Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  FS: lookup_mnt() is only used in the core fs routines now
  bfs: fix bitmap size argument to find_first_zero_bit()
  fs: Use BUG_ON(!mnt) at dentry_open().
  fs: devpts_pty_new() return -ENOMEM if dentry allocation failed
  nfs: lock() vs unlock() typo
  pstore: fix leaking ->i_private
  introduce sys_syncfs to sync a single file system
  Small typo fix...
  Filesystem: fifo: Fixed coding style issue.
  fs/inode: Fix kernel-doc format for inode_init_owner
  select: remove unused MAX_SELECT_SECONDS
  vfs: cleanup do_vfs_ioctl()

1 files changed, 24 insertions, 0 deletions

diff --git a/fs/sync.c b/fs/sync.c
index ba76b9623e7e..92ca208777d5 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -7,6 +7,7 @@
 #include <linux/fs.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/namei.h>
 #include <linux/sched.h>
 #include <linux/writeback.h>
 #include <linux/syscalls.h>
@@ -128,6 +129,29 @@ void emergency_sync(void)
         }
 }
 
+/*
+ * sync a single super
+ */
+SYSCALL_DEFINE1(syncfs, int, fd)
+{
+        struct file *file;
+        struct super_block *sb;
+        int ret;
+        int fput_needed;
+
+        file = fget_light(fd, &fput_needed);
+        if (!file)
+                return -EBADF;
+        sb = file->f_dentry->d_sb;
+
+        down_read(&sb->s_umount);
+        ret = sync_filesystem(sb);
+        up_read(&sb->s_umount);
+
+        fput_light(file, fput_needed);
+        return ret;
+}
+
 /**
  * vfs_fsync_range - helper to sync a range of data & metadata to disk
  * @file:               file to sync