fuse: support idmap for mkdir/mknod/symlink/create/tmpfile

We have all the infrastructure in place, we just need
to pass an idmapping here.
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/fuse/dir.c

@@ -614,9 +614,9 @@ static void free_ext_value(struct fuse_args *args)
  * If the filesystem doesn't support this, then fall back to separate
  * 'mknod' + 'open' requests.
  */
-static int fuse_create_open(struct inode *dir, struct dentry *entry,
-			    struct file *file, unsigned int flags,
-			    umode_t mode, u32 opcode)
+static int fuse_create_open(struct mnt_idmap *idmap, struct inode *dir,
+			    struct dentry *entry, struct file *file,
+			    unsigned int flags, umode_t mode, u32 opcode)
 {
 	int err;
 	struct inode *inode;
@@ -673,11 +673,11 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 	args.out_args[1].size = sizeof(*outopenp);
 	args.out_args[1].value = outopenp;
 
-	err = get_create_ext(&nop_mnt_idmap, &args, dir, entry, mode);
+	err = get_create_ext(idmap, &args, dir, entry, mode);
 	if (err)
 		goto out_free_ff;
 
-	err = fuse_simple_request(NULL, fm, &args);
+	err = fuse_simple_request(idmap, fm, &args);
 	free_ext_value(&args);
 	if (err)
 		goto out_free_ff;
@@ -734,6 +734,7 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 			    umode_t mode)
 {
 	int err;
+	struct mnt_idmap *idmap = file_mnt_idmap(file);
 	struct fuse_conn *fc = get_fuse_conn(dir);
 	struct dentry *res = NULL;
 
@@ -758,7 +759,7 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 	if (fc->no_create)
 		goto mknod;
 
-	err = fuse_create_open(dir, entry, file, flags, mode, FUSE_CREATE);
+	err = fuse_create_open(idmap, dir, entry, file, flags, mode, FUSE_CREATE);
 	if (err == -ENOSYS) {
 		fc->no_create = 1;
 		goto mknod;
@@ -769,7 +770,7 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 	return err;
 
 mknod:
-	err = fuse_mknod(&nop_mnt_idmap, dir, entry, mode, 0);
+	err = fuse_mknod(idmap, dir, entry, mode, 0);
 	if (err)
 		goto out_dput;
 no_open:
@@ -779,9 +780,9 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 /*
  * Code shared between mknod, mkdir, symlink and link
  */
-static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
-			    struct inode *dir, struct dentry *entry,
-			    umode_t mode)
+static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
+			    struct fuse_args *args, struct inode *dir,
+			    struct dentry *entry, umode_t mode)
 {
 	struct fuse_entry_out outarg;
 	struct inode *inode;
@@ -803,12 +804,12 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
 	args->out_args[0].value = &outarg;
 
 	if (args->opcode != FUSE_LINK) {
-		err = get_create_ext(&nop_mnt_idmap, args, dir, entry, mode);
+		err = get_create_ext(idmap, args, dir, entry, mode);
 		if (err)
 			goto out_put_forget_req;
 	}
 
-	err = fuse_simple_request(NULL, fm, args);
+	err = fuse_simple_request(idmap, fm, args);
 	free_ext_value(args);
 	if (err)
 		goto out_put_forget_req;
@@ -869,13 +870,13 @@ static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	args.in_args[0].value = &inarg;
 	args.in_args[1].size = entry->d_name.len + 1;
 	args.in_args[1].value = entry->d_name.name;
-	return create_new_entry(fm, &args, dir, entry, mode);
+	return create_new_entry(idmap, fm, &args, dir, entry, mode);
 }
 
 static int fuse_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *entry, umode_t mode, bool excl)
 {
-	return fuse_mknod(&nop_mnt_idmap, dir, entry, mode, 0);
+	return fuse_mknod(idmap, dir, entry, mode, 0);
 }
 
 static int fuse_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
@@ -887,7 +888,8 @@ static int fuse_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 	if (fc->no_tmpfile)
 		return -EOPNOTSUPP;
 
-	err = fuse_create_open(dir, file->f_path.dentry, file, file->f_flags, mode, FUSE_TMPFILE);
+	err = fuse_create_open(idmap, dir, file->f_path.dentry, file,
+			       file->f_flags, mode, FUSE_TMPFILE);
 	if (err == -ENOSYS) {
 		fc->no_tmpfile = 1;
 		err = -EOPNOTSUPP;
@@ -914,7 +916,7 @@ static int fuse_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	args.in_args[0].value = &inarg;
 	args.in_args[1].size = entry->d_name.len + 1;
 	args.in_args[1].value = entry->d_name.name;
-	return create_new_entry(fm, &args, dir, entry, S_IFDIR);
+	return create_new_entry(idmap, fm, &args, dir, entry, S_IFDIR);
 }
 
 static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
@@ -930,7 +932,7 @@ static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	args.in_args[0].value = entry->d_name.name;
 	args.in_args[1].size = len;
 	args.in_args[1].value = link;
-	return create_new_entry(fm, &args, dir, entry, S_IFLNK);
+	return create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);
 }
 
 void fuse_flush_time_update(struct inode *inode)
@@ -1124,7 +1126,7 @@ static int fuse_link(struct dentry *entry, struct inode *newdir,
 	args.in_args[0].value = &inarg;
 	args.in_args[1].size = newent->d_name.len + 1;
 	args.in_args[1].value = newent->d_name.name;
-	err = create_new_entry(fm, &args, newdir, newent, inode->i_mode);
+	err = create_new_entry(NULL, fm, &args, newdir, newent, inode->i_mode);
 	if (!err)
 		fuse_update_ctime_in_cache(inode);
 	else if (err == -EINTR)