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>

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index d109e3763a88150bfe64cd2d5564dc9802ef3386..3341f00dd08753c8feab184dd82b8bfa63d3724a 100644 (file)
--- 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 9586c6aba6eae05a9fc3c103b8501d98767bef53..b20f053374a578d36fb764e0df80fb7db9230dbe 100644 (file)
--- 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 30ea7ffa2affdb9a959b0fd15a630de056d6dc3c..2cb972b5ed994d69995146aeeac8651c1c04fa46 100644 (file)
--- 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 464fd54675f3b16fce9ae5f05ad22e0e6b363eb3..de5f46f8c6d3ab24fabddeed9bd59adbe7a486df 100644 (file)
--- 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 e440f58e3ce81e137aabdf00510d839342a19219..92cf2e11781b0efd16fe0b751286ce943ea6b4e2 100644 (file)
--- 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 2bdc434941ebc70f6d4f57cca4f68125112a7bc4..e30441cc9c63ff8b6c055db80be7974501d0023b 100644 (file)
--- 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 83ece2de4b23bf9209137e7ca414a72439b5cc2e..3747851b61c8bad4c00e49866c380c32e9f53a4b 100644 (file)
--- 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 21876ef1fec90181b9878372c7c7e710773aae9f..83b05aec4e10c846d3168018fb62284e45ceb1a8 100644 (file)
--- 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 *,