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

Pull vfs changes from Al Viro.
 "A lot of misc stuff.  The obvious groups:
   * Miklos' atomic_open series; kills the damn abuse of
     ->d_revalidate() by NFS, which was the major stumbling block for
     all work in that area.
   * ripping security_file_mmap() and dealing with deadlocks in the
     area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in
     general.
   * ->encode_fh() switched to saner API; insane fake dentry in
     mm/cleancache.c gone.
   * assorted annotations in fs (endianness, __user)
   * parts of Artem's ->s_dirty work (jff2 and reiserfs parts)
   * ->update_time() work from Josef.
   * other bits and pieces all over the place.

  Normally it would've been in two or three pull requests, but
  signal.git stuff had eaten a lot of time during this cycle ;-/"

Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the
'truncate_range' inode method was removed by the VM changes, the VFS
update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due
to sparse fix added twice, with other changes nearby).

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits)
  nfs: don't open in ->d_revalidate
  vfs: retry last component if opening stale dentry
  vfs: nameidata_to_filp(): don't throw away file on error
  vfs: nameidata_to_filp(): inline __dentry_open()
  vfs: do_dentry_open(): don't put filp
  vfs: split __dentry_open()
  vfs: do_last() common post lookup
  vfs: do_last(): add audit_inode before open
  vfs: do_last(): only return EISDIR for O_CREAT
  vfs: do_last(): check LOOKUP_DIRECTORY
  vfs: do_last(): make ENOENT exit RCU safe
  vfs: make follow_link check RCU safe
  vfs: do_last(): use inode variable
  vfs: do_last(): inline walk_component()
  vfs: do_last(): make exit RCU safe
  vfs: split do_lookup()
  Btrfs: move over to use ->update_time
  fs: introduce inode operation ->update_time
  reiserfs: get rid of resierfs_sync_super
  reiserfs: mark the superblock as dirty a bit later
  ...

1 files changed, 19 insertions, 14 deletions

diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index b05acb79613..b0201ca6e9c 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -304,24 +304,23 @@ out:
 
 /**
  * export_encode_fh - default export_operations->encode_fh function
- * @dentry:  the dentry to encode
+ * @inode:   the object to encode
  * @fh:      where to store the file handle fragment
  * @max_len: maximum length to store there
- * @connectable: whether to store parent information
+ * @parent:  parent directory inode, if wanted
  *
  * This default encode_fh function assumes that the 32 inode number
  * is suitable for locating an inode, and that the generation number
  * can be used to check that it is still valid.  It places them in the
  * filehandle fragment where export_decode_fh expects to find them.
  */
-static int export_encode_fh(struct dentry *dentry, struct fid *fid,
-		int *max_len, int connectable)
+static int export_encode_fh(struct inode *inode, struct fid *fid,
+		int *max_len, struct inode *parent)
 {
-	struct inode * inode = dentry->d_inode;
 	int len = *max_len;
 	int type = FILEID_INO32_GEN;
 
-	if (connectable && (len < 4)) {
+	if (parent && (len < 4)) {
 		*max_len = 4;
 		return 255;
 	} else if (len < 2) {
@@ -332,14 +331,9 @@ static int export_encode_fh(struct dentry *dentry, struct fid *fid,
 	len = 2;
 	fid->i32.ino = inode->i_ino;
 	fid->i32.gen = inode->i_generation;
-	if (connectable && !S_ISDIR(inode->i_mode)) {
-		struct inode *parent;
-
-		spin_lock(&dentry->d_lock);
-		parent = dentry->d_parent->d_inode;
+	if (parent) {
 		fid->i32.parent_ino = parent->i_ino;
 		fid->i32.parent_gen = parent->i_generation;
-		spin_unlock(&dentry->d_lock);
 		len = 4;
 		type = FILEID_INO32_GEN_PARENT;
 	}
@@ -352,11 +346,22 @@ int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len,
 {
 	const struct export_operations *nop = dentry->d_sb->s_export_op;
 	int error;
+	struct dentry *p = NULL;
+	struct inode *inode = dentry->d_inode, *parent = NULL;
 
+	if (connectable && !S_ISDIR(inode->i_mode)) {
+		p = dget_parent(dentry);
+		/*
+		 * note that while p might've ceased to be our parent already,
+		 * it's still pinned by and still positive.
+		 */
+		parent = p->d_inode;
+	}
 	if (nop->encode_fh)
-		error = nop->encode_fh(dentry, fid->raw, max_len, connectable);
+		error = nop->encode_fh(inode, fid->raw, max_len, parent);
 	else
-		error = export_encode_fh(dentry, fid, max_len, connectable);
+		error = export_encode_fh(inode, fid, max_len, parent);
+	dput(p);
 
 	return error;
 }