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: (57 commits)
  tidy the trailing symlinks traversal up
  Turn resolution of trailing symlinks iterative everywhere
  simplify link_path_walk() tail
  Make trailing symlink resolution in path_lookupat() iterative
  update nd->inode in __do_follow_link() instead of after do_follow_link()
  pull handling of one pathname component into a helper
  fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCH
  Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
  readlinkat(), fchownat() and fstatat() with empty relative pathnames
  Allow O_PATH for symlinks
  New kind of open files - "location only".
  ext4: Copy fs UUID to superblock
  ext3: Copy fs UUID to superblock.
  vfs: Export file system uuid via /proc/<pid>/mountinfo
  unistd.h: Add new syscalls numbers to asm-generic
  x86: Add new syscalls for x86_64
  x86: Add new syscalls for x86_32
  fs: Remove i_nlink check from file system link callback
  fs: Don't allow to create hardlink for deleted file
  vfs: Add open by file handle support
  ...

1 files changed, 50 insertions, 5 deletions

diff --git a/fs/file_table.c b/fs/file_table.c
index eb36b6b17e26..74a9544ac770 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -276,11 +276,10 @@ struct file *fget(unsigned int fd)
         rcu_read_lock();
         file = fcheck_files(files, fd);
         if (file) {
-                if (!atomic_long_inc_not_zero(&file->f_count)) {
-                        /* File object ref couldn't be taken */
-                        rcu_read_unlock();
-                        return NULL;
-                }
+                /* File object ref couldn't be taken */
+                if (file->f_mode & FMODE_PATH ||
+                    !atomic_long_inc_not_zero(&file->f_count))
+                        file = NULL;
         }
         rcu_read_unlock();
 
@@ -289,6 +288,25 @@ struct file *fget(unsigned int fd)
 
 EXPORT_SYMBOL(fget);
 
+struct file *fget_raw(unsigned int fd)
+{
+        struct file *file;
+        struct files_struct *files = current->files;
+
+        rcu_read_lock();
+        file = fcheck_files(files, fd);
+        if (file) {
+                /* File object ref couldn't be taken */
+                if (!atomic_long_inc_not_zero(&file->f_count))
+                        file = NULL;
+        }
+        rcu_read_unlock();
+
+        return file;
+}
+
+EXPORT_SYMBOL(fget_raw);
+
 /*
  * Lightweight file lookup - no refcnt increment if fd table isn't shared.
  *
@@ -313,6 +331,33 @@ struct file *fget_light(unsigned int fd, int *fput_needed)
         *fput_needed = 0;
         if (atomic_read(&files->count) == 1) {
                 file = fcheck_files(files, fd);
+                if (file && (file->f_mode & FMODE_PATH))
+                        file = NULL;
+        } else {
+                rcu_read_lock();
+                file = fcheck_files(files, fd);
+                if (file) {
+                        if (!(file->f_mode & FMODE_PATH) &&
+                            atomic_long_inc_not_zero(&file->f_count))
+                                *fput_needed = 1;
+                        else
+                                /* Didn't get the reference, someone's freed */
+                                file = NULL;
+                }
+                rcu_read_unlock();
+        }
+
+        return file;
+}
+
+struct file *fget_raw_light(unsigned int fd, int *fput_needed)
+{
+        struct file *file;
+        struct files_struct *files = current->files;
+
+        *fput_needed = 0;
+        if (atomic_read(&files->count) == 1) {
+                file = fcheck_files(files, fd);
         } else {
                 rcu_read_lock();
                 file = fcheck_files(files, fd);