take close-on-exec logics to fs/file.c, clean it up a bit
Al Viro [Tue, 21 Aug 2012 13:56:33 +0000 (09:56 -0400)]
... and add cond_resched() there, while we are at it.  We can
get large latencies as is...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/exec.c
fs/file.c
include/linux/fdtable.h

index 574cf4d..f2b6af5 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1006,40 +1006,6 @@ no_thread_group:
        return 0;
 }
 
-/*
- * These functions flushes out all traces of the currently running executable
- * so that a new one can be started
- */
-static void flush_old_files(struct files_struct * files)
-{
-       long j = -1;
-       struct fdtable *fdt;
-
-       spin_lock(&files->file_lock);
-       for (;;) {
-               unsigned long set, i;
-
-               j++;
-               i = j * BITS_PER_LONG;
-               fdt = files_fdtable(files);
-               if (i >= fdt->max_fds)
-                       break;
-               set = fdt->close_on_exec[j];
-               if (!set)
-                       continue;
-               fdt->close_on_exec[j] = 0;
-               spin_unlock(&files->file_lock);
-               for ( ; set ; i++,set >>= 1) {
-                       if (set & 1) {
-                               sys_close(i);
-                       }
-               }
-               spin_lock(&files->file_lock);
-
-       }
-       spin_unlock(&files->file_lock);
-}
-
 char *get_task_comm(char *buf, struct task_struct *tsk)
 {
        /* buf must be at least sizeof(tsk->comm) in size */
@@ -1050,6 +1016,11 @@ char *get_task_comm(char *buf, struct task_struct *tsk)
 }
 EXPORT_SYMBOL_GPL(get_task_comm);
 
+/*
+ * These functions flushes out all traces of the currently running executable
+ * so that a new one can be started
+ */
+
 void set_task_comm(struct task_struct *tsk, char *buf)
 {
        task_lock(tsk);
@@ -1171,7 +1142,7 @@ void setup_new_exec(struct linux_binprm * bprm)
        current->self_exec_id++;
                        
        flush_signal_handlers(current, 0);
-       flush_old_files(current->files);
+       do_close_on_exec(current->files);
 }
 EXPORT_SYMBOL(setup_new_exec);
 
index fd4694e..92197dd 100644 (file)
--- a/fs/file.c
+++ b/fs/file.c
@@ -652,6 +652,43 @@ out_unlock:
        return -EBADF;
 }
 
+void do_close_on_exec(struct files_struct *files)
+{
+       unsigned i;
+       struct fdtable *fdt;
+
+       /* exec unshares first */
+       BUG_ON(atomic_read(&files->count) != 1);
+       spin_lock(&files->file_lock);
+       for (i = 0; ; i++) {
+               unsigned long set;
+               unsigned fd = i * BITS_PER_LONG;
+               fdt = files_fdtable(files);
+               if (fd >= fdt->max_fds)
+                       break;
+               set = fdt->close_on_exec[i];
+               if (!set)
+                       continue;
+               fdt->close_on_exec[i] = 0;
+               for ( ; set ; fd++, set >>= 1) {
+                       struct file *file;
+                       if (!(set & 1))
+                               continue;
+                       file = fdt->fd[fd];
+                       if (!file)
+                               continue;
+                       rcu_assign_pointer(fdt->fd[fd], NULL);
+                       __put_unused_fd(files, fd);
+                       spin_unlock(&files->file_lock);
+                       filp_close(file, files);
+                       cond_resched();
+                       spin_lock(&files->file_lock);
+               }
+
+       }
+       spin_unlock(&files->file_lock);
+}
+
 struct file *fget(unsigned int fd)
 {
        struct file *file;
index 59488f2..ef4b213 100644 (file)
@@ -118,6 +118,7 @@ void put_files_struct(struct files_struct *fs);
 void reset_files_struct(struct files_struct *);
 int unshare_files(struct files_struct **);
 struct files_struct *dup_fd(struct files_struct *, int *);
+void do_close_on_exec(struct files_struct *);
 
 extern int __alloc_fd(struct files_struct *files,
                      unsigned start, unsigned end, unsigned flags);