[PATCH v3 04/38] vfs: allow mkdir to wait for delegation break on parent
From: Jeff Layton
Date: Wed Sep 24 2025 - 14:08:10 EST
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.
Rename the existing vfs_mkdir to __vfs_mkdir, make it static and add a
new delegated_inode parameter. Add a new exported vfs_mkdir wrapper
around it that passes a NULL pointer for delegated_inode.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
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(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 31bfb3194b4c29a1d6a002449045bf4e4141911d..a57da600ce7523e9e2755b78f75342bf4fa56ef6 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 91dfd02318772fa63050ecf40fa5625ab48ad589..b3dac91efec622261186fbba8e704ae9e782bea0 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)
- 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 72fbe1316ab8831bb4228d573278f32fe52b6b25..00f54c125b102856c33ffff24627475f40dcbc7b 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -517,7 +517,7 @@ 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 eef5124885e372ac020d2923692116c5e884b3cf..dd5240ce8ad41f02367a54ddf1b6ac0aa28e9721 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) {
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 cd517eb232317d326e6d2fc5a60cb4c7569a137d..c939a58f16f9c4edded424475aff52f2c423d301 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4320,10 +4320,11 @@ 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 victim inode, if the inode is delegated.
*
* Create a directory.
*
@@ -4340,7 +4341,8 @@ 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 inode **delegated_inode)
{
int error;
unsigned max_links = dir->i_sb->s_max_links;
@@ -4363,6 +4365,10 @@ 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))
@@ -4386,6 +4392,7 @@ 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);
@@ -4397,11 +4404,16 @@ int do_mkdirat(int dfd, struct filename *name, umode_t mode)
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);
}
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 b1005abcb9035b2cf743200808a251b00af7e3f4..423dd102b51198ea7c447be2b9a0a5020c950dba 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -202,7 +202,7 @@ 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 2026431500ecbc0cf5fb5d4af1a7632c611ce4f4..6f1275fdc8ac831aa0ea8da588f751eddff88df1 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1560,7 +1560,7 @@ 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 bb0d7ded8e763a4a7a6fc506d966ed2f3bdb4f06..4a3a22f422c37d45e49a762cd3c9957aa2c6a485 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 04539037108c93e285f4e9d6aa61f93a507ae5da..b0fb73b277876a56797f5cc8a5aa53f156bb7a26 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -229,7 +229,7 @@ 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 9c12cb8442311ca26b169e4d1567939ae44a5be0..91c9d07b97f306f57aebb9b69ba564b0c2cb8c17 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 74f2bfc519263c6411a8e3427e1bd6680a1121db..24a091509f12ce65a2c8343d438fccf423d3062b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1997,7 +1997,7 @@ 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 inode **);
int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
umode_t, dev_t);
int vfs_symlink(struct mnt_idmap *, struct inode *,
--
2.51.0