Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs updates from Al Viro:
 "In this pile: pathname resolution rewrite.

   - recursion in link_path_walk() is gone.

   - nesting limits on symlinks are gone (the only limit remaining is
     that the total amount of symlinks is no more than 40, no matter how
     nested).

   - "fast" (inline) symlinks are handled without leaving rcuwalk mode.

   - stack footprint (independent of the nesting) is below kilobyte now,
     about on par with what it used to be with one level of nested
     symlinks and ~2.8 times lower than it used to be in the worst case.

   - struct nameidata is entirely private to fs/namei.c now (not even
     opaque pointers are being passed around).

   - ->follow_link() and ->put_link() calling conventions had been
     changed; all in-tree filesystems converted, out-of-tree should be
     able to follow reasonably easily.

     For out-of-tree conversions, see Documentation/filesystems/porting
     for details (and in-tree filesystems for examples of conversion).

  That has sat in -next since mid-May, seems to survive all testing
  without regressions and merges clean with v4.1"

* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (131 commits)
  turn user_{path_at,path,lpath,path_dir}() into static inlines
  namei: move saved_nd pointer into struct nameidata
  inline user_path_create()
  inline user_path_parent()
  namei: trim do_last() arguments
  namei: stash dfd and name into nameidata
  namei: fold path_cleanup() into terminate_walk()
  namei: saner calling conventions for filename_parentat()
  namei: saner calling conventions for filename_create()
  namei: shift nameidata down into filename_parentat()
  namei: make filename_lookup() reject ERR_PTR() passed as name
  namei: shift nameidata inside filename_lookup()
  namei: move putname() call into filename_lookup()
  namei: pass the struct path to store the result down into path_lookupat()
  namei: uninline set_root{,_rcu}()
  namei: be careful with mountpoint crossings in follow_dotdot_rcu()
  Documentation: remove outdated information from automount-support.txt
  get rid of assorted nameidata-related debris
  lustre: kill unused helper
  lustre: kill unused macro (LOOKUP_CONTINUE)
  ...

1 files changed, 22 insertions, 9 deletions

diff --git a/fs/inode.c b/fs/inode.c
index ea37cd17b53f..e8d62688ed91 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -152,6 +152,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
 	inode->i_pipe = NULL;
 	inode->i_bdev = NULL;
 	inode->i_cdev = NULL;
+	inode->i_link = NULL;
 	inode->i_rdev = 0;
 	inode->dirtied_when = 0;
 
@@ -1584,36 +1585,47 @@ static int update_time(struct inode *inode, struct timespec *time, int flags)
  *	This function automatically handles read only file systems and media,
  *	as well as the "noatime" flag and inode specific "noatime" markers.
  */
-void touch_atime(const struct path *path)
+bool atime_needs_update(const struct path *path, struct inode *inode)
 {
 	struct vfsmount *mnt = path->mnt;
-	struct inode *inode = d_inode(path->dentry);
 	struct timespec now;
 
 	if (inode->i_flags & S_NOATIME)
-		return;
+		return false;
 	if (IS_NOATIME(inode))
-		return;
+		return false;
 	if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
-		return;
+		return false;
 
 	if (mnt->mnt_flags & MNT_NOATIME)
-		return;
+		return false;
 	if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
-		return;
+		return false;
 
 	now = current_fs_time(inode->i_sb);
 
 	if (!relatime_need_update(mnt, inode, now))
-		return;
+		return false;
 
 	if (timespec_equal(&inode->i_atime, &now))
+		return false;
+
+	return true;
+}
+
+void touch_atime(const struct path *path)
+{
+	struct vfsmount *mnt = path->mnt;
+	struct inode *inode = d_inode(path->dentry);
+	struct timespec now;
+
+	if (!atime_needs_update(path, inode))
 		return;
 
 	if (!sb_start_write_trylock(inode->i_sb))
 		return;
 
-	if (__mnt_want_write(mnt))
+	if (__mnt_want_write(mnt) != 0)
 		goto skip_update;
 	/*
 	 * File systems can error out when updating inodes if they need to
@@ -1624,6 +1636,7 @@ void touch_atime(const struct path *path)
 	 * We may also fail on filesystems that have the ability to make parts
 	 * of the fs read only, e.g. subvolumes in Btrfs.
 	 */
+	now = current_fs_time(inode->i_sb);
 	update_time(inode, &now, S_ATIME);
 	__mnt_drop_write(mnt);
 skip_update: