nfs: change mkdir inode_operation to return alternate dentry if needed.

mkdir now allows a different dentry to be returned which is sometimes
relevant for nfs.

This patch changes the nfs_rpc_ops mkdir op to return a dentry, and
passes that back to the caller.

The mkdir nfs_rpc_op will return NULL if the original dentry should be
used.  This matches the mkdir inode_operation.

nfs4_do_create() is duplicated to nfs4_do_mkdir() which is changed to
handle the specifics of directories.  Consequently the current special
handling for directories is removed from nfs4_do_create()

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-6-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 101b1098e87b6ef6cd26939451898ac2b7dccca8..bc957487f6ecf991aa7ce2fb60226224887a9b91 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2426,7 +2426,7 @@ struct dentry *nfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
                         struct dentry *dentry, umode_t mode)
 {
        struct iattr attr;
-       int error;
+       struct dentry *ret;
 
        dfprintk(VFS, "NFS: mkdir(%s/%lu), %pd\n",
                        dir->i_sb->s_id, dir->i_ino, dentry);
@@ -2435,14 +2435,9 @@ struct dentry *nfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
        attr.ia_mode = mode | S_IFDIR;
 
        trace_nfs_mkdir_enter(dir, dentry);
-       error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
-       trace_nfs_mkdir_exit(dir, dentry, error);
-       if (error != 0)
-               goto out_err;
-       return NULL;
-out_err:
-       d_drop(dentry);
-       return ERR_PTR(error);
+       ret = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
+       trace_nfs_mkdir_exit(dir, dentry, PTR_ERR_OR_ZERO(ret));
+       return ret;
 }
 EXPORT_SYMBOL_GPL(nfs_mkdir);
 

diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 0c3bc98cd999cc39a0a883102a83a8b35b57c30d..755ed3c37051da6203ad2f230636769b614f5d0c 100644 (file)
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -578,13 +578,13 @@ out:
        return status;
 }
 
-static int
+static struct dentry *
 nfs3_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
 {
        struct posix_acl *default_acl, *acl;
        struct nfs3_createdata *data;
-       struct dentry *d_alias;
-       int status = -ENOMEM;
+       struct dentry *ret = ERR_PTR(-ENOMEM);
+       int status;
 
        dprintk("NFS call  mkdir %pd\n", dentry);
 
@@ -592,8 +592,9 @@ nfs3_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
        if (data == NULL)
                goto out;
 
-       status = posix_acl_create(dir, &sattr->ia_mode, &default_acl, &acl);
-       if (status)
+       ret = ERR_PTR(posix_acl_create(dir, &sattr->ia_mode,
+                                      &default_acl, &acl));
+       if (IS_ERR(ret))
                goto out;
 
        data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_MKDIR];
@@ -602,25 +603,27 @@ nfs3_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
        data->arg.mkdir.len = dentry->d_name.len;
        data->arg.mkdir.sattr = sattr;
 
-       d_alias = nfs3_do_create(dir, dentry, data);
-       status = PTR_ERR_OR_ZERO(d_alias);
+       ret = nfs3_do_create(dir, dentry, data);
 
-       if (status != 0)
+       if (IS_ERR(ret))
                goto out_release_acls;
 
-       if (d_alias)
-               dentry = d_alias;
+       if (ret)
+               dentry = ret;
 
        status = nfs3_proc_setacls(d_inode(dentry), acl, default_acl);
+       if (status) {
+               dput(ret);
+               ret = ERR_PTR(status);
+       }
 
-       dput(d_alias);
 out_release_acls:
        posix_acl_release(acl);
        posix_acl_release(default_acl);
 out:
        nfs3_free_createdata(data);
-       dprintk("NFS reply mkdir: %d\n", status);
-       return status;
+       dprintk("NFS reply mkdir: %d\n", PTR_ERR_OR_ZERO(ret));
+       return ret;
 }
 
 static int

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0a46b193f18e35e0faeb6d99d42872ebc65857b5..d5ce5256b47afa59977737ec9a51775a80a16da7 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5133,9 +5133,6 @@ static int nfs4_do_create(struct inode *dir, struct dentry *dentry, struct nfs4_
                                    &data->arg.seq_args, &data->res.seq_res, 1);
        if (status == 0) {
                spin_lock(&dir->i_lock);
-               /* Creating a directory bumps nlink in the parent */
-               if (data->arg.ftype == NF4DIR)
-                       nfs4_inc_nlink_locked(dir);
                nfs4_update_changeattr_locked(dir, &data->res.dir_cinfo,
                                              data->res.fattr->time_start,
                                              NFS_INO_INVALID_DATA);
@@ -5145,6 +5142,25 @@ static int nfs4_do_create(struct inode *dir, struct dentry *dentry, struct nfs4_
        return status;
 }
 
+static struct dentry *nfs4_do_mkdir(struct inode *dir, struct dentry *dentry,
+                                   struct nfs4_createdata *data)
+{
+       int status = nfs4_call_sync(NFS_SERVER(dir)->client, NFS_SERVER(dir), &data->msg,
+                                   &data->arg.seq_args, &data->res.seq_res, 1);
+
+       if (status)
+               return ERR_PTR(status);
+
+       spin_lock(&dir->i_lock);
+       /* Creating a directory bumps nlink in the parent */
+       nfs4_inc_nlink_locked(dir);
+       nfs4_update_changeattr_locked(dir, &data->res.dir_cinfo,
+                                     data->res.fattr->time_start,
+                                     NFS_INO_INVALID_DATA);
+       spin_unlock(&dir->i_lock);
+       return nfs_add_or_obtain(dentry, data->res.fh, data->res.fattr);
+}
+
 static void nfs4_free_createdata(struct nfs4_createdata *data)
 {
        nfs4_label_free(data->fattr.label);
@@ -5201,32 +5217,34 @@ static int nfs4_proc_symlink(struct inode *dir, struct dentry *dentry,
        return err;
 }
 
-static int _nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
-               struct iattr *sattr, struct nfs4_label *label)
+static struct dentry *_nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
+                                      struct iattr *sattr,
+                                      struct nfs4_label *label)
 {
        struct nfs4_createdata *data;
-       int status = -ENOMEM;
+       struct dentry *ret = ERR_PTR(-ENOMEM);
 
        data = nfs4_alloc_createdata(dir, &dentry->d_name, sattr, NF4DIR);
        if (data == NULL)
                goto out;
 
        data->arg.label = label;
-       status = nfs4_do_create(dir, dentry, data);
+       ret = nfs4_do_mkdir(dir, dentry, data);
 
        nfs4_free_createdata(data);
 out:
-       return status;
+       return ret;
 }
 
-static int nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
-               struct iattr *sattr)
+static struct dentry *nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
+                                     struct iattr *sattr)
 {
        struct nfs_server *server = NFS_SERVER(dir);
        struct nfs4_exception exception = {
                .interruptible = true,
        };
        struct nfs4_label l, *label;
+       struct dentry *alias;
        int err;
 
        label = nfs4_label_init_security(dir, dentry, sattr, &l);
@@ -5234,14 +5252,15 @@ static int nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
        if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK))
                sattr->ia_mode &= ~current_umask();
        do {
-               err = _nfs4_proc_mkdir(dir, dentry, sattr, label);
+               alias = _nfs4_proc_mkdir(dir, dentry, sattr, label);
+               err = PTR_ERR_OR_ZERO(alias);
                trace_nfs4_mkdir(dir, &dentry->d_name, err);
                err = nfs4_handle_exception(NFS_SERVER(dir), err,
                                &exception);
        } while (exception.retry);
        nfs4_label_release_security(label);
 
-       return err;
+       return alias;
 }
 
 static int _nfs4_proc_readdir(struct nfs_readdir_arg *nr_arg,

diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 77920a2e3cef51073115c217d510064a5f94fb43..63e71310b9f69b8bffbac5155351e0875071b322 100644 (file)
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -446,13 +446,14 @@ out:
        return status;
 }
 
-static int
+static struct dentry *
 nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
 {
        struct nfs_createdata *data;
        struct rpc_message msg = {
                .rpc_proc       = &nfs_procedures[NFSPROC_MKDIR],
        };
+       struct dentry *alias = NULL;
        int status = -ENOMEM;
 
        dprintk("NFS call  mkdir %pd\n", dentry);
@@ -464,12 +465,15 @@ nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
 
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        nfs_mark_for_revalidate(dir);
-       if (status == 0)
-               status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
+       if (status == 0) {
+               alias = nfs_add_or_obtain(dentry, data->res.fh, data->res.fattr);
+               status = PTR_ERR_OR_ZERO(alias);
+       } else
+               alias = ERR_PTR(status);
        nfs_free_createdata(data);
 out:
        dprintk("NFS reply mkdir: %d\n", status);
-       return status;
+       return alias;
 }
 
 static int

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 9155a6ffc3709e2adceaac0ee03488dc030209eb..d66c61cbbd1d0ae3e69ee6e152871908e9413557 100644 (file)
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1802,7 +1802,7 @@ struct nfs_rpc_ops {
        int     (*link)    (struct inode *, struct inode *, const struct qstr *);
        int     (*symlink) (struct inode *, struct dentry *, struct folio *,
                            unsigned int, struct iattr *);
-       int     (*mkdir)   (struct inode *, struct dentry *, struct iattr *);
+       struct dentry *(*mkdir)   (struct inode *, struct dentry *, struct iattr *);
        int     (*rmdir)   (struct inode *, const struct qstr *);
        int     (*readdir) (struct nfs_readdir_arg *, struct nfs_readdir_res *);
        int     (*mknod)   (struct inode *, struct dentry *, struct iattr *,