ef7 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -261,7 +261,7 @@ static int dev_rmdir(const char *name)
 		return PTR_ERR(dentry);
 	if (d_inode(dentry)->i_private == &thread)
 		err = vfs_rmdir(&nop_mnt_idmap, d_inode(parent.dentry),
-				dentry);
+				dentry, NULL);
 	else
 		err = -EPERM;
 
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 35830b3144f8..88631291b325 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -540,7 +540,7 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
 		if (d_unhashed(lower_dentry))
 			rc = -EINVAL;
 		else
-			rc = vfs_rmdir(&nop_mnt_idmap, lower_dir, lower_dentry);
+			rc = vfs_rmdir(&nop_mnt_idmap, lower_dir, lower_dentry, NULL);
 	}
 	if (!rc) {
 		clear_nlink(d_inode(dentry));
diff --git a/fs/namei.c b/fs/namei.c
index 76c0587d991f..9e0393a92091 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4522,9 +4522,10 @@ SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
 
 /**
  * vfs_rmdir - remove directory
- * @idmap:	idmap of the mount the inode was found from
- * @dir:	inode of the parent directory
- * @dentry:	dentry of the child directory
+ * @idmap:		idmap of the mount the inode was found from
+ * @dir:		inode of the parent directory
+ * @dentry:		dentry of the child directory
+ * @delegated_inode:	returns parent inode, if it's delegated.
  *
  * Remove a directory.
  *
@@ -4535,7 +4536,7 @@ SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
  * raw inode simply pass @nop_mnt_idmap.
  */
 int vfs_rmdir(struct mnt_idmap *idmap, struct inode *dir,
-		     struct dentry *dentry)
+	      struct dentry *dentry, struct delegated_inode *delegated_inode)
 {
 	int error = may_delete(idmap, dir, dentry, 1);
 
@@ -4557,6 +4558,10 @@ int vfs_rmdir(struct mnt_idmap *idmap, struct inode *dir,
 	if (error)
 		goto out;
 
+	error = try_break_deleg(dir, delegated_inode);
+	if (error)
+		goto out;
+
 	error = dir->i_op->rmdir(dir, dentry);
 	if (error)
 		goto out;
@@ -4583,6 +4588,7 @@ int do_rmdir(int dfd, struct filename *name)
 	struct qstr last;
 	int type;
 	unsigned int lookup_flags = 0;
+	struct delegated_inode delegated_inode = { };
 retry:
 	error = filename_parentat(dfd, name, lookup_flags, &path, &last, &type);
 	if (error)
@@ -4612,7 +4618,8 @@ retry:
 	error = security_path_rmdir(&path, dentry);
 	if (error)
 		goto exit4;
-	error = vfs_rmdir(mnt_idmap(path.mnt), path.dentry->d_inode, dentry);
+	error = vfs_rmdir(mnt_idmap(path.mnt), path.dentry->d_inode,
+			  dentry, &delegated_inode);
 exit4:
 	dput(dentry);
 exit3:
@@ -4620,6 +4627,11 @@ exit3:
 	mnt_drop_write(path.mnt);
 exit2:
 	path_put(&path);
+	if (is_delegated(&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 1f56834b2072..30bae93931d9 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -337,7 +337,7 @@ nfsd4_unlink_clid_dir(char *name, struct nfsd_net *nn)
 	status = -ENOENT;
 	if (d_really_is_negative(dentry))
 		goto out;
-	status = vfs_rmdir(&nop_mnt_idmap, d_inode(dir), dentry);
+	status = vfs_rmdir(&nop_mnt_idmap, d_inode(dir), dentry, NULL);
 out:
 	dput(dentry);
 out_unlock:
@@ -427,7 +427,7 @@ purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 	if (nfs4_has_reclaimed_state(name, nn))
 		goto out_free;
 
-	status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child);
+	status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child, NULL);
 	if (status)
 		printk("failed to remove client recovery directory %pd\n",
 				child);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 97aef140cbf5..c400ea94ff2e 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -2108,7 +2108,7 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 				break;
 		}
 	} else {
-		host_err = vfs_rmdir(&nop_mnt_idmap, dirp, rdentry);
+		host_err = vfs_rmdir(&nop_mnt_idmap, dirp, rdentry, NULL);
 	}
 	fh_fill_post_attrs(fhp);
 
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 0f65f9a5d54d..d215d7349489 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -206,7 +206,7 @@ static inline int ovl_do_notify_change(struct ovl_fs *ofs,
 static inline int ovl_do_rmdir(struct ovl_fs *ofs,
 			       struct inode *dir, struct dentry *dentry)
 {
-	int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry);
+	int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL);
 
 	pr_debug("rmdir(%pd2) = %i\n", dentry, err);
 	return err;
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index 3d2190f26623..c5f0f3170d58 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -609,7 +609,7 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path)
 
 	idmap = mnt_idmap(path->mnt);
 	if (S_ISDIR(d_inode(path->dentry)->i_mode)) {
-		err = vfs_rmdir(idmap, d_inode(parent), path->dentry);
+		err = vfs_rmdir(idmap, d_inode(parent), path->dentry, NULL);
 		if (err && err != -ENOTEMPTY)
 			ksmbd_debug(VFS, "rmdir failed, err %d\n", err);
 	} else {
@@ -1090,7 +1090,7 @@ int ksmbd_vfs_unlink(struct file *filp)
 	dget(dentry);
 
 	if (S_ISDIR(d_inode(dentry)->i_mode))
-		err = vfs_rmdir(idmap, d_inode(dir), dentry);
+		err = vfs_rmdir(idmap, d_inode(dir), dentry, NULL);
 	else
 		err = vfs_unlink(idmap, d_inode(dir), dentry, NULL);
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 20bb4c8a4e8e..12873214e1c7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2121,7 +2121,8 @@ int vfs_symlink(struct mnt_idmap *, struct inode *,
 		struct dentry *, const char *);
 int vfs_link(struct dentry *, struct mnt_idmap *, struct inode *,
 	     struct dentry *, struct delegated_inode *);
-int vfs_rmdir(struct mnt_idmap *, struct inode *, struct dentry *);
+int vfs_rmdir(struct mnt_idmap *, struct inode *, struct dentry *,
+	      struct delegated_inode *);
 int vfs_unlink(struct mnt_idmap *, struct inode *, struct dentry *,
 	       struct delegated_inode *);
 
-- 
cgit v1.2.3


From 85bbffcad7307e2ca6136be657cc21b0e1c42241 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:50 -0500
Subject: vfs: clean up argument list for vfs_create()

As Neil points out:

"I would be in favour of dropping the "dir" arg because it is always
d_inode(dentry->d_parent) which is stable."

...and...

"Also *every* caller of vfs_create() passes ".excl = true".  So maybe we
don't need that arg at all."

Drop both arguments from vfs_create() and fix up the callers.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-9-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/ecryptfs/inode.c      |  3 +--
 fs/namei.c               | 11 ++++-------
 fs/nfsd/nfs3proc.c       |  2 +-
 fs/nfsd/vfs.c            |  3 +--
 fs/open.c                |  4 +---
 fs/overlayfs/overlayfs.h |  2 +-
 fs/smb/server/vfs.c      |  3 +--
 include/linux/fs.h       |  3 +--
 8 files changed, 11 insertions(+), 20 deletions(-)

(limited to 'include')

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 88631291b325..d109e3763a88 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -188,8 +188,7 @@ ecryptfs_do_create(struct inode *directory_inode,
 
 	rc = lock_parent(ecryptfs_dentry, &lower_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_create(&nop_mnt_idmap, lower_dir,
-				lower_dentry, mode, true);
+		rc = vfs_create(&nop_mnt_idmap, lower_dentry, mode);
 	if (rc) {
 		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
 		       "rc = [%d]\n", __func__, rc);
diff --git a/fs/namei.c b/fs/namei.c
index f439429bdfa2..9586c6aba6ea 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3461,10 +3461,8 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
 /**
  * vfs_create - create new file
  * @idmap:	idmap of the mount the inode was found from
- * @dir:	inode of the parent directory
  * @dentry:	dentry of the child file
  * @mode:	mode of the child file
- * @want_excl:	whether the file must not yet exist
  *
  * Create a new file.
  *
@@ -3474,9 +3472,9 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
  * On non-idmapped mounts or if permission checking is to be performed on the
  * raw inode simply pass @nop_mnt_idmap.
  */
-int vfs_create(struct mnt_idmap *idmap, struct inode *dir,
-	       struct dentry *dentry, umode_t mode, bool want_excl)
+int vfs_create(struct mnt_idmap *idmap, struct dentry *dentry, umode_t mode)
 {
+	struct inode *dir = d_inode(dentry->d_parent);
 	int error;
 
 	error = may_create(idmap, dir, dentry);
@@ -3490,7 +3488,7 @@ int vfs_create(struct mnt_idmap *idmap, struct inode *dir,
 	error = security_inode_create(dir, dentry, mode);
 	if (error)
 		return error;
-	error = dir->i_op->create(idmap, dir, dentry, mode, want_excl);
+	error = dir->i_op->create(idmap, dir, dentry, mode, true);
 	if (!error)
 		fsnotify_create(dir, dentry);
 	return error;
@@ -4383,8 +4381,7 @@ retry:
 	idmap = mnt_idmap(path.mnt);
 	switch (mode & S_IFMT) {
 		case 0: case S_IFREG:
-			error = vfs_create(idmap, path.dentry->d_inode,
-					   dentry, mode, true);
+			error = vfs_create(idmap, dentry, mode);
 			if (!error)
 				security_path_post_mknod(idmap, dentry);
 			break;
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index b6d03e1ef5f7..30ea7ffa2aff 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -344,7 +344,7 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	status = fh_fill_pre_attrs(fhp);
 	if (status != nfs_ok)
 		goto out;
-	host_err = vfs_create(&nop_mnt_idmap, inode, child, iap->ia_mode, true);
+	host_err = vfs_create(&nop_mnt_idmap, child, iap->ia_mode);
 	if (host_err < 0) {
 		status = nfserrno(host_err);
 		goto out;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index c400ea94ff2e..464fd54675f3 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1552,8 +1552,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err = 0;
 	switch (type) {
 	case S_IFREG:
-		host_err = vfs_create(&nop_mnt_idmap, dirp, dchild,
-				      iap->ia_mode, true);
+		host_err = vfs_create(&nop_mnt_idmap, dchild, iap->ia_mode);
 		if (!host_err)
 			nfsd_check_ignore_resizing(iap);
 		break;
diff --git a/fs/open.c b/fs/open.c
index fdaa6f08f6f4..e440f58e3ce8 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1171,9 +1171,7 @@ struct file *dentry_create(const struct path *path, int flags, umode_t mode,
 	if (IS_ERR(f))
 		return f;
 
-	error = vfs_create(mnt_idmap(path->mnt),
-			   d_inode(path->dentry->d_parent),
-			   path->dentry, mode, true);
+	error = vfs_create(mnt_idmap(path->mnt), path->dentry, mode);
 	if (!error)
 		error = vfs_open(path, f);
 
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index d215d7349489..2bdc434941eb 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -235,7 +235,7 @@ static inline int ovl_do_create(struct ovl_fs *ofs,
 				struct inode *dir, struct dentry *dentry,
 				umode_t mode)
 {
-	int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true);
+	int err = vfs_create(ovl_upper_mnt_idmap(ofs), dentry, mode);
 
 	pr_debug("create(%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 c5f0f3170d58..83ece2de4b23 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -188,8 +188,7 @@ int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode)
 	}
 
 	mode |= S_IFREG;
-	err = vfs_create(mnt_idmap(path.mnt), d_inode(path.dentry),
-			 dentry, mode, true);
+	err = vfs_create(mnt_idmap(path.mnt), dentry, mode);
 	if (!err) {
 		ksmbd_vfs_inherit_owner(work, d_inode(path.dentry),
 					d_inode(dentry));
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 12873214e1c7..21876ef1fec9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2111,8 +2111,7 @@ bool inode_owner_or_capable(struct mnt_idmap *idmap,
 /*
  * VFS helper functions..
  */
-int vfs_create(struct mnt_idmap *, struct inode *,
-	       struct dentry *, umode_t, bool);
+int vfs_create(struct mnt_idmap *, struct dentry *, umode_t);
 struct dentry *vfs_mkdir(struct mnt_idmap *, struct inode *,
 			 struct dentry *, umode_t, struct delegated_inode *);
 int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
-- 
cgit v1.2.3


From c826229c6a82fe1fe7b7752692f87a881eb4b545 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:51 -0500
Subject: vfs: make vfs_create break delegations on parent directory

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 delegated_inode parameter to vfs_create. Most callers are
converted to pass in NULL, but do_mknodat() is changed to wait for a
delegation break if there is one.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-10-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/ecryptfs/inode.c      |  2 +-
 fs/namei.c               | 15 +++++++++++++--
 fs/nfsd/nfs3proc.c       |  2 +-
 fs/nfsd/vfs.c            |  2 +-
 fs/open.c                |  2 +-
 fs/overlayfs/overlayfs.h |  2 +-
 fs/smb/server/vfs.c      |  2 +-
 include/linux/fs.h       |  3 ++-
 8 files changed, 21 insertions(+), 9 deletions(-)

(limited to 'include')

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index d109e3763a88..3341f00dd087 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -188,7 +188,7 @@ ecryptfs_do_create(struct inode *directory_inode,
 
 	rc = lock_parent(ecryptfs_dentry, &lower_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_create(&nop_mnt_idmap, lower_dentry, mode);
+		rc = vfs_create(&nop_mnt_idmap, lower_dentry, mode, NULL);
 	if (rc) {
 		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
 		       "rc = [%d]\n", __func__, rc);
diff --git a/fs/namei.c b/fs/namei.c
index 9586c6aba6ea..b20f053374a5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3463,6 +3463,7 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
  * @idmap:	idmap of the mount the inode was found from
  * @dentry:	dentry of the child file
  * @mode:	mode of the child file
+ * @di:		returns parent inode, if the inode is delegated.
  *
  * Create a new file.
  *
@@ -3472,7 +3473,8 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
  * On non-idmapped mounts or if permission checking is to be performed on the
  * raw inode simply pass @nop_mnt_idmap.
  */
-int vfs_create(struct mnt_idmap *idmap, struct dentry *dentry, umode_t mode)
+int vfs_create(struct mnt_idmap *idmap, struct dentry *dentry, umode_t mode,
+	       struct delegated_inode *di)
 {
 	struct inode *dir = d_inode(dentry->d_parent);
 	int error;
@@ -3486,6 +3488,9 @@ int vfs_create(struct mnt_idmap *idmap, struct dentry *dentry, umode_t mode)
 
 	mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
 	error = security_inode_create(dir, dentry, mode);
+	if (error)
+		return error;
+	error = try_break_deleg(dir, di);
 	if (error)
 		return error;
 	error = dir->i_op->create(idmap, dir, dentry, mode, true);
@@ -4358,6 +4363,7 @@ static int may_mknod(umode_t mode)
 static int do_mknodat(int dfd, struct filename *name, umode_t mode,
 		unsigned int dev)
 {
+	struct delegated_inode di = { };
 	struct mnt_idmap *idmap;
 	struct dentry *dentry;
 	struct path path;
@@ -4381,7 +4387,7 @@ retry:
 	idmap = mnt_idmap(path.mnt);
 	switch (mode & S_IFMT) {
 		case 0: case S_IFREG:
-			error = vfs_create(idmap, dentry, mode);
+			error = vfs_create(idmap, dentry, mode, &di);
 			if (!error)
 				security_path_post_mknod(idmap, dentry);
 			break;
@@ -4396,6 +4402,11 @@ retry:
 	}
 out2:
 	end_creating_path(&path, dentry);
+	if (is_delegated(&di)) {
+		error = break_deleg_wait(&di);
+		if (!error)
+			goto retry;
+	}
 	if (retry_estale(error, lookup_flags)) {
 		lookup_flags |= LOOKUP_REVAL;
 		goto retry;
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 30ea7ffa2aff..2cb972b5ed99 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -344,7 +344,7 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	status = fh_fill_pre_attrs(fhp);
 	if (status != nfs_ok)
 		goto out;
-	host_err = vfs_create(&nop_mnt_idmap, child, iap->ia_mode);
+	host_err = vfs_create(&nop_mnt_idmap, child, iap->ia_mode, NULL);
 	if (host_err < 0) {
 		status = nfserrno(host_err);
 		goto out;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 464fd54675f3..de5f46f8c6d3 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1552,7 +1552,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err = 0;
 	switch (type) {
 	case S_IFREG:
-		host_err = vfs_create(&nop_mnt_idmap, dchild, iap->ia_mode);
+		host_err = vfs_create(&nop_mnt_idmap, dchild, iap->ia_mode, NULL);
 		if (!host_err)
 			nfsd_check_ignore_resizing(iap);
 		break;
diff --git a/fs/open.c b/fs/open.c
index e440f58e3ce8..92cf2e11781b 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1171,7 +1171,7 @@ struct file *dentry_create(const struct path *path, int flags, umode_t mode,
 	if (IS_ERR(f))
 		return f;
 
-	error = vfs_create(mnt_idmap(path->mnt), path->dentry, mode);
+	error = vfs_create(mnt_idmap(path->mnt), path->dentry, mode, NULL);
 	if (!error)
 		error = vfs_open(path, f);
 
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 2bdc434941eb..e30441cc9c63 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -235,7 +235,7 @@ static inline int ovl_do_create(struct ovl_fs *ofs,
 				struct inode *dir, struct dentry *dentry,
 				umode_t mode)
 {
-	int err = vfs_create(ovl_upper_mnt_idmap(ofs), dentry, mode);
+	int err = vfs_create(ovl_upper_mnt_idmap(ofs), dentry, mode, NULL);
 
 	pr_debug("create(%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 83ece2de4b23..3747851b61c8 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -188,7 +188,7 @@ int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode)
 	}
 
 	mode |= S_IFREG;
-	err = vfs_create(mnt_idmap(path.mnt), dentry, mode);
+	err = vfs_create(mnt_idmap(path.mnt), dentry, mode, NULL);
 	if (!err) {
 		ksmbd_vfs_inherit_owner(work, d_inode(path.dentry),
 					d_inode(dentry));
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 21876ef1fec9..83b05aec4e10 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2111,7 +2111,8 @@ bool inode_owner_or_capable(struct mnt_idmap *idmap,
 /*
  * VFS helper functions..
  */
-int vfs_create(struct mnt_idmap *, struct dentry *, umode_t);
+int vfs_create(struct mnt_idmap *, struct dentry *, umode_t,
+	       struct delegated_inode *);
 struct dentry *vfs_mkdir(struct mnt_idmap *, struct inode *,
 			 struct dentry *, umode_t, struct delegated_inode *);
 int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
-- 
cgit v1.2.3


From e8960c1b2ee9ba75d65492b8e90e851d11e5f215 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:52 -0500
Subject: vfs: make vfs_mknod break delegations on parent directory

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 pointer to vfs_mknod() and have the
appropriate callers wait when there is an outstanding delegation. All
other callers just set the pointer to NULL.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-11-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 drivers/base/devtmpfs.c  |  2 +-
 fs/ecryptfs/inode.c      |  2 +-
 fs/init.c                |  2 +-
 fs/namei.c               | 23 +++++++++++++++--------
 fs/nfsd/vfs.c            |  2 +-
 fs/overlayfs/overlayfs.h |  2 +-
 include/linux/fs.h       |  4 ++--
 net/unix/af_unix.c       |  2 +-
 8 files changed, 23 insertions(+), 16 deletions(-)

(limited to 'include')

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 104025104ef7..2f576ecf1832 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -231,7 +231,7 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid,
 		return PTR_ERR(dentry);
 
 	err = vfs_mknod(&nop_mnt_idmap, d_inode(path.dentry), dentry, mode,
-			dev->devt);
+			dev->devt, NULL);
 	if (!err) {
 		struct iattr newattrs;
 
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 3341f00dd087..83f06452476d 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -564,7 +564,7 @@ ecryptfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
 	if (!rc)
 		rc = vfs_mknod(&nop_mnt_idmap, lower_dir,
-			       lower_dentry, mode, dev);
+			       lower_dentry, mode, dev, 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 895f8a09a71a..4f02260dd65b 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -157,7 +157,7 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
 	error = security_path_mknod(&path, dentry, mode, dev);
 	if (!error)
 		error = vfs_mknod(mnt_idmap(path.mnt), path.dentry->d_inode,
-				  dentry, mode, new_decode_dev(dev));
+				  dentry, mode, new_decode_dev(dev), NULL);
 	end_creating_path(&path, dentry);
 	return error;
 }
diff --git a/fs/namei.c b/fs/namei.c
index b20f053374a5..e9616134390f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4295,13 +4295,15 @@ inline struct dentry *start_creating_user_path(
 }
 EXPORT_SYMBOL(start_creating_user_path);
 
+
 /**
  * vfs_mknod - create device node or file
- * @idmap:	idmap of the mount the inode was found from
- * @dir:	inode of the parent directory
- * @dentry:	dentry of the child device node
- * @mode:	mode of the child device node
- * @dev:	device number of device to create
+ * @idmap:		idmap of the mount the inode was found from
+ * @dir:		inode of the parent directory
+ * @dentry:		dentry of the child device node
+ * @mode:		mode of the child device node
+ * @dev:		device number of device to create
+ * @delegated_inode:	returns parent inode, if the inode is delegated.
  *
  * Create a device node or file.
  *
@@ -4312,7 +4314,8 @@ EXPORT_SYMBOL(start_creating_user_path);
  * raw inode simply pass @nop_mnt_idmap.
  */
 int vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
-	      struct dentry *dentry, umode_t mode, dev_t dev)
+	      struct dentry *dentry, umode_t mode, dev_t dev,
+	      struct delegated_inode *delegated_inode)
 {
 	bool is_whiteout = S_ISCHR(mode) && dev == WHITEOUT_DEV;
 	int error = may_create(idmap, dir, dentry);
@@ -4336,6 +4339,10 @@ int vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	if (error)
 		return error;
 
+	error = try_break_deleg(dir, delegated_inode);
+	if (error)
+		return error;
+
 	error = dir->i_op->mknod(idmap, dir, dentry, mode, dev);
 	if (!error)
 		fsnotify_create(dir, dentry);
@@ -4393,11 +4400,11 @@ retry:
 			break;
 		case S_IFCHR: case S_IFBLK:
 			error = vfs_mknod(idmap, path.dentry->d_inode,
-					  dentry, mode, new_decode_dev(dev));
+					  dentry, mode, new_decode_dev(dev), &di);
 			break;
 		case S_IFIFO: case S_IFSOCK:
 			error = vfs_mknod(idmap, path.dentry->d_inode,
-					  dentry, mode, 0);
+					  dentry, mode, 0, &di);
 			break;
 	}
 out2:
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index de5f46f8c6d3..6684935007b1 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1573,7 +1573,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	case S_IFIFO:
 	case S_IFSOCK:
 		host_err = vfs_mknod(&nop_mnt_idmap, dirp, dchild,
-				     iap->ia_mode, rdev);
+				     iap->ia_mode, rdev, NULL);
 		break;
 	default:
 		printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index e30441cc9c63..afd95721f76e 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -257,7 +257,7 @@ static inline int ovl_do_mknod(struct ovl_fs *ofs,
 			       struct inode *dir, struct dentry *dentry,
 			       umode_t mode, dev_t dev)
 {
-	int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev);
+	int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev, NULL);
 
 	pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
 	return err;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 83b05aec4e10..1a5d86cfafaa 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2116,7 +2116,7 @@ int vfs_create(struct mnt_idmap *, struct dentry *, umode_t,
 struct dentry *vfs_mkdir(struct mnt_idmap *, struct inode *,
 			 struct dentry *, umode_t, struct delegated_inode *);
 int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
-              umode_t, dev_t);
+	      umode_t, dev_t, struct delegated_inode *);
 int vfs_symlink(struct mnt_idmap *, struct inode *,
 		struct dentry *, const char *);
 int vfs_link(struct dentry *, struct mnt_idmap *, struct inode *,
@@ -2152,7 +2152,7 @@ static inline int vfs_whiteout(struct mnt_idmap *idmap,
 			       struct inode *dir, struct dentry *dentry)
 {
 	return vfs_mknod(idmap, dir, dentry, S_IFCHR | WHITEOUT_MODE,
-			 WHITEOUT_DEV);
+			 WHITEOUT_DEV, NULL);
 }
 
 struct file *kernel_tmpfile_open(struct mnt_idmap *idmap,
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 768098dec231..db1fd8d6a84c 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1399,7 +1399,7 @@ static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr,
 	idmap = mnt_idmap(parent.mnt);
 	err = security_path_mknod(&parent, dentry, mode, 0);
 	if (!err)
-		err = vfs_mknod(idmap, d_inode(parent.dentry), dentry, mode, 0);
+		err = vfs_mknod(idmap, d_inode(parent.dentry), dentry, mode, 0, NULL);
 	if (err)
 		goto out_path;
 	err = mutex_lock_interruptible(&u->bindlock);
-- 
cgit v1.2.3


From 92bf53577f01aad988f7f39f69163b41f94cfb7d Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:53 -0500
Subject: vfs: make vfs_symlink break delegations on parent dir

In order to add directory delegation support, we must break delegations
on the parent on any change to the directory.

Add a delegated_inode parameter to vfs_symlink() and have it break the
delegation. do_symlinkat() can then wait on the delegation break before
proceeding.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-12-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/ecryptfs/inode.c      |  2 +-
 fs/init.c                |  2 +-
 fs/namei.c               | 16 ++++++++++++++--
 fs/nfsd/vfs.c            |  2 +-
 fs/overlayfs/overlayfs.h |  2 +-
 include/linux/fs.h       |  2 +-
 6 files changed, 19 insertions(+), 7 deletions(-)

(limited to 'include')

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 83f06452476d..ba15e7359dfa 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -479,7 +479,7 @@ static int ecryptfs_symlink(struct mnt_idmap *idmap,
 	if (rc)
 		goto out_lock;
 	rc = vfs_symlink(&nop_mnt_idmap, lower_dir, lower_dentry,
-			 encoded_symname);
+			 encoded_symname, NULL);
 	kfree(encoded_symname);
 	if (rc || d_really_is_negative(lower_dentry))
 		goto out_lock;
diff --git a/fs/init.c b/fs/init.c
index 4f02260dd65b..e0f5429c0a49 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -209,7 +209,7 @@ int __init init_symlink(const char *oldname, const char *newname)
 	error = security_path_symlink(&path, dentry, oldname);
 	if (!error)
 		error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,
-				    dentry, oldname);
+				    dentry, oldname, NULL);
 	end_creating_path(&path, dentry);
 	return error;
 }
diff --git a/fs/namei.c b/fs/namei.c
index e9616134390f..d5ab28947b2b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4845,6 +4845,7 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname)
  * @dir:	inode of the parent directory
  * @dentry:	dentry of the child symlink file
  * @oldname:	name of the file to link to
+ * @delegated_inode: returns victim inode, if the inode is delegated.
  *
  * Create a symlink.
  *
@@ -4855,7 +4856,8 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname)
  * raw inode simply pass @nop_mnt_idmap.
  */
 int vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
-		struct dentry *dentry, const char *oldname)
+		struct dentry *dentry, const char *oldname,
+		struct delegated_inode *delegated_inode)
 {
 	int error;
 
@@ -4870,6 +4872,10 @@ int vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	if (error)
 		return error;
 
+	error = try_break_deleg(dir, delegated_inode);
+	if (error)
+		return error;
+
 	error = dir->i_op->symlink(idmap, dir, dentry, oldname);
 	if (!error)
 		fsnotify_create(dir, dentry);
@@ -4883,6 +4889,7 @@ int do_symlinkat(struct filename *from, int newdfd, struct filename *to)
 	struct dentry *dentry;
 	struct path path;
 	unsigned int lookup_flags = 0;
+	struct delegated_inode delegated_inode = { };
 
 	if (IS_ERR(from)) {
 		error = PTR_ERR(from);
@@ -4897,8 +4904,13 @@ retry:
 	error = security_path_symlink(&path, dentry, from->name);
 	if (!error)
 		error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,
-				    dentry, from->name);
+				    dentry, from->name, &delegated_inode);
 	end_creating_path(&path, dentry);
+	if (is_delegated(&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/vfs.c b/fs/nfsd/vfs.c
index 6684935007b1..28710da4cce7 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1742,7 +1742,7 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err = fh_fill_pre_attrs(fhp);
 	if (err != nfs_ok)
 		goto out_unlock;
-	host_err = vfs_symlink(&nop_mnt_idmap, d_inode(dentry), dnew, path);
+	host_err = vfs_symlink(&nop_mnt_idmap, d_inode(dentry), dnew, path, NULL);
 	err = nfserrno(host_err);
 	cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
 	if (!err)
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index afd95721f76e..5065961bd370 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -267,7 +267,7 @@ static inline int ovl_do_symlink(struct ovl_fs *ofs,
 				 struct inode *dir, struct dentry *dentry,
 				 const char *oldname)
 {
-	int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname);
+	int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname, NULL);
 
 	pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
 	return err;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1a5d86cfafaa..64323e618724 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2118,7 +2118,7 @@ struct dentry *vfs_mkdir(struct mnt_idmap *, struct inode *,
 int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
 	      umode_t, dev_t, struct delegated_inode *);
 int vfs_symlink(struct mnt_idmap *, struct inode *,
-		struct dentry *, const char *);
+		struct dentry *, const char *, struct delegated_inode *);
 int vfs_link(struct dentry *, struct mnt_idmap *, struct inode *,
 	     struct dentry *, struct delegated_inode *);
 int vfs_rmdir(struct mnt_idmap *, struct inode *, struct dentry *,
-- 
cgit v1.2.3


From 1602bad16d7df82faca6d7c70821117684a66f49 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Tue, 11 Nov 2025 09:12:58 -0500
Subject: vfs: expose delegation support to userland

Now that support for recallable directory delegations is available,
expose this functionality to userland with new F_SETDELEG and F_GETDELEG
commands for fcntl().

Note that this also allows userland to request a FL_DELEG type lease on
files too. Userland applications that do will get signalled when there
are metadata changes in addition to just data changes (which is a
limitation of FL_LEASE leases).

These commands accept a new "struct delegation" argument that contains a
flags field for future expansion.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-17-52f3feebb2f2@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/fcntl.c                 | 13 +++++++++++++
 fs/locks.c                 | 45 ++++++++++++++++++++++++++++++++++++++++-----
 include/linux/filelock.h   | 12 ++++++++++++
 include/uapi/linux/fcntl.h | 11 +++++++++++
 4 files changed, 76 insertions(+), 5 deletions(-)

(limited to 'include')

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 72f8433d9109..f93dbca08435 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -445,6 +445,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
 		struct file *filp)
 {
 	void __user *argp = (void __user *)arg;
+	struct delegation deleg;
 	int argi = (int)arg;
 	struct flock flock;
 	long err = -EINVAL;
@@ -550,6 +551,18 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
 	case F_SET_RW_HINT:
 		err = fcntl_set_rw_hint(filp, arg);
 		break;
+	case F_GETDELEG:
+		if (copy_from_user(&deleg, argp, sizeof(deleg)))
+			return -EFAULT;
+		err = fcntl_getdeleg(filp, &deleg);
+		if (!err && copy_to_user(argp, &deleg, sizeof(deleg)))
+			return -EFAULT;
+		break;
+	case F_SETDELEG:
+		if (copy_from_user(&deleg, argp, sizeof(deleg)))
+			return -EFAULT;
+		err = fcntl_setdeleg(fd, filp, &deleg);
+		break;
 	default:
 		break;
 	}
diff --git a/fs/locks.c b/fs/locks.c
index dd290a87f58e..7f4ccc7974bc 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1703,7 +1703,7 @@ EXPORT_SYMBOL(lease_get_mtime);
  *	XXX: sfr & willy disagree over whether F_INPROGRESS
  *	should be returned to userspace.
  */
-int fcntl_getlease(struct file *filp)
+static int __fcntl_getlease(struct file *filp, unsigned int flavor)
 {
 	struct file_lease *fl;
 	struct inode *inode = file_inode(filp);
@@ -1719,7 +1719,8 @@ int fcntl_getlease(struct file *filp)
 		list_for_each_entry(fl, &ctx->flc_lease, c.flc_list) {
 			if (fl->c.flc_file != filp)
 				continue;
-			type = target_leasetype(fl);
+			if (fl->c.flc_flags & flavor)
+				type = target_leasetype(fl);
 			break;
 		}
 		spin_unlock(&ctx->flc_lock);
@@ -1730,6 +1731,19 @@ int fcntl_getlease(struct file *filp)
 	return type;
 }
 
+int fcntl_getlease(struct file *filp)
+{
+	return __fcntl_getlease(filp, FL_LEASE);
+}
+
+int fcntl_getdeleg(struct file *filp, struct delegation *deleg)
+{
+	if (deleg->d_flags != 0 || deleg->__pad != 0)
+		return -EINVAL;
+	deleg->d_type = __fcntl_getlease(filp, FL_DELEG);
+	return 0;
+}
+
 /**
  * check_conflicting_open - see if the given file points to an inode that has
  *			    an existing open that would conflict with the
@@ -2039,13 +2053,13 @@ vfs_setlease(struct file *filp, int arg, struct file_lease **lease, void **priv)
 }
 EXPORT_SYMBOL_GPL(vfs_setlease);
 
-static int do_fcntl_add_lease(unsigned int fd, struct file *filp, int arg)
+static int do_fcntl_add_lease(unsigned int fd, struct file *filp, unsigned int flavor, int arg)
 {
 	struct file_lease *fl;
 	struct fasync_struct *new;
 	int error;
 
-	fl = lease_alloc(filp, FL_LEASE, arg);
+	fl = lease_alloc(filp, flavor, arg);
 	if (IS_ERR(fl))
 		return PTR_ERR(fl);
 
@@ -2081,7 +2095,28 @@ int fcntl_setlease(unsigned int fd, struct file *filp, int arg)
 
 	if (arg == F_UNLCK)
 		return vfs_setlease(filp, F_UNLCK, NULL, (void **)&filp);
-	return do_fcntl_add_lease(fd, filp, arg);
+	return do_fcntl_add_lease(fd, filp, FL_LEASE, arg);
+}
+
+/**
+ *	fcntl_setdeleg	-	sets a delegation on an open file
+ *	@fd: open file descriptor
+ *	@filp: file pointer
+ *	@deleg: delegation request from userland
+ *
+ *	Call this fcntl to establish a delegation on the file.
+ *	Note that you also need to call %F_SETSIG to
+ *	receive a signal when the lease is broken.
+ */
+int fcntl_setdeleg(unsigned int fd, struct file *filp, struct delegation *deleg)
+{
+	/* For now, no flags are supported */
+	if (deleg->d_flags != 0 || deleg->__pad != 0)
+		return -EINVAL;
+
+	if (deleg->d_type == F_UNLCK)
+		return vfs_setlease(filp, F_UNLCK, NULL, (void **)&filp);
+	return do_fcntl_add_lease(fd, filp, FL_DELEG, deleg->d_type);
 }
 
 /**
diff --git a/include/linux/filelock.h b/include/linux/filelock.h
index 208d108df2d7..54b824c05299 100644
--- a/include/linux/filelock.h
+++ b/include/linux/filelock.h
@@ -159,6 +159,8 @@ int fcntl_setlk64(unsigned int, struct file *, unsigned int,
 
 int fcntl_setlease(unsigned int fd, struct file *filp, int arg);
 int fcntl_getlease(struct file *filp);
+int fcntl_setdeleg(unsigned int fd, struct file *filp, struct delegation *deleg);
+int fcntl_getdeleg(struct file *filp, struct delegation *deleg);
 
 static inline bool lock_is_unlock(struct file_lock *fl)
 {
@@ -278,6 +280,16 @@ static inline int fcntl_getlease(struct file *filp)
 	return F_UNLCK;
 }
 
+static inline int fcntl_setdeleg(unsigned int fd, struct file *filp, struct delegation *deleg)
+{
+	return -EINVAL;
+}
+
+static inline int fcntl_getdeleg(struct file *filp, struct delegation *deleg)
+{
+	return -EINVAL;
+}
+
 static inline bool lock_is_unlock(struct file_lock *fl)
 {
 	return false;
diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h
index 3741ea1b73d8..008fac15e573 100644
--- a/include/uapi/linux/fcntl.h
+++ b/include/uapi/linux/fcntl.h
@@ -79,6 +79,17 @@
  */
 #define RWF_WRITE_LIFE_NOT_SET	RWH_WRITE_LIFE_NOT_SET
 
+/* Set/Get delegations */
+#define F_GETDELEG		(F_LINUX_SPECIFIC_BASE + 15)
+#define F_SETDELEG		(F_LINUX_SPECIFIC_BASE + 16)
+
+/* Argument structure for F_GETDELEG and F_SETDELEG */
+struct delegation {
+	uint32_t	d_flags;	/* Must be 0 */
+	uint16_t	d_type;		/* F_RDLCK, F_WRLCK, F_UNLCK */
+	uint16_t	__pad;		/* Must be 0 */
+};
+
 /*
  * Types of directory notifications that may be requested.
  */
-- 
cgit v1.2.3