1 files changed, 56 insertions, 8 deletions

diff --git a/fs/file.c b/fs/file.c
index abb8b7081d7a..1b8ff05e8311 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -10,6 +10,7 @@
 #include <linux/syscalls.h>
 #include <linux/export.h>
 #include <linux/fs.h>
+#include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/slab.h>
@@ -620,12 +621,9 @@ void fd_install(unsigned int fd, struct file *file)
 
 EXPORT_SYMBOL(fd_install);
 
-/*
- * The same warnings as for __alloc_fd()/__fd_install() apply here...
- */
-int __close_fd(struct files_struct *files, unsigned fd)
+static struct file *pick_file(struct files_struct *files, unsigned fd)
 {
-	struct file *file;
+	struct file *file = NULL;
 	struct fdtable *fdt;
 
 	spin_lock(&files->file_lock);
@@ -637,15 +635,65 @@ int __close_fd(struct files_struct *files, unsigned fd)
 		goto out_unlock;
 	rcu_assign_pointer(fdt->fd[fd], NULL);
 	__put_unused_fd(files, fd);
-	spin_unlock(&files->file_lock);
-	return filp_close(file, files);
 
 out_unlock:
 	spin_unlock(&files->file_lock);
-	return -EBADF;
+	return file;
+}
+
+/*
+ * The same warnings as for __alloc_fd()/__fd_install() apply here...
+ */
+int __close_fd(struct files_struct *files, unsigned fd)
+{
+	struct file *file;
+
+	file = pick_file(files, fd);
+	if (!file)
+		return -EBADF;
+
+	return filp_close(file, files);
 }
 EXPORT_SYMBOL(__close_fd); /* for ksys_close() */
 
+/**
+ * __close_range() - Close all file descriptors in a given range.
+ *
+ * @fd:     starting file descriptor to close
+ * @max_fd: last file descriptor to close
+ *
+ * This closes a range of file descriptors. All file descriptors
+ * from @fd up to and including @max_fd are closed.
+ */
+int __close_range(struct files_struct *files, unsigned fd, unsigned max_fd)
+{
+	unsigned int cur_max;
+
+	if (fd > max_fd)
+		return -EINVAL;
+
+	rcu_read_lock();
+	cur_max = files_fdtable(files)->max_fds;
+	rcu_read_unlock();
+
+	/* cap to last valid index into fdtable */
+	cur_max--;
+
+	max_fd = min(max_fd, cur_max);
+	while (fd <= max_fd) {
+		struct file *file;
+
+		file = pick_file(files, fd++);
+		if (!file)
+			continue;
+
+		filp_close(file, files);
+		cond_resched();
+	}
+
+	return 0;
+}
+
 /*
  * variant of __close_fd that gets a ref on the file for later fput.
  * The caller must ensure that filp_close() called on the file, and then