take close-on-exec logics to fs/file.c, clean it up a bit

... 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>

3 files changed, 44 insertions, 35 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 574cf4de4ec3..f2b6af585d4a 100644
--- 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);
 
diff --git a/fs/file.c b/fs/file.c
index fd4694e688ab..92197dd9fdc8 100644
--- 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;
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index 59488f2392bc..ef4b2137e6bc 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -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);