1 files changed, 25 insertions, 18 deletions

diff --git a/fs/open.c b/fs/open.c
index 4ee2dcc31c28..2fac58c51910 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -24,6 +24,7 @@
 #include <linux/personality.h>
 #include <linux/pagemap.h>
 #include <linux/syscalls.h>
+#include <linux/rcupdate.h>
 
 #include <asm/unistd.h>
 
@@ -842,14 +843,16 @@ int get_unused_fd(void)
 {
         struct files_struct * files = current->files;
         int fd, error;
+        struct fdtable *fdt;
 
         error = -EMFILE;
         spin_lock(&files->file_lock);
 
 repeat:
-        fd = find_next_zero_bit(files->open_fds->fds_bits, 
-                                files->max_fdset, 
-                                files->next_fd);
+        fdt = files_fdtable(files);
+        fd = find_next_zero_bit(fdt->open_fds->fds_bits,
+                                fdt->max_fdset,
+                                fdt->next_fd);
 
         /*
          * N.B. For clone tasks sharing a files structure, this test
@@ -872,14 +875,14 @@ repeat:
                 goto repeat;
         }
 
-        FD_SET(fd, files->open_fds);
-        FD_CLR(fd, files->close_on_exec);
-        files->next_fd = fd + 1;
+        FD_SET(fd, fdt->open_fds);
+        FD_CLR(fd, fdt->close_on_exec);
+        fdt->next_fd = fd + 1;
 #if 1
         /* Sanity check */
-        if (files->fd[fd] != NULL) {
+        if (fdt->fd[fd] != NULL) {
                 printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
-                files->fd[fd] = NULL;
+                fdt->fd[fd] = NULL;
         }
 #endif
         error = fd;
@@ -893,9 +896,10 @@ EXPORT_SYMBOL(get_unused_fd);
 
 static inline void __put_unused_fd(struct files_struct *files, unsigned int fd)
 {
-        __FD_CLR(fd, files->open_fds);
-        if (fd < files->next_fd)
-                files->next_fd = fd;
+        struct fdtable *fdt = files_fdtable(files);
+        __FD_CLR(fd, fdt->open_fds);
+        if (fd < fdt->next_fd)
+                fdt->next_fd = fd;
 }
 
 void fastcall put_unused_fd(unsigned int fd)
@@ -924,10 +928,11 @@ EXPORT_SYMBOL(put_unused_fd);
 void fastcall fd_install(unsigned int fd, struct file * file)
 {
         struct files_struct *files = current->files;
+        struct fdtable *fdt;
         spin_lock(&files->file_lock);
-        if (unlikely(files->fd[fd] != NULL))
-                BUG();
-        files->fd[fd] = file;
+        fdt = files_fdtable(files);
+        BUG_ON(fdt->fd[fd] != NULL);
+        rcu_assign_pointer(fdt->fd[fd], file);
         spin_unlock(&files->file_lock);
 }
 
@@ -1010,15 +1015,17 @@ asmlinkage long sys_close(unsigned int fd)
 {
         struct file * filp;
         struct files_struct *files = current->files;
+        struct fdtable *fdt;
 
         spin_lock(&files->file_lock);
-        if (fd >= files->max_fds)
+        fdt = files_fdtable(files);
+        if (fd >= fdt->max_fds)
                 goto out_unlock;
-        filp = files->fd[fd];
+        filp = fdt->fd[fd];
         if (!filp)
                 goto out_unlock;
-        files->fd[fd] = NULL;
-        FD_CLR(fd, files->close_on_exec);
+        rcu_assign_pointer(fdt->fd[fd], NULL);
+        FD_CLR(fd, fdt->close_on_exec);
         __put_unused_fd(files, fd);
         spin_unlock(&files->file_lock);
         return filp_close(filp, files);