[PATCH v5 11/17] vfs: make vfs_mknod break delegations on parent directory
From: Jeff Layton <jlayton@kernel.org>
Date: 2025-11-05 16:54:47
Also in:
linux-cifs, linux-fsdevel, linux-nfs, linux-unionfs, linux-xfs, lkml, netfs
Subsystem:
driver core, kobjects, debugfs and sysfs, ecrypt file system, filesystems (vfs and infrastructure), kernel nfsd, sunrpc, and lockd servers, networking [general], networking [unix sockets], overlay filesystem, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Tyler Hicks, Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Miklos Szeredi, Amir Goldstein, Linus Torvalds
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> --- 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(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 104025104ef75381984fd94dfbd50feeaa8cdd22..2f576ecf18324f767cd5ac6cbd28adbf9f46b958 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 3341f00dd08753c8feab184dd82b8bfa63d3724a..83f06452476dec4025cc8f50e082ae6ccbbc7914 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 895f8a09a71acfd03e11164e3b441a7d4e2de146..4f02260dd65b0dfcbfbf5812d2ec6a33444a3b1f 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 b20f053374a578d36fb764e0df80fb7db9230dbe..e9616134390fb7f0d09a759be69bf677f8800bc5 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 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode, 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 de5f46f8c6d3ab24fabddeed9bd59adbe7a486df..6684935007b17ed40723ff0a744045fd187ace5e 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 e30441cc9c63ff8b6c055db80be7974501d0023b..afd95721f76ea761cfe7133c3902028550f3e359 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 83b05aec4e10c846d3168018fb62284e45ceb1a8..1a5d86cfafaa97fc89d15cd1a156968b8c3dd377 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 768098dec2310008632558ae928703b37c3cc8ef..db1fd8d6a84c2c7c0d45b43d9c5a936b3d491b7b 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);
--
2.51.1