1 files changed, 33 insertions, 14 deletions

diff --git a/fs/file.c b/fs/file.c
index db25c2bdfe46..b61293badfb1 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -497,7 +497,7 @@ repeat:
         error = fd;
 #if 1
         /* Sanity check */
-        if (rcu_dereference_raw(fdt->fd[fd]) != NULL) {
+        if (rcu_access_pointer(fdt->fd[fd]) != NULL) {
                 printk(KERN_WARNING "alloc_fd: slot %d not NULL!\n", fd);
                 rcu_assign_pointer(fdt->fd[fd], NULL);
         }
@@ -683,35 +683,54 @@ EXPORT_SYMBOL(fget_raw);
  * The fput_needed flag returned by fget_light should be passed to the
  * corresponding fput_light.
  */
-struct file *__fget_light(unsigned int fd, fmode_t mask, int *fput_needed)
+static unsigned long __fget_light(unsigned int fd, fmode_t mask)
 {
         struct files_struct *files = current->files;
         struct file *file;
 
-        *fput_needed = 0;
         if (atomic_read(&files->count) == 1) {
                 file = __fcheck_files(files, fd);
-                if (file && (file->f_mode & mask))
-                        file = NULL;
+                if (!file || unlikely(file->f_mode & mask))
+                        return 0;
+                return (unsigned long)file;
         } else {
                 file = __fget(fd, mask);
-                if (file)
-                        *fput_needed = 1;
+                if (!file)
+                        return 0;
+                return FDPUT_FPUT | (unsigned long)file;
         }
-
-        return file;
 }
-struct file *fget_light(unsigned int fd, int *fput_needed)
+unsigned long __fdget(unsigned int fd)
 {
-        return __fget_light(fd, FMODE_PATH, fput_needed);
+        return __fget_light(fd, FMODE_PATH);
 }
-EXPORT_SYMBOL(fget_light);
+EXPORT_SYMBOL(__fdget);
 
-struct file *fget_raw_light(unsigned int fd, int *fput_needed)
+unsigned long __fdget_raw(unsigned int fd)
 {
-        return __fget_light(fd, 0, fput_needed);
+        return __fget_light(fd, 0);
 }
 
+unsigned long __fdget_pos(unsigned int fd)
+{
+        unsigned long v = __fdget(fd);
+        struct file *file = (struct file *)(v & ~3);
+
+        if (file && (file->f_mode & FMODE_ATOMIC_POS)) {
+                if (file_count(file) > 1) {
+                        v |= FDPUT_POS_UNLOCK;
+                        mutex_lock(&file->f_pos_lock);
+                }
+        }
+        return v;
+}
+
+/*
+ * We only lock f_pos if we have threads or if the file might be
+ * shared with another process. In both cases we'll have an elevated
+ * file count (done either by fdget() or by fork()).
+ */
+
 void set_close_on_exec(unsigned int fd, int flag)
 {
         struct files_struct *files = current->files;